[v3] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

[PATCH v3] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Marek Maslanka 1 year, 4 months ago

Allow to disable ACPI PM Timer on suspend and enable on resume. A
disabled timer helps optimise power consumption when the system is
suspended. On resume the timer is only reactivated if it was activated
prior to suspend, so unless the ACPI PM timer is enabled in the BIOS,
this won't change anything.

Signed-off-by: Marek Maslanka <mmaslanka@google.com>

---
Changes in v3:
- Add the clocksource_current_cs_name and clocksource_suspend_cs_name to the clocksource.c
- Do not disable the ACPI PM timer if it's selected as the clocksource
- Link to v2: https://lore.kernel.org/lkml/20240703113850.2726539-1-mmaslanka@google.com/
---
---
 drivers/platform/x86/intel/pmc/adl.c  |  2 ++
 drivers/platform/x86/intel/pmc/cnp.c  |  2 ++
 drivers/platform/x86/intel/pmc/core.c | 47 +++++++++++++++++++++++++++
 drivers/platform/x86/intel/pmc/core.h |  8 +++++
 drivers/platform/x86/intel/pmc/icl.c  |  2 ++
 drivers/platform/x86/intel/pmc/mtl.c  |  2 ++
 drivers/platform/x86/intel/pmc/spt.c  |  2 ++
 drivers/platform/x86/intel/pmc/tgl.c  |  2 ++
 include/linux/clocksource.h           |  2 ++
 kernel/time/clocksource.c             | 22 +++++++++++++
 10 files changed, 91 insertions(+)

diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
index e7878558fd909..9d9c07f44ff61 100644
--- a/drivers/platform/x86/intel/pmc/adl.c
+++ b/drivers/platform/x86/intel/pmc/adl.c
@@ -295,6 +295,8 @@ const struct pmc_reg_map adl_reg_map = {
 	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = ADL_NUM_IP_IGN_ALLOWED,
 	.lpm_num_modes = ADL_LPM_NUM_MODES,
 	.lpm_num_maps = ADL_LPM_NUM_MAPS,
diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
index dd72974bf71e2..513c02670c5aa 100644
--- a/drivers/platform/x86/intel/pmc/cnp.c
+++ b/drivers/platform/x86/intel/pmc/cnp.c
@@ -200,6 +200,8 @@ const struct pmc_reg_map cnp_reg_map = {
 	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = CNP_NUM_IP_IGN_ALLOWED,
 	.etr3_offset = ETR3_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 10c96c1a850af..1a435f5ca08c5 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -12,6 +12,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/bitfield.h>
+#include <linux/clocksource.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/dmi.h>
@@ -1171,6 +1172,44 @@ static bool pmc_core_is_pson_residency_enabled(struct pmc_dev *pmcdev)
 	return val == 1;
 }
 
+/*
+ * Enable or disable APCI PM Timer
+ *
+ * @return: Previous APCI PM Timer enabled state
+ */
+static bool pmc_core_enable_apci_pm_timer(struct pmc_dev *pmcdev, bool enable)
+{
+	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
+	const struct pmc_reg_map *map = pmc->map;
+	char cs_name[32];
+	bool state;
+	u32 reg;
+
+	if (!map->acpi_pm_tmr_ctl_offset)
+		return false;
+
+	clocksource_current_cs_name(cs_name, sizeof(cs_name));
+	if (strncmp(cs_name, "acpi_pm", sizeof(cs_name)) == 0)
+		return false;
+
+	clocksource_suspend_cs_name(cs_name, sizeof(cs_name));
+	if (strncmp(cs_name, "acpi_pm", sizeof(cs_name)) == 0)
+		return false;
+
+	mutex_lock(&pmcdev->lock);
+
+	reg = pmc_core_reg_read(pmc, map->acpi_pm_tmr_ctl_offset);
+	state = !(reg & map->acpi_pm_tmr_disable_bit);
+	if (enable)
+		reg &= ~map->acpi_pm_tmr_disable_bit;
+	else
+		reg |= map->acpi_pm_tmr_disable_bit;
+	pmc_core_reg_write(pmc, map->acpi_pm_tmr_ctl_offset, reg);
+
+	mutex_unlock(&pmcdev->lock);
+
+	return state;
+}
 
 static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
 {
@@ -1446,6 +1485,10 @@ static __maybe_unused int pmc_core_suspend(struct device *dev)
 	if (pmcdev->suspend)
 		pmcdev->suspend(pmcdev);
 
+	/* Disable APCI PM Timer */
+	pmcdev->enable_acpi_pm_timer_on_resume =
+		pmc_core_enable_apci_pm_timer(pmcdev, false);
+
 	/* Check if the syspend will actually use S0ix */
 	if (pm_suspend_via_firmware())
 		return 0;
@@ -1500,6 +1543,10 @@ int pmc_core_resume_common(struct pmc_dev *pmcdev)
 	int offset = pmc->map->lpm_status_offset;
 	int i;
 
+	/* Enable APCI PM Timer */
+	if (pmcdev->enable_acpi_pm_timer_on_resume)
+		pmc_core_enable_apci_pm_timer(pmcdev, true);
+
 	/* Check if the syspend used S0ix */
 	if (pm_suspend_via_firmware())
 		return 0;
diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
index 83504c49a0e31..fe1a94f693b63 100644
--- a/drivers/platform/x86/intel/pmc/core.h
+++ b/drivers/platform/x86/intel/pmc/core.h
@@ -67,6 +67,8 @@ struct telem_endpoint;
 #define SPT_PMC_LTR_SCC				0x3A0
 #define SPT_PMC_LTR_ISH				0x3A4
 
+#define SPT_PMC_ACPI_PM_TMR_CTL_OFFSET		0x18FC
+
 /* Sunrise Point: PGD PFET Enable Ack Status Registers */
 enum ppfear_regs {
 	SPT_PMC_XRAM_PPFEAR0A = 0x590,
@@ -147,6 +149,8 @@ enum ppfear_regs {
 #define SPT_PMC_VRIC1_SLPS0LVEN			BIT(13)
 #define SPT_PMC_VRIC1_XTALSDQDIS		BIT(22)
 
+#define SPT_PMC_BIT_ACPI_PM_TMR_DISABLE		BIT(1)
+
 /* Cannonlake Power Management Controller register offsets */
 #define CNP_PMC_SLPS0_DBG_OFFSET		0x10B4
 #define CNP_PMC_PM_CFG_OFFSET			0x1818
@@ -344,6 +348,8 @@ struct pmc_reg_map {
 	const u8  *lpm_reg_index;
 	const u32 pson_residency_offset;
 	const u32 pson_residency_counter_step;
+	const u32 acpi_pm_tmr_ctl_offset;
+	const u32 acpi_pm_tmr_disable_bit;
 };
 
 /**
@@ -417,6 +423,8 @@ struct pmc_dev {
 	u32 die_c6_offset;
 	struct telem_endpoint *punit_ep;
 	struct pmc_info *regmap_list;
+
+	bool enable_acpi_pm_timer_on_resume;
 };
 
 enum pmc_index {
diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c
index 71b0fd6cb7d84..cbbd440544688 100644
--- a/drivers/platform/x86/intel/pmc/icl.c
+++ b/drivers/platform/x86/intel/pmc/icl.c
@@ -46,6 +46,8 @@ const struct pmc_reg_map icl_reg_map = {
 	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = ICL_NUM_IP_IGN_ALLOWED,
 	.etr3_offset = ETR3_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
index c7d15d864039d..91f2fa728f5c8 100644
--- a/drivers/platform/x86/intel/pmc/mtl.c
+++ b/drivers/platform/x86/intel/pmc/mtl.c
@@ -462,6 +462,8 @@ const struct pmc_reg_map mtl_socm_reg_map = {
 	.ppfear_buckets = MTL_SOCM_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.lpm_num_maps = ADL_LPM_NUM_MAPS,
 	.ltr_ignore_max = MTL_SOCM_NUM_IP_IGN_ALLOWED,
 	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c
index ab993a69e33ee..2cd2b3c68e468 100644
--- a/drivers/platform/x86/intel/pmc/spt.c
+++ b/drivers/platform/x86/intel/pmc/spt.c
@@ -130,6 +130,8 @@ const struct pmc_reg_map spt_reg_map = {
 	.ppfear_buckets = SPT_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = SPT_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = SPT_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = SPT_NUM_IP_IGN_ALLOWED,
 	.pm_vric1_offset = SPT_PMC_VRIC1_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
index e0580de180773..371b4e30f1426 100644
--- a/drivers/platform/x86/intel/pmc/tgl.c
+++ b/drivers/platform/x86/intel/pmc/tgl.c
@@ -197,6 +197,8 @@ const struct pmc_reg_map tgl_reg_map = {
 	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = TGL_NUM_IP_IGN_ALLOWED,
 	.lpm_num_maps = TGL_LPM_NUM_MAPS,
 	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 0ad8b550bb4b4..f1953c5687683 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -305,5 +305,7 @@ static inline unsigned int clocksource_get_max_watchdog_retry(void)
 }
 
 void clocksource_verify_percpu(struct clocksource *cs);
+void clocksource_current_cs_name(char *buf, size_t buf_size);
+void clocksource_suspend_cs_name(char *buf, size_t buf_size);
 
 #endif /* _LINUX_CLOCKSOURCE_H */
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index e5b260aa0e02c..e2e2609f7f4b2 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -1320,6 +1320,28 @@ int clocksource_unregister(struct clocksource *cs)
 }
 EXPORT_SYMBOL(clocksource_unregister);
 
+void clocksource_suspend_cs_name(char *buf, size_t buf_size)
+{
+	mutex_lock(&clocksource_mutex);
+
+	buf[0] = '\0';
+	if (suspend_clocksource)
+		strscpy(buf, suspend_clocksource->name, buf_size);
+
+	mutex_unlock(&clocksource_mutex);
+}
+
+void clocksource_current_cs_name(char *buf, size_t buf_size)
+{
+	mutex_lock(&clocksource_mutex);
+
+	buf[0] = '\0';
+	if (curr_clocksource)
+		strscpy(buf, curr_clocksource->name, buf_size);
+
+	mutex_unlock(&clocksource_mutex);
+}
+
 #ifdef CONFIG_SYSFS
 /**
  * current_clocksource_show - sysfs interface for current clocksource
-- 
2.46.0.rc2.264.g509ed76dc8-goog

Re: [PATCH v3] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Thomas Gleixner 1 year, 4 months ago

Marek!

On Tue, Jul 30 2024 at 12:05, Marek Maslanka wrote:
> Allow to disable ACPI PM Timer on suspend and enable on resume. A
> disabled timer helps optimise power consumption when the system is
> suspended. On resume the timer is only reactivated if it was activated
> prior to suspend, so unless the ACPI PM timer is enabled in the BIOS,
> this won't change anything.
>
>  include/linux/clocksource.h           |  2 ++
>  kernel/time/clocksource.c             | 22 +++++++++++++

The changelog is completely silent about the core code change. That's
not how it works.

Add the core code change as a separate patch with a proper justification
and not hide it in the pile of the PMC changes without cc'ing the
relevant maintainers. It's documented how this works, no?

> +/*
> + * Enable or disable APCI PM Timer
> + *
> + * @return: Previous APCI PM Timer enabled state
> + */
> +static bool pmc_core_enable_apci_pm_timer(struct pmc_dev *pmcdev, bool enable)
> +{
> +	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
> +	const struct pmc_reg_map *map = pmc->map;
> +	char cs_name[32];
> +	bool state;
> +	u32 reg;
> +
> +	if (!map->acpi_pm_tmr_ctl_offset)
> +		return false;
> +
> +	clocksource_current_cs_name(cs_name, sizeof(cs_name));
> +	if (strncmp(cs_name, "acpi_pm", sizeof(cs_name)) == 0)
> +		return false;
> +
> +	clocksource_suspend_cs_name(cs_name, sizeof(cs_name));
> +	if (strncmp(cs_name, "acpi_pm", sizeof(cs_name)) == 0)
> +		return false;

How would ACPI/PM ever be selected as a suspend clocksource? It's not
marked CLOCK_SOURCE_SUSPEND_NONSTOP.

There is a reason why clocksources have suspend/resume and
enable/disable callbacks. The latter allow you to turn it completely off
when it is not in use.

Something like the below should work. It's uncompiled, but you get the
idea.

Thanks,

        tglx
---
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -63,12 +63,40 @@ static u64 acpi_pm_read(struct clocksour
 	return (u64)read_pmtmr();
 }
 
+static bool acpi_pm_enabled;
+
+static void (*enable_callback)(bool enable);
+
+bool acpi_pm_register_enable_callback(void (*cb)(bool enable))
+{
+	enable_callback = cb;
+	if (cb)
+		cb(acpi_pm_enabled);
+}
+
+static int acpi_pm_enable(struct clocksource *cs)
+{
+	acpi_pm_enabled = true;
+	if (enable_callback)
+		enable_callback(true);
+	return 0;
+}
+
+static void acpi_pm_disable(struct clocksource *cs)
+{
+	acpi_pm_enabled = false;
+	if (enable_callback)
+		enable_callback(false);
+}
+
 static struct clocksource clocksource_acpi_pm = {
 	.name		= "acpi_pm",
 	.rating		= 200,
 	.read		= acpi_pm_read,
 	.mask		= (u64)ACPI_PM_MASK,
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.enable		= acpi_pm_enable,
+	.disable	= acpi_pm_disable,
 };

Re: [PATCH v3] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Marek Maślanka 1 year, 4 months ago

Hi Thomas

On Tue, Jul 30, 2024 at 6:08 PM Thomas Gleixner <tglx@linutronix.de> wrote:
>
> Marek!
>
> On Tue, Jul 30 2024 at 12:05, Marek Maslanka wrote:
> > Allow to disable ACPI PM Timer on suspend and enable on resume. A
> > disabled timer helps optimise power consumption when the system is
> > suspended. On resume the timer is only reactivated if it was activated
> > prior to suspend, so unless the ACPI PM timer is enabled in the BIOS,
> > this won't change anything.
> >
> >  include/linux/clocksource.h           |  2 ++
> >  kernel/time/clocksource.c             | 22 +++++++++++++
>
> The changelog is completely silent about the core code change. That's
> not how it works.
>
> Add the core code change as a separate patch with a proper justification
> and not hide it in the pile of the PMC changes without cc'ing the
> relevant maintainers. It's documented how this works, no?

Ok

>
> > +/*
> > + * Enable or disable APCI PM Timer
> > + *
> > + * @return: Previous APCI PM Timer enabled state
> > + */
> > +static bool pmc_core_enable_apci_pm_timer(struct pmc_dev *pmcdev, bool enable)
> > +{
> > +     struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
> > +     const struct pmc_reg_map *map = pmc->map;
> > +     char cs_name[32];
> > +     bool state;
> > +     u32 reg;
> > +
> > +     if (!map->acpi_pm_tmr_ctl_offset)
> > +             return false;
> > +
> > +     clocksource_current_cs_name(cs_name, sizeof(cs_name));
> > +     if (strncmp(cs_name, "acpi_pm", sizeof(cs_name)) == 0)
> > +             return false;
> > +
> > +     clocksource_suspend_cs_name(cs_name, sizeof(cs_name));
> > +     if (strncmp(cs_name, "acpi_pm", sizeof(cs_name)) == 0)
> > +             return false;
>
> How would ACPI/PM ever be selected as a suspend clocksource? It's not
> marked CLOCK_SOURCE_SUSPEND_NONSTOP.
>
> There is a reason why clocksources have suspend/resume and
> enable/disable callbacks. The latter allow you to turn it completely off
> when it is not in use.
>
> Something like the below should work. It's uncompiled, but you get the
> idea.
>
> Thanks,
>
>         tglx
> ---
> --- a/drivers/clocksource/acpi_pm.c
> +++ b/drivers/clocksource/acpi_pm.c
> @@ -63,12 +63,40 @@ static u64 acpi_pm_read(struct clocksour
>         return (u64)read_pmtmr();
>  }
>
> +static bool acpi_pm_enabled;
> +
> +static void (*enable_callback)(bool enable);
> +
> +bool acpi_pm_register_enable_callback(void (*cb)(bool enable))
> +{
> +       enable_callback = cb;
> +       if (cb)
> +               cb(acpi_pm_enabled);
> +}
> +
> +static int acpi_pm_enable(struct clocksource *cs)
> +{
> +       acpi_pm_enabled = true;
> +       if (enable_callback)
> +               enable_callback(true);
> +       return 0;
> +}
> +
> +static void acpi_pm_disable(struct clocksource *cs)
> +{
> +       acpi_pm_enabled = false;
> +       if (enable_callback)
> +               enable_callback(false);
> +}
> +
>  static struct clocksource clocksource_acpi_pm = {
>         .name           = "acpi_pm",
>         .rating         = 200,
>         .read           = acpi_pm_read,
>         .mask           = (u64)ACPI_PM_MASK,
>         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
> +       .enable         = acpi_pm_enable,
> +       .disable        = acpi_pm_disable,
>  };
>
Thanks. I'll try do this in that way. But I need to disable/enable
ACPI PM timer only on suspend/resume, so I'll use suspend/resume
callbacks.

Re: [PATCH v3] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Thomas Gleixner 1 year, 4 months ago

Marek!

On Wed, Jul 31 2024 at 16:44, Marek Maślanka wrote:
> On Tue, Jul 30, 2024 at 6:08 PM Thomas Gleixner <tglx@linutronix.de> wrote:
>> On Tue, Jul 30 2024 at 12:05, Marek Maslanka wrote:
>> +static void acpi_pm_disable(struct clocksource *cs)
>> +{
>> +       acpi_pm_enabled = false;
>> +       if (enable_callback)
>> +               enable_callback(false);
>> +}
>> +
>>  static struct clocksource clocksource_acpi_pm = {
>>         .name           = "acpi_pm",
>>         .rating         = 200,
>>         .read           = acpi_pm_read,
>>         .mask           = (u64)ACPI_PM_MASK,
>>         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
>> +       .enable         = acpi_pm_enable,
>> +       .disable        = acpi_pm_disable,
>>  };
>>
> Thanks. I'll try do this in that way. But I need to disable/enable
> ACPI PM timer only on suspend/resume, so I'll use suspend/resume
> callbacks.

Why? What's the point of keeping it running when nothing uses it?

Thanks,

        tglx

Re: [PATCH v3] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Marek Maślanka 1 year, 4 months ago

On Wed, Jul 31, 2024 at 6:33 PM Thomas Gleixner <tglx@linutronix.de> wrote:
>
> Marek!
>
> On Wed, Jul 31 2024 at 16:44, Marek Maślanka wrote:
> > On Tue, Jul 30, 2024 at 6:08 PM Thomas Gleixner <tglx@linutronix.de> wrote:
> >> On Tue, Jul 30 2024 at 12:05, Marek Maslanka wrote:
> >> +static void acpi_pm_disable(struct clocksource *cs)
> >> +{
> >> +       acpi_pm_enabled = false;
> >> +       if (enable_callback)
> >> +               enable_callback(false);
> >> +}
> >> +
> >>  static struct clocksource clocksource_acpi_pm = {
> >>         .name           = "acpi_pm",
> >>         .rating         = 200,
> >>         .read           = acpi_pm_read,
> >>         .mask           = (u64)ACPI_PM_MASK,
> >>         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
> >> +       .enable         = acpi_pm_enable,
> >> +       .disable        = acpi_pm_disable,
> >>  };
> >>
> > Thanks. I'll try do this in that way. But I need to disable/enable
> > ACPI PM timer only on suspend/resume, so I'll use suspend/resume
> > callbacks.
>
> Why? What's the point of keeping it running when nothing uses it?
>
> Thanks,
>
>         tglx

In case of Intel CPUs the watchdog (iTCO/wdat_wdt) is driven by ACPI PM
Timer. But it may also be used by others that I don't know about, so I don't
want to disable it.

Best
Marek

Re: [PATCH v3] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Ilpo Järvinen 1 year, 4 months ago

On Wed, 31 Jul 2024, Marek Maślanka wrote:

> On Wed, Jul 31, 2024 at 6:33 PM Thomas Gleixner <tglx@linutronix.de> wrote:
> >
> > Marek!
> >
> > On Wed, Jul 31 2024 at 16:44, Marek Maślanka wrote:
> > > On Tue, Jul 30, 2024 at 6:08 PM Thomas Gleixner <tglx@linutronix.de> wrote:
> > >> On Tue, Jul 30 2024 at 12:05, Marek Maslanka wrote:
> > >> +static void acpi_pm_disable(struct clocksource *cs)
> > >> +{
> > >> +       acpi_pm_enabled = false;
> > >> +       if (enable_callback)
> > >> +               enable_callback(false);
> > >> +}
> > >> +
> > >>  static struct clocksource clocksource_acpi_pm = {
> > >>         .name           = "acpi_pm",
> > >>         .rating         = 200,
> > >>         .read           = acpi_pm_read,
> > >>         .mask           = (u64)ACPI_PM_MASK,
> > >>         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
> > >> +       .enable         = acpi_pm_enable,
> > >> +       .disable        = acpi_pm_disable,
> > >>  };
> > >>
> > > Thanks. I'll try do this in that way. But I need to disable/enable
> > > ACPI PM timer only on suspend/resume, so I'll use suspend/resume
> > > callbacks.
> >
> > Why? What's the point of keeping it running when nothing uses it?
> >
> > Thanks,
> >
> >         tglx
> 
> In case of Intel CPUs the watchdog (iTCO/wdat_wdt) is driven by ACPI PM
> Timer. But it may also be used by others that I don't know about, so I don't
> want to disable it.

Hi Marek,

This kind of non-obvious information should be put into the changelog 
because it helps if after ten years somebody is looking into this change 
and asks similar why questions.

-- 
 i.

[PATCH v4 1/2] clocksource: acpi_pm: Add external callback for suspend/resume

Posted by Marek Maslanka 1 year, 4 months ago

Provides the capability to register an external callback for the ACPI PM
timer, which is called during the suspend and resume processes.

Signed-off-by: Marek Maslanka <mmaslanka@google.com>

---
Changes in v4:
- No changes as this was introduced as a separated patch after the v3
  review.
- Link to v3: https://lore.kernel.org/lkml/20240730120546.1042515-1-mmaslanka@google.com/
---
---
 drivers/clocksource/acpi_pm.c | 27 +++++++++++++++++++++++++++
 drivers/clocksource/acpi_pm.h | 16 ++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 drivers/clocksource/acpi_pm.h

diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 82338773602ca..c629f5462bc0f 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -25,6 +25,12 @@
 #include <asm/io.h>
 #include <asm/time.h>
 
+#include "acpi_pm.h"
+
+static void *suspend_resume_cb_data;
+
+static void (*suspend_resume_callback)(void *data, bool suspend);
+
 /*
  * The I/O port the PMTMR resides at.
  * The location is detected during setup_arch(),
@@ -58,6 +64,25 @@ u32 acpi_pm_read_verified(void)
 	return v2;
 }
 
+void acpi_pm_register_suspend_resume_callback(void (*cb)(void *data, bool suspend),
+					      void *data)
+{
+	suspend_resume_callback = cb;
+	suspend_resume_cb_data = data;
+}
+
+static void acpi_pm_suspend(struct clocksource *cs)
+{
+	if (suspend_resume_callback)
+		suspend_resume_callback(suspend_resume_cb_data, true);
+}
+
+static void acpi_pm_resume(struct clocksource *cs)
+{
+	if (suspend_resume_callback)
+		suspend_resume_callback(suspend_resume_cb_data, false);
+}
+
 static u64 acpi_pm_read(struct clocksource *cs)
 {
 	return (u64)read_pmtmr();
@@ -69,6 +94,8 @@ static struct clocksource clocksource_acpi_pm = {
 	.read		= acpi_pm_read,
 	.mask		= (u64)ACPI_PM_MASK,
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.suspend	= acpi_pm_suspend,
+	.resume		= acpi_pm_resume,
 };
 
 
diff --git a/drivers/clocksource/acpi_pm.h b/drivers/clocksource/acpi_pm.h
new file mode 100644
index 0000000000000..c932899f04282
--- /dev/null
+++ b/drivers/clocksource/acpi_pm.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ACPI_PM_H__
+#define __ACPI_PM_H__
+
+#include <linux/types.h>
+
+/**
+ * Register callback for suspend and resume event
+ *
+ * @cb Callback triggered on suspend and resume
+ * @data Data passed with the callback
+ */
+void acpi_pm_register_suspend_resume_callback(void (*cb)(void *data, bool suspend),
+					      void *data);
+
+#endif
-- 
2.46.0.76.ge559c4bf1a-goog

Re: [PATCH v4 1/2] clocksource: acpi_pm: Add external callback for suspend/resume

Posted by Thomas Gleixner 1 year, 4 months ago

On Fri, Aug 09 2024 at 13:13, Marek Maslanka wrote:
> --- a/drivers/clocksource/acpi_pm.c
> +++ b/drivers/clocksource/acpi_pm.c
> @@ -25,6 +25,12 @@
>  #include <asm/io.h>
>  #include <asm/time.h>
>  
> +#include "acpi_pm.h"

include/linux/acpi_pmtmr.h please

> +static void *suspend_resume_cb_data;
> +
> +static void (*suspend_resume_callback)(void *data, bool suspend);
> +
>  /*
>   * The I/O port the PMTMR resides at.
>   * The location is detected during setup_arch(),
> @@ -58,6 +64,25 @@ u32 acpi_pm_read_verified(void)
>  	return v2;
>  }
>  
> +void acpi_pm_register_suspend_resume_callback(void (*cb)(void *data, bool suspend),
> +					      void *data)

No line break required. Also the name wants to be acpi_pmtmr_... for the
global visible function so that it can't be confused with the power
management related acpi_pm_* functions

Thanks,

        tglx

[PATCH v5 1/2] clocksource: acpi_pm: Add external callback for suspend/resume

Posted by Marek Maslanka 1 year, 4 months ago

Provides the capability to register an external callback for the ACPI PM
timer, which is called during the suspend and resume processes.

Signed-off-by: Marek Maslanka <mmaslanka@google.com>

---
Changes in v5:
- Rename acpi_pm_register_suspend_resume_callback to
  acpi_pmtmr_register_suspend_resume_callback and move prototype to
  include/linux/acpi_pmtmr.h
- Remove the acpi_pm.h header added in the previous patch.
- Link to v4: https://lore.kernel.org/lkml/20240809131343.1173369-1-mmaslanka@google.com/
---
---
 drivers/clocksource/acpi_pm.c | 24 ++++++++++++++++++++++++
 include/linux/acpi_pmtmr.h    |  8 ++++++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 82338773602ca..fab19b7de55c1 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -25,6 +25,10 @@
 #include <asm/io.h>
 #include <asm/time.h>
 
+static void *suspend_resume_cb_data;
+
+static void (*suspend_resume_callback)(void *data, bool suspend);
+
 /*
  * The I/O port the PMTMR resides at.
  * The location is detected during setup_arch(),
@@ -58,6 +62,24 @@ u32 acpi_pm_read_verified(void)
 	return v2;
 }
 
+void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data)
+{
+	suspend_resume_callback = cb;
+	suspend_resume_cb_data = data;
+}
+
+static void acpi_pm_suspend(struct clocksource *cs)
+{
+	if (suspend_resume_callback)
+		suspend_resume_callback(suspend_resume_cb_data, true);
+}
+
+static void acpi_pm_resume(struct clocksource *cs)
+{
+	if (suspend_resume_callback)
+		suspend_resume_callback(suspend_resume_cb_data, false);
+}
+
 static u64 acpi_pm_read(struct clocksource *cs)
 {
 	return (u64)read_pmtmr();
@@ -69,6 +91,8 @@ static struct clocksource clocksource_acpi_pm = {
 	.read		= acpi_pm_read,
 	.mask		= (u64)ACPI_PM_MASK,
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.suspend	= acpi_pm_suspend,
+	.resume		= acpi_pm_resume,
 };
 
 
diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h
index 50d88bf1498d7..a5262d28b97e0 100644
--- a/include/linux/acpi_pmtmr.h
+++ b/include/linux/acpi_pmtmr.h
@@ -26,6 +26,14 @@ static inline u32 acpi_pm_read_early(void)
 	return acpi_pm_read_verified() & ACPI_PM_MASK;
 }
 
+/**
+ * Register callback for suspend and resume event
+ *
+ * @cb Callback triggered on suspend and resume
+ * @data Data passed with the callback
+ */
+void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data);
+
 #else
 
 static inline u32 acpi_pm_read_early(void)
-- 
2.46.0.76.ge559c4bf1a-goog

Re: [PATCH v5 1/2] clocksource: acpi_pm: Add external callback for suspend/resume

Posted by Hans de Goede 1 year, 4 months ago

Hi,

Thank you for your patch.

On 8/12/24 6:37 AM, Marek Maslanka wrote:
> Provides the capability to register an external callback for the ACPI PM
> timer, which is called during the suspend and resume processes.
> 
> Signed-off-by: Marek Maslanka <mmaslanka@google.com>
> 
> ---
> Changes in v5:
> - Rename acpi_pm_register_suspend_resume_callback to
>   acpi_pmtmr_register_suspend_resume_callback and move prototype to
>   include/linux/acpi_pmtmr.h
> - Remove the acpi_pm.h header added in the previous patch.
> - Link to v4: https://lore.kernel.org/lkml/20240809131343.1173369-1-mmaslanka@google.com/
> ---
> ---
>  drivers/clocksource/acpi_pm.c | 24 ++++++++++++++++++++++++
>  include/linux/acpi_pmtmr.h    |  8 ++++++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
> index 82338773602ca..fab19b7de55c1 100644
> --- a/drivers/clocksource/acpi_pm.c
> +++ b/drivers/clocksource/acpi_pm.c
> @@ -25,6 +25,10 @@
>  #include <asm/io.h>
>  #include <asm/time.h>
>  
> +static void *suspend_resume_cb_data;
> +
> +static void (*suspend_resume_callback)(void *data, bool suspend);
> +
>  /*
>   * The I/O port the PMTMR resides at.
>   * The location is detected during setup_arch(),
> @@ -58,6 +62,24 @@ u32 acpi_pm_read_verified(void)
>  	return v2;
>  }
>  
> +void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data)
> +{
> +	suspend_resume_callback = cb;
> +	suspend_resume_cb_data = data;
> +}

The intel-pmc driver which is a consumer of this symbol can be build as
a module, so this needs a EXPORT_SYMBOL_GPL().

Also the pmc driver can be unbound from its device, or the entire
module can be removed, so this also needs an unregister function
to match, so that the pmc driver can unregister its callback
from pmc_core_remove().

Regards,

Hans



> +
> +static void acpi_pm_suspend(struct clocksource *cs)
> +{
> +	if (suspend_resume_callback)
> +		suspend_resume_callback(suspend_resume_cb_data, true);
> +}
> +
> +static void acpi_pm_resume(struct clocksource *cs)
> +{
> +	if (suspend_resume_callback)
> +		suspend_resume_callback(suspend_resume_cb_data, false);
> +}
> +
>  static u64 acpi_pm_read(struct clocksource *cs)
>  {
>  	return (u64)read_pmtmr();
> @@ -69,6 +91,8 @@ static struct clocksource clocksource_acpi_pm = {
>  	.read		= acpi_pm_read,
>  	.mask		= (u64)ACPI_PM_MASK,
>  	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
> +	.suspend	= acpi_pm_suspend,
> +	.resume		= acpi_pm_resume,
>  };
>  
>  
> diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h
> index 50d88bf1498d7..a5262d28b97e0 100644
> --- a/include/linux/acpi_pmtmr.h
> +++ b/include/linux/acpi_pmtmr.h
> @@ -26,6 +26,14 @@ static inline u32 acpi_pm_read_early(void)
>  	return acpi_pm_read_verified() & ACPI_PM_MASK;
>  }
>  
> +/**
> + * Register callback for suspend and resume event
> + *
> + * @cb Callback triggered on suspend and resume
> + * @data Data passed with the callback
> + */
> +void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data);
> +
>  #else
>  
>  static inline u32 acpi_pm_read_early(void)

[PATCH v6 1/2] clocksource: acpi_pm: Add external callback for suspend/resume

Posted by Marek Maslanka 1 year, 4 months ago

Provides the capability to register an external callback for the ACPI PM
timer, which is called during the suspend and resume processes.

Signed-off-by: Marek Maslanka <mmaslanka@google.com>

---
Changes in v6:
- Add the acpi_pmtmr_unregister_suspend_resume_callback function to remove callback
- Add EXPORT_SYMBOL_GPL to the added functions
- Link to v5: https://lore.kernel.org/lkml/20240812043741.3434744-1-mmaslanka@google.com/
---
---
 drivers/clocksource/acpi_pm.c | 32 ++++++++++++++++++++++++++++++++
 include/linux/acpi_pmtmr.h    | 13 +++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 82338773602ca..b4330a01a566b 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -25,6 +25,10 @@
 #include <asm/io.h>
 #include <asm/time.h>
 
+static void *suspend_resume_cb_data;
+
+static void (*suspend_resume_callback)(void *data, bool suspend);
+
 /*
  * The I/O port the PMTMR resides at.
  * The location is detected during setup_arch(),
@@ -58,6 +62,32 @@ u32 acpi_pm_read_verified(void)
 	return v2;
 }
 
+void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data)
+{
+	suspend_resume_callback = cb;
+	suspend_resume_cb_data = data;
+}
+EXPORT_SYMBOL_GPL(acpi_pmtmr_register_suspend_resume_callback);
+
+void acpi_pmtmr_unregister_suspend_resume_callback(void)
+{
+	suspend_resume_callback = NULL;
+	suspend_resume_cb_data = NULL;
+}
+EXPORT_SYMBOL_GPL(acpi_pmtmr_unregister_suspend_resume_callback);
+
+static void acpi_pm_suspend(struct clocksource *cs)
+{
+	if (suspend_resume_callback)
+		suspend_resume_callback(suspend_resume_cb_data, true);
+}
+
+static void acpi_pm_resume(struct clocksource *cs)
+{
+	if (suspend_resume_callback)
+		suspend_resume_callback(suspend_resume_cb_data, false);
+}
+
 static u64 acpi_pm_read(struct clocksource *cs)
 {
 	return (u64)read_pmtmr();
@@ -69,6 +99,8 @@ static struct clocksource clocksource_acpi_pm = {
 	.read		= acpi_pm_read,
 	.mask		= (u64)ACPI_PM_MASK,
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.suspend	= acpi_pm_suspend,
+	.resume		= acpi_pm_resume,
 };
 
 
diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h
index 50d88bf1498d7..0ded9220d379c 100644
--- a/include/linux/acpi_pmtmr.h
+++ b/include/linux/acpi_pmtmr.h
@@ -26,6 +26,19 @@ static inline u32 acpi_pm_read_early(void)
 	return acpi_pm_read_verified() & ACPI_PM_MASK;
 }
 
+/**
+ * Register callback for suspend and resume event
+ *
+ * @cb Callback triggered on suspend and resume
+ * @data Data passed with the callback
+ */
+void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data);
+
+/**
+ * Remove registered callback for suspend and resume event
+ */
+void acpi_pmtmr_unregister_suspend_resume_callback(void);
+
 #else
 
 static inline u32 acpi_pm_read_early(void)
-- 
2.46.0.76.ge559c4bf1a-goog

Re: [PATCH v6 1/2] clocksource: acpi_pm: Add external callback for suspend/resume

Posted by Hans de Goede 1 year, 4 months ago

Hi,

On 8/12/24 8:41 PM, Marek Maslanka wrote:
> Provides the capability to register an external callback for the ACPI PM
> timer, which is called during the suspend and resume processes.
> 
> Signed-off-by: Marek Maslanka <mmaslanka@google.com>

Daniel / Thomas I believe this series is ready for merging now,
do you want to merge this through the tree for drivers/clocksource ?

Or shall I merge this through the platform-drivers-x86 tree ?

In case of the latter may I please have your Acked-by for patch 1/2 for ths ?

Regards,

Hans


> 
> ---
> Changes in v6:
> - Add the acpi_pmtmr_unregister_suspend_resume_callback function to remove callback
> - Add EXPORT_SYMBOL_GPL to the added functions
> - Link to v5: https://lore.kernel.org/lkml/20240812043741.3434744-1-mmaslanka@google.com/
> ---
> ---
>  drivers/clocksource/acpi_pm.c | 32 ++++++++++++++++++++++++++++++++
>  include/linux/acpi_pmtmr.h    | 13 +++++++++++++
>  2 files changed, 45 insertions(+)
> 
> diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
> index 82338773602ca..b4330a01a566b 100644
> --- a/drivers/clocksource/acpi_pm.c
> +++ b/drivers/clocksource/acpi_pm.c
> @@ -25,6 +25,10 @@
>  #include <asm/io.h>
>  #include <asm/time.h>
>  
> +static void *suspend_resume_cb_data;
> +
> +static void (*suspend_resume_callback)(void *data, bool suspend);
> +
>  /*
>   * The I/O port the PMTMR resides at.
>   * The location is detected during setup_arch(),
> @@ -58,6 +62,32 @@ u32 acpi_pm_read_verified(void)
>  	return v2;
>  }
>  
> +void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data)
> +{
> +	suspend_resume_callback = cb;
> +	suspend_resume_cb_data = data;
> +}
> +EXPORT_SYMBOL_GPL(acpi_pmtmr_register_suspend_resume_callback);
> +
> +void acpi_pmtmr_unregister_suspend_resume_callback(void)
> +{
> +	suspend_resume_callback = NULL;
> +	suspend_resume_cb_data = NULL;
> +}
> +EXPORT_SYMBOL_GPL(acpi_pmtmr_unregister_suspend_resume_callback);
> +
> +static void acpi_pm_suspend(struct clocksource *cs)
> +{
> +	if (suspend_resume_callback)
> +		suspend_resume_callback(suspend_resume_cb_data, true);
> +}
> +
> +static void acpi_pm_resume(struct clocksource *cs)
> +{
> +	if (suspend_resume_callback)
> +		suspend_resume_callback(suspend_resume_cb_data, false);
> +}
> +
>  static u64 acpi_pm_read(struct clocksource *cs)
>  {
>  	return (u64)read_pmtmr();
> @@ -69,6 +99,8 @@ static struct clocksource clocksource_acpi_pm = {
>  	.read		= acpi_pm_read,
>  	.mask		= (u64)ACPI_PM_MASK,
>  	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
> +	.suspend	= acpi_pm_suspend,
> +	.resume		= acpi_pm_resume,
>  };
>  
>  
> diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h
> index 50d88bf1498d7..0ded9220d379c 100644
> --- a/include/linux/acpi_pmtmr.h
> +++ b/include/linux/acpi_pmtmr.h
> @@ -26,6 +26,19 @@ static inline u32 acpi_pm_read_early(void)
>  	return acpi_pm_read_verified() & ACPI_PM_MASK;
>  }
>  
> +/**
> + * Register callback for suspend and resume event
> + *
> + * @cb Callback triggered on suspend and resume
> + * @data Data passed with the callback
> + */
> +void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data);
> +
> +/**
> + * Remove registered callback for suspend and resume event
> + */
> +void acpi_pmtmr_unregister_suspend_resume_callback(void);
> +
>  #else
>  
>  static inline u32 acpi_pm_read_early(void)

Re: [PATCH v6 1/2] clocksource: acpi_pm: Add external callback for suspend/resume

Posted by Daniel Lezcano 1 year, 4 months ago

On 19/08/2024 13:35, Hans de Goede wrote:
> Hi,
> 
> On 8/12/24 8:41 PM, Marek Maslanka wrote:
>> Provides the capability to register an external callback for the ACPI PM
>> timer, which is called during the suspend and resume processes.
>>
>> Signed-off-by: Marek Maslanka <mmaslanka@google.com>
> 
> Daniel / Thomas I believe this series is ready for merging now,
> do you want to merge this through the tree for drivers/clocksource ?
> 
> Or shall I merge this through the platform-drivers-x86 tree ?
> 
> In case of the latter may I please have your Acked-by for patch 1/2 for ths ?


I'll pick them, thanks

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Re: [PATCH v6 1/2] clocksource: acpi_pm: Add external callback for suspend/resume

Posted by Hans de Goede 1 year, 4 months ago

Hi,

On 8/12/24 8:41 PM, Marek Maslanka wrote:
> Provides the capability to register an external callback for the ACPI PM
> timer, which is called during the suspend and resume processes.
> 
> Signed-off-by: Marek Maslanka <mmaslanka@google.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans



> 
> ---
> Changes in v6:
> - Add the acpi_pmtmr_unregister_suspend_resume_callback function to remove callback
> - Add EXPORT_SYMBOL_GPL to the added functions
> - Link to v5: https://lore.kernel.org/lkml/20240812043741.3434744-1-mmaslanka@google.com/
> ---
> ---
>  drivers/clocksource/acpi_pm.c | 32 ++++++++++++++++++++++++++++++++
>  include/linux/acpi_pmtmr.h    | 13 +++++++++++++
>  2 files changed, 45 insertions(+)
> 
> diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
> index 82338773602ca..b4330a01a566b 100644
> --- a/drivers/clocksource/acpi_pm.c
> +++ b/drivers/clocksource/acpi_pm.c
> @@ -25,6 +25,10 @@
>  #include <asm/io.h>
>  #include <asm/time.h>
>  
> +static void *suspend_resume_cb_data;
> +
> +static void (*suspend_resume_callback)(void *data, bool suspend);
> +
>  /*
>   * The I/O port the PMTMR resides at.
>   * The location is detected during setup_arch(),
> @@ -58,6 +62,32 @@ u32 acpi_pm_read_verified(void)
>  	return v2;
>  }
>  
> +void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data)
> +{
> +	suspend_resume_callback = cb;
> +	suspend_resume_cb_data = data;
> +}
> +EXPORT_SYMBOL_GPL(acpi_pmtmr_register_suspend_resume_callback);
> +
> +void acpi_pmtmr_unregister_suspend_resume_callback(void)
> +{
> +	suspend_resume_callback = NULL;
> +	suspend_resume_cb_data = NULL;
> +}
> +EXPORT_SYMBOL_GPL(acpi_pmtmr_unregister_suspend_resume_callback);
> +
> +static void acpi_pm_suspend(struct clocksource *cs)
> +{
> +	if (suspend_resume_callback)
> +		suspend_resume_callback(suspend_resume_cb_data, true);
> +}
> +
> +static void acpi_pm_resume(struct clocksource *cs)
> +{
> +	if (suspend_resume_callback)
> +		suspend_resume_callback(suspend_resume_cb_data, false);
> +}
> +
>  static u64 acpi_pm_read(struct clocksource *cs)
>  {
>  	return (u64)read_pmtmr();
> @@ -69,6 +99,8 @@ static struct clocksource clocksource_acpi_pm = {
>  	.read		= acpi_pm_read,
>  	.mask		= (u64)ACPI_PM_MASK,
>  	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
> +	.suspend	= acpi_pm_suspend,
> +	.resume		= acpi_pm_resume,
>  };
>  
>  
> diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h
> index 50d88bf1498d7..0ded9220d379c 100644
> --- a/include/linux/acpi_pmtmr.h
> +++ b/include/linux/acpi_pmtmr.h
> @@ -26,6 +26,19 @@ static inline u32 acpi_pm_read_early(void)
>  	return acpi_pm_read_verified() & ACPI_PM_MASK;
>  }
>  
> +/**
> + * Register callback for suspend and resume event
> + *
> + * @cb Callback triggered on suspend and resume
> + * @data Data passed with the callback
> + */
> +void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data);
> +
> +/**
> + * Remove registered callback for suspend and resume event
> + */
> +void acpi_pmtmr_unregister_suspend_resume_callback(void);
> +
>  #else
>  
>  static inline u32 acpi_pm_read_early(void)

[tip: timers/core] clocksource: acpi_pm: Add external callback for suspend/resume

Posted by tip-bot2 for Marek Maslanka 1 year, 3 months ago

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     56bd72e9cd8272687aa2a8eccddabc5526cd7845
Gitweb:        https://git.kernel.org/tip/56bd72e9cd8272687aa2a8eccddabc5526cd7845
Author:        Marek Maslanka <mmaslanka@google.com>
AuthorDate:    Mon, 12 Aug 2024 18:41:42 
Committer:     Daniel Lezcano <daniel.lezcano@linaro.org>
CommitterDate: Fri, 06 Sep 2024 14:49:20 +02:00

clocksource: acpi_pm: Add external callback for suspend/resume

Provides the capability to register an external callback for the ACPI PM
timer, which is called during the suspend and resume processes.

Signed-off-by: Marek Maslanka <mmaslanka@google.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240812184150.1079924-1-mmaslanka@google.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/clocksource/acpi_pm.c | 32 ++++++++++++++++++++++++++++++++
 include/linux/acpi_pmtmr.h    | 13 +++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 8233877..b4330a0 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -25,6 +25,10 @@
 #include <asm/io.h>
 #include <asm/time.h>
 
+static void *suspend_resume_cb_data;
+
+static void (*suspend_resume_callback)(void *data, bool suspend);
+
 /*
  * The I/O port the PMTMR resides at.
  * The location is detected during setup_arch(),
@@ -58,6 +62,32 @@ u32 acpi_pm_read_verified(void)
 	return v2;
 }
 
+void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data)
+{
+	suspend_resume_callback = cb;
+	suspend_resume_cb_data = data;
+}
+EXPORT_SYMBOL_GPL(acpi_pmtmr_register_suspend_resume_callback);
+
+void acpi_pmtmr_unregister_suspend_resume_callback(void)
+{
+	suspend_resume_callback = NULL;
+	suspend_resume_cb_data = NULL;
+}
+EXPORT_SYMBOL_GPL(acpi_pmtmr_unregister_suspend_resume_callback);
+
+static void acpi_pm_suspend(struct clocksource *cs)
+{
+	if (suspend_resume_callback)
+		suspend_resume_callback(suspend_resume_cb_data, true);
+}
+
+static void acpi_pm_resume(struct clocksource *cs)
+{
+	if (suspend_resume_callback)
+		suspend_resume_callback(suspend_resume_cb_data, false);
+}
+
 static u64 acpi_pm_read(struct clocksource *cs)
 {
 	return (u64)read_pmtmr();
@@ -69,6 +99,8 @@ static struct clocksource clocksource_acpi_pm = {
 	.read		= acpi_pm_read,
 	.mask		= (u64)ACPI_PM_MASK,
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.suspend	= acpi_pm_suspend,
+	.resume		= acpi_pm_resume,
 };
 
 
diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h
index 50d88bf..0ded922 100644
--- a/include/linux/acpi_pmtmr.h
+++ b/include/linux/acpi_pmtmr.h
@@ -26,6 +26,19 @@ static inline u32 acpi_pm_read_early(void)
 	return acpi_pm_read_verified() & ACPI_PM_MASK;
 }
 
+/**
+ * Register callback for suspend and resume event
+ *
+ * @cb Callback triggered on suspend and resume
+ * @data Data passed with the callback
+ */
+void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data);
+
+/**
+ * Remove registered callback for suspend and resume event
+ */
+void acpi_pmtmr_unregister_suspend_resume_callback(void);
+
 #else
 
 static inline u32 acpi_pm_read_early(void)

[PATCH v4 2/2] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Marek Maslanka 1 year, 4 months ago

Allow to disable ACPI PM Timer on suspend and enable on resume. A
disabled timer helps optimise power consumption when the system is
suspended. On resume the timer is only reactivated if it was activated
prior to suspend, so unless the ACPI PM timer is enabled in the BIOS,
this won't change anything.

The ACPI PM timer is used by Intel's iTCO/wdat_wdt watchdog to drive the
watchdog, so it doesn't need to run during suspend.

Signed-off-by: Marek Maslanka <mmaslanka@google.com>

---
Changes in v4:
- Enable/disable ACPI PM Timer with the clocksource resume/suspend
  process instead of during pmc_core resume/suspend. Use added callback
  in acpi_pm to do this.
- Do not rely on current set clocksource to check if ACPI PM Timer can
  be disabled.
- Link to v3: https://lore.kernel.org/lkml/20240730120546.1042515-1-mmaslanka@google.com/
---
---
 drivers/platform/x86/intel/pmc/adl.c  |  2 ++
 drivers/platform/x86/intel/pmc/cnp.c  |  2 ++
 drivers/platform/x86/intel/pmc/core.c | 49 +++++++++++++++++++++++++++
 drivers/platform/x86/intel/pmc/core.h |  8 +++++
 drivers/platform/x86/intel/pmc/icl.c  |  2 ++
 drivers/platform/x86/intel/pmc/mtl.c  |  2 ++
 drivers/platform/x86/intel/pmc/spt.c  |  2 ++
 drivers/platform/x86/intel/pmc/tgl.c  |  2 ++
 8 files changed, 69 insertions(+)

diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
index e7878558fd909..9d9c07f44ff61 100644
--- a/drivers/platform/x86/intel/pmc/adl.c
+++ b/drivers/platform/x86/intel/pmc/adl.c
@@ -295,6 +295,8 @@ const struct pmc_reg_map adl_reg_map = {
 	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = ADL_NUM_IP_IGN_ALLOWED,
 	.lpm_num_modes = ADL_LPM_NUM_MODES,
 	.lpm_num_maps = ADL_LPM_NUM_MAPS,
diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
index dd72974bf71e2..513c02670c5aa 100644
--- a/drivers/platform/x86/intel/pmc/cnp.c
+++ b/drivers/platform/x86/intel/pmc/cnp.c
@@ -200,6 +200,8 @@ const struct pmc_reg_map cnp_reg_map = {
 	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = CNP_NUM_IP_IGN_ALLOWED,
 	.etr3_offset = ETR3_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 10c96c1a850af..f6a29530347bb 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -29,6 +29,7 @@
 
 #include "core.h"
 #include "../pmt/telemetry.h"
+#include "../../../../clocksource/acpi_pm.h"
 
 /* Maximum number of modes supported by platfoms that has low power mode capability */
 const char *pmc_lpm_modes[] = {
@@ -1171,6 +1172,42 @@ static bool pmc_core_is_pson_residency_enabled(struct pmc_dev *pmcdev)
 	return val == 1;
 }
 
+/**
+ * Enable or disable ACPI PM Timer
+ *
+ * This function is intended to be a callback for ACPI PM suspend/resume event.
+ * The ACPI PM Timer is enabled on resume only if it was enabled during suspend.
+ */
+static void pmc_core_acpi_pm_timer_suspend_resume(void *data, bool suspend)
+{
+	struct pmc_dev *pmcdev = data;
+	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
+	const struct pmc_reg_map *map = pmc->map;
+	bool enabled;
+	u32 reg;
+
+	if (!map->acpi_pm_tmr_ctl_offset)
+		return;
+
+	mutex_lock(&pmcdev->lock);
+
+	if (!suspend && !pmcdev->enable_acpi_pm_timer_on_resume) {
+		mutex_unlock(&pmcdev->lock);
+		return;
+	}
+
+	reg = pmc_core_reg_read(pmc, map->acpi_pm_tmr_ctl_offset);
+	enabled = !(reg & map->acpi_pm_tmr_disable_bit);
+	if (suspend)
+		reg |= map->acpi_pm_tmr_disable_bit;
+	else
+		reg &= ~map->acpi_pm_tmr_disable_bit;
+	pmc_core_reg_write(pmc, map->acpi_pm_tmr_ctl_offset, reg);
+
+	pmcdev->enable_acpi_pm_timer_on_resume = suspend && enabled;
+
+	mutex_unlock(&pmcdev->lock);
+}
 
 static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
 {
@@ -1362,6 +1399,7 @@ static int pmc_core_probe(struct platform_device *pdev)
 	struct pmc_dev *pmcdev;
 	const struct x86_cpu_id *cpu_id;
 	int (*core_init)(struct pmc_dev *pmcdev);
+	const struct pmc_reg_map *map;
 	struct pmc *primary_pmc;
 	int ret;
 
@@ -1420,6 +1458,11 @@ static int pmc_core_probe(struct platform_device *pdev)
 	pm_report_max_hw_sleep(FIELD_MAX(SLP_S0_RES_COUNTER_MASK) *
 			       pmc_core_adjust_slp_s0_step(primary_pmc, 1));
 
+	map = primary_pmc->map;
+	if (map->acpi_pm_tmr_ctl_offset)
+		acpi_pm_register_suspend_resume_callback(pmc_core_acpi_pm_timer_suspend_resume,
+							 pmcdev);
+
 	device_initialized = true;
 	dev_info(&pdev->dev, " initialized\n");
 
@@ -1429,6 +1472,12 @@ static int pmc_core_probe(struct platform_device *pdev)
 static void pmc_core_remove(struct platform_device *pdev)
 {
 	struct pmc_dev *pmcdev = platform_get_drvdata(pdev);
+	const struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
+	const struct pmc_reg_map *map = pmc->map;
+
+	if (map->acpi_pm_tmr_ctl_offset)
+		acpi_pm_register_suspend_resume_callback(NULL, NULL);
+
 	pmc_core_dbgfs_unregister(pmcdev);
 	pmc_core_clean_structure(pdev);
 }
diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
index 83504c49a0e31..fe1a94f693b63 100644
--- a/drivers/platform/x86/intel/pmc/core.h
+++ b/drivers/platform/x86/intel/pmc/core.h
@@ -67,6 +67,8 @@ struct telem_endpoint;
 #define SPT_PMC_LTR_SCC				0x3A0
 #define SPT_PMC_LTR_ISH				0x3A4
 
+#define SPT_PMC_ACPI_PM_TMR_CTL_OFFSET		0x18FC
+
 /* Sunrise Point: PGD PFET Enable Ack Status Registers */
 enum ppfear_regs {
 	SPT_PMC_XRAM_PPFEAR0A = 0x590,
@@ -147,6 +149,8 @@ enum ppfear_regs {
 #define SPT_PMC_VRIC1_SLPS0LVEN			BIT(13)
 #define SPT_PMC_VRIC1_XTALSDQDIS		BIT(22)
 
+#define SPT_PMC_BIT_ACPI_PM_TMR_DISABLE		BIT(1)
+
 /* Cannonlake Power Management Controller register offsets */
 #define CNP_PMC_SLPS0_DBG_OFFSET		0x10B4
 #define CNP_PMC_PM_CFG_OFFSET			0x1818
@@ -344,6 +348,8 @@ struct pmc_reg_map {
 	const u8  *lpm_reg_index;
 	const u32 pson_residency_offset;
 	const u32 pson_residency_counter_step;
+	const u32 acpi_pm_tmr_ctl_offset;
+	const u32 acpi_pm_tmr_disable_bit;
 };
 
 /**
@@ -417,6 +423,8 @@ struct pmc_dev {
 	u32 die_c6_offset;
 	struct telem_endpoint *punit_ep;
 	struct pmc_info *regmap_list;
+
+	bool enable_acpi_pm_timer_on_resume;
 };
 
 enum pmc_index {
diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c
index 71b0fd6cb7d84..cbbd440544688 100644
--- a/drivers/platform/x86/intel/pmc/icl.c
+++ b/drivers/platform/x86/intel/pmc/icl.c
@@ -46,6 +46,8 @@ const struct pmc_reg_map icl_reg_map = {
 	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = ICL_NUM_IP_IGN_ALLOWED,
 	.etr3_offset = ETR3_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
index c7d15d864039d..91f2fa728f5c8 100644
--- a/drivers/platform/x86/intel/pmc/mtl.c
+++ b/drivers/platform/x86/intel/pmc/mtl.c
@@ -462,6 +462,8 @@ const struct pmc_reg_map mtl_socm_reg_map = {
 	.ppfear_buckets = MTL_SOCM_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.lpm_num_maps = ADL_LPM_NUM_MAPS,
 	.ltr_ignore_max = MTL_SOCM_NUM_IP_IGN_ALLOWED,
 	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c
index ab993a69e33ee..2cd2b3c68e468 100644
--- a/drivers/platform/x86/intel/pmc/spt.c
+++ b/drivers/platform/x86/intel/pmc/spt.c
@@ -130,6 +130,8 @@ const struct pmc_reg_map spt_reg_map = {
 	.ppfear_buckets = SPT_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = SPT_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = SPT_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = SPT_NUM_IP_IGN_ALLOWED,
 	.pm_vric1_offset = SPT_PMC_VRIC1_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
index e0580de180773..371b4e30f1426 100644
--- a/drivers/platform/x86/intel/pmc/tgl.c
+++ b/drivers/platform/x86/intel/pmc/tgl.c
@@ -197,6 +197,8 @@ const struct pmc_reg_map tgl_reg_map = {
 	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = TGL_NUM_IP_IGN_ALLOWED,
 	.lpm_num_maps = TGL_LPM_NUM_MAPS,
 	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
-- 
2.46.0.76.ge559c4bf1a-goog

Re: [PATCH v4 2/2] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Thomas Gleixner 1 year, 4 months ago

On Fri, Aug 09 2024 at 13:13, Marek Maslanka wrote:
> +#include "../../../../clocksource/acpi_pm.h"

No. 

  include/linux/acpi_pmtmr.h

is the right place for this.

[PATCH v5 2/2] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Marek Maslanka 1 year, 4 months ago

Allow to disable ACPI PM Timer on suspend and enable on resume. A
disabled timer helps optimise power consumption when the system is
suspended. On resume the timer is only reactivated if it was activated
prior to suspend, so unless the ACPI PM timer is enabled in the BIOS,
this won't change anything.

The ACPI PM timer is used by Intel's iTCO/wdat_wdt watchdog to drive the
watchdog, so it doesn't need to run during suspend.

Signed-off-by: Marek Maslanka <mmaslanka@google.com>

---
Changes in v5:
- Use renamed acpi_pmtmr_register_suspend_resume_callback instead of
  acpi_pm_register_suspend_resume_callback
- Link to v4: https://lore.kernel.org/lkml/20240809131343.1173369-2-mmaslanka@google.com/
---
---
 drivers/platform/x86/intel/pmc/adl.c  |  2 ++
 drivers/platform/x86/intel/pmc/cnp.c  |  2 ++
 drivers/platform/x86/intel/pmc/core.c | 49 +++++++++++++++++++++++++++
 drivers/platform/x86/intel/pmc/core.h |  8 +++++
 drivers/platform/x86/intel/pmc/icl.c  |  2 ++
 drivers/platform/x86/intel/pmc/mtl.c  |  2 ++
 drivers/platform/x86/intel/pmc/spt.c  |  2 ++
 drivers/platform/x86/intel/pmc/tgl.c  |  2 ++
 8 files changed, 69 insertions(+)

diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
index e7878558fd909..9d9c07f44ff61 100644
--- a/drivers/platform/x86/intel/pmc/adl.c
+++ b/drivers/platform/x86/intel/pmc/adl.c
@@ -295,6 +295,8 @@ const struct pmc_reg_map adl_reg_map = {
 	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = ADL_NUM_IP_IGN_ALLOWED,
 	.lpm_num_modes = ADL_LPM_NUM_MODES,
 	.lpm_num_maps = ADL_LPM_NUM_MAPS,
diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
index dd72974bf71e2..513c02670c5aa 100644
--- a/drivers/platform/x86/intel/pmc/cnp.c
+++ b/drivers/platform/x86/intel/pmc/cnp.c
@@ -200,6 +200,8 @@ const struct pmc_reg_map cnp_reg_map = {
 	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = CNP_NUM_IP_IGN_ALLOWED,
 	.etr3_offset = ETR3_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 10c96c1a850af..d65e3e77ec2ca 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -11,6 +11,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/acpi_pmtmr.h>
 #include <linux/bitfield.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
@@ -1171,6 +1172,42 @@ static bool pmc_core_is_pson_residency_enabled(struct pmc_dev *pmcdev)
 	return val == 1;
 }
 
+/**
+ * Enable or disable ACPI PM Timer
+ *
+ * This function is intended to be a callback for ACPI PM suspend/resume event.
+ * The ACPI PM Timer is enabled on resume only if it was enabled during suspend.
+ */
+static void pmc_core_acpi_pm_timer_suspend_resume(void *data, bool suspend)
+{
+	struct pmc_dev *pmcdev = data;
+	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
+	const struct pmc_reg_map *map = pmc->map;
+	bool enabled;
+	u32 reg;
+
+	if (!map->acpi_pm_tmr_ctl_offset)
+		return;
+
+	mutex_lock(&pmcdev->lock);
+
+	if (!suspend && !pmcdev->enable_acpi_pm_timer_on_resume) {
+		mutex_unlock(&pmcdev->lock);
+		return;
+	}
+
+	reg = pmc_core_reg_read(pmc, map->acpi_pm_tmr_ctl_offset);
+	enabled = !(reg & map->acpi_pm_tmr_disable_bit);
+	if (suspend)
+		reg |= map->acpi_pm_tmr_disable_bit;
+	else
+		reg &= ~map->acpi_pm_tmr_disable_bit;
+	pmc_core_reg_write(pmc, map->acpi_pm_tmr_ctl_offset, reg);
+
+	pmcdev->enable_acpi_pm_timer_on_resume = suspend && enabled;
+
+	mutex_unlock(&pmcdev->lock);
+}
 
 static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
 {
@@ -1362,6 +1399,7 @@ static int pmc_core_probe(struct platform_device *pdev)
 	struct pmc_dev *pmcdev;
 	const struct x86_cpu_id *cpu_id;
 	int (*core_init)(struct pmc_dev *pmcdev);
+	const struct pmc_reg_map *map;
 	struct pmc *primary_pmc;
 	int ret;
 
@@ -1420,6 +1458,11 @@ static int pmc_core_probe(struct platform_device *pdev)
 	pm_report_max_hw_sleep(FIELD_MAX(SLP_S0_RES_COUNTER_MASK) *
 			       pmc_core_adjust_slp_s0_step(primary_pmc, 1));
 
+	map = primary_pmc->map;
+	if (map->acpi_pm_tmr_ctl_offset)
+		acpi_pmtmr_register_suspend_resume_callback(pmc_core_acpi_pm_timer_suspend_resume,
+							 pmcdev);
+
 	device_initialized = true;
 	dev_info(&pdev->dev, " initialized\n");
 
@@ -1429,6 +1472,12 @@ static int pmc_core_probe(struct platform_device *pdev)
 static void pmc_core_remove(struct platform_device *pdev)
 {
 	struct pmc_dev *pmcdev = platform_get_drvdata(pdev);
+	const struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
+	const struct pmc_reg_map *map = pmc->map;
+
+	if (map->acpi_pm_tmr_ctl_offset)
+		acpi_pmtmr_register_suspend_resume_callback(NULL, NULL);
+
 	pmc_core_dbgfs_unregister(pmcdev);
 	pmc_core_clean_structure(pdev);
 }
diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
index 83504c49a0e31..fe1a94f693b63 100644
--- a/drivers/platform/x86/intel/pmc/core.h
+++ b/drivers/platform/x86/intel/pmc/core.h
@@ -67,6 +67,8 @@ struct telem_endpoint;
 #define SPT_PMC_LTR_SCC				0x3A0
 #define SPT_PMC_LTR_ISH				0x3A4
 
+#define SPT_PMC_ACPI_PM_TMR_CTL_OFFSET		0x18FC
+
 /* Sunrise Point: PGD PFET Enable Ack Status Registers */
 enum ppfear_regs {
 	SPT_PMC_XRAM_PPFEAR0A = 0x590,
@@ -147,6 +149,8 @@ enum ppfear_regs {
 #define SPT_PMC_VRIC1_SLPS0LVEN			BIT(13)
 #define SPT_PMC_VRIC1_XTALSDQDIS		BIT(22)
 
+#define SPT_PMC_BIT_ACPI_PM_TMR_DISABLE		BIT(1)
+
 /* Cannonlake Power Management Controller register offsets */
 #define CNP_PMC_SLPS0_DBG_OFFSET		0x10B4
 #define CNP_PMC_PM_CFG_OFFSET			0x1818
@@ -344,6 +348,8 @@ struct pmc_reg_map {
 	const u8  *lpm_reg_index;
 	const u32 pson_residency_offset;
 	const u32 pson_residency_counter_step;
+	const u32 acpi_pm_tmr_ctl_offset;
+	const u32 acpi_pm_tmr_disable_bit;
 };
 
 /**
@@ -417,6 +423,8 @@ struct pmc_dev {
 	u32 die_c6_offset;
 	struct telem_endpoint *punit_ep;
 	struct pmc_info *regmap_list;
+
+	bool enable_acpi_pm_timer_on_resume;
 };
 
 enum pmc_index {
diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c
index 71b0fd6cb7d84..cbbd440544688 100644
--- a/drivers/platform/x86/intel/pmc/icl.c
+++ b/drivers/platform/x86/intel/pmc/icl.c
@@ -46,6 +46,8 @@ const struct pmc_reg_map icl_reg_map = {
 	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = ICL_NUM_IP_IGN_ALLOWED,
 	.etr3_offset = ETR3_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
index c7d15d864039d..91f2fa728f5c8 100644
--- a/drivers/platform/x86/intel/pmc/mtl.c
+++ b/drivers/platform/x86/intel/pmc/mtl.c
@@ -462,6 +462,8 @@ const struct pmc_reg_map mtl_socm_reg_map = {
 	.ppfear_buckets = MTL_SOCM_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.lpm_num_maps = ADL_LPM_NUM_MAPS,
 	.ltr_ignore_max = MTL_SOCM_NUM_IP_IGN_ALLOWED,
 	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c
index ab993a69e33ee..2cd2b3c68e468 100644
--- a/drivers/platform/x86/intel/pmc/spt.c
+++ b/drivers/platform/x86/intel/pmc/spt.c
@@ -130,6 +130,8 @@ const struct pmc_reg_map spt_reg_map = {
 	.ppfear_buckets = SPT_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = SPT_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = SPT_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = SPT_NUM_IP_IGN_ALLOWED,
 	.pm_vric1_offset = SPT_PMC_VRIC1_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
index e0580de180773..371b4e30f1426 100644
--- a/drivers/platform/x86/intel/pmc/tgl.c
+++ b/drivers/platform/x86/intel/pmc/tgl.c
@@ -197,6 +197,8 @@ const struct pmc_reg_map tgl_reg_map = {
 	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = TGL_NUM_IP_IGN_ALLOWED,
 	.lpm_num_maps = TGL_LPM_NUM_MAPS,
 	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
-- 
2.46.0.76.ge559c4bf1a-goog

Re: [PATCH v5 2/2] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Ilpo Järvinen 1 year, 4 months ago

On Mon, 12 Aug 2024, Marek Maslanka wrote:

> Allow to disable ACPI PM Timer on suspend and enable on resume. A
> disabled timer helps optimise power consumption when the system is
> suspended. On resume the timer is only reactivated if it was activated
> prior to suspend, so unless the ACPI PM timer is enabled in the BIOS,
> this won't change anything.
> 
> The ACPI PM timer is used by Intel's iTCO/wdat_wdt watchdog to drive the
> watchdog, so it doesn't need to run during suspend.
> 
> Signed-off-by: Marek Maslanka <mmaslanka@google.com>
> 
> ---
> Changes in v5:
> - Use renamed acpi_pmtmr_register_suspend_resume_callback instead of
>   acpi_pm_register_suspend_resume_callback
> - Link to v4: https://lore.kernel.org/lkml/20240809131343.1173369-2-mmaslanka@google.com/
> ---
> ---
>  drivers/platform/x86/intel/pmc/adl.c  |  2 ++
>  drivers/platform/x86/intel/pmc/cnp.c  |  2 ++
>  drivers/platform/x86/intel/pmc/core.c | 49 +++++++++++++++++++++++++++
>  drivers/platform/x86/intel/pmc/core.h |  8 +++++
>  drivers/platform/x86/intel/pmc/icl.c  |  2 ++
>  drivers/platform/x86/intel/pmc/mtl.c  |  2 ++
>  drivers/platform/x86/intel/pmc/spt.c  |  2 ++
>  drivers/platform/x86/intel/pmc/tgl.c  |  2 ++
>  8 files changed, 69 insertions(+)
> 
> diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
> index e7878558fd909..9d9c07f44ff61 100644
> --- a/drivers/platform/x86/intel/pmc/adl.c
> +++ b/drivers/platform/x86/intel/pmc/adl.c
> @@ -295,6 +295,8 @@ const struct pmc_reg_map adl_reg_map = {
>  	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = ADL_NUM_IP_IGN_ALLOWED,
>  	.lpm_num_modes = ADL_LPM_NUM_MODES,
>  	.lpm_num_maps = ADL_LPM_NUM_MAPS,
> diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
> index dd72974bf71e2..513c02670c5aa 100644
> --- a/drivers/platform/x86/intel/pmc/cnp.c
> +++ b/drivers/platform/x86/intel/pmc/cnp.c
> @@ -200,6 +200,8 @@ const struct pmc_reg_map cnp_reg_map = {
>  	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = CNP_NUM_IP_IGN_ALLOWED,
>  	.etr3_offset = ETR3_OFFSET,
>  };
> diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
> index 10c96c1a850af..d65e3e77ec2ca 100644
> --- a/drivers/platform/x86/intel/pmc/core.c
> +++ b/drivers/platform/x86/intel/pmc/core.c
> @@ -11,6 +11,7 @@
>  
>  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>  
> +#include <linux/acpi_pmtmr.h>
>  #include <linux/bitfield.h>
>  #include <linux/debugfs.h>
>  #include <linux/delay.h>
> @@ -1171,6 +1172,42 @@ static bool pmc_core_is_pson_residency_enabled(struct pmc_dev *pmcdev)
>  	return val == 1;
>  }
>  
> +/**
> + * Enable or disable ACPI PM Timer
> + *
> + * This function is intended to be a callback for ACPI PM suspend/resume event.
> + * The ACPI PM Timer is enabled on resume only if it was enabled during suspend.
> + */
> +static void pmc_core_acpi_pm_timer_suspend_resume(void *data, bool suspend)
> +{
> +	struct pmc_dev *pmcdev = data;
> +	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
> +	const struct pmc_reg_map *map = pmc->map;
> +	bool enabled;
> +	u32 reg;
> +
> +	if (!map->acpi_pm_tmr_ctl_offset)
> +		return;
> +
> +	mutex_lock(&pmcdev->lock);
> +
> +	if (!suspend && !pmcdev->enable_acpi_pm_timer_on_resume) {
> +		mutex_unlock(&pmcdev->lock);

Use guard() in this function so you don't need to manually unlock.

-- 
 i.


> +		return;
> +	}
> +
> +	reg = pmc_core_reg_read(pmc, map->acpi_pm_tmr_ctl_offset);
> +	enabled = !(reg & map->acpi_pm_tmr_disable_bit);
> +	if (suspend)
> +		reg |= map->acpi_pm_tmr_disable_bit;
> +	else
> +		reg &= ~map->acpi_pm_tmr_disable_bit;
> +	pmc_core_reg_write(pmc, map->acpi_pm_tmr_ctl_offset, reg);
> +
> +	pmcdev->enable_acpi_pm_timer_on_resume = suspend && enabled;
> +
> +	mutex_unlock(&pmcdev->lock);
> +}

[PATCH v6 2/2] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Marek Maslanka 1 year, 4 months ago

Allow to disable ACPI PM Timer on suspend and enable on resume. A
disabled timer helps optimise power consumption when the system is
suspended. On resume the timer is only reactivated if it was activated
prior to suspend, so unless the ACPI PM timer is enabled in the BIOS,
this won't change anything.

The ACPI PM timer is used by Intel's iTCO/wdat_wdt watchdog to drive the
watchdog, so it doesn't need to run during suspend.

Signed-off-by: Marek Maslanka <mmaslanka@google.com>

---
Changes in v6:
- Use guard() to manage the mutex instead of mutex_lock/mutex_unlock
- Use newly added acpi_pmtmr_unregister_suspend_resume_callback to remove callback
- Link to v5: https://lore.kernel.org/lkml/20240812044028.3439329-1-mmaslanka@google.com/
---
---
 drivers/platform/x86/intel/pmc/adl.c  |  2 ++
 drivers/platform/x86/intel/pmc/cnp.c  |  2 ++
 drivers/platform/x86/intel/pmc/core.c | 45 +++++++++++++++++++++++++++
 drivers/platform/x86/intel/pmc/core.h |  8 +++++
 drivers/platform/x86/intel/pmc/icl.c  |  2 ++
 drivers/platform/x86/intel/pmc/mtl.c  |  2 ++
 drivers/platform/x86/intel/pmc/spt.c  |  2 ++
 drivers/platform/x86/intel/pmc/tgl.c  |  2 ++
 8 files changed, 65 insertions(+)

diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
index e7878558fd909..9d9c07f44ff61 100644
--- a/drivers/platform/x86/intel/pmc/adl.c
+++ b/drivers/platform/x86/intel/pmc/adl.c
@@ -295,6 +295,8 @@ const struct pmc_reg_map adl_reg_map = {
 	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = ADL_NUM_IP_IGN_ALLOWED,
 	.lpm_num_modes = ADL_LPM_NUM_MODES,
 	.lpm_num_maps = ADL_LPM_NUM_MAPS,
diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
index dd72974bf71e2..513c02670c5aa 100644
--- a/drivers/platform/x86/intel/pmc/cnp.c
+++ b/drivers/platform/x86/intel/pmc/cnp.c
@@ -200,6 +200,8 @@ const struct pmc_reg_map cnp_reg_map = {
 	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = CNP_NUM_IP_IGN_ALLOWED,
 	.etr3_offset = ETR3_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 10c96c1a850af..d8fa9bed4cd3c 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -11,6 +11,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/acpi_pmtmr.h>
 #include <linux/bitfield.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
@@ -1171,6 +1172,38 @@ static bool pmc_core_is_pson_residency_enabled(struct pmc_dev *pmcdev)
 	return val == 1;
 }
 
+/**
+ * Enable or disable ACPI PM Timer
+ *
+ * This function is intended to be a callback for ACPI PM suspend/resume event.
+ * The ACPI PM Timer is enabled on resume only if it was enabled during suspend.
+ */
+static void pmc_core_acpi_pm_timer_suspend_resume(void *data, bool suspend)
+{
+	struct pmc_dev *pmcdev = data;
+	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
+	const struct pmc_reg_map *map = pmc->map;
+	bool enabled;
+	u32 reg;
+
+	if (!map->acpi_pm_tmr_ctl_offset)
+		return;
+
+	guard(mutex)(&pmcdev->lock);
+
+	if (!suspend && !pmcdev->enable_acpi_pm_timer_on_resume)
+		return;
+
+	reg = pmc_core_reg_read(pmc, map->acpi_pm_tmr_ctl_offset);
+	enabled = !(reg & map->acpi_pm_tmr_disable_bit);
+	if (suspend)
+		reg |= map->acpi_pm_tmr_disable_bit;
+	else
+		reg &= ~map->acpi_pm_tmr_disable_bit;
+	pmc_core_reg_write(pmc, map->acpi_pm_tmr_ctl_offset, reg);
+
+	pmcdev->enable_acpi_pm_timer_on_resume = suspend && enabled;
+}
 
 static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
 {
@@ -1362,6 +1395,7 @@ static int pmc_core_probe(struct platform_device *pdev)
 	struct pmc_dev *pmcdev;
 	const struct x86_cpu_id *cpu_id;
 	int (*core_init)(struct pmc_dev *pmcdev);
+	const struct pmc_reg_map *map;
 	struct pmc *primary_pmc;
 	int ret;
 
@@ -1420,6 +1454,11 @@ static int pmc_core_probe(struct platform_device *pdev)
 	pm_report_max_hw_sleep(FIELD_MAX(SLP_S0_RES_COUNTER_MASK) *
 			       pmc_core_adjust_slp_s0_step(primary_pmc, 1));
 
+	map = primary_pmc->map;
+	if (map->acpi_pm_tmr_ctl_offset)
+		acpi_pmtmr_register_suspend_resume_callback(pmc_core_acpi_pm_timer_suspend_resume,
+							 pmcdev);
+
 	device_initialized = true;
 	dev_info(&pdev->dev, " initialized\n");
 
@@ -1429,6 +1468,12 @@ static int pmc_core_probe(struct platform_device *pdev)
 static void pmc_core_remove(struct platform_device *pdev)
 {
 	struct pmc_dev *pmcdev = platform_get_drvdata(pdev);
+	const struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
+	const struct pmc_reg_map *map = pmc->map;
+
+	if (map->acpi_pm_tmr_ctl_offset)
+		acpi_pmtmr_unregister_suspend_resume_callback();
+
 	pmc_core_dbgfs_unregister(pmcdev);
 	pmc_core_clean_structure(pdev);
 }
diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
index 83504c49a0e31..fe1a94f693b63 100644
--- a/drivers/platform/x86/intel/pmc/core.h
+++ b/drivers/platform/x86/intel/pmc/core.h
@@ -67,6 +67,8 @@ struct telem_endpoint;
 #define SPT_PMC_LTR_SCC				0x3A0
 #define SPT_PMC_LTR_ISH				0x3A4
 
+#define SPT_PMC_ACPI_PM_TMR_CTL_OFFSET		0x18FC
+
 /* Sunrise Point: PGD PFET Enable Ack Status Registers */
 enum ppfear_regs {
 	SPT_PMC_XRAM_PPFEAR0A = 0x590,
@@ -147,6 +149,8 @@ enum ppfear_regs {
 #define SPT_PMC_VRIC1_SLPS0LVEN			BIT(13)
 #define SPT_PMC_VRIC1_XTALSDQDIS		BIT(22)
 
+#define SPT_PMC_BIT_ACPI_PM_TMR_DISABLE		BIT(1)
+
 /* Cannonlake Power Management Controller register offsets */
 #define CNP_PMC_SLPS0_DBG_OFFSET		0x10B4
 #define CNP_PMC_PM_CFG_OFFSET			0x1818
@@ -344,6 +348,8 @@ struct pmc_reg_map {
 	const u8  *lpm_reg_index;
 	const u32 pson_residency_offset;
 	const u32 pson_residency_counter_step;
+	const u32 acpi_pm_tmr_ctl_offset;
+	const u32 acpi_pm_tmr_disable_bit;
 };
 
 /**
@@ -417,6 +423,8 @@ struct pmc_dev {
 	u32 die_c6_offset;
 	struct telem_endpoint *punit_ep;
 	struct pmc_info *regmap_list;
+
+	bool enable_acpi_pm_timer_on_resume;
 };
 
 enum pmc_index {
diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c
index 71b0fd6cb7d84..cbbd440544688 100644
--- a/drivers/platform/x86/intel/pmc/icl.c
+++ b/drivers/platform/x86/intel/pmc/icl.c
@@ -46,6 +46,8 @@ const struct pmc_reg_map icl_reg_map = {
 	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = ICL_NUM_IP_IGN_ALLOWED,
 	.etr3_offset = ETR3_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
index c7d15d864039d..91f2fa728f5c8 100644
--- a/drivers/platform/x86/intel/pmc/mtl.c
+++ b/drivers/platform/x86/intel/pmc/mtl.c
@@ -462,6 +462,8 @@ const struct pmc_reg_map mtl_socm_reg_map = {
 	.ppfear_buckets = MTL_SOCM_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.lpm_num_maps = ADL_LPM_NUM_MAPS,
 	.ltr_ignore_max = MTL_SOCM_NUM_IP_IGN_ALLOWED,
 	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c
index ab993a69e33ee..2cd2b3c68e468 100644
--- a/drivers/platform/x86/intel/pmc/spt.c
+++ b/drivers/platform/x86/intel/pmc/spt.c
@@ -130,6 +130,8 @@ const struct pmc_reg_map spt_reg_map = {
 	.ppfear_buckets = SPT_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = SPT_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = SPT_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = SPT_NUM_IP_IGN_ALLOWED,
 	.pm_vric1_offset = SPT_PMC_VRIC1_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
index e0580de180773..371b4e30f1426 100644
--- a/drivers/platform/x86/intel/pmc/tgl.c
+++ b/drivers/platform/x86/intel/pmc/tgl.c
@@ -197,6 +197,8 @@ const struct pmc_reg_map tgl_reg_map = {
 	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = TGL_NUM_IP_IGN_ALLOWED,
 	.lpm_num_maps = TGL_LPM_NUM_MAPS,
 	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
-- 
2.46.0.76.ge559c4bf1a-goog

Re: [PATCH v6 2/2] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Hans de Goede 1 year, 4 months ago

Hi,

On 8/12/24 8:42 PM, Marek Maslanka wrote:
> Allow to disable ACPI PM Timer on suspend and enable on resume. A
> disabled timer helps optimise power consumption when the system is
> suspended. On resume the timer is only reactivated if it was activated
> prior to suspend, so unless the ACPI PM timer is enabled in the BIOS,
> this won't change anything.
> 
> The ACPI PM timer is used by Intel's iTCO/wdat_wdt watchdog to drive the
> watchdog, so it doesn't need to run during suspend.
> 
> Signed-off-by: Marek Maslanka <mmaslanka@google.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans


> 
> ---
> Changes in v6:
> - Use guard() to manage the mutex instead of mutex_lock/mutex_unlock
> - Use newly added acpi_pmtmr_unregister_suspend_resume_callback to remove callback
> - Link to v5: https://lore.kernel.org/lkml/20240812044028.3439329-1-mmaslanka@google.com/
> ---
> ---
>  drivers/platform/x86/intel/pmc/adl.c  |  2 ++
>  drivers/platform/x86/intel/pmc/cnp.c  |  2 ++
>  drivers/platform/x86/intel/pmc/core.c | 45 +++++++++++++++++++++++++++
>  drivers/platform/x86/intel/pmc/core.h |  8 +++++
>  drivers/platform/x86/intel/pmc/icl.c  |  2 ++
>  drivers/platform/x86/intel/pmc/mtl.c  |  2 ++
>  drivers/platform/x86/intel/pmc/spt.c  |  2 ++
>  drivers/platform/x86/intel/pmc/tgl.c  |  2 ++
>  8 files changed, 65 insertions(+)
> 
> diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
> index e7878558fd909..9d9c07f44ff61 100644
> --- a/drivers/platform/x86/intel/pmc/adl.c
> +++ b/drivers/platform/x86/intel/pmc/adl.c
> @@ -295,6 +295,8 @@ const struct pmc_reg_map adl_reg_map = {
>  	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = ADL_NUM_IP_IGN_ALLOWED,
>  	.lpm_num_modes = ADL_LPM_NUM_MODES,
>  	.lpm_num_maps = ADL_LPM_NUM_MAPS,
> diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
> index dd72974bf71e2..513c02670c5aa 100644
> --- a/drivers/platform/x86/intel/pmc/cnp.c
> +++ b/drivers/platform/x86/intel/pmc/cnp.c
> @@ -200,6 +200,8 @@ const struct pmc_reg_map cnp_reg_map = {
>  	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = CNP_NUM_IP_IGN_ALLOWED,
>  	.etr3_offset = ETR3_OFFSET,
>  };
> diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
> index 10c96c1a850af..d8fa9bed4cd3c 100644
> --- a/drivers/platform/x86/intel/pmc/core.c
> +++ b/drivers/platform/x86/intel/pmc/core.c
> @@ -11,6 +11,7 @@
>  
>  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>  
> +#include <linux/acpi_pmtmr.h>
>  #include <linux/bitfield.h>
>  #include <linux/debugfs.h>
>  #include <linux/delay.h>
> @@ -1171,6 +1172,38 @@ static bool pmc_core_is_pson_residency_enabled(struct pmc_dev *pmcdev)
>  	return val == 1;
>  }
>  
> +/**
> + * Enable or disable ACPI PM Timer
> + *
> + * This function is intended to be a callback for ACPI PM suspend/resume event.
> + * The ACPI PM Timer is enabled on resume only if it was enabled during suspend.
> + */
> +static void pmc_core_acpi_pm_timer_suspend_resume(void *data, bool suspend)
> +{
> +	struct pmc_dev *pmcdev = data;
> +	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
> +	const struct pmc_reg_map *map = pmc->map;
> +	bool enabled;
> +	u32 reg;
> +
> +	if (!map->acpi_pm_tmr_ctl_offset)
> +		return;
> +
> +	guard(mutex)(&pmcdev->lock);
> +
> +	if (!suspend && !pmcdev->enable_acpi_pm_timer_on_resume)
> +		return;
> +
> +	reg = pmc_core_reg_read(pmc, map->acpi_pm_tmr_ctl_offset);
> +	enabled = !(reg & map->acpi_pm_tmr_disable_bit);
> +	if (suspend)
> +		reg |= map->acpi_pm_tmr_disable_bit;
> +	else
> +		reg &= ~map->acpi_pm_tmr_disable_bit;
> +	pmc_core_reg_write(pmc, map->acpi_pm_tmr_ctl_offset, reg);
> +
> +	pmcdev->enable_acpi_pm_timer_on_resume = suspend && enabled;
> +}
>  
>  static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
>  {
> @@ -1362,6 +1395,7 @@ static int pmc_core_probe(struct platform_device *pdev)
>  	struct pmc_dev *pmcdev;
>  	const struct x86_cpu_id *cpu_id;
>  	int (*core_init)(struct pmc_dev *pmcdev);
> +	const struct pmc_reg_map *map;
>  	struct pmc *primary_pmc;
>  	int ret;
>  
> @@ -1420,6 +1454,11 @@ static int pmc_core_probe(struct platform_device *pdev)
>  	pm_report_max_hw_sleep(FIELD_MAX(SLP_S0_RES_COUNTER_MASK) *
>  			       pmc_core_adjust_slp_s0_step(primary_pmc, 1));
>  
> +	map = primary_pmc->map;
> +	if (map->acpi_pm_tmr_ctl_offset)
> +		acpi_pmtmr_register_suspend_resume_callback(pmc_core_acpi_pm_timer_suspend_resume,
> +							 pmcdev);
> +
>  	device_initialized = true;
>  	dev_info(&pdev->dev, " initialized\n");
>  
> @@ -1429,6 +1468,12 @@ static int pmc_core_probe(struct platform_device *pdev)
>  static void pmc_core_remove(struct platform_device *pdev)
>  {
>  	struct pmc_dev *pmcdev = platform_get_drvdata(pdev);
> +	const struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
> +	const struct pmc_reg_map *map = pmc->map;
> +
> +	if (map->acpi_pm_tmr_ctl_offset)
> +		acpi_pmtmr_unregister_suspend_resume_callback();
> +
>  	pmc_core_dbgfs_unregister(pmcdev);
>  	pmc_core_clean_structure(pdev);
>  }
> diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
> index 83504c49a0e31..fe1a94f693b63 100644
> --- a/drivers/platform/x86/intel/pmc/core.h
> +++ b/drivers/platform/x86/intel/pmc/core.h
> @@ -67,6 +67,8 @@ struct telem_endpoint;
>  #define SPT_PMC_LTR_SCC				0x3A0
>  #define SPT_PMC_LTR_ISH				0x3A4
>  
> +#define SPT_PMC_ACPI_PM_TMR_CTL_OFFSET		0x18FC
> +
>  /* Sunrise Point: PGD PFET Enable Ack Status Registers */
>  enum ppfear_regs {
>  	SPT_PMC_XRAM_PPFEAR0A = 0x590,
> @@ -147,6 +149,8 @@ enum ppfear_regs {
>  #define SPT_PMC_VRIC1_SLPS0LVEN			BIT(13)
>  #define SPT_PMC_VRIC1_XTALSDQDIS		BIT(22)
>  
> +#define SPT_PMC_BIT_ACPI_PM_TMR_DISABLE		BIT(1)
> +
>  /* Cannonlake Power Management Controller register offsets */
>  #define CNP_PMC_SLPS0_DBG_OFFSET		0x10B4
>  #define CNP_PMC_PM_CFG_OFFSET			0x1818
> @@ -344,6 +348,8 @@ struct pmc_reg_map {
>  	const u8  *lpm_reg_index;
>  	const u32 pson_residency_offset;
>  	const u32 pson_residency_counter_step;
> +	const u32 acpi_pm_tmr_ctl_offset;
> +	const u32 acpi_pm_tmr_disable_bit;
>  };
>  
>  /**
> @@ -417,6 +423,8 @@ struct pmc_dev {
>  	u32 die_c6_offset;
>  	struct telem_endpoint *punit_ep;
>  	struct pmc_info *regmap_list;
> +
> +	bool enable_acpi_pm_timer_on_resume;
>  };
>  
>  enum pmc_index {
> diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c
> index 71b0fd6cb7d84..cbbd440544688 100644
> --- a/drivers/platform/x86/intel/pmc/icl.c
> +++ b/drivers/platform/x86/intel/pmc/icl.c
> @@ -46,6 +46,8 @@ const struct pmc_reg_map icl_reg_map = {
>  	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = ICL_NUM_IP_IGN_ALLOWED,
>  	.etr3_offset = ETR3_OFFSET,
>  };
> diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
> index c7d15d864039d..91f2fa728f5c8 100644
> --- a/drivers/platform/x86/intel/pmc/mtl.c
> +++ b/drivers/platform/x86/intel/pmc/mtl.c
> @@ -462,6 +462,8 @@ const struct pmc_reg_map mtl_socm_reg_map = {
>  	.ppfear_buckets = MTL_SOCM_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.lpm_num_maps = ADL_LPM_NUM_MAPS,
>  	.ltr_ignore_max = MTL_SOCM_NUM_IP_IGN_ALLOWED,
>  	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
> diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c
> index ab993a69e33ee..2cd2b3c68e468 100644
> --- a/drivers/platform/x86/intel/pmc/spt.c
> +++ b/drivers/platform/x86/intel/pmc/spt.c
> @@ -130,6 +130,8 @@ const struct pmc_reg_map spt_reg_map = {
>  	.ppfear_buckets = SPT_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = SPT_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = SPT_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = SPT_NUM_IP_IGN_ALLOWED,
>  	.pm_vric1_offset = SPT_PMC_VRIC1_OFFSET,
>  };
> diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
> index e0580de180773..371b4e30f1426 100644
> --- a/drivers/platform/x86/intel/pmc/tgl.c
> +++ b/drivers/platform/x86/intel/pmc/tgl.c
> @@ -197,6 +197,8 @@ const struct pmc_reg_map tgl_reg_map = {
>  	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = TGL_NUM_IP_IGN_ALLOWED,
>  	.lpm_num_maps = TGL_LPM_NUM_MAPS,
>  	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,

[tip: timers/core] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by tip-bot2 for Marek Maslanka 1 year, 3 months ago

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     e86c8186d03a6ba018e881ed45f0962ad553e861
Gitweb:        https://git.kernel.org/tip/e86c8186d03a6ba018e881ed45f0962ad553e861
Author:        Marek Maslanka <mmaslanka@google.com>
AuthorDate:    Mon, 12 Aug 2024 18:42:00 
Committer:     Daniel Lezcano <daniel.lezcano@linaro.org>
CommitterDate: Fri, 06 Sep 2024 14:49:20 +02:00

platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Allow to disable ACPI PM Timer on suspend and enable on resume. A
disabled timer helps optimise power consumption when the system is
suspended. On resume the timer is only reactivated if it was activated
prior to suspend, so unless the ACPI PM timer is enabled in the BIOS,
this won't change anything.

The ACPI PM timer is used by Intel's iTCO/wdat_wdt watchdog to drive the
watchdog, so it doesn't need to run during suspend.

Signed-off-by: Marek Maslanka <mmaslanka@google.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240812184208.1080710-1-mmaslanka@google.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/platform/x86/intel/pmc/adl.c  |  2 +-
 drivers/platform/x86/intel/pmc/cnp.c  |  2 +-
 drivers/platform/x86/intel/pmc/core.c | 45 ++++++++++++++++++++++++++-
 drivers/platform/x86/intel/pmc/core.h |  8 +++++-
 drivers/platform/x86/intel/pmc/icl.c  |  2 +-
 drivers/platform/x86/intel/pmc/mtl.c  |  2 +-
 drivers/platform/x86/intel/pmc/spt.c  |  2 +-
 drivers/platform/x86/intel/pmc/tgl.c  |  2 +-
 8 files changed, 65 insertions(+)

diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
index e787855..9d9c07f 100644
--- a/drivers/platform/x86/intel/pmc/adl.c
+++ b/drivers/platform/x86/intel/pmc/adl.c
@@ -295,6 +295,8 @@ const struct pmc_reg_map adl_reg_map = {
 	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = ADL_NUM_IP_IGN_ALLOWED,
 	.lpm_num_modes = ADL_LPM_NUM_MODES,
 	.lpm_num_maps = ADL_LPM_NUM_MAPS,
diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
index dd72974..513c026 100644
--- a/drivers/platform/x86/intel/pmc/cnp.c
+++ b/drivers/platform/x86/intel/pmc/cnp.c
@@ -200,6 +200,8 @@ const struct pmc_reg_map cnp_reg_map = {
 	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = CNP_NUM_IP_IGN_ALLOWED,
 	.etr3_offset = ETR3_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 01ae71c..c91c753 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -11,6 +11,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/acpi_pmtmr.h>
 #include <linux/bitfield.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
@@ -1208,6 +1209,38 @@ static bool pmc_core_is_pson_residency_enabled(struct pmc_dev *pmcdev)
 	return val == 1;
 }
 
+/**
+ * Enable or disable ACPI PM Timer
+ *
+ * This function is intended to be a callback for ACPI PM suspend/resume event.
+ * The ACPI PM Timer is enabled on resume only if it was enabled during suspend.
+ */
+static void pmc_core_acpi_pm_timer_suspend_resume(void *data, bool suspend)
+{
+	struct pmc_dev *pmcdev = data;
+	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
+	const struct pmc_reg_map *map = pmc->map;
+	bool enabled;
+	u32 reg;
+
+	if (!map->acpi_pm_tmr_ctl_offset)
+		return;
+
+	guard(mutex)(&pmcdev->lock);
+
+	if (!suspend && !pmcdev->enable_acpi_pm_timer_on_resume)
+		return;
+
+	reg = pmc_core_reg_read(pmc, map->acpi_pm_tmr_ctl_offset);
+	enabled = !(reg & map->acpi_pm_tmr_disable_bit);
+	if (suspend)
+		reg |= map->acpi_pm_tmr_disable_bit;
+	else
+		reg &= ~map->acpi_pm_tmr_disable_bit;
+	pmc_core_reg_write(pmc, map->acpi_pm_tmr_ctl_offset, reg);
+
+	pmcdev->enable_acpi_pm_timer_on_resume = suspend && enabled;
+}
 
 static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
 {
@@ -1404,6 +1437,7 @@ static int pmc_core_probe(struct platform_device *pdev)
 	struct pmc_dev *pmcdev;
 	const struct x86_cpu_id *cpu_id;
 	int (*core_init)(struct pmc_dev *pmcdev);
+	const struct pmc_reg_map *map;
 	struct pmc *primary_pmc;
 	int ret;
 
@@ -1462,6 +1496,11 @@ static int pmc_core_probe(struct platform_device *pdev)
 	pm_report_max_hw_sleep(FIELD_MAX(SLP_S0_RES_COUNTER_MASK) *
 			       pmc_core_adjust_slp_s0_step(primary_pmc, 1));
 
+	map = primary_pmc->map;
+	if (map->acpi_pm_tmr_ctl_offset)
+		acpi_pmtmr_register_suspend_resume_callback(pmc_core_acpi_pm_timer_suspend_resume,
+							 pmcdev);
+
 	device_initialized = true;
 	dev_info(&pdev->dev, " initialized\n");
 
@@ -1471,6 +1510,12 @@ static int pmc_core_probe(struct platform_device *pdev)
 static void pmc_core_remove(struct platform_device *pdev)
 {
 	struct pmc_dev *pmcdev = platform_get_drvdata(pdev);
+	const struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
+	const struct pmc_reg_map *map = pmc->map;
+
+	if (map->acpi_pm_tmr_ctl_offset)
+		acpi_pmtmr_unregister_suspend_resume_callback();
+
 	pmc_core_dbgfs_unregister(pmcdev);
 	pmc_core_clean_structure(pdev);
 }
diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
index ea04de7..4d37ef7 100644
--- a/drivers/platform/x86/intel/pmc/core.h
+++ b/drivers/platform/x86/intel/pmc/core.h
@@ -68,6 +68,8 @@ struct telem_endpoint;
 #define SPT_PMC_LTR_SCC				0x3A0
 #define SPT_PMC_LTR_ISH				0x3A4
 
+#define SPT_PMC_ACPI_PM_TMR_CTL_OFFSET		0x18FC
+
 /* Sunrise Point: PGD PFET Enable Ack Status Registers */
 enum ppfear_regs {
 	SPT_PMC_XRAM_PPFEAR0A = 0x590,
@@ -148,6 +150,8 @@ enum ppfear_regs {
 #define SPT_PMC_VRIC1_SLPS0LVEN			BIT(13)
 #define SPT_PMC_VRIC1_XTALSDQDIS		BIT(22)
 
+#define SPT_PMC_BIT_ACPI_PM_TMR_DISABLE		BIT(1)
+
 /* Cannonlake Power Management Controller register offsets */
 #define CNP_PMC_SLPS0_DBG_OFFSET		0x10B4
 #define CNP_PMC_PM_CFG_OFFSET			0x1818
@@ -351,6 +355,8 @@ struct pmc_reg_map {
 	const u8  *lpm_reg_index;
 	const u32 pson_residency_offset;
 	const u32 pson_residency_counter_step;
+	const u32 acpi_pm_tmr_ctl_offset;
+	const u32 acpi_pm_tmr_disable_bit;
 };
 
 /**
@@ -424,6 +430,8 @@ struct pmc_dev {
 	u32 die_c6_offset;
 	struct telem_endpoint *punit_ep;
 	struct pmc_info *regmap_list;
+
+	bool enable_acpi_pm_timer_on_resume;
 };
 
 enum pmc_index {
diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c
index 71b0fd6..cbbd440 100644
--- a/drivers/platform/x86/intel/pmc/icl.c
+++ b/drivers/platform/x86/intel/pmc/icl.c
@@ -46,6 +46,8 @@ const struct pmc_reg_map icl_reg_map = {
 	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = ICL_NUM_IP_IGN_ALLOWED,
 	.etr3_offset = ETR3_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
index c7d15d8..91f2fa7 100644
--- a/drivers/platform/x86/intel/pmc/mtl.c
+++ b/drivers/platform/x86/intel/pmc/mtl.c
@@ -462,6 +462,8 @@ const struct pmc_reg_map mtl_socm_reg_map = {
 	.ppfear_buckets = MTL_SOCM_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.lpm_num_maps = ADL_LPM_NUM_MAPS,
 	.ltr_ignore_max = MTL_SOCM_NUM_IP_IGN_ALLOWED,
 	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c
index ab993a6..2cd2b3c 100644
--- a/drivers/platform/x86/intel/pmc/spt.c
+++ b/drivers/platform/x86/intel/pmc/spt.c
@@ -130,6 +130,8 @@ const struct pmc_reg_map spt_reg_map = {
 	.ppfear_buckets = SPT_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = SPT_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = SPT_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = SPT_NUM_IP_IGN_ALLOWED,
 	.pm_vric1_offset = SPT_PMC_VRIC1_OFFSET,
 };
diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
index e0580de..371b4e3 100644
--- a/drivers/platform/x86/intel/pmc/tgl.c
+++ b/drivers/platform/x86/intel/pmc/tgl.c
@@ -197,6 +197,8 @@ const struct pmc_reg_map tgl_reg_map = {
 	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
+	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
+	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
 	.ltr_ignore_max = TGL_NUM_IP_IGN_ALLOWED,
 	.lpm_num_maps = TGL_LPM_NUM_MAPS,
 	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,

Re: [PATCH v3] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Thomas Gleixner 1 year, 4 months ago

On Wed, Jul 31 2024 at 23:41, Marek Maślanka wrote:
> On Wed, Jul 31, 2024 at 6:33 PM Thomas Gleixner <tglx@linutronix.de> wrote:
>> On Wed, Jul 31 2024 at 16:44, Marek Maślanka wrote:
>> > Thanks. I'll try do this in that way. But I need to disable/enable
>> > ACPI PM timer only on suspend/resume, so I'll use suspend/resume
>> > callbacks.
>>
>> Why? What's the point of keeping it running when nothing uses it?
>>
> In case of Intel CPUs the watchdog (iTCO/wdat_wdt) is driven by ACPI PM
> Timer. But it may also be used by others that I don't know about, so I don't
> want to disable it.

Fair enough.

Re: [PATCH v3] platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended

Posted by Ilpo Järvinen 1 year, 4 months ago

On Tue, 30 Jul 2024, Marek Maslanka wrote:

> Allow to disable ACPI PM Timer on suspend and enable on resume. A
> disabled timer helps optimise power consumption when the system is
> suspended. On resume the timer is only reactivated if it was activated
> prior to suspend, so unless the ACPI PM timer is enabled in the BIOS,
> this won't change anything.
> 
> Signed-off-by: Marek Maslanka <mmaslanka@google.com>
> 
> ---
> Changes in v3:
> - Add the clocksource_current_cs_name and clocksource_suspend_cs_name to the clocksource.c
> - Do not disable the ACPI PM timer if it's selected as the clocksource
> - Link to v2: https://lore.kernel.org/lkml/20240703113850.2726539-1-mmaslanka@google.com/
> ---
> ---
>  drivers/platform/x86/intel/pmc/adl.c  |  2 ++
>  drivers/platform/x86/intel/pmc/cnp.c  |  2 ++
>  drivers/platform/x86/intel/pmc/core.c | 47 +++++++++++++++++++++++++++
>  drivers/platform/x86/intel/pmc/core.h |  8 +++++
>  drivers/platform/x86/intel/pmc/icl.c  |  2 ++
>  drivers/platform/x86/intel/pmc/mtl.c  |  2 ++
>  drivers/platform/x86/intel/pmc/spt.c  |  2 ++
>  drivers/platform/x86/intel/pmc/tgl.c  |  2 ++
>  include/linux/clocksource.h           |  2 ++
>  kernel/time/clocksource.c             | 22 +++++++++++++
>  10 files changed, 91 insertions(+)
> 
> diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
> index e7878558fd909..9d9c07f44ff61 100644
> --- a/drivers/platform/x86/intel/pmc/adl.c
> +++ b/drivers/platform/x86/intel/pmc/adl.c
> @@ -295,6 +295,8 @@ const struct pmc_reg_map adl_reg_map = {
>  	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = ADL_NUM_IP_IGN_ALLOWED,
>  	.lpm_num_modes = ADL_LPM_NUM_MODES,
>  	.lpm_num_maps = ADL_LPM_NUM_MAPS,
> diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
> index dd72974bf71e2..513c02670c5aa 100644
> --- a/drivers/platform/x86/intel/pmc/cnp.c
> +++ b/drivers/platform/x86/intel/pmc/cnp.c
> @@ -200,6 +200,8 @@ const struct pmc_reg_map cnp_reg_map = {
>  	.ppfear_buckets = CNP_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = CNP_NUM_IP_IGN_ALLOWED,
>  	.etr3_offset = ETR3_OFFSET,
>  };
> diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
> index 10c96c1a850af..1a435f5ca08c5 100644
> --- a/drivers/platform/x86/intel/pmc/core.c
> +++ b/drivers/platform/x86/intel/pmc/core.c
> @@ -12,6 +12,7 @@
>  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>  
>  #include <linux/bitfield.h>
> +#include <linux/clocksource.h>
>  #include <linux/debugfs.h>
>  #include <linux/delay.h>
>  #include <linux/dmi.h>
> @@ -1171,6 +1172,44 @@ static bool pmc_core_is_pson_residency_enabled(struct pmc_dev *pmcdev)
>  	return val == 1;
>  }
>  
> +/*
> + * Enable or disable APCI PM Timer
> + *
> + * @return: Previous APCI PM Timer enabled state
> + */
> +static bool pmc_core_enable_apci_pm_timer(struct pmc_dev *pmcdev, bool enable)
> +{
> +	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
> +	const struct pmc_reg_map *map = pmc->map;
> +	char cs_name[32];
> +	bool state;
> +	u32 reg;
> +
> +	if (!map->acpi_pm_tmr_ctl_offset)
> +		return false;
> +
> +	clocksource_current_cs_name(cs_name, sizeof(cs_name));
> +	if (strncmp(cs_name, "acpi_pm", sizeof(cs_name)) == 0)

If you want to do a prefix check, there's str_has_prefix() for that.
Otherwise, I don't understand why you need the n variant?

> +		return false;
> +
> +	clocksource_suspend_cs_name(cs_name, sizeof(cs_name));
> +	if (strncmp(cs_name, "acpi_pm", sizeof(cs_name)) == 0)
> +		return false;
> +
> +	mutex_lock(&pmcdev->lock);
> +
> +	reg = pmc_core_reg_read(pmc, map->acpi_pm_tmr_ctl_offset);
> +	state = !(reg & map->acpi_pm_tmr_disable_bit);
> +	if (enable)
> +		reg &= ~map->acpi_pm_tmr_disable_bit;
> +	else
> +		reg |= map->acpi_pm_tmr_disable_bit;
> +	pmc_core_reg_write(pmc, map->acpi_pm_tmr_ctl_offset, reg);
> +
> +	mutex_unlock(&pmcdev->lock);
> +
> +	return state;
> +}
>  
>  static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
>  {
> @@ -1446,6 +1485,10 @@ static __maybe_unused int pmc_core_suspend(struct device *dev)
>  	if (pmcdev->suspend)
>  		pmcdev->suspend(pmcdev);
>  
> +	/* Disable APCI PM Timer */
> +	pmcdev->enable_acpi_pm_timer_on_resume =
> +		pmc_core_enable_apci_pm_timer(pmcdev, false);
> +
>  	/* Check if the syspend will actually use S0ix */
>  	if (pm_suspend_via_firmware())
>  		return 0;
> @@ -1500,6 +1543,10 @@ int pmc_core_resume_common(struct pmc_dev *pmcdev)
>  	int offset = pmc->map->lpm_status_offset;
>  	int i;
>  
> +	/* Enable APCI PM Timer */
> +	if (pmcdev->enable_acpi_pm_timer_on_resume)
> +		pmc_core_enable_apci_pm_timer(pmcdev, true);
> +
>  	/* Check if the syspend used S0ix */
>  	if (pm_suspend_via_firmware())
>  		return 0;
> diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
> index 83504c49a0e31..fe1a94f693b63 100644
> --- a/drivers/platform/x86/intel/pmc/core.h
> +++ b/drivers/platform/x86/intel/pmc/core.h
> @@ -67,6 +67,8 @@ struct telem_endpoint;
>  #define SPT_PMC_LTR_SCC				0x3A0
>  #define SPT_PMC_LTR_ISH				0x3A4
>  
> +#define SPT_PMC_ACPI_PM_TMR_CTL_OFFSET		0x18FC
> +
>  /* Sunrise Point: PGD PFET Enable Ack Status Registers */
>  enum ppfear_regs {
>  	SPT_PMC_XRAM_PPFEAR0A = 0x590,
> @@ -147,6 +149,8 @@ enum ppfear_regs {
>  #define SPT_PMC_VRIC1_SLPS0LVEN			BIT(13)
>  #define SPT_PMC_VRIC1_XTALSDQDIS		BIT(22)
>  
> +#define SPT_PMC_BIT_ACPI_PM_TMR_DISABLE		BIT(1)
> +
>  /* Cannonlake Power Management Controller register offsets */
>  #define CNP_PMC_SLPS0_DBG_OFFSET		0x10B4
>  #define CNP_PMC_PM_CFG_OFFSET			0x1818
> @@ -344,6 +348,8 @@ struct pmc_reg_map {
>  	const u8  *lpm_reg_index;
>  	const u32 pson_residency_offset;
>  	const u32 pson_residency_counter_step;
> +	const u32 acpi_pm_tmr_ctl_offset;
> +	const u32 acpi_pm_tmr_disable_bit;
>  };
>  
>  /**
> @@ -417,6 +423,8 @@ struct pmc_dev {
>  	u32 die_c6_offset;
>  	struct telem_endpoint *punit_ep;
>  	struct pmc_info *regmap_list;
> +
> +	bool enable_acpi_pm_timer_on_resume;
>  };
>  
>  enum pmc_index {
> diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c
> index 71b0fd6cb7d84..cbbd440544688 100644
> --- a/drivers/platform/x86/intel/pmc/icl.c
> +++ b/drivers/platform/x86/intel/pmc/icl.c
> @@ -46,6 +46,8 @@ const struct pmc_reg_map icl_reg_map = {
>  	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = ICL_NUM_IP_IGN_ALLOWED,
>  	.etr3_offset = ETR3_OFFSET,
>  };
> diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
> index c7d15d864039d..91f2fa728f5c8 100644
> --- a/drivers/platform/x86/intel/pmc/mtl.c
> +++ b/drivers/platform/x86/intel/pmc/mtl.c
> @@ -462,6 +462,8 @@ const struct pmc_reg_map mtl_socm_reg_map = {
>  	.ppfear_buckets = MTL_SOCM_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.lpm_num_maps = ADL_LPM_NUM_MAPS,
>  	.ltr_ignore_max = MTL_SOCM_NUM_IP_IGN_ALLOWED,
>  	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
> diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c
> index ab993a69e33ee..2cd2b3c68e468 100644
> --- a/drivers/platform/x86/intel/pmc/spt.c
> +++ b/drivers/platform/x86/intel/pmc/spt.c
> @@ -130,6 +130,8 @@ const struct pmc_reg_map spt_reg_map = {
>  	.ppfear_buckets = SPT_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = SPT_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = SPT_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = SPT_NUM_IP_IGN_ALLOWED,
>  	.pm_vric1_offset = SPT_PMC_VRIC1_OFFSET,
>  };
> diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
> index e0580de180773..371b4e30f1426 100644
> --- a/drivers/platform/x86/intel/pmc/tgl.c
> +++ b/drivers/platform/x86/intel/pmc/tgl.c
> @@ -197,6 +197,8 @@ const struct pmc_reg_map tgl_reg_map = {
>  	.ppfear_buckets = ICL_PPFEAR_NUM_ENTRIES,
>  	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
>  	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
> +	.acpi_pm_tmr_ctl_offset = SPT_PMC_ACPI_PM_TMR_CTL_OFFSET,
> +	.acpi_pm_tmr_disable_bit = SPT_PMC_BIT_ACPI_PM_TMR_DISABLE,
>  	.ltr_ignore_max = TGL_NUM_IP_IGN_ALLOWED,
>  	.lpm_num_maps = TGL_LPM_NUM_MAPS,
>  	.lpm_res_counter_step_x2 = TGL_PMC_LPM_RES_COUNTER_STEP_X2,
> diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
> index 0ad8b550bb4b4..f1953c5687683 100644
> --- a/include/linux/clocksource.h
> +++ b/include/linux/clocksource.h
> @@ -305,5 +305,7 @@ static inline unsigned int clocksource_get_max_watchdog_retry(void)
>  }
>  
>  void clocksource_verify_percpu(struct clocksource *cs);
> +void clocksource_current_cs_name(char *buf, size_t buf_size);
> +void clocksource_suspend_cs_name(char *buf, size_t buf_size);
>  
>  #endif /* _LINUX_CLOCKSOURCE_H */
> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
> index e5b260aa0e02c..e2e2609f7f4b2 100644
> --- a/kernel/time/clocksource.c
> +++ b/kernel/time/clocksource.c
> @@ -1320,6 +1320,28 @@ int clocksource_unregister(struct clocksource *cs)
>  }
>  EXPORT_SYMBOL(clocksource_unregister);
>  
> +void clocksource_suspend_cs_name(char *buf, size_t buf_size)
> +{
> +	mutex_lock(&clocksource_mutex);
> +
> +	buf[0] = '\0';
> +	if (suspend_clocksource)
> +		strscpy(buf, suspend_clocksource->name, buf_size);
> +
> +	mutex_unlock(&clocksource_mutex);
> +}
> +
> +void clocksource_current_cs_name(char *buf, size_t buf_size)
> +{
> +	mutex_lock(&clocksource_mutex);
> +
> +	buf[0] = '\0';
> +	if (curr_clocksource)
> +		strscpy(buf, curr_clocksource->name, buf_size);
> +
> +	mutex_unlock(&clocksource_mutex);
> +}

Have you tested allmodconfig build? These functions are not exported so
I'd expect it to fail...

One could use guard() for the mutex.

-- 
 i.