The domain attributes returned by the perf protocol can end up
reporting identical names across domains, resulting in debugfs
node creation failure. Fix this failure by ensuring that pm domains
get a unique name using ida in pm_genpd_init.
Logs: [X1E reports 'NCC' for all its scmi perf domains]
debugfs: Directory 'NCC' with parent 'pm_genpd' already present!
debugfs: Directory 'NCC' with parent 'pm_genpd' already present!
Reported-by: Johan Hovold <johan+linaro@kernel.org>
Closes: https://lore.kernel.org/lkml/ZoQjAWse2YxwyRJv@hovoldconsulting.com/
Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains")
Fix-suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
---
genpd names with ida appended:
power-domain-cpu0_0
power-domain-cpu1_1
....
ebi_18
gfx_19
...
NCC_56
NCC_57
NCC_58
genpd summary with ida appended:
domain status children performance
/device runtime status managed by
------------------------------------------------------------------------------
NCC_58 on 0
NCC_57 on 0
NCC_56 on 0
...
gfx_19 off-0 0
ebi_18 off-0 0
...
power-domain-cpu1_1 off-0 0
genpd:0:cpu1 suspended 0 SW
power-domain-cpu0_0 off-0 0
genpd:0:cpu0 suspended 0 SW
drivers/pmdomain/core.c | 40 ++++++++++++++++++++++++---------------
include/linux/pm_domain.h | 1 +
2 files changed, 26 insertions(+), 15 deletions(-)
diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 5ede0f7eda09..631cb732bb39 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -7,6 +7,7 @@
#define pr_fmt(fmt) "PM: " fmt
#include <linux/delay.h>
+#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/platform_device.h>
@@ -23,6 +24,9 @@
#include <linux/cpu.h>
#include <linux/debugfs.h>
+/* Provides a unique ID for each genpd device */
+static DEFINE_IDA(genpd_ida);
+
#define GENPD_RETRY_MAX_MS 250 /* Approximate */
#define GENPD_DEV_CALLBACK(genpd, type, callback, dev) \
@@ -189,7 +193,7 @@ static inline bool irq_safe_dev_in_sleep_domain(struct device *dev,
if (ret)
dev_warn_once(dev, "PM domain %s will not be powered off\n",
- genpd->name);
+ dev_name(&genpd->dev));
return ret;
}
@@ -274,7 +278,7 @@ static void genpd_debug_remove(struct generic_pm_domain *genpd)
if (!genpd_debugfs_dir)
return;
- debugfs_lookup_and_remove(genpd->name, genpd_debugfs_dir);
+ debugfs_lookup_and_remove(dev_name(&genpd->dev), genpd_debugfs_dir);
}
static void genpd_update_accounting(struct generic_pm_domain *genpd)
@@ -731,7 +735,7 @@ static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
genpd->states[state_idx].power_on_latency_ns = elapsed_ns;
genpd->gd->max_off_time_changed = true;
pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
- genpd->name, "on", elapsed_ns);
+ dev_name(&genpd->dev), "on", elapsed_ns);
out:
raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_ON, NULL);
@@ -782,7 +786,7 @@ static int _genpd_power_off(struct generic_pm_domain *genpd, bool timed)
genpd->states[state_idx].power_off_latency_ns = elapsed_ns;
genpd->gd->max_off_time_changed = true;
pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
- genpd->name, "off", elapsed_ns);
+ dev_name(&genpd->dev), "off", elapsed_ns);
out:
raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_OFF,
@@ -1940,7 +1944,7 @@ int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb)
if (ret) {
dev_warn(dev, "failed to add notifier for PM domain %s\n",
- genpd->name);
+ dev_name(&genpd->dev));
return ret;
}
@@ -1987,7 +1991,7 @@ int dev_pm_genpd_remove_notifier(struct device *dev)
if (ret) {
dev_warn(dev, "failed to remove notifier for PM domain %s\n",
- genpd->name);
+ dev_name(&genpd->dev));
return ret;
}
@@ -2013,7 +2017,7 @@ static int genpd_add_subdomain(struct generic_pm_domain *genpd,
*/
if (!genpd_is_irq_safe(genpd) && genpd_is_irq_safe(subdomain)) {
WARN(1, "Parent %s of subdomain %s must be IRQ safe\n",
- genpd->name, subdomain->name);
+ dev_name(&genpd->dev), subdomain->name);
return -EINVAL;
}
@@ -2088,7 +2092,7 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
if (!list_empty(&subdomain->parent_links) || subdomain->device_count) {
pr_warn("%s: unable to remove subdomain %s\n",
- genpd->name, subdomain->name);
+ dev_name(&genpd->dev), subdomain->name);
ret = -EBUSY;
goto out;
}
@@ -2264,8 +2268,13 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
if (ret)
return ret;
+ ret = ida_alloc(&genpd_ida, GFP_KERNEL);
+ if (ret < 0)
+ return ret;
+ genpd->device_id = ret;
+
device_initialize(&genpd->dev);
- dev_set_name(&genpd->dev, "%s", genpd->name);
+ dev_set_name(&genpd->dev, "%s_%u", genpd->name, genpd->device_id);
mutex_lock(&gpd_list_lock);
list_add(&genpd->gpd_list_node, &gpd_list);
@@ -2287,13 +2296,13 @@ static int genpd_remove(struct generic_pm_domain *genpd)
if (genpd->has_provider) {
genpd_unlock(genpd);
- pr_err("Provider present, unable to remove %s\n", genpd->name);
+ pr_err("Provider present, unable to remove %s\n", dev_name(&genpd->dev));
return -EBUSY;
}
if (!list_empty(&genpd->parent_links) || genpd->device_count) {
genpd_unlock(genpd);
- pr_err("%s: unable to remove %s\n", __func__, genpd->name);
+ pr_err("%s: unable to remove %s\n", __func__, dev_name(&genpd->dev));
return -EBUSY;
}
@@ -2307,9 +2316,10 @@ static int genpd_remove(struct generic_pm_domain *genpd)
genpd_unlock(genpd);
genpd_debug_remove(genpd);
cancel_work_sync(&genpd->power_off_work);
+ ida_free(&genpd_ida, genpd->device_id);
genpd_free_data(genpd);
- pr_debug("%s: removed %s\n", __func__, genpd->name);
+ pr_debug("%s: removed %s\n", __func__, dev_name(&genpd->dev));
return 0;
}
@@ -3272,12 +3282,12 @@ static int genpd_summary_one(struct seq_file *s,
else
snprintf(state, sizeof(state), "%s",
status_lookup[genpd->status]);
- seq_printf(s, "%-30s %-30s %u", genpd->name, state, genpd->performance_state);
+ seq_printf(s, "%-30s %-30s %u", dev_name(&genpd->dev), state, genpd->performance_state);
/*
* Modifications on the list require holding locks on both
* parent and child, so we are safe.
- * Also genpd->name is immutable.
+ * Also the device name is immutable.
*/
list_for_each_entry(link, &genpd->parent_links, parent_node) {
if (list_is_first(&link->parent_node, &genpd->parent_links))
@@ -3502,7 +3512,7 @@ static void genpd_debug_add(struct generic_pm_domain *genpd)
if (!genpd_debugfs_dir)
return;
- d = debugfs_create_dir(genpd->name, genpd_debugfs_dir);
+ d = debugfs_create_dir(dev_name(&genpd->dev), genpd_debugfs_dir);
debugfs_create_file("current_state", 0444,
d, genpd, &status_fops);
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index b637ec14025f..738df5296ec7 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -163,6 +163,7 @@ struct generic_pm_domain {
atomic_t sd_count; /* Number of subdomains with power "on" */
enum gpd_status status; /* Current state of the domain */
unsigned int device_count; /* Number of devices */
+ unsigned int device_id; /* unique device id */
unsigned int suspended_count; /* System suspend device counter */
unsigned int prepared_count; /* Suspend counter of prepared devices */
unsigned int performance_state; /* Aggregated max performance state */
--
2.34.1On Mon, Oct 07, 2024 at 11:36:41AM GMT, Sibi Sankar wrote:
> The domain attributes returned by the perf protocol can end up
> reporting identical names across domains, resulting in debugfs
> node creation failure. Fix this failure by ensuring that pm domains
> get a unique name using ida in pm_genpd_init.
Can we make this opt-in or opt-out? Seeing numeric suffixes next to
well-known power domain names (e.g. those comin from RPMh or the CPU
domains) is a bit strange. Or maybe you can limit the IDA suffix just to
the SCMI / perf domains?
>
> Logs: [X1E reports 'NCC' for all its scmi perf domains]
> debugfs: Directory 'NCC' with parent 'pm_genpd' already present!
> debugfs: Directory 'NCC' with parent 'pm_genpd' already present!
>
> Reported-by: Johan Hovold <johan+linaro@kernel.org>
> Closes: https://lore.kernel.org/lkml/ZoQjAWse2YxwyRJv@hovoldconsulting.com/
> Fixes: 718072ceb211 ("PM: domains: create debugfs nodes when adding power domains")
> Fix-suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Just "Suggested-by: ..."
> Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
> ---
>
> genpd names with ida appended:
> power-domain-cpu0_0
> power-domain-cpu1_1
> ....
> ebi_18
> gfx_19
> ...
> NCC_56
> NCC_57
> NCC_58
>
> genpd summary with ida appended:
> domain status children performance
> /device runtime status managed by
> ------------------------------------------------------------------------------
> NCC_58 on 0
> NCC_57 on 0
> NCC_56 on 0
> ...
> gfx_19 off-0 0
> ebi_18 off-0 0
> ...
> power-domain-cpu1_1 off-0 0
> genpd:0:cpu1 suspended 0 SW
> power-domain-cpu0_0 off-0 0
> genpd:0:cpu0 suspended 0 SW
>
> drivers/pmdomain/core.c | 40 ++++++++++++++++++++++++---------------
> include/linux/pm_domain.h | 1 +
> 2 files changed, 26 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
> index 5ede0f7eda09..631cb732bb39 100644
> --- a/drivers/pmdomain/core.c
> +++ b/drivers/pmdomain/core.c
> @@ -7,6 +7,7 @@
> #define pr_fmt(fmt) "PM: " fmt
>
> #include <linux/delay.h>
> +#include <linux/idr.h>
> #include <linux/kernel.h>
> #include <linux/io.h>
> #include <linux/platform_device.h>
> @@ -23,6 +24,9 @@
> #include <linux/cpu.h>
> #include <linux/debugfs.h>
>
> +/* Provides a unique ID for each genpd device */
> +static DEFINE_IDA(genpd_ida);
> +
> #define GENPD_RETRY_MAX_MS 250 /* Approximate */
>
> #define GENPD_DEV_CALLBACK(genpd, type, callback, dev) \
> @@ -189,7 +193,7 @@ static inline bool irq_safe_dev_in_sleep_domain(struct device *dev,
>
> if (ret)
> dev_warn_once(dev, "PM domain %s will not be powered off\n",
> - genpd->name);
> + dev_name(&genpd->dev));
>
> return ret;
> }
> @@ -274,7 +278,7 @@ static void genpd_debug_remove(struct generic_pm_domain *genpd)
> if (!genpd_debugfs_dir)
> return;
>
> - debugfs_lookup_and_remove(genpd->name, genpd_debugfs_dir);
> + debugfs_lookup_and_remove(dev_name(&genpd->dev), genpd_debugfs_dir);
> }
>
> static void genpd_update_accounting(struct generic_pm_domain *genpd)
> @@ -731,7 +735,7 @@ static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
> genpd->states[state_idx].power_on_latency_ns = elapsed_ns;
> genpd->gd->max_off_time_changed = true;
> pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
> - genpd->name, "on", elapsed_ns);
> + dev_name(&genpd->dev), "on", elapsed_ns);
>
> out:
> raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_ON, NULL);
> @@ -782,7 +786,7 @@ static int _genpd_power_off(struct generic_pm_domain *genpd, bool timed)
> genpd->states[state_idx].power_off_latency_ns = elapsed_ns;
> genpd->gd->max_off_time_changed = true;
> pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
> - genpd->name, "off", elapsed_ns);
> + dev_name(&genpd->dev), "off", elapsed_ns);
>
> out:
> raw_notifier_call_chain(&genpd->power_notifiers, GENPD_NOTIFY_OFF,
> @@ -1940,7 +1944,7 @@ int dev_pm_genpd_add_notifier(struct device *dev, struct notifier_block *nb)
>
> if (ret) {
> dev_warn(dev, "failed to add notifier for PM domain %s\n",
> - genpd->name);
> + dev_name(&genpd->dev));
> return ret;
> }
>
> @@ -1987,7 +1991,7 @@ int dev_pm_genpd_remove_notifier(struct device *dev)
>
> if (ret) {
> dev_warn(dev, "failed to remove notifier for PM domain %s\n",
> - genpd->name);
> + dev_name(&genpd->dev));
> return ret;
> }
>
> @@ -2013,7 +2017,7 @@ static int genpd_add_subdomain(struct generic_pm_domain *genpd,
> */
> if (!genpd_is_irq_safe(genpd) && genpd_is_irq_safe(subdomain)) {
> WARN(1, "Parent %s of subdomain %s must be IRQ safe\n",
> - genpd->name, subdomain->name);
> + dev_name(&genpd->dev), subdomain->name);
> return -EINVAL;
> }
>
> @@ -2088,7 +2092,7 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
>
> if (!list_empty(&subdomain->parent_links) || subdomain->device_count) {
> pr_warn("%s: unable to remove subdomain %s\n",
> - genpd->name, subdomain->name);
> + dev_name(&genpd->dev), subdomain->name);
> ret = -EBUSY;
> goto out;
> }
> @@ -2264,8 +2268,13 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
> if (ret)
> return ret;
>
> + ret = ida_alloc(&genpd_ida, GFP_KERNEL);
> + if (ret < 0)
> + return ret;
> + genpd->device_id = ret;
> +
> device_initialize(&genpd->dev);
> - dev_set_name(&genpd->dev, "%s", genpd->name);
> + dev_set_name(&genpd->dev, "%s_%u", genpd->name, genpd->device_id);
>
> mutex_lock(&gpd_list_lock);
> list_add(&genpd->gpd_list_node, &gpd_list);
> @@ -2287,13 +2296,13 @@ static int genpd_remove(struct generic_pm_domain *genpd)
>
> if (genpd->has_provider) {
> genpd_unlock(genpd);
> - pr_err("Provider present, unable to remove %s\n", genpd->name);
> + pr_err("Provider present, unable to remove %s\n", dev_name(&genpd->dev));
> return -EBUSY;
> }
>
> if (!list_empty(&genpd->parent_links) || genpd->device_count) {
> genpd_unlock(genpd);
> - pr_err("%s: unable to remove %s\n", __func__, genpd->name);
> + pr_err("%s: unable to remove %s\n", __func__, dev_name(&genpd->dev));
> return -EBUSY;
> }
>
> @@ -2307,9 +2316,10 @@ static int genpd_remove(struct generic_pm_domain *genpd)
> genpd_unlock(genpd);
> genpd_debug_remove(genpd);
> cancel_work_sync(&genpd->power_off_work);
> + ida_free(&genpd_ida, genpd->device_id);
> genpd_free_data(genpd);
>
> - pr_debug("%s: removed %s\n", __func__, genpd->name);
> + pr_debug("%s: removed %s\n", __func__, dev_name(&genpd->dev));
>
> return 0;
> }
> @@ -3272,12 +3282,12 @@ static int genpd_summary_one(struct seq_file *s,
> else
> snprintf(state, sizeof(state), "%s",
> status_lookup[genpd->status]);
> - seq_printf(s, "%-30s %-30s %u", genpd->name, state, genpd->performance_state);
> + seq_printf(s, "%-30s %-30s %u", dev_name(&genpd->dev), state, genpd->performance_state);
>
> /*
> * Modifications on the list require holding locks on both
> * parent and child, so we are safe.
> - * Also genpd->name is immutable.
> + * Also the device name is immutable.
> */
> list_for_each_entry(link, &genpd->parent_links, parent_node) {
> if (list_is_first(&link->parent_node, &genpd->parent_links))
> @@ -3502,7 +3512,7 @@ static void genpd_debug_add(struct generic_pm_domain *genpd)
> if (!genpd_debugfs_dir)
> return;
>
> - d = debugfs_create_dir(genpd->name, genpd_debugfs_dir);
> + d = debugfs_create_dir(dev_name(&genpd->dev), genpd_debugfs_dir);
>
> debugfs_create_file("current_state", 0444,
> d, genpd, &status_fops);
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index b637ec14025f..738df5296ec7 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -163,6 +163,7 @@ struct generic_pm_domain {
> atomic_t sd_count; /* Number of subdomains with power "on" */
> enum gpd_status status; /* Current state of the domain */
> unsigned int device_count; /* Number of devices */
> + unsigned int device_id; /* unique device id */
> unsigned int suspended_count; /* System suspend device counter */
> unsigned int prepared_count; /* Suspend counter of prepared devices */
> unsigned int performance_state; /* Aggregated max performance state */
> --
> 2.34.1
>
--
With best wishes
Dmitry
On Mon, 7 Oct 2024 at 19:33, Dmitry Baryshkov <dmitry.baryshkov@linaro.org> wrote: > > On Mon, Oct 07, 2024 at 11:36:41AM GMT, Sibi Sankar wrote: > > The domain attributes returned by the perf protocol can end up > > reporting identical names across domains, resulting in debugfs > > node creation failure. Fix this failure by ensuring that pm domains > > get a unique name using ida in pm_genpd_init. Thanks for working on this! > > Can we make this opt-in or opt-out? Seeing numeric suffixes next to > well-known power domain names (e.g. those comin from RPMh or the CPU > domains) is a bit strange. Or maybe you can limit the IDA suffix just to > the SCMI / perf domains? I was also thinking something along the lines of this. Another thing on top of what Dmitry suggests, could be to iterate through the &gpd_list and compare the existing genpd->names with the one that we are adding in pm_genpd_init(). In this way, we don't need to add the IDA to more than those that really need it. What do you think? [...] Kind regards Uffe
On Wed, Oct 09, 2024 at 01:11:14PM GMT, Ulf Hansson wrote: > On Mon, 7 Oct 2024 at 19:33, Dmitry Baryshkov > <dmitry.baryshkov@linaro.org> wrote: > > > > On Mon, Oct 07, 2024 at 11:36:41AM GMT, Sibi Sankar wrote: > > > The domain attributes returned by the perf protocol can end up > > > reporting identical names across domains, resulting in debugfs > > > node creation failure. Fix this failure by ensuring that pm domains > > > get a unique name using ida in pm_genpd_init. > > Thanks for working on this! > > > > > Can we make this opt-in or opt-out? Seeing numeric suffixes next to > > well-known power domain names (e.g. those comin from RPMh or the CPU > > domains) is a bit strange. Or maybe you can limit the IDA suffix just to > > the SCMI / perf domains? > > I was also thinking something along the lines of this. > > Another thing on top of what Dmitry suggests, could be to iterate > through the &gpd_list and compare the existing genpd->names with the > one that we are adding in pm_genpd_init(). In this way, we don't need > to add the IDA to more than those that really need it. > > What do you think? I have no strong preference. Your proposal sounds good to me too. > > [...] > > Kind regards > Uffe -- With best wishes Dmitry
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