[PATCH v2 34/45] arm_mpam: resctrl: Add resctrl_arch_rmid_read() and resctrl_arch_reset_rmid()

Ben Horgan posted 45 patches 1 month, 3 weeks ago
There is a newer version of this series
[PATCH v2 34/45] arm_mpam: resctrl: Add resctrl_arch_rmid_read() and resctrl_arch_reset_rmid()
Posted by Ben Horgan 1 month, 3 weeks ago
From: James Morse <james.morse@arm.com>

resctrl uses resctrl_arch_rmid_read() to read counters. CDP emulation means
the counter may need reading in three different ways. The same goes for
reset.

The helpers behind the resctrl_arch_ functions will be re-used for the ABMC
equivalent functions.

Add the rounding helper for checking monitor values while we're here.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
---
Changes since rfc:
cfg intialisation style
code flow at end of read_mon_cdp_safe()
---
 drivers/resctrl/mpam_resctrl.c | 159 +++++++++++++++++++++++++++++++++
 include/linux/arm_mpam.h       |   5 ++
 2 files changed, 164 insertions(+)

diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index 638c84cdcfb6..8a1263986145 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -354,6 +354,165 @@ void resctrl_arch_mon_ctx_free(struct rdt_resource *r,
 	resctrl_arch_mon_ctx_free_no_wait(evtid, mon_idx);
 }
 
+static int
+__read_mon(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
+	   enum mpam_device_features mon_type,
+	   int mon_idx,
+	   enum resctrl_conf_type cdp_type, u32 closid, u32 rmid, u64 *val)
+{
+	struct mon_cfg cfg;
+
+	if (!mpam_is_enabled())
+		return -EINVAL;
+
+	/* Shift closid to account for CDP */
+	closid = resctrl_get_config_index(closid, cdp_type);
+
+	if (mon_idx == USE_PRE_ALLOCATED) {
+		int mbwu_idx = resctrl_arch_rmid_idx_encode(closid, rmid);
+
+		mon_idx = mon->mbwu_idx_to_mon[mbwu_idx];
+		if (mon_idx == -1) {
+			if (mpam_resctrl_abmc_enabled()) {
+				/* Report Unassigned */
+				return -ENOENT;
+			}
+			/* Report Unavailable */
+			return -EINVAL;
+		}
+	}
+
+	if (irqs_disabled()) {
+		/* Check if we can access this domain without an IPI */
+		return -EIO;
+	}
+
+	cfg = (struct mon_cfg) {
+		.mon = mon_idx,
+		.match_pmg = true,
+		.partid = closid,
+		.pmg = rmid,
+	};
+
+	return mpam_msmon_read(mon_comp, &cfg, mon_type, val);
+}
+
+static int read_mon_cdp_safe(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
+			     enum mpam_device_features mon_type,
+			     int mon_idx, u32 closid, u32 rmid, u64 *val)
+{
+	if (cdp_enabled) {
+		u64 code_val = 0, data_val = 0;
+		int err;
+
+		err = __read_mon(mon, mon_comp, mon_type, mon_idx,
+				 CDP_CODE, closid, rmid, &code_val);
+		if (err)
+			return err;
+
+		err = __read_mon(mon, mon_comp, mon_type, mon_idx,
+				 CDP_DATA, closid, rmid, &data_val);
+		if (err)
+			return err;
+
+		*val += code_val + data_val;
+		return 0;
+	}
+
+	return __read_mon(mon, mon_comp, mon_type, mon_idx,
+			  CDP_NONE, closid, rmid, val);
+}
+
+/* MBWU when not in ABMC mode, and CSU counters. */
+int resctrl_arch_rmid_read(struct rdt_resource	*r, struct rdt_mon_domain *d,
+			   u32 closid, u32 rmid, enum resctrl_event_id eventid,
+			   u64 *val, void *arch_mon_ctx)
+{
+	struct mpam_resctrl_dom *l3_dom;
+	struct mpam_component *mon_comp;
+	u32 mon_idx = *(u32 *)arch_mon_ctx;
+	enum mpam_device_features mon_type;
+	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[eventid];
+
+	resctrl_arch_rmid_read_context_check();
+
+	if (eventid >= QOS_NUM_EVENTS || !mon->class)
+		return -EINVAL;
+
+	l3_dom = container_of(d, struct mpam_resctrl_dom, resctrl_mon_dom);
+	mon_comp = l3_dom->mon_comp[eventid];
+
+	switch (eventid) {
+	case QOS_L3_OCCUP_EVENT_ID:
+		mon_type = mpam_feat_msmon_csu;
+		break;
+	case QOS_L3_MBM_LOCAL_EVENT_ID:
+	case QOS_L3_MBM_TOTAL_EVENT_ID:
+		mon_type = mpam_feat_msmon_mbwu;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return read_mon_cdp_safe(mon, mon_comp, mon_type, mon_idx,
+				 closid, rmid, val);
+}
+
+static void __reset_mon(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
+			int mon_idx,
+			enum resctrl_conf_type cdp_type, u32 closid, u32 rmid)
+{
+	struct mon_cfg cfg = { };
+
+	if (!mpam_is_enabled())
+		return;
+
+	/* Shift closid to account for CDP */
+	closid = resctrl_get_config_index(closid, cdp_type);
+
+	if (mon_idx == USE_PRE_ALLOCATED) {
+		int mbwu_idx = resctrl_arch_rmid_idx_encode(closid, rmid);
+		mon_idx = mon->mbwu_idx_to_mon[mbwu_idx];
+	}
+
+	if (mon_idx == -1)
+		return;
+	cfg.mon = mon_idx;
+	mpam_msmon_reset_mbwu(mon_comp, &cfg);
+}
+
+static void reset_mon_cdp_safe(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
+			       int mon_idx, u32 closid, u32 rmid)
+{
+	if (cdp_enabled) {
+		__reset_mon(mon, mon_comp, mon_idx, CDP_CODE, closid, rmid);
+		__reset_mon(mon, mon_comp, mon_idx, CDP_DATA, closid, rmid);
+	} else {
+		__reset_mon(mon, mon_comp, mon_idx, CDP_NONE, closid, rmid);
+	}
+}
+
+/* Called via IPI. Call with read_cpus_lock() held. */
+void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_mon_domain *d,
+			     u32 closid, u32 rmid, enum resctrl_event_id eventid)
+{
+	struct mpam_resctrl_dom *l3_dom;
+	struct mpam_component *mon_comp;
+	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[eventid];
+
+	if (!mpam_is_enabled())
+		return;
+
+	/* Only MBWU counters are relevant, and for supported event types. */
+	if (eventid == QOS_L3_OCCUP_EVENT_ID || !mon->class)
+		return;
+
+	l3_dom = container_of(d, struct mpam_resctrl_dom, resctrl_mon_dom);
+	mon_comp = l3_dom->mon_comp[eventid];
+
+	reset_mon_cdp_safe(mon, mon_comp, USE_PRE_ALLOCATED, closid, rmid);
+}
+
 static bool cache_has_usable_cpor(struct mpam_class *class)
 {
 	struct mpam_props *cprops = &class->props;
diff --git a/include/linux/arm_mpam.h b/include/linux/arm_mpam.h
index e1461e32af75..86d5e326d2bd 100644
--- a/include/linux/arm_mpam.h
+++ b/include/linux/arm_mpam.h
@@ -67,6 +67,11 @@ struct rdt_resource;
 void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, enum resctrl_event_id evtid);
 void resctrl_arch_mon_ctx_free(struct rdt_resource *r, enum resctrl_event_id evtid, void *ctx);
 
+static inline unsigned int resctrl_arch_round_mon_val(unsigned int val)
+{
+	return val;
+}
+
 /**
  * mpam_register_requestor() - Register a requestor with the MPAM driver
  * @partid_max:		The maximum PARTID value the requestor can generate.
-- 
2.43.0
Re: [PATCH v2 34/45] arm_mpam: resctrl: Add resctrl_arch_rmid_read() and resctrl_arch_reset_rmid()
Posted by Jonathan Cameron 1 month ago
On Fri, 19 Dec 2025 18:11:36 +0000
Ben Horgan <ben.horgan@arm.com> wrote:

> From: James Morse <james.morse@arm.com>
> 
> resctrl uses resctrl_arch_rmid_read() to read counters. CDP emulation means
> the counter may need reading in three different ways. The same goes for
> reset.
> 
> The helpers behind the resctrl_arch_ functions will be re-used for the ABMC
> equivalent functions.
> 
> Add the rounding helper for checking monitor values while we're here.
> 
> Signed-off-by: James Morse <james.morse@arm.com>
> Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Trivial stuff only.
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

> ---
> Changes since rfc:
> cfg intialisation style
> code flow at end of read_mon_cdp_safe()
> ---
>  drivers/resctrl/mpam_resctrl.c | 159 +++++++++++++++++++++++++++++++++
>  include/linux/arm_mpam.h       |   5 ++
>  2 files changed, 164 insertions(+)
> 
> diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
> index 638c84cdcfb6..8a1263986145 100644
> --- a/drivers/resctrl/mpam_resctrl.c
> +++ b/drivers/resctrl/mpam_resctrl.c
> @@ -354,6 +354,165 @@ void resctrl_arch_mon_ctx_free(struct rdt_resource *r,
>  	resctrl_arch_mon_ctx_free_no_wait(evtid, mon_idx);
>  }
>  
> +static int
Whilst I don't really care, this does seem inconsistent from other functions
static int __read_mon(...
probably for consistent looking code.

> +__read_mon(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
> +	   enum mpam_device_features mon_type,
> +	   int mon_idx,
> +	   enum resctrl_conf_type cdp_type, u32 closid, u32 rmid, u64 *val)
> +{
> +	struct mon_cfg cfg;
> +
> +	if (!mpam_is_enabled())
> +		return -EINVAL;
> +
> +	/* Shift closid to account for CDP */
> +	closid = resctrl_get_config_index(closid, cdp_type);
> +
> +	if (mon_idx == USE_PRE_ALLOCATED) {
> +		int mbwu_idx = resctrl_arch_rmid_idx_encode(closid, rmid);
> +
> +		mon_idx = mon->mbwu_idx_to_mon[mbwu_idx];
> +		if (mon_idx == -1) {
> +			if (mpam_resctrl_abmc_enabled()) {
> +				/* Report Unassigned */
> +				return -ENOENT;
> +			}
> +			/* Report Unavailable */
> +			return -EINVAL;
> +		}
> +	}
> +
> +	if (irqs_disabled()) {
> +		/* Check if we can access this domain without an IPI */
> +		return -EIO;
> +	}
> +
> +	cfg = (struct mon_cfg) {
> +		.mon = mon_idx,
> +		.match_pmg = true,
> +		.partid = closid,
> +		.pmg = rmid,
> +	};
> +
> +	return mpam_msmon_read(mon_comp, &cfg, mon_type, val);
> +}

> +/* MBWU when not in ABMC mode, and CSU counters. */
> +int resctrl_arch_rmid_read(struct rdt_resource	*r, struct rdt_mon_domain *d,

Odd tab before *r.

> +			   u32 closid, u32 rmid, enum resctrl_event_id eventid,
> +			   u64 *val, void *arch_mon_ctx)
> +{
> +	struct mpam_resctrl_dom *l3_dom;
> +	struct mpam_component *mon_comp;
> +	u32 mon_idx = *(u32 *)arch_mon_ctx;
> +	enum mpam_device_features mon_type;
> +	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[eventid];
> +
> +	resctrl_arch_rmid_read_context_check();
> +
> +	if (eventid >= QOS_NUM_EVENTS || !mon->class)
> +		return -EINVAL;
> +
> +	l3_dom = container_of(d, struct mpam_resctrl_dom, resctrl_mon_dom);
> +	mon_comp = l3_dom->mon_comp[eventid];
> +
> +	switch (eventid) {
> +	case QOS_L3_OCCUP_EVENT_ID:
> +		mon_type = mpam_feat_msmon_csu;
> +		break;
> +	case QOS_L3_MBM_LOCAL_EVENT_ID:
> +	case QOS_L3_MBM_TOTAL_EVENT_ID:
> +		mon_type = mpam_feat_msmon_mbwu;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return read_mon_cdp_safe(mon, mon_comp, mon_type, mon_idx,
> +				 closid, rmid, val);
> +}