[PATCH v10 22/24] x86/resctrl: Update assignments on event configuration changes

[Babu Moger]

Resctrl provides option to configure events by writing to the interfaces
/sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config or
/sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config when BMEC (Bandwidth
Monitoring Event Configuration) is supported.

Whenever the event configuration is updated, MBM assignments must be
revised across all monitor groups within the impacted domains.

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v10: Code changed completely with domain specific counter assignment.
     Rewrite the commit message.
     Added few more code comments.

v9: Again patch changed completely based on the comment.
    https://lore.kernel.org/lkml/03b278b5-6c15-4d09-9ab7-3317e84a409e@xxxxxxxxx/
    Introduced resctrl_mon_event_config_set to handle IPI.
    But sending another IPI inside IPI causes problem. Kernel reports SMP
    warning. So, introduced resctrl_arch_update_cntr() to send the command directly.

v8: Patch changed completely.
    Updated the assignment on same IPI as the event is updated.
    Could not do the way we discussed in the thread.
    https://lore.kernel.org/lkml/f77737ac-d3f6-3e4b-3565-564f79c86ca8@xxxxxxx/
    Needed to figure out event type to update the configuration.

v7: New patch to update the assignments. Missed it earlier.
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 67 ++++++++++++++++++++++----
 include/linux/resctrl.h                |  4 +-
 2 files changed, 61 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 65b3556978ad..6b5c886b7e99 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1704,26 +1704,26 @@ u32 resctrl_arch_mon_event_config_get(struct rdt_mon_domain *d,
 	return INVALID_CONFIG_VALUE;
 }
 
-void resctrl_arch_mon_event_config_set(void *info)
+void resctrl_arch_mon_event_config_set(struct rdt_mon_domain *d,
+				       enum resctrl_event_id eventid, u32 val)
 {
-	struct mon_config_info *mon_info = info;
 	struct rdt_hw_mon_domain *hw_dom;
 	unsigned int index;
 
-	index = mon_event_config_index_get(mon_info->evtid);
+	index = mon_event_config_index_get(eventid);
 	if (index == INVALID_CONFIG_INDEX)
 		return;
 
-	wrmsr(MSR_IA32_EVT_CFG_BASE + index, mon_info->mon_config, 0);
+	wrmsr(MSR_IA32_EVT_CFG_BASE + index, val, 0);
 
-	hw_dom = resctrl_to_arch_mon_dom(mon_info->d);
+	hw_dom = resctrl_to_arch_mon_dom(d);
 
-	switch (mon_info->evtid) {
+	switch (eventid) {
 	case QOS_L3_MBM_TOTAL_EVENT_ID:
-		hw_dom->mbm_total_cfg = mon_info->mon_config;
+		hw_dom->mbm_total_cfg = val;
 		break;
 	case QOS_L3_MBM_LOCAL_EVENT_ID:
-		hw_dom->mbm_local_cfg = mon_info->mon_config;
+		hw_dom->mbm_local_cfg = val;
 		break;
 	default:
 		break;
@@ -1825,6 +1825,54 @@ static int mbm_local_bytes_config_show(struct kernfs_open_file *of,
 	return 0;
 }
 
+/*
+ * Review the cntr_cfg domain configuration. If a matching assignment is found,
+ * update the counter assignment accordingly. This is within the IPI Context,
+ * so call resctrl_abmc_config_one_amd directly.
+ */
+static void resctrl_arch_update_cntr(struct rdt_resource *r, struct rdt_mon_domain *d,
+				     enum resctrl_event_id evtid, u32 val)
+{
+	struct cntr_config config;
+	struct rdtgroup *rdtgrp;
+	struct mbm_state *m;
+	u32 cntr_id;
+
+	for (cntr_id = 0; cntr_id < r->mon.num_mbm_cntrs; cntr_id++) {
+		rdtgrp = d->cntr_cfg[cntr_id].rdtgrp;
+		if (rdtgrp && d->cntr_cfg[cntr_id].evtid == evtid) {
+			memset(&config, 0, sizeof(struct cntr_config));
+			config.r = r;
+			config.d = d;
+			config.evtid = evtid;
+			config.rmid = rdtgrp->mon.rmid;
+			config.closid = rdtgrp->closid;
+			config.cntr_id = cntr_id;
+			config.val = val;
+			config.assign = 1;
+
+			resctrl_abmc_config_one_amd(&config);
+
+			m = get_mbm_state(d, rdtgrp->closid, rdtgrp->mon.rmid, evtid);
+			if (m)
+				memset(m, 0, sizeof(struct mbm_state));
+		}
+	}
+}
+
+static void resctrl_mon_event_config_set(void *info)
+{
+	struct mon_config_info *mon_info = info;
+	struct rdt_mon_domain *d = mon_info->d;
+	struct rdt_resource *r = mon_info->r;
+
+	resctrl_arch_mon_event_config_set(d, mon_info->evtid, mon_info->mon_config);
+
+	/* Check if assignments needs to be updated */
+	if (resctrl_arch_mbm_cntr_assign_enabled(r))
+		resctrl_arch_update_cntr(r, d, mon_info->evtid,
+					 mon_info->mon_config);
+}
 
 static void mbm_config_write_domain(struct rdt_resource *r,
 				    struct rdt_mon_domain *d, u32 evtid, u32 val)
@@ -1840,6 +1888,7 @@ static void mbm_config_write_domain(struct rdt_resource *r,
 	if (config_val == INVALID_CONFIG_VALUE || config_val == val)
 		return;
 
+	mon_info.r = r;
 	mon_info.d = d;
 	mon_info.evtid = evtid;
 	mon_info.mon_config = val;
@@ -1851,7 +1900,7 @@ static void mbm_config_write_domain(struct rdt_resource *r,
 	 * on one CPU is observed by all the CPUs in the domain.
 	 */
 	smp_call_function_any(&d->hdr.cpu_mask,
-			      resctrl_arch_mon_event_config_set,
+			      resctrl_mon_event_config_set,
 			      &mon_info, 1);
 
 	/*
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 03c67d9156f3..2bf461179680 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -137,6 +137,7 @@ struct rdt_mon_domain {
  * @mon_config:		Event configuration value
  */
 struct mon_config_info {
+	struct rdt_resource *r;
 	struct rdt_mon_domain *d;
 	enum resctrl_event_id evtid;
 	u32 mon_config;
@@ -376,7 +377,8 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_mon_domain *d,
  */
 void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_mon_domain *d);
 
-void resctrl_arch_mon_event_config_set(void *info);
+void resctrl_arch_mon_event_config_set(struct rdt_mon_domain *d,
+				       enum resctrl_event_id eventid, u32 val);
 u32 resctrl_arch_mon_event_config_get(struct rdt_mon_domain *d,
 				      enum resctrl_event_id eventid);
 
-- 
2.34.1