fs/resctrl: Make event details accessible to functions when reading events

Reading monitoring event data from MMIO requires more context than the event id
to be able to read the correct memory location. struct mon_evt is the appropriate
place for this event specific context.

Prepare for addition of extra fields to struct mon_evt by changing the calling
conventions to pass a pointer to the mon_evt structure instead of just the
event id.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com

Author: aegl

fs/resctrl/ctrlmondata.c

@@ -552,7 +552,7 @@ struct rdt_domain_hdr *resctrl_find_domain(struct list_head *h, int id,
 
 void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
 		    struct rdt_domain_hdr *hdr, struct rdtgroup *rdtgrp,
-		    cpumask_t *cpumask, int evtid, int first)
+		    cpumask_t *cpumask, struct mon_evt *evt, int first)
 {
 	int cpu;
 
@@ -563,15 +563,15 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
 	 * Setup the parameters to pass to mon_event_count() to read the data.
 	 */
 	rr->rgrp = rdtgrp;
-	rr->evtid = evtid;
+	rr->evt = evt;
 	rr->r = r;
 	rr->hdr = hdr;
 	rr->first = first;
 	if (resctrl_arch_mbm_cntr_assign_enabled(r) &&
-	    resctrl_is_mbm_event(evtid)) {
+	    resctrl_is_mbm_event(evt->evtid)) {
 		rr->is_mbm_cntr = true;
 	} else {
-		rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evtid);
+		rr->arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, evt->evtid);
 		if (IS_ERR(rr->arch_mon_ctx)) {
 			rr->err = -EINVAL;
 			return;
@@ -592,21 +592,21 @@ void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
 		smp_call_on_cpu(cpu, smp_mon_event_count, rr, false);
 
 	if (rr->arch_mon_ctx)
-		resctrl_arch_mon_ctx_free(r, evtid, rr->arch_mon_ctx);
+		resctrl_arch_mon_ctx_free(r, evt->evtid, rr->arch_mon_ctx);
 }
 
 int rdtgroup_mondata_show(struct seq_file *m, void *arg)
 {
 	struct kernfs_open_file *of = m->private;
 	enum resctrl_res_level resid;
-	enum resctrl_event_id evtid;
 	struct rdt_l3_mon_domain *d;
 	struct rdt_domain_hdr *hdr;
 	struct rmid_read rr = {0};
 	struct rdtgroup *rdtgrp;
 	int domid, cpu, ret = 0;
 	struct rdt_resource *r;
 	struct cacheinfo *ci;
+	struct mon_evt *evt;
 	struct mon_data *md;
 
 	rdtgrp = rdtgroup_kn_lock_live(of->kn);
@@ -623,7 +623,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg)
 
 	resid = md->rid;
 	domid = md->domid;
-	evtid = md->evtid;
+	evt = md->evt;
 	r = resctrl_arch_get_resource(resid);
 
 	if (md->sum) {
@@ -641,7 +641,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg)
 					continue;
 				rr.ci = ci;
 				mon_event_read(&rr, r, NULL, rdtgrp,
-					       &ci->shared_cpu_map, evtid, false);
+					       &ci->shared_cpu_map, evt, false);
 				goto checkresult;
 			}
 		}
@@ -657,7 +657,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg)
 			ret = -ENOENT;
 			goto out;
 		}
-		mon_event_read(&rr, r, hdr, rdtgrp, &hdr->cpu_mask, evtid, false);
+		mon_event_read(&rr, r, hdr, rdtgrp, &hdr->cpu_mask, evt, false);
 	}
 
 checkresult:

fs/resctrl/internal.h

@@ -81,7 +81,7 @@ extern struct mon_evt mon_event_all[QOS_NUM_EVENTS];
  * struct mon_data - Monitoring details for each event file.
  * @list:            Member of the global @mon_data_kn_priv_list list.
  * @rid:             Resource id associated with the event file.
- * @evtid:           Event id associated with the event file.
+ * @evt:             Event structure associated with the event file.
  * @sum:             Set when event must be summed across multiple
  *                   domains.
  * @domid:           When @sum is zero this is the domain to which
@@ -95,7 +95,7 @@ extern struct mon_evt mon_event_all[QOS_NUM_EVENTS];
 struct mon_data {
 	struct list_head	list;
 	enum resctrl_res_level	rid;
-	enum resctrl_event_id	evtid;
+	struct mon_evt		*evt;
 	int			domid;
 	bool			sum;
 };
@@ -108,7 +108,7 @@ struct mon_data {
  * @r:	   Resource describing the properties of the event being read.
  * @hdr:   Header of domain that the counter should be read from. If NULL then
  *	   sum all domains in @r sharing L3 @ci.id
- * @evtid: Which monitor event to read.
+ * @evt:   Which monitor event to read.
  * @first: Initialize MBM counter when true.
  * @ci:    Cacheinfo for L3. Only set when @hdr is NULL. Used when summing
  *	   domains.
@@ -126,7 +126,7 @@ struct rmid_read {
 	struct rdtgroup		*rgrp;
 	struct rdt_resource	*r;
 	struct rdt_domain_hdr	*hdr;
-	enum resctrl_event_id	evtid;
+	struct mon_evt		*evt;
 	bool			first;
 	struct cacheinfo	*ci;
 	bool			is_mbm_cntr;
@@ -367,7 +367,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg);
 
 void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
 		    struct rdt_domain_hdr *hdr, struct rdtgroup *rdtgrp,
-		    cpumask_t *cpumask, int evtid, int first);
+		    cpumask_t *cpumask, struct mon_evt *evt, int first);
 
 void mbm_setup_overflow_handler(struct rdt_l3_mon_domain *dom,
 				unsigned long delay_ms,

fs/resctrl/monitor.c

@@ -430,7 +430,7 @@ static int __l3_mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr)
 	d = container_of(rr->hdr, struct rdt_l3_mon_domain, hdr);
 
 	if (rr->is_mbm_cntr) {
-		cntr_id = mbm_cntr_get(rr->r, d, rdtgrp, rr->evtid);
+		cntr_id = mbm_cntr_get(rr->r, d, rdtgrp, rr->evt->evtid);
 		if (cntr_id < 0) {
 			rr->err = -ENOENT;
 			return -EINVAL;
@@ -439,10 +439,10 @@ static int __l3_mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr)
 
 	if (rr->first) {
 		if (rr->is_mbm_cntr)
-			resctrl_arch_reset_cntr(rr->r, d, closid, rmid, cntr_id, rr->evtid);
+			resctrl_arch_reset_cntr(rr->r, d, closid, rmid, cntr_id, rr->evt->evtid);
 		else
-			resctrl_arch_reset_rmid(rr->r, d, closid, rmid, rr->evtid);
-		m = get_mbm_state(d, closid, rmid, rr->evtid);
+			resctrl_arch_reset_rmid(rr->r, d, closid, rmid, rr->evt->evtid);
+		m = get_mbm_state(d, closid, rmid, rr->evt->evtid);
 		if (m)
 			memset(m, 0, sizeof(struct mbm_state));
 		return 0;
@@ -453,10 +453,10 @@ static int __l3_mon_event_count(struct rdtgroup *rdtgrp, struct rmid_read *rr)
 		return -EINVAL;
 	if (rr->is_mbm_cntr)
 		rr->err = resctrl_arch_cntr_read(rr->r, d, closid, rmid, cntr_id,
-						 rr->evtid, &tval);
+						 rr->evt->evtid, &tval);
 	else
 		rr->err = resctrl_arch_rmid_read(rr->r, rr->hdr, closid, rmid,
-						 rr->evtid, &tval, rr->arch_mon_ctx);
+						 rr->evt->evtid, &tval, rr->arch_mon_ctx);
 	if (rr->err)
 		return rr->err;
 
@@ -501,7 +501,7 @@ static int __l3_mon_event_count_sum(struct rdtgroup *rdtgrp, struct rmid_read *r
 		if (d->ci_id != rr->ci->id)
 			continue;
 		err = resctrl_arch_rmid_read(rr->r, &d->hdr, closid, rmid,
-					     rr->evtid, &tval, rr->arch_mon_ctx);
+					     rr->evt->evtid, &tval, rr->arch_mon_ctx);
 		if (!err) {
 			rr->val += tval;
 			ret = 0;
@@ -551,7 +551,7 @@ static void mbm_bw_count(struct rdtgroup *rdtgrp, struct rmid_read *rr)
 	if (!domain_header_is_valid(rr->hdr, RESCTRL_MON_DOMAIN, RDT_RESOURCE_L3))
 		return;
 	d = container_of(rr->hdr, struct rdt_l3_mon_domain, hdr);
-	m = get_mbm_state(d, closid, rmid, rr->evtid);
+	m = get_mbm_state(d, closid, rmid, rr->evt->evtid);
 	if (WARN_ON_ONCE(!m))
 		return;
 
@@ -725,11 +725,11 @@ static void mbm_update_one_event(struct rdt_resource *r, struct rdt_l3_mon_domai
 
 	rr.r = r;
 	rr.hdr = &d->hdr;
-	rr.evtid = evtid;
+	rr.evt = &mon_event_all[evtid];
 	if (resctrl_arch_mbm_cntr_assign_enabled(r)) {
 		rr.is_mbm_cntr = true;
 	} else {
-		rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
+		rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, evtid);
 		if (IS_ERR(rr.arch_mon_ctx)) {
 			pr_warn_ratelimited("Failed to allocate monitor context: %ld",
 					    PTR_ERR(rr.arch_mon_ctx));
@@ -747,7 +747,7 @@ static void mbm_update_one_event(struct rdt_resource *r, struct rdt_l3_mon_domai
 		mbm_bw_count(rdtgrp, &rr);
 
 	if (rr.arch_mon_ctx)
-		resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
+		resctrl_arch_mon_ctx_free(rr.r, evtid, rr.arch_mon_ctx);
 }
 
 static void mbm_update(struct rdt_resource *r, struct rdt_l3_mon_domain *d,

fs/resctrl/rdtgroup.c

@@ -3103,7 +3103,7 @@ static struct mon_data *mon_get_kn_priv(enum resctrl_res_level rid, int domid,
 
 	list_for_each_entry(priv, &mon_data_kn_priv_list, list) {
 		if (priv->rid == rid && priv->domid == domid &&
-		    priv->sum == do_sum && priv->evtid == mevt->evtid)
+		    priv->sum == do_sum && priv->evt == mevt)
 			return priv;
 	}
 
@@ -3114,7 +3114,7 @@ static struct mon_data *mon_get_kn_priv(enum resctrl_res_level rid, int domid,
 	priv->rid = rid;
 	priv->domid = domid;
 	priv->sum = do_sum;
-	priv->evtid = mevt->evtid;
+	priv->evt = mevt;
 	list_add_tail(&priv->list, &mon_data_kn_priv_list);
 
 	return priv;
@@ -3281,7 +3281,7 @@ static int mon_add_all_files(struct kernfs_node *kn, struct rdt_domain_hdr *hdr,
 			return ret;
 
 		if (!do_sum && resctrl_is_mbm_event(mevt->evtid))
-			mon_event_read(&rr, r, hdr, prgrp, &hdr->cpu_mask, mevt->evtid, true);
+			mon_event_read(&rr, r, hdr, prgrp, &hdr->cpu_mask, mevt, true);
 	}
 
 	return 0;