[tip: x86/cache] x86/resctrl: Walk the resctrl schema list instead of an arch list

[tip-bot2 for James Morse]

The following commit has been merged into the x86/cache branch of tip:

Commit-ID:     331ebe4c43496cdc7f8d9a32d4ef59300b748435
Gitweb:        https://git.kernel.org/tip/331ebe4c43496cdc7f8d9a32d4ef59300b748435
Author:        James Morse <james.morse@xxxxxxx>
AuthorDate:    Wed, 28 Jul 2021 17:06:19 
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Wed, 11 Aug 2021 13:20:43 +02:00

x86/resctrl: Walk the resctrl schema list instead of an arch list

When parsing a schema configuration value from user-space, resctrl walks
the architectures rdt_resources_all[] array to find a matching struct
rdt_resource.

Once the CDP resources are merged there will be one resource in use
by two schemata. Anything walking rdt_resources_all[] on behalf of a
user-space request should walk the list of struct resctrl_schema
instead.

Change the users of for_each_alloc_enabled_rdt_resource() to walk the
schema instead. Schemata were only created for alloc_enabled resources
so these two lists are currently equivalent.

schemata_list_create() and rdt_kill_sb() are ignored. The first
creates the schema list, and will eventually loop over the resource
indexes using an arch helper to retrieve the resource. rdt_kill_sb()
will eventually make use of an arch 'reset everything' helper.

After the filesystem code is moved, rdtgroup_pseudo_locked_in_hierarchy()
remains part of the x86 specific hooks to support pseudo lock. This
code walks each domain, and still does this after the separate resources
are merged.

Signed-off-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Jamie Iles <jamie@xxxxxxxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Tested-by: Babu Moger <babu.moger@xxxxxxx>
Link: https://lkml.kernel.org/r/20210728170637.25610-7-james.morse@xxxxxxx
---
 arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 23 ++++++++++++++--------
 arch/x86/kernel/cpu/resctrl/rdtgroup.c    | 18 +++++++++++------
 2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index 08eef53..405b99d 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -287,10 +287,12 @@ static int rdtgroup_parse_resource(char *resname, char *tok,
 				   struct rdtgroup *rdtgrp)
 {
 	struct rdt_hw_resource *hw_res;
+	struct resctrl_schema *s;
 	struct rdt_resource *r;
 
-	for_each_alloc_enabled_rdt_resource(r) {
-		hw_res = resctrl_to_arch_res(r);
+	list_for_each_entry(s, &resctrl_schema_all, list) {
+		r = s->res;
+		hw_res = resctrl_to_arch_res(s->res);
 		if (!strcmp(resname, r->name) && rdtgrp->closid < hw_res->num_closid)
 			return parse_line(tok, r, rdtgrp);
 	}
@@ -301,6 +303,7 @@ static int rdtgroup_parse_resource(char *resname, char *tok,
 ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
 				char *buf, size_t nbytes, loff_t off)
 {
+	struct resctrl_schema *s;
 	struct rdtgroup *rdtgrp;
 	struct rdt_domain *dom;
 	struct rdt_resource *r;
@@ -331,8 +334,8 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
 		goto out;
 	}
 
-	for_each_alloc_enabled_rdt_resource(r) {
-		list_for_each_entry(dom, &r->domains, list)
+	list_for_each_entry(s, &resctrl_schema_all, list) {
+		list_for_each_entry(dom, &s->res->domains, list)
 			dom->have_new_ctrl = false;
 	}
 
@@ -353,7 +356,8 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
 			goto out;
 	}
 
-	for_each_alloc_enabled_rdt_resource(r) {
+	list_for_each_entry(s, &resctrl_schema_all, list) {
+		r = s->res;
 		ret = update_domains(r, rdtgrp->closid);
 		if (ret)
 			goto out;
@@ -401,6 +405,7 @@ int rdtgroup_schemata_show(struct kernfs_open_file *of,
 			   struct seq_file *s, void *v)
 {
 	struct rdt_hw_resource *hw_res;
+	struct resctrl_schema *schema;
 	struct rdtgroup *rdtgrp;
 	struct rdt_resource *r;
 	int ret = 0;
@@ -409,8 +414,10 @@ int rdtgroup_schemata_show(struct kernfs_open_file *of,
 	rdtgrp = rdtgroup_kn_lock_live(of->kn);
 	if (rdtgrp) {
 		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
-			for_each_alloc_enabled_rdt_resource(r)
+			list_for_each_entry(schema, &resctrl_schema_all, list) {
+				r = schema->res;
 				seq_printf(s, "%s:uninitialized\n", r->name);
+			}
 		} else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
 			if (!rdtgrp->plr->d) {
 				rdt_last_cmd_clear();
@@ -424,8 +431,8 @@ int rdtgroup_schemata_show(struct kernfs_open_file *of,
 			}
 		} else {
 			closid = rdtgrp->closid;
-			for_each_alloc_enabled_rdt_resource(r) {
-				hw_res = resctrl_to_arch_res(r);
+			list_for_each_entry(schema, &resctrl_schema_all, list) {
+				hw_res = resctrl_to_arch_res(schema->res);
 				if (closid < hw_res->num_closid)
 					show_doms(s, r, closid);
 			}
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index d7fd071..7502b7d 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -104,12 +104,12 @@ int closids_supported(void)
 static void closid_init(void)
 {
 	struct rdt_hw_resource *hw_res;
-	struct rdt_resource *r;
+	struct resctrl_schema *s;
 	int rdt_min_closid = 32;
 
 	/* Compute rdt_min_closid across all resources */
-	for_each_alloc_enabled_rdt_resource(r) {
-		hw_res = resctrl_to_arch_res(r);
+	list_for_each_entry(s, &resctrl_schema_all, list) {
+		hw_res = resctrl_to_arch_res(s->res);
 		rdt_min_closid = min(rdt_min_closid, hw_res->num_closid);
 	}
 
@@ -1276,11 +1276,13 @@ static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
 {
 	struct rdt_hw_domain *hw_dom;
 	int closid = rdtgrp->closid;
+	struct resctrl_schema *s;
 	struct rdt_resource *r;
 	bool has_cache = false;
 	struct rdt_domain *d;
 
-	for_each_alloc_enabled_rdt_resource(r) {
+	list_for_each_entry(s, &resctrl_schema_all, list) {
+		r = s->res;
 		if (r->rid == RDT_RESOURCE_MBA)
 			continue;
 		has_cache = true;
@@ -1418,6 +1420,7 @@ unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
 static int rdtgroup_size_show(struct kernfs_open_file *of,
 			      struct seq_file *s, void *v)
 {
+	struct resctrl_schema *schema;
 	struct rdt_hw_domain *hw_dom;
 	struct rdtgroup *rdtgrp;
 	struct rdt_resource *r;
@@ -1449,7 +1452,8 @@ static int rdtgroup_size_show(struct kernfs_open_file *of,
 		goto out;
 	}
 
-	for_each_alloc_enabled_rdt_resource(r) {
+	list_for_each_entry(schema, &resctrl_schema_all, list) {
+		r = schema->res;
 		sep = false;
 		seq_printf(s, "%*s:", max_name_width, r->name);
 		list_for_each_entry(d, &r->domains, list) {
@@ -2815,10 +2819,12 @@ static void rdtgroup_init_mba(struct rdt_resource *r)
 /* Initialize the RDT group's allocations. */
 static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
 {
+	struct resctrl_schema *s;
 	struct rdt_resource *r;
 	int ret;
 
-	for_each_alloc_enabled_rdt_resource(r) {
+	list_for_each_entry(s, &resctrl_schema_all, list) {
+		r = s->res;
 		if (r->rid == RDT_RESOURCE_MBA) {
 			rdtgroup_init_mba(r);
 		} else {