[tip: x86/cache] x86/resctrl: Always initialise rid field in rdt_resources_all[]

["tip-bot2 for James Morse" <tip-bot2@linutronix.de>]

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

Commit-ID:     f6b25be204b8661e4c32fa770a4c9e3a113ee325
Gitweb:        https://git.kernel.org/tip/f6b25be204b8661e4c32fa770a4c9e3a113ee325
Author:        James Morse <james.morse@arm.com>
AuthorDate:    Thu, 15 May 2025 16:58:53 
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Fri, 16 May 2025 14:35:22 +02:00

x86/resctrl: Always initialise rid field in rdt_resources_all[]

x86 has an array, rdt_resources_all[], of all possible resources.
The for-each-resource walkers depend on the rid field of all
resources being initialised.

If the array ever grows due to another architecture adding a resource
type that is not defined on x86, the for-each-resources walkers will
loop forever.

Initialise all the rid values in resctrl_arch_late_init() before
any for-each-resource walker can be called.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/20250515165855.31452-24-james.morse@arm.com
---
 arch/x86/kernel/cpu/resctrl/core.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 58d7c6a..224bed2 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -60,7 +60,6 @@ struct rdt_hw_resource rdt_resources_all[RDT_NUM_RESOURCES] = {
 	[RDT_RESOURCE_L3] =
 	{
 		.r_resctrl = {
-			.rid			= RDT_RESOURCE_L3,
 			.name			= "L3",
 			.ctrl_scope		= RESCTRL_L3_CACHE,
 			.mon_scope		= RESCTRL_L3_CACHE,
@@ -74,7 +73,6 @@ struct rdt_hw_resource rdt_resources_all[RDT_NUM_RESOURCES] = {
 	[RDT_RESOURCE_L2] =
 	{
 		.r_resctrl = {
-			.rid			= RDT_RESOURCE_L2,
 			.name			= "L2",
 			.ctrl_scope		= RESCTRL_L2_CACHE,
 			.ctrl_domains		= ctrl_domain_init(RDT_RESOURCE_L2),
@@ -86,7 +84,6 @@ struct rdt_hw_resource rdt_resources_all[RDT_NUM_RESOURCES] = {
 	[RDT_RESOURCE_MBA] =
 	{
 		.r_resctrl = {
-			.rid			= RDT_RESOURCE_MBA,
 			.name			= "MB",
 			.ctrl_scope		= RESCTRL_L3_CACHE,
 			.ctrl_domains		= ctrl_domain_init(RDT_RESOURCE_MBA),
@@ -96,7 +93,6 @@ struct rdt_hw_resource rdt_resources_all[RDT_NUM_RESOURCES] = {
 	[RDT_RESOURCE_SMBA] =
 	{
 		.r_resctrl = {
-			.rid			= RDT_RESOURCE_SMBA,
 			.name			= "SMBA",
 			.ctrl_scope		= RESCTRL_L3_CACHE,
 			.ctrl_domains		= ctrl_domain_init(RDT_RESOURCE_SMBA),
@@ -996,7 +992,11 @@ void resctrl_cpu_detect(struct cpuinfo_x86 *c)
 static int __init resctrl_arch_late_init(void)
 {
 	struct rdt_resource *r;
-	int state, ret;
+	int state, ret, i;
+
+	/* for_each_rdt_resource() requires all rid to be initialised. */
+	for (i = 0; i < RDT_NUM_RESOURCES; i++)
+		rdt_resources_all[i].r_resctrl.rid = i;
 
 	/*
 	 * Initialize functions(or definitions) that are different