[PATCH v8 16/21] x86/resctrl: Always initialise rid field in rdt_resources_all[]

James Morse
2025-04-11T16:44:11Z

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>

---
Changes since v7:
* Split out of a previous patch due to a botched merged conflict.
---
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 58d7c6accdf2..ce684da600bc 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;
+
+ /* Initialise all rid values for_each_rdt_resource() */
+ for (i = 0; i < RDT_NUM_RESOURCES; i++)
+ rdt_resources_all[i].r_resctrl.rid = i;

/*
* Initialize functions(or definitions) that are different
--
2.20.1