[PATCH v5 29/40] x86/resctrl: Claim get_{mon,ctrl}_domain_from_cpu() helpers for resctrl

From: James Morse
Date: Fri Oct 04 2024 - 14:11:52 EST


get_{mon,ctrl}_domain_from_cpu() are handy helpers that both the arch
code and resctrl need to use. Rename them to have a resctrl_ prefix
and move them to a header file.

Signed-off-by: James Morse <james.morse@xxxxxxx>
Tested-by: Carl Worth <carl@xxxxxxxxxxxxxxxxxxxxxx> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
Reviewed-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/resctrl/core.c | 30 ---------------------
arch/x86/kernel/cpu/resctrl/internal.h | 2 --
arch/x86/kernel/cpu/resctrl/monitor.c | 2 +-
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 +-
include/linux/resctrl.h | 37 ++++++++++++++++++++++++++
5 files changed, 39 insertions(+), 34 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 0da7314195af..f484726a2588 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -349,36 +349,6 @@ static void cat_wrmsr(struct msr_param *m)
wrmsrl(hw_res->msr_base + i, hw_dom->ctrl_val[i]);
}

-struct rdt_ctrl_domain *get_ctrl_domain_from_cpu(int cpu, struct rdt_resource *r)
-{
- struct rdt_ctrl_domain *d;
-
- lockdep_assert_cpus_held();
-
- list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
- /* Find the domain that contains this CPU */
- if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask))
- return d;
- }
-
- return NULL;
-}
-
-struct rdt_mon_domain *get_mon_domain_from_cpu(int cpu, struct rdt_resource *r)
-{
- struct rdt_mon_domain *d;
-
- lockdep_assert_cpus_held();
-
- list_for_each_entry(d, &r->mon_domains, hdr.list) {
- /* Find the domain that contains this CPU */
- if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask))
- return d;
- }
-
- return NULL;
-}
-
u32 resctrl_arch_get_num_closid(struct rdt_resource *r)
{
return resctrl_to_arch_res(r)->num_closid;
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 30de95e59129..e939a0a28a49 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -468,8 +468,6 @@ unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, struct rdt_ctrl_domain
unsigned long cbm);
enum rdtgrp_mode rdtgroup_mode_by_closid(int closid);
int rdtgroup_tasks_assigned(struct rdtgroup *r);
-struct rdt_ctrl_domain *get_ctrl_domain_from_cpu(int cpu, struct rdt_resource *r);
-struct rdt_mon_domain *get_mon_domain_from_cpu(int cpu, struct rdt_resource *r);
int closids_supported(void);
void closid_free(int closid);
int alloc_rmid(u32 closid);
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 175fd7dbf34f..39c450624ed0 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -767,7 +767,7 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm)
idx = resctrl_arch_rmid_idx_encode(closid, rmid);
pmbm_data = &dom_mbm->mbm_local[idx];

- dom_mba = get_ctrl_domain_from_cpu(smp_processor_id(), r_mba);
+ dom_mba = resctrl_get_ctrl_domain_from_cpu(smp_processor_id(), r_mba);
if (!dom_mba) {
pr_warn_once("Failure to get domain for MBA update\n");
return;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 596f5f087834..ee9c3e4ee889 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -4235,7 +4235,7 @@ void resctrl_offline_cpu(unsigned int cpu)
if (!l3->mon_capable)
goto out_unlock;

- d = get_mon_domain_from_cpu(cpu, l3);
+ d = resctrl_get_mon_domain_from_cpu(cpu, l3);
if (d) {
if (resctrl_is_mbm_enabled() && cpu == d->mbm_work_cpu) {
cancel_delayed_work(&d->mbm_over);
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 653d7cf41e64..bbce79190b13 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -3,6 +3,7 @@
#define _RESCTRL_H

#include <linux/cacheinfo.h>
+#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/pid.h>
@@ -397,6 +398,42 @@ static inline u32 resctrl_get_config_index(u32 closid,
}
}

+/*
+ * Caller must hold the cpuhp read lock to prevent the struct rdt_domain being
+ * freed.
+ */
+static inline struct rdt_ctrl_domain *
+resctrl_get_ctrl_domain_from_cpu(int cpu, struct rdt_resource *r)
+{
+ struct rdt_ctrl_domain *d;
+
+ lockdep_assert_cpus_held();
+
+ list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+ /* Find the domain that contains this CPU */
+ if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask))
+ return d;
+ }
+
+ return NULL;
+}
+
+static inline struct rdt_mon_domain *
+resctrl_get_mon_domain_from_cpu(int cpu, struct rdt_resource *r)
+{
+ struct rdt_mon_domain *d;
+
+ lockdep_assert_cpus_held();
+
+ list_for_each_entry(d, &r->mon_domains, hdr.list) {
+ /* Find the domain that contains this CPU */
+ if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask))
+ return d;
+ }
+
+ return NULL;
+}
+
/*
* Update the ctrl_val and apply this config right now.
* Must be called on one of the domain's CPUs.
--
2.39.2