[PATCH v11 06/23] arm,x86,fs/resctrl: Replace architecture resctrl_arch_{alloc,mon}_capable()

From: Tony Luck

Date: Mon Aug 31 2026 - 15:57:49 EST


All the information to determine whether a system is alloc, or mon,
capable is available to the file system. Architecture helpers are not
needed.

Define generic resctrl_alloc_capable() and resctrl_mon_capable() and
replace all architecture versions.

Suggested-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
v11:
New patch

include/linux/arm_mpam.h | 3 ---
include/linux/resctrl.h | 26 +++++++++++++++++++++++
arch/x86/include/asm/resctrl.h | 10 ---------
drivers/resctrl/mpam_resctrl.c | 26 ++---------------------
fs/resctrl/monitor.c | 10 ++++-----
fs/resctrl/pseudo_lock.c | 6 +++---
fs/resctrl/rdtgroup.c | 38 +++++++++++++++++-----------------
7 files changed, 55 insertions(+), 64 deletions(-)

diff --git a/include/linux/arm_mpam.h b/include/linux/arm_mpam.h
index f92a36187a52..ba4131048260 100644
--- a/include/linux/arm_mpam.h
+++ b/include/linux/arm_mpam.h
@@ -50,9 +50,6 @@ static inline int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx,
}
#endif

-bool resctrl_arch_alloc_capable(void);
-bool resctrl_arch_mon_capable(void);
-
void resctrl_arch_set_cpu_default_closid(int cpu, u32 closid);
void resctrl_arch_set_closid_rmid(struct task_struct *tsk, u32 closid, u32 rmid);
void resctrl_arch_set_cpu_default_closid_rmid(int cpu, u32 closid, u32 rmid);
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index dd09c2ce9a0f..4a6b0c1833d6 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -346,6 +346,32 @@ struct rdt_resource {
*/
struct rdt_resource *resctrl_arch_get_resource(enum resctrl_res_level l);

+/*
+ * resctrl_alloc_capable - Are any allocation resources enabled.
+ */
+static inline bool resctrl_alloc_capable(void)
+{
+ struct rdt_resource *r;
+
+ for_each_rdt_resource(r)
+ if ((r)->alloc_capable)
+ return true;
+ return false;
+}
+
+/*
+ * resctrl_mon_capable - Are any monitor resources enabled.
+ */
+static inline bool resctrl_mon_capable(void)
+{
+ struct rdt_resource *r;
+
+ for_each_rdt_resource(r)
+ if ((r)->mon_capable)
+ return true;
+ return false;
+}
+
/**
* struct resctrl_schema - configuration abilities of a resource presented to
* user-space
diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h
index ab7f6ccd149e..fb6cfff82e2f 100644
--- a/arch/x86/include/asm/resctrl.h
+++ b/arch/x86/include/asm/resctrl.h
@@ -50,11 +50,6 @@ DECLARE_STATIC_KEY_FALSE(rdt_enable_key);
DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);

-static inline bool resctrl_arch_alloc_capable(void)
-{
- return rdt_alloc_capable;
-}
-
static inline void resctrl_arch_enable_alloc(void)
{
static_branch_enable_cpuslocked(&rdt_alloc_enable_key);
@@ -67,11 +62,6 @@ static inline void resctrl_arch_disable_alloc(void)
static_branch_dec_cpuslocked(&rdt_enable_key);
}

-static inline bool resctrl_arch_mon_capable(void)
-{
- return rdt_mon_capable;
-}
-
static inline void resctrl_arch_enable_mon(void)
{
static_branch_enable_cpuslocked(&rdt_mon_enable_key);
diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index 9d223057953a..0db62dd2a71c 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -75,28 +75,6 @@ static DECLARE_WAIT_QUEUE_HEAD(wait_cacheinfo_ready);
*/
static bool resctrl_enabled;

-bool resctrl_arch_alloc_capable(void)
-{
- struct mpam_resctrl_res *res;
- enum resctrl_res_level rid;
-
- for_each_mpam_resctrl_control(res, rid) {
- if (res->resctrl_res.alloc_capable)
- return true;
- }
-
- return false;
-}
-
-bool resctrl_arch_mon_capable(void)
-{
- struct mpam_resctrl_res *res = &mpam_resctrl_controls[RDT_RESOURCE_L3];
- struct rdt_resource *l3 = &res->resctrl_res;
-
- /* All monitors are presented as being on the L3 cache */
- return l3->mon_capable;
-}
-
bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt)
{
return false;
@@ -1897,9 +1875,9 @@ int mpam_resctrl_setup(void)

cpus_read_unlock();

- if (!resctrl_arch_alloc_capable() && !resctrl_arch_mon_capable()) {
+ if (!resctrl_alloc_capable() && !resctrl_mon_capable()) {
pr_debug("No alloc(%u) or monitor(%u) found - resctrl not supported\n",
- resctrl_arch_alloc_capable(), resctrl_arch_mon_capable());
+ resctrl_alloc_capable(), resctrl_mon_capable());
return -EOPNOTSUPP;
}

diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
index 73413cb128ea..362737e13cd3 100644
--- a/fs/resctrl/monitor.c
+++ b/fs/resctrl/monitor.c
@@ -338,7 +338,7 @@ void free_rmid(u32 closid, u32 rmid)
* allows architectures that ignore the closid parameter to avoid an
* unnecessary check.
*/
- if (!resctrl_arch_mon_capable() ||
+ if (!resctrl_mon_capable() ||
idx == resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID,
RESCTRL_RESERVED_RMID))
return;
@@ -888,7 +888,7 @@ void mbm_handle_overflow(struct work_struct *work)
* If the filesystem has been unmounted this work no longer needs to
* run.
*/
- if (!resctrl_mounted || !resctrl_arch_mon_capable())
+ if (!resctrl_mounted || !resctrl_mon_capable())
goto out_unlock;

/*
@@ -950,7 +950,7 @@ void mbm_setup_overflow_handler(struct rdt_l3_mon_domain *dom, unsigned long del
* When a domain comes online there is no guarantee the filesystem is
* mounted. If not, there is no need to catch counter overflow.
*/
- if (!resctrl_mounted || !resctrl_arch_mon_capable())
+ if (!resctrl_mounted || !resctrl_mon_capable())
return;
cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu);
dom->mbm_work_cpu = cpu;
@@ -966,7 +966,7 @@ int setup_rmid_lru_list(void)
u32 idx;
int i;

- if (!resctrl_arch_mon_capable())
+ if (!resctrl_mon_capable())
return 0;

/*
@@ -1006,7 +1006,7 @@ int setup_rmid_lru_list(void)

void free_rmid_lru_list(void)
{
- if (!resctrl_arch_mon_capable())
+ if (!resctrl_mon_capable())
return;

mutex_lock(&rdtgroup_mutex);
diff --git a/fs/resctrl/pseudo_lock.c b/fs/resctrl/pseudo_lock.c
index dea2b4bf966f..04b69c0e37f2 100644
--- a/fs/resctrl/pseudo_lock.c
+++ b/fs/resctrl/pseudo_lock.c
@@ -383,7 +383,7 @@ static int rdtgroup_locksetup_user_restrict(struct rdtgroup *rdtgrp)
if (ret)
goto err_cpus;

- if (resctrl_arch_mon_capable()) {
+ if (resctrl_mon_capable()) {
ret = rdtgroup_kn_mode_restrict(rdtgrp, "mon_groups");
if (ret)
goto err_cpus_list;
@@ -430,7 +430,7 @@ static int rdtgroup_locksetup_user_restore(struct rdtgroup *rdtgrp)
if (ret)
goto err_cpus;

- if (resctrl_arch_mon_capable()) {
+ if (resctrl_mon_capable()) {
ret = rdtgroup_kn_mode_restore(rdtgrp, "mon_groups", 0777);
if (ret)
goto err_cpus_list;
@@ -577,7 +577,7 @@ int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp)
{
int ret;

- if (resctrl_arch_mon_capable()) {
+ if (resctrl_mon_capable()) {
ret = alloc_rmid(rdtgrp->closid);
if (ret < 0) {
rdt_last_cmd_puts("Out of RMIDs\n");
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 5dcbb0a964e8..79977200b1a0 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -685,13 +685,13 @@ static int __rdtgroup_move_task(struct task_struct *tsk,

static bool is_closid_match(struct task_struct *t, struct rdtgroup *r)
{
- return (resctrl_arch_alloc_capable() && (r->type == RDTCTRL_GROUP) &&
+ return (resctrl_alloc_capable() && (r->type == RDTCTRL_GROUP) &&
resctrl_arch_match_closid(t, r->closid));
}

static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r)
{
- return (resctrl_arch_mon_capable() && (r->type == RDTMON_GROUP) &&
+ return (resctrl_mon_capable() && (r->type == RDTMON_GROUP) &&
resctrl_arch_match_rmid(t, r->mon.parent->closid,
r->mon.rmid));
}
@@ -3159,9 +3159,9 @@ static void resctrl_unmount(void)
resctrl_arch_reset_all_ctrls(r);

resctrl_fs_teardown();
- if (resctrl_arch_alloc_capable())
+ if (resctrl_alloc_capable())
resctrl_arch_disable_alloc();
- if (resctrl_arch_mon_capable())
+ if (resctrl_mon_capable())
resctrl_arch_disable_mon();
resctrl_mounted = false;
mutex_unlock(&rdtgroup_mutex);
@@ -3215,7 +3215,7 @@ static int rdt_get_tree(struct fs_context *fc)
if (ret)
goto out_schemata_free;

- if (resctrl_arch_mon_capable())
+ if (resctrl_mon_capable())
flags |= RFTYPE_MON;

ret = rdtgroup_add_files(rdtgroup_default.kn, flags);
@@ -3228,7 +3228,7 @@ static int rdt_get_tree(struct fs_context *fc)
if (ret < 0)
goto out_closid_exit;

- if (resctrl_arch_mon_capable()) {
+ if (resctrl_mon_capable()) {
ret = mongroup_create_dir(rdtgroup_default.kn,
&rdtgroup_default, "mon_groups",
&kn_mongrp);
@@ -3248,12 +3248,12 @@ static int rdt_get_tree(struct fs_context *fc)
if (ret)
goto out_mondata;

- if (resctrl_arch_alloc_capable())
+ if (resctrl_alloc_capable())
resctrl_arch_enable_alloc();
- if (resctrl_arch_mon_capable())
+ if (resctrl_mon_capable())
resctrl_arch_enable_mon();

- if (resctrl_arch_alloc_capable() || resctrl_arch_mon_capable())
+ if (resctrl_alloc_capable() || resctrl_mon_capable())
resctrl_mounted = true;

if (resctrl_is_mbm_enabled()) {
@@ -3296,10 +3296,10 @@ static int rdt_get_tree(struct fs_context *fc)
return ret;

out_mondata:
- if (resctrl_arch_mon_capable())
+ if (resctrl_mon_capable())
kernfs_remove(kn_mondata);
out_mongrp:
- if (resctrl_arch_mon_capable()) {
+ if (resctrl_mon_capable()) {
mon_put_kn_priv();
rdtgroup_unassign_cntrs(&rdtgroup_default);
kernfs_remove(kn_mongrp);
@@ -3888,7 +3888,7 @@ static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp)
{
int ret;

- if (!resctrl_arch_mon_capable())
+ if (!resctrl_mon_capable())
return 0;

ret = alloc_rmid(rdtgrp->closid);
@@ -3913,7 +3913,7 @@ static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp)

static void mkdir_rdt_prepare_rmid_free(struct rdtgroup *rgrp)
{
- if (resctrl_arch_mon_capable()) {
+ if (resctrl_mon_capable()) {
rdtgroup_unassign_cntrs(rgrp);
free_rmid(rgrp->closid, rgrp->mon.rmid);
}
@@ -4004,7 +4004,7 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,

if (rtype == RDTCTRL_GROUP) {
files = RFTYPE_BASE | RFTYPE_CTRL;
- if (resctrl_arch_mon_capable())
+ if (resctrl_mon_capable())
files |= RFTYPE_MON;
} else {
files = RFTYPE_BASE | RFTYPE_MON;
@@ -4113,7 +4113,7 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,

list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);

- if (resctrl_arch_mon_capable()) {
+ if (resctrl_mon_capable()) {
/*
* Create an empty mon_groups directory to hold the subset
* of tasks and cpus to monitor.
@@ -4154,11 +4154,11 @@ static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
* allocation is supported, add a control and monitoring
* subdirectory
*/
- if (resctrl_arch_alloc_capable() && parent_kn == rdtgroup_default.kn)
+ if (resctrl_alloc_capable() && parent_kn == rdtgroup_default.kn)
return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode);

/* Else, attempt to add a monitoring subdirectory. */
- if (resctrl_arch_mon_capable())
+ if (resctrl_mon_capable())
return rdtgroup_mkdir_mon(parent_kn, name, mode);

return -EPERM;
@@ -4573,7 +4573,7 @@ void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_domain_hdr *h
* If resctrl is mounted, remove all the
* per domain monitor data directories.
*/
- if (resctrl_mounted && resctrl_arch_mon_capable())
+ if (resctrl_mounted && resctrl_mon_capable())
rmdir_mondata_subdir_allrdtgrp(r, hdr);

if (r->rid != RDT_RESOURCE_L3)
@@ -4710,7 +4710,7 @@ int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_domain_hdr *hdr
* by rdt_get_tree() calling mkdir_mondata_all().
* If resctrl is mounted, add per domain monitor data directories.
*/
- if (resctrl_mounted && resctrl_arch_mon_capable())
+ if (resctrl_mounted && resctrl_mon_capable())
mkdir_mondata_subdir_allrdtgrp(r, hdr);

out_unlock:
--
2.55.0