[PATCH v7 18/49] x86/resctrl: Move the is_mbm_*_enabled() helpers to asm/resctrl.h

James Morse
2025-02-28T20:01:04Z

The architecture specific parts of resctrl provide helpers like
is_mbm_total_enabled() and is_mbm_local_enabled() to hide accesses
to the rdt_mon_features bitmap.

Exposing a group of helpers between the architecture and filesystem code
is preferable to a single unsigned-long like rdt_mon_features. Helpers
can be more readable and have a well defined behaviour, while allowing
architectures to hide more complex behaviour.

Once the filesystem parts of resctrl are moved, these existing helpers can
no longer live in internal.h. Move them to include/linux/resctrl.h
Once these are exposed to the wider kernel, they should have a
'resctrl_arch_' prefix, to fit the rest of the arch<->fs interface.

Move and rename the helpers that touch rdt_mon_features directly.
is_mbm_event() and is_mbm_enabled() are only called from rdtgroup.c,
so can be moved into that file.

Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
---
Chagnes since v6:
* Dropped a spurious check re-introduced by a bad rebase conflict.

Changes since v5:
* Removed the word 'export' due to its kernel-specific meaning.
* Reworded commit message.
---
arch/x86/include/asm/resctrl.h | 16 +++++++++
arch/x86/kernel/cpu/resctrl/core.c | 8 ++---
arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 4 +--
arch/x86/kernel/cpu/resctrl/internal.h | 27 ---------------
arch/x86/kernel/cpu/resctrl/monitor.c | 16 ++++-----
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 40 +++++++++++++++--------
6 files changed, 56 insertions(+), 55 deletions(-)

diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h
index 52f2326e2b1e..6d4c7ea2c9e3 100644
--- a/arch/x86/include/asm/resctrl.h
+++ b/arch/x86/include/asm/resctrl.h
@@ -42,6 +42,7 @@ DECLARE_PER_CPU(struct resctrl_pqr_state, pqr_state);

extern bool rdt_alloc_capable;
extern bool rdt_mon_capable;
+extern unsigned int rdt_mon_features;

DECLARE_STATIC_KEY_FALSE(rdt_enable_key);
DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
@@ -81,6 +82,21 @@ static inline void resctrl_arch_disable_mon(void)
static_branch_dec_cpuslocked(&rdt_enable_key);
}

+static inline bool resctrl_arch_is_llc_occupancy_enabled(void)
+{
+ return (rdt_mon_features & (1 << QOS_L3_OCCUP_EVENT_ID));
+}
+
+static inline bool resctrl_arch_is_mbm_total_enabled(void)
+{
+ return (rdt_mon_features & (1 << QOS_L3_MBM_TOTAL_EVENT_ID));
+}
+
+static inline bool resctrl_arch_is_mbm_local_enabled(void)
+{
+ return (rdt_mon_features & (1 << QOS_L3_MBM_LOCAL_EVENT_ID));
+}
+
/*
* __resctrl_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR
*
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index d04d65754491..5464dc1611e9 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -455,13 +455,13 @@ static int arch_domain_mbm_alloc(u32 num_rmid, struct rdt_hw_mon_domain *hw_dom)
{
size_t tsize;

- if (is_mbm_total_enabled()) {
+ if (resctrl_arch_is_mbm_total_enabled()) {
tsize = sizeof(*hw_dom->arch_mbm_total);
hw_dom->arch_mbm_total = kcalloc(num_rmid, tsize, GFP_KERNEL);
if (!hw_dom->arch_mbm_total)
return -ENOMEM;
}
- if (is_mbm_local_enabled()) {
+ if (resctrl_arch_is_mbm_local_enabled()) {
tsize = sizeof(*hw_dom->arch_mbm_local);
hw_dom->arch_mbm_local = kcalloc(num_rmid, tsize, GFP_KERNEL);
if (!hw_dom->arch_mbm_local) {
@@ -910,9 +910,9 @@ static __init bool get_rdt_mon_resources(void)
if (!rdt_mon_features)
return false;

- if (is_mbm_local_enabled())
+ if (resctrl_arch_is_mbm_local_enabled())
mba_mbps_default_event = QOS_L3_MBM_LOCAL_EVENT_ID;
- else if (is_mbm_total_enabled())
+ else if (resctrl_arch_is_mbm_total_enabled())
mba_mbps_default_event = QOS_L3_MBM_TOTAL_EVENT_ID;

return !rdt_get_mon_l3_config(r);
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index 763317ea2256..1ecc93282b7d 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -559,12 +559,12 @@ ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of,
rdt_last_cmd_clear();

if (!strcmp(buf, "mbm_local_bytes")) {
- if (is_mbm_local_enabled())
+ if (resctrl_arch_is_mbm_local_enabled())
rdtgrp->mba_mbps_event = QOS_L3_MBM_LOCAL_EVENT_ID;
else
ret = -EINVAL;
} else if (!strcmp(buf, "mbm_total_bytes")) {
- if (is_mbm_total_enabled())
+ if (resctrl_arch_is_mbm_total_enabled())
rdtgrp->mba_mbps_event = QOS_L3_MBM_TOTAL_EVENT_ID;
else
ret = -EINVAL;
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 82dbc1606663..4a5996d1e060 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -156,7 +156,6 @@ struct rmid_read {
void *arch_mon_ctx;
};

-extern unsigned int rdt_mon_features;
extern struct list_head resctrl_schema_all;
extern bool resctrl_mounted;

@@ -406,32 +405,6 @@ struct msr_param {
u32 high;
};

-static inline bool is_llc_occupancy_enabled(void)
-{
- return (rdt_mon_features & (1 << QOS_L3_OCCUP_EVENT_ID));
-}
-
-static inline bool is_mbm_total_enabled(void)
-{
- return (rdt_mon_features & (1 << QOS_L3_MBM_TOTAL_EVENT_ID));
-}
-
-static inline bool is_mbm_local_enabled(void)
-{
- return (rdt_mon_features & (1 << QOS_L3_MBM_LOCAL_EVENT_ID));
-}
-
-static inline bool is_mbm_enabled(void)
-{
- return (is_mbm_total_enabled() || is_mbm_local_enabled());
-}
-
-static inline bool is_mbm_event(int e)
-{
- return (e >= QOS_L3_MBM_TOTAL_EVENT_ID &&
- e <= QOS_L3_MBM_LOCAL_EVENT_ID);
-}
-
/**
* struct rdt_hw_resource - arch private attributes of a resctrl resource
* @r_resctrl: Attributes of the resource used directly by resctrl.
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 1730ba814834..d883ed56ec90 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -295,11 +295,11 @@ void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_mon_domain *
{
struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d);

- if (is_mbm_total_enabled())
+ if (resctrl_arch_is_mbm_total_enabled())
memset(hw_dom->arch_mbm_total, 0,
sizeof(*hw_dom->arch_mbm_total) * r->num_rmid);

- if (is_mbm_local_enabled())
+ if (resctrl_arch_is_mbm_local_enabled())
memset(hw_dom->arch_mbm_local, 0,
sizeof(*hw_dom->arch_mbm_local) * r->num_rmid);
}
@@ -569,7 +569,7 @@ void free_rmid(u32 closid, u32 rmid)

entry = __rmid_entry(idx);

- if (is_llc_occupancy_enabled())
+ if (resctrl_arch_is_llc_occupancy_enabled())
add_rmid_to_limbo(entry);
else
list_add_tail(&entry->list, &rmid_free_lru);
@@ -852,10 +852,10 @@ static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d,
* This is protected from concurrent reads from user as both
* the user and overflow handler hold the global mutex.
*/
- if (is_mbm_total_enabled())
+ if (resctrl_arch_is_mbm_total_enabled())
mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_TOTAL_EVENT_ID);

- if (is_mbm_local_enabled())
+ if (resctrl_arch_is_mbm_local_enabled())
mbm_update_one_event(r, d, closid, rmid, QOS_L3_MBM_LOCAL_EVENT_ID);
}

@@ -1085,11 +1085,11 @@ static void l3_mon_evt_init(struct rdt_resource *r)
{
INIT_LIST_HEAD(&r->evt_list);

- if (is_llc_occupancy_enabled())
+ if (resctrl_arch_is_llc_occupancy_enabled())
list_add_tail(&llc_occupancy_event.list, &r->evt_list);
- if (is_mbm_total_enabled())
+ if (resctrl_arch_is_mbm_total_enabled())
list_add_tail(&mbm_total_event.list, &r->evt_list);
- if (is_mbm_local_enabled())
+ if (resctrl_arch_is_mbm_local_enabled())
list_add_tail(&mbm_local_event.list, &r->evt_list);
}

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index badac3f5da72..eb32fbc3abea 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -117,6 +117,18 @@ void rdt_staged_configs_clear(void)
}
}

+static bool resctrl_is_mbm_enabled(void)
+{
+ return (resctrl_arch_is_mbm_total_enabled() ||
+ resctrl_arch_is_mbm_local_enabled());
+}
+
+static bool resctrl_is_mbm_event(int e)
+{
+ return (e >= QOS_L3_MBM_TOTAL_EVENT_ID &&
+ e <= QOS_L3_MBM_LOCAL_EVENT_ID);
+}
+
/*
* Trivial allocator for CLOSIDs. Since h/w only supports a small number,
* we can keep a bitmap of free CLOSIDs in a single integer.
@@ -164,7 +176,7 @@ static int closid_alloc(void)
lockdep_assert_held(&rdtgroup_mutex);

if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID) &&
- is_llc_occupancy_enabled()) {
+ resctrl_arch_is_llc_occupancy_enabled()) {
cleanest_closid = resctrl_find_cleanest_closid();
if (cleanest_closid < 0)
return cleanest_closid;
@@ -2378,7 +2390,7 @@ static bool supports_mba_mbps(void)
struct rdt_resource *rmbm = resctrl_arch_get_resource(RDT_RESOURCE_L3);
struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);

- return (is_mbm_enabled() &&
+ return (resctrl_is_mbm_enabled() &&
r->alloc_capable && is_mba_linear() &&
r->ctrl_scope == rmbm->mon_scope);
}
@@ -2756,7 +2768,7 @@ static int rdt_get_tree(struct fs_context *fc)
if (resctrl_arch_alloc_capable() || resctrl_arch_mon_capable())
resctrl_mounted = true;

- if (is_mbm_enabled()) {
+ if (resctrl_is_mbm_enabled()) {
r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
list_for_each_entry(dom, &r->mon_domains, hdr.list)
mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL,
@@ -3125,7 +3137,7 @@ static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d,
if (ret)
return ret;

- if (!do_sum && is_mbm_event(mevt->evtid))
+ if (!do_sum && resctrl_is_mbm_event(mevt->evtid))
mon_event_read(&rr, r, d, prgrp, &d->hdr.cpu_mask, mevt->evtid, true);
}

@@ -4082,9 +4094,9 @@ void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d
if (resctrl_mounted && resctrl_arch_mon_capable())
rmdir_mondata_subdir_allrdtgrp(r, d);

- if (is_mbm_enabled())
+ if (resctrl_is_mbm_enabled())
cancel_delayed_work(&d->mbm_over);
- if (is_llc_occupancy_enabled() && has_busy_rmid(d)) {
+ if (resctrl_arch_is_llc_occupancy_enabled() && has_busy_rmid(d)) {
/*
* When a package is going down, forcefully
* decrement rmid->ebusy. There is no way to know
@@ -4120,12 +4132,12 @@ static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_mon_domain
u32 idx_limit = resctrl_arch_system_num_rmid_idx();
size_t tsize;

- if (is_llc_occupancy_enabled()) {
+ if (resctrl_arch_is_llc_occupancy_enabled()) {
d->rmid_busy_llc = bitmap_zalloc(idx_limit, GFP_KERNEL);
if (!d->rmid_busy_llc)
return -ENOMEM;
}
- if (is_mbm_total_enabled()) {
+ if (resctrl_arch_is_mbm_total_enabled()) {
tsize = sizeof(*d->mbm_total);
d->mbm_total = kcalloc(idx_limit, tsize, GFP_KERNEL);
if (!d->mbm_total) {
@@ -4133,7 +4145,7 @@ static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_mon_domain
return -ENOMEM;
}
}
- if (is_mbm_local_enabled()) {
+ if (resctrl_arch_is_mbm_local_enabled()) {
tsize = sizeof(*d->mbm_local);
d->mbm_local = kcalloc(idx_limit, tsize, GFP_KERNEL);
if (!d->mbm_local) {
@@ -4172,13 +4184,13 @@ int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)
if (err)
goto out_unlock;

- if (is_mbm_enabled()) {
+ if (resctrl_is_mbm_enabled()) {
INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow);
mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL,
RESCTRL_PICK_ANY_CPU);
}

- if (is_llc_occupancy_enabled())
+ if (resctrl_arch_is_llc_occupancy_enabled())
INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo);

/*
@@ -4233,12 +4245,12 @@ void resctrl_offline_cpu(unsigned int cpu)

d = get_mon_domain_from_cpu(cpu, l3);
if (d) {
- if (is_mbm_enabled() && cpu == d->mbm_work_cpu) {
+ if (resctrl_is_mbm_enabled() && cpu == d->mbm_work_cpu) {
cancel_delayed_work(&d->mbm_over);
mbm_setup_overflow_handler(d, 0, cpu);
}
- if (is_llc_occupancy_enabled() && cpu == d->cqm_work_cpu &&
- has_busy_rmid(d)) {
+ if (resctrl_arch_is_llc_occupancy_enabled() &&
+ cpu == d->cqm_work_cpu && has_busy_rmid(d)) {
cancel_delayed_work(&d->cqm_limbo);
cqm_setup_limbo_handler(d, 0, cpu);
}
--
2.39.5