From: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
Add multi-IOMMU support for perf by exposing an AMD IOMMU PMU
for each IOMMU found in the system via:
/bus/event_source/devices/amd_iommu_x
where x is the IOMMU index. This allows users to specify
different events to be programmed onto performance counters
of each IOMMU.
Cc: Borislav Petkov <b...@alien8.de>
Cc: Peter Zijlstra <pet...@infradead.org>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
---
arch/x86/events/amd/iommu.c | 129 ++++++++++++++++++++++++--------------------
1 file changed, 72 insertions(+), 57 deletions(-)
diff --git a/arch/x86/events/amd/iommu.c b/arch/x86/events/amd/iommu.c
index 7bbf405..cc1d2eb 100644
--- a/arch/x86/events/amd/iommu.c
+++ b/arch/x86/events/amd/iommu.c
@@ -35,16 +35,21 @@
#define _GET_PASID_MASK(ev) ((ev->hw.extra_reg.config >> 16) & 0xFFFFULL)
#define _GET_DOMID_MASK(ev) ((ev->hw.extra_reg.config >> 32) & 0xFFFFULL)
-static struct perf_amd_iommu __perf_iommu;
+#define PERF_AMD_IOMMU_NAME_SIZE 16
struct perf_amd_iommu {
+ struct list_head list;
struct pmu pmu;
+ struct amd_iommu *iommu;
+ char name[PERF_AMD_IOMMU_NAME_SIZE];
u8 max_banks;
u8 max_counters;
u64 cntr_assign_mask;
raw_spinlock_t lock;
};
+static LIST_HEAD(perf_amd_iommu_list);
+
/*---------------------------------------------
* sysfs format attributes
*---------------------------------------------*/
@@ -202,8 +207,6 @@ static int clear_avail_iommu_bnk_cntr(struct perf_amd_iommu
*perf_iommu,
static int perf_iommu_event_init(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
- struct perf_amd_iommu *perf_iommu;
- u64 config, config1;
/* test the event attr type check for PMU enumeration */
if (event->attr.type != event->pmu->type)
@@ -225,28 +228,21 @@ static int perf_iommu_event_init(struct perf_event *event)
if (event->cpu < 0)
return -EINVAL;
- perf_iommu = &__perf_iommu;
-
- if (event->pmu != &perf_iommu->pmu)
- return -ENOENT;
-
- if (perf_iommu) {
- config = event->attr.config;
- config1 = event->attr.config1;
- } else {
- return -EINVAL;
- }
-
/* update the hw_perf_event struct with the iommu config data */
- hwc->config = config;
- hwc->extra_reg.config = config1;
+ hwc->config = event->attr.config;
+ hwc->extra_reg.config = event->attr.config1;
return 0;
}
+static inline struct amd_iommu *perf_event_2_iommu(struct perf_event *ev)
+{
+ return (container_of(ev->pmu, struct perf_amd_iommu, pmu))->iommu;
+}
+
static void perf_iommu_enable_event(struct perf_event *ev)
{
- struct amd_iommu *iommu = get_amd_iommu(0);
+ struct amd_iommu *iommu = perf_event_2_iommu(ev);
u8 csource = _GET_CSOURCE(ev);
u16 devid = _GET_DEVID(ev);
u8 bank = _GET_BANK(ev);
@@ -274,7 +270,7 @@ static void perf_iommu_enable_event(struct perf_event *ev)
static void perf_iommu_disable_event(struct perf_event *event)
{
- struct amd_iommu *iommu = get_amd_iommu(0);
+ struct amd_iommu *iommu = perf_event_2_iommu(event);
u64 reg = 0ULL;
amd_iommu_pc_set_reg(iommu, _GET_BANK(event), _GET_CNTR(event),
@@ -284,7 +280,7 @@ static void perf_iommu_disable_event(struct perf_event
*event)
static void perf_iommu_start(struct perf_event *event, int flags)
{
struct hw_perf_event *hwc = &event->hw;
- struct amd_iommu *iommu = get_amd_iommu(0);
+ struct amd_iommu *iommu = perf_event_2_iommu(event);
if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
return;
@@ -307,7 +303,7 @@ static void perf_iommu_read(struct perf_event *event)
{
u64 count, prev, delta;
struct hw_perf_event *hwc = &event->hw;
- struct amd_iommu *iommu = get_amd_iommu(0);
+ struct amd_iommu *iommu = perf_event_2_iommu(event);
if (amd_iommu_pc_get_reg(iommu, _GET_BANK(event), _GET_CNTR(event),
IOMMU_PC_COUNTER_REG, &count))
@@ -401,11 +397,6 @@ static __init int _init_events_attrs(void)
return 0;
}
-static __init void amd_iommu_pc_exit(void)
-{
- kfree(amd_iommu_events_group.attrs);
-}
-
const struct attribute_group *amd_iommu_attr_groups[] = {
&amd_iommu_format_group,
&amd_iommu_cpumask_group,
@@ -413,47 +404,56 @@ static __init void amd_iommu_pc_exit(void)
NULL,
};
+static struct pmu iommu_pmu = {
+ .event_init = perf_iommu_event_init,
+ .add = perf_iommu_add,
+ .del = perf_iommu_del,
+ .start = perf_iommu_start,
+ .stop = perf_iommu_stop,
+ .read = perf_iommu_read,
+ .task_ctx_nr = perf_invalid_context,
+ .attr_groups = amd_iommu_attr_groups,
+};
+
static __init int
-_init_perf_amd_iommu(struct perf_amd_iommu *perf_iommu, char *name)
+init_one_iommu(unsigned int idx)
{
int ret;
+ struct perf_amd_iommu *perf_iommu;
- raw_spin_lock_init(&perf_iommu->lock);
+ perf_iommu = kzalloc(sizeof(struct perf_amd_iommu), GFP_KERNEL);
+ if (!perf_iommu)
+ return -ENOMEM;
- /* Init cpumask attributes to only core 0 */
- cpumask_set_cpu(0, &iommu_cpumask);
+ raw_spin_lock_init(&perf_iommu->lock);
- perf_iommu->max_banks = amd_iommu_pc_get_max_banks(0);
- perf_iommu->max_counters = amd_iommu_pc_get_max_counters(0);
- if (!perf_iommu->max_banks || !perf_iommu->max_counters)
+ perf_iommu->pmu = iommu_pmu;
+ perf_iommu->iommu = get_amd_iommu(idx);
+ perf_iommu->max_banks = amd_iommu_pc_get_max_banks(idx);
+ perf_iommu->max_counters = amd_iommu_pc_get_max_counters(idx);
+ if (!perf_iommu->iommu || !perf_iommu->max_banks ||
+ !perf_iommu->max_counters) {
+ kfree(perf_iommu);
return -EINVAL;
+ }
- perf_iommu->pmu.attr_groups = amd_iommu_attr_groups;
- ret = perf_pmu_register(&perf_iommu->pmu, name, -1);
- if (ret)
- pr_err("Error initializing AMD IOMMU perf counters.\n");
- else
- pr_info("perf: amd_iommu: Detected. (%d banks, %d
counters/bank)\n",
- amd_iommu_pc_get_max_banks(0),
- amd_iommu_pc_get_max_counters(0));
+ snprintf(perf_iommu->name, PERF_AMD_IOMMU_NAME_SIZE, "amd_iommu_%u",
idx);
+ ret = perf_pmu_register(&perf_iommu->pmu, perf_iommu->name, -1);
+ if (!ret) {
+ pr_info("Detected AMD IOMMU #%d (%d banks, %d counters/bank)\n",
+ idx, perf_iommu->max_banks, perf_iommu->max_counters);
+ list_add_tail(&perf_iommu->list, &perf_amd_iommu_list);
+ } else {
+ pr_warn("Error initializing IOMMU %d.\n", idx);
+ kfree(perf_iommu);
+ }
return ret;
}
-static struct perf_amd_iommu __perf_iommu = {
- .pmu = {
- .task_ctx_nr = perf_invalid_context,
- .event_init = perf_iommu_event_init,
- .add = perf_iommu_add,
- .del = perf_iommu_del,
- .start = perf_iommu_start,
- .stop = perf_iommu_stop,
- .read = perf_iommu_read,
- },
-};
-
static __init int amd_iommu_pc_init(void)
{
int ret;
+ unsigned int i, cnt = 0;
/* Make sure the IOMMU PC resource is available */
if (!amd_iommu_pc_supported())
@@ -463,11 +463,26 @@ static __init int amd_iommu_pc_init(void)
if (ret)
return ret;
- ret = _init_perf_amd_iommu(&__perf_iommu, "amd_iommu");
- if (ret)
- amd_iommu_pc_exit();
+ /*
+ * An IOMMU PMU is specific to each IOMMU, and can
+ * function independently. So, we go through all IOMMUs
+ * and ignore the one that fails initialization unless
+ * all IOMMU are failing.
+ */
+ for (i = 0; i < amd_iommu_get_num_iommus(); i++) {
+ ret = init_one_iommu(i);
+ if (!ret)
+ cnt++;
+ }
- return ret;
+ if (!cnt) {
+ kfree(amd_iommu_events_group.attrs);
+ return -ENODEV;
+ }
+
+ /* Init cpumask attributes to only core 0 */
+ cpumask_set_cpu(0, &iommu_cpumask);
+ return 0;
}
device_initcall(amd_iommu_pc_init);
--
1.8.3.1
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