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 | 125 +++++++++++++++++++++++++-------------------
1 file changed, 70 insertions(+), 55 deletions(-)
diff --git a/arch/x86/events/amd/iommu.c b/arch/x86/events/amd/iommu.c
index 5cc7c14..a1d12f4 100644
--- a/arch/x86/events/amd/iommu.c
+++ b/arch/x86/events/amd/iommu.c
@@ -34,16 +34,21 @@
#define GET_DOMID_MASK(c) ((c >> 16) & 0xFFFFULL)
#define GET_PASID_MASK(c) ((c >> 32) & 0xFFFFFULL)
-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
*---------------------------------------------*/
@@ -206,8 +211,6 @@ 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)
@@ -229,18 +232,6 @@ 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->iommu_csource = GET_CSOURCE(event->attr.config);
hwc->iommu_devid = GET_DEVID(event->attr.config);
@@ -253,9 +244,14 @@ static int perf_iommu_event_init(struct perf_event *event)
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);
struct hw_perf_event *hwc = &ev->hw;
u8 bank = hwc->iommu_bank;
u8 cntr = hwc->iommu_cntr;
@@ -285,7 +281,7 @@ 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);
struct hw_perf_event *hwc = &event->hw;
u64 reg = 0ULL;
@@ -305,7 +301,7 @@ static void perf_iommu_start(struct perf_event *event, int
flags)
if (flags & PERF_EF_RELOAD) {
u64 prev_raw_count = local64_read(&hwc->prev_count);
- struct amd_iommu *iommu = get_amd_iommu(0);
+ struct amd_iommu *iommu = perf_event_2_iommu(event);
amd_iommu_pc_set_reg(iommu, hwc->iommu_bank, hwc->iommu_cntr,
IOMMU_PC_COUNTER_REG, &prev_raw_count);
@@ -320,7 +316,7 @@ 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, hwc->iommu_bank, hwc->iommu_cntr,
IOMMU_PC_COUNTER_REG, &count))
@@ -408,11 +404,6 @@ 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,
@@ -420,47 +411,56 @@ 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("Detected AMD IOMMU (%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())
@@ -470,11 +470,26 @@ 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
