[PATCH v12 09/10] perf/amd/iommu: Introduce amd_iommu-specific struct in struct hw_perf_event

From: Suravee Suthikulpanit
Date: Wed Mar 22 2017 - 03:05:52 EST

From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>

Current AMD IOMMU Perf PMU inappropriately uses hardware struct
inside the union inside the struct hw_perf_event, mainly the use of
extra_reg.

Instead, introduce amd_iommu-specific struct with required
parameters to be programmed onto the IOMMU performance counter
control register.

Also update the pasid field from 16 to 20 bits.

Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
arch/x86/events/amd/iommu.c | 102 +++++++++++++++++++-------------------------
include/linux/perf_event.h | 7 +++
2 files changed, 52 insertions(+), 57 deletions(-)

diff --git a/arch/x86/events/amd/iommu.c b/arch/x86/events/amd/iommu.c
index 7ac8138..915a20c 100644
--- a/arch/x86/events/amd/iommu.c
+++ b/arch/x86/events/amd/iommu.c
@@ -23,17 +23,16 @@

#define COUNTER_SHIFT 16

-#define _GET_BANK(ev) ((u8)(ev->hw.extra_reg.reg >> 8))
-#define _GET_CNTR(ev) ((u8)(ev->hw.extra_reg.reg))
-
-/* iommu pmu config masks */
-#define _GET_CSOURCE(ev) ((ev->hw.config & 0xFFULL))
-#define _GET_DEVID(ev) ((ev->hw.config >> 8) & 0xFFFFULL)
-#define _GET_PASID(ev) ((ev->hw.config >> 24) & 0xFFFFULL)
-#define _GET_DOMID(ev) ((ev->hw.config >> 40) & 0xFFFFULL)
-#define _GET_DEVID_MASK(ev) ((ev->hw.extra_reg.config) & 0xFFFFULL)
-#define _GET_PASID_MASK(ev) ((ev->hw.extra_reg.config >> 16) & 0xFFFFULL)
-#define _GET_DOMID_MASK(ev) ((ev->hw.extra_reg.config >> 32) & 0xFFFFULL)
+/* iommu pmu conf masks */
+#define GET_CSOURCE(x) (x->conf & 0xFFULL)
+#define GET_DEVID(x) ((x->conf >> 8) & 0xFFFFULL)
+#define GET_DOMID(x) ((x->conf >> 24) & 0xFFFFULL)
+#define GET_PASID(x) ((x->conf >> 40) & 0xFFFFFULL)
+
+/* iommu pmu conf1 masks */
+#define GET_DEVID_MASK(x) (x->conf1 & 0xFFFFULL)
+#define GET_DOMID_MASK(x) ((x->conf1 >> 16) & 0xFFFFULL)
+#define GET_PASID_MASK(x) ((x->conf1 >> 32) & 0xFFFFFULL)

static struct perf_amd_iommu __perf_iommu;

@@ -50,11 +49,11 @@ struct perf_amd_iommu {
*---------------------------------------------*/
PMU_FORMAT_ATTR(csource, "config:0-7");
PMU_FORMAT_ATTR(devid, "config:8-23");
-PMU_FORMAT_ATTR(pasid, "config:24-39");
-PMU_FORMAT_ATTR(domid, "config:40-55");
+PMU_FORMAT_ATTR(domid, "config:24-39");
+PMU_FORMAT_ATTR(pasid, "config:40-59");
PMU_FORMAT_ATTR(devid_mask, "config1:0-15");
-PMU_FORMAT_ATTR(pasid_mask, "config1:16-31");
-PMU_FORMAT_ATTR(domid_mask, "config1:32-47");
+PMU_FORMAT_ATTR(domid_mask, "config1:16-31");
+PMU_FORMAT_ATTR(pasid_mask, "config1:32-51");

static struct attribute *iommu_format_attrs[] = {
&format_attr_csource.attr,
@@ -150,10 +149,13 @@ static ssize_t _iommu_cpumask_show(struct device *dev,

/*---------------------------------------------*/

-static int get_next_avail_iommu_bnk_cntr(struct perf_amd_iommu *perf_iommu)
+static int get_next_avail_iommu_bnk_cntr(struct perf_event *event)
{
unsigned long flags;
- int shift, bank, cntr, retval;
+ u32 shift, bank, cntr;
+ int retval;
+ struct perf_amd_iommu *perf_iommu =
+ container_of(event->pmu, struct perf_amd_iommu, pmu);
int max_banks = perf_iommu->max_banks;
int max_cntrs = perf_iommu->max_counters;

@@ -166,7 +168,9 @@ static int get_next_avail_iommu_bnk_cntr(struct perf_amd_iommu *perf_iommu)
continue;
} else {
perf_iommu->cntr_assign_mask |= BIT_ULL(shift);
- retval = ((bank & 0xFF) << 8) | (cntr & 0xFF);
+ event->hw.iommu_bank = bank;
+ event->hw.iommu_cntr = cntr;
+ retval = 0;
goto out;
}
}
@@ -202,8 +206,6 @@ 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)
@@ -225,21 +227,9 @@ 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->conf = event->attr.config;
+ hwc->conf1 = event->attr.config1;

return 0;
}
@@ -247,26 +237,28 @@ static int perf_iommu_event_init(struct perf_event *event)
static void perf_iommu_enable_event(struct perf_event *ev)
{
struct amd_iommu *iommu = get_amd_iommu(0);
- u8 csource = _GET_CSOURCE(ev);
- u16 devid = _GET_DEVID(ev);
- u8 bank = _GET_BANK(ev);
- u8 cntr = _GET_CNTR(ev);
+ struct hw_perf_event *hwc = &ev->hw;
+ u8 bank = hwc->iommu_bank;
+ u8 cntr = hwc->iommu_cntr;
u64 reg = 0ULL;

- reg = csource;
+ reg = GET_CSOURCE(hwc);
amd_iommu_pc_set_reg(iommu, bank, cntr, IOMMU_PC_COUNTER_SRC_REG, &reg);

- reg = devid | (_GET_DEVID_MASK(ev) << 32);
+ reg = GET_DEVID_MASK(hwc);
+ reg = GET_DEVID(hwc) | (reg << 32);
if (reg)
reg |= BIT(31);
amd_iommu_pc_set_reg(iommu, bank, cntr, IOMMU_PC_DEVID_MATCH_REG, &reg);

- reg = _GET_PASID(ev) | (_GET_PASID_MASK(ev) << 32);
+ reg = GET_PASID_MASK(hwc);
+ reg = GET_PASID(hwc) | (reg << 32);
if (reg)
reg |= BIT(31);
amd_iommu_pc_set_reg(iommu, bank, cntr, IOMMU_PC_PASID_MATCH_REG, &reg);

- reg = _GET_DOMID(ev) | (_GET_DOMID_MASK(ev) << 32);
+ reg = GET_DOMID_MASK(hwc);
+ reg = GET_DOMID(hwc) | (reg << 32);
if (reg)
reg |= BIT(31);
amd_iommu_pc_set_reg(iommu, bank, cntr, IOMMU_PC_DOMID_MATCH_REG, &reg);
@@ -275,16 +267,16 @@ 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 hw_perf_event *hwc = &event->hw;
u64 reg = 0ULL;

- amd_iommu_pc_set_reg(iommu, _GET_BANK(event), _GET_CNTR(event),
+ amd_iommu_pc_set_reg(iommu, hwc->iommu_bank, hwc->iommu_cntr,
IOMMU_PC_COUNTER_SRC_REG, &reg);
}

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);

if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
return;
@@ -293,8 +285,10 @@ static void perf_iommu_start(struct perf_event *event, int flags)
hwc->state = 0;

if (flags & PERF_EF_RELOAD) {
- u64 prev_raw_count = local64_read(&hwc->prev_count);
- amd_iommu_pc_set_reg(iommu, _GET_BANK(event), _GET_CNTR(event),
+ u64 prev_raw_count = local64_read(&hwc->prev_count);
+ struct amd_iommu *iommu = get_amd_iommu(0);
+
+ amd_iommu_pc_set_reg(iommu, hwc->iommu_bank, hwc->iommu_cntr,
IOMMU_PC_COUNTER_REG, &prev_raw_count);
}

@@ -309,7 +303,7 @@ static void perf_iommu_read(struct perf_event *event)
struct hw_perf_event *hwc = &event->hw;
struct amd_iommu *iommu = get_amd_iommu(0);

- if (amd_iommu_pc_get_reg(iommu, _GET_BANK(event), _GET_CNTR(event),
+ if (amd_iommu_pc_get_reg(iommu, hwc->iommu_bank, hwc->iommu_cntr,
IOMMU_PC_COUNTER_REG, &count))
return;

@@ -329,7 +323,6 @@ static void perf_iommu_read(struct perf_event *event)
static void perf_iommu_stop(struct perf_event *event, int flags)
{
struct hw_perf_event *hwc = &event->hw;
- u64 config;

if (hwc->state & PERF_HES_UPTODATE)
return;
@@ -341,7 +334,6 @@ static void perf_iommu_stop(struct perf_event *event, int flags)
if (hwc->state & PERF_HES_UPTODATE)
return;

- config = hwc->config;
perf_iommu_read(event);
hwc->state |= PERF_HES_UPTODATE;
}
@@ -349,16 +341,12 @@ static void perf_iommu_stop(struct perf_event *event, int flags)
static int perf_iommu_add(struct perf_event *event, int flags)
{
int retval;
- struct perf_amd_iommu *perf_iommu =
- container_of(event->pmu, struct perf_amd_iommu, pmu);

event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;

/* request an iommu bank/counter */
- retval = get_next_avail_iommu_bnk_cntr(perf_iommu);
- if (retval != -ENOSPC)
- event->hw.extra_reg.reg = (u16)retval;
- else
+ retval = get_next_avail_iommu_bnk_cntr(event);
+ if (retval)
return retval;

if (flags & PERF_EF_START)
@@ -369,6 +357,7 @@ static int perf_iommu_add(struct perf_event *event, int flags)

static void perf_iommu_del(struct perf_event *event, int flags)
{
+ struct hw_perf_event *hwc = &event->hw;
struct perf_amd_iommu *perf_iommu =
container_of(event->pmu, struct perf_amd_iommu, pmu);

@@ -376,8 +365,7 @@ static void perf_iommu_del(struct perf_event *event, int flags)

/* clear the assigned iommu bank/counter */
clear_avail_iommu_bnk_cntr(perf_iommu,
- _GET_BANK(event),
- _GET_CNTR(event));
+ hwc->iommu_bank, hwc->iommu_cntr);

perf_event_update_userpage(event);
}
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 000fdb2..14c0767 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -165,6 +165,13 @@ struct hw_perf_event {
struct list_head bp_list;
};
#endif
+ struct { /* amd_iommu */
+ u8 iommu_bank;
+ u8 iommu_cntr;
+ u16 padding;
+ u64 conf;
+ u64 conf1;
+ };
};
/*
* If the event is a per task event, this will point to the task in
--
1.8.3.1