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Subject[PATCH 5/5] arm-cci: Fix CCI PMU event validation
Date
From: "Suzuki K. Poulose" <suzuki.poulose@arm.com>

We mask the event with the CCI_PMU_EVENT_MASK, before passing
the config to pmu_validate_hw_event(), which causes extra bits
to be ignored and qualifies an invalid event code as valid.

e.g,
$ perf stat -a -C 0 -e CCI_400/config=0x1ff,name=cycles/ sleep 1
Performance counter stats for 'system wide':

506951142 cycles

1.013879626 seconds time elapsed

where, cycles has an event coding of 0xff. This patch also removes
the unnecessary 'event' mask in pmu_write_register, since the config_base
is set by the pmu code after the event is validated.

Helps in killing CCI_PMU_EVENT_MASK from common code.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
---
drivers/bus/arm-cci.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index f86f096..438a121 100644
--- a/drivers/bus/arm-cci.c
+++ b/drivers/bus/arm-cci.c
@@ -191,11 +191,14 @@ static int pmu_is_valid_master_event(u8 ev_code)
ev_code <= pmu->model->event_ranges[CCI_IF_MASTER].max;
}

-static int pmu_validate_hw_event(u8 hw_event)
+static int pmu_validate_hw_event(u32 hw_event)
{
u8 ev_source = CCI_PMU_EVENT_SOURCE(hw_event);
u8 ev_code = CCI_PMU_EVENT_CODE(hw_event);

+ if (hw_event & ~CCI_PMU_EVENT_MASK)
+ return -ENOENT;
+
switch (ev_source) {
case CCI_PORT_S0:
case CCI_PORT_S1:
@@ -265,7 +268,6 @@ static void pmu_enable_counter(int idx)

static void pmu_set_event(int idx, unsigned long event)
{
- event &= CCI_PMU_EVENT_MASK;
pmu_write_register(event, idx, CCI_PMU_EVT_SEL);
}

@@ -282,7 +284,7 @@ static int pmu_get_event_idx(struct cci_pmu_hw_events *hw, struct perf_event *ev
{
struct cci_pmu *cci_pmu = to_cci_pmu(event->pmu);
struct hw_perf_event *hw_event = &event->hw;
- unsigned long cci_event = hw_event->config_base & CCI_PMU_EVENT_MASK;
+ unsigned long cci_event = hw_event->config_base;
int idx;

if (cci_event == CCI_PMU_CYCLES) {
@@ -303,7 +305,7 @@ static int pmu_get_event_idx(struct cci_pmu_hw_events *hw, struct perf_event *ev
static int pmu_map_event(struct perf_event *event)
{
int mapping;
- u8 config = event->attr.config & CCI_PMU_EVENT_MASK;
+ u32 config = event->attr.config;

if (event->attr.type < PERF_TYPE_MAX)
return -ENOENT;
--
1.7.9.5



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