[Intel-gfx] [PATCH 5/6] drm/i915/perf: Whitelist OA counter and buffer registers

Umesh Nerlige Ramappa
2020-10-02T23:28:10Z

It is useful to have markers in the OA reports to identify triggered
reports. Whitelist some OA counters that can be used as markers.

A triggered report can be found faster if we can sample the HW tail and
head registers when the report was triggered. Whitelist OA buffer
specific registers.

v2:
- Bump up the perf revision (Lionel)
- Use indexing for counters (Lionel)
- Fix selftest for oa ticking register (Umesh)

v3: Pardon whitelisted registers for selftest (Umesh)

v4:
- Document whitelisted registers (Lionel)
- Fix live isolated whitelist for OA regs (Umesh)

v5:
- Free up whitelist slots. Remove GPU_TICKS and A20 counter (Piotr)
- Whitelist registers only if perf_stream_paranoid is set to 0 (Jon)

v6: Move oa whitelist array to i915_perf (Chris)

Signed-off-by: Piotr Maciejewski <piotr.maciejewski@intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
---
drivers/gpu/drm/i915/i915_perf.c | 18 +++++++++++++++++-
drivers/gpu/drm/i915/i915_reg.h | 8 ++++++++
2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index c5238dbda9de..f18577d3318b 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -1365,11 +1365,19 @@ free_noa_wait(struct i915_perf_stream *stream)
static struct i915_whitelist_reg gen9_oa_wl_regs[] = {
{ OAREPORTTRIG2, RING_FORCE_TO_NONPRIV_ACCESS_RW },
{ OAREPORTTRIG6, RING_FORCE_TO_NONPRIV_ACCESS_RW },
+ { OA_PERF_COUNTER_A(18), RING_FORCE_TO_NONPRIV_ACCESS_RW |
+ RING_FORCE_TO_NONPRIV_RANGE_4 },
+ { GEN8_OASTATUS, RING_FORCE_TO_NONPRIV_ACCESS_RD |
+ RING_FORCE_TO_NONPRIV_RANGE_4 },
};

static struct i915_whitelist_reg gen12_oa_wl_regs[] = {
{ GEN12_OAG_OAREPORTTRIG2, RING_FORCE_TO_NONPRIV_ACCESS_RW },
{ GEN12_OAG_OAREPORTTRIG6, RING_FORCE_TO_NONPRIV_ACCESS_RW },
+ { GEN12_OAG_PERF_COUNTER_A(18), RING_FORCE_TO_NONPRIV_ACCESS_RW |
+ RING_FORCE_TO_NONPRIV_RANGE_4 },
+ { GEN12_OAG_OASTATUS, RING_FORCE_TO_NONPRIV_ACCESS_RD |
+ RING_FORCE_TO_NONPRIV_RANGE_4 },
};

static int intel_engine_apply_oa_whitelist(struct i915_perf_stream *stream)
@@ -4541,8 +4549,16 @@ int i915_perf_ioctl_version(void)
* into the OA buffer. This applies only to gen8+. The feature can
* only be accessed if perf_stream_paranoid is set to 0 by privileged
* user.
+ *
+ * 7: Whitelist below OA registers for user to identify the location of
+ * triggered reports in the OA buffer. This applies only to gen8+.
+ * The feature can only be accessed if perf_stream_paranoid is set to
+ * 0 by privileged user.
+ *
+ * - OA buffer head/tail/status/buffer registers for read only
+ * - OA counters A18, A19, A20 for read/write
*/
- return 6;
+ return 7;
}

#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 031bff4dc2b1..57761dd4d70b 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -974,6 +974,14 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
#define OAREPORTTRIG8_NOA_SELECT_6_SHIFT 24
#define OAREPORTTRIG8_NOA_SELECT_7_SHIFT 28

+/* Performance counters registers */
+#define OA_PERF_COUNTER_A(idx) _MMIO(0x2800 + 8 * (idx))
+#define OA_PERF_COUNTER_A_UPPER(idx) _MMIO(0x2800 + 8 * (idx) + 4)
+
+/* Gen12 Performance counters registers */
+#define GEN12_OAG_PERF_COUNTER_A(idx) _MMIO(0xD980 + 8 * (idx))
+#define GEN12_OAG_PERF_COUNTER_A_UPPER(idx) _MMIO(0xD980 + 8 * (idx) + 4)
+
/* Same layout as OASTARTTRIGX */
#define GEN12_OAG_OASTARTTRIG1 _MMIO(0xd900)
#define GEN12_OAG_OASTARTTRIG2 _MMIO(0xd904)