drm/msm/a6xx: Use posamble to reset counters on preemption

Use the postamble to reset perf counters when switching between rings,
except when sysprof is enabled, analogously to how they are reset
between submissions when switching pagetables.

Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Tested-by: Rob Clark <robdclark@gmail.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8450-HDK
Signed-off-by: Antonino Maniscalco <antomani103@gmail.com>
Patchwork: https://patchwork.freedesktop.org/patch/618024/
Signed-off-by: Rob Clark <robdclark@chromium.org>

4 files changed, 81 insertions, 2 deletions

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index 52ef481548b6..be306ae33c08 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -280,6 +280,8 @@ static void a6xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
 static void a6xx_emit_set_pseudo_reg(struct msm_ringbuffer *ring,
 		struct a6xx_gpu *a6xx_gpu, struct msm_gpu_submitqueue *queue)
 {
+	u64 preempt_postamble;
+
 	OUT_PKT7(ring, CP_SET_PSEUDO_REG, 12);
 
 	OUT_RING(ring, SMMU_INFO);
@@ -303,6 +305,16 @@ static void a6xx_emit_set_pseudo_reg(struct msm_ringbuffer *ring,
 	/* seems OK to set to 0 to disable it */
 	OUT_RING(ring, 0);
 	OUT_RING(ring, 0);
+
+	/* Emit postamble to clear perfcounters */
+	preempt_postamble = a6xx_gpu->preempt_postamble_iova;
+
+	OUT_PKT7(ring, CP_SET_AMBLE, 3);
+	OUT_RING(ring, lower_32_bits(preempt_postamble));
+	OUT_RING(ring, upper_32_bits(preempt_postamble));
+	OUT_RING(ring, CP_SET_AMBLE_2_DWORDS(
+				 a6xx_gpu->preempt_postamble_len) |
+			 CP_SET_AMBLE_2_TYPE(KMD_AMBLE_TYPE));
 }
 
 static void a7xx_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit)
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
index 66181d163a61..4aceffb6aae8 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
@@ -71,6 +71,12 @@ struct a6xx_gpu {
 	bool uses_gmem;
 	bool skip_save_restore;
 
+	struct drm_gem_object *preempt_postamble_bo;
+	void *preempt_postamble_ptr;
+	uint64_t preempt_postamble_iova;
+	uint64_t preempt_postamble_len;
+	bool postamble_enabled;
+
 	struct a6xx_gmu gmu;
 
 	struct drm_gem_object *shadow_bo;
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_preempt.c b/drivers/gpu/drm/msm/adreno/a6xx_preempt.c
index fd2a90360740..21e333cb6342 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_preempt.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_preempt.c
@@ -97,6 +97,43 @@ static void a6xx_preempt_timer(struct timer_list *t)
 	kthread_queue_work(gpu->worker, &gpu->recover_work);
 }
 
+static void preempt_prepare_postamble(struct a6xx_gpu *a6xx_gpu)
+{
+	u32 *postamble = a6xx_gpu->preempt_postamble_ptr;
+	u32 count = 0;
+
+	postamble[count++] = PKT7(CP_REG_RMW, 3);
+	postamble[count++] = REG_A6XX_RBBM_PERFCTR_SRAM_INIT_CMD;
+	postamble[count++] = 0;
+	postamble[count++] = 1;
+
+	postamble[count++] = PKT7(CP_WAIT_REG_MEM, 6);
+	postamble[count++] = CP_WAIT_REG_MEM_0_FUNCTION(WRITE_EQ);
+	postamble[count++] = CP_WAIT_REG_MEM_1_POLL_ADDR_LO(
+				REG_A6XX_RBBM_PERFCTR_SRAM_INIT_STATUS);
+	postamble[count++] = CP_WAIT_REG_MEM_2_POLL_ADDR_HI(0);
+	postamble[count++] = CP_WAIT_REG_MEM_3_REF(0x1);
+	postamble[count++] = CP_WAIT_REG_MEM_4_MASK(0x1);
+	postamble[count++] = CP_WAIT_REG_MEM_5_DELAY_LOOP_CYCLES(0);
+
+	a6xx_gpu->preempt_postamble_len = count;
+
+	a6xx_gpu->postamble_enabled = true;
+}
+
+static void preempt_disable_postamble(struct a6xx_gpu *a6xx_gpu)
+{
+	u32 *postamble = a6xx_gpu->preempt_postamble_ptr;
+
+	/*
+	 * Disable the postamble by replacing the first packet header with a NOP
+	 * that covers the whole buffer.
+	 */
+	*postamble = PKT7(CP_NOP, (a6xx_gpu->preempt_postamble_len - 1));
+
+	a6xx_gpu->postamble_enabled = false;
+}
+
 void a6xx_preempt_irq(struct msm_gpu *gpu)
 {
 	uint32_t status;
@@ -187,6 +224,7 @@ void a6xx_preempt_trigger(struct msm_gpu *gpu)
 	unsigned long flags;
 	struct msm_ringbuffer *ring;
 	unsigned int cntl;
+	bool sysprof;
 
 	if (gpu->nr_rings == 1)
 		return;
@@ -271,6 +309,15 @@ void a6xx_preempt_trigger(struct msm_gpu *gpu)
 	/* Start a timer to catch a stuck preemption */
 	mod_timer(&a6xx_gpu->preempt_timer, jiffies + msecs_to_jiffies(10000));
 
+	/* Enable or disable postamble as needed */
+	sysprof = refcount_read(&a6xx_gpu->base.base.sysprof_active) > 1;
+
+	if (!sysprof && !a6xx_gpu->postamble_enabled)
+		preempt_prepare_postamble(a6xx_gpu);
+
+	if (sysprof && a6xx_gpu->postamble_enabled)
+		preempt_disable_postamble(a6xx_gpu);
+
 	/* Set the preemption state to triggered */
 	set_preempt_state(a6xx_gpu, PREEMPT_TRIGGERED);
 
@@ -375,6 +422,17 @@ void a6xx_preempt_init(struct msm_gpu *gpu)
 	a6xx_gpu->uses_gmem = 1;
 	a6xx_gpu->skip_save_restore = 1;
 
+	a6xx_gpu->preempt_postamble_ptr  = msm_gem_kernel_new(gpu->dev,
+			PAGE_SIZE,
+			MSM_BO_WC | MSM_BO_MAP_PRIV | MSM_BO_GPU_READONLY,
+			gpu->aspace, &a6xx_gpu->preempt_postamble_bo,
+			&a6xx_gpu->preempt_postamble_iova);
+
+	preempt_prepare_postamble(a6xx_gpu);
+
+	if (IS_ERR(a6xx_gpu->preempt_postamble_ptr))
+		goto fail;
+
 	timer_setup(&a6xx_gpu->preempt_timer, a6xx_preempt_timer, 0);
 
 	return;
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
index ca8812c88a6b..0f79d2ad515e 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
@@ -670,12 +670,15 @@ OUT_PKT4(struct msm_ringbuffer *ring, uint16_t regindx, uint16_t cnt)
 	OUT_RING(ring, PKT4(regindx, cnt));
 }
 
+#define PKT7(opcode, cnt) \
+	(CP_TYPE7_PKT | (cnt << 0) | (PM4_PARITY(cnt) << 15) | \
+		((opcode & 0x7F) << 16) | (PM4_PARITY(opcode) << 23))
+
 static inline void
 OUT_PKT7(struct msm_ringbuffer *ring, uint8_t opcode, uint16_t cnt)
 {
 	adreno_wait_ring(ring, cnt + 1);
-	OUT_RING(ring, CP_TYPE7_PKT | (cnt << 0) | (PM4_PARITY(cnt) << 15) |
-		((opcode & 0x7F) << 16) | (PM4_PARITY(opcode) << 23));
+	OUT_RING(ring, PKT7(opcode, cnt));
 }
 
 struct msm_gpu *a2xx_gpu_init(struct drm_device *dev);