[PATCH 08/10] drm/etnaviv: make it possible to reconfigure perf counter

[Christian Gmeiner]

Each perf counter 'unit' consits of a multipler configuration register
and a register to read the selected value. Extend the uapi to handle
this case gracefully. Before the readback is done the mux (config_reg)
get reconfigured (vale).

Signed-off-by: Christian Gmeiner <christian.gmeiner at gmail.com>
---
 drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c | 7 +++++--
 drivers/gpu/drm/etnaviv/etnaviv_gpu.c        | 3 +++
 drivers/gpu/drm/etnaviv/etnaviv_gpu.h        | 3 +++
 include/uapi/drm/etnaviv_drm.h               | 6 +++++-
 4 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
index a69eff7..08f9b3d 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
@@ -298,14 +298,17 @@ static int submit_readback(struct etnaviv_gem_submit *submit,
 			return -EINVAL;
 		}
 
-		if (r->flags) {
-			DRM_ERROR("readback flags not 0");
+		if (r->flags > ETNA_READBACK_PERF) {
+			DRM_ERROR("invalid readback flags");
 			return -EINVAL;
 		}
 
 		cmdbuf->readbacks[i].bo_vma = etnaviv_gem_vmap(&bo->obj->base);
 		cmdbuf->readbacks[i].offset = r->readback_offset;
 		cmdbuf->readbacks[i].reg = r->reg;
+		cmdbuf->readbacks[i].flags = r->flags;
+		cmdbuf->readbacks[i].perf_reg = r->perf_reg;
+		cmdbuf->readbacks[i].perf_value = r->perf_value;
 	}
 
 	return 0;
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index 2aa1a26..b22212c 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -1379,6 +1379,9 @@ static void etnaviv_process_readbacks(struct etnaviv_gpu *gpu,
 		const u32 val = gpu_read(gpu, readback->reg);
 		u32 *bo = readback->bo_vma;
 
+		if (readback->flags & ETNA_READBACK_PERF)
+			gpu_write(gpu, readback->perf_reg, readback->perf_value);
+
 		*(bo + readback->offset) = val;
 	}
 }
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
index 21a4314..02f15c0 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.h
@@ -91,6 +91,9 @@ struct etnaviv_readback {
 	u32 *bo_vma;
 	u32 offset;
 	u32 reg;
+	u32 flags;
+	u32 perf_reg;
+	u32 perf_value;
 };
 
 struct etnaviv_event {
diff --git a/include/uapi/drm/etnaviv_drm.h b/include/uapi/drm/etnaviv_drm.h
index 0d30604..f2e24bb 100644
--- a/include/uapi/drm/etnaviv_drm.h
+++ b/include/uapi/drm/etnaviv_drm.h
@@ -150,11 +150,15 @@ struct drm_etnaviv_gem_submit_bo {
 	__u64 presumed;       /* in/out, presumed buffer address */
 };
 
+#define ETNA_READBACK_ONLY     0x0000
+#define ETNA_READBACK_PERF     0x0001
 struct drm_etnaviv_gem_submit_readback {
 	__u32 readback_offset;/* in, offset from readback_bo */
 	__u32 readback_idx;   /* in, index of readback_bo buffer */
 	__u32 reg;            /* in, register to read */
-	__u32 flags;          /* in, needs to be 0 */
+	__u32 flags;          /* in, ETNA_READBACK_* */
+	__u32 perf_reg;       /* in, register to write */
+	__u32 perf_value;     /* in, value to write */
 };
 
 /* Each cmdstream submit consists of a table of buffers involved, and
-- 
2.9.3