drm/amdgpu: fix context switch

Properly protect the state and also handle submission failures.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Monk Liu <monk.liu@amd.com>

5 files changed, 26 insertions, 21 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 72d9d9ec5c9f..003fa2d12bfb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -893,6 +893,7 @@ struct amdgpu_ib {
         struct amdgpu_fence             *fence;
         struct amdgpu_user_fence        *user;
         struct amdgpu_vm                *vm;
+        struct amdgpu_ctx               *ctx;
         struct amdgpu_sync              sync;
         uint32_t                        gds_base, gds_size;
         uint32_t                        gws_base, gws_size;
@@ -943,9 +944,7 @@ struct amdgpu_ring {
         unsigned                wptr_offs;
         unsigned                next_rptr_offs;
         unsigned                fence_offs;
-        struct drm_file         *current_filp;
-        unsigned                current_ctx;
-        bool                    need_ctx_switch;
+        struct amdgpu_ctx       *current_ctx;
         enum amdgpu_ring_type   type;
         char                    name[16];
 };
@@ -1236,7 +1235,7 @@ struct amdgpu_cs_chunk {
 struct amdgpu_cs_parser {
         struct amdgpu_device    *adev;
         struct drm_file         *filp;
-        uint32_t ctx_id;
+        struct amdgpu_ctx       *ctx;
         struct amdgpu_bo_list *bo_list;
         /* chunks */
         unsigned                nchunks;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index de17f845a84b..ecb30a1a73cc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -138,7 +138,11 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data)
         if (!cs->in.num_chunks)
                 goto out;
 
-        p->ctx_id = cs->in.ctx_id;
+        p->ctx = amdgpu_ctx_get(fpriv, cs->in.ctx_id);
+        if (!p->ctx) {
+                r = -EINVAL;
+                goto out;
+        }
         p->bo_list = amdgpu_bo_list_get(fpriv, cs->in.bo_list_handle);
 
         /* get chunks */
@@ -445,6 +449,8 @@ static void amdgpu_cs_parser_fini(struct amdgpu_cs_parser *parser, int error, bo
                                            &parser->validated);
         }
 
+        if (parser->ctx)
+                amdgpu_ctx_put(parser->ctx);
         if (parser->bo_list)
                 amdgpu_bo_list_put(parser->bo_list);
         drm_free_large(parser->vm_bos);
@@ -639,13 +645,7 @@ static int amdgpu_cs_ib_fill(struct amdgpu_device *adev,
                 ib->length_dw = chunk_ib->ib_bytes / 4;
 
                 ib->flags = chunk_ib->flags;
-
-                if ((ib->ring->current_filp != parser->filp) ||
-                    (ib->ring->current_ctx != parser->ctx_id)) {
-                        ib->ring->need_ctx_switch = true;
-                        ib->ring->current_ctx = parser->ctx_id;
-                        ib->ring->current_filp = parser->filp;
-                }
+                ib->ctx = parser->ctx;
 
                 ib_bo = &parser->ib_bos[j];
                 ib_bo->robj = aobj;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
index 74ed94ee7102..560c5fd347be 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
@@ -140,6 +140,7 @@ int amdgpu_ib_schedule(struct amdgpu_device *adev, unsigned num_ibs,
 {
         struct amdgpu_ib *ib = &ibs[0];
         struct amdgpu_ring *ring;
+        struct amdgpu_ctx *ctx, *old_ctx;
         struct amdgpu_vm *vm;
         unsigned i;
         int r = 0;
@@ -148,6 +149,7 @@ int amdgpu_ib_schedule(struct amdgpu_device *adev, unsigned num_ibs,
                 return -EINVAL;
 
         ring = ibs->ring;
+        ctx = ibs->ctx;
         vm = ibs->vm;
 
         if (!ring->ready) {
@@ -189,19 +191,23 @@ int amdgpu_ib_schedule(struct amdgpu_device *adev, unsigned num_ibs,
         if (ring->funcs->emit_hdp_flush)
                 amdgpu_ring_emit_hdp_flush(ring);
 
+        old_ctx = ring->current_ctx;
         for (i = 0; i < num_ibs; ++i) {
                 ib = &ibs[i];
 
-                if (ib->ring != ring) {
+                if (ib->ring != ring || ib->ctx != ctx || ib->vm != vm) {
+                        ring->current_ctx = old_ctx;
                         amdgpu_ring_unlock_undo(ring);
                         return -EINVAL;
                 }
                 amdgpu_ring_emit_ib(ring, ib);
+                ring->current_ctx = ctx;
         }
 
         r = amdgpu_fence_emit(ring, owner, &ib->fence);
         if (r) {
                 dev_err(adev->dev, "failed to emit fence (%d)\n", r);
+                ring->current_ctx = old_ctx;
                 amdgpu_ring_unlock_undo(ring);
                 return r;
         }
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
index 855b5272f4b5..5315c13a8921 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
@@ -2516,19 +2516,20 @@ static bool gfx_v7_0_ring_emit_semaphore(struct amdgpu_ring *ring,
 static void gfx_v7_0_ring_emit_ib(struct amdgpu_ring *ring,
                                   struct amdgpu_ib *ib)
 {
+        bool need_ctx_switch = ring->current_ctx != ib->ctx;
         u32 header, control = 0;
         u32 next_rptr = ring->wptr + 5;
 
         /* drop the CE preamble IB for the same context */
         if ((ring->type == AMDGPU_RING_TYPE_GFX) &&
             (ib->flags & AMDGPU_IB_FLAG_PREAMBLE) &&
-            !ring->need_ctx_switch)
+            !need_ctx_switch)
                 return;
 
         if (ring->type == AMDGPU_RING_TYPE_COMPUTE)
                 control |= INDIRECT_BUFFER_VALID;
 
-        if (ring->need_ctx_switch && ring->type == AMDGPU_RING_TYPE_GFX)
+        if (need_ctx_switch && ring->type == AMDGPU_RING_TYPE_GFX)
                 next_rptr += 2;
 
         next_rptr += 4;
@@ -2539,10 +2540,9 @@ static void gfx_v7_0_ring_emit_ib(struct amdgpu_ring *ring,
         amdgpu_ring_write(ring, next_rptr);
 
         /* insert SWITCH_BUFFER packet before first IB in the ring frame */
-        if (ring->need_ctx_switch && ring->type == AMDGPU_RING_TYPE_GFX) {
+        if (need_ctx_switch && ring->type == AMDGPU_RING_TYPE_GFX) {
                 amdgpu_ring_write(ring, PACKET3(PACKET3_SWITCH_BUFFER, 0));
                 amdgpu_ring_write(ring, 0);
-                ring->need_ctx_switch = false;
         }
 
         if (ib->flags & AMDGPU_IB_FLAG_CE)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
index 63ed3b01cea1..188a7abbddaf 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -3645,19 +3645,20 @@ static void gfx_v8_0_ring_emit_hdp_flush(struct amdgpu_ring *ring)
 static void gfx_v8_0_ring_emit_ib(struct amdgpu_ring *ring,
                                   struct amdgpu_ib *ib)
 {
+        bool need_ctx_switch = ring->current_ctx != ib->ctx;
         u32 header, control = 0;
         u32 next_rptr = ring->wptr + 5;
 
         /* drop the CE preamble IB for the same context */
         if ((ring->type == AMDGPU_RING_TYPE_GFX) &&
             (ib->flags & AMDGPU_IB_FLAG_PREAMBLE) &&
-            !ring->need_ctx_switch)
+            !need_ctx_switch)
                 return;
 
         if (ring->type == AMDGPU_RING_TYPE_COMPUTE)
                 control |= INDIRECT_BUFFER_VALID;
 
-        if (ring->need_ctx_switch && ring->type == AMDGPU_RING_TYPE_GFX)
+        if (need_ctx_switch && ring->type == AMDGPU_RING_TYPE_GFX)
                 next_rptr += 2;
 
         next_rptr += 4;
@@ -3668,10 +3669,9 @@ static void gfx_v8_0_ring_emit_ib(struct amdgpu_ring *ring,
         amdgpu_ring_write(ring, next_rptr);
 
         /* insert SWITCH_BUFFER packet before first IB in the ring frame */
-        if (ring->need_ctx_switch && ring->type == AMDGPU_RING_TYPE_GFX) {
+        if (need_ctx_switch && ring->type == AMDGPU_RING_TYPE_GFX) {
                 amdgpu_ring_write(ring, PACKET3(PACKET3_SWITCH_BUFFER, 0));
                 amdgpu_ring_write(ring, 0);
-                ring->need_ctx_switch = false;
         }
 
         if (ib->flags & AMDGPU_IB_FLAG_CE)