[PATCH] drm/amdgpu: fix a kcq hang issue for SRIOV

[Emily Deng <Emily.Deng-5C7GfCeVMHo@public.gmane.org>]

issue:
the vmflush in KCQ could be preempted (not like GFX ring
which doesn't allow preemption in ring buffer) and this lead
to vm flush fail when there is a world switch during
the vm flush procedure (between write invalidate request
and query invalidate ack)

fix:
separate vm flush for gfx and compute ring, and use
the new format command in compute's vm flush which
use only one package so no preemption could allowed

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Signed-off-by: Emily Deng <Emily.Deng@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h      |  1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h |  2 ++
 drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c    | 10 +++++++++-
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c    | 18 +++++++++++++-----
 4 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index a7e2229..986659f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1790,6 +1790,7 @@ amdgpu_get_sdma_instance(struct amdgpu_ring *ring)
 #define amdgpu_ring_emit_rreg(r, d) (r)->funcs->emit_rreg((r), (d))
 #define amdgpu_ring_emit_wreg(r, d, v) (r)->funcs->emit_wreg((r), (d), (v))
 #define amdgpu_ring_emit_reg_wait(r, d, v, m) (r)->funcs->emit_reg_wait((r), (d), (v), (m))
+#define amdgpu_ring_emit_reg_wait1(r, d0, d1, v, m) (r)->funcs->emit_reg_wait1((r), (d0), (d1), (v), (m))
 #define amdgpu_ring_emit_tmz(r, b) (r)->funcs->emit_tmz((r), (b))
 #define amdgpu_ring_pad_ib(r, ib) ((r)->funcs->pad_ib((r), (ib)))
 #define amdgpu_ring_init_cond_exec(r) (r)->funcs->init_cond_exec((r))
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
index 1d0d250..d85df5d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
@@ -152,6 +152,8 @@ struct amdgpu_ring_funcs {
 	void (*emit_wreg)(struct amdgpu_ring *ring, uint32_t reg, uint32_t val);
 	void (*emit_reg_wait)(struct amdgpu_ring *ring, uint32_t reg,
 			      uint32_t val, uint32_t mask);
+	void (*emit_reg_wait1)(struct amdgpu_ring *ring, uint32_t reg0,
+				uint32_t reg1, uint32_t val, uint32_t mask);
 	void (*emit_tmz)(struct amdgpu_ring *ring, bool start);
 	/* priority functions */
 	void (*set_priority) (struct amdgpu_ring *ring,
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index 1ae3de1..509c9d2 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -4078,6 +4078,13 @@ static void gfx_v9_0_ring_emit_reg_wait(struct amdgpu_ring *ring, uint32_t reg,
 	gfx_v9_0_wait_reg_mem(ring, 0, 0, 0, reg, 0, val, mask, 0x20);
 }
 
+static void gfx_v9_0_ring_emit_reg_wait_compute(struct amdgpu_ring *ring,
+					uint32_t reg0, uint32_t reg1,
+					uint32_t val, uint32_t mask)
+{
+	gfx_v9_0_wait_reg_mem(ring, 0, 0, 1, reg0, reg1, val, mask, 0x20);
+}
+
 static void gfx_v9_0_set_gfx_eop_interrupt_state(struct amdgpu_device *adev,
 						 enum amdgpu_interrupt_state state)
 {
@@ -4415,7 +4422,7 @@ static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_compute = {
 		7 + /* gfx_v9_0_ring_emit_hdp_flush */
 		5 + /* hdp invalidate */
 		7 + /* gfx_v9_0_ring_emit_pipeline_sync */
-		SOC15_FLUSH_GPU_TLB_NUM_WREG * 5 +
+		(SOC15_FLUSH_GPU_TLB_NUM_WREG - 1) * 5 +
 		SOC15_FLUSH_GPU_TLB_NUM_REG_WAIT * 7 +
 		2 + /* gfx_v9_0_ring_emit_vm_flush */
 		8 + 8 + 8, /* gfx_v9_0_ring_emit_fence x3 for user fence, vm fence */
@@ -4433,6 +4440,7 @@ static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_compute = {
 	.set_priority = gfx_v9_0_ring_set_priority_compute,
 	.emit_wreg = gfx_v9_0_ring_emit_wreg,
 	.emit_reg_wait = gfx_v9_0_ring_emit_reg_wait,
+	.emit_reg_wait1 = gfx_v9_0_ring_emit_reg_wait_compute,
 };
 
 static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_kiq = {
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index e687363..968447d 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -385,11 +385,19 @@ static uint64_t gmc_v9_0_emit_flush_gpu_tlb(struct amdgpu_ring *ring,
 	amdgpu_ring_emit_wreg(ring, hub->ctx0_ptb_addr_hi32 + (2 * vmid),
 			      upper_32_bits(pd_addr));
 
-	amdgpu_ring_emit_wreg(ring, hub->vm_inv_eng0_req + eng, req);
-
-	/* wait for the invalidate to complete */
-	amdgpu_ring_emit_reg_wait(ring, hub->vm_inv_eng0_ack + eng,
-				  1 << vmid, 1 << vmid);
+    /* The world switch cannot be allowed to occur while
+       some invalidation controller code is waiting for an ack.
+       To workaround the hardware restriction, replace the original
+       two command with one command for compute ring */
+	if (ring->funcs->type == AMDGPU_RING_TYPE_COMPUTE && amdgpu_sriov_vf(adev)) {
+		amdgpu_ring_emit_reg_wait1(ring, hub->vm_inv_eng0_req + eng,
+				   hub->vm_inv_eng0_ack + eng, req, 1 << vmid);
+	} else {
+		amdgpu_ring_emit_wreg(ring, hub->vm_inv_eng0_req + eng, req);
+		/* wait for the invalidate to complete */
+		amdgpu_ring_emit_reg_wait(ring, hub->vm_inv_eng0_ack + eng,
+			   1 << vmid, 1 << vmid);
+	}
 
 	return pd_addr;
 }
-- 
2.7.4

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