[PATCH 16/34] drm/amdgpu/gfx10: wait for reset done before remap

[Alex Deucher]

From: Jiadong Zhu <jiadong....@amd.com>

There is a racing condition that cp firmware modifies
MQD in reset sequence after driver updates it for
remapping. We have to wait till CP_HQD_ACTIVE becoming
false then remap the queue.

v2: fix KIQ locking (Alex)

Signed-off-by: Jiadong Zhu <jiadong....@amd.com>
Reviewed-by: Alex Deucher <alexander.deuc...@amd.com>
Signed-off-by: Alex Deucher <alexander.deuc...@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 41 +++++++++++++++++++-------
 1 file changed, 30 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c 
b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
index 5cc0d22d1e2f..e9d93bf909db 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
@@ -9513,7 +9513,7 @@ static int gfx_v10_0_reset_kcq(struct amdgpu_ring *ring,
        struct amdgpu_kiq *kiq = &adev->gfx.kiq[0];
        struct amdgpu_ring *kiq_ring = &kiq->ring;
        unsigned long flags;
-       int r;
+       int i, r;
 
        if (!kiq->pmf || !kiq->pmf->kiq_unmap_queues)
                return -EINVAL;
@@ -9521,8 +9521,8 @@ static int gfx_v10_0_reset_kcq(struct amdgpu_ring *ring,
        spin_lock_irqsave(&kiq->ring_lock, flags);
 
        if (amdgpu_ring_alloc(kiq_ring, kiq->pmf->unmap_queues_size)) {
-               r = -ENOMEM;
-               goto out;
+               spin_unlock_irqrestore(&kiq->ring_lock, flags);
+               return -ENOMEM;
        }
 
        kiq->pmf->kiq_unmap_queues(kiq_ring, ring, RESET_QUEUES,
@@ -9530,13 +9530,33 @@ static int gfx_v10_0_reset_kcq(struct amdgpu_ring *ring,
        amdgpu_ring_commit(kiq_ring);
 
        r = amdgpu_ring_test_ring(kiq_ring);
+       spin_unlock_irqrestore(&kiq->ring_lock, flags);
        if (r)
-               goto out;
+               return r;
+
+       /* make sure dequeue is complete*/
+       gfx_v10_0_set_safe_mode(adev, 0);
+       mutex_lock(&adev->srbm_mutex);
+       nv_grbm_select(adev, ring->me, ring->pipe, ring->queue, 0);
+       for (i = 0; i < adev->usec_timeout; i++) {
+               if (!(RREG32_SOC15(GC, 0, mmCP_HQD_ACTIVE) & 1))
+                       break;
+               udelay(1);
+       }
+       if (i >= adev->usec_timeout)
+               r = -ETIMEDOUT;
+       nv_grbm_select(adev, 0, 0, 0, 0);
+       mutex_unlock(&adev->srbm_mutex);
+       gfx_v10_0_unset_safe_mode(adev, 0);
+       if (r) {
+               dev_err(adev->dev, "fail to wait on hqd deactive\n");
+               return r;
+       }
 
        r = amdgpu_bo_reserve(ring->mqd_obj, false);
        if (unlikely(r != 0)){
                dev_err(adev->dev, "fail to resv mqd_obj\n");
-               goto out;
+               return r;
        }
        r = amdgpu_bo_kmap(ring->mqd_obj, (void **)&ring->mqd_ptr);
        if (!r) {
@@ -9545,21 +9565,20 @@ static int gfx_v10_0_reset_kcq(struct amdgpu_ring *ring,
                ring->mqd_ptr = NULL;
        }
        amdgpu_bo_unreserve(ring->mqd_obj);
-       if (r){
+       if (r) {
                dev_err(adev->dev, "fail to unresv mqd_obj\n");
-               goto out;
+               return r;
        }
 
+       spin_lock_irqsave(&kiq->ring_lock, flags);
        if (amdgpu_ring_alloc(kiq_ring, kiq->pmf->map_queues_size)) {
-               r = -ENOMEM;
-               goto out;
+               spin_unlock_irqrestore(&kiq->ring_lock, flags);
+               return -ENOMEM;
        }
        kiq->pmf->kiq_map_queues(kiq_ring, ring);
        amdgpu_ring_commit(kiq_ring);
 
        r = amdgpu_ring_test_ring(kiq_ring);
-
-out:
        spin_unlock_irqrestore(&kiq->ring_lock, flags);
        if (r)
                return r;
-- 
2.45.2