drm/amdgpu/userq: dont lock root bo with userq_mutex held

Do not hold reservation lock for root bo if userq_mutex
is already held in the call flow this cause a lock
issue with ttm_bo_delayed_delete.

Its better to lock the vm->root.bo first and then go ahead
with userq_mutex so userq_mutex threads dont get stuck until
the reservation lock is held.

In this case it helps in the function amdgpu_userq_buffer_vas_mapped
for each queue during restore_all.

Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
index 33ffbf8948010b563b230d4bca83dfa782bb1d78..a0a45c5e6335f188380d66e10c1ce8224fdd3fdc 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
@@ -270,15 +270,13 @@ static bool amdgpu_userq_buffer_va_mapped(struct amdgpu_vm *vm, u64 addr)
        struct amdgpu_bo_va_mapping *mapping;
        bool r;
 
-       if (amdgpu_bo_reserve(vm->root.bo, false))
-               return false;
+       dma_resv_assert_held(vm->root.bo->tbo.base.resv);
 
        mapping = amdgpu_vm_bo_lookup_mapping(vm, addr);
        if (!IS_ERR_OR_NULL(mapping) && atomic_read(&mapping->bo_va->userq_va_mapped))
                r = true;
        else
                r = false;
-       amdgpu_bo_unreserve(vm->root.bo);
 
        return r;
 }
@@ -991,10 +989,16 @@ int amdgpu_userq_ioctl(struct drm_device *dev, void *data,
 static int
 amdgpu_userq_restore_all(struct amdgpu_userq_mgr *uq_mgr)
 {
+       struct amdgpu_fpriv *fpriv = uq_mgr_to_fpriv(uq_mgr);
+       struct amdgpu_vm *vm = &fpriv->vm;
        struct amdgpu_usermode_queue *queue;
        unsigned long queue_id;
        int ret = 0, r;
 
+
+       if (amdgpu_bo_reserve(vm->root.bo, false))
+               return false;
+
        mutex_lock(&uq_mgr->userq_mutex);
        /* Resume all the queues for this process */
        xa_for_each(&uq_mgr->userq_xa, queue_id, queue) {
@@ -1012,6 +1016,7 @@ amdgpu_userq_restore_all(struct amdgpu_userq_mgr *uq_mgr)
 
        }
        mutex_unlock(&uq_mgr->userq_mutex);
+       amdgpu_bo_unreserve(vm->root.bo);
 
        if (ret)
                drm_file_err(uq_mgr->file,