drm/amdgpu: use only one reservation object for each VM v2

Reduces the locking and fencing overhead.

v2: add comment why we need the duplicates list in the GEM op.

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>

2 files changed, 9 insertions, 30 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index b75c3b235832..2f39fea10bd1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -455,11 +455,12 @@ static void amdgpu_gem_va_update_vm(struct amdgpu_device *adev,
         struct ttm_validate_buffer tv, *entry;
         struct amdgpu_bo_list_entry *vm_bos;
         struct ww_acquire_ctx ticket;
-        struct list_head list;
+        struct list_head list, duplicates;
         unsigned domain;
         int r;
 
         INIT_LIST_HEAD(&list);
+        INIT_LIST_HEAD(&duplicates);
 
         tv.bo = &bo_va->bo->tbo;
         tv.shared = true;
@@ -469,7 +470,8 @@ static void amdgpu_gem_va_update_vm(struct amdgpu_device *adev,
         if (!vm_bos)
                 return;
 
-        r = ttm_eu_reserve_buffers(&ticket, &list, true, NULL);
+        /* Provide duplicates to avoid -EALREADY */
+        r = ttm_eu_reserve_buffers(&ticket, &list, true, &duplicates);
         if (r)
                 goto error_free;
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 8927dc6dec7c..d30fbecac26e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -686,31 +686,6 @@ static int amdgpu_vm_update_ptes(struct amdgpu_device *adev,
 }
 
 /**
- * amdgpu_vm_fence_pts - fence page tables after an update
- *
- * @vm: requested vm
- * @start: start of GPU address range
- * @end: end of GPU address range
- * @fence: fence to use
- *
- * Fence the page tables in the range @start - @end (cayman+).
- *
- * Global and local mutex must be locked!
- */
-static void amdgpu_vm_fence_pts(struct amdgpu_vm *vm,
-                                uint64_t start, uint64_t end,
-                                struct fence *fence)
-{
-        unsigned i;
-
-        start >>= amdgpu_vm_block_size;
-        end >>= amdgpu_vm_block_size;
-
-        for (i = start; i <= end; ++i)
-                amdgpu_bo_fence(vm->page_tables[i].bo, fence, true);
-}
-
-/**
  * amdgpu_vm_bo_update_mapping - update a mapping in the vm page table
  *
  * @adev: amdgpu_device pointer
@@ -813,8 +788,7 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
         if (r)
                 goto error_free;
 
-        amdgpu_vm_fence_pts(vm, mapping->it.start,
-                            mapping->it.last + 1, f);
+        amdgpu_bo_fence(vm->page_directory, f, true);
         if (fence) {
                 fence_put(*fence);
                 *fence = fence_get(f);
@@ -1089,6 +1063,7 @@ int amdgpu_vm_bo_map(struct amdgpu_device *adev,
 
         /* walk over the address space and allocate the page tables */
         for (pt_idx = saddr; pt_idx <= eaddr; ++pt_idx) {
+                struct reservation_object *resv = vm->page_directory->tbo.resv;
                 struct amdgpu_bo *pt;
 
                 if (vm->page_tables[pt_idx].bo)
@@ -1097,11 +1072,13 @@ int amdgpu_vm_bo_map(struct amdgpu_device *adev,
                 /* drop mutex to allocate and clear page table */
                 mutex_unlock(&vm->mutex);
 
+                ww_mutex_lock(&resv->lock, NULL);
                 r = amdgpu_bo_create(adev, AMDGPU_VM_PTE_COUNT * 8,
                                      AMDGPU_GPU_PAGE_SIZE, true,
                                      AMDGPU_GEM_DOMAIN_VRAM,
                                      AMDGPU_GEM_CREATE_NO_CPU_ACCESS,
-                                     NULL, NULL, &pt);
+                                     NULL, resv, &pt);
+                ww_mutex_unlock(&resv->lock);
                 if (r)
                         goto error_free;