drm/amdgpu: fix max_entries calculation v4

Calculate the correct value for max_entries or we might run after the
page_address array.

v2: Xinhui pointed out we don't need the shift
v3: use local copy of start and simplify some calculation
v4: fix the case that we map less VA range than BO size

Signed-off-by: Christian König <christian.koenig@amd.com>
Fixes: 1e691e244487 drm/amdgpu: stop allocating dummy GTT nodes
Reviewed-by: xinhui pan <xinhui.pan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 620472a..37221b9 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1693,13 +1693,13 @@ static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
                uint64_t max_entries;
                uint64_t addr, last;
 
+               max_entries = mapping->last - start + 1;
                if (nodes) {
                        addr = nodes->start << PAGE_SHIFT;
-                       max_entries = (nodes->size - pfn) *
-                               AMDGPU_GPU_PAGES_IN_CPU_PAGE;
+                       max_entries = min((nodes->size - pfn) *
+                               AMDGPU_GPU_PAGES_IN_CPU_PAGE, max_entries);
                } else {
                        addr = 0;
-                       max_entries = S64_MAX;
                }
 
                if (pages_addr) {
@@ -1729,7 +1729,7 @@ static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
                        addr += pfn << PAGE_SHIFT;
                }
 
-               last = min((uint64_t)mapping->last, start + max_entries - 1);
+               last = start + max_entries - 1;
                r = amdgpu_vm_bo_update_mapping(adev, vm, false, false, resv,
                                                start, last, flags, addr,
                                                dma_addr, fence);