drm/amdgpu: use the TTM dummy page instead of allocating one

We have a global dummy page in TTM, use that one instead of allocating a
new one.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 13 insertions, 16 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
index 008eaee57114..137145dd14a9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
@@ -68,17 +68,15 @@
  */
 static int amdgpu_gart_dummy_page_init(struct amdgpu_device *adev)
 {
-        if (adev->dummy_page.page)
+        struct page *dummy_page = adev->mman.bdev.glob->dummy_read_page;
+
+        if (adev->dummy_page_addr)
                 return 0;
-        adev->dummy_page.page = alloc_page(GFP_DMA32 | GFP_KERNEL | __GFP_ZERO);
-        if (adev->dummy_page.page == NULL)
-                return -ENOMEM;
-        adev->dummy_page.addr = pci_map_page(adev->pdev, adev->dummy_page.page,
-                                        0, PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
-        if (pci_dma_mapping_error(adev->pdev, adev->dummy_page.addr)) {
+        adev->dummy_page_addr = pci_map_page(adev->pdev, dummy_page, 0,
+                                             PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+        if (pci_dma_mapping_error(adev->pdev, adev->dummy_page_addr)) {
                 dev_err(&adev->pdev->dev, "Failed to DMA MAP the dummy page\n");
-                __free_page(adev->dummy_page.page);
-                adev->dummy_page.page = NULL;
+                adev->dummy_page_addr = 0;
                 return -ENOMEM;
         }
         return 0;
@@ -93,12 +91,11 @@ static int amdgpu_gart_dummy_page_init(struct amdgpu_device *adev)
  */
 static void amdgpu_gart_dummy_page_fini(struct amdgpu_device *adev)
 {
-        if (adev->dummy_page.page == NULL)
+        if (!adev->dummy_page_addr)
                 return;
-        pci_unmap_page(adev->pdev, adev->dummy_page.addr,
-                        PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
-        __free_page(adev->dummy_page.page);
-        adev->dummy_page.page = NULL;
+        pci_unmap_page(adev->pdev, adev->dummy_page_addr,
+                       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+        adev->dummy_page_addr = 0;
 }
 
 /**
@@ -236,7 +233,7 @@ int amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
 #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
                 adev->gart.pages[p] = NULL;
 #endif
-                page_base = adev->dummy_page.addr;
+                page_base = adev->dummy_page_addr;
                 if (!adev->gart.ptr)
                         continue;
 
@@ -347,7 +344,7 @@ int amdgpu_gart_init(struct amdgpu_device *adev)
 {
         int r;
 
-        if (adev->dummy_page.page)
+        if (adev->dummy_page_addr)
                 return 0;
 
         /* We need PAGE_SIZE >= AMDGPU_GPU_PAGE_SIZE */