Merge tag 'drm-for-v4.16' of git://people.freedesktop.org/~airlied/linux

[linux.git] / drivers / gpu / drm / amd / amdgpu / amdgpu_gart.c

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
index 1f51897acc5b4d7bcf0b86fa7e2c53accff60d49..0a4f34afaaaa321dc2a0680a227660d8ecefd0d3 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
@@ -56,6 +56,51 @@
  * Common GART table functions.
  */
 
+/**
+ * amdgpu_dummy_page_init - init dummy page used by the driver
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Allocate the dummy page used by the driver (all asics).
+ * This dummy page is used by the driver as a filler for gart entries
+ * when pages are taken out of the GART
+ * Returns 0 on sucess, -ENOMEM on failure.
+ */
+static int amdgpu_gart_dummy_page_init(struct amdgpu_device *adev)
+{
+       if (adev->dummy_page.page)
+               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)) {
+               dev_err(&adev->pdev->dev, "Failed to DMA MAP the dummy page\n");
+               __free_page(adev->dummy_page.page);
+               adev->dummy_page.page = NULL;
+               return -ENOMEM;
+       }
+       return 0;
+}
+
+/**
+ * amdgpu_dummy_page_fini - free dummy page used by the driver
+ *
+ * @adev: amdgpu_device pointer
+ *
+ * Frees the dummy page used by the driver (all asics).
+ */
+static void amdgpu_gart_dummy_page_fini(struct amdgpu_device *adev)
+{
+       if (adev->dummy_page.page == NULL)
+               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;
+}
+
 /**
  * amdgpu_gart_table_vram_alloc - allocate vram for gart page table
  *
@@ -308,7 +353,7 @@ int amdgpu_gart_init(struct amdgpu_device *adev)
                DRM_ERROR("Page size is smaller than GPU page size!\n");
                return -EINVAL;
        }
-       r = amdgpu_dummy_page_init(adev);
+       r = amdgpu_gart_dummy_page_init(adev);
        if (r)
                return r;
        /* Compute table size */
@@ -340,5 +385,5 @@ void amdgpu_gart_fini(struct amdgpu_device *adev)
        vfree(adev->gart.pages);
        adev->gart.pages = NULL;
 #endif
-       amdgpu_dummy_page_fini(adev);
+       amdgpu_gart_dummy_page_fini(adev);
 }