drm/amdgpu: add amdgpu_gart_map function v2

This allows us to write the mapped PTEs into
an IB instead of the table directly.

v2: fix build with debugfs enabled, remove unused assignment

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

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -570,6 +570,9 @@ int amdgpu_gart_init(struct amdgpu_device *adev);
 void amdgpu_gart_fini(struct amdgpu_device *adev);
 int amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
 			int pages);
+int amdgpu_gart_map(struct amdgpu_device *adev, uint64_t offset,
+		    int pages, dma_addr_t *dma_addr, uint64_t flags,
+		    void *dst);
 int amdgpu_gart_bind(struct amdgpu_device *adev, uint64_t offset,
 		     int pages, struct page **pagelist,
 		     dma_addr_t *dma_addr, uint64_t flags);

drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c

@@ -282,6 +282,41 @@ int amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
 	return 0;
 }
 
+/**
+ * amdgpu_gart_map - map dma_addresses into GART entries
+ *
+ * @adev: amdgpu_device pointer
+ * @offset: offset into the GPU's gart aperture
+ * @pages: number of pages to bind
+ * @dma_addr: DMA addresses of pages
+ *
+ * Map the dma_addresses into GART entries (all asics).
+ * Returns 0 for success, -EINVAL for failure.
+ */
+int amdgpu_gart_map(struct amdgpu_device *adev, uint64_t offset,
+		    int pages, dma_addr_t *dma_addr, uint64_t flags,
+		    void *dst)
+{
+	uint64_t page_base;
+	unsigned i, j, t;
+
+	if (!adev->gart.ready) {
+		WARN(1, "trying to bind memory to uninitialized GART !\n");
+		return -EINVAL;
+	}
+
+	t = offset / AMDGPU_GPU_PAGE_SIZE;
+
+	for (i = 0; i < pages; i++) {
+		page_base = dma_addr[i];
+		for (j = 0; j < (PAGE_SIZE / AMDGPU_GPU_PAGE_SIZE); j++, t++) {
+			amdgpu_gart_set_pte_pde(adev, dst, t, page_base, flags);
+			page_base += AMDGPU_GPU_PAGE_SIZE;
+		}
+	}
+	return 0;
+}
+
 /**
  * amdgpu_gart_bind - bind pages into the gart page table
  *
@@ -299,31 +334,30 @@ int amdgpu_gart_bind(struct amdgpu_device *adev, uint64_t offset,
 		     int pages, struct page **pagelist, dma_addr_t *dma_addr,
 		     uint64_t flags)
 {
-	unsigned t;
-	unsigned p;
-	uint64_t page_base;
-	int i, j;
+#ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
+	unsigned i,t,p;
+#endif
+	int r;
 
 	if (!adev->gart.ready) {
 		WARN(1, "trying to bind memory to uninitialized GART !\n");
 		return -EINVAL;
 	}
 
+#ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
 	t = offset / AMDGPU_GPU_PAGE_SIZE;
 	p = t / (PAGE_SIZE / AMDGPU_GPU_PAGE_SIZE);
-
-	for (i = 0; i < pages; i++, p++) {
-#ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
+	for (i = 0; i < pages; i++, p++)
 		adev->gart.pages[p] = pagelist[i];
 #endif
-		if (adev->gart.ptr) {
-			page_base = dma_addr[i];
-			for (j = 0; j < (PAGE_SIZE / AMDGPU_GPU_PAGE_SIZE); j++, t++) {
-				amdgpu_gart_set_pte_pde(adev, adev->gart.ptr, t, page_base, flags);
-				page_base += AMDGPU_GPU_PAGE_SIZE;
-			}
-		}
+
+	if (adev->gart.ptr) {
+		r = amdgpu_gart_map(adev, offset, pages, dma_addr, flags,
+			    adev->gart.ptr);
+		if (r)
+			return r;
 	}
+
 	mb();
 	amdgpu_gart_flush_gpu_tlb(adev, 0);
 	return 0;