drm: Fix for non-coherent DMA PowerPC

This patch fixes bits of the DRM so to make the radeon DRI work on
non-cache coherent PCI DMA variants of the PowerPC processors.

It moves the few places that needs change to wrappers to that
other architectures with similar issues can easily add their
own changes to those wrappers, at least until we have more useful
generic kernel API.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 30 insertions, 6 deletions

diff --git a/linux-core/ati_pcigart.c b/linux-core/ati_pcigart.c
index 68029635..93519e5f 100644
--- a/linux-core/ati_pcigart.c
+++ b/linux-core/ati_pcigart.c
@@ -224,6 +224,12 @@ int drm_ati_pcigart_init(struct drm_device *dev, struct drm_ati_pcigart_info *ga
 		}
 	}
 
+	if (gart_info->gart_table_location == DRM_ATI_GART_MAIN)
+		dma_sync_single_for_device(&dev->pdev->dev,
+					   bus_address,
+					   max_pages * sizeof(u32),
+					   PCI_DMA_TODEVICE);
+
 	ret = 1;
 
 #if defined(__i386__) || defined(__x86_64__)
diff --git a/linux-core/drm_scatter.c b/linux-core/drm_scatter.c
index 77b9f95d..dfae4b84 100644
--- a/linux-core/drm_scatter.c
+++ b/linux-core/drm_scatter.c
@@ -36,6 +36,15 @@
 
 #define DEBUG_SCATTER 0
 
+static inline void *drm_vmalloc_dma(unsigned long size)
+{
+#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
+	return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL | _PAGE_NO_CACHE);
+#else
+	return vmalloc_32(size);
+#endif
+}
+
 void drm_sg_cleanup(struct drm_sg_mem *entry)
 {
 	struct page *page;
@@ -105,7 +114,7 @@ int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
 	}
 	memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
 
-	entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
+	entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT);
 	if (!entry->virtual) {
 		drm_free(entry->busaddr,
 			 entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);
diff --git a/linux-core/drm_vm.c b/linux-core/drm_vm.c
index 15e1c0f5..ffda8284 100644
--- a/linux-core/drm_vm.c
+++ b/linux-core/drm_vm.c
@@ -59,17 +59,27 @@ pgprot_t drm_io_prot(uint32_t map_type, struct vm_area_struct *vma)
 	pgprot_val(tmp) |= _PAGE_NO_CACHE;
 	if (map_type == _DRM_REGISTERS)
 		pgprot_val(tmp) |= _PAGE_GUARDED;
-#endif
-#if defined(__ia64__)
+#elif defined(__ia64__)
 	if (efi_range_is_wc(vma->vm_start, vma->vm_end -
 				    vma->vm_start))
 		tmp = pgprot_writecombine(tmp);
 	else
 		tmp = pgprot_noncached(tmp);
+#elif defined(__sparc__)
+	tmp = pgprot_noncached(tmp);
 #endif
 	return tmp;
 }
 
+static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma)
+{
+	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
+
+#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
+	tmp |= _PAGE_NO_CACHE;
+#endif
+	return tmp;
+}
 
 /**
  * \c nopage method for AGP virtual memory.
@@ -628,9 +638,6 @@ static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
 		offset = dev->driver->get_reg_ofs(dev);
 		vma->vm_flags |= VM_IO;	/* not in core dump */
 		vma->vm_page_prot = drm_io_prot(map->type, vma);
-#ifdef __sparc__
-		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-#endif
 		if (io_remap_pfn_range(vma, vma->vm_start,
 				       (map->offset + offset) >> PAGE_SHIFT,
 				       vma->vm_end - vma->vm_start,
@@ -649,6 +656,7 @@ static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
 		    page_to_pfn(virt_to_page(map->handle)),
 		    vma->vm_end - vma->vm_start, vma->vm_page_prot))
 			return -EAGAIN;
+		vma->vm_page_prot = drm_dma_prot(map->type, vma);
 	/* fall through to _DRM_SHM */
 	case _DRM_SHM:
 		vma->vm_ops = &drm_vm_shm_ops;
@@ -661,6 +669,7 @@ static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
 		vma->vm_ops = &drm_vm_sg_ops;
 		vma->vm_private_data = (void *)map;
 		vma->vm_flags |= VM_RESERVED;
+		vma->vm_page_prot = drm_dma_prot(map->type, vma);
 		break;
 	case _DRM_TTM:
 		return drm_bo_mmap_locked(vma, filp, map);