intel-gtt: initialize our own scratch page
The intel gtt fake agp driver is the only agp driver to use dma
address remapping. So it makes sense to fold this code back into the
only user (and thus reduce the reliance on the agp code).
This patch does the first step by initializing (and remapping) the
scratch page in a new function intel_gtt_setup_scratch_page.
Unfortunately intel_gtt_cleanup had to move to avoid a forward
declaration. The new scratch page is not yet used, though.
v2: Refactor out scratch page teardown. Suggested by Chris Wilson on
irc. This makes it clear what's going on and results in a nice
symmetry between setup and teardown.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index 248ac5f..e386a44 100644
--- a/drivers/char/agp/intel-gtt.c
+++ b/drivers/char/agp/intel-gtt.c
@@ -35,6 +35,8 @@
*/
#ifdef CONFIG_DMAR
#define USE_PCI_DMA_API 1
+#else
+#define USE_PCI_DMA_API 0
#endif
/* Max amount of stolen space, anything above will be returned to Linux */
@@ -108,6 +110,8 @@
struct page *i8xx_page;
struct resource ifp_resource;
int resource_valid;
+ struct page *scratch_page;
+ dma_addr_t scratch_page_dma;
} intel_private;
#define INTEL_GTT_GEN intel_private.driver->gen
@@ -115,7 +119,7 @@
#define IS_PINEVIEW intel_private.driver->is_pineview
#define IS_IRONLAKE intel_private.driver->is_ironlake
-#ifdef USE_PCI_DMA_API
+#if USE_PCI_DMA_API
static int intel_agp_map_page(struct page *page, dma_addr_t *ret)
{
*ret = pci_map_page(intel_private.pcidev, page, 0,
@@ -540,6 +544,32 @@
return addr | bridge->driver->masks[type].mask;
}
+static int intel_gtt_setup_scratch_page(void)
+{
+ struct page *page;
+ dma_addr_t dma_addr;
+
+ page = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
+ if (page == NULL)
+ return -ENOMEM;
+ get_page(page);
+ set_pages_uc(page, 1);
+
+ if (USE_PCI_DMA_API && INTEL_GTT_GEN > 2) {
+ dma_addr = pci_map_page(intel_private.pcidev, page, 0,
+ PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+ if (pci_dma_mapping_error(intel_private.pcidev, dma_addr))
+ return -EINVAL;
+
+ intel_private.scratch_page_dma = dma_addr;
+ } else
+ intel_private.scratch_page_dma = page_to_phys(page);
+
+ intel_private.scratch_page = page;
+
+ return 0;
+}
+
static const struct aper_size_info_fixed const intel_fake_agp_sizes[] = {
{128, 32768, 5},
/* The 64M mode still requires a 128k gatt */
@@ -794,6 +824,29 @@
return aperture_size >> PAGE_SHIFT;
}
+static void intel_gtt_teardown_scratch_page(void)
+{
+ set_pages_wb(intel_private.scratch_page, 1);
+ pci_unmap_page(intel_private.pcidev, intel_private.scratch_page_dma,
+ PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+ put_page(intel_private.scratch_page);
+ __free_page(intel_private.scratch_page);
+}
+
+static void intel_gtt_cleanup(void)
+{
+ if (intel_private.i9xx_flush_page)
+ iounmap(intel_private.i9xx_flush_page);
+ if (intel_private.resource_valid)
+ release_resource(&intel_private.ifp_resource);
+ intel_private.ifp_resource.start = 0;
+ intel_private.resource_valid = 0;
+ iounmap(intel_private.gtt);
+ iounmap(intel_private.registers);
+
+ intel_gtt_teardown_scratch_page();
+}
+
static int intel_gtt_init(void)
{
u32 gtt_map_size;
@@ -825,6 +878,12 @@
return -ENOMEM;
}
+ ret = intel_gtt_setup_scratch_page();
+ if (ret != 0) {
+ intel_gtt_cleanup();
+ return ret;
+ }
+
return 0;
}
@@ -1174,18 +1233,6 @@
return 0;
}
-static void intel_gtt_cleanup(void)
-{
- if (intel_private.i9xx_flush_page)
- iounmap(intel_private.i9xx_flush_page);
- if (intel_private.resource_valid)
- release_resource(&intel_private.ifp_resource);
- intel_private.ifp_resource.start = 0;
- intel_private.resource_valid = 0;
- iounmap(intel_private.gtt);
- iounmap(intel_private.registers);
-}
-
static void intel_i915_chipset_flush(struct agp_bridge_data *bridge)
{
if (intel_private.i9xx_flush_page)
@@ -1416,7 +1463,7 @@
.agp_destroy_pages = agp_generic_destroy_pages,
.agp_type_to_mask_type = intel_i830_type_to_mask_type,
.chipset_flush = intel_i915_chipset_flush,
-#ifdef USE_PCI_DMA_API
+#if USE_PCI_DMA_API
.agp_map_page = intel_agp_map_page,
.agp_unmap_page = intel_agp_unmap_page,
.agp_map_memory = intel_agp_map_memory,
@@ -1449,7 +1496,7 @@
.agp_destroy_pages = agp_generic_destroy_pages,
.agp_type_to_mask_type = intel_i830_type_to_mask_type,
.chipset_flush = intel_i915_chipset_flush,
-#ifdef USE_PCI_DMA_API
+#if USE_PCI_DMA_API
.agp_map_page = intel_agp_map_page,
.agp_unmap_page = intel_agp_unmap_page,
.agp_map_memory = intel_agp_map_memory,
@@ -1482,7 +1529,7 @@
.agp_destroy_pages = agp_generic_destroy_pages,
.agp_type_to_mask_type = intel_gen6_type_to_mask_type,
.chipset_flush = intel_i915_chipset_flush,
-#ifdef USE_PCI_DMA_API
+#if USE_PCI_DMA_API
.agp_map_page = intel_agp_map_page,
.agp_unmap_page = intel_agp_unmap_page,
.agp_map_memory = intel_agp_map_memory,
@@ -1515,7 +1562,7 @@
.agp_destroy_pages = agp_generic_destroy_pages,
.agp_type_to_mask_type = intel_i830_type_to_mask_type,
.chipset_flush = intel_i915_chipset_flush,
-#ifdef USE_PCI_DMA_API
+#if USE_PCI_DMA_API
.agp_map_page = intel_agp_map_page,
.agp_unmap_page = intel_agp_unmap_page,
.agp_map_memory = intel_agp_map_memory,