drm: Add GEM ("graphics execution manager") to i915 driver.

GEM allows the creation of persistent buffer objects accessible by the
graphics device through new ioctls for managing execution of commands on the
device.  The userland API is almost entirely driver-specific to ensure that
any driver building on this model can easily map the interface to individual
driver requirements.

GEM is used by the 2d driver for managing its internal state allocations and
will be used for pixmap storage to reduce memory consumption and enable
zero-copy GLX_EXT_texture_from_pixmap, and in the 3d driver is used to enable
GL_EXT_framebuffer_object and GL_ARB_pixel_buffer_object.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 50 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_agpsupport.c b/drivers/gpu/drm/drm_agpsupport.c
index aefa5ac..2639be2 100644
--- a/drivers/gpu/drm/drm_agpsupport.c
+++ b/drivers/gpu/drm/drm_agpsupport.c
@@ -33,6 +33,7 @@
 
 #include "drmP.h"
 #include <linux/module.h>
+#include <asm/agp.h>
 
 #if __OS_HAS_AGP
 
@@ -452,4 +453,52 @@ int drm_agp_unbind_memory(DRM_AGP_MEM * handle)
 	return agp_unbind_memory(handle);
 }
 
-#endif				/* __OS_HAS_AGP */
+/**
+ * Binds a collection of pages into AGP memory at the given offset, returning
+ * the AGP memory structure containing them.
+ *
+ * No reference is held on the pages during this time -- it is up to the
+ * caller to handle that.
+ */
+DRM_AGP_MEM *
+drm_agp_bind_pages(struct drm_device *dev,
+		   struct page **pages,
+		   unsigned long num_pages,
+		   uint32_t gtt_offset)
+{
+	DRM_AGP_MEM *mem;
+	int ret, i;
+
+	DRM_DEBUG("\n");
+
+	mem = drm_agp_allocate_memory(dev->agp->bridge, num_pages,
+				      AGP_USER_MEMORY);
+	if (mem == NULL) {
+		DRM_ERROR("Failed to allocate memory for %ld pages\n",
+			  num_pages);
+		return NULL;
+	}
+
+	for (i = 0; i < num_pages; i++)
+		mem->memory[i] = phys_to_gart(page_to_phys(pages[i]));
+	mem->page_count = num_pages;
+
+	mem->is_flushed = true;
+	ret = drm_agp_bind_memory(mem, gtt_offset / PAGE_SIZE);
+	if (ret != 0) {
+		DRM_ERROR("Failed to bind AGP memory: %d\n", ret);
+		agp_free_memory(mem);
+		return NULL;
+	}
+
+	return mem;
+}
+EXPORT_SYMBOL(drm_agp_bind_pages);
+
+void drm_agp_chipset_flush(struct drm_device *dev)
+{
+	agp_flush_chipset(dev->agp->bridge);
+}
+EXPORT_SYMBOL(drm_agp_chipset_flush);
+
+#endif /* __OS_HAS_AGP */