[PATCH 1/8] gma500: add the ability to request backed space or not

From: Alan Cox
Date: Tue Apr 19 2011 - 10:48:17 EST


We will will need this for doing a GEM allocator. It should also avoid any
crashes with the current code if the stolen area is too small.

Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---

drivers/staging/gma500/psb_fb.c | 4 ++--
drivers/staging/gma500/psb_gtt.c | 17 ++++++++++++++---
drivers/staging/gma500/psb_gtt.h | 2 +-
3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/gma500/psb_fb.c b/drivers/staging/gma500/psb_fb.c
index 0bad4e0..e06365b 100644
--- a/drivers/staging/gma500/psb_fb.c
+++ b/drivers/staging/gma500/psb_fb.c
@@ -479,8 +479,8 @@ static int psbfb_create(struct psb_fbdev *fbdev,
size = mode_cmd.pitch * mode_cmd.height;
aligned_size = ALIGN(size, PAGE_SIZE);

- /* Allocate the framebuffer in the GTT */
- backing = psb_gtt_alloc_range(dev, aligned_size, "fb");
+ /* Allocate the framebuffer in the GTT with stolen page backing */
+ backing = psb_gtt_alloc_range(dev, aligned_size, "fb", 1);
if (backing == NULL)
return -ENOMEM;

diff --git a/drivers/staging/gma500/psb_gtt.c b/drivers/staging/gma500/psb_gtt.c
index a97e7be..69323f9 100644
--- a/drivers/staging/gma500/psb_gtt.c
+++ b/drivers/staging/gma500/psb_gtt.c
@@ -972,6 +972,7 @@ struct gtt_range *psb_gtt_lookup_handle(struct drm_device *dev, int handle)
* @dev: Our DRM device
* @len: length (bytes) of address space required
* @name: resource name
+ * @backed: resource should be backed by stolen pages
*
* Ask the kernel core to find us a suitable range of addresses
* to use for a GTT mapping.
@@ -981,12 +982,23 @@ struct gtt_range *psb_gtt_lookup_handle(struct drm_device *dev, int handle)
* as in use.
*/
struct gtt_range *psb_gtt_alloc_range(struct drm_device *dev, int len,
- const char *name)
+ const char *name, int backed)
{
struct drm_psb_private *dev_priv = dev->dev_private;
struct gtt_range *gt;
struct resource *r = dev_priv->gtt_mem;
int ret;
+ unsigned long start, end;
+
+ if (backed) {
+ /* The start of the GTT is the stolen pages */
+ start = r->start;
+ end = r->start + dev_priv->pg->stolen_size - 1;
+ } else {
+ /* The rest we will use for GEM backed objects */
+ start = r->start + dev_priv->pg->stolen_size;
+ end = -1;
+ }

gt = kzalloc(sizeof(struct gtt_range), GFP_KERNEL);
if (gt == NULL)
@@ -996,8 +1008,7 @@ struct gtt_range *psb_gtt_alloc_range(struct drm_device *dev, int len,
kref_init(&gt->kref);

ret = allocate_resource(dev_priv->gtt_mem, &gt->resource,
- len, 0, -1, /*r->start, r->end - 1, */
- PAGE_SIZE, NULL, NULL);
+ len, start, end, PAGE_SIZE, NULL, NULL);
if (ret == 0) {
gt->offset = gt->resource.start - r->start;
return gt;
diff --git a/drivers/staging/gma500/psb_gtt.h b/drivers/staging/gma500/psb_gtt.h
index 010ef70..dc2259c 100644
--- a/drivers/staging/gma500/psb_gtt.h
+++ b/drivers/staging/gma500/psb_gtt.h
@@ -105,7 +105,7 @@ extern int psb_gtt_release_handle(struct drm_device *dev, struct gtt_range *gt);
extern struct gtt_range *psb_gtt_lookup_handle(struct drm_device *dev,
int handle);
extern struct gtt_range *psb_gtt_alloc_range(struct drm_device *dev, int len,
- const char *name);
+ const char *name, int backed);
extern void psb_gtt_kref_put(struct gtt_range *gt);
extern void psb_gtt_free_range(struct drm_device *dev, struct gtt_range *gt);


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