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drm/nv50: align size of buffer object to the right boundaries. 

- In the current situation the padding that is added is dangerous to write
  to, userspace could potentially overwrite parts of another bo.
- Depth and stencil buffers are supposed to be large enough in general so
  the waste of memory should be acceptable.
- Alternatives are hiding the padding from users or splitting vram into 2
  zones.

Signed-off-by: Maarten Maathuis <madman2003@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
hifive-unleashed-5.1
Maarten Maathuis 2009-12-27 12:22:07 +01:00 committed by Ben Skeggs
parent 5025b43120
commit eb1dba0eba
1 changed files with 5 additions and 5 deletions
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10
drivers/gpu/drm/nouveau/nouveau_bo.c
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@ -65,8 +65,10 @@ nouveau_bo_fixup_align(struct drm_device *dev,
/*
* Some of the tile_flags have a periodic structure of N*4096 bytes,
* align to to that as well as the page size. Overallocate memory to
* avoid corruption of other buffer objects.
* align to to that as well as the page size. Align the size to the
* appropriate boundaries. This does imply that sizes are rounded up
* 3-7 pages, so be aware of this and do not waste memory by allocating
* many small buffers.
*/
if (dev_priv->card_type == NV_50) {
uint32_t block_size = nouveau_mem_fb_amount(dev) >> 15;
@ -77,22 +79,20 @@ nouveau_bo_fixup_align(struct drm_device *dev,
case 0x2800:
case 0x4800:
case 0x7a00:
*size = roundup(*size, block_size);
if (is_power_of_2(block_size)) {
*size += 3 * block_size;
for (i = 1; i < 10; i++) {
*align = 12 * i * block_size;
if (!(*align % 65536))
break;
}
} else {
*size += 6 * block_size;
for (i = 1; i < 10; i++) {
*align = 8 * i * block_size;
if (!(*align % 65536))
break;
}
}
*size = roundup(*size, *align);
break;
default:
break;