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author | Chris Wilson <chris@chris-wilson.co.uk> | 2012-06-01 15:20:22 +0100 |
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committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-09-20 14:22:57 +0200 |
commit | 9da3da660d8c19a54f6e93361d147509be3fff84 (patch) | |
tree | 3479ef13a733975a02dd679e3fc9ae0872e3be25 /drivers/gpu/drm/i915/i915_gem_tiling.c | |
parent | f60d7f0c1d55a935475ab394955cafddefaa6533 (diff) | |
download | op-kernel-dev-9da3da660d8c19a54f6e93361d147509be3fff84.zip op-kernel-dev-9da3da660d8c19a54f6e93361d147509be3fff84.tar.gz |
drm/i915: Replace the array of pages with a scatterlist
Rather than have multiple data structures for describing our page layout
in conjunction with the array of pages, we can migrate all users over to
a scatterlist.
One major advantage, other than unifying the page tracking structures,
this offers is that we replace the vmalloc'ed array (which can be up to
a megabyte in size) with a chain of individual pages which helps reduce
memory pressure.
The disadvantage is that we then do not have a simple array to iterate,
or to access randomly. The common case for this is in the relocation
processing, which will typically fit within a single scatterlist page
and so be almost the same cost as the simple array. For iterating over
the array, the extra function call could be optimised away, but in
reality is an insignificant cost of either binding the pages, or
performing the pwrite/pread.
v2: Fix drm_clflush_sg() to not invoke wbinvd as well! And fix the
trivial compile error from rebasing.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem_tiling.c')
-rw-r--r-- | drivers/gpu/drm/i915/i915_gem_tiling.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c index b964df5..8093ecd 100644 --- a/drivers/gpu/drm/i915/i915_gem_tiling.c +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c @@ -470,18 +470,20 @@ i915_gem_swizzle_page(struct page *page) void i915_gem_object_do_bit_17_swizzle(struct drm_i915_gem_object *obj) { + struct scatterlist *sg; int page_count = obj->base.size >> PAGE_SHIFT; int i; if (obj->bit_17 == NULL) return; - for (i = 0; i < page_count; i++) { - char new_bit_17 = page_to_phys(obj->pages[i]) >> 17; + for_each_sg(obj->pages->sgl, sg, page_count, i) { + struct page *page = sg_page(sg); + char new_bit_17 = page_to_phys(page) >> 17; if ((new_bit_17 & 0x1) != (test_bit(i, obj->bit_17) != 0)) { - i915_gem_swizzle_page(obj->pages[i]); - set_page_dirty(obj->pages[i]); + i915_gem_swizzle_page(page); + set_page_dirty(page); } } } @@ -489,6 +491,7 @@ i915_gem_object_do_bit_17_swizzle(struct drm_i915_gem_object *obj) void i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj) { + struct scatterlist *sg; int page_count = obj->base.size >> PAGE_SHIFT; int i; @@ -502,8 +505,9 @@ i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj) } } - for (i = 0; i < page_count; i++) { - if (page_to_phys(obj->pages[i]) & (1 << 17)) + for_each_sg(obj->pages->sgl, sg, page_count, i) { + struct page *page = sg_page(sg); + if (page_to_phys(page) & (1 << 17)) __set_bit(i, obj->bit_17); else __clear_bit(i, obj->bit_17); |