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drm/i915: Simplify guard logic for setup_scratch_page() 

Older gcc is complaining it can't follow the guards and thinks that
addr may be used uninitialised

In the process, we can simplify down to one loop,
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-131 (-131)
Function                                     old     new   delta
setup_scratch_page                           545     414    -131

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180129102840.19901-1-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2018-01-29 10:28:40 +00:00
parent 74c0167f8b
commit 7fb9ee5db2
1 changed files with 33 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
drivers/gpu/drm/i915/i915_gem_gtt.c
View File

@ -543,9 +543,7 @@ static void fill_page_dma_32(struct i915_address_space *vm,
static int
setup_scratch_page(struct i915_address_space *vm, gfp_t gfp)
{
struct page *page = NULL;
dma_addr_t addr;
int order;
unsigned long size;
/*
* In order to utilize 64K pages for an object with a size < 2M, we will
@ -559,48 +557,47 @@ setup_scratch_page(struct i915_address_space *vm, gfp_t gfp)
* TODO: we should really consider write-protecting the scratch-page and
* sharing between ppgtt
*/
size = I915_GTT_PAGE_SIZE_4K;
if (i915_vm_is_48bit(vm) &&
HAS_PAGE_SIZES(vm->i915, I915_GTT_PAGE_SIZE_64K)) {
order = get_order(I915_GTT_PAGE_SIZE_64K);
page = alloc_pages(gfp | __GFP_ZERO | __GFP_NOWARN, order);
if (page) {
addr = dma_map_page(vm->dma, page, 0,
I915_GTT_PAGE_SIZE_64K,
PCI_DMA_BIDIRECTIONAL);
if (unlikely(dma_mapping_error(vm->dma, addr))) {
__free_pages(page, order);
page = NULL;
}
if (!IS_ALIGNED(addr, I915_GTT_PAGE_SIZE_64K)) {
dma_unmap_page(vm->dma, addr,
I915_GTT_PAGE_SIZE_64K,
PCI_DMA_BIDIRECTIONAL);
__free_pages(page, order);
page = NULL;
}
}
size = I915_GTT_PAGE_SIZE_64K;
gfp |= __GFP_NOWARN;
}
gfp |= __GFP_ZERO | __GFP_RETRY_MAYFAIL;
if (!page) {
order = 0;
page = alloc_page(gfp | __GFP_ZERO);
do {
int order = get_order(size);
struct page *page;
dma_addr_t addr;
page = alloc_pages(gfp, order);
if (unlikely(!page))
return -ENOMEM;
goto skip;
addr = dma_map_page(vm->dma, page, 0, PAGE_SIZE,
addr = dma_map_page(vm->dma, page, 0, size,
PCI_DMA_BIDIRECTIONAL);
if (unlikely(dma_mapping_error(vm->dma, addr))) {
__free_page(page);
if (unlikely(dma_mapping_error(vm->dma, addr)))
goto free_page;
if (unlikely(!IS_ALIGNED(addr, size)))
goto unmap_page;
vm->scratch_page.page = page;
vm->scratch_page.daddr = addr;
vm->scratch_page.order = order;
return 0;
unmap_page:
dma_unmap_page(vm->dma, addr, size, PCI_DMA_BIDIRECTIONAL);
free_page:
__free_pages(page, order);
skip:
if (size == I915_GTT_PAGE_SIZE_4K)
return -ENOMEM;
}
}
vm->scratch_page.page = page;
vm->scratch_page.daddr = addr;
vm->scratch_page.order = order;
return 0;
size = I915_GTT_PAGE_SIZE_4K;
gfp &= ~__GFP_NOWARN;
} while (1);
}
static void cleanup_scratch_page(struct i915_address_space *vm)