linux-4.4.1/__dma_alloc()(arm) の変更点

• 追加された行はこの色です。
• 削除された行はこの色です。
• linux-4.4.1/__dma_alloc()(arm) へ行く。
• linux-4.4.1/__dma_alloc()(arm) の差分を削除

*参照元 [#g67f836d]
#backlinks

*説明 [#b144c45e]
-パス: [[linux-4.4.1/arch/arm/mm/dma-mapping.c]]

-FIXME: これは何？
--説明


**引数 [#i200bce6]
-struct device *dev
--
--[[linux-4.4.1/device]]
-size_t size
--
-dma_addr_t *handle
--
--[[linux-4.4.1/dma_addr_t]]
-gfp_t gfp
--
--[[linux-4.4.1/gfp_t]]
-pgprot_t prot
--
--[[linux-4.4.1/pgprot_t]]
-bool is_coherent
--
-struct dma_attrs *attrs
--
--[[linux-4.4.1/dma_attrs]]
-const void *caller
--


**返り値 [#y8721785]
-void *
--


**参考 [#u85ffe64]


*実装 [#j8654022]
 static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
                          gfp_t gfp, pgprot_t prot, bool is_coherent,
                          struct dma_attrs *attrs, const void *caller)
 {
         u64 mask = get_coherent_dma_mask(dev);
         struct page *page = NULL;
         void *addr;
         bool want_vaddr;
 
-
--[[linux-4.4.1/get_coherent_dma_mask()]]
--[[linux-4.4.1/page]]

 #ifdef CONFIG_DMA_API_DEBUG
-
--[[linux-4.4.1/CONFIG_DMA_API_DEBUG]]

         u64 limit = (mask + 1) & ~mask;
         if (limit && size >= limit) {
                 dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n",
                         size, mask);
-
--[[linux-4.4.1/dev_warn()]]

                 return NULL;
         }
 #endif
 
         if (!mask)
                 return NULL;
 
         if (mask < 0xffffffffULL)
                 gfp |= GFP_DMA;
 
         /*
          * Following is a work-around (a.k.a. hack) to prevent pages
          * with __GFP_COMP being passed to split_page() which cannot
          * handle them.  The real problem is that this flag probably
          * should be 0 on ARM as it is not supported on this
          * platform; see CONFIG_HUGETLBFS.
          */
         gfp &= ~(__GFP_COMP);
 
         *handle = DMA_ERROR_CODE;
         size = PAGE_ALIGN(size);
         want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs);
 
-
--[[linux-4.4.1/PAGE_ALIGN()]]
--[[linux-4.4.1/dma_get_attr()]]

         if (nommu())
                 addr = __alloc_simple_buffer(dev, size, gfp, &page);
-
--[[linux-4.4.1/nommu()]]
--[[linux-4.4.1/__alloc_simple_buffer()]]

         else if (dev_get_cma_area(dev) && (gfp & __GFP_DIRECT_RECLAIM))
                 addr = __alloc_from_contiguous(dev, size, prot, &page,
                                                caller, want_vaddr);
-
--[[linux-4.4.1/dev_get_cma_area()]]
--[[linux-4.4.1/__alloc_from_contiguous()]]

         else if (is_coherent)
                 addr = __alloc_simple_buffer(dev, size, gfp, &page);
         else if (!gfpflags_allow_blocking(gfp))
                 addr = __alloc_from_pool(size, &page);
-
--[[linux-4.4.1/gfpflags_allow_blocking()]]
--[[linux-4.4.1/__alloc_from_pool()]]

         else
                 addr = __alloc_remap_buffer(dev, size, gfp, prot, &page,
                                             caller, want_vaddr);
 
-
--[[linux-4.4.1/__alloc_remap_buffer()]]

         if (page)
                 *handle = pfn_to_dma(dev, page_to_pfn(page));
 
-
--[[linux-4.4.1/pfn_to_dma()]]
--[[linux-4.4.1/page_to_pfn()]]

         return want_vaddr ? addr : page;
 }


*コメント [#g21e54ba]