![Alexander Duyck](/assets/img/avatar_default.png)
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it later via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113457.76501.77603.stgit@ahduyck-blue-test.jf.intel.com Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
170 lines
3.9 KiB
C
170 lines
3.9 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*/
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#undef DEBUG
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#include <linux/dma-mapping.h>
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/scatterlist.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/export.h>
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#include <asm/pgalloc.h>
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#if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
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static void *m68k_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
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gfp_t flag, unsigned long attrs)
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{
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struct page *page, **map;
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pgprot_t pgprot;
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void *addr;
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int i, order;
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pr_debug("dma_alloc_coherent: %d,%x\n", size, flag);
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size = PAGE_ALIGN(size);
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order = get_order(size);
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page = alloc_pages(flag, order);
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if (!page)
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return NULL;
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*handle = page_to_phys(page);
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map = kmalloc(sizeof(struct page *) << order, flag & ~__GFP_DMA);
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if (!map) {
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__free_pages(page, order);
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return NULL;
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}
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split_page(page, order);
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order = 1 << order;
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size >>= PAGE_SHIFT;
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map[0] = page;
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for (i = 1; i < size; i++)
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map[i] = page + i;
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for (; i < order; i++)
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__free_page(page + i);
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pgprot = __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
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if (CPU_IS_040_OR_060)
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pgprot_val(pgprot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S;
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else
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pgprot_val(pgprot) |= _PAGE_NOCACHE030;
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addr = vmap(map, size, VM_MAP, pgprot);
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kfree(map);
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return addr;
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}
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static void m68k_dma_free(struct device *dev, size_t size, void *addr,
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dma_addr_t handle, unsigned long attrs)
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{
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pr_debug("dma_free_coherent: %p, %x\n", addr, handle);
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vfree(addr);
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}
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#else
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#include <asm/cacheflush.h>
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static void *m68k_dma_alloc(struct device *dev, size_t size,
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dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
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{
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void *ret;
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/* ignore region specifiers */
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gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
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if (dev == NULL || (*dev->dma_mask < 0xffffffff))
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gfp |= GFP_DMA;
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ret = (void *)__get_free_pages(gfp, get_order(size));
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if (ret != NULL) {
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memset(ret, 0, size);
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*dma_handle = virt_to_phys(ret);
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}
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return ret;
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}
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static void m68k_dma_free(struct device *dev, size_t size, void *vaddr,
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dma_addr_t dma_handle, unsigned long attrs)
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{
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free_pages((unsigned long)vaddr, get_order(size));
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}
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#endif /* CONFIG_MMU && !CONFIG_COLDFIRE */
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static void m68k_dma_sync_single_for_device(struct device *dev,
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dma_addr_t handle, size_t size, enum dma_data_direction dir)
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{
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switch (dir) {
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case DMA_BIDIRECTIONAL:
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case DMA_TO_DEVICE:
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cache_push(handle, size);
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break;
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case DMA_FROM_DEVICE:
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cache_clear(handle, size);
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break;
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default:
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if (printk_ratelimit())
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printk("dma_sync_single_for_device: unsupported dir %u\n", dir);
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break;
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}
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}
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static void m68k_dma_sync_sg_for_device(struct device *dev,
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struct scatterlist *sglist, int nents, enum dma_data_direction dir)
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{
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int i;
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struct scatterlist *sg;
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for_each_sg(sglist, sg, nents, i) {
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dma_sync_single_for_device(dev, sg->dma_address, sg->length,
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dir);
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}
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}
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static dma_addr_t m68k_dma_map_page(struct device *dev, struct page *page,
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unsigned long offset, size_t size, enum dma_data_direction dir,
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unsigned long attrs)
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{
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dma_addr_t handle = page_to_phys(page) + offset;
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if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
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dma_sync_single_for_device(dev, handle, size, dir);
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return handle;
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}
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static int m68k_dma_map_sg(struct device *dev, struct scatterlist *sglist,
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int nents, enum dma_data_direction dir, unsigned long attrs)
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{
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int i;
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struct scatterlist *sg;
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for_each_sg(sglist, sg, nents, i) {
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sg->dma_address = sg_phys(sg);
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if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
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continue;
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dma_sync_single_for_device(dev, sg->dma_address, sg->length,
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dir);
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}
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return nents;
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}
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struct dma_map_ops m68k_dma_ops = {
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.alloc = m68k_dma_alloc,
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.free = m68k_dma_free,
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.map_page = m68k_dma_map_page,
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.map_sg = m68k_dma_map_sg,
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.sync_single_for_device = m68k_dma_sync_single_for_device,
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.sync_sg_for_device = m68k_dma_sync_sg_for_device,
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};
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EXPORT_SYMBOL(m68k_dma_ops);
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