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[ARM] dma: fix dmabounce dma_sync_xxx() implementations
The dmabounce dma_sync_xxx() implementation have been broken for quite some time; they all copy data between the DMA buffer and the CPU visible buffer no irrespective of the change of ownership. (IOW, a DMA_FROM_DEVICE mapping copies data from the DMA buffer to the CPU buffer during a call to dma_sync_single_for_device().) Fix it by getting rid of sync_single(), moving the contents into the recently created dmabounce_sync_for_xxx() functions and adjusting appropriately. This also makes it possible to properly support the DMA range sync functions. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King
Russell King
parent
8c8a0ec57e
commit
125ab12acf
@ -205,6 +205,21 @@ free_safe_buffer(struct dmabounce_device_info *device_info, struct safe_buffer *
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/* ************************************************** */
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static struct safe_buffer *find_safe_buffer_dev(struct device *dev,
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dma_addr_t dma_addr, const char *where)
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{
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if (!dev || !dev->archdata.dmabounce)
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return NULL;
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if (dma_mapping_error(dev, dma_addr)) {
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if (dev)
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dev_err(dev, "Trying to %s invalid mapping\n", where);
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else
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pr_err("unknown device: Trying to %s invalid mapping\n", where);
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return NULL;
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}
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return find_safe_buffer(dev->archdata.dmabounce, dma_addr);
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}
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static inline dma_addr_t
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map_single(struct device *dev, void *ptr, size_t size,
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enum dma_data_direction dir)
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@ -274,19 +289,7 @@ static inline void
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unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
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enum dma_data_direction dir)
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{
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struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
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struct safe_buffer *buf = NULL;
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/*
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* Trying to unmap an invalid mapping
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*/
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if (dma_mapping_error(dev, dma_addr)) {
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dev_err(dev, "Trying to unmap invalid mapping\n");
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return;
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}
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if (device_info)
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buf = find_safe_buffer(device_info, dma_addr);
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struct safe_buffer *buf = find_safe_buffer_dev(dev, dma_addr, "unmap");
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if (buf) {
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BUG_ON(buf->size != size);
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@ -296,7 +299,7 @@ unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
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__func__, buf->ptr, virt_to_dma(dev, buf->ptr),
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buf->safe, buf->safe_dma_addr);
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DO_STATS ( device_info->bounce_count++ );
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DO_STATS(dev->archdata.dmabounce->bounce_count++);
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if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) {
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void *ptr = buf->ptr;
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@ -317,74 +320,7 @@ unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
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dmac_clean_range(ptr, ptr + size);
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outer_clean_range(__pa(ptr), __pa(ptr) + size);
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}
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free_safe_buffer(device_info, buf);
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}
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}
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static int sync_single(struct device *dev, dma_addr_t dma_addr, size_t size,
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enum dma_data_direction dir)
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{
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struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
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struct safe_buffer *buf = NULL;
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if (device_info)
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buf = find_safe_buffer(device_info, dma_addr);
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if (buf) {
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/*
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* Both of these checks from original code need to be
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* commented out b/c some drivers rely on the following:
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*
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* 1) Drivers may map a large chunk of memory into DMA space
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* but only sync a small portion of it. Good example is
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* allocating a large buffer, mapping it, and then
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* breaking it up into small descriptors. No point
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* in syncing the whole buffer if you only have to
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* touch one descriptor.
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*
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* 2) Buffers that are mapped as DMA_BIDIRECTIONAL are
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* usually only synced in one dir at a time.
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*
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* See drivers/net/eepro100.c for examples of both cases.
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*
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* -ds
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*
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* BUG_ON(buf->size != size);
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* BUG_ON(buf->direction != dir);
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*/
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dev_dbg(dev,
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"%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n",
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__func__, buf->ptr, virt_to_dma(dev, buf->ptr),
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buf->safe, buf->safe_dma_addr);
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DO_STATS ( device_info->bounce_count++ );
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switch (dir) {
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case DMA_FROM_DEVICE:
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dev_dbg(dev,
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"%s: copy back safe %p to unsafe %p size %d\n",
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__func__, buf->safe, buf->ptr, size);
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memcpy(buf->ptr, buf->safe, size);
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break;
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case DMA_TO_DEVICE:
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dev_dbg(dev,
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"%s: copy out unsafe %p to safe %p, size %d\n",
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__func__,buf->ptr, buf->safe, size);
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memcpy(buf->safe, buf->ptr, size);
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break;
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case DMA_BIDIRECTIONAL:
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BUG(); /* is this allowed? what does it mean? */
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default:
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BUG();
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}
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/*
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* No need to sync the safe buffer - it was allocated
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* via the coherent allocators.
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*/
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return 0;
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} else {
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return 1;
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free_safe_buffer(dev->archdata.dmabounce, buf);
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}
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}
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@ -447,18 +383,54 @@ dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
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int dmabounce_sync_for_cpu(struct device *dev, dma_addr_t addr,
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unsigned long off, size_t sz, enum dma_data_direction dir)
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{
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dev_dbg(dev, "%s(dma=%#lx,off=%#lx,sz=%zx,dir=%x)\n",
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struct safe_buffer *buf;
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dev_dbg(dev, "%s(dma=%#x,off=%#lx,sz=%zx,dir=%x)\n",
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__func__, addr, off, sz, dir);
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return sync_single(dev, addr, off + sz, dir);
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buf = find_safe_buffer_dev(dev, addr, __func__);
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if (!buf)
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return 1;
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dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n",
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__func__, buf->ptr, virt_to_dma(dev, buf->ptr),
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buf->safe, buf->safe_dma_addr);
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DO_STATS(dev->archdata.dmabounce->bounce_count++);
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if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) {
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dev_dbg(dev, "%s: copy back safe %p to unsafe %p size %d\n",
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__func__, buf->safe + off, buf->ptr + off, sz);
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memcpy(buf->ptr + off, buf->safe + off, sz);
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}
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return 0;
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}
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EXPORT_SYMBOL(dmabounce_sync_for_cpu);
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int dmabounce_sync_for_device(struct device *dev, dma_addr_t addr,
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unsigned long off, size_t sz, enum dma_data_direction dir)
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{
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dev_dbg(dev, "%s(dma=%#lx,off=%#lx,sz=%zx,dir=%x)\n",
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struct safe_buffer *buf;
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dev_dbg(dev, "%s(dma=%#x,off=%#lx,sz=%zx,dir=%x)\n",
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__func__, addr, off, sz, dir);
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return sync_single(dev, addr, off + sz, dir);
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buf = find_safe_buffer_dev(dev, addr, __func__);
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if (!buf)
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return 1;
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dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped to %p (dma=%#x)\n",
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__func__, buf->ptr, virt_to_dma(dev, buf->ptr),
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buf->safe, buf->safe_dma_addr);
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DO_STATS(dev->archdata.dmabounce->bounce_count++);
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if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) {
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dev_dbg(dev, "%s: copy out unsafe %p to safe %p, size %d\n",
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__func__,buf->ptr + off, buf->safe + off, sz);
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memcpy(buf->safe + off, buf->ptr + off, sz);
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}
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return 0;
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}
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EXPORT_SYMBOL(dmabounce_sync_for_device);
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@ -241,6 +241,15 @@ extern void dmabounce_unregister_dev(struct device *);
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*/
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extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
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/*
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* The DMA API, implemented by dmabounce.c. See below for descriptions.
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*/
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extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
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extern dma_addr_t dma_map_page(struct device *dev, struct page *page,
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unsigned long offset, size_t size,
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enum dma_data_direction dir);
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extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
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/*
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* Private functions
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*/
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@ -251,7 +260,6 @@ int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
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#else
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#define dmabounce_sync_for_cpu(dev,dma,off,sz,dir) (1)
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#define dmabounce_sync_for_device(dev,dma,off,sz,dir) (1)
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#endif /* CONFIG_DMABOUNCE */
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/**
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@ -268,7 +276,6 @@ int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
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* can regain ownership by calling dma_unmap_single() or
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* dma_sync_single_for_cpu().
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*/
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#ifndef CONFIG_DMABOUNCE
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static inline dma_addr_t
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dma_map_single(struct device *dev, void *cpu_addr, size_t size,
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enum dma_data_direction dir)
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@ -278,9 +285,7 @@ dma_map_single(struct device *dev, void *cpu_addr, size_t size,
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return virt_to_dma(dev, cpu_addr);
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}
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#else
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extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
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#endif
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/**
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* dma_map_page - map a portion of a page for streaming DMA
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@ -297,7 +302,6 @@ extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_d
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* can regain ownership by calling dma_unmap_page() or
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* dma_sync_single_for_cpu().
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*/
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#ifndef CONFIG_DMABOUNCE
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static inline dma_addr_t
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dma_map_page(struct device *dev, struct page *page,
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unsigned long offset, size_t size,
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@ -308,11 +312,6 @@ dma_map_page(struct device *dev, struct page *page,
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return page_to_dma(dev, page) + offset;
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}
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#else
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extern dma_addr_t dma_map_page(struct device *dev, struct page *page,
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unsigned long offset, size_t size,
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enum dma_data_direction dir);
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#endif
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/**
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* dma_unmap_single - unmap a single buffer previously mapped
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@ -328,16 +327,13 @@ extern dma_addr_t dma_map_page(struct device *dev, struct page *page,
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* After this call, reads by the CPU to the buffer are guaranteed to see
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* whatever the device wrote there.
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*/
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#ifndef CONFIG_DMABOUNCE
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static inline void
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dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
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enum dma_data_direction dir)
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{
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/* nothing to do */
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}
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#else
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extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
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#endif
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#endif /* CONFIG_DMABOUNCE */
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/**
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* dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
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