/**
* arm_dma_map_page - map a portion of a page for streaming DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @page: page that buffer resides in
* @offset: offset into page for start of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* Ensure that any data held in the cache is appropriately discarded
* or written back.
*
* The device owns this memory once this call has completed. The CPU
* can regain ownership by calling dma_unmap_page().
*/
static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
__dma_page_cpu_to_dev(page, offset, size, dir);
return pfn_to_dma(dev, page_to_pfn(page)) + offset;
}
static void arm_dma_sync_single_for_device(struct device *dev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
unsigned int offset = handle & (PAGE_SIZE - 1);
struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
if (!arch_is_coherent())
__dma_page_cpu_to_dev(page, offset, size, dir);
}
/**
* arm_dma_map_page - map a portion of a page for streaming DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @page: page that buffer resides in
* @offset: offset into page for start of buffer
* @size: size of buffer to map
* @dir: DMA transfer direction
*
* Ensure that any data held in the cache is appropriately discarded
* or written back.
*
* The device owns this memory once this call has completed. The CPU
* can regain ownership by calling dma_unmap_page().
*/
static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
if (!arch_is_coherent())
__dma_page_cpu_to_dev(page, offset, size, dir);
return pfn_to_dma(dev, page_to_pfn(page)) + offset;
}
static void *ion_page_pool_alloc_pages(struct ion_page_pool *pool)
{
struct page *page = alloc_pages(pool->gfp_mask, pool->order);
if (!page)
return NULL;
/* this is only being used to flush the page for dma,
this api is not really suitable for calling from a driver
but no better way to flush a page for dma exist at this time */
__dma_page_cpu_to_dev(page, 0, PAGE_SIZE << pool->order,
DMA_BIDIRECTIONAL);
return page;
}
static inline dma_addr_t map_single_or_page(struct device *dev, void *ptr,
struct page *page, unsigned long offset, size_t size,
enum dma_data_direction dir)
{
struct dmabounce_device_info *device_info = dev->archdata.dmabounce;
dma_addr_t dma_addr;
int needs_bounce = 0;
if (device_info)
DO_STATS ( device_info->map_op_count++ );
if (page)
dma_addr = page_to_dma(dev, page) + offset;
else
dma_addr = virt_to_dma(dev, ptr);
if (dev->dma_mask) {
unsigned long mask = *dev->dma_mask;
unsigned long limit;
limit = (mask - 1) | mask;
limit = (limit + 1) & ~limit;
if (limit && size > limit) {
dev_err(dev, "DMA mapping too big (requested %#x "
"mask %#Lx)\n", size, *dev->dma_mask);
return ~0;
}
/*
* Figure out if we need to bounce from the DMA mask.
*/
needs_bounce = (dma_addr & ~mask) ||
(limit && (dma_addr + size > limit));
}
if (device_info && (needs_bounce || dma_needs_bounce(dev, dma_addr, size))) {
struct safe_buffer *buf;
buf = alloc_safe_buffer(device_info, ptr, page, offset, size, dir);
if (buf == 0) {
dev_err(dev, "%s: unable to map unsafe buffer %p!\n",
__func__, ptr);
return 0;
}
if (buf->page)
dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped "
"to %p (dma=%#x)\n", __func__,
page_address(buf->page),
page_to_dma(dev, buf->page),
buf->safe, buf->safe_dma_addr);
else
dev_dbg(dev, "%s: unsafe buffer %p (dma=%#x) mapped "
"to %p (dma=%#x)\n", __func__,
buf->ptr, virt_to_dma(dev, buf->ptr),
buf->safe, buf->safe_dma_addr);
if ((dir == DMA_TO_DEVICE) ||
(dir == DMA_BIDIRECTIONAL)) {
if (page)
ptr = kmap_atomic(page, KM_BOUNCE_READ) + offset;
dev_dbg(dev, "%s: copy unsafe %p to safe %p, size %d\n",
__func__, ptr, buf->safe, size);
memcpy(buf->safe, ptr, size);
wmb();
if (page)
kunmap_atomic(ptr - offset, KM_BOUNCE_READ);
}
dma_addr = buf->safe_dma_addr;
} else {
/*
* We don't need to sync the DMA buffer since
* it was allocated via the coherent allocators.
*/
if (page)
__dma_page_cpu_to_dev(page, offset, size, dir);
else
__dma_single_cpu_to_dev(ptr, size, dir);
}
return dma_addr;
}
