__dma_alloc_from_coherent

Name:__dma_alloc_from_coherent

Proto:static void *__dma_alloc_from_coherent(struct device *dev, struct dma_coherent_mem *mem, ssize_t size, dma_addr_t *dma_handle)

Type:void

Parameter:

Type	Parameter	Name
struct device *	dev
struct dma_coherent_mem *	mem
ssize_t	size
dma_addr_t *	dma_handle

130

order = get_order - Determine the allocation order of a memory size*@size: The size for which to get the order* Determine the allocation order of a particular sized block of memory

135

spin_lock_irqsave( & spinlock, flags)

137

If Value for the false possibility is greater at compile time(size > (size << PAGE_SHIFT determines the page size )) Then Go to err

140

pageno = map_find_free_region - find a contiguous aligned mem region*@bitmap: array of unsigned longs corresponding to the bitmap*@bits: number of bits in the bitmap*@order: region size (log base 2 of number of bits) to find* Find a region of free (zero) bits in a

141

If Value for the false possibility is greater at compile time(pageno < 0) Then Go to err

147

dma_handle = dma_get_device_base(dev, mem) + (pageno << PAGE_SHIFT determines the page size )

148

ret = virt_base + (pageno << PAGE_SHIFT determines the page size )

149

spin_unlock_irqrestore( & spinlock, flags)

150

memset(ret, 0, size)

151

Return ret

152

err :

153

spin_unlock_irqrestore( & spinlock, flags)

154

Return NULL

**Caller**
Name	Describe
dma_alloc_from_dev_coherent	dma_alloc_from_dev_coherent() - allocate memory from device coherent pool@dev: device from which we allocate memory@size: size of requested memory area@dma_handle: This will be filled with the correct dma handle@ret: This pointer will be filled with
dma_alloc_from_global_coherent

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