Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
dma-coherent: add documentation to new interfaces
Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
authored by Dmitry Baryshkov and committed by Ingo Molnar b6d4f7e3 8fa8b9fb
+28
kernel/dma-coherent.c
+28
kernel/dma-coherent.c
···
92
92
}
93
93
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
94
94
95
+
/**
96
+
* Try to allocate memory from the per-device coherent area.
97
+
*
98
+
* @dev: device from which we allocate memory
99
+
* @size: size of requested memory area
100
+
* @dma_handle: This will be filled with the correct dma handle
101
+
* @ret: This pointer will be filled with the virtual address
102
+
* to allocated area.
103
+
*
104
+
* This function should be only called from per-arch %dma_alloc_coherent()
105
+
* to support allocation from per-device coherent memory pools.
106
+
*
107
+
* Returns 0 if dma_alloc_coherent should continue with allocating from
108
+
* generic memory areas, or !0 if dma_alloc_coherent should return %ret.
109
+
*/
95
110
int dma_alloc_from_coherent(struct device *dev, ssize_t size,
96
111
dma_addr_t *dma_handle, void **ret)
97
112
{
···
126
111
return (mem != NULL);
127
112
}
128
113
114
+
/**
115
+
* Try to free the memory allocated from per-device coherent memory pool.
116
+
* @dev: device from which the memory was allocated
117
+
* @order: the order of pages allocated
118
+
* @vaddr: virtual address of allocated pages
119
+
*
120
+
* This checks whether the memory was allocated from the per-device
121
+
* coherent memory pool and if so, releases that memory.
122
+
*
123
+
* Returns 1 if we correctly released the memory, or 0 if
124
+
* %dma_release_coherent() should proceed with releasing memory from
125
+
* generic pools.
126
+
*/
129
127
int dma_release_from_coherent(struct device *dev, int order, void *vaddr)
130
128
{
131
129
struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;