diff options
author | Nicolin Chen <b42378@freescale.com> | 2013-11-13 03:09:52 +0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-13 07:09:22 +0400 |
commit | 684f0d3d14f2744ae7ad79063b21909e32bf444e (patch) | |
tree | 0f09fcd01b3471b97bf611c6257f66afcf135fae /lib | |
parent | ff6092a8a413f3db1938b4606e078fa751ed6cdb (diff) |
lib/genalloc: add a helper function for DMA buffer allocation
When using pool space for DMA buffer, there might be duplicated calling of
gen_pool_alloc() and gen_pool_virt_to_phys() in each implementation.
Thus it's better to add a simple helper function, a compatible one to the
common dma_alloc_coherent(), to save some code.
Signed-off-by: Nicolin Chen <b42378@freescale.com>
Cc: "Hans J. Koch" <hjk@hansjkoch.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/genalloc.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/lib/genalloc.c b/lib/genalloc.c index 26cf20be72b7..dda31168844f 100644 --- a/lib/genalloc.c +++ b/lib/genalloc.c @@ -313,6 +313,34 @@ retry: EXPORT_SYMBOL(gen_pool_alloc); /** + * gen_pool_dma_alloc - allocate special memory from the pool for DMA usage + * @pool: pool to allocate from + * @size: number of bytes to allocate from the pool + * @dma: dma-view physical address + * + * Allocate the requested number of bytes from the specified pool. + * Uses the pool allocation function (with first-fit algorithm by default). + * Can not be used in NMI handler on architectures without + * NMI-safe cmpxchg implementation. + */ +void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma) +{ + unsigned long vaddr; + + if (!pool) + return NULL; + + vaddr = gen_pool_alloc(pool, size); + if (!vaddr) + return NULL; + + *dma = gen_pool_virt_to_phys(pool, vaddr); + + return (void *)vaddr; +} +EXPORT_SYMBOL(gen_pool_dma_alloc); + +/** * gen_pool_free - free allocated special memory back to the pool * @pool: pool to free to * @addr: starting address of memory to free back to pool |