lib/genalloc: add a helper function for DMA buffer allocation (684f0d3d) · Commits · 戴 / test

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>

include/linux/genalloc.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -94,6 +94,8 @@ static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr,
		}
		extern void gen_pool_destroy(struct gen_pool *);
		extern unsigned long gen_pool_alloc(struct gen_pool *, size_t);
		extern void gen_pool_dma_alloc(struct gen_pool pool, size_t size,
		dma_addr_t *dma);
		extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);
		extern void gen_pool_for_each_chunk(struct gen_pool *,
		void ()(struct gen_pool , struct gen_pool_chunk , void ), void *);

lib/genalloc.c

+28 −0

Original line number	Diff line number	Diff line
		@@ -312,6 +312,34 @@ 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

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