Commit e0c6584d authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

sh: make dma_cache_sync a no-op 



sh does not implement DMA_ATTR_NON_CONSISTENT allocations, so it doesn't
make any sense to do any work in dma_cache_sync given that it
must be a no-op when dma_alloc_attrs returns coherent memory.

On the other hand sh uses dma_cache_sync internally in the dma_ops
implementation and for the maple bus that does not use the DMA API,
so a the old functionality for dma_cache_sync is still provided under
the name sh_sync_dma_for_device, and without the redundant dev
argument.  While at it two of the syncing dma_ops also go the proper
_for_device postfix.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
parent d708e71e

arch/sh/include/asm/dma-mapping.h

+7 −2
Original line number Diff line number Diff line
@@ -9,8 +9,10 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) 
	return dma_ops;

}



void dma_cache_sync(struct device *dev, void *vaddr, size_t size,

		    enum dma_data_direction dir);

static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,

		    enum dma_data_direction dir)

{

}



/* arch/sh/mm/consistent.c */

extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
@@ -20,4 +22,7 @@ extern void dma_generic_free_coherent(struct device *dev, size_t size, 
				      void *vaddr, dma_addr_t dma_handle,

				      unsigned long attrs);



void sh_sync_dma_for_device(void *vaddr, size_t size,

	    enum dma_data_direction dir);



#endif /* __ASM_SH_DMA_MAPPING_H */

arch/sh/kernel/dma-nommu.c

+9 −8
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
 */

#include <linux/dma-mapping.h>

#include <linux/io.h>

#include <asm/cacheflush.h>



static dma_addr_t nommu_map_page(struct device *dev, struct page *page,

				 unsigned long offset, size_t size,
@@ -20,7 +21,7 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page, 
	WARN_ON(size == 0);



	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		dma_cache_sync(dev, page_address(page) + offset, size, dir);

		sh_sync_dma_for_device(page_address(page) + offset, size, dir);



	return addr;

}
@@ -38,7 +39,7 @@ static int nommu_map_sg(struct device *dev, struct scatterlist *sg, 
		BUG_ON(!sg_page(s));



		if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))

			dma_cache_sync(dev, sg_virt(s), s->length, dir);

			sh_sync_dma_for_device(sg_virt(s), s->length, dir);



		s->dma_address = sg_phys(s);

		s->dma_length = s->length;
@@ -48,20 +49,20 @@ static int nommu_map_sg(struct device *dev, struct scatterlist *sg, 
}



#ifdef CONFIG_DMA_NONCOHERENT

static void nommu_sync_single(struct device *dev, dma_addr_t addr,

static void nommu_sync_single_for_device(struct device *dev, dma_addr_t addr,

			      size_t size, enum dma_data_direction dir)

{

	dma_cache_sync(dev, phys_to_virt(addr), size, dir);

	sh_sync_dma_for_device(phys_to_virt(addr), size, dir);

}



static void nommu_sync_sg(struct device *dev, struct scatterlist *sg,

static void nommu_sync_sg_for_device(struct device *dev, struct scatterlist *sg,

			  int nelems, enum dma_data_direction dir)

{

	struct scatterlist *s;

	int i;



	for_each_sg(sg, s, nelems, i)

		dma_cache_sync(dev, sg_virt(s), s->length, dir);

		sh_sync_dma_for_device(sg_virt(s), s->length, dir);

}

#endif
@@ -71,8 +72,8 @@ const struct dma_map_ops nommu_dma_ops = { 
	.map_page		= nommu_map_page,

	.map_sg			= nommu_map_sg,

#ifdef CONFIG_DMA_NONCOHERENT

	.sync_single_for_device	= nommu_sync_single,

	.sync_sg_for_device	= nommu_sync_sg,

	.sync_single_for_device	= nommu_sync_single_for_device,

	.sync_sg_for_device	= nommu_sync_sg_for_device,

#endif

	.is_phys		= 1,

};

arch/sh/mm/consistent.c

+3 −3
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size, 
	 * Pages from the page allocator may have data present in

	 * cache. So flush the cache before using uncached memory.

	 */

	dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);

	sh_sync_dma_for_device(ret, size, DMA_BIDIRECTIONAL);



	ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size);

	if (!ret_nocache) {
@@ -78,7 +78,7 @@ void dma_generic_free_coherent(struct device *dev, size_t size, 
	iounmap(vaddr);

}



void dma_cache_sync(struct device *dev, void *vaddr, size_t size,

void sh_sync_dma_for_device(void *vaddr, size_t size,

		    enum dma_data_direction direction)

{

	void *addr;
@@ -100,7 +100,7 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size, 
		BUG();

	}

}

EXPORT_SYMBOL(dma_cache_sync);

EXPORT_SYMBOL(sh_sync_dma_for_device);



static int __init memchunk_setup(char *str)

{

drivers/sh/maple/maple.c

+2 −3
Original line number Diff line number Diff line
@@ -300,7 +300,7 @@ static void maple_send(void) 
	mutex_unlock(&maple_wlist_lock);

	if (maple_packets > 0) {

		for (i = 0; i < (1 << MAPLE_DMA_PAGES); i++)

			dma_cache_sync(0, maple_sendbuf + i * PAGE_SIZE,

			sh_sync_dma_for_device(maple_sendbuf + i * PAGE_SIZE,

				       PAGE_SIZE, DMA_BIDIRECTIONAL);

	}
@@ -642,8 +642,7 @@ static void maple_dma_handler(struct work_struct *work) 
		list_for_each_entry_safe(mq, nmq, &maple_sentq, list) {

			mdev = mq->dev;

			recvbuf = mq->recvbuf->buf;

			dma_cache_sync(&mdev->dev, recvbuf, 0x400,

				DMA_FROM_DEVICE);

			sh_sync_dma_for_device(recvbuf, 0x400, DMA_FROM_DEVICE);

			code = recvbuf[0];

			kfree(mq->sendbuf);

			list_del_init(&mq->list);

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