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Commit 2a3eeba8 authored by Magnus Damm's avatar Magnus Damm Committed by Paul Mundt
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sh: declared coherent memory support V2 fix 



This patch fixes the recently introduced declared coherent memory support.
Without this fix a cached memory area is returned by dma_alloc_coherent() -
unless dma_declare_coherent_memory() has setup a separate area.

This patch makes sure an uncached memory area is returned. With this patch
it is now possible to ping through an rtl8139 interface on r2d-plus.

Signed-off-by: default avatarMagnus Damm <damm@igel.co.jp>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent e760e716

arch/sh/mm/consistent.c

+20 −12
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ struct dma_coherent_mem { 
void *dma_alloc_coherent(struct device *dev, size_t size,

			   dma_addr_t *dma_handle, gfp_t gfp)

{

	void *ret;

	void *ret, *ret_nocache;

	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;

	int order = get_order(size);
@@ -44,17 +44,24 @@ void *dma_alloc_coherent(struct device *dev, size_t size, 
	}



	ret = (void *)__get_free_pages(gfp, order);

	if (!ret)

		return NULL;



	if (ret != NULL) {

	memset(ret, 0, size);

	/*

	 * Pages from the page allocator may have data present in

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

	 */

		dma_cache_sync(NULL, ret, size, DMA_BIDIRECTIONAL);

		*dma_handle = virt_to_phys(ret);

	dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);



	ret_nocache = ioremap_nocache(virt_to_phys(ret), size);

	if (!ret_nocache) {

		free_pages((unsigned long)ret, order);

		return NULL;

	}

	return ret;



	*dma_handle = virt_to_phys(ret);

	return ret_nocache;

}

EXPORT_SYMBOL(dma_alloc_coherent);
@@ -71,7 +78,8 @@ void dma_free_coherent(struct device *dev, size_t size, 
	} else {

		WARN_ON(irqs_disabled());	/* for portability */

		BUG_ON(mem && mem->flags & DMA_MEMORY_EXCLUSIVE);

		free_pages((unsigned long)vaddr, order);

		free_pages((unsigned long)phys_to_virt(dma_handle), order);

		iounmap(vaddr);

	}

}

EXPORT_SYMBOL(dma_free_coherent);