[AVR32] Implement dma_{alloc,free}_writecombine()
Implement dma_alloc_writecombine() and its dma_free_writecombine() counterpart. These will do basically the same thing as dma_alloc_coherent() except that the virtual mapping will allow write buffering, causing better performance for certain use cases like frame buffers. The same API is already available on ARM. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
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@ -112,16 +112,21 @@ void dma_free_coherent(struct device *dev, size_t size,
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}
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}
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EXPORT_SYMBOL(dma_free_coherent);
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EXPORT_SYMBOL(dma_free_coherent);
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#if 0
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void *dma_alloc_writecombine(struct device *dev, size_t size,
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void *dma_alloc_writecombine(struct device *dev, size_t size,
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dma_addr_t *handle, gfp_t gfp)
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dma_addr_t *handle, gfp_t gfp)
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{
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{
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struct page *page;
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struct page *page;
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dma_addr_t phys;
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page = __dma_alloc(dev, size, handle, gfp);
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page = __dma_alloc(dev, size, handle, gfp);
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if (!page)
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return NULL;
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phys = page_to_phys(page);
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*handle = phys;
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/* Now, map the page into P3 with write-combining turned on */
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/* Now, map the page into P3 with write-combining turned on */
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return __ioremap(page_to_phys(page), size, _PAGE_BUFFER);
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return __ioremap(phys, size, _PAGE_BUFFER);
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}
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}
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EXPORT_SYMBOL(dma_alloc_writecombine);
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EXPORT_SYMBOL(dma_alloc_writecombine);
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@ -132,8 +137,7 @@ void dma_free_writecombine(struct device *dev, size_t size,
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iounmap(cpu_addr);
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iounmap(cpu_addr);
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page = bus_to_page(handle);
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page = phys_to_page(handle);
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__dma_free(dev, size, page, handle);
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__dma_free(dev, size, page, handle);
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}
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}
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EXPORT_SYMBOL(dma_free_writecombine);
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EXPORT_SYMBOL(dma_free_writecombine);
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#endif
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