Commit 36746436 authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds
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intel-iommu: integrate DMA CMA 



This adds support for the DMA Contiguous Memory Allocator for
intel-iommu.  This change enables dma_alloc_coherent() to allocate big
contiguous memory.

It is achieved in the same way as nommu_dma_ops currently does, i.e.
trying to allocate memory by dma_alloc_from_contiguous() and
alloc_pages() is used as a fallback.

Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9c5a3621

drivers/iommu/intel-iommu.c

+25 −8
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 
#include <linux/dmi.h>

#include <linux/pci-ats.h>

#include <linux/memblock.h>

#include <linux/dma-contiguous.h>

#include <asm/irq_remapping.h>

#include <asm/cacheflush.h>

#include <asm/iommu.h>
@@ -3193,7 +3194,7 @@ static void *intel_alloc_coherent(struct device *dev, size_t size, 
				  dma_addr_t *dma_handle, gfp_t flags,

				  struct dma_attrs *attrs)

{

	void *vaddr;

	struct page *page = NULL;

	int order;



	size = PAGE_ALIGN(size);
@@ -3208,17 +3209,31 @@ static void *intel_alloc_coherent(struct device *dev, size_t size, 
			flags |= GFP_DMA32;

	}



	vaddr = (void *)__get_free_pages(flags, order);

	if (!vaddr)

	if (flags & __GFP_WAIT) {

		unsigned int count = size >> PAGE_SHIFT;



		page = dma_alloc_from_contiguous(dev, count, order);

		if (page && iommu_no_mapping(dev) &&

		    page_to_phys(page) + size > dev->coherent_dma_mask) {

			dma_release_from_contiguous(dev, page, count);

			page = NULL;

		}

	}



	if (!page)

		page = alloc_pages(flags, order);

	if (!page)

		return NULL;

	memset(vaddr, 0, size);

	memset(page_address(page), 0, size);



	*dma_handle = __intel_map_single(dev, virt_to_bus(vaddr), size,

	*dma_handle = __intel_map_single(dev, page_to_phys(page), size,

					 DMA_BIDIRECTIONAL,

					 dev->coherent_dma_mask);

	if (*dma_handle)

		return vaddr;

	free_pages((unsigned long)vaddr, order);

		return page_address(page);

	if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))

		__free_pages(page, order);



	return NULL;

}
@@ -3226,12 +3241,14 @@ static void intel_free_coherent(struct device *dev, size_t size, void *vaddr, 
				dma_addr_t dma_handle, struct dma_attrs *attrs)

{

	int order;

	struct page *page = virt_to_page(vaddr);



	size = PAGE_ALIGN(size);

	order = get_order(size);



	intel_unmap_page(dev, dma_handle, size, DMA_BIDIRECTIONAL, NULL);

	free_pages((unsigned long)vaddr, order);

	if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))

		__free_pages(page, order);

}



static void intel_unmap_sg(struct device *dev, struct scatterlist *sglist,

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