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https://github.com/torvalds/linux
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![FUJITA Tomonori](/assets/img/avatar_default.png)
This patch converts PPC's IOMMU to use the IOMMU helper functions. The IOMMU doesn't allocate a memory area spanning LLD's segment boundary anymore. iseries_hv_alloc and iseries_hv_map don't have proper device struct. 4GB boundary is used for them. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Jeff Garzik <jeff@garzik.org> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
200 lines
5.6 KiB
C
200 lines
5.6 KiB
C
/*
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* Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
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*
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* Provide default implementations of the DMA mapping callbacks for
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* directly mapped busses and busses using the iommu infrastructure
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*/
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#include <linux/device.h>
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#include <linux/dma-mapping.h>
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#include <asm/bug.h>
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#include <asm/iommu.h>
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#include <asm/abs_addr.h>
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/*
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* Generic iommu implementation
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*/
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static inline unsigned long device_to_mask(struct device *dev)
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{
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if (dev->dma_mask && *dev->dma_mask)
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return *dev->dma_mask;
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/* Assume devices without mask can take 32 bit addresses */
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return 0xfffffffful;
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}
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/* Allocates a contiguous real buffer and creates mappings over it.
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* Returns the virtual address of the buffer and sets dma_handle
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* to the dma address (mapping) of the first page.
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*/
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static void *dma_iommu_alloc_coherent(struct device *dev, size_t size,
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dma_addr_t *dma_handle, gfp_t flag)
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{
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return iommu_alloc_coherent(dev, dev->archdata.dma_data, size,
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dma_handle, device_to_mask(dev), flag,
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dev->archdata.numa_node);
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}
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static void dma_iommu_free_coherent(struct device *dev, size_t size,
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void *vaddr, dma_addr_t dma_handle)
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{
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iommu_free_coherent(dev->archdata.dma_data, size, vaddr, dma_handle);
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}
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/* Creates TCEs for a user provided buffer. The user buffer must be
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* contiguous real kernel storage (not vmalloc). The address of the buffer
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* passed here is the kernel (virtual) address of the buffer. The buffer
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* need not be page aligned, the dma_addr_t returned will point to the same
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* byte within the page as vaddr.
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*/
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static dma_addr_t dma_iommu_map_single(struct device *dev, void *vaddr,
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size_t size,
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enum dma_data_direction direction)
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{
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return iommu_map_single(dev, dev->archdata.dma_data, vaddr, size,
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device_to_mask(dev), direction);
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}
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static void dma_iommu_unmap_single(struct device *dev, dma_addr_t dma_handle,
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size_t size,
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enum dma_data_direction direction)
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{
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iommu_unmap_single(dev->archdata.dma_data, dma_handle, size, direction);
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}
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static int dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
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int nelems, enum dma_data_direction direction)
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{
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return iommu_map_sg(dev, sglist, nelems,
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device_to_mask(dev), direction);
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}
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static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist,
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int nelems, enum dma_data_direction direction)
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{
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iommu_unmap_sg(dev->archdata.dma_data, sglist, nelems, direction);
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}
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/* We support DMA to/from any memory page via the iommu */
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static int dma_iommu_dma_supported(struct device *dev, u64 mask)
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{
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struct iommu_table *tbl = dev->archdata.dma_data;
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if (!tbl || tbl->it_offset > mask) {
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printk(KERN_INFO
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"Warning: IOMMU offset too big for device mask\n");
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if (tbl)
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printk(KERN_INFO
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"mask: 0x%08lx, table offset: 0x%08lx\n",
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mask, tbl->it_offset);
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else
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printk(KERN_INFO "mask: 0x%08lx, table unavailable\n",
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mask);
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return 0;
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} else
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return 1;
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}
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struct dma_mapping_ops dma_iommu_ops = {
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.alloc_coherent = dma_iommu_alloc_coherent,
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.free_coherent = dma_iommu_free_coherent,
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.map_single = dma_iommu_map_single,
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.unmap_single = dma_iommu_unmap_single,
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.map_sg = dma_iommu_map_sg,
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.unmap_sg = dma_iommu_unmap_sg,
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.dma_supported = dma_iommu_dma_supported,
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};
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EXPORT_SYMBOL(dma_iommu_ops);
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/*
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* Generic direct DMA implementation
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*
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* This implementation supports a per-device offset that can be applied if
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* the address at which memory is visible to devices is not 0. Platform code
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* can set archdata.dma_data to an unsigned long holding the offset. By
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* default the offset is zero.
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*/
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static unsigned long get_dma_direct_offset(struct device *dev)
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{
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return (unsigned long)dev->archdata.dma_data;
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}
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static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
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dma_addr_t *dma_handle, gfp_t flag)
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{
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struct page *page;
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void *ret;
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int node = dev->archdata.numa_node;
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page = alloc_pages_node(node, flag, get_order(size));
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if (page == NULL)
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return NULL;
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ret = page_address(page);
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memset(ret, 0, size);
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*dma_handle = virt_to_abs(ret) + get_dma_direct_offset(dev);
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return ret;
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}
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static void dma_direct_free_coherent(struct device *dev, size_t size,
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void *vaddr, dma_addr_t dma_handle)
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{
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free_pages((unsigned long)vaddr, get_order(size));
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}
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static dma_addr_t dma_direct_map_single(struct device *dev, void *ptr,
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size_t size,
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enum dma_data_direction direction)
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{
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return virt_to_abs(ptr) + get_dma_direct_offset(dev);
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}
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static void dma_direct_unmap_single(struct device *dev, dma_addr_t dma_addr,
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size_t size,
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enum dma_data_direction direction)
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{
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}
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static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
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int nents, enum dma_data_direction direction)
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{
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struct scatterlist *sg;
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int i;
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for_each_sg(sgl, sg, nents, i) {
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sg->dma_address = sg_phys(sg) + get_dma_direct_offset(dev);
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sg->dma_length = sg->length;
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}
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return nents;
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}
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static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
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int nents, enum dma_data_direction direction)
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{
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}
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static int dma_direct_dma_supported(struct device *dev, u64 mask)
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{
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/* Could be improved to check for memory though it better be
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* done via some global so platforms can set the limit in case
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* they have limited DMA windows
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*/
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return mask >= DMA_32BIT_MASK;
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}
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struct dma_mapping_ops dma_direct_ops = {
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.alloc_coherent = dma_direct_alloc_coherent,
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.free_coherent = dma_direct_free_coherent,
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.map_single = dma_direct_map_single,
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.unmap_single = dma_direct_unmap_single,
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.map_sg = dma_direct_map_sg,
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.unmap_sg = dma_direct_unmap_sg,
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.dma_supported = dma_direct_dma_supported,
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};
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EXPORT_SYMBOL(dma_direct_ops);
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