forked from luck/tmp_suning_uos_patched
iommu: Implement common IOMMU ops for DMA mapping
Taking inspiration from the existing arch/arm code, break out some generic functions to interface the DMA-API to the IOMMU-API. This will do the bulk of the heavy lifting for IOMMU-backed dma-mapping. Since associating an IOVA allocator with an IOMMU domain is a fairly common need, rather than introduce yet another private structure just to do this for ourselves, extend the top-level struct iommu_domain with the notion. A simple opaque cookie allows reuse by other IOMMU API users with their various different incompatible allocator types. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Robin Murphy
Joerg Roedel
parent
25cb62b764
commit
0db2e5d18f
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@ -49,6 +49,13 @@ config OF_IOMMU
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def_bool y
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depends on OF && IOMMU_API
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# IOMMU-agnostic DMA-mapping layer
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config IOMMU_DMA
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bool
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depends on NEED_SG_DMA_LENGTH
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select IOMMU_API
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select IOMMU_IOVA
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config FSL_PAMU
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bool "Freescale IOMMU support"
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depends on PPC32
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@ -1,6 +1,7 @@
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obj-$(CONFIG_IOMMU_API) += iommu.o
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obj-$(CONFIG_IOMMU_API) += iommu-traces.o
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obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o
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obj-$(CONFIG_IOMMU_DMA) += dma-iommu.o
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obj-$(CONFIG_IOMMU_IO_PGTABLE) += io-pgtable.o
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obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE) += io-pgtable-arm.o
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obj-$(CONFIG_IOMMU_IOVA) += iova.o
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524
drivers/iommu/dma-iommu.c
Normal file
524
drivers/iommu/dma-iommu.c
Normal file
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@ -0,0 +1,524 @@
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/*
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* A fairly generic DMA-API to IOMMU-API glue layer.
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*
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* Copyright (C) 2014-2015 ARM Ltd.
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*
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* based in part on arch/arm/mm/dma-mapping.c:
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* Copyright (C) 2000-2004 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/device.h>
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#include <linux/dma-iommu.h>
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#include <linux/huge_mm.h>
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#include <linux/iommu.h>
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#include <linux/iova.h>
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#include <linux/mm.h>
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int iommu_dma_init(void)
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{
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return iova_cache_get();
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}
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/**
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* iommu_get_dma_cookie - Acquire DMA-API resources for a domain
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* @domain: IOMMU domain to prepare for DMA-API usage
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*
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* IOMMU drivers should normally call this from their domain_alloc
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* callback when domain->type == IOMMU_DOMAIN_DMA.
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*/
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int iommu_get_dma_cookie(struct iommu_domain *domain)
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{
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struct iova_domain *iovad;
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if (domain->iova_cookie)
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return -EEXIST;
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iovad = kzalloc(sizeof(*iovad), GFP_KERNEL);
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domain->iova_cookie = iovad;
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return iovad ? 0 : -ENOMEM;
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}
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EXPORT_SYMBOL(iommu_get_dma_cookie);
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/**
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* iommu_put_dma_cookie - Release a domain's DMA mapping resources
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* @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
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*
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* IOMMU drivers should normally call this from their domain_free callback.
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*/
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void iommu_put_dma_cookie(struct iommu_domain *domain)
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{
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struct iova_domain *iovad = domain->iova_cookie;
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if (!iovad)
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return;
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put_iova_domain(iovad);
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kfree(iovad);
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domain->iova_cookie = NULL;
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}
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EXPORT_SYMBOL(iommu_put_dma_cookie);
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/**
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* iommu_dma_init_domain - Initialise a DMA mapping domain
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* @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
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* @base: IOVA at which the mappable address space starts
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* @size: Size of IOVA space
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*
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* @base and @size should be exact multiples of IOMMU page granularity to
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* avoid rounding surprises. If necessary, we reserve the page at address 0
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* to ensure it is an invalid IOVA. It is safe to reinitialise a domain, but
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* any change which could make prior IOVAs invalid will fail.
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*/
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int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size)
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{
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struct iova_domain *iovad = domain->iova_cookie;
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unsigned long order, base_pfn, end_pfn;
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if (!iovad)
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return -ENODEV;
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/* Use the smallest supported page size for IOVA granularity */
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order = __ffs(domain->ops->pgsize_bitmap);
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base_pfn = max_t(unsigned long, 1, base >> order);
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end_pfn = (base + size - 1) >> order;
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/* Check the domain allows at least some access to the device... */
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if (domain->geometry.force_aperture) {
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if (base > domain->geometry.aperture_end ||
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base + size <= domain->geometry.aperture_start) {
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pr_warn("specified DMA range outside IOMMU capability\n");
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return -EFAULT;
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}
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/* ...then finally give it a kicking to make sure it fits */
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base_pfn = max_t(unsigned long, base_pfn,
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domain->geometry.aperture_start >> order);
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end_pfn = min_t(unsigned long, end_pfn,
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domain->geometry.aperture_end >> order);
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}
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/* All we can safely do with an existing domain is enlarge it */
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if (iovad->start_pfn) {
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if (1UL << order != iovad->granule ||
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base_pfn != iovad->start_pfn ||
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end_pfn < iovad->dma_32bit_pfn) {
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pr_warn("Incompatible range for DMA domain\n");
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return -EFAULT;
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}
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iovad->dma_32bit_pfn = end_pfn;
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} else {
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init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn);
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}
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return 0;
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}
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EXPORT_SYMBOL(iommu_dma_init_domain);
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/**
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* dma_direction_to_prot - Translate DMA API directions to IOMMU API page flags
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* @dir: Direction of DMA transfer
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* @coherent: Is the DMA master cache-coherent?
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*
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* Return: corresponding IOMMU API page protection flags
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*/
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int dma_direction_to_prot(enum dma_data_direction dir, bool coherent)
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{
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int prot = coherent ? IOMMU_CACHE : 0;
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switch (dir) {
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case DMA_BIDIRECTIONAL:
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return prot | IOMMU_READ | IOMMU_WRITE;
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case DMA_TO_DEVICE:
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return prot | IOMMU_READ;
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case DMA_FROM_DEVICE:
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return prot | IOMMU_WRITE;
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default:
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return 0;
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}
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}
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static struct iova *__alloc_iova(struct iova_domain *iovad, size_t size,
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dma_addr_t dma_limit)
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{
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unsigned long shift = iova_shift(iovad);
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unsigned long length = iova_align(iovad, size) >> shift;
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/*
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* Enforce size-alignment to be safe - there could perhaps be an
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* attribute to control this per-device, or at least per-domain...
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*/
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return alloc_iova(iovad, length, dma_limit >> shift, true);
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}
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/* The IOVA allocator knows what we mapped, so just unmap whatever that was */
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static void __iommu_dma_unmap(struct iommu_domain *domain, dma_addr_t dma_addr)
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{
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struct iova_domain *iovad = domain->iova_cookie;
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unsigned long shift = iova_shift(iovad);
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unsigned long pfn = dma_addr >> shift;
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struct iova *iova = find_iova(iovad, pfn);
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size_t size;
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if (WARN_ON(!iova))
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return;
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size = iova_size(iova) << shift;
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size -= iommu_unmap(domain, pfn << shift, size);
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/* ...and if we can't, then something is horribly, horribly wrong */
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WARN_ON(size > 0);
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__free_iova(iovad, iova);
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}
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static void __iommu_dma_free_pages(struct page **pages, int count)
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{
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while (count--)
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__free_page(pages[count]);
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kvfree(pages);
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}
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static struct page **__iommu_dma_alloc_pages(unsigned int count, gfp_t gfp)
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{
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struct page **pages;
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unsigned int i = 0, array_size = count * sizeof(*pages);
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if (array_size <= PAGE_SIZE)
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pages = kzalloc(array_size, GFP_KERNEL);
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else
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pages = vzalloc(array_size);
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if (!pages)
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return NULL;
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/* IOMMU can map any pages, so himem can also be used here */
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gfp |= __GFP_NOWARN | __GFP_HIGHMEM;
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while (count) {
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struct page *page = NULL;
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int j, order = __fls(count);
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/*
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* Higher-order allocations are a convenience rather
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* than a necessity, hence using __GFP_NORETRY until
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* falling back to single-page allocations.
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*/
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for (order = min(order, MAX_ORDER); order > 0; order--) {
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page = alloc_pages(gfp | __GFP_NORETRY, order);
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if (!page)
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continue;
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if (PageCompound(page)) {
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if (!split_huge_page(page))
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break;
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__free_pages(page, order);
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} else {
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split_page(page, order);
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break;
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}
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}
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if (!page)
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page = alloc_page(gfp);
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if (!page) {
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__iommu_dma_free_pages(pages, i);
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return NULL;
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}
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j = 1 << order;
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count -= j;
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while (j--)
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pages[i++] = page++;
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}
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return pages;
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}
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/**
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* iommu_dma_free - Free a buffer allocated by iommu_dma_alloc()
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* @dev: Device which owns this buffer
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* @pages: Array of buffer pages as returned by iommu_dma_alloc()
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* @size: Size of buffer in bytes
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* @handle: DMA address of buffer
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*
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* Frees both the pages associated with the buffer, and the array
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* describing them
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*/
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void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
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dma_addr_t *handle)
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{
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__iommu_dma_unmap(iommu_get_domain_for_dev(dev), *handle);
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__iommu_dma_free_pages(pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
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*handle = DMA_ERROR_CODE;
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}
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/**
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* iommu_dma_alloc - Allocate and map a buffer contiguous in IOVA space
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* @dev: Device to allocate memory for. Must be a real device
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* attached to an iommu_dma_domain
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* @size: Size of buffer in bytes
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* @gfp: Allocation flags
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* @prot: IOMMU mapping flags
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* @handle: Out argument for allocated DMA handle
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* @flush_page: Arch callback which must ensure PAGE_SIZE bytes from the
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* given VA/PA are visible to the given non-coherent device.
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*
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* If @size is less than PAGE_SIZE, then a full CPU page will be allocated,
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* but an IOMMU which supports smaller pages might not map the whole thing.
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*
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* Return: Array of struct page pointers describing the buffer,
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* or NULL on failure.
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*/
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struct page **iommu_dma_alloc(struct device *dev, size_t size,
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gfp_t gfp, int prot, dma_addr_t *handle,
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void (*flush_page)(struct device *, const void *, phys_addr_t))
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{
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struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
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struct iova_domain *iovad = domain->iova_cookie;
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struct iova *iova;
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struct page **pages;
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struct sg_table sgt;
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dma_addr_t dma_addr;
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unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
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*handle = DMA_ERROR_CODE;
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pages = __iommu_dma_alloc_pages(count, gfp);
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if (!pages)
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return NULL;
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iova = __alloc_iova(iovad, size, dev->coherent_dma_mask);
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if (!iova)
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goto out_free_pages;
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size = iova_align(iovad, size);
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if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL))
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goto out_free_iova;
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if (!(prot & IOMMU_CACHE)) {
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struct sg_mapping_iter miter;
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/*
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* The CPU-centric flushing implied by SG_MITER_TO_SG isn't
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* sufficient here, so skip it by using the "wrong" direction.
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*/
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sg_miter_start(&miter, sgt.sgl, sgt.orig_nents, SG_MITER_FROM_SG);
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while (sg_miter_next(&miter))
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flush_page(dev, miter.addr, page_to_phys(miter.page));
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sg_miter_stop(&miter);
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}
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dma_addr = iova_dma_addr(iovad, iova);
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if (iommu_map_sg(domain, dma_addr, sgt.sgl, sgt.orig_nents, prot)
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< size)
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goto out_free_sg;
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*handle = dma_addr;
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sg_free_table(&sgt);
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return pages;
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out_free_sg:
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sg_free_table(&sgt);
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out_free_iova:
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__free_iova(iovad, iova);
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out_free_pages:
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__iommu_dma_free_pages(pages, count);
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return NULL;
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}
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/**
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* iommu_dma_mmap - Map a buffer into provided user VMA
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* @pages: Array representing buffer from iommu_dma_alloc()
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* @size: Size of buffer in bytes
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* @vma: VMA describing requested userspace mapping
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*
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* Maps the pages of the buffer in @pages into @vma. The caller is responsible
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* for verifying the correct size and protection of @vma beforehand.
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*/
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int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma)
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{
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unsigned long uaddr = vma->vm_start;
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unsigned int i, count = PAGE_ALIGN(size) >> PAGE_SHIFT;
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int ret = -ENXIO;
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for (i = vma->vm_pgoff; i < count && uaddr < vma->vm_end; i++) {
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ret = vm_insert_page(vma, uaddr, pages[i]);
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if (ret)
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break;
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uaddr += PAGE_SIZE;
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}
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return ret;
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}
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dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
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unsigned long offset, size_t size, int prot)
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{
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dma_addr_t dma_addr;
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struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
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struct iova_domain *iovad = domain->iova_cookie;
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phys_addr_t phys = page_to_phys(page) + offset;
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size_t iova_off = iova_offset(iovad, phys);
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size_t len = iova_align(iovad, size + iova_off);
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struct iova *iova = __alloc_iova(iovad, len, dma_get_mask(dev));
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if (!iova)
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return DMA_ERROR_CODE;
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dma_addr = iova_dma_addr(iovad, iova);
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if (iommu_map(domain, dma_addr, phys - iova_off, len, prot)) {
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__free_iova(iovad, iova);
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return DMA_ERROR_CODE;
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}
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return dma_addr + iova_off;
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}
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void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
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enum dma_data_direction dir, struct dma_attrs *attrs)
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{
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__iommu_dma_unmap(iommu_get_domain_for_dev(dev), handle);
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}
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/*
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* Prepare a successfully-mapped scatterlist to give back to the caller.
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* Handling IOVA concatenation can come later, if needed
|
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*/
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static int __finalise_sg(struct device *dev, struct scatterlist *sg, int nents,
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dma_addr_t dma_addr)
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{
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struct scatterlist *s;
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int i;
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for_each_sg(sg, s, nents, i) {
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/* Un-swizzling the fields here, hence the naming mismatch */
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unsigned int s_offset = sg_dma_address(s);
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unsigned int s_length = sg_dma_len(s);
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unsigned int s_dma_len = s->length;
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s->offset = s_offset;
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s->length = s_length;
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sg_dma_address(s) = dma_addr + s_offset;
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dma_addr += s_dma_len;
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}
|
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return i;
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}
|
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|
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/*
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* If mapping failed, then just restore the original list,
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* but making sure the DMA fields are invalidated.
|
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*/
|
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static void __invalidate_sg(struct scatterlist *sg, int nents)
|
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{
|
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struct scatterlist *s;
|
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int i;
|
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|
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for_each_sg(sg, s, nents, i) {
|
||||
if (sg_dma_address(s) != DMA_ERROR_CODE)
|
||||
s->offset = sg_dma_address(s);
|
||||
if (sg_dma_len(s))
|
||||
s->length = sg_dma_len(s);
|
||||
sg_dma_address(s) = DMA_ERROR_CODE;
|
||||
sg_dma_len(s) = 0;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* The DMA API client is passing in a scatterlist which could describe
|
||||
* any old buffer layout, but the IOMMU API requires everything to be
|
||||
* aligned to IOMMU pages. Hence the need for this complicated bit of
|
||||
* impedance-matching, to be able to hand off a suitably-aligned list,
|
||||
* but still preserve the original offsets and sizes for the caller.
|
||||
*/
|
||||
int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
|
||||
int nents, int prot)
|
||||
{
|
||||
struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
|
||||
struct iova_domain *iovad = domain->iova_cookie;
|
||||
struct iova *iova;
|
||||
struct scatterlist *s, *prev = NULL;
|
||||
dma_addr_t dma_addr;
|
||||
size_t iova_len = 0;
|
||||
int i;
|
||||
|
||||
/*
|
||||
* Work out how much IOVA space we need, and align the segments to
|
||||
* IOVA granules for the IOMMU driver to handle. With some clever
|
||||
* trickery we can modify the list in-place, but reversibly, by
|
||||
* hiding the original data in the as-yet-unused DMA fields.
|
||||
*/
|
||||
for_each_sg(sg, s, nents, i) {
|
||||
size_t s_offset = iova_offset(iovad, s->offset);
|
||||
size_t s_length = s->length;
|
||||
|
||||
sg_dma_address(s) = s->offset;
|
||||
sg_dma_len(s) = s_length;
|
||||
s->offset -= s_offset;
|
||||
s_length = iova_align(iovad, s_length + s_offset);
|
||||
s->length = s_length;
|
||||
|
||||
/*
|
||||
* The simple way to avoid the rare case of a segment
|
||||
* crossing the boundary mask is to pad the previous one
|
||||
* to end at a naturally-aligned IOVA for this one's size,
|
||||
* at the cost of potentially over-allocating a little.
|
||||
*/
|
||||
if (prev) {
|
||||
size_t pad_len = roundup_pow_of_two(s_length);
|
||||
|
||||
pad_len = (pad_len - iova_len) & (pad_len - 1);
|
||||
prev->length += pad_len;
|
||||
iova_len += pad_len;
|
||||
}
|
||||
|
||||
iova_len += s_length;
|
||||
prev = s;
|
||||
}
|
||||
|
||||
iova = __alloc_iova(iovad, iova_len, dma_get_mask(dev));
|
||||
if (!iova)
|
||||
goto out_restore_sg;
|
||||
|
||||
/*
|
||||
* We'll leave any physical concatenation to the IOMMU driver's
|
||||
* implementation - it knows better than we do.
|
||||
*/
|
||||
dma_addr = iova_dma_addr(iovad, iova);
|
||||
if (iommu_map_sg(domain, dma_addr, sg, nents, prot) < iova_len)
|
||||
goto out_free_iova;
|
||||
|
||||
return __finalise_sg(dev, sg, nents, dma_addr);
|
||||
|
||||
out_free_iova:
|
||||
__free_iova(iovad, iova);
|
||||
out_restore_sg:
|
||||
__invalidate_sg(sg, nents);
|
||||
return 0;
|
||||
}
|
||||
|
||||
void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
|
||||
enum dma_data_direction dir, struct dma_attrs *attrs)
|
||||
{
|
||||
/*
|
||||
* The scatterlist segments are mapped into a single
|
||||
* contiguous IOVA allocation, so this is incredibly easy.
|
||||
*/
|
||||
__iommu_dma_unmap(iommu_get_domain_for_dev(dev), sg_dma_address(sg));
|
||||
}
|
||||
|
||||
int iommu_dma_supported(struct device *dev, u64 mask)
|
||||
{
|
||||
/*
|
||||
* 'Special' IOMMUs which don't have the same addressing capability
|
||||
* as the CPU will have to wait until we have some way to query that
|
||||
* before they'll be able to use this framework.
|
||||
*/
|
||||
return 1;
|
||||
}
|
||||
|
||||
int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
|
||||
{
|
||||
return dma_addr == DMA_ERROR_CODE;
|
||||
}
|
||||
85
include/linux/dma-iommu.h
Normal file
85
include/linux/dma-iommu.h
Normal file
|
|
@ -0,0 +1,85 @@
|
|||
/*
|
||||
* Copyright (C) 2014-2015 ARM Ltd.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
#ifndef __DMA_IOMMU_H
|
||||
#define __DMA_IOMMU_H
|
||||
|
||||
#ifdef __KERNEL__
|
||||
#include <asm/errno.h>
|
||||
|
||||
#ifdef CONFIG_IOMMU_DMA
|
||||
#include <linux/iommu.h>
|
||||
|
||||
int iommu_dma_init(void);
|
||||
|
||||
/* Domain management interface for IOMMU drivers */
|
||||
int iommu_get_dma_cookie(struct iommu_domain *domain);
|
||||
void iommu_put_dma_cookie(struct iommu_domain *domain);
|
||||
|
||||
/* Setup call for arch DMA mapping code */
|
||||
int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size);
|
||||
|
||||
/* General helpers for DMA-API <-> IOMMU-API interaction */
|
||||
int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
|
||||
|
||||
/*
|
||||
* These implement the bulk of the relevant DMA mapping callbacks, but require
|
||||
* the arch code to take care of attributes and cache maintenance
|
||||
*/
|
||||
struct page **iommu_dma_alloc(struct device *dev, size_t size,
|
||||
gfp_t gfp, int prot, dma_addr_t *handle,
|
||||
void (*flush_page)(struct device *, const void *, phys_addr_t));
|
||||
void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
|
||||
dma_addr_t *handle);
|
||||
|
||||
int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma);
|
||||
|
||||
dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
|
||||
unsigned long offset, size_t size, int prot);
|
||||
int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
|
||||
int nents, int prot);
|
||||
|
||||
/*
|
||||
* Arch code with no special attribute handling may use these
|
||||
* directly as DMA mapping callbacks for simplicity
|
||||
*/
|
||||
void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
|
||||
enum dma_data_direction dir, struct dma_attrs *attrs);
|
||||
void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
|
||||
enum dma_data_direction dir, struct dma_attrs *attrs);
|
||||
int iommu_dma_supported(struct device *dev, u64 mask);
|
||||
int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
|
||||
|
||||
#else
|
||||
|
||||
struct iommu_domain;
|
||||
|
||||
static inline int iommu_dma_init(void)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
|
||||
{
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
|
||||
{
|
||||
}
|
||||
|
||||
#endif /* CONFIG_IOMMU_DMA */
|
||||
#endif /* __KERNEL__ */
|
||||
#endif /* __DMA_IOMMU_H */
|
||||
|
|
@ -81,6 +81,7 @@ struct iommu_domain {
|
|||
iommu_fault_handler_t handler;
|
||||
void *handler_token;
|
||||
struct iommu_domain_geometry geometry;
|
||||
void *iova_cookie;
|
||||
};
|
||||
|
||||
enum iommu_cap {
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user