665 lines · 17.7 KB · C
RawDownload
// SPDX-License-Identifier: GPL-2.0/* * Copyright (C) 2018-2020 Christoph Hellwig. * * DMA operations that map physical memory directly without using an IOMMU. */#include <linux/memblock.h> /* for max_pfn */#include <linux/export.h>#include <linux/mm.h>#include <linux/dma-map-ops.h>#include <linux/scatterlist.h>#include <linux/pfn.h>#include <linux/vmalloc.h>#include <linux/set_memory.h>#include <linux/slab.h>#include <linux/pci-p2pdma.h>#include "direct.h" /* * Most architectures use ZONE_DMA for the first 16 Megabytes, but some use * it for entirely different regions. In that case the arch code needs to * override the variable below for dma-direct to work properly. */u64 zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); static inline dma_addr_t phys_to_dma_direct(struct device *dev,		phys_addr_t phys){	if (force_dma_unencrypted(dev))		return phys_to_dma_unencrypted(dev, phys);	return phys_to_dma(dev, phys);} static inline struct page *dma_direct_to_page(struct device *dev,		dma_addr_t dma_addr){	return pfn_to_page(PHYS_PFN(dma_to_phys(dev, dma_addr)));} u64 dma_direct_get_required_mask(struct device *dev){	phys_addr_t phys = (phys_addr_t)(max_pfn - 1) << PAGE_SHIFT;	u64 max_dma = phys_to_dma_direct(dev, phys); 	return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;} static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 *phys_limit){	u64 dma_limit = min_not_zero(		dev->coherent_dma_mask,		dev->bus_dma_limit); 	/*	 * Optimistically try the zone that the physical address mask falls	 * into first.  If that returns memory that isn't actually addressable	 * we will fallback to the next lower zone and try again.	 *	 * Note that GFP_DMA32 and GFP_DMA are no ops without the corresponding	 * zones.	 */	*phys_limit = dma_to_phys(dev, dma_limit);	if (*phys_limit <= zone_dma_limit)		return GFP_DMA;	if (*phys_limit <= DMA_BIT_MASK(32))		return GFP_DMA32;	return 0;} bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size){	dma_addr_t dma_addr = phys_to_dma_direct(dev, phys); 	if (dma_addr == DMA_MAPPING_ERROR)		return false;	return dma_addr + size - 1 <=		min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);} static int dma_set_decrypted(struct device *dev, void *vaddr, size_t size){	if (!force_dma_unencrypted(dev))		return 0;	return set_memory_decrypted((unsigned long)vaddr, PFN_UP(size));} static int dma_set_encrypted(struct device *dev, void *vaddr, size_t size){	int ret; 	if (!force_dma_unencrypted(dev))		return 0;	ret = set_memory_encrypted((unsigned long)vaddr, PFN_UP(size));	if (ret)		pr_warn_ratelimited("leaking DMA memory that can't be re-encrypted\n");	return ret;} static void __dma_direct_free_pages(struct device *dev, struct page *page,				    size_t size){	if (swiotlb_free(dev, page, size))		return;	dma_free_contiguous(dev, page, size);} static struct page *dma_direct_alloc_swiotlb(struct device *dev, size_t size){	struct page *page = swiotlb_alloc(dev, size); 	if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {		swiotlb_free(dev, page, size);		return NULL;	} 	return page;} static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,		gfp_t gfp, bool allow_highmem){	int node = dev_to_node(dev);	struct page *page;	u64 phys_limit; 	WARN_ON_ONCE(!PAGE_ALIGNED(size)); 	if (is_swiotlb_for_alloc(dev))		return dma_direct_alloc_swiotlb(dev, size); 	gfp |= dma_direct_optimal_gfp_mask(dev, &phys_limit);	page = dma_alloc_contiguous(dev, size, gfp);	if (page) {		if (dma_coherent_ok(dev, page_to_phys(page), size) &&		    (allow_highmem || !PageHighMem(page)))			return page; 		dma_free_contiguous(dev, page, size);	} 	while ((page = alloc_pages_node(node, gfp, get_order(size)))	       && !dma_coherent_ok(dev, page_to_phys(page), size)) {		__free_pages(page, get_order(size)); 		if (IS_ENABLED(CONFIG_ZONE_DMA32) &&		    phys_limit < DMA_BIT_MASK(64) &&		    !(gfp & (GFP_DMA32 | GFP_DMA)))			gfp |= GFP_DMA32;		else if (IS_ENABLED(CONFIG_ZONE_DMA) && !(gfp & GFP_DMA))			gfp = (gfp & ~GFP_DMA32) | GFP_DMA;		else			return NULL;	} 	return page;} /* * Check if a potentially blocking operations needs to dip into the atomic * pools for the given device/gfp. */static bool dma_direct_use_pool(struct device *dev, gfp_t gfp){	return !gfpflags_allow_blocking(gfp) && !is_swiotlb_for_alloc(dev);} static void *dma_direct_alloc_from_pool(struct device *dev, size_t size,		dma_addr_t *dma_handle, gfp_t gfp){	struct page *page;	u64 phys_limit;	void *ret; 	if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_DMA_COHERENT_POOL)))		return NULL; 	gfp |= dma_direct_optimal_gfp_mask(dev, &phys_limit);	page = dma_alloc_from_pool(dev, size, &ret, gfp, dma_coherent_ok);	if (!page)		return NULL;	*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));	return ret;} static void *dma_direct_alloc_no_mapping(struct device *dev, size_t size,		dma_addr_t *dma_handle, gfp_t gfp){	struct page *page; 	page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO, true);	if (!page)		return NULL; 	/* remove any dirty cache lines on the kernel alias */	if (!PageHighMem(page))		arch_dma_prep_coherent(page, size); 	/* return the page pointer as the opaque cookie */	*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));	return page;} void *dma_direct_alloc(struct device *dev, size_t size,		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs){	bool remap = false, set_uncached = false;	struct page *page;	void *ret; 	size = PAGE_ALIGN(size);	if (attrs & DMA_ATTR_NO_WARN)		gfp |= __GFP_NOWARN; 	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&	    !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev))		return dma_direct_alloc_no_mapping(dev, size, dma_handle, gfp); 	if (!dev_is_dma_coherent(dev)) {		if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_ALLOC) &&		    !is_swiotlb_for_alloc(dev))			return arch_dma_alloc(dev, size, dma_handle, gfp,					      attrs); 		/*		 * If there is a global pool, always allocate from it for		 * non-coherent devices.		 */		if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL))			return dma_alloc_from_global_coherent(dev, size,					dma_handle); 		/*		 * Otherwise we require the architecture to either be able to		 * mark arbitrary parts of the kernel direct mapping uncached,		 * or remapped it uncached.		 */		set_uncached = IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED);		remap = IS_ENABLED(CONFIG_DMA_DIRECT_REMAP);		if (!set_uncached && !remap) {			pr_warn_once("coherent DMA allocations not supported on this platform.\n");			return NULL;		}	} 	/*	 * Remapping or decrypting memory may block, allocate the memory from	 * the atomic pools instead if we aren't allowed block.	 */	if ((remap || force_dma_unencrypted(dev)) &&	    dma_direct_use_pool(dev, gfp))		return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); 	/* we always manually zero the memory once we are done */	page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO, true);	if (!page)		return NULL; 	/*	 * dma_alloc_contiguous can return highmem pages depending on a	 * combination the cma= arguments and per-arch setup.  These need to be	 * remapped to return a kernel virtual address.	 */	if (PageHighMem(page)) {		remap = true;		set_uncached = false;	} 	if (remap) {		pgprot_t prot = dma_pgprot(dev, PAGE_KERNEL, attrs); 		if (force_dma_unencrypted(dev))			prot = pgprot_decrypted(prot); 		/* remove any dirty cache lines on the kernel alias */		arch_dma_prep_coherent(page, size); 		/* create a coherent mapping */		ret = dma_common_contiguous_remap(page, size, prot,				__builtin_return_address(0));		if (!ret)			goto out_free_pages;	} else {		ret = page_address(page);		if (dma_set_decrypted(dev, ret, size))			goto out_leak_pages;	} 	memset(ret, 0, size); 	if (set_uncached) {		arch_dma_prep_coherent(page, size);		ret = arch_dma_set_uncached(ret, size);		if (IS_ERR(ret))			goto out_encrypt_pages;	} 	*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));	return ret; out_encrypt_pages:	if (dma_set_encrypted(dev, page_address(page), size))		return NULL;out_free_pages:	__dma_direct_free_pages(dev, page, size);	return NULL;out_leak_pages:	return NULL;} void dma_direct_free(struct device *dev, size_t size,		void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs){	unsigned int page_order = get_order(size); 	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&	    !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) {		/* cpu_addr is a struct page cookie, not a kernel address */		dma_free_contiguous(dev, cpu_addr, size);		return;	} 	if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_ALLOC) &&	    !dev_is_dma_coherent(dev) &&	    !is_swiotlb_for_alloc(dev)) {		arch_dma_free(dev, size, cpu_addr, dma_addr, attrs);		return;	} 	if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) &&	    !dev_is_dma_coherent(dev)) {		if (!dma_release_from_global_coherent(page_order, cpu_addr))			WARN_ON_ONCE(1);		return;	} 	/* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */	if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&	    dma_free_from_pool(dev, cpu_addr, PAGE_ALIGN(size)))		return; 	if (is_vmalloc_addr(cpu_addr)) {		vunmap(cpu_addr);	} else {		if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_CLEAR_UNCACHED))			arch_dma_clear_uncached(cpu_addr, size);		if (dma_set_encrypted(dev, cpu_addr, size))			return;	} 	__dma_direct_free_pages(dev, dma_direct_to_page(dev, dma_addr), size);} struct page *dma_direct_alloc_pages(struct device *dev, size_t size,		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp){	struct page *page;	void *ret; 	if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp))		return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); 	page = __dma_direct_alloc_pages(dev, size, gfp, false);	if (!page)		return NULL; 	ret = page_address(page);	if (dma_set_decrypted(dev, ret, size))		goto out_leak_pages;	memset(ret, 0, size);	*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));	return page;out_leak_pages:	return NULL;} void dma_direct_free_pages(struct device *dev, size_t size,		struct page *page, dma_addr_t dma_addr,		enum dma_data_direction dir){	void *vaddr = page_address(page); 	/* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */	if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&	    dma_free_from_pool(dev, vaddr, size))		return; 	if (dma_set_encrypted(dev, vaddr, size))		return;	__dma_direct_free_pages(dev, page, size);} #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \    defined(CONFIG_SWIOTLB)void dma_direct_sync_sg_for_device(struct device *dev,		struct scatterlist *sgl, int nents, enum dma_data_direction dir){	struct scatterlist *sg;	int i; 	for_each_sg(sgl, sg, nents, i) {		phys_addr_t paddr = dma_to_phys(dev, sg_dma_address(sg)); 		swiotlb_sync_single_for_device(dev, paddr, sg->length, dir); 		if (!dev_is_dma_coherent(dev))			arch_sync_dma_for_device(paddr, sg->length,					dir);	}}#endif #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \    defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \    defined(CONFIG_SWIOTLB)void dma_direct_sync_sg_for_cpu(struct device *dev,		struct scatterlist *sgl, int nents, enum dma_data_direction dir){	struct scatterlist *sg;	int i; 	for_each_sg(sgl, sg, nents, i) {		phys_addr_t paddr = dma_to_phys(dev, sg_dma_address(sg)); 		if (!dev_is_dma_coherent(dev))			arch_sync_dma_for_cpu(paddr, sg->length, dir); 		swiotlb_sync_single_for_cpu(dev, paddr, sg->length, dir);	} 	if (!dev_is_dma_coherent(dev))		arch_sync_dma_for_cpu_all();} /* * Unmaps segments, except for ones marked as pci_p2pdma which do not * require any further action as they contain a bus address. */void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,		int nents, enum dma_data_direction dir, unsigned long attrs){	struct scatterlist *sg;	int i; 	for_each_sg(sgl,  sg, nents, i) {		if (sg_dma_is_bus_address(sg))			sg_dma_unmark_bus_address(sg);		else			dma_direct_unmap_phys(dev, sg->dma_address,					      sg_dma_len(sg), dir, attrs);	}}#endif int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,		enum dma_data_direction dir, unsigned long attrs){	struct pci_p2pdma_map_state p2pdma_state = {};	struct scatterlist *sg;	int i, ret; 	for_each_sg(sgl, sg, nents, i) {		switch (pci_p2pdma_state(&p2pdma_state, dev, sg_page(sg))) {		case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE:			/*			 * Any P2P mapping that traverses the PCI host bridge			 * must be mapped with CPU physical address and not PCI			 * bus addresses.			 */			break;		case PCI_P2PDMA_MAP_NONE:			sg->dma_address = dma_direct_map_phys(dev, sg_phys(sg),					sg->length, dir, attrs);			if (sg->dma_address == DMA_MAPPING_ERROR) {				ret = -EIO;				goto out_unmap;			}			break;		case PCI_P2PDMA_MAP_BUS_ADDR:			sg->dma_address = pci_p2pdma_bus_addr_map(				p2pdma_state.mem, sg_phys(sg));			sg_dma_len(sg) = sg->length;			sg_dma_mark_bus_address(sg);			continue;		default:			ret = -EREMOTEIO;			goto out_unmap;		}		sg_dma_len(sg) = sg->length;	} 	return nents; out_unmap:	dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);	return ret;} int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt,		void *cpu_addr, dma_addr_t dma_addr, size_t size,		unsigned long attrs)

Lines 1–500 of 665.