diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig | 2 | ||||
| -rw-r--r-- | lib/Makefile | 2 | ||||
| -rw-r--r-- | lib/dma-direct.c | 156 | ||||
| -rw-r--r-- | lib/dma-noop.c | 68 | ||||
| -rw-r--r-- | lib/swiotlb.c | 205 |
5 files changed, 285 insertions, 148 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index 4dd5c11366f9..e96089499371 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -413,7 +413,7 @@ config SGL_ALLOC bool default n -config DMA_NOOP_OPS +config DMA_DIRECT_OPS bool depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT) default n diff --git a/lib/Makefile b/lib/Makefile index d11c48ec8ffd..749851abe85a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -28,7 +28,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o -lib-$(CONFIG_DMA_NOOP_OPS) += dma-noop.o +lib-$(CONFIG_DMA_DIRECT_OPS) += dma-direct.o lib-$(CONFIG_DMA_VIRT_OPS) += dma-virt.o lib-y += kobject.o klist.o diff --git a/lib/dma-direct.c b/lib/dma-direct.c new file mode 100644 index 000000000000..40b1f92f2214 --- /dev/null +++ b/lib/dma-direct.c @@ -0,0 +1,156 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DMA operations that map physical memory directly without using an IOMMU or + * flushing caches. + */ +#include <linux/export.h> +#include <linux/mm.h> +#include <linux/dma-direct.h> +#include <linux/scatterlist.h> +#include <linux/dma-contiguous.h> +#include <linux/pfn.h> + +#define DIRECT_MAPPING_ERROR 0 + +/* + * Most architectures use ZONE_DMA for the first 16 Megabytes, but + * some use it for entirely different regions: + */ +#ifndef ARCH_ZONE_DMA_BITS +#define ARCH_ZONE_DMA_BITS 24 +#endif + +static bool +check_addr(struct device *dev, dma_addr_t dma_addr, size_t size, + const char *caller) +{ + if (unlikely(dev && !dma_capable(dev, dma_addr, size))) { + if (*dev->dma_mask >= DMA_BIT_MASK(32)) { + dev_err(dev, + "%s: overflow %pad+%zu of device mask %llx\n", + caller, &dma_addr, size, *dev->dma_mask); + } + return false; + } + return true; +} + +static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) +{ + return phys_to_dma(dev, phys) + size - 1 <= dev->coherent_dma_mask; +} + +void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, + gfp_t gfp, unsigned long attrs) +{ + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + int page_order = get_order(size); + struct page *page = NULL; + + /* GFP_DMA32 and GFP_DMA are no ops without the corresponding zones: */ + if (dev->coherent_dma_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS)) + gfp |= GFP_DMA; + if (dev->coherent_dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA)) + gfp |= GFP_DMA32; + +again: + /* CMA can be used only in the context which permits sleeping */ + if (gfpflags_allow_blocking(gfp)) { + page = dma_alloc_from_contiguous(dev, count, page_order, gfp); + if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { + dma_release_from_contiguous(dev, page, count); + page = NULL; + } + } + if (!page) + page = alloc_pages_node(dev_to_node(dev), gfp, page_order); + + if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { + __free_pages(page, page_order); + page = NULL; + + if (dev->coherent_dma_mask < DMA_BIT_MASK(32) && + !(gfp & GFP_DMA)) { + gfp = (gfp & ~GFP_DMA32) | GFP_DMA; + goto again; + } + } + + if (!page) + return NULL; + + *dma_handle = phys_to_dma(dev, page_to_phys(page)); + memset(page_address(page), 0, size); + return page_address(page); +} + +void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, + dma_addr_t dma_addr, unsigned long attrs) +{ + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + + if (!dma_release_from_contiguous(dev, virt_to_page(cpu_addr), count)) + free_pages((unsigned long)cpu_addr, get_order(size)); +} + +static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, enum dma_data_direction dir, + unsigned long attrs) +{ + dma_addr_t dma_addr = phys_to_dma(dev, page_to_phys(page)) + offset; + + if (!check_addr(dev, dma_addr, size, __func__)) + return DIRECT_MAPPING_ERROR; + return dma_addr; +} + +static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, + int nents, enum dma_data_direction dir, unsigned long attrs) +{ + int i; + struct scatterlist *sg; + + for_each_sg(sgl, sg, nents, i) { + BUG_ON(!sg_page(sg)); + + sg_dma_address(sg) = phys_to_dma(dev, sg_phys(sg)); + if (!check_addr(dev, sg_dma_address(sg), sg->length, __func__)) + return 0; + sg_dma_len(sg) = sg->length; + } + + return nents; +} + +int dma_direct_supported(struct device *dev, u64 mask) +{ +#ifdef CONFIG_ZONE_DMA + if (mask < DMA_BIT_MASK(ARCH_ZONE_DMA_BITS)) + return 0; +#else + /* + * Because 32-bit DMA masks are so common we expect every architecture + * to be able to satisfy them - either by not supporting more physical + * memory, or by providing a ZONE_DMA32. If neither is the case, the + * architecture needs to use an IOMMU instead of the direct mapping. + */ + if (mask < DMA_BIT_MASK(32)) + return 0; +#endif + return 1; +} + +static int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr) +{ + return dma_addr == DIRECT_MAPPING_ERROR; +} + +const struct dma_map_ops dma_direct_ops = { + .alloc = dma_direct_alloc, + .free = dma_direct_free, + .map_page = dma_direct_map_page, + .map_sg = dma_direct_map_sg, + .dma_supported = dma_direct_supported, + .mapping_error = dma_direct_mapping_error, +}; +EXPORT_SYMBOL(dma_direct_ops); diff --git a/lib/dma-noop.c b/lib/dma-noop.c deleted file mode 100644 index a10185b0c2d4..000000000000 --- a/lib/dma-noop.c +++ /dev/null @@ -1,68 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * lib/dma-noop.c - * - * DMA operations that map to physical addresses without flushing memory. - */ -#include <linux/export.h> -#include <linux/mm.h> -#include <linux/dma-mapping.h> -#include <linux/scatterlist.h> -#include <linux/pfn.h> - -static void *dma_noop_alloc(struct device *dev, size_t size, - dma_addr_t *dma_handle, gfp_t gfp, - unsigned long attrs) -{ - void *ret; - - ret = (void *)__get_free_pages(gfp, get_order(size)); - if (ret) - *dma_handle = virt_to_phys(ret) - PFN_PHYS(dev->dma_pfn_offset); - - return ret; -} - -static void dma_noop_free(struct device *dev, size_t size, - void *cpu_addr, dma_addr_t dma_addr, - unsigned long attrs) -{ - free_pages((unsigned long)cpu_addr, get_order(size)); -} - -static dma_addr_t dma_noop_map_page(struct device *dev, struct page *page, - unsigned long offset, size_t size, - enum dma_data_direction dir, - unsigned long attrs) -{ - return page_to_phys(page) + offset - PFN_PHYS(dev->dma_pfn_offset); -} - -static int dma_noop_map_sg(struct device *dev, struct scatterlist *sgl, int nents, - enum dma_data_direction dir, - unsigned long attrs) -{ - int i; - struct scatterlist *sg; - - for_each_sg(sgl, sg, nents, i) { - dma_addr_t offset = PFN_PHYS(dev->dma_pfn_offset); - void *va; - - BUG_ON(!sg_page(sg)); - va = sg_virt(sg); - sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va) - offset; - sg_dma_len(sg) = sg->length; - } - - return nents; -} - -const struct dma_map_ops dma_noop_ops = { - .alloc = dma_noop_alloc, - .free = dma_noop_free, - .map_page = dma_noop_map_page, - .map_sg = dma_noop_map_sg, -}; - -EXPORT_SYMBOL(dma_noop_ops); diff --git a/lib/swiotlb.c b/lib/swiotlb.c index cea19aaf303c..c43ec2271469 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -18,7 +18,7 @@ */ #include <linux/cache.h> -#include <linux/dma-mapping.h> +#include <linux/dma-direct.h> #include <linux/mm.h> #include <linux/export.h> #include <linux/spinlock.h> @@ -417,7 +417,7 @@ cleanup2: return -ENOMEM; } -void __init swiotlb_free(void) +void __init swiotlb_exit(void) { if (!io_tlb_orig_addr) return; @@ -586,7 +586,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, not_found: spin_unlock_irqrestore(&io_tlb_lock, flags); - if (printk_ratelimit()) + if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size); return SWIOTLB_MAP_ERROR; found: @@ -605,7 +605,6 @@ found: return tlb_addr; } -EXPORT_SYMBOL_GPL(swiotlb_tbl_map_single); /* * Allocates bounce buffer and returns its kernel virtual address. @@ -675,7 +674,6 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, } spin_unlock_irqrestore(&io_tlb_lock, flags); } -EXPORT_SYMBOL_GPL(swiotlb_tbl_unmap_single); void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, size_t size, enum dma_data_direction dir, @@ -707,92 +705,107 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, BUG(); } } -EXPORT_SYMBOL_GPL(swiotlb_tbl_sync_single); + +static inline bool dma_coherent_ok(struct device *dev, dma_addr_t addr, + size_t size) +{ + u64 mask = DMA_BIT_MASK(32); + + if (dev && dev->coherent_dma_mask) + mask = dev->coherent_dma_mask; + return addr + size - 1 <= mask; +} + +static void * +swiotlb_alloc_buffer(struct device *dev, size_t size, dma_addr_t *dma_handle, + unsigned long attrs) +{ + phys_addr_t phys_addr; + + if (swiotlb_force == SWIOTLB_NO_FORCE) + goto out_warn; + + phys_addr = swiotlb_tbl_map_single(dev, + swiotlb_phys_to_dma(dev, io_tlb_start), + 0, size, DMA_FROM_DEVICE, 0); + if (phys_addr == SWIOTLB_MAP_ERROR) + goto out_warn; + + *dma_handle = swiotlb_phys_to_dma(dev, phys_addr); + if (dma_coherent_ok(dev, *dma_handle, size)) + goto out_unmap; + + memset(phys_to_virt(phys_addr), 0, size); + return phys_to_virt(phys_addr); + +out_unmap: + dev_warn(dev, "hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n", + (unsigned long long)(dev ? dev->coherent_dma_mask : 0), + (unsigned long long)*dma_handle); + + /* + * DMA_TO_DEVICE to avoid memcpy in unmap_single. + * DMA_ATTR_SKIP_CPU_SYNC is optional. + */ + swiotlb_tbl_unmap_single(dev, phys_addr, size, DMA_TO_DEVICE, + DMA_ATTR_SKIP_CPU_SYNC); +out_warn: + if ((attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) { + dev_warn(dev, + "swiotlb: coherent allocation failed, size=%zu\n", + size); + dump_stack(); + } + return NULL; +} void * swiotlb_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags) { - dma_addr_t dev_addr; - void *ret; int order = get_order(size); - u64 dma_mask = DMA_BIT_MASK(32); - - if (hwdev && hwdev->coherent_dma_mask) - dma_mask = hwdev->coherent_dma_mask; + unsigned long attrs = (flags & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0; + void *ret; ret = (void *)__get_free_pages(flags, order); if (ret) { - dev_addr = swiotlb_virt_to_bus(hwdev, ret); - if (dev_addr + size - 1 > dma_mask) { - /* - * The allocated memory isn't reachable by the device. - */ - free_pages((unsigned long) ret, order); - ret = NULL; + *dma_handle = swiotlb_virt_to_bus(hwdev, ret); + if (dma_coherent_ok(hwdev, *dma_handle, size)) { + memset(ret, 0, size); + return ret; } + free_pages((unsigned long)ret, order); } - if (!ret) { - /* - * We are either out of memory or the device can't DMA to - * GFP_DMA memory; fall back on map_single(), which - * will grab memory from the lowest available address range. - */ - phys_addr_t paddr = map_single(hwdev, 0, size, - DMA_FROM_DEVICE, 0); - if (paddr == SWIOTLB_MAP_ERROR) - goto err_warn; - ret = phys_to_virt(paddr); - dev_addr = swiotlb_phys_to_dma(hwdev, paddr); - - /* Confirm address can be DMA'd by device */ - if (dev_addr + size - 1 > dma_mask) { - printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n", - (unsigned long long)dma_mask, - (unsigned long long)dev_addr); - - /* - * DMA_TO_DEVICE to avoid memcpy in unmap_single. - * The DMA_ATTR_SKIP_CPU_SYNC is optional. - */ - swiotlb_tbl_unmap_single(hwdev, paddr, - size, DMA_TO_DEVICE, - DMA_ATTR_SKIP_CPU_SYNC); - goto err_warn; - } - } + return swiotlb_alloc_buffer(hwdev, size, dma_handle, attrs); +} +EXPORT_SYMBOL(swiotlb_alloc_coherent); - *dma_handle = dev_addr; - memset(ret, 0, size); +static bool swiotlb_free_buffer(struct device *dev, size_t size, + dma_addr_t dma_addr) +{ + phys_addr_t phys_addr = dma_to_phys(dev, dma_addr); - return ret; + WARN_ON_ONCE(irqs_disabled()); -err_warn: - pr_warn("swiotlb: coherent allocation failed for device %s size=%zu\n", - dev_name(hwdev), size); - dump_stack(); + if (!is_swiotlb_buffer(phys_addr)) + return false; - return NULL; + /* + * DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single. + * DMA_ATTR_SKIP_CPU_SYNC is optional. + */ + swiotlb_tbl_unmap_single(dev, phys_addr, size, DMA_TO_DEVICE, + DMA_ATTR_SKIP_CPU_SYNC); + return true; } -EXPORT_SYMBOL(swiotlb_alloc_coherent); void swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dev_addr) { - phys_addr_t paddr = dma_to_phys(hwdev, dev_addr); - - WARN_ON(irqs_disabled()); - if (!is_swiotlb_buffer(paddr)) + if (!swiotlb_free_buffer(hwdev, size, dev_addr)) free_pages((unsigned long)vaddr, get_order(size)); - else - /* - * DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single. - * DMA_ATTR_SKIP_CPU_SYNC is optional. - */ - swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE, - DMA_ATTR_SKIP_CPU_SYNC); } EXPORT_SYMBOL(swiotlb_free_coherent); @@ -868,7 +881,6 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, return swiotlb_phys_to_dma(dev, io_tlb_overflow_buffer); } -EXPORT_SYMBOL_GPL(swiotlb_map_page); /* * Unmap a single streaming mode DMA translation. The dma_addr and size must @@ -909,7 +921,6 @@ void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, { unmap_single(hwdev, dev_addr, size, dir, attrs); } -EXPORT_SYMBOL_GPL(swiotlb_unmap_page); /* * Make physical memory consistent for a single streaming mode DMA translation @@ -947,7 +958,6 @@ swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, { swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU); } -EXPORT_SYMBOL(swiotlb_sync_single_for_cpu); void swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, @@ -955,7 +965,6 @@ swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, { swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE); } -EXPORT_SYMBOL(swiotlb_sync_single_for_device); /* * Map a set of buffers described by scatterlist in streaming mode for DMA. @@ -1007,7 +1016,6 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems, } return nelems; } -EXPORT_SYMBOL(swiotlb_map_sg_attrs); /* * Unmap a set of streaming mode DMA translations. Again, cpu read rules @@ -1027,7 +1035,6 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir, attrs); } -EXPORT_SYMBOL(swiotlb_unmap_sg_attrs); /* * Make physical memory consistent for a set of streaming mode DMA translations @@ -1055,7 +1062,6 @@ swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, { swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU); } -EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu); void swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, @@ -1063,14 +1069,12 @@ swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, { swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE); } -EXPORT_SYMBOL(swiotlb_sync_sg_for_device); int swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) { return (dma_addr == swiotlb_phys_to_dma(hwdev, io_tlb_overflow_buffer)); } -EXPORT_SYMBOL(swiotlb_dma_mapping_error); /* * Return whether the given device DMA address mask can be supported @@ -1083,4 +1087,49 @@ swiotlb_dma_supported(struct device *hwdev, u64 mask) { return swiotlb_phys_to_dma(hwdev, io_tlb_end - 1) <= mask; } -EXPORT_SYMBOL(swiotlb_dma_supported); + +#ifdef CONFIG_DMA_DIRECT_OPS +void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, + gfp_t gfp, unsigned long attrs) +{ + void *vaddr; + + /* temporary workaround: */ + if (gfp & __GFP_NOWARN) + attrs |= DMA_ATTR_NO_WARN; + + /* + * Don't print a warning when the first allocation attempt fails. + * swiotlb_alloc_coherent() will print a warning when the DMA memory + * allocation ultimately failed. + */ + gfp |= __GFP_NOWARN; + + vaddr = dma_direct_alloc(dev, size, dma_handle, gfp, attrs); + if (!vaddr) + vaddr = swiotlb_alloc_buffer(dev, size, dma_handle, attrs); + return vaddr; +} + +void swiotlb_free(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_addr, unsigned long attrs) +{ + if (!swiotlb_free_buffer(dev, size, dma_addr)) + dma_direct_free(dev, size, vaddr, dma_addr, attrs); +} + +const struct dma_map_ops swiotlb_dma_ops = { + .mapping_error = swiotlb_dma_mapping_error, + .alloc = swiotlb_alloc, + .free = swiotlb_free, + .sync_single_for_cpu = swiotlb_sync_single_for_cpu, + .sync_single_for_device = swiotlb_sync_single_for_device, + .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = swiotlb_sync_sg_for_device, + .map_sg = swiotlb_map_sg_attrs, + .unmap_sg = swiotlb_unmap_sg_attrs, + .map_page = swiotlb_map_page, + .unmap_page = swiotlb_unmap_page, + .dma_supported = swiotlb_dma_supported, +}; +#endif /* CONFIG_DMA_DIRECT_OPS */ |