diff options
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/direct.c | 240 | ||||
| -rw-r--r-- | kernel/dma/pool.c | 4 | ||||
| -rw-r--r-- | kernel/dma/swiotlb.c | 50 |
3 files changed, 190 insertions, 104 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 4c6c5e0635e3..50f48e9e4598 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -75,15 +75,45 @@ static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) 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, 1 << get_order(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, 1 << get_order(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 (IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL) && - swiotlb_free(dev, page, 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) { @@ -93,18 +123,11 @@ static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size, 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, dev->coherent_dma_mask, &phys_limit); - if (IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL) && - is_swiotlb_for_alloc(dev)) { - page = swiotlb_alloc(dev, size); - if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { - __dma_direct_free_pages(dev, page, size); - return NULL; - } - return page; - } - page = dma_alloc_contiguous(dev, size, gfp); if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { dma_free_contiguous(dev, page, size); @@ -133,6 +156,15 @@ again: 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) { @@ -140,6 +172,9 @@ static void *dma_direct_alloc_from_pool(struct device *dev, size_t size, u64 phys_mask; void *ret; + if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_DMA_COHERENT_POOL))) + return NULL; + gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask, &phys_mask); page = dma_alloc_from_pool(dev, size, &ret, gfp, dma_coherent_ok); @@ -149,64 +184,103 @@ static void *dma_direct_alloc_from_pool(struct device *dev, size_t size, 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); + 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; - int err; 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)) { - page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO); - if (!page) - return NULL; - /* remove any dirty cache lines on the kernel alias */ - if (!PageHighMem(page)) - arch_dma_prep_coherent(page, size); - *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); - /* return the page pointer as the opaque cookie */ - return page; - } + !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) + return dma_direct_alloc_no_mapping(dev, size, dma_handle, gfp); - if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && - !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && - !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && - !dev_is_dma_coherent(dev) && - !is_swiotlb_for_alloc(dev)) - return arch_dma_alloc(dev, size, dma_handle, gfp, attrs); + if (!dev_is_dma_coherent(dev)) { + /* + * Fallback to the arch handler if it exists. This should + * eventually go away. + */ + if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && + !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && + !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && + !is_swiotlb_for_alloc(dev)) + return arch_dma_alloc(dev, size, dma_handle, gfp, + attrs); - if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && - !dev_is_dma_coherent(dev)) - return dma_alloc_from_global_coherent(dev, size, dma_handle); + /* + * 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 remap if the architecture is asking for it. But + * given that remapping memory is a blocking operation we'll + * instead have to dip into the atomic pools. + */ + remap = IS_ENABLED(CONFIG_DMA_DIRECT_REMAP); + if (remap) { + if (dma_direct_use_pool(dev, gfp)) + return dma_direct_alloc_from_pool(dev, size, + dma_handle, gfp); + } else { + if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED)) + return NULL; + set_uncached = true; + } + } /* - * Remapping or decrypting memory may block. If either is required and - * we can't block, allocate the memory from the atomic pools. - * If restricted DMA (i.e., is_swiotlb_for_alloc) is required, one must - * set up another device coherent pool by shared-dma-pool and use - * dma_alloc_from_dev_coherent instead. + * Decrypting memory may block, so allocate the memory from the atomic + * pools if we can't block. */ - if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && - !gfpflags_allow_blocking(gfp) && - (force_dma_unencrypted(dev) || - (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && - !dev_is_dma_coherent(dev))) && - !is_swiotlb_for_alloc(dev)) + if (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); if (!page) return NULL; + if (PageHighMem(page)) { + /* + * Depending on the cma= arguments and per-arch setup, + * dma_alloc_contiguous could return highmem pages. + * Without remapping there is no way to return them here, so + * log an error and fail. + */ + if (!IS_ENABLED(CONFIG_DMA_REMAP)) { + dev_info(dev, "Rejecting highmem page from CMA.\n"); + goto out_free_pages; + } + remap = true; + set_uncached = false; + } - if ((IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && - !dev_is_dma_coherent(dev)) || - (IS_ENABLED(CONFIG_DMA_REMAP) && PageHighMem(page))) { + if (remap) { /* remove any dirty cache lines on the kernel alias */ arch_dma_prep_coherent(page, size); @@ -216,56 +290,27 @@ void *dma_direct_alloc(struct device *dev, size_t size, __builtin_return_address(0)); if (!ret) goto out_free_pages; - if (force_dma_unencrypted(dev)) { - err = set_memory_decrypted((unsigned long)ret, - 1 << get_order(size)); - if (err) - goto out_free_pages; - } - memset(ret, 0, size); - goto done; - } - - if (PageHighMem(page)) { - /* - * Depending on the cma= arguments and per-arch setup - * dma_alloc_contiguous could return highmem pages. - * Without remapping there is no way to return them here, - * so log an error and fail. - */ - dev_info(dev, "Rejecting highmem page from CMA.\n"); - goto out_free_pages; - } - - ret = page_address(page); - if (force_dma_unencrypted(dev)) { - err = set_memory_decrypted((unsigned long)ret, - 1 << get_order(size)); - if (err) + } else { + ret = page_address(page); + if (dma_set_decrypted(dev, ret, size)) goto out_free_pages; } memset(ret, 0, size); - if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && - !dev_is_dma_coherent(dev)) { + if (set_uncached) { arch_dma_prep_coherent(page, size); ret = arch_dma_set_uncached(ret, size); if (IS_ERR(ret)) goto out_encrypt_pages; } -done: + *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); return ret; out_encrypt_pages: - if (force_dma_unencrypted(dev)) { - err = set_memory_encrypted((unsigned long)page_address(page), - 1 << get_order(size)); - /* If memory cannot be re-encrypted, it must be leaked */ - if (err) - return NULL; - } + if (dma_set_encrypted(dev, page_address(page), size)) + return NULL; out_free_pages: __dma_direct_free_pages(dev, page, size); return NULL; @@ -304,13 +349,14 @@ void dma_direct_free(struct device *dev, size_t size, dma_free_from_pool(dev, cpu_addr, PAGE_ALIGN(size))) return; - if (force_dma_unencrypted(dev)) - set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order); - - if (IS_ENABLED(CONFIG_DMA_REMAP) && is_vmalloc_addr(cpu_addr)) + if (IS_ENABLED(CONFIG_DMA_REMAP) && 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); + } else { + if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_CLEAR_UNCACHED)) + arch_dma_clear_uncached(cpu_addr, size); + if (dma_set_encrypted(dev, cpu_addr, 1 << page_order)) + return; + } __dma_direct_free_pages(dev, dma_direct_to_page(dev, dma_addr), size); } @@ -321,9 +367,7 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, struct page *page; void *ret; - if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && - force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) && - !is_swiotlb_for_alloc(dev)) + 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); @@ -341,11 +385,8 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, } ret = page_address(page); - if (force_dma_unencrypted(dev)) { - if (set_memory_decrypted((unsigned long)ret, - 1 << get_order(size))) - goto out_free_pages; - } + if (dma_set_decrypted(dev, ret, size)) + goto out_free_pages; memset(ret, 0, size); *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); return page; @@ -366,9 +407,8 @@ void dma_direct_free_pages(struct device *dev, size_t size, dma_free_from_pool(dev, vaddr, size)) return; - if (force_dma_unencrypted(dev)) - set_memory_encrypted((unsigned long)vaddr, 1 << page_order); - + if (dma_set_encrypted(dev, vaddr, 1 << page_order)) + return; __dma_direct_free_pages(dev, page, size); } diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c index 5f84e6cdb78e..4d40dcce7604 100644 --- a/kernel/dma/pool.c +++ b/kernel/dma/pool.c @@ -203,7 +203,7 @@ static int __init dma_atomic_pool_init(void) GFP_KERNEL); if (!atomic_pool_kernel) ret = -ENOMEM; - if (IS_ENABLED(CONFIG_ZONE_DMA)) { + if (has_managed_dma()) { atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size, GFP_KERNEL | GFP_DMA); if (!atomic_pool_dma) @@ -226,7 +226,7 @@ static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp) if (prev == NULL) { if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32)) return atomic_pool_dma32; - if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA)) + if (atomic_pool_dma && (gfp & GFP_DMA)) return atomic_pool_dma; return atomic_pool_kernel; } diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 8e840fbbed7c..f1e7ea160b43 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -50,6 +50,7 @@ #include <asm/io.h> #include <asm/dma.h> +#include <linux/io.h> #include <linux/init.h> #include <linux/memblock.h> #include <linux/iommu-helper.h> @@ -72,6 +73,8 @@ enum swiotlb_force swiotlb_force; struct io_tlb_mem io_tlb_default_mem; +phys_addr_t swiotlb_unencrypted_base; + /* * Max segment that we can provide which (if pages are contingous) will * not be bounced (unless SWIOTLB_FORCE is set). @@ -156,6 +159,34 @@ static inline unsigned long nr_slots(u64 val) } /* + * Remap swioltb memory in the unencrypted physical address space + * when swiotlb_unencrypted_base is set. (e.g. for Hyper-V AMD SEV-SNP + * Isolation VMs). + */ +#ifdef CONFIG_HAS_IOMEM +static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes) +{ + void *vaddr = NULL; + + if (swiotlb_unencrypted_base) { + phys_addr_t paddr = mem->start + swiotlb_unencrypted_base; + + vaddr = memremap(paddr, bytes, MEMREMAP_WB); + if (!vaddr) + pr_err("Failed to map the unencrypted memory %pa size %lx.\n", + &paddr, bytes); + } + + return vaddr; +} +#else +static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes) +{ + return NULL; +} +#endif + +/* * Early SWIOTLB allocation may be too early to allow an architecture to * perform the desired operations. This function allows the architecture to * call SWIOTLB when the operations are possible. It needs to be called @@ -172,7 +203,12 @@ void __init swiotlb_update_mem_attributes(void) vaddr = phys_to_virt(mem->start); bytes = PAGE_ALIGN(mem->nslabs << IO_TLB_SHIFT); set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT); - memset(vaddr, 0, bytes); + + mem->vaddr = swiotlb_mem_remap(mem, bytes); + if (!mem->vaddr) + mem->vaddr = vaddr; + + memset(mem->vaddr, 0, bytes); } static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, @@ -196,7 +232,17 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, mem->slots[i].orig_addr = INVALID_PHYS_ADDR; mem->slots[i].alloc_size = 0; } + + /* + * If swiotlb_unencrypted_base is set, the bounce buffer memory will + * be remapped and cleared in swiotlb_update_mem_attributes. + */ + if (swiotlb_unencrypted_base) + return; + memset(vaddr, 0, bytes); + mem->vaddr = vaddr; + return; } int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) @@ -371,7 +417,7 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size phys_addr_t orig_addr = mem->slots[index].orig_addr; size_t alloc_size = mem->slots[index].alloc_size; unsigned long pfn = PFN_DOWN(orig_addr); - unsigned char *vaddr = phys_to_virt(tlb_addr); + unsigned char *vaddr = mem->vaddr + tlb_addr - mem->start; unsigned int tlb_offset, orig_addr_offset; if (orig_addr == INVALID_PHYS_ADDR) |