// SPDX-License-Identifier: GPL-2.0-only /* * Dynamic DMA mapping support. * * This implementation is a fallback for platforms that do not support * I/O TLBs (aka DMA address translation hardware). * Copyright (C) 2000 Asit Mallick * Copyright (C) 2000 Goutham Rao * Copyright (C) 2000, 2003 Hewlett-Packard Co * David Mosberger-Tang * * 03/05/07 davidm Switch from PCI-DMA to generic device DMA API. * 00/12/13 davidm Rename to swiotlb.c and add mark_clean() to avoid * unnecessary i-cache flushing. * 04/07/.. ak Better overflow handling. Assorted fixes. * 05/09/10 linville Add support for syncing ranges, support syncing for * DMA_BIDIRECTIONAL mappings, miscellaneous cleanup. * 08/12/11 beckyb Add highmem support */ #define pr_fmt(fmt) "software IO TLB: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_DMA_RESTRICTED_POOL #include #include #include #include #endif #define CREATE_TRACE_POINTS #include #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT)) /* * Minimum IO TLB size to bother booting with. Systems with mainly * 64bit capable cards will only lightly use the swiotlb. If we can't * allocate a contiguous 1MB, we're probably in trouble anyway. */ #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT) #define INVALID_PHYS_ADDR (~(phys_addr_t)0) /** * struct io_tlb_slot - IO TLB slot descriptor * @orig_addr: The original address corresponding to a mapped entry. * @alloc_size: Size of the allocated buffer. * @list: The free list describing the number of free entries available * from each index. * @pad_slots: Number of preceding padding slots. Valid only in the first * allocated non-padding slot. */ struct io_tlb_slot { phys_addr_t orig_addr; size_t alloc_size; unsigned short list; unsigned short pad_slots; }; static bool swiotlb_force_bounce; static bool swiotlb_force_disable; #ifdef CONFIG_SWIOTLB_DYNAMIC static void swiotlb_dyn_alloc(struct work_struct *work); static struct io_tlb_mem io_tlb_default_mem = { .lock = __SPIN_LOCK_UNLOCKED(io_tlb_default_mem.lock), .pools = LIST_HEAD_INIT(io_tlb_default_mem.pools), .dyn_alloc = __WORK_INITIALIZER(io_tlb_default_mem.dyn_alloc, swiotlb_dyn_alloc), }; #else /* !CONFIG_SWIOTLB_DYNAMIC */ static struct io_tlb_mem io_tlb_default_mem; #endif /* CONFIG_SWIOTLB_DYNAMIC */ static unsigned long default_nslabs = IO_TLB_DEFAULT_SIZE >> IO_TLB_SHIFT; static unsigned long default_nareas; /** * struct io_tlb_area - IO TLB memory area descriptor * * This is a single area with a single lock. * * @used: The number of used IO TLB block. * @index: The slot index to start searching in this area for next round. * @lock: The lock to protect the above data structures in the map and * unmap calls. */ struct io_tlb_area { unsigned long used; unsigned int index; spinlock_t lock; }; /* * Round up number of slabs to the next power of 2. The last area is going * be smaller than the rest if default_nslabs is not power of two. * The number of slot in an area should be a multiple of IO_TLB_SEGSIZE, * otherwise a segment may span two or more areas. It conflicts with free * contiguous slots tracking: free slots are treated contiguous no matter * whether they cross an area boundary. * * Return true if default_nslabs is rounded up. */ static bool round_up_default_nslabs(void) { if (!default_nareas) return false; if (default_nslabs < IO_TLB_SEGSIZE * default_nareas) default_nslabs = IO_TLB_SEGSIZE * default_nareas; else if (is_power_of_2(default_nslabs)) return false; default_nslabs = roundup_pow_of_two(default_nslabs); return true; } /** * swiotlb_adjust_nareas() - adjust the number of areas and slots * @nareas: Desired number of areas. Zero is treated as 1. * * Adjust the default number of areas in a memory pool. * The default size of the memory pool may also change to meet minimum area * size requirements. */ static void swiotlb_adjust_nareas(unsigned int nareas) { if (!nareas) nareas = 1; else if (!is_power_of_2(nareas)) nareas = roundup_pow_of_two(nareas); default_nareas = nareas; pr_info("area num %d.\n", nareas); if (round_up_default_nslabs()) pr_info("SWIOTLB bounce buffer size roundup to %luMB", (default_nslabs << IO_TLB_SHIFT) >> 20); } /** * limit_nareas() - get the maximum number of areas for a given memory pool size * @nareas: Desired number of areas. * @nslots: Total number of slots in the memory pool. * * Limit the number of areas to the maximum possible number of areas in * a memory pool of the given size. * * Return: Maximum possible number of areas. */ static unsigned int limit_nareas(unsigned int nareas, unsigned long nslots) { if (nslots < nareas * IO_TLB_SEGSIZE) return nslots / IO_TLB_SEGSIZE; return nareas; } static int __init setup_io_tlb_npages(char *str) { if (isdigit(*str)) { /* avoid tail segment of size < IO_TLB_SEGSIZE */ default_nslabs = ALIGN(simple_strtoul(str, &str, 0), IO_TLB_SEGSIZE); } if (*str == ',') ++str; if (isdigit(*str)) swiotlb_adjust_nareas(simple_strtoul(str, &str, 0)); if (*str == ',') ++str; if (!strcmp(str, "force")) swiotlb_force_bounce = true; else if (!strcmp(str, "noforce")) swiotlb_force_disable = true; return 0; } early_param("swiotlb", setup_io_tlb_npages); unsigned long swiotlb_size_or_default(void) { return default_nslabs << IO_TLB_SHIFT; } void __init swiotlb_adjust_size(unsigned long size) { /* * If swiotlb parameter has not been specified, give a chance to * architectures such as those supporting memory encryption to * adjust/expand SWIOTLB size for their use. */ if (default_nslabs != IO_TLB_DEFAULT_SIZE >> IO_TLB_SHIFT) return; size = ALIGN(size, IO_TLB_SIZE); default_nslabs = ALIGN(size >> IO_TLB_SHIFT, IO_TLB_SEGSIZE); if (round_up_default_nslabs()) size = default_nslabs << IO_TLB_SHIFT; pr_info("SWIOTLB bounce buffer size adjusted to %luMB", size >> 20); } void swiotlb_print_info(void) { struct io_tlb_pool *mem = &io_tlb_default_mem.defpool; if (!mem->nslabs) { pr_warn("No low mem\n"); return; } pr_info("mapped [mem %pa-%pa] (%luMB)\n", &mem->start, &mem->end, (mem->nslabs << IO_TLB_SHIFT) >> 20); } static inline unsigned long io_tlb_offset(unsigned long val) { return val & (IO_TLB_SEGSIZE - 1); } static inline unsigned long nr_slots(u64 val) { return DIV_ROUND_UP(val, IO_TLB_SIZE); } /* * 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 * before the SWIOTLB memory is used. */ void __init swiotlb_update_mem_attributes(void) { struct io_tlb_pool *mem = &io_tlb_default_mem.defpool; unsigned long bytes; if (!mem->nslabs || mem->late_alloc) return; bytes = PAGE_ALIGN(mem->nslabs << IO_TLB_SHIFT); set_memory_decrypted((unsigned long)mem->vaddr, bytes >> PAGE_SHIFT); } static void swiotlb_init_io_tlb_pool(struct io_tlb_pool *mem, phys_addr_t start, unsigned long nslabs, bool late_alloc, unsigned int nareas) { void *vaddr = phys_to_virt(start); unsigned long bytes = nslabs << IO_TLB_SHIFT, i; mem->nslabs = nslabs; mem->start = start; mem->end = mem->start + bytes; mem->late_alloc = late_alloc; mem->nareas = nareas; mem->area_nslabs = nslabs / mem->nareas; for (i = 0; i < mem->nareas; i++) { spin_lock_init(&mem->areas[i].lock); mem->areas[i].index = 0; mem->areas[i].used = 0; } for (i = 0; i < mem->nslabs; i++) { mem->slots[i].list = min(IO_TLB_SEGSIZE - io_tlb_offset(i), mem->nslabs - i); mem->slots[i].orig_addr = INVALID_PHYS_ADDR; mem->slots[i].alloc_size = 0; mem->slots[i].pad_slots = 0; } memset(vaddr, 0, bytes); mem->vaddr = vaddr; return; } /** * add_mem_pool() - add a memory pool to the allocator * @mem: Software IO TLB allocator. * @pool: Memory pool to be added. */ static void add_mem_pool(struct io_tlb_mem *mem, struct io_tlb_pool *pool) { #ifdef CONFIG_SWIOTLB_DYNAMIC spin_lock(&mem->lock); list_add_rcu(&pool->node, &mem->pools); mem->nslabs += pool->nslabs; spin_unlock(&mem->lock); #else mem->nslabs = pool->nslabs; #endif } static void __init *swiotlb_memblock_alloc(unsigned long nslabs, unsigned int flags, int (*remap)(void *tlb, unsigned long nslabs)) { size_t bytes = PAGE_ALIGN(nslabs << IO_TLB_SHIFT); void *tlb; /* * By default allocate the bounce buffer memory from low memory, but * allow to pick a location everywhere for hypervisors with guest * memory encryption. */ if (flags & SWIOTLB_ANY) tlb = memblock_alloc(bytes, PAGE_SIZE); else tlb = memblock_alloc_low(bytes, PAGE_SIZE); if (!tlb) { pr_warn("%s: Failed to allocate %zu bytes tlb structure\n", __func__, bytes); return NULL; } if (remap && remap(tlb, nslabs) < 0) { memblock_free(tlb, PAGE_ALIGN(bytes)); pr_warn("%s: Failed to remap %zu bytes\n", __func__, bytes); return NULL; } return tlb; } /* * Statically reserve bounce buffer space and initialize bounce buffer data * structures for the software IO TLB used to implement the DMA API. */ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags, int (*remap)(void *tlb, unsigned long nslabs)) { struct io_tlb_pool *mem = &io_tlb_default_mem.defpool; unsigned long nslabs; unsigned int nareas; size_t alloc_size; void *tlb; if (!addressing_limit && !swiotlb_force_bounce) return; if (swiotlb_force_disable) return; io_tlb_default_mem.force_bounce = swiotlb_force_bounce || (flags & SWIOTLB_FORCE); #ifdef CONFIG_SWIOTLB_DYNAMIC if (!remap) io_tlb_default_mem.can_grow = true; if (flags & SWIOTLB_ANY) io_tlb_default_mem.phys_limit = virt_to_phys(high_memory - 1); else io_tlb_default_mem.phys_limit = ARCH_LOW_ADDRESS_LIMIT; #endif if (!default_nareas) swiotlb_adjust_nareas(num_possible_cpus()); nslabs = default_nslabs; nareas = limit_nareas(default_nareas, nslabs); while ((tlb = swiotlb_memblock_alloc(nslabs, flags, remap)) == NULL) { if (nslabs <= IO_TLB_MIN_SLABS) return; nslabs = ALIGN(nslabs >> 1, IO_TLB_SEGSIZE); nareas = limit_nareas(nareas, nslabs); } if (default_nslabs != nslabs) { pr_info("SWIOTLB bounce buffer size adjusted %lu -> %lu slabs", default_nslabs, nslabs); default_nslabs = nslabs; } alloc_size = PAGE_ALIGN(array_size(sizeof(*mem->slots), nslabs)); mem->slots = memblock_alloc(alloc_size, PAGE_SIZE); if (!mem->slots) { pr_warn("%s: Failed to allocate %zu bytes align=0x%lx\n", __func__, alloc_size, PAGE_SIZE); return; } mem->areas = memblock_alloc(array_size(sizeof(struct io_tlb_area), nareas), SMP_CACHE_BYTES); if (!mem->areas) { pr_warn("%s: Failed to allocate mem->areas.\n", __func__); return; } swiotlb_init_io_tlb_pool(mem, __pa(tlb), nslabs, false, nareas); add_mem_pool(&io_tlb_default_mem, mem); if (flags & SWIOTLB_VERBOSE) swiotlb_print_info(); } void __init swiotlb_init(bool addressing_limit, unsigned int flags) { swiotlb_init_remap(addressing_limit, flags, NULL); } /* * Systems with larger DMA zones (those that don't support ISA) can * initialize the swiotlb later using the slab allocator if needed. * This should be just like above, but with some error catching. */ int swiotlb_init_late(size_t size, gfp_t gfp_mask, int (*remap)(void *tlb, unsigned long nslabs)) { struct io_tlb_pool *mem = &io_tlb_default_mem.defpool; unsigned long nslabs = ALIGN(size >> IO_TLB_SHIFT, IO_TLB_SEGSIZE); unsigned int nareas; unsigned char *vstart = NULL; unsigned int order, area_order; bool retried = false; int rc = 0; if (io_tlb_default_mem.nslabs) return 0; if (swiotlb_force_disable) return 0; io_tlb_default_mem.force_bounce = swiotlb_force_bounce; #ifdef CONFIG_SWIOTLB_DYNAMIC if (!remap) io_tlb_default_mem.can_grow = true; if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp_mask & __GFP_DMA)) io_tlb_default_mem.phys_limit = DMA_BIT_MASK(zone_dma_bits); else if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp_mask & __GFP_DMA32)) io_tlb_default_mem.phys_limit = DMA_BIT_MASK(32); else io_tlb_default_mem.phys_limit = virt_to_phys(high_memory - 1); #endif if (!default_nareas) swiotlb_adjust_nareas(num_possible_cpus()); retry: order = get_order(nslabs << IO_TLB_SHIFT); nslabs = SLABS_PER_PAGE << order; while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) { vstart = (void *)__get_free_pages(gfp_mask | __GFP_NOWARN, order); if (vstart) break; order--; nslabs = SLABS_PER_PAGE << order; retried = true; } if (!vstart) return -ENOMEM; if (remap) rc = remap(vstart, nslabs); if (rc) { free_pages((unsigned long)vstart, order); nslabs = ALIGN(nslabs >> 1, IO_TLB_SEGSIZE); if (nslabs < IO_TLB_MIN_SLABS) return rc; retried = true; goto retry; } if (retried) { pr_warn("only able to allocate %ld MB\n", (PAGE_SIZE << order) >> 20); } nareas = limit_nareas(default_nareas, nslabs); area_order = get_order(array_size(sizeof(*mem->areas), nareas)); mem->areas = (struct io_tlb_area *) __get_free_pages(GFP_KERNEL | __GFP_ZERO, area_order); if (!mem->areas) goto error_area; mem->slots = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(array_size(sizeof(*mem->slots), nslabs))); if (!mem->slots) goto error_slots; set_memory_decrypted((unsigned long)vstart, (nslabs << IO_TLB_SHIFT) >> PAGE_SHIFT); swiotlb_init_io_tlb_pool(mem, virt_to_phys(vstart), nslabs, true, nareas); add_mem_pool(&io_tlb_default_mem, mem); swiotlb_print_info(); return 0; error_slots: free_pages((unsigned long)mem->areas, area_order); error_area: free_pages((unsigned long)vstart, order); return -ENOMEM; } void __init swiotlb_exit(void) { struct io_tlb_pool *mem = &io_tlb_default_mem.defpool; unsigned long tbl_vaddr; size_t tbl_size, slots_size; unsigned int area_order; if (swiotlb_force_bounce) return; if (!mem->nslabs) return; pr_info("tearing down default memory pool\n"); tbl_vaddr = (unsigned long)phys_to_virt(mem->start); tbl_size = PAGE_ALIGN(mem->end - mem->start); slots_size = PAGE_ALIGN(array_size(sizeof(*mem->slots), mem->nslabs)); set_memory_encrypted(tbl_vaddr, tbl_size >> PAGE_SHIFT); if (mem->late_alloc) { area_order = get_order(array_size(sizeof(*mem->areas), mem->nareas)); free_pages((unsigned long)mem->areas, area_order); free_pages(tbl_vaddr, get_order(tbl_size)); free_pages((unsigned long)mem->slots, get_order(slots_size)); } else { memblock_free_late(__pa(mem->areas), array_size(sizeof(*mem->areas), mem->nareas)); memblock_free_late(mem->start, tbl_size); memblock_free_late(__pa(mem->slots), slots_size); } memset(mem, 0, sizeof(*mem)); } #ifdef CONFIG_SWIOTLB_DYNAMIC /** * alloc_dma_pages() - allocate pages to be used for DMA * @gfp: GFP flags for the allocation. * @bytes: Size of the buffer. * @phys_limit: Maximum allowed physical address of the buffer. * * Allocate pages from the buddy allocator. If successful, make the allocated * pages decrypted that they can be used for DMA. * * Return: Decrypted pages, %NULL on allocation failure, or ERR_PTR(-EAGAIN) * if the allocated physical address was above @phys_limit. */ static struct page *alloc_dma_pages(gfp_t gfp, size_t bytes, u64 phys_limit) { unsigned int order = get_order(bytes); struct page *page; phys_addr_t paddr; void *vaddr; page = alloc_pages(gfp, order); if (!page) return NULL; paddr = page_to_phys(page); if (paddr + bytes - 1 > phys_limit) { __free_pages(page, order); return ERR_PTR(-EAGAIN); } vaddr = phys_to_virt(paddr); if (set_memory_decrypted((unsigned long)vaddr, PFN_UP(bytes))) goto error; return page; error: /* Intentional leak if pages cannot be encrypted again. */ if (!set_memory_encrypted((unsigned long)vaddr, PFN_UP(bytes))) __free_pages(page, order); return NULL; } /** * swiotlb_alloc_tlb() - allocate a dynamic IO TLB buffer * @dev: Device for which a memory pool is allocated. * @bytes: Size of the buffer. * @phys_limit: Maximum allowed physical address of the buffer. * @gfp: GFP flags for the allocation. * * Return: Allocated pages, or %NULL on allocation failure. */ static struct page *swiotlb_alloc_tlb(struct device *dev, size_t bytes, u64 phys_limit, gfp_t gfp) { struct page *page; /* * Allocate from the atomic pools if memory is encrypted and * the allocation is atomic, because decrypting may block. */ if (!gfpflags_allow_blocking(gfp) && dev && force_dma_unencrypted(dev)) { void *vaddr; if (!IS_ENABLED(CONFIG_DMA_COHERENT_POOL)) return NULL; return dma_alloc_from_pool(dev, bytes, &vaddr, gfp, dma_coherent_ok); } gfp &= ~GFP_ZONEMASK; if (phys_limit <= DMA_BIT_MASK(zone_dma_bits)) gfp |= __GFP_DMA; else if (phys_limit <= DMA_BIT_MASK(32)) gfp |= __GFP_DMA32; while (IS_ERR(page = alloc_dma_pages(gfp, bytes, phys_limit))) { 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; } /** * swiotlb_free_tlb() - free a dynamically allocated IO TLB buffer * @vaddr: Virtual address of the buffer. * @bytes: Size of the buffer. */ static void swiotlb_free_tlb(void *vaddr, size_t bytes) { if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && dma_free_from_pool(NULL, vaddr, bytes)) return; /* Intentional leak if pages cannot be encrypted again. */ if (!set_memory_encrypted((unsigned long)vaddr, PFN_UP(bytes))) __free_pages(virt_to_page(vaddr), get_order(bytes)); } /** * swiotlb_alloc_pool() - allocate a new IO TLB memory pool * @dev: Device for which a memory pool is allocated. * @minslabs: Minimum number of slabs. * @nslabs: Desired (maximum) number of slabs. * @nareas: Number of areas. * @phys_limit: Maximum DMA buffer physical address. * @gfp: GFP flags for the allocations. * * Allocate and initialize a new IO TLB memory pool. The actual number of * slabs may be reduced if allocation of @nslabs fails. If even * @minslabs cannot be allocated, this function fails. * * Return: New memory pool, or %NULL on allocation failure. */ static struct io_tlb_pool *swiotlb_alloc_pool(struct device *dev, unsigned long minslabs, unsigned long nslabs, unsigned int nareas, u64 phys_limit, gfp_t gfp) { struct io_tlb_pool *pool; unsigned int slot_order; struct page *tlb; size_t pool_size; size_t tlb_size; if (nslabs > SLABS_PER_PAGE << MAX_PAGE_ORDER) { nslabs = SLABS_PER_PAGE << MAX_PAGE_ORDER; nareas = limit_nareas(nareas, nslabs); } pool_size = sizeof(*pool) + array_size(sizeof(*pool->areas), nareas); pool = kzalloc(pool_size, gfp); if (!pool) goto error; pool->areas = (void *)pool + sizeof(*pool); tlb_size = nslabs << IO_TLB_SHIFT; while (!(tlb = swiotlb_alloc_tlb(dev, tlb_size, phys_limit, gfp))) { if (nslabs <= minslabs) goto error_tlb; nslabs = ALIGN(nslabs >> 1, IO_TLB_SEGSIZE); nareas = limit_nareas(nareas, nslabs); tlb_size = nslabs << IO_TLB_SHIFT; } slot_order = get_order(array_size(sizeof(*pool->slots), nslabs)); pool->slots = (struct io_tlb_slot *) __get_free_pages(gfp, slot_order); if (!pool->slots) goto error_slots; swiotlb_init_io_tlb_pool(pool, page_to_phys(tlb), nslabs, true, nareas); return pool; error_slots: swiotlb_free_tlb(page_address(tlb), tlb_size); error_tlb: kfree(pool); error: return NULL; } /** * swiotlb_dyn_alloc() - dynamic memory pool allocation worker * @work: Pointer to dyn_alloc in struct io_tlb_mem. */ static void swiotlb_dyn_alloc(struct work_struct *work) { struct io_tlb_mem *mem = container_of(work, struct io_tlb_mem, dyn_alloc); struct io_tlb_pool *pool; pool = swiotlb_alloc_pool(NULL, IO_TLB_MIN_SLABS, default_nslabs, default_nareas, mem->phys_limit, GFP_KERNEL); if (!pool) { pr_warn_ratelimited("Failed to allocate new pool"); return; } add_mem_pool(mem, pool); } /** * swiotlb_dyn_free() - RCU callback to free a memory pool * @rcu: RCU head in the corresponding struct io_tlb_pool. */ static void swiotlb_dyn_free(struct rcu_head *rcu) { struct io_tlb_pool *pool = container_of(rcu, struct io_tlb_pool, rcu); size_t slots_size = array_size(sizeof(*pool->slots), pool->nslabs); size_t tlb_size = pool->end - pool->start; free_pages((unsigned long)pool->slots, get_order(slots_size)); swiotlb_free_tlb(pool->vaddr, tlb_size); kfree(pool); } /** * swiotlb_find_pool() - find the IO TLB pool for a physical address * @dev: Device which has mapped the DMA buffer. * @paddr: Physical address within the DMA buffer. * * Find the IO TLB memory pool descriptor which contains the given physical * address, if any. * * Return: Memory pool which contains @paddr, or %NULL if none. */ struct io_tlb_pool *swiotlb_find_pool(struct device *dev, phys_addr_t paddr) { struct io_tlb_mem *mem = dev->dma_io_tlb_mem; struct io_tlb_pool *pool; rcu_read_lock(); list_for_each_entry_rcu(pool, &mem->pools, node) { if (paddr >= pool->start && paddr < pool->end) goto out; } list_for_each_entry_rcu(pool, &dev->dma_io_tlb_pools, node) { if (paddr >= pool->start && paddr < pool->end) goto out; } pool = NULL; out: rcu_read_unlock(); return pool; } /** * swiotlb_del_pool() - remove an IO TLB pool from a device * @dev: Owning device. * @pool: Memory pool to be removed. */ static void swiotlb_del_pool(struct device *dev, struct io_tlb_pool *pool) { unsigned long flags; spin_lock_irqsave(&dev->dma_io_tlb_lock, flags); list_del_rcu(&pool->node); spin_unlock_irqrestore(&dev->dma_io_tlb_lock, flags); call_rcu(&pool->rcu, swiotlb_dyn_free); } #endif /* CONFIG_SWIOTLB_DYNAMIC */ /** * swiotlb_dev_init() - initialize swiotlb fields in &struct device * @dev: Device to be initialized. */ void swiotlb_dev_init(struct device *dev) { dev->dma_io_tlb_mem = &io_tlb_default_mem; #ifdef CONFIG_SWIOTLB_DYNAMIC INIT_LIST_HEAD(&dev->dma_io_tlb_pools); spin_lock_init(&dev->dma_io_tlb_lock); dev->dma_uses_io_tlb = false; #endif } /** * swiotlb_align_offset() - Get required offset into an IO TLB allocation. * @dev: Owning device. * @align_mask: Allocation alignment mask. * @addr: DMA address. * * Return the minimum offset from the start of an IO TLB allocation which is * required for a given buffer address and allocation alignment to keep the * device happy. * * First, the address bits covered by min_align_mask must be identical in the * original address and the bounce buffer address. High bits are preserved by * choosing a suitable IO TLB slot, but bits below IO_TLB_SHIFT require extra * padding bytes before the bounce buffer. * * Second, @align_mask specifies which bits of the first allocated slot must * be zero. This may require allocating additional padding slots, and then the * offset (in bytes) from the first such padding slot is returned. */ static unsigned int swiotlb_align_offset(struct device *dev, unsigned int align_mask, u64 addr) { return addr & dma_get_min_align_mask(dev) & (align_mask | (IO_TLB_SIZE - 1)); } /* * Bounce: copy the swiotlb buffer from or back to the original dma location */ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size, enum dma_data_direction dir) { struct io_tlb_pool *mem = swiotlb_find_pool(dev, tlb_addr); int index = (tlb_addr - mem->start) >> IO_TLB_SHIFT; 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 = mem->vaddr + tlb_addr - mem->start; int tlb_offset; if (orig_addr == INVALID_PHYS_ADDR) return; /* * It's valid for tlb_offset to be negative. This can happen when the * "offset" returned by swiotlb_align_offset() is non-zero, and the * tlb_addr is pointing within the first "offset" bytes of the second * or subsequent slots of the allocated swiotlb area. While it's not * valid for tlb_addr to be pointing within the first "offset" bytes * of the first slot, there's no way to check for such an error since * this function can't distinguish the first slot from the second and * subsequent slots. */ tlb_offset = (tlb_addr & (IO_TLB_SIZE - 1)) - swiotlb_align_offset(dev, 0, orig_addr); orig_addr += tlb_offset; alloc_size -= tlb_offset; if (size > alloc_size) { dev_WARN_ONCE(dev, 1, "Buffer overflow detected. Allocation size: %zu. Mapping size: %zu.\n", alloc_size, size); size = alloc_size; } if (PageHighMem(pfn_to_page(pfn))) { unsigned int offset = orig_addr & ~PAGE_MASK; struct page *page; unsigned int sz = 0; unsigned long flags; while (size) { sz = min_t(size_t, PAGE_SIZE - offset, size); local_irq_save(flags); page = pfn_to_page(pfn); if (dir == DMA_TO_DEVICE) memcpy_from_page(vaddr, page, offset, sz); else memcpy_to_page(page, offset, vaddr, sz); local_irq_restore(flags); size -= sz; pfn++; vaddr += sz; offset = 0; } } else if (dir == DMA_TO_DEVICE) { memcpy(vaddr, phys_to_virt(orig_addr), size); } else { memcpy(phys_to_virt(orig_addr), vaddr, size); } } static inline phys_addr_t slot_addr(phys_addr_t start, phys_addr_t idx) { return start + (idx << IO_TLB_SHIFT); } /* * Carefully handle integer overflow which can occur when boundary_mask == ~0UL. */ static inline unsigned long get_max_slots(unsigned long boundary_mask) { return (boundary_mask >> IO_TLB_SHIFT) + 1; } static unsigned int wrap_area_index(struct io_tlb_pool *mem, unsigned int index) { if (index >= mem->area_nslabs) return 0; return index; } /* * Track the total used slots with a global atomic value in order to have * correct information to determine the high water mark. The mem_used() * function gives imprecise results because there's no locking across * multiple areas. */ #ifdef CONFIG_DEBUG_FS static void inc_used_and_hiwater(struct io_tlb_mem *mem, unsigned int nslots) { unsigned long old_hiwater, new_used; new_used = atomic_long_add_return(nslots, &mem->total_used); old_hiwater = atomic_long_read(&mem->used_hiwater); do { if (new_used <= old_hiwater) break; } while (!atomic_long_try_cmpxchg(&mem->used_hiwater, &old_hiwater, new_used)); } static void dec_used(struct io_tlb_mem *mem, unsigned int nslots) { atomic_long_sub(nslots, &mem->total_used); } #else /* !CONFIG_DEBUG_FS */ static void inc_used_and_hiwater(struct io_tlb_mem *mem, unsigned int nslots) { } static void dec_used(struct io_tlb_mem *mem, unsigned int nslots) { } #endif /* CONFIG_DEBUG_FS */ #ifdef CONFIG_SWIOTLB_DYNAMIC #ifdef CONFIG_DEBUG_FS static void inc_transient_used(struct io_tlb_mem *mem, unsigned int nslots) { atomic_long_add(nslots, &mem->transient_nslabs); } static void dec_transient_used(struct io_tlb_mem *mem, unsigned int nslots) { atomic_long_sub(nslots, &mem->transient_nslabs); } #else /* !CONFIG_DEBUG_FS */ static void inc_transient_used(struct io_tlb_mem *mem, unsigned int nslots) { } static void dec_transient_used(struct io_tlb_mem *mem, unsigned int nslots) { } #endif /* CONFIG_DEBUG_FS */ #endif /* CONFIG_SWIOTLB_DYNAMIC */ /** * swiotlb_search_pool_area() - search one memory area in one pool * @dev: Device which maps the buffer. * @pool: Memory pool to be searched. * @area_index: Index of the IO TLB memory area to be searched. * @orig_addr: Original (non-bounced) IO buffer address. * @alloc_size: Total requested size of the bounce buffer, * including initial alignment padding. * @alloc_align_mask: Required alignment of the allocated buffer. * * Find a suitable sequence of IO TLB entries for the request and allocate * a buffer from the given IO TLB memory area. * This function takes care of locking. * * Return: Index of the first allocated slot, or -1 on error. */ static int swiotlb_search_pool_area(struct device *dev, struct io_tlb_pool *pool, int area_index, phys_addr_t orig_addr, size_t alloc_size, unsigned int alloc_align_mask) { struct io_tlb_area *area = pool->areas + area_index; unsigned long boundary_mask = dma_get_seg_boundary(dev); dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(dev, pool->start) & boundary_mask; unsigned long max_slots = get_max_slots(boundary_mask); unsigned int iotlb_align_mask = dma_get_min_align_mask(dev); unsigned int nslots = nr_slots(alloc_size), stride; unsigned int offset = swiotlb_align_offset(dev, 0, orig_addr); unsigned int index, slots_checked, count = 0, i; unsigned long flags; unsigned int slot_base; unsigned int slot_index; BUG_ON(!nslots); BUG_ON(area_index >= pool->nareas); /* * Historically, swiotlb allocations >= PAGE_SIZE were guaranteed to be * page-aligned in the absence of any other alignment requirements. * 'alloc_align_mask' was later introduced to specify the alignment * explicitly, however this is passed as zero for streaming mappings * and so we preserve the old behaviour there in case any drivers are * relying on it. */ if (!alloc_align_mask && !iotlb_align_mask && alloc_size >= PAGE_SIZE) alloc_align_mask = PAGE_SIZE - 1; /* * Ensure that the allocation is at least slot-aligned and update * 'iotlb_align_mask' to ignore bits that will be preserved when * offsetting into the allocation. */ alloc_align_mask |= (IO_TLB_SIZE - 1); iotlb_align_mask &= ~alloc_align_mask; /* * For mappings with an alignment requirement don't bother looping to * unaligned slots once we found an aligned one. */ stride = get_max_slots(max(alloc_align_mask, iotlb_align_mask)); spin_lock_irqsave(&area->lock, flags); if (unlikely(nslots > pool->area_nslabs - area->used)) goto not_found; slot_base = area_index * pool->area_nslabs; index = area->index; for (slots_checked = 0; slots_checked < pool->area_nslabs; ) { phys_addr_t tlb_addr; slot_index = slot_base + index; tlb_addr = slot_addr(tbl_dma_addr, slot_index); if ((tlb_addr & alloc_align_mask) || (orig_addr && (tlb_addr & iotlb_align_mask) != (orig_addr & iotlb_align_mask))) { index = wrap_area_index(pool, index + 1); slots_checked++; continue; } if (!iommu_is_span_boundary(slot_index, nslots, nr_slots(tbl_dma_addr), max_slots)) { if (pool->slots[slot_index].list >= nslots) goto found; } index = wrap_area_index(pool, index + stride); slots_checked += stride; } not_found: spin_unlock_irqrestore(&area->lock, flags); return -1; found: /* * If we find a slot that indicates we have 'nslots' number of * contiguous buffers, we allocate the buffers from that slot onwards * and set the list of free entries to '0' indicating unavailable. */ for (i = slot_index; i < slot_index + nslots; i++) { pool->slots[i].list = 0; pool->slots[i].alloc_size = alloc_size - (offset + ((i - slot_index) << IO_TLB_SHIFT)); } for (i = slot_index - 1; io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 && pool->slots[i].list; i--) pool->slots[i].list = ++count; /* * Update the indices to avoid searching in the next round. */ area->index = wrap_area_index(pool, index + nslots); area->used += nslots; spin_unlock_irqrestore(&area->lock, flags); inc_used_and_hiwater(dev->dma_io_tlb_mem, nslots); return slot_index; } #ifdef CONFIG_SWIOTLB_DYNAMIC /** * swiotlb_search_area() - search one memory area in all pools * @dev: Device which maps the buffer. * @start_cpu: Start CPU number. * @cpu_offset: Offset from @start_cpu. * @orig_addr: Original (non-bounced) IO buffer address. * @alloc_size: Total requested size of the bounce buffer, * including initial alignment padding. * @alloc_align_mask: Required alignment of the allocated buffer. * @retpool: Used memory pool, updated on return. * * Search one memory area in all pools for a sequence of slots that match the * allocation constraints. * * Return: Index of the first allocated slot, or -1 on error. */ static int swiotlb_search_area(struct device *dev, int start_cpu, int cpu_offset, phys_addr_t orig_addr, size_t alloc_size, unsigned int alloc_align_mask, struct io_tlb_pool **retpool) { struct io_tlb_mem *mem = dev->dma_io_tlb_mem; struct io_tlb_pool *pool; int area_index; int index = -1; rcu_read_lock(); list_for_each_entry_rcu(pool, &mem->pools, node) { if (cpu_offset >= pool->nareas) continue; area_index = (start_cpu + cpu_offset) & (pool->nareas - 1); index = swiotlb_search_pool_area(dev, pool, area_index, orig_addr, alloc_size, alloc_align_mask); if (index >= 0) { *retpool = pool; break; } } rcu_read_unlock(); return index; } /** * swiotlb_find_slots() - search for slots in the whole swiotlb * @dev: Device which maps the buffer. * @orig_addr: Original (non-bounced) IO buffer address. * @alloc_size: Total requested size of the bounce buffer, * including initial alignment padding. * @alloc_align_mask: Required alignment of the allocated buffer. * @retpool: Used memory pool, updated on return. * * Search through the whole software IO TLB to find a sequence of slots that * match the allocation constraints. * * Return: Index of the first allocated slot, or -1 on error. */ static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr, size_t alloc_size, unsigned int alloc_align_mask, struct io_tlb_pool **retpool) { struct io_tlb_mem *mem = dev->dma_io_tlb_mem; struct io_tlb_pool *pool; unsigned long nslabs; unsigned long flags; u64 phys_limit; int cpu, i; int index; if (alloc_size > IO_TLB_SEGSIZE * IO_TLB_SIZE) return -1; cpu = raw_smp_processor_id(); for (i = 0; i < default_nareas; ++i) { index = swiotlb_search_area(dev, cpu, i, orig_addr, alloc_size, alloc_align_mask, &pool); if (index >= 0) goto found; } if (!mem->can_grow) return -1; schedule_work(&mem->dyn_alloc); nslabs = nr_slots(alloc_size); phys_limit = min_not_zero(*dev->dma_mask, dev->bus_dma_limit); pool = swiotlb_alloc_pool(dev, nslabs, nslabs, 1, phys_limit, GFP_NOWAIT | __GFP_NOWARN); if (!pool) return -1; index = swiotlb_search_pool_area(dev, pool, 0, orig_addr, alloc_size, alloc_align_mask); if (index < 0) { swiotlb_dyn_free(&pool->rcu); return -1; } pool->transient = true; spin_lock_irqsave(&dev->dma_io_tlb_lock, flags); list_add_rcu(&pool->node, &dev->dma_io_tlb_pools); spin_unlock_irqrestore(&dev->dma_io_tlb_lock, flags); inc_transient_used(mem, pool->nslabs); found: WRITE_ONCE(dev->dma_uses_io_tlb, true); /* * The general barrier orders reads and writes against a presumed store * of the SWIOTLB buffer address by a device driver (to a driver private * data structure). It serves two purposes. * * First, the store to dev->dma_uses_io_tlb must be ordered before the * presumed store. This guarantees that the returned buffer address * cannot be passed to another CPU before updating dev->dma_uses_io_tlb. * * Second, the load from mem->pools must be ordered before the same * presumed store. This guarantees that the returned buffer address * cannot be observed by another CPU before an update of the RCU list * that was made by swiotlb_dyn_alloc() on a third CPU (cf. multicopy * atomicity). * * See also the comment in is_swiotlb_buffer(). */ smp_mb(); *retpool = pool; return index; } #else /* !CONFIG_SWIOTLB_DYNAMIC */ static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr, size_t alloc_size, unsigned int alloc_align_mask, struct io_tlb_pool **retpool) { struct io_tlb_pool *pool; int start, i; int index; *retpool = pool = &dev->dma_io_tlb_mem->defpool; i = start = raw_smp_processor_id() & (pool->nareas - 1); do { index = swiotlb_search_pool_area(dev, pool, i, orig_addr, alloc_size, alloc_align_mask); if (index >= 0) return index; if (++i >= pool->nareas) i = 0; } while (i != start); return -1; } #endif /* CONFIG_SWIOTLB_DYNAMIC */ #ifdef CONFIG_DEBUG_FS /** * mem_used() - get number of used slots in an allocator * @mem: Software IO TLB allocator. * * The result is accurate in this version of the function, because an atomic * counter is available if CONFIG_DEBUG_FS is set. * * Return: Number of used slots. */ static unsigned long mem_used(struct io_tlb_mem *mem) { return atomic_long_read(&mem->total_used); } #else /* !CONFIG_DEBUG_FS */ /** * mem_pool_used() - get number of used slots in a memory pool * @pool: Software IO TLB memory pool. * * The result is not accurate, see mem_used(). * * Return: Approximate number of used slots. */ static unsigned long mem_pool_used(struct io_tlb_pool *pool) { int i; unsigned long used = 0; for (i = 0; i < pool->nareas; i++) used += pool->areas[i].used; return used; } /** * mem_used() - get number of used slots in an allocator * @mem: Software IO TLB allocator. * * The result is not accurate, because there is no locking of individual * areas. * * Return: Approximate number of used slots. */ static unsigned long mem_used(struct io_tlb_mem *mem) { #ifdef CONFIG_SWIOTLB_DYNAMIC struct io_tlb_pool *pool; unsigned long used = 0; rcu_read_lock(); list_for_each_entry_rcu(pool, &mem->pools, node) used += mem_pool_used(pool); rcu_read_unlock(); return used; #else return mem_pool_used(&mem->defpool); #endif } #endif /* CONFIG_DEBUG_FS */ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, size_t mapping_size, size_t alloc_size, unsigned int alloc_align_mask, enum dma_data_direction dir, unsigned long attrs) { struct io_tlb_mem *mem = dev->dma_io_tlb_mem; unsigned int offset; struct io_tlb_pool *pool; unsigned int i; int index; phys_addr_t tlb_addr; unsigned short pad_slots; if (!mem || !mem->nslabs) { dev_warn_ratelimited(dev, "Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); return (phys_addr_t)DMA_MAPPING_ERROR; } if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n"); if (mapping_size > alloc_size) { dev_warn_once(dev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)", mapping_size, alloc_size); return (phys_addr_t)DMA_MAPPING_ERROR; } offset = swiotlb_align_offset(dev, alloc_align_mask, orig_addr); index = swiotlb_find_slots(dev, orig_addr, alloc_size + offset, alloc_align_mask, &pool); if (index == -1) { if (!(attrs & DMA_ATTR_NO_WARN)) dev_warn_ratelimited(dev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n", alloc_size, mem->nslabs, mem_used(mem)); return (phys_addr_t)DMA_MAPPING_ERROR; } /* * Save away the mapping from the original address to the DMA address. * This is needed when we sync the memory. Then we sync the buffer if * needed. */ pad_slots = offset >> IO_TLB_SHIFT; offset &= (IO_TLB_SIZE - 1); index += pad_slots; pool->slots[index].pad_slots = pad_slots; for (i = 0; i < nr_slots(alloc_size + offset); i++) pool->slots[index + i].orig_addr = slot_addr(orig_addr, i); tlb_addr = slot_addr(pool->start, index) + offset; /* * When the device is writing memory, i.e. dir == DMA_FROM_DEVICE, copy * the original buffer to the TLB buffer before initiating DMA in order * to preserve the original's data if the device does a partial write, * i.e. if the device doesn't overwrite the entire buffer. Preserving * the original data, even if it's garbage, is necessary to match * hardware behavior. Use of swiotlb is supposed to be transparent, * i.e. swiotlb must not corrupt memory by clobbering unwritten bytes. */ swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_TO_DEVICE); return tlb_addr; } static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr) { struct io_tlb_pool *mem = swiotlb_find_pool(dev, tlb_addr); unsigned long flags; unsigned int offset = swiotlb_align_offset(dev, 0, tlb_addr); int index, nslots, aindex; struct io_tlb_area *area; int count, i; index = (tlb_addr - offset - mem->start) >> IO_TLB_SHIFT; index -= mem->slots[index].pad_slots; nslots = nr_slots(mem->slots[index].alloc_size + offset); aindex = index / mem->area_nslabs; area = &mem->areas[aindex]; /* * Return the buffer to the free list by setting the corresponding * entries to indicate the number of contiguous entries available. * While returning the entries to the free list, we merge the entries * with slots below and above the pool being returned. */ BUG_ON(aindex >= mem->nareas); spin_lock_irqsave(&area->lock, flags); if (index + nslots < ALIGN(index + 1, IO_TLB_SEGSIZE)) count = mem->slots[index + nslots].list; else count = 0; /* * Step 1: return the slots to the free list, merging the slots with * superceeding slots */ for (i = index + nslots - 1; i >= index; i--) { mem->slots[i].list = ++count; mem->slots[i].orig_addr = INVALID_PHYS_ADDR; mem->slots[i].alloc_size = 0; mem->slots[i].pad_slots = 0; } /* * Step 2: merge the returned slots with the preceding slots, if * available (non zero) */ for (i = index - 1; io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 && mem->slots[i].list; i--) mem->slots[i].list = ++count; area->used -= nslots; spin_unlock_irqrestore(&area->lock, flags); dec_used(dev->dma_io_tlb_mem, nslots); } #ifdef CONFIG_SWIOTLB_DYNAMIC /** * swiotlb_del_transient() - delete a transient memory pool * @dev: Device which mapped the buffer. * @tlb_addr: Physical address within a bounce buffer. * * Check whether the address belongs to a transient SWIOTLB memory pool. * If yes, then delete the pool. * * Return: %true if @tlb_addr belonged to a transient pool that was released. */ static bool swiotlb_del_transient(struct device *dev, phys_addr_t tlb_addr) { struct io_tlb_pool *pool; pool = swiotlb_find_pool(dev, tlb_addr); if (!pool->transient) return false; dec_used(dev->dma_io_tlb_mem, pool->nslabs); swiotlb_del_pool(dev, pool); dec_transient_used(dev->dma_io_tlb_mem, pool->nslabs); return true; } #else /* !CONFIG_SWIOTLB_DYNAMIC */ static inline bool swiotlb_del_transient(struct device *dev, phys_addr_t tlb_addr) { return false; } #endif /* CONFIG_SWIOTLB_DYNAMIC */ /* * tlb_addr is the physical address of the bounce buffer to unmap. */ void swiotlb_tbl_unmap_single(struct device *dev, phys_addr_t tlb_addr, size_t mapping_size, enum dma_data_direction dir, unsigned long attrs) { /* * First, sync the memory before unmapping the entry */ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_FROM_DEVICE); if (swiotlb_del_transient(dev, tlb_addr)) return; swiotlb_release_slots(dev, tlb_addr); } void swiotlb_sync_single_for_device(struct device *dev, phys_addr_t tlb_addr, size_t size, enum dma_data_direction dir) { if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) swiotlb_bounce(dev, tlb_addr, size, DMA_TO_DEVICE); else BUG_ON(dir != DMA_FROM_DEVICE); } void swiotlb_sync_single_for_cpu(struct device *dev, phys_addr_t tlb_addr, size_t size, enum dma_data_direction dir) { if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) swiotlb_bounce(dev, tlb_addr, size, DMA_FROM_DEVICE); else BUG_ON(dir != DMA_TO_DEVICE); } /* * Create a swiotlb mapping for the buffer at @paddr, and in case of DMAing * to the device copy the data into it as well. */ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size, enum dma_data_direction dir, unsigned long attrs) { phys_addr_t swiotlb_addr; dma_addr_t dma_addr; trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size); swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, 0, dir, attrs); if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR) return DMA_MAPPING_ERROR; /* Ensure that the address returned is DMA'ble */ dma_addr = phys_to_dma_unencrypted(dev, swiotlb_addr); if (unlikely(!dma_capable(dev, dma_addr, size, true))) { swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); dev_WARN_ONCE(dev, 1, "swiotlb addr %pad+%zu overflow (mask %llx, bus limit %llx).\n", &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit); return DMA_MAPPING_ERROR; } if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) arch_sync_dma_for_device(swiotlb_addr, size, dir); return dma_addr; } size_t swiotlb_max_mapping_size(struct device *dev) { int min_align_mask = dma_get_min_align_mask(dev); int min_align = 0; /* * swiotlb_find_slots() skips slots according to * min align mask. This affects max mapping size. * Take it into acount here. */ if (min_align_mask) min_align = roundup(min_align_mask, IO_TLB_SIZE); return ((size_t)IO_TLB_SIZE) * IO_TLB_SEGSIZE - min_align; } /** * is_swiotlb_allocated() - check if the default software IO TLB is initialized */ bool is_swiotlb_allocated(void) { return io_tlb_default_mem.nslabs; } bool is_swiotlb_active(struct device *dev) { struct io_tlb_mem *mem = dev->dma_io_tlb_mem; return mem && mem->nslabs; } /** * default_swiotlb_base() - get the base address of the default SWIOTLB * * Get the lowest physical address used by the default software IO TLB pool. */ phys_addr_t default_swiotlb_base(void) { #ifdef CONFIG_SWIOTLB_DYNAMIC io_tlb_default_mem.can_grow = false; #endif return io_tlb_default_mem.defpool.start; } /** * default_swiotlb_limit() - get the address limit of the default SWIOTLB * * Get the highest physical address used by the default software IO TLB pool. */ phys_addr_t default_swiotlb_limit(void) { #ifdef CONFIG_SWIOTLB_DYNAMIC return io_tlb_default_mem.phys_limit; #else return io_tlb_default_mem.defpool.end - 1; #endif } #ifdef CONFIG_DEBUG_FS #ifdef CONFIG_SWIOTLB_DYNAMIC static unsigned long mem_transient_used(struct io_tlb_mem *mem) { return atomic_long_read(&mem->transient_nslabs); } static int io_tlb_transient_used_get(void *data, u64 *val) { struct io_tlb_mem *mem = data; *val = mem_transient_used(mem); return 0; } DEFINE_DEBUGFS_ATTRIBUTE(fops_io_tlb_transient_used, io_tlb_transient_used_get, NULL, "%llu\n"); #endif /* CONFIG_SWIOTLB_DYNAMIC */ static int io_tlb_used_get(void *data, u64 *val) { struct io_tlb_mem *mem = data; *val = mem_used(mem); return 0; } static int io_tlb_hiwater_get(void *data, u64 *val) { struct io_tlb_mem *mem = data; *val = atomic_long_read(&mem->used_hiwater); return 0; } static int io_tlb_hiwater_set(void *data, u64 val) { struct io_tlb_mem *mem = data; /* Only allow setting to zero */ if (val != 0) return -EINVAL; atomic_long_set(&mem->used_hiwater, val); return 0; } DEFINE_DEBUGFS_ATTRIBUTE(fops_io_tlb_used, io_tlb_used_get, NULL, "%llu\n"); DEFINE_DEBUGFS_ATTRIBUTE(fops_io_tlb_hiwater, io_tlb_hiwater_get, io_tlb_hiwater_set, "%llu\n"); static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem, const char *dirname) { mem->debugfs = debugfs_create_dir(dirname, io_tlb_default_mem.debugfs); if (!mem->nslabs) return; debugfs_create_ulong("io_tlb_nslabs", 0400, mem->debugfs, &mem->nslabs); debugfs_create_file("io_tlb_used", 0400, mem->debugfs, mem, &fops_io_tlb_used); debugfs_create_file("io_tlb_used_hiwater", 0600, mem->debugfs, mem, &fops_io_tlb_hiwater); #ifdef CONFIG_SWIOTLB_DYNAMIC debugfs_create_file("io_tlb_transient_nslabs", 0400, mem->debugfs, mem, &fops_io_tlb_transient_used); #endif } static int __init swiotlb_create_default_debugfs(void) { swiotlb_create_debugfs_files(&io_tlb_default_mem, "swiotlb"); return 0; } late_initcall(swiotlb_create_default_debugfs); #else /* !CONFIG_DEBUG_FS */ static inline void swiotlb_create_debugfs_files(struct io_tlb_mem *mem, const char *dirname) { } #endif /* CONFIG_DEBUG_FS */ #ifdef CONFIG_DMA_RESTRICTED_POOL struct page *swiotlb_alloc(struct device *dev, size_t size) { struct io_tlb_mem *mem = dev->dma_io_tlb_mem; struct io_tlb_pool *pool; phys_addr_t tlb_addr; unsigned int align; int index; if (!mem) return NULL; align = (1 << (get_order(size) + PAGE_SHIFT)) - 1; index = swiotlb_find_slots(dev, 0, size, align, &pool); if (index == -1) return NULL; tlb_addr = slot_addr(pool->start, index); if (unlikely(!PAGE_ALIGNED(tlb_addr))) { dev_WARN_ONCE(dev, 1, "Cannot allocate pages from non page-aligned swiotlb addr 0x%pa.\n", &tlb_addr); swiotlb_release_slots(dev, tlb_addr); return NULL; } return pfn_to_page(PFN_DOWN(tlb_addr)); } bool swiotlb_free(struct device *dev, struct page *page, size_t size) { phys_addr_t tlb_addr = page_to_phys(page); if (!is_swiotlb_buffer(dev, tlb_addr)) return false; swiotlb_release_slots(dev, tlb_addr); return true; } static int rmem_swiotlb_device_init(struct reserved_mem *rmem, struct device *dev) { struct io_tlb_mem *mem = rmem->priv; unsigned long nslabs = rmem->size >> IO_TLB_SHIFT; /* Set Per-device io tlb area to one */ unsigned int nareas = 1; if (PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { dev_err(dev, "Restricted DMA pool must be accessible within the linear mapping."); return -EINVAL; } /* * Since multiple devices can share the same pool, the private data, * io_tlb_mem struct, will be initialized by the first device attached * to it. */ if (!mem) { struct io_tlb_pool *pool; mem = kzalloc(sizeof(*mem), GFP_KERNEL); if (!mem) return -ENOMEM; pool = &mem->defpool; pool->slots = kcalloc(nslabs, sizeof(*pool->slots), GFP_KERNEL); if (!pool->slots) { kfree(mem); return -ENOMEM; } pool->areas = kcalloc(nareas, sizeof(*pool->areas), GFP_KERNEL); if (!pool->areas) { kfree(pool->slots); kfree(mem); return -ENOMEM; } set_memory_decrypted((unsigned long)phys_to_virt(rmem->base), rmem->size >> PAGE_SHIFT); swiotlb_init_io_tlb_pool(pool, rmem->base, nslabs, false, nareas); mem->force_bounce = true; mem->for_alloc = true; #ifdef CONFIG_SWIOTLB_DYNAMIC spin_lock_init(&mem->lock); INIT_LIST_HEAD_RCU(&mem->pools); #endif add_mem_pool(mem, pool); rmem->priv = mem; swiotlb_create_debugfs_files(mem, rmem->name); } dev->dma_io_tlb_mem = mem; return 0; } static void rmem_swiotlb_device_release(struct reserved_mem *rmem, struct device *dev) { dev->dma_io_tlb_mem = &io_tlb_default_mem; } static const struct reserved_mem_ops rmem_swiotlb_ops = { .device_init = rmem_swiotlb_device_init, .device_release = rmem_swiotlb_device_release, }; static int __init rmem_swiotlb_setup(struct reserved_mem *rmem) { unsigned long node = rmem->fdt_node; if (of_get_flat_dt_prop(node, "reusable", NULL) || of_get_flat_dt_prop(node, "linux,cma-default", NULL) || of_get_flat_dt_prop(node, "linux,dma-default", NULL) || of_get_flat_dt_prop(node, "no-map", NULL)) return -EINVAL; rmem->ops = &rmem_swiotlb_ops; pr_info("Reserved memory: created restricted DMA pool at %pa, size %ld MiB\n", &rmem->base, (unsigned long)rmem->size / SZ_1M); return 0; } RESERVEDMEM_OF_DECLARE(dma, "restricted-dma-pool", rmem_swiotlb_setup); #endif /* CONFIG_DMA_RESTRICTED_POOL */