diff options
Diffstat (limited to 'kernel/dma/swiotlb.c')
| -rw-r--r-- | kernel/dma/swiotlb.c | 1253 |
1 files changed, 1028 insertions, 225 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index a34c38bbe28f..a547c7693135 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -35,6 +35,7 @@ #include <linux/memblock.h> #include <linux/mm.h> #include <linux/pfn.h> +#include <linux/rculist.h> #include <linux/scatterlist.h> #include <linux/set_memory.h> #include <linux/spinlock.h> @@ -60,20 +61,41 @@ */ #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 int list; + unsigned short list; + unsigned short pad_slots; }; static bool swiotlb_force_bounce; static bool swiotlb_force_disable; -struct io_tlb_mem io_tlb_default_mem; +#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 */ -phys_addr_t swiotlb_unencrypted_base; +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; @@ -117,9 +139,16 @@ static bool round_up_default_nslabs(void) 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) { - /* use a single area when non is specified */ if (!nareas) nareas = 1; else if (!is_power_of_2(nareas)) @@ -133,6 +162,23 @@ static void swiotlb_adjust_nareas(unsigned int nareas) (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) { @@ -156,14 +202,6 @@ setup_io_tlb_npages(char *str) } early_param("swiotlb", setup_io_tlb_npages); -unsigned int swiotlb_max_segment(void) -{ - if (!io_tlb_default_mem.nslabs) - return 0; - return rounddown(io_tlb_default_mem.nslabs << IO_TLB_SHIFT, PAGE_SIZE); -} -EXPORT_SYMBOL_GPL(swiotlb_max_segment); - unsigned long swiotlb_size_or_default(void) { return default_nslabs << IO_TLB_SHIFT; @@ -188,7 +226,7 @@ void __init swiotlb_adjust_size(unsigned long size) void swiotlb_print_info(void) { - struct io_tlb_mem *mem = &io_tlb_default_mem; + struct io_tlb_pool *mem = &io_tlb_default_mem.defpool; if (!mem->nslabs) { pr_warn("No low mem\n"); @@ -210,34 +248,6 @@ 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 @@ -245,24 +255,17 @@ static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes) */ void __init swiotlb_update_mem_attributes(void) { - struct io_tlb_mem *mem = &io_tlb_default_mem; - void *vaddr; + struct io_tlb_pool *mem = &io_tlb_default_mem.defpool; unsigned long bytes; if (!mem->nslabs || mem->late_alloc) return; - vaddr = phys_to_virt(mem->start); bytes = PAGE_ALIGN(mem->nslabs << IO_TLB_SHIFT); - set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT); - - mem->vaddr = swiotlb_mem_remap(mem, bytes); - if (!mem->vaddr) - mem->vaddr = vaddr; + set_memory_decrypted((unsigned long)mem->vaddr, bytes >> PAGE_SHIFT); } -static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, - unsigned long nslabs, unsigned int flags, - bool late_alloc, unsigned int nareas) +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; @@ -274,8 +277,6 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, mem->nareas = nareas; mem->area_nslabs = nslabs / mem->nareas; - mem->force_bounce = swiotlb_force_bounce || (flags & SWIOTLB_FORCE); - for (i = 0; i < mem->nareas; i++) { spin_lock_init(&mem->areas[i].lock); mem->areas[i].index = 0; @@ -283,24 +284,37 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, } for (i = 0; i < mem->nslabs; i++) { - mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(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; } - /* - * 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; } -static void *swiotlb_memblock_alloc(unsigned long nslabs, unsigned int flags, +/** + * 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); @@ -338,8 +352,9 @@ static void *swiotlb_memblock_alloc(unsigned long nslabs, unsigned int flags, void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags, int (*remap)(void *tlb, unsigned long nslabs)) { - struct io_tlb_mem *mem = &io_tlb_default_mem; + struct io_tlb_pool *mem = &io_tlb_default_mem.defpool; unsigned long nslabs; + unsigned int nareas; size_t alloc_size; void *tlb; @@ -348,18 +363,28 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags, if (swiotlb_force_disable) return; - /* - * default_nslabs maybe changed when adjust area number. - * So allocate bounce buffer after adjusting area number. - */ + 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) { @@ -377,14 +402,14 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags, } mem->areas = memblock_alloc(array_size(sizeof(struct io_tlb_area), - default_nareas), SMP_CACHE_BYTES); + nareas), SMP_CACHE_BYTES); if (!mem->areas) { pr_warn("%s: Failed to allocate mem->areas.\n", __func__); return; } - swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, flags, false, - default_nareas); + 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(); @@ -403,16 +428,36 @@ void __init swiotlb_init(bool addressing_limit, unsigned int flags) int swiotlb_init_late(size_t size, gfp_t gfp_mask, int (*remap)(void *tlb, unsigned long nslabs)) { - struct io_tlb_mem *mem = &io_tlb_default_mem; + 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 = zone_dma_limit; + else if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp_mask & __GFP_DMA32)) + io_tlb_default_mem.phys_limit = max(DMA_BIT_MASK(32), zone_dma_limit); + 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; @@ -447,11 +492,8 @@ retry: (PAGE_SIZE << order) >> 20); } - if (!default_nareas) - swiotlb_adjust_nareas(num_possible_cpus()); - - area_order = get_order(array_size(sizeof(*mem->areas), - default_nareas)); + 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) @@ -464,8 +506,9 @@ retry: set_memory_decrypted((unsigned long)vstart, (nslabs << IO_TLB_SHIFT) >> PAGE_SHIFT); - swiotlb_init_io_tlb_mem(mem, virt_to_phys(vstart), nslabs, 0, true, - default_nareas); + 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; @@ -479,7 +522,7 @@ error_area: void __init swiotlb_exit(void) { - struct io_tlb_mem *mem = &io_tlb_default_mem; + struct io_tlb_pool *mem = &io_tlb_default_mem.defpool; unsigned long tbl_vaddr; size_t tbl_size, slots_size; unsigned int area_order; @@ -512,47 +555,330 @@ void __init swiotlb_exit(void) memset(mem, 0, sizeof(*mem)); } -/* - * Return the offset into a iotlb slot required to keep the device happy. +#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 <= zone_dma_limit) + 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. This function is for use only when the dev is known to + * be using swiotlb. Use swiotlb_find_pool() for the more general case + * when this condition is not met. + * + * 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 unsigned int swiotlb_align_offset(struct device *dev, u64 addr) +static void swiotlb_del_pool(struct device *dev, struct io_tlb_pool *pool) { - return addr & dma_get_min_align_mask(dev) & (IO_TLB_SIZE - 1); + 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) + enum dma_data_direction dir, struct io_tlb_pool *mem) { - struct io_tlb_mem *mem = dev->dma_io_tlb_mem; 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; - unsigned int tlb_offset, orig_addr_offset; + int tlb_offset; if (orig_addr == INVALID_PHYS_ADDR) return; - tlb_offset = tlb_addr & (IO_TLB_SIZE - 1); - orig_addr_offset = swiotlb_align_offset(dev, orig_addr); - if (tlb_offset < orig_addr_offset) { - dev_WARN_ONCE(dev, 1, - "Access before mapping start detected. orig offset %u, requested offset %u.\n", - orig_addr_offset, tlb_offset); - return; - } - - tlb_offset -= orig_addr_offset; - if (tlb_offset > alloc_size) { - dev_WARN_ONCE(dev, 1, - "Buffer overflow detected. Allocation size: %zu. Mapping size: %zu+%u.\n", - alloc_size, size, tlb_offset); - 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; @@ -603,12 +929,10 @@ static inline phys_addr_t slot_addr(phys_addr_t start, phys_addr_t idx) */ static inline unsigned long get_max_slots(unsigned long boundary_mask) { - if (boundary_mask == ~0UL) - return 1UL << (BITS_PER_LONG - IO_TLB_SHIFT); - return nr_slots(boundary_mask + 1); + return (boundary_mask >> IO_TLB_SHIFT) + 1; } -static unsigned int wrap_area_index(struct io_tlb_mem *mem, unsigned int index) +static unsigned int wrap_area_index(struct io_tlb_pool *mem, unsigned int index) { if (index >= mem->area_nslabs) return 0; @@ -616,138 +940,442 @@ static unsigned int wrap_area_index(struct io_tlb_mem *mem, unsigned int index) } /* - * Find a suitable number of IO TLB entries size that will fit this request and - * allocate a buffer from that IO TLB pool. + * 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_do_find_slots(struct device *dev, int area_index, - phys_addr_t orig_addr, size_t alloc_size, +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_mem *mem = dev->dma_io_tlb_mem; - struct io_tlb_area *area = mem->areas + area_index; + 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, mem->start) & boundary_mask; + 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) & ~(IO_TLB_SIZE - 1); + unsigned int iotlb_align_mask = dma_get_min_align_mask(dev); unsigned int nslots = nr_slots(alloc_size), stride; - unsigned int index, wrap, count = 0, i; - unsigned int offset = swiotlb_align_offset(dev, orig_addr); + 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 >= mem->nareas); + 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. For allocations of - * PAGE_SIZE or larger only look for page aligned allocations. + * unaligned slots once we found an aligned one. */ - stride = (iotlb_align_mask >> IO_TLB_SHIFT) + 1; - if (alloc_size >= PAGE_SIZE) - stride = max(stride, stride << (PAGE_SHIFT - IO_TLB_SHIFT)); - stride = max(stride, (alloc_align_mask >> IO_TLB_SHIFT) + 1); + stride = get_max_slots(max(alloc_align_mask, iotlb_align_mask)); spin_lock_irqsave(&area->lock, flags); - if (unlikely(nslots > mem->area_nslabs - area->used)) + if (unlikely(nslots > pool->area_nslabs - area->used)) goto not_found; - slot_base = area_index * mem->area_nslabs; - index = wrap = wrap_area_index(mem, ALIGN(area->index, stride)); + slot_base = area_index * pool->area_nslabs; + index = area->index; + + for (slots_checked = 0; slots_checked < pool->area_nslabs; ) { + phys_addr_t tlb_addr; - do { slot_index = slot_base + index; + tlb_addr = slot_addr(tbl_dma_addr, slot_index); - if (orig_addr && - (slot_addr(tbl_dma_addr, slot_index) & - iotlb_align_mask) != (orig_addr & iotlb_align_mask)) { - index = wrap_area_index(mem, index + 1); + 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 we find a slot that indicates we have 'nslots' number of - * contiguous buffers, we allocate the buffers from that slot - * and mark the entries as '0' indicating unavailable. - */ if (!iommu_is_span_boundary(slot_index, nslots, nr_slots(tbl_dma_addr), max_slots)) { - if (mem->slots[slot_index].list >= nslots) + if (pool->slots[slot_index].list >= nslots) goto found; } - index = wrap_area_index(mem, index + stride); - } while (index != wrap); + 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++) { - mem->slots[i].list = 0; - mem->slots[i].alloc_size = alloc_size - (offset + + 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 && - mem->slots[i].list; i--) - mem->slots[i].list = ++count; + pool->slots[i].list; i--) + pool->slots[i].list = ++count; /* * Update the indices to avoid searching in the next round. */ - if (index + nslots < mem->area_nslabs) - area->index = index + nslots; - else - area->index = 0; + 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) + size_t alloc_size, unsigned int alloc_align_mask, + struct io_tlb_pool **retpool) { struct io_tlb_mem *mem = dev->dma_io_tlb_mem; - int start = raw_smp_processor_id() & (mem->nareas - 1); - int i = start, index; + 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); + 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 swiotlb_find_pool(). + */ + 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_do_find_slots(dev, i, orig_addr, alloc_size, - alloc_align_mask); + index = swiotlb_search_pool_area(dev, pool, i, orig_addr, + alloc_size, alloc_align_mask); if (index >= 0) return index; - if (++i >= mem->nareas) + 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 < mem->nareas; i++) - used += mem->areas[i].used; + 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 */ + +/** + * swiotlb_tbl_map_single() - bounce buffer map a single contiguous physical area + * @dev: Device which maps the buffer. + * @orig_addr: Original (non-bounced) physical IO buffer address + * @mapping_size: Requested size of the actual bounce buffer, excluding + * any pre- or post-padding for alignment + * @alloc_align_mask: Required start and end alignment of the allocated buffer + * @dir: DMA direction + * @attrs: Optional DMA attributes for the map operation + * + * Find and allocate a suitable sequence of IO TLB slots for the request. + * The allocated space starts at an alignment specified by alloc_align_mask, + * and the size of the allocated space is rounded up so that the total amount + * of allocated space is a multiple of (alloc_align_mask + 1). If + * alloc_align_mask is zero, the allocated space may be at any alignment and + * the size is not rounded up. + * + * The returned address is within the allocated space and matches the bits + * of orig_addr that are specified in the DMA min_align_mask for the device. As + * such, this returned address may be offset from the beginning of the allocated + * space. The bounce buffer space starting at the returned address for + * mapping_size bytes is initialized to the contents of the original IO buffer + * area. Any pre-padding (due to an offset) and any post-padding (due to + * rounding-up the size) is not initialized. + */ 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) + size_t mapping_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 = swiotlb_align_offset(dev, orig_addr); + unsigned int offset; + struct io_tlb_pool *pool; unsigned int i; + size_t size; int index; phys_addr_t tlb_addr; + unsigned short pad_slots; if (!mem || !mem->nslabs) { dev_warn_ratelimited(dev, @@ -758,52 +1386,73 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, 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; - } + /* + * The default swiotlb memory pool is allocated with PAGE_SIZE + * alignment. If a mapping is requested with larger alignment, + * the mapping may be unable to use the initial slot(s) in all + * sets of IO_TLB_SEGSIZE slots. In such case, a mapping request + * of or near the maximum mapping size would always fail. + */ + dev_WARN_ONCE(dev, alloc_align_mask > ~PAGE_MASK, + "Alloc alignment may prevent fulfilling requests with max mapping_size\n"); - index = swiotlb_find_slots(dev, orig_addr, - alloc_size + offset, alloc_align_mask); + offset = swiotlb_align_offset(dev, alloc_align_mask, orig_addr); + size = ALIGN(mapping_size + offset, alloc_align_mask + 1); + index = swiotlb_find_slots(dev, orig_addr, size, 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)); + size, mem->nslabs, mem_used(mem)); return (phys_addr_t)DMA_MAPPING_ERROR; } /* + * If dma_skip_sync was set, reset it on first SWIOTLB buffer + * mapping to always sync SWIOTLB buffers. + */ + dma_reset_need_sync(dev); + + /* * 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. */ - for (i = 0; i < nr_slots(alloc_size + offset); i++) - mem->slots[index + i].orig_addr = slot_addr(orig_addr, i); - tlb_addr = slot_addr(mem->start, index) + offset; + 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(size) - pad_slots); i++) + pool->slots[index + i].orig_addr = slot_addr(orig_addr, i); + tlb_addr = slot_addr(pool->start, index) + offset; /* - * When dir == DMA_FROM_DEVICE we could omit the copy from the orig - * to the tlb buffer, if we knew for sure the device will - * overwrite the entire current content. But we don't. Thus - * unconditional bounce may prevent leaking swiotlb content (i.e. - * kernel memory) to user-space. + * 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); + swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_TO_DEVICE, pool); return tlb_addr; } -static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr) +static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr, + struct io_tlb_pool *mem) { - struct io_tlb_mem *mem = dev->dma_io_tlb_mem; unsigned long flags; - unsigned int offset = swiotlb_align_offset(dev, tlb_addr); - int index = (tlb_addr - offset - mem->start) >> IO_TLB_SHIFT; - int nslots = nr_slots(mem->slots[index].alloc_size + offset); - int aindex = index / mem->area_nslabs; - struct io_tlb_area *area = &mem->areas[aindex]; + 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. @@ -826,6 +1475,7 @@ static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr) 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; } /* @@ -838,39 +1488,81 @@ static void swiotlb_release_slots(struct device *dev, phys_addr_t tlb_addr) 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. + * @pool: Pointer to the transient memory pool to be checked and deleted. + * + * 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) +{ + 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, struct io_tlb_pool *pool) +{ + 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) +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, struct io_tlb_pool *pool) { /* * 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); + swiotlb_bounce(dev, tlb_addr, mapping_size, + DMA_FROM_DEVICE, pool); - swiotlb_release_slots(dev, tlb_addr); + if (swiotlb_del_transient(dev, tlb_addr, pool)) + return; + swiotlb_release_slots(dev, tlb_addr, pool); } -void swiotlb_sync_single_for_device(struct device *dev, phys_addr_t tlb_addr, - size_t size, enum dma_data_direction dir) +void __swiotlb_sync_single_for_device(struct device *dev, phys_addr_t tlb_addr, + size_t size, enum dma_data_direction dir, + struct io_tlb_pool *pool) { if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) - swiotlb_bounce(dev, tlb_addr, size, DMA_TO_DEVICE); + swiotlb_bounce(dev, tlb_addr, size, DMA_TO_DEVICE, pool); 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) +void __swiotlb_sync_single_for_cpu(struct device *dev, phys_addr_t tlb_addr, + size_t size, enum dma_data_direction dir, + struct io_tlb_pool *pool) { if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) - swiotlb_bounce(dev, tlb_addr, size, DMA_FROM_DEVICE); + swiotlb_bounce(dev, tlb_addr, size, DMA_FROM_DEVICE, pool); else BUG_ON(dir != DMA_TO_DEVICE); } @@ -887,16 +1579,16 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size, trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size); - swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, 0, dir, - attrs); + swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, 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); + __swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, dir, + attrs | DMA_ATTR_SKIP_CPU_SYNC, + swiotlb_find_pool(dev, swiotlb_addr)); 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); @@ -924,20 +1616,98 @@ size_t swiotlb_max_mapping_size(struct device *dev) 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; } -EXPORT_SYMBOL_GPL(is_swiotlb_active); + +/** + * 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) { - *val = mem_used(&io_tlb_default_mem); + 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) @@ -947,36 +1717,58 @@ static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem, return; debugfs_create_ulong("io_tlb_nslabs", 0400, mem->debugfs, &mem->nslabs); - debugfs_create_file("io_tlb_used", 0400, mem->debugfs, NULL, + 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 __maybe_unused swiotlb_create_default_debugfs(void) +static int __init swiotlb_create_default_debugfs(void) { swiotlb_create_debugfs_files(&io_tlb_default_mem, "swiotlb"); return 0; } -#ifdef CONFIG_DEBUG_FS late_initcall(swiotlb_create_default_debugfs); -#endif + +#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; - index = swiotlb_find_slots(dev, 0, size, 0); + 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(mem->start, index); + 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, pool); + return NULL; + } return pfn_to_page(PFN_DOWN(tlb_addr)); } @@ -984,11 +1776,13 @@ struct page *swiotlb_alloc(struct device *dev, size_t size) bool swiotlb_free(struct device *dev, struct page *page, size_t size) { phys_addr_t tlb_addr = page_to_phys(page); + struct io_tlb_pool *pool; - if (!is_swiotlb_buffer(dev, tlb_addr)) + pool = swiotlb_find_pool(dev, tlb_addr); + if (!pool) return false; - swiotlb_release_slots(dev, tlb_addr); + swiotlb_release_slots(dev, tlb_addr, pool); return true; } @@ -1002,35 +1796,49 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem, /* 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; - mem->slots = kcalloc(nslabs, sizeof(*mem->slots), GFP_KERNEL); - if (!mem->slots) { + pool->slots = kcalloc(nslabs, sizeof(*pool->slots), GFP_KERNEL); + if (!pool->slots) { kfree(mem); return -ENOMEM; } - mem->areas = kcalloc(nareas, sizeof(*mem->areas), + pool->areas = kcalloc(nareas, sizeof(*pool->areas), GFP_KERNEL); - if (!mem->areas) { - kfree(mem->slots); + 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_mem(mem, rmem->base, nslabs, SWIOTLB_FORCE, - false, nareas); + 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; @@ -1063,11 +1871,6 @@ static int __init rmem_swiotlb_setup(struct reserved_mem *rmem) of_get_flat_dt_prop(node, "no-map", NULL)) return -EINVAL; - if (PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { - pr_err("Restricted DMA pool must be accessible within the linear mapping."); - 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); |