| /* |
| * 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 <Asit.K.Mallick@intel.com> |
| * Copyright (C) 2000 Goutham Rao <goutham.rao@intel.com> |
| * Copyright (C) 2000, 2003 Hewlett-Packard Co |
| * David Mosberger-Tang <davidm@hpl.hp.com> |
| * |
| * 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 <linux/cache.h> |
| #include <linux/dma-direct.h> |
| #include <linux/mm.h> |
| #include <linux/export.h> |
| #include <linux/spinlock.h> |
| #include <linux/string.h> |
| #include <linux/swiotlb.h> |
| #include <linux/pfn.h> |
| #include <linux/types.h> |
| #include <linux/ctype.h> |
| #include <linux/highmem.h> |
| #include <linux/gfp.h> |
| #include <linux/scatterlist.h> |
| #include <linux/mem_encrypt.h> |
| #include <linux/set_memory.h> |
| #ifdef CONFIG_DEBUG_FS |
| #include <linux/debugfs.h> |
| #endif |
| |
| #include <asm/io.h> |
| #include <asm/dma.h> |
| |
| #include <linux/init.h> |
| #include <linux/memblock.h> |
| #include <linux/iommu-helper.h> |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/swiotlb.h> |
| |
| #define OFFSET(val,align) ((unsigned long) \ |
| ( (val) & ( (align) - 1))) |
| |
| #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) |
| |
| enum swiotlb_force swiotlb_force; |
| |
| /* |
| * Used to do a quick range check in swiotlb_tbl_unmap_single and |
| * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this |
| * API. |
| */ |
| phys_addr_t io_tlb_start, io_tlb_end; |
| |
| /* |
| * The number of IO TLB blocks (in groups of 64) between io_tlb_start and |
| * io_tlb_end. This is command line adjustable via setup_io_tlb_npages. |
| */ |
| static unsigned long io_tlb_nslabs; |
| |
| /* |
| * The number of used IO TLB block |
| */ |
| static unsigned long io_tlb_used; |
| |
| /* |
| * This is a free list describing the number of free entries available from |
| * each index |
| */ |
| static unsigned int *io_tlb_list; |
| static unsigned int io_tlb_index; |
| |
| /* |
| * Max segment that we can provide which (if pages are contingous) will |
| * not be bounced (unless SWIOTLB_FORCE is set). |
| */ |
| unsigned int max_segment; |
| |
| /* |
| * We need to save away the original address corresponding to a mapped entry |
| * for the sync operations. |
| */ |
| #define INVALID_PHYS_ADDR (~(phys_addr_t)0) |
| static phys_addr_t *io_tlb_orig_addr; |
| |
| /* |
| * Protect the above data structures in the map and unmap calls |
| */ |
| static DEFINE_SPINLOCK(io_tlb_lock); |
| |
| static int late_alloc; |
| |
| static int __init |
| setup_io_tlb_npages(char *str) |
| { |
| if (isdigit(*str)) { |
| io_tlb_nslabs = simple_strtoul(str, &str, 0); |
| /* avoid tail segment of size < IO_TLB_SEGSIZE */ |
| io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); |
| } |
| if (*str == ',') |
| ++str; |
| if (!strcmp(str, "force")) { |
| swiotlb_force = SWIOTLB_FORCE; |
| } else if (!strcmp(str, "noforce")) { |
| swiotlb_force = SWIOTLB_NO_FORCE; |
| io_tlb_nslabs = 1; |
| } |
| |
| return 0; |
| } |
| early_param("swiotlb", setup_io_tlb_npages); |
| |
| unsigned long swiotlb_nr_tbl(void) |
| { |
| return io_tlb_nslabs; |
| } |
| EXPORT_SYMBOL_GPL(swiotlb_nr_tbl); |
| |
| unsigned int swiotlb_max_segment(void) |
| { |
| return max_segment; |
| } |
| EXPORT_SYMBOL_GPL(swiotlb_max_segment); |
| |
| void swiotlb_set_max_segment(unsigned int val) |
| { |
| if (swiotlb_force == SWIOTLB_FORCE) |
| max_segment = 1; |
| else |
| max_segment = rounddown(val, PAGE_SIZE); |
| } |
| |
| /* default to 64MB */ |
| #define IO_TLB_DEFAULT_SIZE (64UL<<20) |
| unsigned long swiotlb_size_or_default(void) |
| { |
| unsigned long size; |
| |
| size = io_tlb_nslabs << IO_TLB_SHIFT; |
| |
| return size ? size : (IO_TLB_DEFAULT_SIZE); |
| } |
| |
| static bool no_iotlb_memory; |
| |
| void swiotlb_print_info(void) |
| { |
| unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT; |
| |
| if (no_iotlb_memory) { |
| pr_warn("No low mem\n"); |
| return; |
| } |
| |
| pr_info("mapped [mem %#010llx-%#010llx] (%luMB)\n", |
| (unsigned long long)io_tlb_start, |
| (unsigned long long)io_tlb_end, |
| bytes >> 20); |
| } |
| |
| /* |
| * 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) |
| { |
| void *vaddr; |
| unsigned long bytes; |
| |
| if (no_iotlb_memory || late_alloc) |
| return; |
| |
| vaddr = phys_to_virt(io_tlb_start); |
| bytes = PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT); |
| set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT); |
| memset(vaddr, 0, bytes); |
| } |
| |
| int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) |
| { |
| unsigned long i, bytes; |
| size_t alloc_size; |
| |
| bytes = nslabs << IO_TLB_SHIFT; |
| |
| io_tlb_nslabs = nslabs; |
| io_tlb_start = __pa(tlb); |
| io_tlb_end = io_tlb_start + bytes; |
| |
| /* |
| * Allocate and initialize the free list array. This array is used |
| * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE |
| * between io_tlb_start and io_tlb_end. |
| */ |
| alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(int)); |
| io_tlb_list = memblock_alloc(alloc_size, PAGE_SIZE); |
| if (!io_tlb_list) |
| panic("%s: Failed to allocate %zu bytes align=0x%lx\n", |
| __func__, alloc_size, PAGE_SIZE); |
| |
| alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)); |
| io_tlb_orig_addr = memblock_alloc(alloc_size, PAGE_SIZE); |
| if (!io_tlb_orig_addr) |
| panic("%s: Failed to allocate %zu bytes align=0x%lx\n", |
| __func__, alloc_size, PAGE_SIZE); |
| |
| for (i = 0; i < io_tlb_nslabs; i++) { |
| io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE); |
| io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; |
| } |
| io_tlb_index = 0; |
| |
| if (verbose) |
| swiotlb_print_info(); |
| |
| swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT); |
| return 0; |
| } |
| |
| /* |
| * 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(int verbose) |
| { |
| size_t default_size = IO_TLB_DEFAULT_SIZE; |
| unsigned char *vstart; |
| unsigned long bytes; |
| |
| if (!io_tlb_nslabs) { |
| io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); |
| io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); |
| } |
| |
| bytes = io_tlb_nslabs << IO_TLB_SHIFT; |
| |
| /* Get IO TLB memory from the low pages */ |
| vstart = memblock_alloc_low(PAGE_ALIGN(bytes), PAGE_SIZE); |
| if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose)) |
| return; |
| |
| if (io_tlb_start) |
| memblock_free_early(io_tlb_start, |
| PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT)); |
| pr_warn("Cannot allocate buffer"); |
| no_iotlb_memory = true; |
| } |
| |
| /* |
| * 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_late_init_with_default_size(size_t default_size) |
| { |
| unsigned long bytes, req_nslabs = io_tlb_nslabs; |
| unsigned char *vstart = NULL; |
| unsigned int order; |
| int rc = 0; |
| |
| if (!io_tlb_nslabs) { |
| io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); |
| io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); |
| } |
| |
| /* |
| * Get IO TLB memory from the low pages |
| */ |
| order = get_order(io_tlb_nslabs << IO_TLB_SHIFT); |
| io_tlb_nslabs = SLABS_PER_PAGE << order; |
| bytes = io_tlb_nslabs << IO_TLB_SHIFT; |
| |
| while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) { |
| vstart = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, |
| order); |
| if (vstart) |
| break; |
| order--; |
| } |
| |
| if (!vstart) { |
| io_tlb_nslabs = req_nslabs; |
| return -ENOMEM; |
| } |
| if (order != get_order(bytes)) { |
| pr_warn("only able to allocate %ld MB\n", |
| (PAGE_SIZE << order) >> 20); |
| io_tlb_nslabs = SLABS_PER_PAGE << order; |
| } |
| rc = swiotlb_late_init_with_tbl(vstart, io_tlb_nslabs); |
| if (rc) |
| free_pages((unsigned long)vstart, order); |
| |
| return rc; |
| } |
| |
| int |
| swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) |
| { |
| unsigned long i, bytes; |
| |
| bytes = nslabs << IO_TLB_SHIFT; |
| |
| io_tlb_nslabs = nslabs; |
| io_tlb_start = virt_to_phys(tlb); |
| io_tlb_end = io_tlb_start + bytes; |
| |
| set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT); |
| memset(tlb, 0, bytes); |
| |
| /* |
| * Allocate and initialize the free list array. This array is used |
| * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE |
| * between io_tlb_start and io_tlb_end. |
| */ |
| io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL, |
| get_order(io_tlb_nslabs * sizeof(int))); |
| if (!io_tlb_list) |
| goto cleanup3; |
| |
| io_tlb_orig_addr = (phys_addr_t *) |
| __get_free_pages(GFP_KERNEL, |
| get_order(io_tlb_nslabs * |
| sizeof(phys_addr_t))); |
| if (!io_tlb_orig_addr) |
| goto cleanup4; |
| |
| for (i = 0; i < io_tlb_nslabs; i++) { |
| io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE); |
| io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; |
| } |
| io_tlb_index = 0; |
| |
| swiotlb_print_info(); |
| |
| late_alloc = 1; |
| |
| swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT); |
| |
| return 0; |
| |
| cleanup4: |
| free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs * |
| sizeof(int))); |
| io_tlb_list = NULL; |
| cleanup3: |
| io_tlb_end = 0; |
| io_tlb_start = 0; |
| io_tlb_nslabs = 0; |
| max_segment = 0; |
| return -ENOMEM; |
| } |
| |
| void __init swiotlb_exit(void) |
| { |
| if (!io_tlb_orig_addr) |
| return; |
| |
| if (late_alloc) { |
| free_pages((unsigned long)io_tlb_orig_addr, |
| get_order(io_tlb_nslabs * sizeof(phys_addr_t))); |
| free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs * |
| sizeof(int))); |
| free_pages((unsigned long)phys_to_virt(io_tlb_start), |
| get_order(io_tlb_nslabs << IO_TLB_SHIFT)); |
| } else { |
| memblock_free_late(__pa(io_tlb_orig_addr), |
| PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t))); |
| memblock_free_late(__pa(io_tlb_list), |
| PAGE_ALIGN(io_tlb_nslabs * sizeof(int))); |
| memblock_free_late(io_tlb_start, |
| PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT)); |
| } |
| io_tlb_start = 0; |
| io_tlb_end = 0; |
| io_tlb_nslabs = 0; |
| max_segment = 0; |
| } |
| |
| /* |
| * Bounce: copy the swiotlb buffer from or back to the original dma location |
| */ |
| static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, |
| size_t size, enum dma_data_direction dir) |
| { |
| unsigned long pfn = PFN_DOWN(orig_addr); |
| unsigned char *vaddr = phys_to_virt(tlb_addr); |
| |
| if (PageHighMem(pfn_to_page(pfn))) { |
| /* The buffer does not have a mapping. Map it in and copy */ |
| unsigned int offset = orig_addr & ~PAGE_MASK; |
| char *buffer; |
| unsigned int sz = 0; |
| unsigned long flags; |
| |
| while (size) { |
| sz = min_t(size_t, PAGE_SIZE - offset, size); |
| |
| local_irq_save(flags); |
| buffer = kmap_atomic(pfn_to_page(pfn)); |
| if (dir == DMA_TO_DEVICE) |
| memcpy(vaddr, buffer + offset, sz); |
| else |
| memcpy(buffer + offset, vaddr, sz); |
| kunmap_atomic(buffer); |
| 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); |
| } |
| } |
| |
| phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, |
| dma_addr_t tbl_dma_addr, |
| phys_addr_t orig_addr, size_t size, |
| enum dma_data_direction dir, |
| unsigned long attrs) |
| { |
| unsigned long flags; |
| phys_addr_t tlb_addr; |
| unsigned int nslots, stride, index, wrap; |
| int i; |
| unsigned long mask; |
| unsigned long offset_slots; |
| unsigned long max_slots; |
| |
| if (no_iotlb_memory) |
| panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); |
| |
| if (mem_encrypt_active()) |
| pr_warn_once("%s is active and system is using DMA bounce buffers\n", |
| sme_active() ? "SME" : "SEV"); |
| |
| mask = dma_get_seg_boundary(hwdev); |
| |
| tbl_dma_addr &= mask; |
| |
| offset_slots = ALIGN(tbl_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; |
| |
| /* |
| * Carefully handle integer overflow which can occur when mask == ~0UL. |
| */ |
| max_slots = mask + 1 |
| ? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT |
| : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT); |
| |
| /* |
| * For mappings greater than or equal to a page, we limit the stride |
| * (and hence alignment) to a page size. |
| */ |
| nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; |
| if (size >= PAGE_SIZE) |
| stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT)); |
| else |
| stride = 1; |
| |
| BUG_ON(!nslots); |
| |
| /* |
| * Find suitable number of IO TLB entries size that will fit this |
| * request and allocate a buffer from that IO TLB pool. |
| */ |
| spin_lock_irqsave(&io_tlb_lock, flags); |
| |
| if (unlikely(nslots > io_tlb_nslabs - io_tlb_used)) |
| goto not_found; |
| |
| index = ALIGN(io_tlb_index, stride); |
| if (index >= io_tlb_nslabs) |
| index = 0; |
| wrap = index; |
| |
| do { |
| while (iommu_is_span_boundary(index, nslots, offset_slots, |
| max_slots)) { |
| index += stride; |
| if (index >= io_tlb_nslabs) |
| index = 0; |
| if (index == wrap) |
| goto not_found; |
| } |
| |
| /* |
| * 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 (io_tlb_list[index] >= nslots) { |
| int count = 0; |
| |
| for (i = index; i < (int) (index + nslots); i++) |
| io_tlb_list[i] = 0; |
| for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--) |
| io_tlb_list[i] = ++count; |
| tlb_addr = io_tlb_start + (index << IO_TLB_SHIFT); |
| |
| /* |
| * Update the indices to avoid searching in the next |
| * round. |
| */ |
| io_tlb_index = ((index + nslots) < io_tlb_nslabs |
| ? (index + nslots) : 0); |
| |
| goto found; |
| } |
| index += stride; |
| if (index >= io_tlb_nslabs) |
| index = 0; |
| } while (index != wrap); |
| |
| not_found: |
| spin_unlock_irqrestore(&io_tlb_lock, flags); |
| if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) |
| dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size); |
| return DMA_MAPPING_ERROR; |
| found: |
| io_tlb_used += nslots; |
| spin_unlock_irqrestore(&io_tlb_lock, flags); |
| |
| /* |
| * 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 < nslots; i++) |
| io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT); |
| if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && |
| (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) |
| swiotlb_bounce(orig_addr, tlb_addr, size, DMA_TO_DEVICE); |
| |
| return tlb_addr; |
| } |
| |
| /* |
| * tlb_addr is the physical address of the bounce buffer to unmap. |
| */ |
| void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, |
| size_t size, enum dma_data_direction dir, |
| unsigned long attrs) |
| { |
| unsigned long flags; |
| int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; |
| int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT; |
| phys_addr_t orig_addr = io_tlb_orig_addr[index]; |
| |
| /* |
| * First, sync the memory before unmapping the entry |
| */ |
| if (orig_addr != INVALID_PHYS_ADDR && |
| !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && |
| ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))) |
| swiotlb_bounce(orig_addr, tlb_addr, size, DMA_FROM_DEVICE); |
| |
| /* |
| * 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. |
| */ |
| spin_lock_irqsave(&io_tlb_lock, flags); |
| { |
| count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ? |
| io_tlb_list[index + nslots] : 0); |
| /* |
| * Step 1: return the slots to the free list, merging the |
| * slots with superceeding slots |
| */ |
| for (i = index + nslots - 1; i >= index; i--) { |
| io_tlb_list[i] = ++count; |
| io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; |
| } |
| /* |
| * Step 2: merge the returned slots with the preceding slots, |
| * if available (non zero) |
| */ |
| for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--) |
| io_tlb_list[i] = ++count; |
| |
| io_tlb_used -= nslots; |
| } |
| spin_unlock_irqrestore(&io_tlb_lock, flags); |
| } |
| |
| void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, |
| size_t size, enum dma_data_direction dir, |
| enum dma_sync_target target) |
| { |
| int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT; |
| phys_addr_t orig_addr = io_tlb_orig_addr[index]; |
| |
| if (orig_addr == INVALID_PHYS_ADDR) |
| return; |
| orig_addr += (unsigned long)tlb_addr & ((1 << IO_TLB_SHIFT) - 1); |
| |
| switch (target) { |
| case SYNC_FOR_CPU: |
| if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) |
| swiotlb_bounce(orig_addr, tlb_addr, |
| size, DMA_FROM_DEVICE); |
| else |
| BUG_ON(dir != DMA_TO_DEVICE); |
| break; |
| case SYNC_FOR_DEVICE: |
| if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) |
| swiotlb_bounce(orig_addr, tlb_addr, |
| size, DMA_TO_DEVICE); |
| else |
| BUG_ON(dir != DMA_FROM_DEVICE); |
| break; |
| default: |
| BUG(); |
| } |
| } |
| |
| /* |
| * Create a swiotlb mapping for the buffer at @phys, and in case of DMAing |
| * to the device copy the data into it as well. |
| */ |
| bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr, |
| size_t size, enum dma_data_direction dir, unsigned long attrs) |
| { |
| trace_swiotlb_bounced(dev, *dma_addr, size, swiotlb_force); |
| |
| if (unlikely(swiotlb_force == SWIOTLB_NO_FORCE)) { |
| dev_warn_ratelimited(dev, |
| "Cannot do DMA to address %pa\n", phys); |
| return false; |
| } |
| |
| /* Oh well, have to allocate and map a bounce buffer. */ |
| *phys = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start), |
| *phys, size, dir, attrs); |
| if (*phys == DMA_MAPPING_ERROR) |
| return false; |
| |
| /* Ensure that the address returned is DMA'ble */ |
| *dma_addr = __phys_to_dma(dev, *phys); |
| if (unlikely(!dma_capable(dev, *dma_addr, size))) { |
| swiotlb_tbl_unmap_single(dev, *phys, size, dir, |
| attrs | DMA_ATTR_SKIP_CPU_SYNC); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| size_t swiotlb_max_mapping_size(struct device *dev) |
| { |
| return ((size_t)1 << IO_TLB_SHIFT) * IO_TLB_SEGSIZE; |
| } |
| |
| bool is_swiotlb_active(void) |
| { |
| /* |
| * When SWIOTLB is initialized, even if io_tlb_start points to physical |
| * address zero, io_tlb_end surely doesn't. |
| */ |
| return io_tlb_end != 0; |
| } |
| |
| #ifdef CONFIG_DEBUG_FS |
| |
| static int __init swiotlb_create_debugfs(void) |
| { |
| struct dentry *d_swiotlb_usage; |
| struct dentry *ent; |
| |
| d_swiotlb_usage = debugfs_create_dir("swiotlb", NULL); |
| |
| if (!d_swiotlb_usage) |
| return -ENOMEM; |
| |
| ent = debugfs_create_ulong("io_tlb_nslabs", 0400, |
| d_swiotlb_usage, &io_tlb_nslabs); |
| if (!ent) |
| goto fail; |
| |
| ent = debugfs_create_ulong("io_tlb_used", 0400, |
| d_swiotlb_usage, &io_tlb_used); |
| if (!ent) |
| goto fail; |
| |
| return 0; |
| |
| fail: |
| debugfs_remove_recursive(d_swiotlb_usage); |
| return -ENOMEM; |
| } |
| |
| late_initcall(swiotlb_create_debugfs); |
| |
| #endif |