| /* |
| * 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 |
| */ |
| |
| #include <linux/cache.h> |
| #include <linux/dma-mapping.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 <asm/io.h> |
| #include <asm/dma.h> |
| |
| #include <linux/init.h> |
| #include <linux/bootmem.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) |
| |
| int 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. |
| */ |
| static 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; |
| |
| /* |
| * When the IOMMU overflows we return a fallback buffer. This sets the size. |
| */ |
| static unsigned long io_tlb_overflow = 32*1024; |
| |
| static phys_addr_t io_tlb_overflow_buffer; |
| |
| /* |
| * 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; |
| |
| /* |
| * 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 = 1; |
| |
| return 0; |
| } |
| early_param("swiotlb", setup_io_tlb_npages); |
| /* make io_tlb_overflow tunable too? */ |
| |
| unsigned long swiotlb_nr_tbl(void) |
| { |
| return io_tlb_nslabs; |
| } |
| EXPORT_SYMBOL_GPL(swiotlb_nr_tbl); |
| |
| /* 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); |
| } |
| |
| /* Note that this doesn't work with highmem page */ |
| static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev, |
| volatile void *address) |
| { |
| return phys_to_dma(hwdev, virt_to_phys(address)); |
| } |
| |
| static bool no_iotlb_memory; |
| |
| void swiotlb_print_info(void) |
| { |
| unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT; |
| unsigned char *vstart, *vend; |
| |
| if (no_iotlb_memory) { |
| pr_warn("software IO TLB: No low mem\n"); |
| return; |
| } |
| |
| vstart = phys_to_virt(io_tlb_start); |
| vend = phys_to_virt(io_tlb_end); |
| |
| printk(KERN_INFO "software IO TLB [mem %#010llx-%#010llx] (%luMB) mapped at [%p-%p]\n", |
| (unsigned long long)io_tlb_start, |
| (unsigned long long)io_tlb_end, |
| bytes >> 20, vstart, vend - 1); |
| } |
| |
| int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) |
| { |
| void *v_overflow_buffer; |
| unsigned long i, bytes; |
| |
| bytes = nslabs << IO_TLB_SHIFT; |
| |
| io_tlb_nslabs = nslabs; |
| io_tlb_start = __pa(tlb); |
| io_tlb_end = io_tlb_start + bytes; |
| |
| /* |
| * Get the overflow emergency buffer |
| */ |
| v_overflow_buffer = memblock_virt_alloc_low_nopanic( |
| PAGE_ALIGN(io_tlb_overflow), |
| PAGE_SIZE); |
| if (!v_overflow_buffer) |
| return -ENOMEM; |
| |
| io_tlb_overflow_buffer = __pa(v_overflow_buffer); |
| |
| /* |
| * 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 = memblock_virt_alloc( |
| PAGE_ALIGN(io_tlb_nslabs * sizeof(int)), |
| PAGE_SIZE); |
| io_tlb_orig_addr = memblock_virt_alloc( |
| PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)), |
| 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(); |
| |
| 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_virt_alloc_low_nopanic(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 SWIOTLB 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)) { |
| printk(KERN_WARNING "Warning: only able to allocate %ld MB " |
| "for software IO TLB\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; |
| unsigned char *v_overflow_buffer; |
| |
| bytes = nslabs << IO_TLB_SHIFT; |
| |
| io_tlb_nslabs = nslabs; |
| io_tlb_start = virt_to_phys(tlb); |
| io_tlb_end = io_tlb_start + bytes; |
| |
| memset(tlb, 0, bytes); |
| |
| /* |
| * Get the overflow emergency buffer |
| */ |
| v_overflow_buffer = (void *)__get_free_pages(GFP_DMA, |
| get_order(io_tlb_overflow)); |
| if (!v_overflow_buffer) |
| goto cleanup2; |
| |
| io_tlb_overflow_buffer = virt_to_phys(v_overflow_buffer); |
| |
| /* |
| * 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; |
| |
| return 0; |
| |
| cleanup4: |
| free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs * |
| sizeof(int))); |
| io_tlb_list = NULL; |
| cleanup3: |
| free_pages((unsigned long)v_overflow_buffer, |
| get_order(io_tlb_overflow)); |
| io_tlb_overflow_buffer = 0; |
| cleanup2: |
| io_tlb_end = 0; |
| io_tlb_start = 0; |
| io_tlb_nslabs = 0; |
| return -ENOMEM; |
| } |
| |
| void __init swiotlb_free(void) |
| { |
| if (!io_tlb_orig_addr) |
| return; |
| |
| if (late_alloc) { |
| free_pages((unsigned long)phys_to_virt(io_tlb_overflow_buffer), |
| get_order(io_tlb_overflow)); |
| 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(io_tlb_overflow_buffer, |
| PAGE_ALIGN(io_tlb_overflow)); |
| 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_nslabs = 0; |
| } |
| |
| int is_swiotlb_buffer(phys_addr_t paddr) |
| { |
| return paddr >= io_tlb_start && paddr < io_tlb_end; |
| } |
| |
| /* |
| * Bounce: copy the swiotlb buffer 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 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"); |
| |
| 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); |
| 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 (printk_ratelimit()) |
| dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size); |
| return SWIOTLB_MAP_ERROR; |
| found: |
| 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 (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) |
| swiotlb_bounce(orig_addr, tlb_addr, size, DMA_TO_DEVICE); |
| |
| return tlb_addr; |
| } |
| EXPORT_SYMBOL_GPL(swiotlb_tbl_map_single); |
| |
| /* |
| * Allocates bounce buffer and returns its kernel virtual address. |
| */ |
| |
| static phys_addr_t |
| map_single(struct device *hwdev, phys_addr_t phys, size_t size, |
| enum dma_data_direction dir) |
| { |
| dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start); |
| |
| return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir); |
| } |
| |
| /* |
| * dma_addr is the kernel virtual 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 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 && |
| ((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; |
| } |
| spin_unlock_irqrestore(&io_tlb_lock, flags); |
| } |
| EXPORT_SYMBOL_GPL(swiotlb_tbl_unmap_single); |
| |
| void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, |
| size_t size, enum dma_data_direction dir, |
| 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(); |
| } |
| } |
| EXPORT_SYMBOL_GPL(swiotlb_tbl_sync_single); |
| |
| void * |
| swiotlb_alloc_coherent(struct device *hwdev, size_t size, |
| dma_addr_t *dma_handle, gfp_t flags) |
| { |
| dma_addr_t dev_addr; |
| void *ret; |
| int order = get_order(size); |
| u64 dma_mask = DMA_BIT_MASK(32); |
| |
| if (hwdev && hwdev->coherent_dma_mask) |
| dma_mask = hwdev->coherent_dma_mask; |
| |
| ret = (void *)__get_free_pages(flags, order); |
| if (ret) { |
| dev_addr = swiotlb_virt_to_bus(hwdev, ret); |
| if (dev_addr + size - 1 > dma_mask) { |
| /* |
| * The allocated memory isn't reachable by the device. |
| */ |
| free_pages((unsigned long) ret, order); |
| ret = NULL; |
| } |
| } |
| if (!ret) { |
| /* |
| * We are either out of memory or the device can't DMA to |
| * GFP_DMA memory; fall back on map_single(), which |
| * will grab memory from the lowest available address range. |
| */ |
| phys_addr_t paddr = map_single(hwdev, 0, size, DMA_FROM_DEVICE); |
| if (paddr == SWIOTLB_MAP_ERROR) |
| goto err_warn; |
| |
| ret = phys_to_virt(paddr); |
| dev_addr = phys_to_dma(hwdev, paddr); |
| |
| /* Confirm address can be DMA'd by device */ |
| if (dev_addr + size - 1 > dma_mask) { |
| printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n", |
| (unsigned long long)dma_mask, |
| (unsigned long long)dev_addr); |
| |
| /* DMA_TO_DEVICE to avoid memcpy in unmap_single */ |
| swiotlb_tbl_unmap_single(hwdev, paddr, |
| size, DMA_TO_DEVICE); |
| goto err_warn; |
| } |
| } |
| |
| *dma_handle = dev_addr; |
| memset(ret, 0, size); |
| |
| return ret; |
| |
| err_warn: |
| pr_warn("swiotlb: coherent allocation failed for device %s size=%zu\n", |
| dev_name(hwdev), size); |
| dump_stack(); |
| |
| return NULL; |
| } |
| EXPORT_SYMBOL(swiotlb_alloc_coherent); |
| |
| void |
| swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, |
| dma_addr_t dev_addr) |
| { |
| phys_addr_t paddr = dma_to_phys(hwdev, dev_addr); |
| |
| WARN_ON(irqs_disabled()); |
| if (!is_swiotlb_buffer(paddr)) |
| free_pages((unsigned long)vaddr, get_order(size)); |
| else |
| /* DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single */ |
| swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE); |
| } |
| EXPORT_SYMBOL(swiotlb_free_coherent); |
| |
| static void |
| swiotlb_full(struct device *dev, size_t size, enum dma_data_direction dir, |
| int do_panic) |
| { |
| /* |
| * Ran out of IOMMU space for this operation. This is very bad. |
| * Unfortunately the drivers cannot handle this operation properly. |
| * unless they check for dma_mapping_error (most don't) |
| * When the mapping is small enough return a static buffer to limit |
| * the damage, or panic when the transfer is too big. |
| */ |
| printk(KERN_ERR "DMA: Out of SW-IOMMU space for %zu bytes at " |
| "device %s\n", size, dev ? dev_name(dev) : "?"); |
| |
| if (size <= io_tlb_overflow || !do_panic) |
| return; |
| |
| if (dir == DMA_BIDIRECTIONAL) |
| panic("DMA: Random memory could be DMA accessed\n"); |
| if (dir == DMA_FROM_DEVICE) |
| panic("DMA: Random memory could be DMA written\n"); |
| if (dir == DMA_TO_DEVICE) |
| panic("DMA: Random memory could be DMA read\n"); |
| } |
| |
| /* |
| * Map a single buffer of the indicated size for DMA in streaming mode. The |
| * physical address to use is returned. |
| * |
| * Once the device is given the dma address, the device owns this memory until |
| * either swiotlb_unmap_page or swiotlb_dma_sync_single is performed. |
| */ |
| dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, |
| unsigned long offset, size_t size, |
| enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| phys_addr_t map, phys = page_to_phys(page) + offset; |
| dma_addr_t dev_addr = phys_to_dma(dev, phys); |
| |
| BUG_ON(dir == DMA_NONE); |
| /* |
| * If the address happens to be in the device's DMA window, |
| * we can safely return the device addr and not worry about bounce |
| * buffering it. |
| */ |
| if (dma_capable(dev, dev_addr, size) && !swiotlb_force) |
| return dev_addr; |
| |
| trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force); |
| |
| /* Oh well, have to allocate and map a bounce buffer. */ |
| map = map_single(dev, phys, size, dir); |
| if (map == SWIOTLB_MAP_ERROR) { |
| swiotlb_full(dev, size, dir, 1); |
| return phys_to_dma(dev, io_tlb_overflow_buffer); |
| } |
| |
| dev_addr = phys_to_dma(dev, map); |
| |
| /* Ensure that the address returned is DMA'ble */ |
| if (!dma_capable(dev, dev_addr, size)) { |
| swiotlb_tbl_unmap_single(dev, map, size, dir); |
| return phys_to_dma(dev, io_tlb_overflow_buffer); |
| } |
| |
| return dev_addr; |
| } |
| EXPORT_SYMBOL_GPL(swiotlb_map_page); |
| |
| /* |
| * Unmap a single streaming mode DMA translation. The dma_addr and size must |
| * match what was provided for in a previous swiotlb_map_page call. All |
| * other usages are undefined. |
| * |
| * After this call, reads by the cpu to the buffer are guaranteed to see |
| * whatever the device wrote there. |
| */ |
| static void unmap_single(struct device *hwdev, dma_addr_t dev_addr, |
| size_t size, enum dma_data_direction dir) |
| { |
| phys_addr_t paddr = dma_to_phys(hwdev, dev_addr); |
| |
| BUG_ON(dir == DMA_NONE); |
| |
| if (is_swiotlb_buffer(paddr)) { |
| swiotlb_tbl_unmap_single(hwdev, paddr, size, dir); |
| return; |
| } |
| |
| if (dir != DMA_FROM_DEVICE) |
| return; |
| |
| /* |
| * phys_to_virt doesn't work with hihgmem page but we could |
| * call dma_mark_clean() with hihgmem page here. However, we |
| * are fine since dma_mark_clean() is null on POWERPC. We can |
| * make dma_mark_clean() take a physical address if necessary. |
| */ |
| dma_mark_clean(phys_to_virt(paddr), size); |
| } |
| |
| void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, |
| size_t size, enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| unmap_single(hwdev, dev_addr, size, dir); |
| } |
| EXPORT_SYMBOL_GPL(swiotlb_unmap_page); |
| |
| /* |
| * Make physical memory consistent for a single streaming mode DMA translation |
| * after a transfer. |
| * |
| * If you perform a swiotlb_map_page() but wish to interrogate the buffer |
| * using the cpu, yet do not wish to teardown the dma mapping, you must |
| * call this function before doing so. At the next point you give the dma |
| * address back to the card, you must first perform a |
| * swiotlb_dma_sync_for_device, and then the device again owns the buffer |
| */ |
| static void |
| swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, |
| size_t size, enum dma_data_direction dir, |
| enum dma_sync_target target) |
| { |
| phys_addr_t paddr = dma_to_phys(hwdev, dev_addr); |
| |
| BUG_ON(dir == DMA_NONE); |
| |
| if (is_swiotlb_buffer(paddr)) { |
| swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target); |
| return; |
| } |
| |
| if (dir != DMA_FROM_DEVICE) |
| return; |
| |
| dma_mark_clean(phys_to_virt(paddr), size); |
| } |
| |
| void |
| swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, |
| size_t size, enum dma_data_direction dir) |
| { |
| swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU); |
| } |
| EXPORT_SYMBOL(swiotlb_sync_single_for_cpu); |
| |
| void |
| swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, |
| size_t size, enum dma_data_direction dir) |
| { |
| swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE); |
| } |
| EXPORT_SYMBOL(swiotlb_sync_single_for_device); |
| |
| /* |
| * Map a set of buffers described by scatterlist in streaming mode for DMA. |
| * This is the scatter-gather version of the above swiotlb_map_page |
| * interface. Here the scatter gather list elements are each tagged with the |
| * appropriate dma address and length. They are obtained via |
| * sg_dma_{address,length}(SG). |
| * |
| * NOTE: An implementation may be able to use a smaller number of |
| * DMA address/length pairs than there are SG table elements. |
| * (for example via virtual mapping capabilities) |
| * The routine returns the number of addr/length pairs actually |
| * used, at most nents. |
| * |
| * Device ownership issues as mentioned above for swiotlb_map_page are the |
| * same here. |
| */ |
| int |
| swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir, struct dma_attrs *attrs) |
| { |
| struct scatterlist *sg; |
| int i; |
| |
| BUG_ON(dir == DMA_NONE); |
| |
| for_each_sg(sgl, sg, nelems, i) { |
| phys_addr_t paddr = sg_phys(sg); |
| dma_addr_t dev_addr = phys_to_dma(hwdev, paddr); |
| |
| if (swiotlb_force || |
| !dma_capable(hwdev, dev_addr, sg->length)) { |
| phys_addr_t map = map_single(hwdev, sg_phys(sg), |
| sg->length, dir); |
| if (map == SWIOTLB_MAP_ERROR) { |
| /* Don't panic here, we expect map_sg users |
| to do proper error handling. */ |
| swiotlb_full(hwdev, sg->length, dir, 0); |
| swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir, |
| attrs); |
| sg_dma_len(sgl) = 0; |
| return 0; |
| } |
| sg->dma_address = phys_to_dma(hwdev, map); |
| } else |
| sg->dma_address = dev_addr; |
| sg_dma_len(sg) = sg->length; |
| } |
| return nelems; |
| } |
| EXPORT_SYMBOL(swiotlb_map_sg_attrs); |
| |
| int |
| swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir) |
| { |
| return swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL); |
| } |
| EXPORT_SYMBOL(swiotlb_map_sg); |
| |
| /* |
| * Unmap a set of streaming mode DMA translations. Again, cpu read rules |
| * concerning calls here are the same as for swiotlb_unmap_page() above. |
| */ |
| void |
| swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, |
| int nelems, enum dma_data_direction dir, struct dma_attrs *attrs) |
| { |
| struct scatterlist *sg; |
| int i; |
| |
| BUG_ON(dir == DMA_NONE); |
| |
| for_each_sg(sgl, sg, nelems, i) |
| unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir); |
| |
| } |
| EXPORT_SYMBOL(swiotlb_unmap_sg_attrs); |
| |
| void |
| swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir) |
| { |
| return swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL); |
| } |
| EXPORT_SYMBOL(swiotlb_unmap_sg); |
| |
| /* |
| * Make physical memory consistent for a set of streaming mode DMA translations |
| * after a transfer. |
| * |
| * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules |
| * and usage. |
| */ |
| static void |
| swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl, |
| int nelems, enum dma_data_direction dir, |
| enum dma_sync_target target) |
| { |
| struct scatterlist *sg; |
| int i; |
| |
| for_each_sg(sgl, sg, nelems, i) |
| swiotlb_sync_single(hwdev, sg->dma_address, |
| sg_dma_len(sg), dir, target); |
| } |
| |
| void |
| swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, |
| int nelems, enum dma_data_direction dir) |
| { |
| swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU); |
| } |
| EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu); |
| |
| void |
| swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, |
| int nelems, enum dma_data_direction dir) |
| { |
| swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE); |
| } |
| EXPORT_SYMBOL(swiotlb_sync_sg_for_device); |
| |
| int |
| swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) |
| { |
| return (dma_addr == phys_to_dma(hwdev, io_tlb_overflow_buffer)); |
| } |
| EXPORT_SYMBOL(swiotlb_dma_mapping_error); |
| |
| /* |
| * Return whether the given device DMA address mask can be supported |
| * properly. For example, if your device can only drive the low 24-bits |
| * during bus mastering, then you would pass 0x00ffffff as the mask to |
| * this function. |
| */ |
| int |
| swiotlb_dma_supported(struct device *hwdev, u64 mask) |
| { |
| return phys_to_dma(hwdev, io_tlb_end - 1) <= mask; |
| } |
| EXPORT_SYMBOL(swiotlb_dma_supported); |