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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Dynamic DMA mapping support.
- *
- * This implementation is a fallback for platforms that do not support
- * I/O TLBs (aka DMA address translation hardware).
- * Copyright (C) 2000 Asit Mallick <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/dma-map-ops.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 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).
- */
- static 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);
- static bool no_iotlb_memory;
- unsigned long swiotlb_nr_tbl(void)
- {
- return unlikely(no_iotlb_memory) ? 0 : io_tlb_nslabs;
- }
- EXPORT_SYMBOL_GPL(swiotlb_nr_tbl);
- unsigned int swiotlb_max_segment(void)
- {
- return unlikely(no_iotlb_memory) ? 0 : 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);
- }
- 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 %pa-%pa] (%luMB)\n", &io_tlb_start, &io_tlb_end,
- bytes >> 20);
- }
- static inline unsigned long io_tlb_offset(unsigned long val)
- {
- return val & (IO_TLB_SEGSIZE - 1);
- }
- static inline unsigned long nr_slots(u64 val)
- {
- return DIV_ROUND_UP(val, IO_TLB_SIZE);
- }
- /*
- * Early SWIOTLB allocation may be too early to allow an architecture to
- * perform the desired operations. This function allows the architecture to
- * call SWIOTLB when the operations are possible. It needs to be called
- * before the SWIOTLB memory is used.
- */
- void __init swiotlb_update_mem_attributes(void)
- {
- 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 - io_tlb_offset(i);
- io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
- }
- io_tlb_index = 0;
- no_iotlb_memory = false;
- 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));
- io_tlb_start = 0;
- }
- 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;
- }
- static void swiotlb_cleanup(void)
- {
- io_tlb_end = 0;
- io_tlb_start = 0;
- io_tlb_nslabs = 0;
- max_segment = 0;
- }
- 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 - io_tlb_offset(i);
- io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
- }
- io_tlb_index = 0;
- no_iotlb_memory = false;
- 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:
- swiotlb_cleanup();
- 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));
- }
- swiotlb_cleanup();
- }
- /*
- * 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);
- }
- }
- #define slot_addr(start, idx) ((start) + ((idx) << IO_TLB_SHIFT))
- /*
- * Return the offset into a iotlb slot required to keep the device happy.
- */
- static unsigned int swiotlb_align_offset(struct device *dev, u64 addr)
- {
- return addr & dma_get_min_align_mask(dev) & (IO_TLB_SIZE - 1);
- }
- /*
- * Carefully handle integer overflow which can occur when boundary_mask == ~0UL.
- */
- 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);
- }
- static unsigned int wrap_index(unsigned int index)
- {
- if (index >= io_tlb_nslabs)
- return 0;
- return index;
- }
- /*
- * Find a suitable number of IO TLB entries size that will fit this request and
- * allocate a buffer from that IO TLB pool.
- */
- static int find_slots(struct device *dev, phys_addr_t orig_addr,
- size_t alloc_size)
- {
- unsigned long boundary_mask = dma_get_seg_boundary(dev);
- dma_addr_t tbl_dma_addr =
- phys_to_dma_unencrypted(dev, io_tlb_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 nslots = nr_slots(alloc_size), stride;
- unsigned int index, wrap, count = 0, i;
- unsigned long flags;
- BUG_ON(!nslots);
- /*
- * 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.
- */
- stride = (iotlb_align_mask >> IO_TLB_SHIFT) + 1;
- if (alloc_size >= PAGE_SIZE)
- stride = max(stride, stride << (PAGE_SHIFT - IO_TLB_SHIFT));
- spin_lock_irqsave(&io_tlb_lock, flags);
- if (unlikely(nslots > io_tlb_nslabs - io_tlb_used))
- goto not_found;
- index = wrap = wrap_index(ALIGN(io_tlb_index, stride));
- do {
- if ((slot_addr(tbl_dma_addr, index) & iotlb_align_mask) !=
- (orig_addr & iotlb_align_mask)) {
- index = wrap_index(index + 1);
- 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(index, nslots,
- nr_slots(tbl_dma_addr),
- max_slots)) {
- if (io_tlb_list[index] >= nslots)
- goto found;
- }
- index = wrap_index(index + stride);
- } while (index != wrap);
- not_found:
- spin_unlock_irqrestore(&io_tlb_lock, flags);
- return -1;
- found:
- for (i = index; i < index + nslots; i++)
- io_tlb_list[i] = 0;
- for (i = index - 1;
- io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&
- io_tlb_list[i]; i--)
- io_tlb_list[i] = ++count;
- /*
- * Update the indices to avoid searching in the next round.
- */
- if (index + nslots < io_tlb_nslabs)
- io_tlb_index = index + nslots;
- else
- io_tlb_index = 0;
- io_tlb_used += nslots;
- spin_unlock_irqrestore(&io_tlb_lock, flags);
- return index;
- }
- phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
- size_t mapping_size, size_t alloc_size,
- enum dma_data_direction dir, unsigned long attrs)
- {
- unsigned int offset = swiotlb_align_offset(dev, orig_addr);
- unsigned int i;
- int index;
- phys_addr_t tlb_addr;
- 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("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;
- }
- index = find_slots(dev, orig_addr, alloc_size + offset);
- 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, io_tlb_nslabs, io_tlb_used);
- return (phys_addr_t)DMA_MAPPING_ERROR;
- }
- /*
- * Save away the mapping from the original address to the DMA address.
- * This is needed when we sync the memory. Then we sync the buffer if
- * needed.
- */
- for (i = 0; i < nr_slots(alloc_size + offset); i++)
- io_tlb_orig_addr[index + i] = slot_addr(orig_addr, i);
- tlb_addr = slot_addr(io_tlb_start, index) + offset;
- if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
- (!(attrs & DMA_ATTR_OVERWRITE) || dir == DMA_TO_DEVICE ||
- dir == DMA_BIDIRECTIONAL))
- swiotlb_bounce(orig_addr, tlb_addr, mapping_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 mapping_size, size_t alloc_size,
- enum dma_data_direction dir, unsigned long attrs)
- {
- unsigned long flags;
- unsigned int offset = swiotlb_align_offset(hwdev, tlb_addr);
- int i, count, nslots = nr_slots(alloc_size + offset);
- int index = (tlb_addr - offset - 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, mapping_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);
- if (index + nslots < ALIGN(index + 1, IO_TLB_SEGSIZE))
- count = io_tlb_list[index + nslots];
- else
- count = 0;
- /*
- * Step 1: return the slots to the free list, merging the slots with
- * superceeding slots
- */
- for (i = index + nslots - 1; i >= index; i--) {
- 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;
- io_tlb_offset(i) != 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 += (tlb_addr & (IO_TLB_SIZE - 1)) -
- swiotlb_align_offset(hwdev, orig_addr);
- 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 @paddr, and in case of DMAing
- * to the device copy the data into it as well.
- */
- dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size,
- enum dma_data_direction dir, unsigned long attrs)
- {
- phys_addr_t swiotlb_addr;
- dma_addr_t dma_addr;
- trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size,
- swiotlb_force);
- swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, 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, size, dir,
- attrs | DMA_ATTR_SKIP_CPU_SYNC);
- dev_WARN_ONCE(dev, 1,
- "swiotlb addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
- &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
- return DMA_MAPPING_ERROR;
- }
- if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
- arch_sync_dma_for_device(swiotlb_addr, size, dir);
- return dma_addr;
- }
- size_t swiotlb_max_mapping_size(struct device *dev)
- {
- return ((size_t)IO_TLB_SIZE) * 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 *root;
- root = debugfs_create_dir("swiotlb", NULL);
- debugfs_create_ulong("io_tlb_nslabs", 0400, root, &io_tlb_nslabs);
- debugfs_create_ulong("io_tlb_used", 0400, root, &io_tlb_used);
- return 0;
- }
- late_initcall(swiotlb_create_debugfs);
- #endif
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