diff options
Diffstat (limited to 'lib/swiotlb.c')
| -rw-r--r-- | lib/swiotlb.c | 1087 |
1 files changed, 0 insertions, 1087 deletions
diff --git a/lib/swiotlb.c b/lib/swiotlb.c deleted file mode 100644 index 04b68d9..0000000 --- a/lib/swiotlb.c +++ /dev/null @@ -1,1087 +0,0 @@ -/* - * 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-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> - -#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) - -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. - */ -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; - -/* - * 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); -/* make io_tlb_overflow tunable too? */ - -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; - 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); -} - -/* - * 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); - - vaddr = phys_to_virt(io_tlb_overflow_buffer); - bytes = PAGE_ALIGN(io_tlb_overflow); - 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) -{ - 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(); - - 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_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; - - set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT); - 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; - - set_memory_decrypted((unsigned long)v_overflow_buffer, - io_tlb_overflow >> PAGE_SHIFT); - memset(v_overflow_buffer, 0, io_tlb_overflow); - 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; - - 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: - 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; - max_segment = 0; - return -ENOMEM; -} - -void __init swiotlb_exit(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; - max_segment = 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 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); - 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 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 (!(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; -} - -/* - * Allocates bounce buffer and returns its physical address. - */ -static phys_addr_t -map_single(struct device *hwdev, phys_addr_t phys, size_t size, - enum dma_data_direction dir, unsigned long attrs) -{ - dma_addr_t start_dma_addr; - - if (swiotlb_force == SWIOTLB_NO_FORCE) { - dev_warn_ratelimited(hwdev, "Cannot do DMA to address %pa\n", - &phys); - return SWIOTLB_MAP_ERROR; - } - - start_dma_addr = __phys_to_dma(hwdev, io_tlb_start); - return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, - dir, attrs); -} - -/* - * 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; - } - 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(); - } -} - -static inline bool dma_coherent_ok(struct device *dev, dma_addr_t addr, - size_t size) -{ - u64 mask = DMA_BIT_MASK(32); - - if (dev && dev->coherent_dma_mask) - mask = dev->coherent_dma_mask; - return addr + size - 1 <= mask; -} - -static void * -swiotlb_alloc_buffer(struct device *dev, size_t size, dma_addr_t *dma_handle, - unsigned long attrs) -{ - phys_addr_t phys_addr; - - if (swiotlb_force == SWIOTLB_NO_FORCE) - goto out_warn; - - phys_addr = swiotlb_tbl_map_single(dev, - __phys_to_dma(dev, io_tlb_start), - 0, size, DMA_FROM_DEVICE, attrs); - if (phys_addr == SWIOTLB_MAP_ERROR) - goto out_warn; - - *dma_handle = __phys_to_dma(dev, phys_addr); - if (!dma_coherent_ok(dev, *dma_handle, size)) - goto out_unmap; - - memset(phys_to_virt(phys_addr), 0, size); - return phys_to_virt(phys_addr); - -out_unmap: - dev_warn(dev, "hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n", - (unsigned long long)dev->coherent_dma_mask, - (unsigned long long)*dma_handle); - - /* - * DMA_TO_DEVICE to avoid memcpy in unmap_single. - * DMA_ATTR_SKIP_CPU_SYNC is optional. - */ - swiotlb_tbl_unmap_single(dev, phys_addr, size, DMA_TO_DEVICE, - DMA_ATTR_SKIP_CPU_SYNC); -out_warn: - if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) { - dev_warn(dev, - "swiotlb: coherent allocation failed, size=%zu\n", - size); - dump_stack(); - } - return NULL; -} - -static bool swiotlb_free_buffer(struct device *dev, size_t size, - dma_addr_t dma_addr) -{ - phys_addr_t phys_addr = dma_to_phys(dev, dma_addr); - - WARN_ON_ONCE(irqs_disabled()); - - if (!is_swiotlb_buffer(phys_addr)) - return false; - - /* - * DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single. - * DMA_ATTR_SKIP_CPU_SYNC is optional. - */ - swiotlb_tbl_unmap_single(dev, phys_addr, size, DMA_TO_DEVICE, - DMA_ATTR_SKIP_CPU_SYNC); - return true; -} - -static void -swiotlb_full(struct device *dev, size_t size, enum dma_data_direction dir, - int do_panic) -{ - if (swiotlb_force == SWIOTLB_NO_FORCE) - return; - - /* - * 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. - */ - dev_err_ratelimited(dev, "DMA: Out of SW-IOMMU space for %zu bytes\n", - size); - - 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, - unsigned long 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 != 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, attrs); - 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)) - return dev_addr; - - attrs |= DMA_ATTR_SKIP_CPU_SYNC; - swiotlb_tbl_unmap_single(dev, map, size, dir, attrs); - - return __phys_to_dma(dev, io_tlb_overflow_buffer); -} - -/* - * 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, - unsigned long attrs) -{ - 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, attrs); - 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, - unsigned long attrs) -{ - unmap_single(hwdev, dev_addr, size, dir, attrs); -} - -/* - * 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); -} - -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); -} - -/* - * 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, unsigned long 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 == SWIOTLB_FORCE || - !dma_capable(hwdev, dev_addr, sg->length)) { - phys_addr_t map = map_single(hwdev, sg_phys(sg), - sg->length, dir, attrs); - 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); - attrs |= DMA_ATTR_SKIP_CPU_SYNC; - 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; -} - -/* - * 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, - unsigned long 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, - attrs); -} - -/* - * 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); -} - -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); -} - -int -swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) -{ - return (dma_addr == __phys_to_dma(hwdev, io_tlb_overflow_buffer)); -} - -/* - * 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; -} - -void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, - gfp_t gfp, unsigned long attrs) -{ - void *vaddr; - - /* temporary workaround: */ - if (gfp & __GFP_NOWARN) - attrs |= DMA_ATTR_NO_WARN; - - /* - * Don't print a warning when the first allocation attempt fails. - * swiotlb_alloc_coherent() will print a warning when the DMA memory - * allocation ultimately failed. - */ - gfp |= __GFP_NOWARN; - - vaddr = dma_direct_alloc(dev, size, dma_handle, gfp, attrs); - if (!vaddr) - vaddr = swiotlb_alloc_buffer(dev, size, dma_handle, attrs); - return vaddr; -} - -void swiotlb_free(struct device *dev, size_t size, void *vaddr, - dma_addr_t dma_addr, unsigned long attrs) -{ - if (!swiotlb_free_buffer(dev, size, dma_addr)) - dma_direct_free(dev, size, vaddr, dma_addr, attrs); -} - -const struct dma_map_ops swiotlb_dma_ops = { - .mapping_error = swiotlb_dma_mapping_error, - .alloc = swiotlb_alloc, - .free = swiotlb_free, - .sync_single_for_cpu = swiotlb_sync_single_for_cpu, - .sync_single_for_device = swiotlb_sync_single_for_device, - .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, - .sync_sg_for_device = swiotlb_sync_sg_for_device, - .map_sg = swiotlb_map_sg_attrs, - .unmap_sg = swiotlb_unmap_sg_attrs, - .map_page = swiotlb_map_page, - .unmap_page = swiotlb_unmap_page, - .dma_supported = dma_direct_supported, -}; |
