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![Keir Fraser](/assets/img/avatar_default.png)
If the swiotlb maps a multi-slab region, swiotlb_sync_single_range() can be invoked to sync a sub-region which does not include the first slab. Unfortunately io_tlb_orig_addr[] is only initialised for the first slab, and hence the call to sync_single() will read a garbage orig_addr in this case. This patch fixes the issue by initialising all mapped slabs in io_tlb_orig_addr[]. It also correctly adjusts the buffer pointer in sync_single() to handle the case that the given dma_addr is not aligned on a slab boundary. Signed-off-by: Keir Fraser <keir.fraser@cl.cam.ac.uk> Cc: "Luck, Tony" <tony.luck@intel.com> Acked-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
797 lines
22 KiB
C
797 lines
22 KiB
C
/*
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* Dynamic DMA mapping support.
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*
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* This implementation is a fallback for platforms that do not support
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* I/O TLBs (aka DMA address translation hardware).
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* Copyright (C) 2000 Asit Mallick <Asit.K.Mallick@intel.com>
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* Copyright (C) 2000 Goutham Rao <goutham.rao@intel.com>
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* Copyright (C) 2000, 2003 Hewlett-Packard Co
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* David Mosberger-Tang <davidm@hpl.hp.com>
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*
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* 03/05/07 davidm Switch from PCI-DMA to generic device DMA API.
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* 00/12/13 davidm Rename to swiotlb.c and add mark_clean() to avoid
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* unnecessary i-cache flushing.
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* 04/07/.. ak Better overflow handling. Assorted fixes.
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* 05/09/10 linville Add support for syncing ranges, support syncing for
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* DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
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*/
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#include <linux/cache.h>
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#include <linux/dma-mapping.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/ctype.h>
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#include <asm/io.h>
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#include <asm/dma.h>
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#include <asm/scatterlist.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
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#define OFFSET(val,align) ((unsigned long) \
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( (val) & ( (align) - 1)))
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#define SG_ENT_VIRT_ADDRESS(sg) (page_address((sg)->page) + (sg)->offset)
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#define SG_ENT_PHYS_ADDRESS(sg) virt_to_bus(SG_ENT_VIRT_ADDRESS(sg))
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/*
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* Maximum allowable number of contiguous slabs to map,
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* must be a power of 2. What is the appropriate value ?
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* The complexity of {map,unmap}_single is linearly dependent on this value.
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*/
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#define IO_TLB_SEGSIZE 128
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/*
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* log of the size of each IO TLB slab. The number of slabs is command line
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* controllable.
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*/
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#define IO_TLB_SHIFT 11
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#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
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/*
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* Minimum IO TLB size to bother booting with. Systems with mainly
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* 64bit capable cards will only lightly use the swiotlb. If we can't
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* allocate a contiguous 1MB, we're probably in trouble anyway.
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*/
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#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
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/*
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* Enumeration for sync targets
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*/
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enum dma_sync_target {
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SYNC_FOR_CPU = 0,
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SYNC_FOR_DEVICE = 1,
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};
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int swiotlb_force;
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/*
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* Used to do a quick range check in swiotlb_unmap_single and
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* swiotlb_sync_single_*, to see if the memory was in fact allocated by this
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* API.
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*/
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static char *io_tlb_start, *io_tlb_end;
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/*
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* The number of IO TLB blocks (in groups of 64) betweeen io_tlb_start and
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* io_tlb_end. This is command line adjustable via setup_io_tlb_npages.
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*/
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static unsigned long io_tlb_nslabs;
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/*
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* When the IOMMU overflows we return a fallback buffer. This sets the size.
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*/
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static unsigned long io_tlb_overflow = 32*1024;
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void *io_tlb_overflow_buffer;
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/*
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* This is a free list describing the number of free entries available from
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* each index
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*/
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static unsigned int *io_tlb_list;
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static unsigned int io_tlb_index;
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/*
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* We need to save away the original address corresponding to a mapped entry
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* for the sync operations.
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*/
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static unsigned char **io_tlb_orig_addr;
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/*
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* Protect the above data structures in the map and unmap calls
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*/
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static DEFINE_SPINLOCK(io_tlb_lock);
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static int __init
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setup_io_tlb_npages(char *str)
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{
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if (isdigit(*str)) {
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io_tlb_nslabs = simple_strtoul(str, &str, 0);
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/* avoid tail segment of size < IO_TLB_SEGSIZE */
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io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
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}
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if (*str == ',')
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++str;
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if (!strcmp(str, "force"))
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swiotlb_force = 1;
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return 1;
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}
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__setup("swiotlb=", setup_io_tlb_npages);
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/* make io_tlb_overflow tunable too? */
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/*
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* Statically reserve bounce buffer space and initialize bounce buffer data
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* structures for the software IO TLB used to implement the DMA API.
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*/
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void __init
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swiotlb_init_with_default_size(size_t default_size)
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{
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unsigned long i, bytes;
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if (!io_tlb_nslabs) {
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io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
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io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
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}
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bytes = io_tlb_nslabs << IO_TLB_SHIFT;
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/*
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* Get IO TLB memory from the low pages
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*/
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io_tlb_start = alloc_bootmem_low_pages(bytes);
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if (!io_tlb_start)
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panic("Cannot allocate SWIOTLB buffer");
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io_tlb_end = io_tlb_start + bytes;
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/*
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* Allocate and initialize the free list array. This array is used
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* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
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* between io_tlb_start and io_tlb_end.
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*/
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io_tlb_list = alloc_bootmem(io_tlb_nslabs * sizeof(int));
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for (i = 0; i < io_tlb_nslabs; i++)
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io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
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io_tlb_index = 0;
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io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(char *));
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/*
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* Get the overflow emergency buffer
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*/
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io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
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if (!io_tlb_overflow_buffer)
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panic("Cannot allocate SWIOTLB overflow buffer!\n");
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printk(KERN_INFO "Placing software IO TLB between 0x%lx - 0x%lx\n",
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virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));
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}
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void __init
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swiotlb_init(void)
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{
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swiotlb_init_with_default_size(64 * (1<<20)); /* default to 64MB */
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}
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/*
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* Systems with larger DMA zones (those that don't support ISA) can
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* initialize the swiotlb later using the slab allocator if needed.
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* This should be just like above, but with some error catching.
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*/
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int
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swiotlb_late_init_with_default_size(size_t default_size)
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{
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unsigned long i, bytes, req_nslabs = io_tlb_nslabs;
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unsigned int order;
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if (!io_tlb_nslabs) {
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io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
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io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
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}
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/*
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* Get IO TLB memory from the low pages
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*/
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order = get_order(io_tlb_nslabs << IO_TLB_SHIFT);
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io_tlb_nslabs = SLABS_PER_PAGE << order;
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bytes = io_tlb_nslabs << IO_TLB_SHIFT;
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while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
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io_tlb_start = (char *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
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order);
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if (io_tlb_start)
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break;
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order--;
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}
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if (!io_tlb_start)
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goto cleanup1;
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if (order != get_order(bytes)) {
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printk(KERN_WARNING "Warning: only able to allocate %ld MB "
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"for software IO TLB\n", (PAGE_SIZE << order) >> 20);
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io_tlb_nslabs = SLABS_PER_PAGE << order;
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bytes = io_tlb_nslabs << IO_TLB_SHIFT;
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}
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io_tlb_end = io_tlb_start + bytes;
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memset(io_tlb_start, 0, bytes);
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/*
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* Allocate and initialize the free list array. This array is used
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* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
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* between io_tlb_start and io_tlb_end.
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*/
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io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
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get_order(io_tlb_nslabs * sizeof(int)));
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if (!io_tlb_list)
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goto cleanup2;
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for (i = 0; i < io_tlb_nslabs; i++)
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io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
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io_tlb_index = 0;
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io_tlb_orig_addr = (unsigned char **)__get_free_pages(GFP_KERNEL,
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get_order(io_tlb_nslabs * sizeof(char *)));
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if (!io_tlb_orig_addr)
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goto cleanup3;
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memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(char *));
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/*
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* Get the overflow emergency buffer
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*/
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io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
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get_order(io_tlb_overflow));
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if (!io_tlb_overflow_buffer)
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goto cleanup4;
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printk(KERN_INFO "Placing %luMB software IO TLB between 0x%lx - "
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"0x%lx\n", bytes >> 20,
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virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));
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return 0;
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cleanup4:
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free_pages((unsigned long)io_tlb_orig_addr, get_order(io_tlb_nslabs *
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sizeof(char *)));
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io_tlb_orig_addr = NULL;
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cleanup3:
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free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
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sizeof(int)));
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io_tlb_list = NULL;
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cleanup2:
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io_tlb_end = NULL;
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free_pages((unsigned long)io_tlb_start, order);
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io_tlb_start = NULL;
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cleanup1:
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io_tlb_nslabs = req_nslabs;
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return -ENOMEM;
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}
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static int
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address_needs_mapping(struct device *hwdev, dma_addr_t addr)
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{
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dma_addr_t mask = 0xffffffff;
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/* If the device has a mask, use it, otherwise default to 32 bits */
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if (hwdev && hwdev->dma_mask)
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mask = *hwdev->dma_mask;
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return (addr & ~mask) != 0;
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}
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/*
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* Allocates bounce buffer and returns its kernel virtual address.
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*/
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static void *
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map_single(struct device *hwdev, char *buffer, size_t size, int dir)
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{
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unsigned long flags;
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char *dma_addr;
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unsigned int nslots, stride, index, wrap;
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int i;
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/*
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* For mappings greater than a page, we limit the stride (and
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* hence alignment) to a page size.
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*/
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nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
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if (size > PAGE_SIZE)
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stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
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else
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stride = 1;
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BUG_ON(!nslots);
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/*
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* Find suitable number of IO TLB entries size that will fit this
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* request and allocate a buffer from that IO TLB pool.
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*/
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spin_lock_irqsave(&io_tlb_lock, flags);
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{
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wrap = index = ALIGN(io_tlb_index, stride);
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if (index >= io_tlb_nslabs)
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wrap = index = 0;
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do {
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/*
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* If we find a slot that indicates we have 'nslots'
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* number of contiguous buffers, we allocate the
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* buffers from that slot and mark the entries as '0'
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* indicating unavailable.
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*/
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if (io_tlb_list[index] >= nslots) {
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int count = 0;
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for (i = index; i < (int) (index + nslots); i++)
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io_tlb_list[i] = 0;
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for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
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io_tlb_list[i] = ++count;
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dma_addr = io_tlb_start + (index << IO_TLB_SHIFT);
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/*
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* Update the indices to avoid searching in
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* the next round.
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*/
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io_tlb_index = ((index + nslots) < io_tlb_nslabs
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? (index + nslots) : 0);
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goto found;
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}
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index += stride;
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if (index >= io_tlb_nslabs)
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index = 0;
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} while (index != wrap);
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spin_unlock_irqrestore(&io_tlb_lock, flags);
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return NULL;
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}
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found:
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spin_unlock_irqrestore(&io_tlb_lock, flags);
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/*
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* Save away the mapping from the original address to the DMA address.
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* This is needed when we sync the memory. Then we sync the buffer if
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* needed.
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*/
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for (i = 0; i < nslots; i++)
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io_tlb_orig_addr[index+i] = buffer + (i << IO_TLB_SHIFT);
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if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
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memcpy(dma_addr, buffer, size);
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return dma_addr;
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}
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/*
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* dma_addr is the kernel virtual address of the bounce buffer to unmap.
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*/
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static void
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unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
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{
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unsigned long flags;
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int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
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int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
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char *buffer = io_tlb_orig_addr[index];
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/*
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* First, sync the memory before unmapping the entry
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*/
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if (buffer && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
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/*
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* bounce... copy the data back into the original buffer * and
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* delete the bounce buffer.
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*/
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memcpy(buffer, dma_addr, size);
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/*
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* Return the buffer to the free list by setting the corresponding
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* entries to indicate the number of contigous entries available.
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* While returning the entries to the free list, we merge the entries
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* with slots below and above the pool being returned.
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*/
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spin_lock_irqsave(&io_tlb_lock, flags);
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{
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count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
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io_tlb_list[index + nslots] : 0);
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/*
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* Step 1: return the slots to the free list, merging the
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* slots with superceeding slots
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*/
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for (i = index + nslots - 1; i >= index; i--)
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io_tlb_list[i] = ++count;
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/*
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* Step 2: merge the returned slots with the preceding slots,
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* if available (non zero)
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*/
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for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
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io_tlb_list[i] = ++count;
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}
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spin_unlock_irqrestore(&io_tlb_lock, flags);
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}
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static void
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sync_single(struct device *hwdev, char *dma_addr, size_t size,
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int dir, int target)
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{
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int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
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char *buffer = io_tlb_orig_addr[index];
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buffer += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));
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switch (target) {
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case SYNC_FOR_CPU:
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if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
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memcpy(buffer, dma_addr, size);
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else
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BUG_ON(dir != DMA_TO_DEVICE);
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break;
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case SYNC_FOR_DEVICE:
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if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
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memcpy(dma_addr, buffer, size);
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else
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BUG_ON(dir != DMA_FROM_DEVICE);
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break;
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default:
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BUG();
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}
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}
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void *
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swiotlb_alloc_coherent(struct device *hwdev, size_t size,
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dma_addr_t *dma_handle, gfp_t flags)
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{
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dma_addr_t dev_addr;
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void *ret;
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int order = get_order(size);
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/*
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* XXX fix me: the DMA API should pass us an explicit DMA mask
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* instead, or use ZONE_DMA32 (ia64 overloads ZONE_DMA to be a ~32
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* bit range instead of a 16MB one).
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*/
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flags |= GFP_DMA;
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ret = (void *)__get_free_pages(flags, order);
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if (ret && address_needs_mapping(hwdev, virt_to_bus(ret))) {
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/*
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* The allocated memory isn't reachable by the device.
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* Fall back on swiotlb_map_single().
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*/
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free_pages((unsigned long) ret, order);
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ret = NULL;
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}
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if (!ret) {
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/*
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* We are either out of memory or the device can't DMA
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* to GFP_DMA memory; fall back on
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* swiotlb_map_single(), which will grab memory from
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* the lowest available address range.
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*/
|
|
dma_addr_t handle;
|
|
handle = swiotlb_map_single(NULL, NULL, size, DMA_FROM_DEVICE);
|
|
if (swiotlb_dma_mapping_error(handle))
|
|
return NULL;
|
|
|
|
ret = bus_to_virt(handle);
|
|
}
|
|
|
|
memset(ret, 0, size);
|
|
dev_addr = virt_to_bus(ret);
|
|
|
|
/* Confirm address can be DMA'd by device */
|
|
if (address_needs_mapping(hwdev, dev_addr)) {
|
|
printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
|
|
(unsigned long long)*hwdev->dma_mask,
|
|
(unsigned long long)dev_addr);
|
|
panic("swiotlb_alloc_coherent: allocated memory is out of "
|
|
"range for device");
|
|
}
|
|
*dma_handle = dev_addr;
|
|
return ret;
|
|
}
|
|
|
|
void
|
|
swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
|
|
dma_addr_t dma_handle)
|
|
{
|
|
if (!(vaddr >= (void *)io_tlb_start
|
|
&& vaddr < (void *)io_tlb_end))
|
|
free_pages((unsigned long) vaddr, get_order(size));
|
|
else
|
|
/* DMA_TO_DEVICE to avoid memcpy in unmap_single */
|
|
swiotlb_unmap_single (hwdev, dma_handle, size, DMA_TO_DEVICE);
|
|
}
|
|
|
|
static void
|
|
swiotlb_full(struct device *dev, size_t size, int 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->bus_id : "?");
|
|
|
|
if (size > io_tlb_overflow && do_panic) {
|
|
if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
|
|
panic("DMA: Memory would be corrupted\n");
|
|
if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
|
|
panic("DMA: Random memory would be DMAed\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_single or swiotlb_dma_sync_single is performed.
|
|
*/
|
|
dma_addr_t
|
|
swiotlb_map_single(struct device *hwdev, void *ptr, size_t size, int dir)
|
|
{
|
|
dma_addr_t dev_addr = virt_to_bus(ptr);
|
|
void *map;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
/*
|
|
* If the pointer passed in happens to be in the device's DMA window,
|
|
* we can safely return the device addr and not worry about bounce
|
|
* buffering it.
|
|
*/
|
|
if (!address_needs_mapping(hwdev, dev_addr) && !swiotlb_force)
|
|
return dev_addr;
|
|
|
|
/*
|
|
* Oh well, have to allocate and map a bounce buffer.
|
|
*/
|
|
map = map_single(hwdev, ptr, size, dir);
|
|
if (!map) {
|
|
swiotlb_full(hwdev, size, dir, 1);
|
|
map = io_tlb_overflow_buffer;
|
|
}
|
|
|
|
dev_addr = virt_to_bus(map);
|
|
|
|
/*
|
|
* Ensure that the address returned is DMA'ble
|
|
*/
|
|
if (address_needs_mapping(hwdev, dev_addr))
|
|
panic("map_single: bounce buffer is not DMA'ble");
|
|
|
|
return dev_addr;
|
|
}
|
|
|
|
/*
|
|
* Unmap a single streaming mode DMA translation. The dma_addr and size must
|
|
* match what was provided for in a previous swiotlb_map_single 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.
|
|
*/
|
|
void
|
|
swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, size_t size,
|
|
int dir)
|
|
{
|
|
char *dma_addr = bus_to_virt(dev_addr);
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
|
|
unmap_single(hwdev, dma_addr, size, dir);
|
|
else if (dir == DMA_FROM_DEVICE)
|
|
dma_mark_clean(dma_addr, size);
|
|
}
|
|
|
|
/*
|
|
* Make physical memory consistent for a single streaming mode DMA translation
|
|
* after a transfer.
|
|
*
|
|
* If you perform a swiotlb_map_single() 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, int dir, int target)
|
|
{
|
|
char *dma_addr = bus_to_virt(dev_addr);
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
|
|
sync_single(hwdev, dma_addr, size, dir, target);
|
|
else if (dir == DMA_FROM_DEVICE)
|
|
dma_mark_clean(dma_addr, size);
|
|
}
|
|
|
|
void
|
|
swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
|
|
size_t size, int 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, int dir)
|
|
{
|
|
swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
|
|
}
|
|
|
|
/*
|
|
* Same as above, but for a sub-range of the mapping.
|
|
*/
|
|
static void
|
|
swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr,
|
|
unsigned long offset, size_t size,
|
|
int dir, int target)
|
|
{
|
|
char *dma_addr = bus_to_virt(dev_addr) + offset;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
|
|
sync_single(hwdev, dma_addr, size, dir, target);
|
|
else if (dir == DMA_FROM_DEVICE)
|
|
dma_mark_clean(dma_addr, size);
|
|
}
|
|
|
|
void
|
|
swiotlb_sync_single_range_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
|
|
unsigned long offset, size_t size, int dir)
|
|
{
|
|
swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir,
|
|
SYNC_FOR_CPU);
|
|
}
|
|
|
|
void
|
|
swiotlb_sync_single_range_for_device(struct device *hwdev, dma_addr_t dev_addr,
|
|
unsigned long offset, size_t size, int dir)
|
|
{
|
|
swiotlb_sync_single_range(hwdev, dev_addr, offset, 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_single
|
|
* 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_single are the
|
|
* same here.
|
|
*/
|
|
int
|
|
swiotlb_map_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
|
|
int dir)
|
|
{
|
|
void *addr;
|
|
dma_addr_t dev_addr;
|
|
int i;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
|
|
for (i = 0; i < nelems; i++, sg++) {
|
|
addr = SG_ENT_VIRT_ADDRESS(sg);
|
|
dev_addr = virt_to_bus(addr);
|
|
if (swiotlb_force || address_needs_mapping(hwdev, dev_addr)) {
|
|
void *map = map_single(hwdev, addr, sg->length, dir);
|
|
if (!map) {
|
|
/* Don't panic here, we expect map_sg users
|
|
to do proper error handling. */
|
|
swiotlb_full(hwdev, sg->length, dir, 0);
|
|
swiotlb_unmap_sg(hwdev, sg - i, i, dir);
|
|
sg[0].dma_length = 0;
|
|
return 0;
|
|
}
|
|
sg->dma_address = virt_to_bus(map);
|
|
} else
|
|
sg->dma_address = dev_addr;
|
|
sg->dma_length = 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_single() above.
|
|
*/
|
|
void
|
|
swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nelems,
|
|
int dir)
|
|
{
|
|
int i;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
|
|
for (i = 0; i < nelems; i++, sg++)
|
|
if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
|
|
unmap_single(hwdev, bus_to_virt(sg->dma_address),
|
|
sg->dma_length, dir);
|
|
else if (dir == DMA_FROM_DEVICE)
|
|
dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
|
|
}
|
|
|
|
/*
|
|
* 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 *sg,
|
|
int nelems, int dir, int target)
|
|
{
|
|
int i;
|
|
|
|
BUG_ON(dir == DMA_NONE);
|
|
|
|
for (i = 0; i < nelems; i++, sg++)
|
|
if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
|
|
sync_single(hwdev, bus_to_virt(sg->dma_address),
|
|
sg->dma_length, dir, target);
|
|
else if (dir == DMA_FROM_DEVICE)
|
|
dma_mark_clean(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
|
|
}
|
|
|
|
void
|
|
swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
|
|
int nelems, int 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, int dir)
|
|
{
|
|
swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
|
|
}
|
|
|
|
int
|
|
swiotlb_dma_mapping_error(dma_addr_t dma_addr)
|
|
{
|
|
return (dma_addr == virt_to_bus(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 virt_to_bus(io_tlb_end - 1) <= mask;
|
|
}
|
|
|
|
EXPORT_SYMBOL(swiotlb_map_single);
|
|
EXPORT_SYMBOL(swiotlb_unmap_single);
|
|
EXPORT_SYMBOL(swiotlb_map_sg);
|
|
EXPORT_SYMBOL(swiotlb_unmap_sg);
|
|
EXPORT_SYMBOL(swiotlb_sync_single_for_cpu);
|
|
EXPORT_SYMBOL(swiotlb_sync_single_for_device);
|
|
EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_cpu);
|
|
EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device);
|
|
EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu);
|
|
EXPORT_SYMBOL(swiotlb_sync_sg_for_device);
|
|
EXPORT_SYMBOL(swiotlb_dma_mapping_error);
|
|
EXPORT_SYMBOL(swiotlb_alloc_coherent);
|
|
EXPORT_SYMBOL(swiotlb_free_coherent);
|
|
EXPORT_SYMBOL(swiotlb_dma_supported);
|