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authorJohn W. Linville <linville@tuxdriver.com>2005-09-29 14:42:42 -0700
committerTony Luck <tony.luck@intel.com>2005-09-29 14:42:42 -0700
commit6c654b5fdf093cd05f35f7c9c2a00182fa5636dc (patch)
tree7aa16a41d64b906c6e7e5248897f88027428d12a /arch/ia64/lib
parent0b9afede3d9c66fef06f1d5ef5ff15c4b97730fc (diff)
[PATCH] swiotlb: move from arch/ia64/lib/ to lib/
The swiotlb implementation is shared by both IA-64 and EM64T. However, the source itself lives under arch/ia64. This patch moves swiotlb.c from arch/ia64/lib to lib/ and fixes-up the appropriate Makefile and Kconfig files. No actual changes are made to swiotlb.c. Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/lib')
-rw-r--r--arch/ia64/lib/Makefile2
-rw-r--r--arch/ia64/lib/swiotlb.c759
2 files changed, 1 insertions, 760 deletions
diff --git a/arch/ia64/lib/Makefile b/arch/ia64/lib/Makefile
index 799407e7726..4be1546e172 100644
--- a/arch/ia64/lib/Makefile
+++ b/arch/ia64/lib/Makefile
@@ -9,7 +9,7 @@ lib-y := __divsi3.o __udivsi3.o __modsi3.o __umodsi3.o \
bitop.o checksum.o clear_page.o csum_partial_copy.o \
clear_user.o strncpy_from_user.o strlen_user.o strnlen_user.o \
flush.o ip_fast_csum.o do_csum.o \
- memset.o strlen.o swiotlb.o
+ memset.o strlen.o
lib-$(CONFIG_ITANIUM) += copy_page.o copy_user.o memcpy.o
lib-$(CONFIG_MCKINLEY) += copy_page_mck.o memcpy_mck.o
diff --git a/arch/ia64/lib/swiotlb.c b/arch/ia64/lib/swiotlb.c
deleted file mode 100644
index 875b0c16250..00000000000
--- a/arch/ia64/lib/swiotlb.c
+++ /dev/null
@@ -1,759 +0,0 @@
-/*
- * Dynamic DMA mapping support.
- *
- * This implementation is for IA-64 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.
- */
-
-#include <linux/cache.h>
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/pci.h>
-#include <linux/spinlock.h>
-#include <linux/string.h>
-#include <linux/types.h>
-#include <linux/ctype.h>
-
-#include <asm/io.h>
-#include <asm/pci.h>
-#include <asm/dma.h>
-
-#include <linux/init.h>
-#include <linux/bootmem.h>
-
-#define OFFSET(val,align) ((unsigned long) \
- ( (val) & ( (align) - 1)))
-
-#define SG_ENT_VIRT_ADDRESS(sg) (page_address((sg)->page) + (sg)->offset)
-#define SG_ENT_PHYS_ADDRESS(SG) virt_to_phys(SG_ENT_VIRT_ADDRESS(SG))
-
-/*
- * Maximum allowable number of contiguous slabs to map,
- * must be a power of 2. What is the appropriate value ?
- * The complexity of {map,unmap}_single is linearly dependent on this value.
- */
-#define IO_TLB_SEGSIZE 128
-
-/*
- * log of the size of each IO TLB slab. The number of slabs is command line
- * controllable.
- */
-#define IO_TLB_SHIFT 11
-
-#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
-
-/*
- * Minimum IO TLB size to bother booting with. Systems with mainly
- * 64bit capable cards will only lightly use the swiotlb. If we can't
- * allocate a contiguous 1MB, we're probably in trouble anyway.
- */
-#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
-
-int swiotlb_force;
-
-/*
- * Used to do a quick range check in swiotlb_unmap_single and
- * swiotlb_sync_single_*, to see if the memory was in fact allocated by this
- * API.
- */
-static char *io_tlb_start, *io_tlb_end;
-
-/*
- * The number of IO TLB blocks (in groups of 64) betweeen 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;
-
-void *io_tlb_overflow_buffer;
-
-/*
- * This is a free list describing the number of free entries available from
- * each index
- */
-static unsigned int *io_tlb_list;
-static unsigned int io_tlb_index;
-
-/*
- * We need to save away the original address corresponding to a mapped entry
- * for the sync operations.
- */
-static unsigned char **io_tlb_orig_addr;
-
-/*
- * Protect the above data structures in the map and unmap calls
- */
-static DEFINE_SPINLOCK(io_tlb_lock);
-
-static int __init
-setup_io_tlb_npages(char *str)
-{
- if (isdigit(*str)) {
- io_tlb_nslabs = simple_strtoul(str, &str, 0);
- /* avoid tail segment of size < IO_TLB_SEGSIZE */
- io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
- }
- if (*str == ',')
- ++str;
- if (!strcmp(str, "force"))
- swiotlb_force = 1;
- return 1;
-}
-__setup("swiotlb=", setup_io_tlb_npages);
-/* make io_tlb_overflow tunable too? */
-
-/*
- * Statically reserve bounce buffer space and initialize bounce buffer data
- * structures for the software IO TLB used to implement the PCI DMA API.
- */
-void
-swiotlb_init_with_default_size (size_t default_size)
-{
- unsigned long i;
-
- 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
- */
- io_tlb_start = alloc_bootmem_low_pages(io_tlb_nslabs *
- (1 << IO_TLB_SHIFT));
- if (!io_tlb_start)
- panic("Cannot allocate SWIOTLB buffer");
- io_tlb_end = io_tlb_start + io_tlb_nslabs * (1 << IO_TLB_SHIFT);
-
- /*
- * 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 = alloc_bootmem(io_tlb_nslabs * sizeof(int));
- for (i = 0; i < io_tlb_nslabs; i++)
- io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
- io_tlb_index = 0;
- io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(char *));
-
- /*
- * Get the overflow emergency buffer
- */
- io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
- printk(KERN_INFO "Placing software IO TLB between 0x%lx - 0x%lx\n",
- virt_to_phys(io_tlb_start), virt_to_phys(io_tlb_end));
-}
-
-void
-swiotlb_init (void)
-{
- swiotlb_init_with_default_size(64 * (1<<20)); /* default to 64MB */
-}
-
-/*
- * 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 i, req_nslabs = io_tlb_nslabs;
- unsigned int order;
-
- 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 * (1 << IO_TLB_SHIFT));
- io_tlb_nslabs = SLABS_PER_PAGE << order;
-
- while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
- io_tlb_start = (char *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
- order);
- if (io_tlb_start)
- break;
- order--;
- }
-
- if (!io_tlb_start)
- goto cleanup1;
-
- if (order != get_order(io_tlb_nslabs * (1 << IO_TLB_SHIFT))) {
- 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;
- }
- io_tlb_end = io_tlb_start + io_tlb_nslabs * (1 << IO_TLB_SHIFT);
- memset(io_tlb_start, 0, io_tlb_nslabs * (1 << IO_TLB_SHIFT));
-
- /*
- * 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 cleanup2;
-
- for (i = 0; i < io_tlb_nslabs; i++)
- io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
- io_tlb_index = 0;
-
- io_tlb_orig_addr = (unsigned char **)__get_free_pages(GFP_KERNEL,
- get_order(io_tlb_nslabs * sizeof(char *)));
- if (!io_tlb_orig_addr)
- goto cleanup3;
-
- memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(char *));
-
- /*
- * Get the overflow emergency buffer
- */
- io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
- get_order(io_tlb_overflow));
- if (!io_tlb_overflow_buffer)
- goto cleanup4;
-
- printk(KERN_INFO "Placing %ldMB software IO TLB between 0x%lx - "
- "0x%lx\n", (io_tlb_nslabs * (1 << IO_TLB_SHIFT)) >> 20,
- virt_to_phys(io_tlb_start), virt_to_phys(io_tlb_end));
-
- return 0;
-
-cleanup4:
- free_pages((unsigned long)io_tlb_orig_addr, get_order(io_tlb_nslabs *
- sizeof(char *)));
- io_tlb_orig_addr = NULL;
-cleanup3:
- free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
- sizeof(int)));
- io_tlb_list = NULL;
- io_tlb_end = NULL;
-cleanup2:
- free_pages((unsigned long)io_tlb_start, order);
- io_tlb_start = NULL;
-cleanup1:
- io_tlb_nslabs = req_nslabs;
- return -ENOMEM;
-}
-
-static inline int
-address_needs_mapping(struct device *hwdev, dma_addr_t addr)
-{
- dma_addr_t mask = 0xffffffff;
- /* If the device has a mask, use it, otherwise default to 32 bits */
- if (hwdev && hwdev->dma_mask)
- mask = *hwdev->dma_mask;
- return (addr & ~mask) != 0;
-}
-
-/*
- * Allocates bounce buffer and returns its kernel virtual address.
- */
-static void *
-map_single(struct device *hwdev, char *buffer, size_t size, int dir)
-{
- unsigned long flags;
- char *dma_addr;
- unsigned int nslots, stride, index, wrap;
- int i;
-
- /*
- * For mappings greater than 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;
-
- if (!nslots)
- BUG();
-
- /*
- * 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);
- {
- wrap = index = ALIGN(io_tlb_index, stride);
-
- if (index >= io_tlb_nslabs)
- wrap = index = 0;
-
- do {
- /*
- * 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;
- dma_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);
-
- spin_unlock_irqrestore(&io_tlb_lock, flags);
- return NULL;
- }
- 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.
- */
- io_tlb_orig_addr[index] = buffer;
- if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
- memcpy(dma_addr, buffer, size);
-
- return dma_addr;
-}
-
-/*
- * dma_addr is the kernel virtual address of the bounce buffer to unmap.
- */
-static void
-unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
-{
- unsigned long flags;
- int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
- int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
- char *buffer = io_tlb_orig_addr[index];
-
- /*
- * First, sync the memory before unmapping the entry
- */
- if (buffer && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
- /*
- * bounce... copy the data back into the original buffer * and
- * delete the bounce buffer.
- */
- memcpy(buffer, dma_addr, size);
-
- /*
- * Return the buffer to the free list by setting the corresponding
- * entries to indicate the number of contigous 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;
- /*
- * 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);
-}
-
-static void
-sync_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
-{
- int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
- char *buffer = io_tlb_orig_addr[index];
-
- /*
- * bounce... copy the data back into/from the original buffer
- * XXX How do you handle DMA_BIDIRECTIONAL here ?
- */
- if (dir == DMA_FROM_DEVICE)
- memcpy(buffer, dma_addr, size);
- else if (dir == DMA_TO_DEVICE)
- memcpy(dma_addr, buffer, size);
- else
- BUG();
-}
-
-void *
-swiotlb_alloc_coherent(struct device *hwdev, size_t size,
- dma_addr_t *dma_handle, int flags)
-{
- unsigned long dev_addr;
- void *ret;
- int order = get_order(size);
-
- /*
- * XXX fix me: the DMA API should pass us an explicit DMA mask
- * instead, or use ZONE_DMA32 (ia64 overloads ZONE_DMA to be a ~32
- * bit range instead of a 16MB one).
- */
- flags |= GFP_DMA;
-
- ret = (void *)__get_free_pages(flags, order);
- if (ret && address_needs_mapping(hwdev, virt_to_phys(ret))) {
- /*
- * The allocated memory isn't reachable by the device.
- * Fall back on swiotlb_map_single().
- */
- free_pages((unsigned long) ret, order);
- ret = NULL;
- }
- if (!ret) {
- /*
- * We are either out of memory or the device can't DMA
- * to GFP_DMA memory; fall back on
- * swiotlb_map_single(), which will grab memory from
- * the lowest available address range.
- */
- dma_addr_t handle;
- handle = swiotlb_map_single(NULL, NULL, size, DMA_FROM_DEVICE);
- if (dma_mapping_error(handle))
- return NULL;
-
- ret = phys_to_virt(handle);
- }
-
- memset(ret, 0, size);
- dev_addr = virt_to_phys(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, 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 pci_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 "PCI-DMA: Out of SW-IOMMU space for %lu bytes at "
- "device %s\n", size, dev ? dev->bus_id : "?");
-
- if (size > io_tlb_overflow && do_panic) {
- if (dir == PCI_DMA_FROMDEVICE || dir == PCI_DMA_BIDIRECTIONAL)
- panic("PCI-DMA: Memory would be corrupted\n");
- if (dir == PCI_DMA_TODEVICE || dir == PCI_DMA_BIDIRECTIONAL)
- panic("PCI-DMA: Random memory would be DMAed\n");
- }
-}
-
-/*
- * Map a single buffer of the indicated size for DMA in streaming mode. The
- * PCI 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)
-{
- unsigned long dev_addr = virt_to_phys(ptr);
- void *map;
-
- if (dir == DMA_NONE)
- BUG();
- /*
- * 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_phys(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;
-}
-
-/*
- * Since DMA is i-cache coherent, any (complete) pages that were written via
- * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
- * flush them when they get mapped into an executable vm-area.
- */
-static void
-mark_clean(void *addr, size_t size)
-{
- unsigned long pg_addr, end;
-
- pg_addr = PAGE_ALIGN((unsigned long) addr);
- end = (unsigned long) addr + size;
- while (pg_addr + PAGE_SIZE <= end) {
- struct page *page = virt_to_page(pg_addr);
- set_bit(PG_arch_1, &page->flags);
- pg_addr += PAGE_SIZE;
- }
-}
-
-/*
- * 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 = phys_to_virt(dev_addr);
-
- if (dir == DMA_NONE)
- BUG();
- if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
- unmap_single(hwdev, dma_addr, size, dir);
- else if (dir == DMA_FROM_DEVICE)
- 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 PCI dma mapping, you must
- * call this function before doing so. At the next point you give the PCI dma
- * address back to the card, you must first perform a
- * swiotlb_dma_sync_for_device, and then the device again owns the buffer
- */
-void
-swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
- size_t size, int dir)
-{
- char *dma_addr = phys_to_virt(dev_addr);
-
- if (dir == DMA_NONE)
- BUG();
- if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
- sync_single(hwdev, dma_addr, size, dir);
- else if (dir == DMA_FROM_DEVICE)
- mark_clean(dma_addr, size);
-}
-
-void
-swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
- size_t size, int dir)
-{
- char *dma_addr = phys_to_virt(dev_addr);
-
- if (dir == DMA_NONE)
- BUG();
- if (dma_addr >= io_tlb_start && dma_addr < io_tlb_end)
- sync_single(hwdev, dma_addr, size, dir);
- else if (dir == DMA_FROM_DEVICE)
- mark_clean(dma_addr, size);
-}
-
-/*
- * 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;
- unsigned long dev_addr;
- int i;
-
- if (dir == DMA_NONE)
- BUG();
-
- for (i = 0; i < nelems; i++, sg++) {
- addr = SG_ENT_VIRT_ADDRESS(sg);
- dev_addr = virt_to_phys(addr);
- if (swiotlb_force || address_needs_mapping(hwdev, dev_addr)) {
- sg->dma_address = (dma_addr_t) virt_to_phys(map_single(hwdev, addr, sg->length, dir));
- if (!sg->dma_address) {
- /* 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;
- }
- } 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;
-
- if (dir == DMA_NONE)
- BUG();
-
- for (i = 0; i < nelems; i++, sg++)
- if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
- unmap_single(hwdev, (void *) phys_to_virt(sg->dma_address), sg->dma_length, dir);
- else if (dir == DMA_FROM_DEVICE)
- 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.
- */
-void
-swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
- int nelems, int dir)
-{
- int i;
-
- if (dir == DMA_NONE)
- BUG();
-
- for (i = 0; i < nelems; i++, sg++)
- if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
- sync_single(hwdev, (void *) sg->dma_address,
- sg->dma_length, dir);
-}
-
-void
-swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
- int nelems, int dir)
-{
- int i;
-
- if (dir == DMA_NONE)
- BUG();
-
- for (i = 0; i < nelems; i++, sg++)
- if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
- sync_single(hwdev, (void *) sg->dma_address,
- sg->dma_length, dir);
-}
-
-int
-swiotlb_dma_mapping_error(dma_addr_t dma_addr)
-{
- return (dma_addr == virt_to_phys(io_tlb_overflow_buffer));
-}
-
-/*
- * Return whether the given PCI device DMA address mask can be supported
- * properly. For example, if your device can only drive the low 24-bits
- * during PCI 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_phys (io_tlb_end) - 1) <= mask;
-}
-
-EXPORT_SYMBOL(swiotlb_init);
-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(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);