[patch 2.6.14-rc2 1/6] swiotlb: move from arch/ia64/lib/ to lib/

From: John W. Linville <linville_at_tuxdriver.com>
Date: 2005-09-29 07:50:48
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>
---

 arch/ia64/Kconfig           |    4 
 arch/ia64/lib/Makefile      |    2 
 arch/ia64/lib/swiotlb.c     |  657 --------------------------------------------
 arch/x86_64/kernel/Makefile |    2 
 lib/Makefile                |    2 
 lib/swiotlb.c               |  657 ++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 664 insertions(+), 660 deletions(-)

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -26,6 +26,10 @@ config MMU
 	bool
 	default y
 
+config SWIOTLB
+       bool
+       default y
+
 config RWSEM_XCHGADD_ALGORITHM
 	bool
 	default y
diff --git a/arch/ia64/lib/Makefile b/arch/ia64/lib/Makefile
--- a/arch/ia64/lib/Makefile
+++ b/arch/ia64/lib/Makefile
@@ -9,7 +9,7 @@ lib-y := __divsi3.o __udivsi3.o __modsi3
 	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
--- a/arch/ia64/lib/swiotlb.c
+++ b/arch/ia64/lib/swiotlb.c
@@ -1,657 +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
-
-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 */
-}
-
-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);
diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile
--- a/arch/x86_64/kernel/Makefile
+++ b/arch/x86_64/kernel/Makefile
@@ -27,7 +27,6 @@ obj-$(CONFIG_CPU_FREQ)		+= cpufreq/
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 obj-$(CONFIG_GART_IOMMU)	+= pci-gart.o aperture.o
 obj-$(CONFIG_DUMMY_IOMMU)	+= pci-nommu.o pci-dma.o
-obj-$(CONFIG_SWIOTLB)		+= swiotlb.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_X86_PM_TIMER)	+= pmtimer.o
 
@@ -41,7 +40,6 @@ CFLAGS_vsyscall.o		:= $(PROFILING) -g0
 bootflag-y			+= ../../i386/kernel/bootflag.o
 cpuid-$(subst m,y,$(CONFIG_X86_CPUID))  += ../../i386/kernel/cpuid.o
 topology-y                     += ../../i386/mach-default/topology.o
-swiotlb-$(CONFIG_SWIOTLB)      += ../../ia64/lib/swiotlb.o
 microcode-$(subst m,y,$(CONFIG_MICROCODE))  += ../../i386/kernel/microcode.o
 intel_cacheinfo-y		+= ../../i386/kernel/cpu/intel_cacheinfo.o
 quirks-y			+= ../../i386/kernel/quirks.o
diff --git a/lib/Makefile b/lib/Makefile
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -44,6 +44,8 @@ obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o
 obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o
 obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o
 
+obj-$(CONFIG_SWIOTLB) += swiotlb.o
+
 hostprogs-y	:= gen_crc32table
 clean-files	:= crc32table.h
 
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -0,0 +1,657 @@
+/*
+ * 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
+
+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 */
+}
+
+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);
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Received on Thu Sep 29 07:58:18 2005

This archive was generated by hypermail 2.1.8 : 2005-09-29 07:58:55 EST