linux/lib/swiotlb.c

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/*
* Dynamic DMA mapping support.
*
* This implementation is a fallback for platforms that do not support
* I/O TLBs (aka DMA address translation hardware).
* Copyright (C) 2000 Asit Mallick <Asit.K.Mallick@intel.com>
* Copyright (C) 2000 Goutham Rao <goutham.rao@intel.com>
* Copyright (C) 2000, 2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 03/05/07 davidm Switch from PCI-DMA to generic device DMA API.
* 00/12/13 davidm Rename to swiotlb.c and add mark_clean() to avoid
* unnecessary i-cache flushing.
* 04/07/.. ak Better overflow handling. Assorted fixes.
* 05/09/10 linville Add support for syncing ranges, support syncing for
* DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
*/
#include <linux/cache.h>
#include <linux/dma-mapping.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/swiotlb.h>
#include <linux/string.h>
#include <linux/swiotlb.h>
#include <linux/types.h>
#include <linux/ctype.h>
#include <linux/highmem.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/scatterlist.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/iommu-helper.h>
#define OFFSET(val,align) ((unsigned long) \
( (val) & ( (align) - 1)))
#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
/*
* Minimum IO TLB size to bother booting with. Systems with mainly
* 64bit capable cards will only lightly use the swiotlb. If we can't
* allocate a contiguous 1MB, we're probably in trouble anyway.
*/
#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
/*
* Enumeration for sync targets
*/
enum dma_sync_target {
SYNC_FOR_CPU = 0,
SYNC_FOR_DEVICE = 1,
};
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 struct swiotlb_phys_addr {
struct page *page;
unsigned int offset;
} *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? */
void * __weak swiotlb_alloc_boot(size_t size, unsigned long nslabs)
{
return alloc_bootmem_low_pages(size);
}
void * __weak swiotlb_alloc(unsigned order, unsigned long nslabs)
{
return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
}
dma_addr_t __weak swiotlb_phys_to_bus(phys_addr_t paddr)
{
return paddr;
}
phys_addr_t __weak swiotlb_bus_to_phys(dma_addr_t baddr)
{
return baddr;
}
static dma_addr_t swiotlb_virt_to_bus(volatile void *address)
{
return swiotlb_phys_to_bus(virt_to_phys(address));
}
static void *swiotlb_bus_to_virt(dma_addr_t address)
{
return phys_to_virt(swiotlb_bus_to_phys(address));
}
int __weak swiotlb_arch_range_needs_mapping(void *ptr, size_t size)
{
return 0;
}
static dma_addr_t swiotlb_sg_to_bus(struct scatterlist *sg)
{
return swiotlb_phys_to_bus(page_to_phys(sg_page(sg)) + sg->offset);
}
static void swiotlb_print_info(unsigned long bytes)
{
phys_addr_t pstart, pend;
dma_addr_t bstart, bend;
pstart = virt_to_phys(io_tlb_start);
pend = virt_to_phys(io_tlb_end);
bstart = swiotlb_phys_to_bus(pstart);
bend = swiotlb_phys_to_bus(pend);
printk(KERN_INFO "Placing %luMB software IO TLB between %p - %p\n",
bytes >> 20, io_tlb_start, io_tlb_end);
if (pstart != bstart || pend != bend)
printk(KERN_INFO "software IO TLB at phys %#llx - %#llx"
" bus %#llx - %#llx\n",
(unsigned long long)pstart,
(unsigned long long)pend,
(unsigned long long)bstart,
(unsigned long long)bend);
else
printk(KERN_INFO "software IO TLB at phys %#llx - %#llx\n",
(unsigned long long)pstart,
(unsigned long long)pend);
}
/*
* Statically reserve bounce buffer space and initialize bounce buffer data
* structures for the software IO TLB used to implement the DMA API.
*/
void __init
swiotlb_init_with_default_size(size_t default_size)
{
unsigned long i, bytes;
if (!io_tlb_nslabs) {
io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
}
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
/*
* Get IO TLB memory from the low pages
*/
io_tlb_start = swiotlb_alloc_boot(bytes, io_tlb_nslabs);
if (!io_tlb_start)
panic("Cannot allocate SWIOTLB buffer");
io_tlb_end = io_tlb_start + bytes;
/*
* Allocate and initialize the free list array. This array is used
* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
* between io_tlb_start and io_tlb_end.
*/
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(struct swiotlb_phys_addr));
/*
* Get the overflow emergency buffer
*/
io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
if (!io_tlb_overflow_buffer)
panic("Cannot allocate SWIOTLB overflow buffer!\n");
swiotlb_print_info(bytes);
}
void __init
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, bytes, 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 << IO_TLB_SHIFT);
io_tlb_nslabs = SLABS_PER_PAGE << order;
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
io_tlb_start = swiotlb_alloc(order, io_tlb_nslabs);
if (io_tlb_start)
break;
order--;
}
if (!io_tlb_start)
goto cleanup1;
if (order != get_order(bytes)) {
printk(KERN_WARNING "Warning: only able to allocate %ld MB "
"for software IO TLB\n", (PAGE_SIZE << order) >> 20);
io_tlb_nslabs = SLABS_PER_PAGE << order;
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
}
io_tlb_end = io_tlb_start + bytes;
memset(io_tlb_start, 0, bytes);
/*
* Allocate and initialize the free list array. This array is used
* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
* between io_tlb_start and io_tlb_end.
*/
io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
get_order(io_tlb_nslabs * sizeof(int)));
if (!io_tlb_list)
goto 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 = (struct swiotlb_phys_addr *)__get_free_pages(GFP_KERNEL,
get_order(io_tlb_nslabs * sizeof(struct swiotlb_phys_addr)));
if (!io_tlb_orig_addr)
goto cleanup3;
memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(struct swiotlb_phys_addr));
/*
* 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;
swiotlb_print_info(bytes);
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;
cleanup2:
io_tlb_end = NULL;
free_pages((unsigned long)io_tlb_start, order);
io_tlb_start = NULL;
cleanup1:
io_tlb_nslabs = req_nslabs;
return -ENOMEM;
}
static int
address_needs_mapping(struct device *hwdev, dma_addr_t addr, size_t size)
{
return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
}
static inline int range_needs_mapping(void *ptr, size_t size)
{
return swiotlb_force || swiotlb_arch_range_needs_mapping(ptr, size);
}
static int is_swiotlb_buffer(char *addr)
{
return addr >= io_tlb_start && addr < io_tlb_end;
}
static struct swiotlb_phys_addr swiotlb_bus_to_phys_addr(char *dma_addr)
{
int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
struct swiotlb_phys_addr buffer = io_tlb_orig_addr[index];
buffer.offset += (long)dma_addr & ((1 << IO_TLB_SHIFT) - 1);
buffer.page += buffer.offset >> PAGE_SHIFT;
buffer.offset &= PAGE_SIZE - 1;
return buffer;
}
static void
__sync_single(struct swiotlb_phys_addr buffer, char *dma_addr, size_t size, int dir)
{
if (PageHighMem(buffer.page)) {
size_t len, bytes;
char *dev, *host, *kmp;
len = size;
while (len != 0) {
unsigned long flags;
bytes = len;
if ((bytes + buffer.offset) > PAGE_SIZE)
bytes = PAGE_SIZE - buffer.offset;
local_irq_save(flags); /* protects KM_BOUNCE_READ */
kmp = kmap_atomic(buffer.page, KM_BOUNCE_READ);
dev = dma_addr + size - len;
host = kmp + buffer.offset;
if (dir == DMA_FROM_DEVICE)
memcpy(host, dev, bytes);
else
memcpy(dev, host, bytes);
kunmap_atomic(kmp, KM_BOUNCE_READ);
local_irq_restore(flags);
len -= bytes;
buffer.page++;
buffer.offset = 0;
}
} else {
void *v = page_address(buffer.page) + buffer.offset;
if (dir == DMA_TO_DEVICE)
memcpy(dma_addr, v, size);
else
memcpy(v, dma_addr, size);
}
}
/*
* Allocates bounce buffer and returns its kernel virtual address.
*/
static void *
map_single(struct device *hwdev, struct swiotlb_phys_addr buffer, size_t size, int dir)
{
unsigned long flags;
char *dma_addr;
unsigned int nslots, stride, index, wrap;
int i;
unsigned long start_dma_addr;
unsigned long mask;
unsigned long offset_slots;
unsigned long max_slots;
struct swiotlb_phys_addr slot_buf;
mask = dma_get_seg_boundary(hwdev);
start_dma_addr = swiotlb_virt_to_bus(io_tlb_start) & mask;
offset_slots = ALIGN(start_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
/*
* Carefully handle integer overflow which can occur when mask == ~0UL.
*/
max_slots = mask + 1
? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT
: 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
/*
* For mappings greater than a page, we limit the stride (and
* hence alignment) to a page size.
*/
nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
if (size > PAGE_SIZE)
stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
else
stride = 1;
BUG_ON(!nslots);
/*
* Find suitable number of IO TLB entries size that will fit this
* request and allocate a buffer from that IO TLB pool.
*/
spin_lock_irqsave(&io_tlb_lock, flags);
index = ALIGN(io_tlb_index, stride);
if (index >= io_tlb_nslabs)
index = 0;
wrap = index;
do {
while (iommu_is_span_boundary(index, nslots, offset_slots,
max_slots)) {
index += stride;
if (index >= io_tlb_nslabs)
index = 0;
if (index == wrap)
goto not_found;
}
/*
* If we find a slot that indicates we have 'nslots' number of
* contiguous buffers, we allocate the buffers from that slot
* and mark the entries as '0' indicating unavailable.
*/
if (io_tlb_list[index] >= nslots) {
int count = 0;
for (i = index; i < (int) (index + nslots); i++)
io_tlb_list[i] = 0;
for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--)
io_tlb_list[i] = ++count;
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);
not_found:
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.
*/
slot_buf = buffer;
for (i = 0; i < nslots; i++) {
slot_buf.page += slot_buf.offset >> PAGE_SHIFT;
slot_buf.offset &= PAGE_SIZE - 1;
io_tlb_orig_addr[index+i] = slot_buf;
slot_buf.offset += 1 << IO_TLB_SHIFT;
}
if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
__sync_single(buffer, dma_addr, size, DMA_TO_DEVICE);
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;
struct swiotlb_phys_addr buffer = swiotlb_bus_to_phys_addr(dma_addr);
/*
* First, sync the memory before unmapping the entry
*/
if ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))
/*
* bounce... copy the data back into the original buffer * and
* delete the bounce buffer.
*/
__sync_single(buffer, dma_addr, size, DMA_FROM_DEVICE);
/*
* 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 target)
{
struct swiotlb_phys_addr buffer = swiotlb_bus_to_phys_addr(dma_addr);
switch (target) {
case SYNC_FOR_CPU:
if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
__sync_single(buffer, dma_addr, size, DMA_FROM_DEVICE);
else
BUG_ON(dir != DMA_TO_DEVICE);
break;
case SYNC_FOR_DEVICE:
if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
__sync_single(buffer, dma_addr, size, DMA_TO_DEVICE);
else
BUG_ON(dir != DMA_FROM_DEVICE);
break;
default:
BUG();
}
}
void *
swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags)
{
dma_addr_t dev_addr;
void *ret;
int order = get_order(size);
u64 dma_mask = DMA_32BIT_MASK;
if (hwdev && hwdev->coherent_dma_mask)
dma_mask = hwdev->coherent_dma_mask;
ret = (void *)__get_free_pages(flags, order);
if (ret && !is_buffer_dma_capable(dma_mask, swiotlb_virt_to_bus(ret), size)) {
/*
* 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.
*/
struct swiotlb_phys_addr buffer;
buffer.page = virt_to_page(NULL);
buffer.offset = 0;
ret = map_single(hwdev, buffer, size, DMA_FROM_DEVICE);
if (!ret)
return NULL;
}
memset(ret, 0, size);
dev_addr = swiotlb_virt_to_bus(ret);
/* Confirm address can be DMA'd by device */
if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
(unsigned long long)dma_mask,
(unsigned long long)dev_addr);
/* DMA_TO_DEVICE to avoid memcpy in unmap_single */
unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
return NULL;
}
*dma_handle = dev_addr;
return ret;
}
void
swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
dma_addr_t dma_handle)
{
WARN_ON(irqs_disabled());
if (!is_swiotlb_buffer(vaddr))
free_pages((unsigned long) vaddr, get_order(size));
else
/* DMA_TO_DEVICE to avoid memcpy in unmap_single */
unmap_single(hwdev, vaddr, 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_attrs(struct device *hwdev, void *ptr, size_t size,
int dir, struct dma_attrs *attrs)
{
dma_addr_t dev_addr = swiotlb_virt_to_bus(ptr);
void *map;
struct swiotlb_phys_addr buffer;
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, size) &&
!range_needs_mapping(ptr, size))
return dev_addr;
/*
* Oh well, have to allocate and map a bounce buffer.
*/
buffer.page = virt_to_page(ptr);
buffer.offset = (unsigned long)ptr & ~PAGE_MASK;
map = map_single(hwdev, buffer, size, dir);
if (!map) {
swiotlb_full(hwdev, size, dir, 1);
map = io_tlb_overflow_buffer;
}
dev_addr = swiotlb_virt_to_bus(map);
/*
* Ensure that the address returned is DMA'ble
*/
if (address_needs_mapping(hwdev, dev_addr, size))
panic("map_single: bounce buffer is not DMA'ble");
return dev_addr;
}
EXPORT_SYMBOL(swiotlb_map_single_attrs);
dma_addr_t
swiotlb_map_single(struct device *hwdev, void *ptr, size_t size, int dir)
{
return swiotlb_map_single_attrs(hwdev, ptr, size, dir, NULL);
}
/*
* 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_attrs(struct device *hwdev, dma_addr_t dev_addr,
size_t size, int dir, struct dma_attrs *attrs)
{
char *dma_addr = swiotlb_bus_to_virt(dev_addr);
BUG_ON(dir == DMA_NONE);
if (is_swiotlb_buffer(dma_addr))
unmap_single(hwdev, dma_addr, size, dir);
else if (dir == DMA_FROM_DEVICE)
dma_mark_clean(dma_addr, size);
}
EXPORT_SYMBOL(swiotlb_unmap_single_attrs);
void
swiotlb_unmap_single(struct device *hwdev, dma_addr_t dev_addr, size_t size,
int dir)
{
return swiotlb_unmap_single_attrs(hwdev, dev_addr, size, dir, NULL);
}
/*
* 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 = swiotlb_bus_to_virt(dev_addr);
BUG_ON(dir == DMA_NONE);
if (is_swiotlb_buffer(dma_addr))
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 = swiotlb_bus_to_virt(dev_addr) + offset;
BUG_ON(dir == DMA_NONE);
if (is_swiotlb_buffer(dma_addr))
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);
}
void swiotlb_unmap_sg_attrs(struct device *, struct scatterlist *, int, int,
struct dma_attrs *);
/*
* 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_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
int dir, struct dma_attrs *attrs)
{
struct scatterlist *sg;
struct swiotlb_phys_addr buffer;
dma_addr_t dev_addr;
int i;
BUG_ON(dir == DMA_NONE);
for_each_sg(sgl, sg, nelems, i) {
dev_addr = swiotlb_sg_to_bus(sg);
if (range_needs_mapping(sg_virt(sg), sg->length) ||
address_needs_mapping(hwdev, dev_addr, sg->length)) {
void *map;
buffer.page = sg_page(sg);
buffer.offset = sg->offset;
map = map_single(hwdev, buffer, 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_attrs(hwdev, sgl, i, dir,
attrs);
sgl[0].dma_length = 0;
return 0;
}
sg->dma_address = swiotlb_virt_to_bus(map);
} else
sg->dma_address = dev_addr;
sg->dma_length = sg->length;
}
return nelems;
}
EXPORT_SYMBOL(swiotlb_map_sg_attrs);
int
swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
int dir)
{
return swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL);
}
/*
* 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_attrs(struct device *hwdev, struct scatterlist *sgl,
int nelems, int dir, struct dma_attrs *attrs)
{
struct scatterlist *sg;
int i;
BUG_ON(dir == DMA_NONE);
for_each_sg(sgl, sg, nelems, i) {
if (sg->dma_address != swiotlb_sg_to_bus(sg))
unmap_single(hwdev, swiotlb_bus_to_virt(sg->dma_address),
sg->dma_length, dir);
else if (dir == DMA_FROM_DEVICE)
dma_mark_clean(swiotlb_bus_to_virt(sg->dma_address), sg->dma_length);
}
}
EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
void
swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
int dir)
{
return swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL);
}
/*
* Make physical memory consistent for a set of streaming mode DMA translations
* after a transfer.
*
* The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
* and usage.
*/
static void
swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
int nelems, int dir, int target)
{
struct scatterlist *sg;
int i;
BUG_ON(dir == DMA_NONE);
for_each_sg(sgl, sg, nelems, i) {
if (sg->dma_address != swiotlb_sg_to_bus(sg))
sync_single(hwdev, swiotlb_bus_to_virt(sg->dma_address),
sg->dma_length, dir, target);
else if (dir == DMA_FROM_DEVICE)
dma_mark_clean(swiotlb_bus_to_virt(sg->dma_address), 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
dma-mapping: add the device argument to dma_mapping_error() Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER architecture does: This enables us to cleanly fix the Calgary IOMMU issue that some devices are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423). I think that per-device dma_mapping_ops support would be also helpful for KVM people to support PCI passthrough but Andi thinks that this makes it difficult to support the PCI passthrough (see the above thread). So I CC'ed this to KVM camp. Comments are appreciated. A pointer to dma_mapping_ops to struct dev_archdata is added. If the pointer is non NULL, DMA operations in asm/dma-mapping.h use it. If it's NULL, the system-wide dma_ops pointer is used as before. If it's useful for KVM people, I plan to implement a mechanism to register a hook called when a new pci (or dma capable) device is created (it works with hot plugging). It enables IOMMUs to set up an appropriate dma_mapping_ops per device. The major obstacle is that dma_mapping_error doesn't take a pointer to the device unlike other DMA operations. So x86 can't have dma_mapping_ops per device. Note all the POWER IOMMUs use the same dma_mapping_error function so this is not a problem for POWER but x86 IOMMUs use different dma_mapping_error functions. The first patch adds the device argument to dma_mapping_error. The patch is trivial but large since it touches lots of drivers and dma-mapping.h in all the architecture. This patch: dma_mapping_error() doesn't take a pointer to the device unlike other DMA operations. So we can't have dma_mapping_ops per device. Note that POWER already has dma_mapping_ops per device but all the POWER IOMMUs use the same dma_mapping_error function. x86 IOMMUs use device argument. [akpm@linux-foundation.org: fix sge] [akpm@linux-foundation.org: fix svc_rdma] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix bnx2x] [akpm@linux-foundation.org: fix s2io] [akpm@linux-foundation.org: fix pasemi_mac] [akpm@linux-foundation.org: fix sdhci] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix sparc] [akpm@linux-foundation.org: fix ibmvscsi] Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 04:44:49 +02:00
swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
{
return (dma_addr == swiotlb_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 swiotlb_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);