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yaml
---
r: 126794
b: refs/heads/master
c: bc40ac6
h: refs/heads/master
v: v3
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Becky Bruce authored and Ingo Molnar committed Dec 28, 2008
1 parent 2107009 commit 2c6de89
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Showing 2 changed files with 31 additions and 91 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 70a7d3cc1308a55104fbe505d76f2aca8a4cf53e
refs/heads/master: bc40ac66988a7721f2a244b6df65f8c13d16479c
120 changes: 30 additions & 90 deletions trunk/lib/swiotlb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -89,10 +89,7 @@ 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;
static phys_addr_t *io_tlb_orig_addr;

/*
* Protect the above data structures in the map and unmap calls
Expand Down Expand Up @@ -204,7 +201,7 @@ swiotlb_init_with_default_size(size_t default_size)
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));
io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(phys_addr_t));

/*
* Get the overflow emergency buffer
Expand Down Expand Up @@ -278,12 +275,14 @@ swiotlb_late_init_with_default_size(size_t default_size)
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)));
io_tlb_orig_addr = (phys_addr_t *)
__get_free_pages(GFP_KERNEL,
get_order(io_tlb_nslabs *
sizeof(phys_addr_t)));
if (!io_tlb_orig_addr)
goto cleanup3;

memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(struct swiotlb_phys_addr));
memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));

/*
* Get the overflow emergency buffer
Expand All @@ -298,8 +297,8 @@ swiotlb_late_init_with_default_size(size_t default_size)
return 0;

cleanup4:
free_pages((unsigned long)io_tlb_orig_addr, get_order(io_tlb_nslabs *
sizeof(char *)));
free_pages((unsigned long)io_tlb_orig_addr,
get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
io_tlb_orig_addr = NULL;
cleanup3:
free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
Expand Down Expand Up @@ -330,59 +329,11 @@ 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)
map_single(struct device *hwdev, phys_addr_t phys, size_t size, int dir)
{
unsigned long flags;
char *dma_addr;
Expand All @@ -392,7 +343,6 @@ map_single(struct device *hwdev, struct swiotlb_phys_addr buffer, size_t size, i
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(hwdev, io_tlb_start) & mask;
Expand Down Expand Up @@ -477,15 +427,10 @@ map_single(struct device *hwdev, struct swiotlb_phys_addr buffer, size_t size, i
* 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;
}
for (i = 0; i < nslots; i++)
io_tlb_orig_addr[index+i] = phys + (i << IO_TLB_SHIFT);
if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
__sync_single(buffer, dma_addr, size, DMA_TO_DEVICE);
memcpy(dma_addr, phys_to_virt(phys), size);

return dma_addr;
}
Expand All @@ -499,17 +444,17 @@ 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);
phys_addr_t phys = io_tlb_orig_addr[index];

/*
* First, sync the memory before unmapping the entry
*/
if ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))
if (phys && ((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);
memcpy(phys_to_virt(phys), dma_addr, size);

/*
* Return the buffer to the free list by setting the corresponding
Expand Down Expand Up @@ -541,18 +486,21 @@ 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);
int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
phys_addr_t phys = io_tlb_orig_addr[index];

phys += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));

switch (target) {
case SYNC_FOR_CPU:
if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
__sync_single(buffer, dma_addr, size, DMA_FROM_DEVICE);
memcpy(phys_to_virt(phys), dma_addr, size);
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);
memcpy(dma_addr, phys_to_virt(phys), size);
else
BUG_ON(dir != DMA_FROM_DEVICE);
break;
Expand Down Expand Up @@ -591,10 +539,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
* 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);
ret = map_single(hwdev, 0, size, DMA_FROM_DEVICE);
if (!ret)
return NULL;
}
Expand Down Expand Up @@ -662,7 +607,6 @@ swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size,
{
dma_addr_t dev_addr = swiotlb_virt_to_bus(hwdev, ptr);
void *map;
struct swiotlb_phys_addr buffer;

BUG_ON(dir == DMA_NONE);
/*
Expand All @@ -677,9 +621,7 @@ swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size,
/*
* 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);
map = map_single(hwdev, virt_to_phys(ptr), size, dir);
if (!map) {
swiotlb_full(hwdev, size, dir, 1);
map = io_tlb_overflow_buffer;
Expand Down Expand Up @@ -824,20 +766,18 @@ 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(hwdev, sg);
if (range_needs_mapping(sg_virt(sg), sg->length) ||
void *addr = sg_virt(sg);
dma_addr_t dev_addr = swiotlb_virt_to_bus(hwdev, addr);

if (range_needs_mapping(addr, 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);
void *map = map_single(hwdev, sg_phys(sg),
sg->length, dir);
if (!map) {
/* Don't panic here, we expect map_sg users
to do proper error handling. */
Expand Down

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