swiotlb: support bouncing of HighMem pages
Impact: prepare the swiotlb code for HighMem struct pages This requires us to treat DMA regions in terms of page+offset rather than virtual addressing since a HighMem page may not have a mapping. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Jeremy Fitzhardinge
Ingo Molnar
parent
1b548f667c
commit
ef9b189352
1 changed files with 89 additions and 33 deletions
122
lib/swiotlb.c
122
lib/swiotlb.c
|
|
@ -26,6 +26,7 @@
|
|||
#include <linux/swiotlb.h>
|
||||
#include <linux/types.h>
|
||||
#include <linux/ctype.h>
|
||||
#include <linux/highmem.h>
|
||||
|
||||
#include <asm/io.h>
|
||||
#include <asm/dma.h>
|
||||
|
|
@ -38,9 +39,6 @@
|
|||
#define OFFSET(val,align) ((unsigned long) \
|
||||
( (val) & ( (align) - 1)))
|
||||
|
||||
#define SG_ENT_VIRT_ADDRESS(sg) (sg_virt((sg)))
|
||||
#define SG_ENT_PHYS_ADDRESS(sg) virt_to_bus(SG_ENT_VIRT_ADDRESS(sg))
|
||||
|
||||
#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
|
||||
|
||||
/*
|
||||
|
|
@ -91,7 +89,10 @@ 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;
|
||||
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
|
||||
|
|
@ -150,6 +151,11 @@ 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);
|
||||
}
|
||||
|
||||
/*
|
||||
* Statically reserve bounce buffer space and initialize bounce buffer data
|
||||
* structures for the software IO TLB used to implement the DMA API.
|
||||
|
|
@ -183,7 +189,7 @@ 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(char *));
|
||||
io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(struct swiotlb_phys_addr));
|
||||
|
||||
/*
|
||||
* Get the overflow emergency buffer
|
||||
|
|
@ -258,12 +264,12 @@ 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 = (unsigned char **)__get_free_pages(GFP_KERNEL,
|
||||
get_order(io_tlb_nslabs * sizeof(char *)));
|
||||
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(char *));
|
||||
memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(struct swiotlb_phys_addr));
|
||||
|
||||
/*
|
||||
* Get the overflow emergency buffer
|
||||
|
|
@ -312,20 +318,59 @@ static int is_swiotlb_buffer(char *addr)
|
|||
return addr >= io_tlb_start && addr < io_tlb_end;
|
||||
}
|
||||
|
||||
static void
|
||||
__sync_single(char *buffer, char *dma_addr, size_t size, int dir)
|
||||
static struct swiotlb_phys_addr swiotlb_bus_to_phys_addr(char *dma_addr)
|
||||
{
|
||||
if (dir == DMA_TO_DEVICE)
|
||||
memcpy(dma_addr, buffer, size);
|
||||
else
|
||||
memcpy(buffer, dma_addr, size);
|
||||
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, char *buffer, size_t size, int dir)
|
||||
map_single(struct device *hwdev, struct swiotlb_phys_addr buffer, size_t size, int dir)
|
||||
{
|
||||
unsigned long flags;
|
||||
char *dma_addr;
|
||||
|
|
@ -335,6 +380,7 @@ map_single(struct device *hwdev, char *buffer, size_t size, int dir)
|
|||
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;
|
||||
|
|
@ -419,8 +465,13 @@ map_single(struct device *hwdev, char *buffer, size_t size, int dir)
|
|||
* This is needed when we sync the memory. Then we sync the buffer if
|
||||
* needed.
|
||||
*/
|
||||
for (i = 0; i < nslots; i++)
|
||||
io_tlb_orig_addr[index+i] = buffer + (i << IO_TLB_SHIFT);
|
||||
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);
|
||||
|
||||
|
|
@ -436,12 +487,12 @@ 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];
|
||||
struct swiotlb_phys_addr buffer = swiotlb_bus_to_phys_addr(dma_addr);
|
||||
|
||||
/*
|
||||
* First, sync the memory before unmapping the entry
|
||||
*/
|
||||
if (buffer && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
|
||||
if ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))
|
||||
/*
|
||||
* bounce... copy the data back into the original buffer * and
|
||||
* delete the bounce buffer.
|
||||
|
|
@ -478,10 +529,7 @@ static void
|
|||
sync_single(struct device *hwdev, char *dma_addr, size_t size,
|
||||
int dir, int target)
|
||||
{
|
||||
int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
|
||||
char *buffer = io_tlb_orig_addr[index];
|
||||
|
||||
buffer += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));
|
||||
struct swiotlb_phys_addr buffer = swiotlb_bus_to_phys_addr(dma_addr);
|
||||
|
||||
switch (target) {
|
||||
case SYNC_FOR_CPU:
|
||||
|
|
@ -529,7 +577,10 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
|
|||
* swiotlb_map_single(), which will grab memory from
|
||||
* the lowest available address range.
|
||||
*/
|
||||
ret = map_single(hwdev, NULL, size, DMA_FROM_DEVICE);
|
||||
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;
|
||||
}
|
||||
|
|
@ -597,6 +648,7 @@ swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size,
|
|||
{
|
||||
dma_addr_t dev_addr = swiotlb_virt_to_bus(ptr);
|
||||
void *map;
|
||||
struct swiotlb_phys_addr buffer;
|
||||
|
||||
BUG_ON(dir == DMA_NONE);
|
||||
/*
|
||||
|
|
@ -611,7 +663,9 @@ swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size,
|
|||
/*
|
||||
* Oh well, have to allocate and map a bounce buffer.
|
||||
*/
|
||||
map = map_single(hwdev, ptr, size, dir);
|
||||
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;
|
||||
|
|
@ -756,18 +810,20 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
|
|||
int dir, struct dma_attrs *attrs)
|
||||
{
|
||||
struct scatterlist *sg;
|
||||
void *addr;
|
||||
struct swiotlb_phys_addr buffer;
|
||||
dma_addr_t dev_addr;
|
||||
int i;
|
||||
|
||||
BUG_ON(dir == DMA_NONE);
|
||||
|
||||
for_each_sg(sgl, sg, nelems, i) {
|
||||
addr = SG_ENT_VIRT_ADDRESS(sg);
|
||||
dev_addr = swiotlb_virt_to_bus(addr);
|
||||
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 = map_single(hwdev, addr, sg->length, dir);
|
||||
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. */
|
||||
|
|
@ -807,11 +863,11 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
|
|||
BUG_ON(dir == DMA_NONE);
|
||||
|
||||
for_each_sg(sgl, sg, nelems, i) {
|
||||
if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
|
||||
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(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
|
||||
dma_mark_clean(swiotlb_bus_to_virt(sg->dma_address), sg->dma_length);
|
||||
}
|
||||
}
|
||||
EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
|
||||
|
|
@ -840,11 +896,11 @@ swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
|
|||
BUG_ON(dir == DMA_NONE);
|
||||
|
||||
for_each_sg(sgl, sg, nelems, i) {
|
||||
if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg))
|
||||
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(SG_ENT_VIRT_ADDRESS(sg), sg->dma_length);
|
||||
dma_mark_clean(swiotlb_bus_to_virt(sg->dma_address), sg->dma_length);
|
||||
}
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue