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-rw-r--r--lib/swiotlb.c255
1 files changed, 188 insertions, 67 deletions
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 5f6c629..fa2dc4e 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -21,9 +21,12 @@
#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>
@@ -36,22 +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))
-
-/*
- * 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))
/*
@@ -102,7 +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
@@ -126,6 +116,72 @@ setup_io_tlb_npages(char *str)
__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.
@@ -145,7 +201,7 @@ swiotlb_init_with_default_size(size_t default_size)
/*
* Get IO TLB memory from the low pages
*/
- io_tlb_start = alloc_bootmem_low_pages(bytes);
+ 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;
@@ -159,7 +215,7 @@ 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
@@ -168,8 +224,7 @@ swiotlb_init_with_default_size(size_t default_size)
if (!io_tlb_overflow_buffer)
panic("Cannot allocate SWIOTLB overflow buffer!\n");
- printk(KERN_INFO "Placing software IO TLB between 0x%lx - 0x%lx\n",
- virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));
+ swiotlb_print_info(bytes);
}
void __init
@@ -202,8 +257,7 @@ swiotlb_late_init_with_default_size(size_t default_size)
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
- io_tlb_start = (char *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
- order);
+ io_tlb_start = swiotlb_alloc(order, io_tlb_nslabs);
if (io_tlb_start)
break;
order--;
@@ -235,12 +289,12 @@ 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
@@ -250,9 +304,7 @@ swiotlb_late_init_with_default_size(size_t default_size)
if (!io_tlb_overflow_buffer)
goto cleanup4;
- printk(KERN_INFO "Placing %luMB software IO TLB between 0x%lx - "
- "0x%lx\n", bytes >> 20,
- virt_to_bus(io_tlb_start), virt_to_bus(io_tlb_end));
+ swiotlb_print_info(bytes);
return 0;
@@ -279,16 +331,69 @@ 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, 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;
@@ -298,11 +403,16 @@ 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 = virt_to_bus(io_tlb_start) & mask;
+ 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);
@@ -378,10 +488,15 @@ found:
* 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)
- memcpy(dma_addr, buffer, size);
+ __sync_single(buffer, dma_addr, size, DMA_TO_DEVICE);
return dma_addr;
}
@@ -395,17 +510,17 @@ 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;
- 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.
*/
- memcpy(buffer, dma_addr, size);
+ __sync_single(buffer, dma_addr, size, DMA_FROM_DEVICE);
/*
* Return the buffer to the free list by setting the corresponding
@@ -437,21 +552,18 @@ 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:
if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
- memcpy(buffer, dma_addr, size);
+ __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))
- memcpy(dma_addr, buffer, size);
+ __sync_single(buffer, dma_addr, size, DMA_TO_DEVICE);
else
BUG_ON(dir != DMA_FROM_DEVICE);
break;
@@ -473,7 +585,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_mask = hwdev->coherent_dma_mask;
ret = (void *)__get_free_pages(flags, order);
- if (ret && !is_buffer_dma_capable(dma_mask, virt_to_bus(ret), size)) {
+ 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().
@@ -488,13 +600,16 @@ 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;
}
memset(ret, 0, size);
- dev_addr = virt_to_bus(ret);
+ 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)) {
@@ -554,8 +669,9 @@ 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 = virt_to_bus(ptr);
+ dma_addr_t dev_addr = swiotlb_virt_to_bus(ptr);
void *map;
+ struct swiotlb_phys_addr buffer;
BUG_ON(dir == DMA_NONE);
/*
@@ -563,19 +679,22 @@ swiotlb_map_single_attrs(struct device *hwdev, void *ptr, size_t size,
* we can safely return the device addr and not worry about bounce
* buffering it.
*/
- if (!address_needs_mapping(hwdev, dev_addr, size) && !swiotlb_force)
+ 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.
*/
- 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;
}
- dev_addr = virt_to_bus(map);
+ dev_addr = swiotlb_virt_to_bus(map);
/*
* Ensure that the address returned is DMA'ble
@@ -605,7 +724,7 @@ 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 = bus_to_virt(dev_addr);
+ char *dma_addr = swiotlb_bus_to_virt(dev_addr);
BUG_ON(dir == DMA_NONE);
if (is_swiotlb_buffer(dma_addr))
@@ -635,7 +754,7 @@ static void
swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
size_t size, int dir, int target)
{
- char *dma_addr = bus_to_virt(dev_addr);
+ char *dma_addr = swiotlb_bus_to_virt(dev_addr);
BUG_ON(dir == DMA_NONE);
if (is_swiotlb_buffer(dma_addr))
@@ -666,7 +785,7 @@ 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 = bus_to_virt(dev_addr) + offset;
+ char *dma_addr = swiotlb_bus_to_virt(dev_addr) + offset;
BUG_ON(dir == DMA_NONE);
if (is_swiotlb_buffer(dma_addr))
@@ -714,18 +833,20 @@ 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 = virt_to_bus(addr);
- if (swiotlb_force ||
+ 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. */
@@ -735,7 +856,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
sgl[0].dma_length = 0;
return 0;
}
- sg->dma_address = virt_to_bus(map);
+ sg->dma_address = swiotlb_virt_to_bus(map);
} else
sg->dma_address = dev_addr;
sg->dma_length = sg->length;
@@ -765,11 +886,11 @@ 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))
- unmap_single(hwdev, bus_to_virt(sg->dma_address),
+ 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);
@@ -798,11 +919,11 @@ 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))
- sync_single(hwdev, bus_to_virt(sg->dma_address),
+ 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);
}
}
@@ -823,7 +944,7 @@ swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
int
swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
{
- return (dma_addr == virt_to_bus(io_tlb_overflow_buffer));
+ return (dma_addr == swiotlb_virt_to_bus(io_tlb_overflow_buffer));
}
/*
@@ -835,7 +956,7 @@ swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
int
swiotlb_dma_supported(struct device *hwdev, u64 mask)
{
- return virt_to_bus(io_tlb_end - 1) <= mask;
+ return swiotlb_virt_to_bus(io_tlb_end - 1) <= mask;
}
EXPORT_SYMBOL(swiotlb_map_single);
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