# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Date 1168616070 0
# Node ID ed73ff8440d8077fdd9b2e3cd93cd753a81d4021
# Parent 38fcc76469599d5c7f9c46b56e20f1dbfcaecd84
linux: Reduce restrictions on address width for DMA operations
Use address width needed by device rather than dma_bits in
dma_alloc_coherent().
Probe supported address width in swiotlb initialization.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---
linux-2.6-xen-sparse/arch/i386/kernel/pci-dma-xen.c | 9 +
linux-2.6-xen-sparse/arch/i386/kernel/swiotlb.c | 60 +++++++----
linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/swiotlb.h | 2
3 files changed, 51 insertions(+), 20 deletions(-)
diff -r 38fcc7646959 -r ed73ff8440d8
linux-2.6-xen-sparse/arch/i386/kernel/pci-dma-xen.c
--- a/linux-2.6-xen-sparse/arch/i386/kernel/pci-dma-xen.c Fri Jan 12
15:27:09 2007 +0000
+++ b/linux-2.6-xen-sparse/arch/i386/kernel/pci-dma-xen.c Fri Jan 12
15:34:30 2007 +0000
@@ -161,6 +161,8 @@ void *dma_alloc_coherent(struct device *
struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
unsigned int order = get_order(size);
unsigned long vstart;
+ u64 mask;
+
/* ignore region specifiers */
gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
@@ -183,9 +185,14 @@ void *dma_alloc_coherent(struct device *
vstart = __get_free_pages(gfp, order);
ret = (void *)vstart;
+ if (dev != NULL && dev->coherent_dma_mask)
+ mask = dev->coherent_dma_mask;
+ else
+ mask = 0xffffffff;
+
if (ret != NULL) {
if (xen_create_contiguous_region(vstart, order,
- dma_bits) != 0) {
+ fls64(mask)) != 0) {
free_pages(vstart, order);
return NULL;
}
diff -r 38fcc7646959 -r ed73ff8440d8
linux-2.6-xen-sparse/arch/i386/kernel/swiotlb.c
--- a/linux-2.6-xen-sparse/arch/i386/kernel/swiotlb.c Fri Jan 12 15:27:09
2007 +0000
+++ b/linux-2.6-xen-sparse/arch/i386/kernel/swiotlb.c Fri Jan 12 15:34:30
2007 +0000
@@ -47,9 +47,6 @@ EXPORT_SYMBOL(swiotlb);
*/
#define IO_TLB_SHIFT 11
-/* Width of DMA addresses. 30 bits is a b44 limitation. */
-#define DEFAULT_DMA_BITS 30
-
static int swiotlb_force;
static char *iotlb_virt_start;
static unsigned long iotlb_nslabs;
@@ -98,11 +95,12 @@ static struct phys_addr {
*/
static DEFINE_SPINLOCK(io_tlb_lock);
-unsigned int dma_bits = DEFAULT_DMA_BITS;
+static unsigned int dma_bits;
+static unsigned int __initdata max_dma_bits = 32;
static int __init
setup_dma_bits(char *str)
{
- dma_bits = simple_strtoul(str, NULL, 0);
+ max_dma_bits = simple_strtoul(str, NULL, 0);
return 0;
}
__setup("dma_bits=", setup_dma_bits);
@@ -143,6 +141,7 @@ swiotlb_init_with_default_size (size_t d
swiotlb_init_with_default_size (size_t default_size)
{
unsigned long i, bytes;
+ int rc;
if (!iotlb_nslabs) {
iotlb_nslabs = (default_size >> IO_TLB_SHIFT);
@@ -159,16 +158,33 @@ swiotlb_init_with_default_size (size_t d
*/
iotlb_virt_start = alloc_bootmem_low_pages(bytes);
if (!iotlb_virt_start)
- panic("Cannot allocate SWIOTLB buffer!\n"
- "Use dom0_mem Xen boot parameter to reserve\n"
- "some DMA memory (e.g., dom0_mem=-128M).\n");
-
+ panic("Cannot allocate SWIOTLB buffer!\n");
+
+ dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT;
for (i = 0; i < iotlb_nslabs; i += IO_TLB_SEGSIZE) {
- int rc = xen_create_contiguous_region(
- (unsigned long)iotlb_virt_start + (i << IO_TLB_SHIFT),
- get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT),
- dma_bits);
- BUG_ON(rc);
+ do {
+ rc = xen_create_contiguous_region(
+ (unsigned long)iotlb_virt_start + (i <<
IO_TLB_SHIFT),
+ get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT),
+ dma_bits);
+ } while (rc && dma_bits++ < max_dma_bits);
+ if (rc) {
+ if (i == 0)
+ panic("No suitable physical memory available
for SWIOTLB buffer!\n"
+ "Use dom0_mem Xen boot parameter to
reserve\n"
+ "some DMA memory (e.g.,
dom0_mem=-128M).\n");
+ iotlb_nslabs = i;
+ i <<= IO_TLB_SHIFT;
+ free_bootmem(__pa(iotlb_virt_start + i), bytes - i);
+ bytes = i;
+ for (dma_bits = 0; i > 0; i -= IO_TLB_SEGSIZE <<
IO_TLB_SHIFT) {
+ unsigned int bits =
fls64(virt_to_bus(iotlb_virt_start + i - 1));
+
+ if (bits > dma_bits)
+ dma_bits = bits;
+ }
+ break;
+ }
}
/*
@@ -186,17 +202,27 @@ swiotlb_init_with_default_size (size_t d
* 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");
+
+ do {
+ rc = xen_create_contiguous_region(
+ (unsigned long)io_tlb_overflow_buffer,
+ get_order(io_tlb_overflow),
+ dma_bits);
+ } while (rc && dma_bits++ < max_dma_bits);
+ if (rc)
+ panic("No suitable physical memory available for SWIOTLB
overflow buffer!\n");
iotlb_pfn_start = __pa(iotlb_virt_start) >> PAGE_SHIFT;
iotlb_pfn_end = iotlb_pfn_start + (bytes >> PAGE_SHIFT);
printk(KERN_INFO "Software IO TLB enabled: \n"
" Aperture: %lu megabytes\n"
- " Kernel range: 0x%016lx - 0x%016lx\n"
+ " Kernel range: %p - %p\n"
" Address size: %u bits\n",
bytes >> 20,
- (unsigned long)iotlb_virt_start,
- (unsigned long)iotlb_virt_start + bytes,
+ iotlb_virt_start, iotlb_virt_start + bytes,
dma_bits);
}
diff -r 38fcc7646959 -r ed73ff8440d8
linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/swiotlb.h
--- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/swiotlb.h Fri Jan
12 15:27:09 2007 +0000
+++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/swiotlb.h Fri Jan
12 15:34:30 2007 +0000
@@ -34,8 +34,6 @@ extern int swiotlb_dma_supported(struct
extern int swiotlb_dma_supported(struct device *hwdev, u64 mask);
extern void swiotlb_init(void);
-extern unsigned int dma_bits;
-
#ifdef CONFIG_SWIOTLB
extern int swiotlb;
#else
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