On Sat, Mar 19, 2005 at 04:17:51PM -0600, Matt Domsch wrote:
> OK, then how's this for review? Compiles clean, can't test it myself
> for a few days.
>
> - int high = 0, mmu;
> - if (((unsigned long)virt_to_bus(memory) + size) > 0xffffffffUL)
> - high = 1;
> - mmu = high;
> + int high = (((unsigned long)virt_to_bus(memory) + size) & ~dma_mask) != 0;
> + int mmu = high;
Documentation/DMA-mapping.txt says consistent DMA mapping interface will always
return SAC addressable DMA address. Your patch breaks this behavior.
(Though I don't know the reason why this behavior is expected!)
Appended is a simple 2.4 patch which will sync the behavior with 2.6
thanks,
suresh
--
Sync 2.4 pci_alloc_consistent behavior with 2.6
Signed-off-by: Suresh Siddha <[email protected]>
diff -Nru linux-2.4.29/arch/ia64/lib/swiotlb.c linux-2.4.29-swiotlb/arch/ia64/lib/swiotlb.c
--- linux-2.4.29/arch/ia64/lib/swiotlb.c 2003-08-25 04:44:39.000000000 -0700
+++ linux-2.4.29-swiotlb/arch/ia64/lib/swiotlb.c 2005-03-22 10:51:21.968565920 -0800
@@ -50,13 +50,13 @@
* 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;
+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 = 1024;
+static unsigned long io_tlb_nslabs = 32768;
/*
* This is a free list describing the number of free entries available from each index
diff -Nru linux-2.4.29/arch/x86_64/kernel/pci-gart.c linux-2.4.29-swiotlb/arch/x86_64/kernel/pci-gart.c
--- linux-2.4.29/arch/x86_64/kernel/pci-gart.c 2004-08-07 16:26:04.000000000 -0700
+++ linux-2.4.29-swiotlb/arch/x86_64/kernel/pci-gart.c 2005-03-22 10:38:45.211610464 -0800
@@ -155,7 +155,7 @@
int i;
unsigned long iommu_page;
- if (hwdev == NULL || hwdev->dma_mask < 0xffffffff || no_iommu)
+ if (hwdev == NULL || hwdev->dma_mask < 0xffffffff || (no_iommu && !swiotlb))
gfp |= GFP_DMA;
/*
@@ -174,6 +174,22 @@
if (force_mmu && !(gfp & GFP_DMA))
mmu = 1;
if (no_iommu) {
+#ifdef CONFIG_SWIOTLB
+ if (swiotlb && high && hwdev) {
+ unsigned long dma_mask = 0;
+ if (hwdev->dma_mask == ~0UL) {
+ hwdev->dma_mask = 0xffffffff;
+ dma_mask = ~0UL;
+ }
+ *dma_handle = swiotlb_map_single(hwdev, memory, size,
+ PCI_DMA_FROMDEVICE);
+ if (dma_mask)
+ hwdev->dma_mask = dma_mask;
+ memset(phys_to_virt(*dma_handle), 0, size);
+ free_pages((unsigned long)memory, get_order(size));
+ return phys_to_virt(*dma_handle);
+ }
+#endif
if (high) goto error;
mmu = 0;
}
@@ -218,8 +234,16 @@
void *vaddr, dma_addr_t bus)
{
unsigned long iommu_page;
-
+ extern char *io_tlb_start, *io_tlb_end;
+
size = round_up(size, PAGE_SIZE);
+#ifdef CONFIG_SWIOTLB
+ if (swiotlb && vaddr >= (void *)io_tlb_start &&
+ vaddr < (void *)io_tlb_end) {
+ swiotlb_unmap_single (hwdev, bus, size, PCI_DMA_TODEVICE);
+ return;
+ }
+#endif
if (bus >= iommu_bus_base && bus < iommu_bus_base + iommu_size) {
unsigned pages = size >> PAGE_SHIFT;
iommu_page = (bus - iommu_bus_base) >> PAGE_SHIFT;
-
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