Hi,
Here is a patch to fix cache coherency when doing I/O on the
O2. It simply adds writeback and invalidate when unmapping DMA
memory. This fixes coherency when reading from a device. It
also adds support for mapping/unmapping pages for both the IP27 and
the O2.
Vivien Chappelier.
diff -Naur linux/arch/mips64/sgi-ip27/ip27-pci-dma.c linux.patch/arch/mips64/sgi-ip27/ip27-pci-dma.c
--- linux/arch/mips64/sgi-ip27/ip27-pci-dma.c Sun Dec 9 15:47:15 2001
+++ linux.patch/arch/mips64/sgi-ip27/ip27-pci-dma.c Fri Dec 21 11:08:22 2001
@@ -112,7 +112,11 @@
/* Make sure that gcc doesn't leave the empty loop body. */
for (i = 0; i < nents; i++, sg++) {
- sg->address = (char *)(bus_to_baddr[hwdev->bus->number] | __pa(sg->address));
+ if(sg->address)
+ address = sg->address;
+ else
+ address = page_address(sg->page) + sg->offset;
+ sg->dvma_address = (char *)(bus_to_baddr[hwdev->bus->number] | __pa(address));
}
return nents;
diff -Naur linux/arch/mips64/sgi-ip32/ip32-pci-dma.c linux.patch/arch/mips64/sgi-ip32/ip32-pci-dma.c
--- linux/arch/mips64/sgi-ip32/ip32-pci-dma.c Sun Dec 9 15:47:15 2001
+++ linux.patch/arch/mips64/sgi-ip32/ip32-pci-dma.c Fri Dec 21 11:07:33 2001
@@ -99,7 +99,10 @@
if (direction == PCI_DMA_NONE)
BUG();
DPRINTK("pci_unmap_single\n");
- /* Nothing to do */
+ if (direction != PCI_DMA_TODEVICE) {
+ mips_wbflush();
+ dma_cache_wback_inv((unsigned long)__va(dma_addr), size);
+ }
}
/*
@@ -122,6 +125,7 @@
int nents, int direction)
{
int i;
+ unsigned long address;
if (direction == PCI_DMA_NONE)
BUG();
@@ -131,9 +135,13 @@
DPRINTK("pci_map_sg\n");
/* Make sure that gcc doesn't leave the empty loop body. */
for (i = 0; i < nents; i++, sg++) {
+ if(sg->address)
+ address = sg->address;
+ else
+ address = page_address(sg->page) + sg->offset;
mips_wbflush();
- dma_cache_wback_inv((unsigned long)sg->address, sg->length);
- sg->address = (char *)(__pa(sg->address));
+ dma_cache_wback_inv(address, sg->length);
+ sg->dvma_address = __pa(address);
}
return nents;
@@ -147,10 +155,22 @@
void pci_unmap_sg(struct pci_dev *hwdev, struct scatterlist *sg,
int nents, int direction)
{
+ int i;
+ unsigned long address;
+
if (direction == PCI_DMA_NONE)
BUG();
DPRINTK("pci_unmap_sg\n");
- /* Nothing to do */
+ for (i = 0; i < nents; i++, sg++) {
+ if (direction != PCI_DMA_TODEVICE) {
+ if(sg->address)
+ address = sg->address;
+ else
+ address = page_address(sg->page) + sg->offset;
+ mips_wbflush();
+ dma_cache_wback_inv(address, sg->length);
+ }
+ }
}
/*
@@ -188,13 +208,19 @@
int nelems, int direction)
{
int i;
+ unsigned long address;
+
if (direction == PCI_DMA_NONE)
BUG();
DPRINTK("pci_dma_sync_sg\n");
/* Make sure that gcc doesn't leave the empty loop body. */
for (i = 0; i < nelems; i++, sg++){
+ if(sg->address)
+ address = sg->address;
+ else
+ address = page_address(sg->page) + sg->offset;
mips_wbflush();
- dma_cache_wback_inv((unsigned long)__va(sg->address), sg->length);
+ dma_cache_wback_inv(address, sg->length);
}
/* if(direction==PCI_DMA_TODEVICE)
mace_inv_read_buffers();*/
diff -Naur linux/include/asm-mips64/mipsregs.h linux.patch/include/asm-mips64/mipsregs.h
--- linux/include/asm-mips64/mipsregs.h Sun Dec 9 15:52:27 2001
+++ linux.patch/include/asm-mips64/mipsregs.h Fri Dec 21 11:28:06 2001
@@ -367,6 +367,7 @@
#define CONF_CM_CMASK 7
#define CONF_DB (1 << 4)
#define CONF_IB (1 << 5)
+#define CONF_SE (1 << 12)
#define CONF_SC (1 << 17)
#define CONF_AC (1 << 23)
#define CONF_HALT (1 << 25)
diff -Naur linux/include/asm-mips64/pci.h linux.patch/include/asm-mips64/pci.h
--- linux/include/asm-mips64/pci.h Thu Dec 20 18:32:18 2001
+++ linux.patch/include/asm-mips64/pci.h Fri Dec 21 11:10:08 2001
@@ -319,7 +319,7 @@
* returns, or alternatively stop on the first sg_dma_len(sg) which
* is 0.
*/
-#define sg_dma_address(sg) ((unsigned long)((sg)->address))
+#define sg_dma_address(sg) ((sg)->dvma_address)
#define sg_dma_len(sg) ((sg)->length)
#endif /* __KERNEL__ */
diff -Naur linux/include/asm-mips64/pgtable.h linux.patch/include/asm-mips64/pgtable.h
--- linux/include/asm-mips64/pgtable.h Thu Dec 20 18:32:18 2001
+++ linux.patch/include/asm-mips64/pgtable.h Thu Dec 20 20:03:07 2001
@@ -180,11 +180,11 @@
#ifdef CONFIG_MIPS_UNCACHED
#define PAGE_CACHABLE_DEFAULT _CACHE_UNCACHED
#else /* ! UNCACHED */
-#ifdef CONFIG_SGI_IP22
+#if defined(CONFIG_SGI_IP22) || defined(CONFIG_SGI_IP32)
#define PAGE_CACHABLE_DEFAULT _CACHE_CACHABLE_NONCOHERENT
-#else /* ! IP22 */
+#else /* ! (IP22 || IP32)*/
#define PAGE_CACHABLE_DEFAULT _CACHE_CACHABLE_COW
-#endif /* IP22 */
+#endif /* (IP22 || IP32) */
#endif /* UNCACHED */
#define PAGE_NONE __pgprot(_PAGE_PRESENT | PAGE_CACHABLE_DEFAULT)
diff -Naur linux/include/asm-mips64/scatterlist.h linux.patch/include/asm-mips64/scatterlist.h
--- linux/include/asm-mips64/scatterlist.h Thu Dec 20 18:32:18 2001
+++ linux.patch/include/asm-mips64/scatterlist.h Fri Dec 21 11:09:40 2001
@@ -7,7 +7,7 @@
unsigned int offset;
unsigned int length;
- __u32 dvma_address;
+ dma_addr_t dvma_address;
};
struct mmu_sglist {
