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-rw-r--r--arch/ia64/sn/pci/pci_dma.c46
-rw-r--r--include/asm-ia64/sn/sn_sal.h2
2 files changed, 47 insertions, 1 deletions
diff --git a/arch/ia64/sn/pci/pci_dma.c b/arch/ia64/sn/pci/pci_dma.c
index 0e4b9ad9ef0..abdf6eea6ac 100644
--- a/arch/ia64/sn/pci/pci_dma.c
+++ b/arch/ia64/sn/pci/pci_dma.c
@@ -326,6 +326,29 @@ int sn_pci_legacy_read(struct pci_bus *bus, u16 port, u32 *val, u8 size)
{
unsigned long addr;
int ret;
+ struct ia64_sal_retval isrv;
+
+ /*
+ * First, try the SN_SAL_IOIF_PCI_SAFE SAL call which can work
+ * around hw issues at the pci bus level. SGI proms older than
+ * 4.10 don't implment this.
+ */
+
+ SAL_CALL(isrv, SN_SAL_IOIF_PCI_SAFE,
+ pci_domain_nr(bus), bus->number,
+ 0, /* io */
+ 0, /* read */
+ port, size, __pa(val));
+
+ if (isrv.status == 0)
+ return size;
+
+ /*
+ * If the above failed, retry using the SAL_PROBE call which should
+ * be present in all proms (but which cannot work round PCI chipset
+ * bugs). This code is retained for compatability with old
+ * pre-4.10 proms, and should be removed at some point in the future.
+ */
if (!SN_PCIBUS_BUSSOFT(bus))
return -ENODEV;
@@ -349,6 +372,29 @@ int sn_pci_legacy_write(struct pci_bus *bus, u16 port, u32 val, u8 size)
int ret = size;
unsigned long paddr;
unsigned long *addr;
+ struct ia64_sal_retval isrv;
+
+ /*
+ * First, try the SN_SAL_IOIF_PCI_SAFE SAL call which can work
+ * around hw issues at the pci bus level. SGI proms older than
+ * 4.10 don't implment this.
+ */
+
+ SAL_CALL(isrv, SN_SAL_IOIF_PCI_SAFE,
+ pci_domain_nr(bus), bus->number,
+ 0, /* io */
+ 1, /* write */
+ port, size, __pa(&val));
+
+ if (isrv.status == 0)
+ return size;
+
+ /*
+ * If the above failed, retry using the SAL_PROBE call which should
+ * be present in all proms (but which cannot work round PCI chipset
+ * bugs). This code is retained for compatability with old
+ * pre-4.10 proms, and should be removed at some point in the future.
+ */
if (!SN_PCIBUS_BUSSOFT(bus)) {
ret = -ENODEV;
diff --git a/include/asm-ia64/sn/sn_sal.h b/include/asm-ia64/sn/sn_sal.h
index 34f3127e441..92df48a0412 100644
--- a/include/asm-ia64/sn/sn_sal.h
+++ b/include/asm-ia64/sn/sn_sal.h
@@ -68,7 +68,7 @@
#define SN_SAL_IOIF_INTERRUPT 0x0200004a
#define SN_SAL_HWPERF_OP 0x02000050 // lock
#define SN_SAL_IOIF_ERROR_INTERRUPT 0x02000051
-
+#define SN_SAL_IOIF_PCI_SAFE 0x02000052
#define SN_SAL_IOIF_SLOT_ENABLE 0x02000053
#define SN_SAL_IOIF_SLOT_DISABLE 0x02000054
#define SN_SAL_IOIF_GET_HUBDEV_INFO 0x02000055