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Diffstat (limited to 'arch/ia64/sn/pci/pci_dma.c')
-rw-r--r--arch/ia64/sn/pci/pci_dma.c46
1 files changed, 46 insertions, 0 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;