[POWERPC] iSeries: eliminate pci_dn bussubno

xlate_iomm_address() really wants the ds_addr to pass to the HV, so store
that value (instead of the BAR number) when we allocate the device bars.
This is not a fast path, so we can look up the device_node property
there instead of using the bussubno field of the pci_dn.

The other user of iseries_ds_addr() was already scanning the device tree,
so looking up a property will not slow it down any more.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 7 insertions, 5 deletions

diff --git a/arch/powerpc/platforms/iseries/pci.c b/arch/powerpc/platforms/iseries/pci.c
index 931941036b91..cc562e4c2f32 100644
--- a/arch/powerpc/platforms/iseries/pci.c
+++ b/arch/powerpc/platforms/iseries/pci.c
@@ -29,6 +29,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/of.h>
 
 #include <asm/types.h>
 #include <asm/io.h>
@@ -70,7 +71,7 @@ static long current_iomm_table_entry;
  * Lookup Tables.
  */
 static struct device_node *iomm_table[IOMM_TABLE_MAX_ENTRIES];
-static u8 iobar_table[IOMM_TABLE_MAX_ENTRIES];
+static u64 ds_addr_table[IOMM_TABLE_MAX_ENTRIES];
 
 static DEFINE_SPINLOCK(iomm_table_lock);
 
@@ -80,8 +81,9 @@ static DEFINE_SPINLOCK(iomm_table_lock);
 static inline u64 iseries_ds_addr(struct device_node *node)
 {
         struct pci_dn *pdn = PCI_DN(node);
+        const u32 *sbp = of_get_property(node, "linux,subbus", NULL);
 
-        return ((u64)pdn->busno << 48) + ((u64)pdn->bussubno << 40)
+        return ((u64)pdn->busno << 48) + ((u64)(sbp ? *sbp : 0) << 40)
                         + ((u64)0x10 << 32);
 }
 
@@ -333,7 +335,8 @@ static void __init iomm_table_allocate_entry(struct pci_dev *dev, int bar_num)
          */
         while (bar_size > 0 ) {
                 iomm_table[current_iomm_table_entry] = dev->sysdata;
-                iobar_table[current_iomm_table_entry] = bar_num;
+                ds_addr_table[current_iomm_table_entry] =
+                        iseries_ds_addr(dev->sysdata) | (bar_num << 24);
                 bar_size -= IOMM_TABLE_ENTRY_SIZE;
                 ++current_iomm_table_entry;
         }
@@ -598,8 +601,7 @@ static inline struct device_node *xlate_iomm_address(
         dn = iomm_table[ind];
 
         if (dn != NULL) {
-                int barnum = iobar_table[ind];
-                *dsaptr = iseries_ds_addr(dn) | (barnum << 24);
+                *dsaptr = ds_addr_table[ind];
                 *bar_offset = base_addr % IOMM_TABLE_ENTRY_SIZE;
         } else
                 panic("PCI: Invalid PCI IO address detected!\n");