ARM: footbridge: fix dc21285 PCI configuration accessors

commit 39d3454c3513840eb123b3913fda6903e45ce671 upstream.

Building with gcc 4.9.2 reveals a latent bug in the PCI accessors
for Footbridge platforms, which causes a fatal alignment fault
while accessing IO memory. Fix this by making the assembly volatile.

Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/mach-footbridge/dc21285.c b/arch/arm/mach-footbridge/dc21285.c
index 416462e..f9713dc 100644 (file)
--- a/arch/arm/mach-footbridge/dc21285.c
+++ b/arch/arm/mach-footbridge/dc21285.c
@@ -65,15 +65,15 @@ dc21285_read_config(struct pci_bus *bus, unsigned int devfn, int where,
        if (addr)
                switch (size) {
                case 1:
-                       asm("ldrb       %0, [%1, %2]"
+                       asm volatile("ldrb      %0, [%1, %2]"
                                : "=r" (v) : "r" (addr), "r" (where) : "cc");
                        break;
                case 2:
-                       asm("ldrh       %0, [%1, %2]"
+                       asm volatile("ldrh      %0, [%1, %2]"
                                : "=r" (v) : "r" (addr), "r" (where) : "cc");
                        break;
                case 4:
-                       asm("ldr        %0, [%1, %2]"
+                       asm volatile("ldr       %0, [%1, %2]"
                                : "=r" (v) : "r" (addr), "r" (where) : "cc");
                        break;
                }
@@ -99,17 +99,17 @@ dc21285_write_config(struct pci_bus *bus, unsigned int devfn, int where,
        if (addr)
                switch (size) {
                case 1:
-                       asm("strb       %0, [%1, %2]"
+                       asm volatile("strb      %0, [%1, %2]"
                                : : "r" (value), "r" (addr), "r" (where)
                                : "cc");
                        break;
                case 2:
-                       asm("strh       %0, [%1, %2]"
+                       asm volatile("strh      %0, [%1, %2]"
                                : : "r" (value), "r" (addr), "r" (where)
                                : "cc");
                        break;
                case 4:
-                       asm("str        %0, [%1, %2]"
+                       asm volatile("str       %0, [%1, %2]"
                                : : "r" (value), "r" (addr), "r" (where)
                                : "cc");
                        break;