[PATCH 5.10 096/120] ARM: footbridge: fix dc21285 PCI configuration accessors

Greg Kroah-Hartman
2021-02-08T17:37:06Z

From: Russell King <rmk+kernel@armlinux.org.uk>

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>
---
arch/arm/mach-footbridge/dc21285.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- 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,
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
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;