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>
This commit is contained in:
Russell King 2020-10-18 09:39:21 +01:00 committed by Greg Kroah-Hartman
parent b2640b08c4
commit 75be485249

View File

@ -66,15 +66,15 @@ 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;
}
@ -100,17 +100,17 @@ 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;