arm: mmu: Add missing volatile for reading SCTLR register

Add 'volatile' qualifier to the asm statement in get_cr()
so that the statement is not optimized out by the compiler.

(http://comments.gmane.org/gmane.linux.linaro.toolchain/5163)

Without the 'volatile', get_cr() returns a wrong value which
prevents enabling the MMU  and later causes a PCIE VA access
failure.

Signed-off-by: Alison Wang <alison.wang@freescale.com>
This commit is contained in:
Alison Wang 2015-09-09 10:22:02 +08:00 committed by Albert ARIBAUD
parent 1275456d31
commit 53fd4b8c22

View file

@ -194,7 +194,7 @@ void save_boot_params_ret(void);
static inline unsigned int get_cr(void) static inline unsigned int get_cr(void)
{ {
unsigned int val; unsigned int val;
asm("mrc p15, 0, %0, c1, c0, 0 @ get CR" : "=r" (val) : : "cc"); asm volatile("mrc p15, 0, %0, c1, c0, 0 @ get CR" : "=r" (val) : : "cc");
return val; return val;
} }