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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>
tags/2020-06-01
Alison Wang 5 years ago
committed by Albert ARIBAUD
parent
commit
53fd4b8c22
1 changed files with 1 additions and 1 deletions
  1. +1
    -1
      arch/arm/include/asm/system.h

+ 1
- 1
arch/arm/include/asm/system.h View File

@@ -194,7 +194,7 @@ void save_boot_params_ret(void);
static inline unsigned int get_cr(void)
{
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;
}