Hi Stephen,
On Thu, 2011-02-24 at 18:44 +0000, Stephen Boyd wrote:
> We don't want the compiler to remove these asm statements or
> reorder them in any way. Mark them as volatile to be sure.
>
> Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> ---
> arch/arm/mach-msm/scm.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mach-msm/scm.c b/arch/arm/mach-msm/scm.c
> index f4b9bc9..ba57b5a 100644
> --- a/arch/arm/mach-msm/scm.c
> +++ b/arch/arm/mach-msm/scm.c
> @@ -174,7 +174,7 @@ static u32 smc(u32 cmd_addr)
> register u32 r0 asm("r0") = 1;
> register u32 r1 asm("r1") = (u32)&context_id;
> register u32 r2 asm("r2") = cmd_addr;
> - asm(
> + asm volatile(
> __asmeq("%0", "r0")
> __asmeq("%1", "r0")
> __asmeq("%2", "r1")
> @@ -271,7 +271,7 @@ u32 scm_get_version(void)
> return version;
>
> mutex_lock(&scm_lock);
> - asm(
> + asm volatile(
> __asmeq("%0", "r1")
> __asmeq("%1", "r0")
> __asmeq("%2", "r1")
These asm blocks all have sensible looking output constraints. Why
do they need to be marked volatile?
Will
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