[RFC 07/18] arm: mm: retry on QSD icache parity errors

[Ashwin Chaugule]

On Mon, Jan 11, 2010 at 5:47 PM, Daniel Walker <dwalker at codeaurora.org> wrote:
> From: Steve Muckle <smuckle at quicinc.com>
>

> +static int
> +do_imprecise_ext(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
> +{
> +#ifdef CONFIG_ARCH_MSM_SCORPION
> +       unsigned int regval;
> +       static unsigned char flush_toggle;
> +
> +       asm("mrc p15, 0, %0, c5, c1, 0\n" /* read adfsr for fault status */
> +           : "=r" (regval));
> +       if (regval == 0x2) {
> +               /* Fault was caused by icache parity error. Alternate
> +                * simply retrying the access and flushing the icache. */
> +               flush_toggle ^= 1;
> +               if (flush_toggle)
> +                       asm("mcr p15, 0, %0, c7, c5, 0\n"
> +                           :
> +                           : "r" (regval)); /* input value is ignored */

Wouldn't you need regval = 0 here, to clear the EFSR ?


> +               /* Clear fault in EFSR. */
> +               asm("mcr p15, 7, %0, c15, c0, 1\n"
> +                   :
> +                   : "r" (regval));
> +               /* Clear fault in ADFSR. */
> +               regval = 0;
> +               asm("mcr p15, 0, %0, c5, c1, 0\n"
> +                   :
> +                   : "r" (regval));
> +               return 0;
> +       }
> +#endif
> +