On 05/16/2018 04:00 AM, Russell King wrote:
> Check for CPU bugs when secondary processors are being brought online,
> and also when CPUs are resuming from a low power mode. This gives an
> opportunity to check that processor specific bug workarounds are
> correctly enabled for all paths that a CPU re-enters the kernel.
>
> Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---
> arch/arm/include/asm/bugs.h | 2 ++
> arch/arm/kernel/bugs.c | 5 +++++
> arch/arm/kernel/smp.c | 4 ++++
> arch/arm/kernel/suspend.c | 2 ++
> 4 files changed, 13 insertions(+)
>
> diff --git a/arch/arm/include/asm/bugs.h b/arch/arm/include/asm/bugs.h
> index ed122d294f3f..73a99c72a930 100644
> --- a/arch/arm/include/asm/bugs.h
> +++ b/arch/arm/include/asm/bugs.h
> @@ -14,8 +14,10 @@ extern void check_writebuffer_bugs(void);
>
> #ifdef CONFIG_MMU
> extern void check_bugs(void);
> +extern void check_other_bugs(void);
> #else
> #define check_bugs() do { } while (0)
> +#define check_other_bugs() do { } while (0)
> #endif
>
> #endif
> diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c
> index 88024028bb70..16e7ba2a9cc4 100644
> --- a/arch/arm/kernel/bugs.c
> +++ b/arch/arm/kernel/bugs.c
> @@ -3,7 +3,12 @@
> #include <asm/bugs.h>
> #include <asm/proc-fns.h>
>
> +void check_other_bugs(void)
> +{
> +}
> +
> void __init check_bugs(void)
> {
> check_writebuffer_bugs();
> + check_other_bugs();
> }
> diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
> index 2da087926ebe..5ad0b67b9e33 100644
> --- a/arch/arm/kernel/smp.c
> +++ b/arch/arm/kernel/smp.c
> @@ -31,6 +31,7 @@
> #include <linux/irq_work.h>
>
> #include <linux/atomic.h>
> +#include <asm/bugs.h>
> #include <asm/smp.h>
> #include <asm/cacheflush.h>
> #include <asm/cpu.h>
> @@ -405,6 +406,9 @@ asmlinkage void secondary_start_kernel(void)
> * before we continue - which happens after __cpu_up returns.
> */
> set_cpu_online(cpu, true);
> +
> + check_other_bugs();
Given what is currently implemented, I don't think the location of
check_other_bugs() matters too much, but we might have to move this
after the local_irq_enable() at some point if we need to check for e.g:
a bogus local timer or whatever?
--
Florian
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