Re: [PATCH] x86: fix: do not run code in amd_bus.c on non-AMD CPUs

From: Yinghai Lu
Date: Fri Aug 22 2008 - 14:48:01 EST


On Fri, Aug 22, 2008 at 11:23 AM, Robert Richter <robert.richter@xxxxxxx> wrote:
> On 21.08.08 13:59:33, Jan Beulich wrote:
>> Even worse - this would even try to access the MSR on non-AMD CPUs
>> (currently probably prevented just by the fact that only AMD ones use
>> family values of 0x10 or higher).
>
> This patch adds cpu vendor check to the postcore_initcalls.
>
> Cc: Jan Beulich <jbeulich@xxxxxxxxxx>
> Cc: Yinghai Lu <yhlu.kernel@xxxxxxxxx>
> Signed-off-by: Robert Richter <robert.richter@xxxxxxx>
> ---
> arch/x86/pci/amd_bus.c | 19 ++++++++++++++++---
> 1 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/pci/amd_bus.c b/arch/x86/pci/amd_bus.c
> index dbf5323..4a6f1a6 100644
> --- a/arch/x86/pci/amd_bus.c
> +++ b/arch/x86/pci/amd_bus.c
> @@ -555,9 +555,11 @@ static int __init early_fill_mp_bus_info(void)
> return 0;
> }
>
> -postcore_initcall(early_fill_mp_bus_info);
> +#else /* !CONFIG_X86_64 */
>
> -#endif
> +static int __init early_fill_mp_bus_info(void) { return 0; }
> +
> +#endif /* !CONFIG_X86_64 */
>
> /* common 32/64 bit code */
>
> @@ -583,4 +585,15 @@ static int __init enable_pci_io_ecs(void)
> return 0;
> }
>
> -postcore_initcall(enable_pci_io_ecs);
> +static int __init amd_postcore_init(void)
> +{
> + if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
> + return 0;
> +
> + early_fill_mp_bus_info();
> + enable_pci_io_ecs();
> +
> + return 0;
> +}
> +
> +postcore_initcall(amd_postcore_init);

1. early_fill_mp_bus_info has checking with vendor/deviceid in itself.

2. you didn't address: when cpu is hot plug in later,
enable_pci_to_ecs_per_cpu will not be called.
( maxcpus and addtional_cpus)

YH
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