[MODERATED] Re: [PATCH v5 02/11] TAAv5 2

[Borislav Petkov <bp@suse.de>]

On Fri, Oct 04, 2019 at 11:27:31PM -0700, speck for Pawan Gupta wrote:
> Move IA32_ARCH_CAPABILITIES MSR read to a helper function. If the CPU
> doesn't support this MSR return 0. Use this function in following
> commits to read IA32_ARCH_CAPABILITIES MSR.
> 
> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
> Reviewed-by: Mark Gross <mgross@linux.intel.com>
> Reviewed-by: Tony Luck <tony.luck@intel.com>
> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
> ---
>  arch/x86/kernel/cpu/common.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index f125bf7ecb6f..af9e357b2ca9 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -1091,19 +1091,27 @@ static bool __init cpu_matches(unsigned long which)
>  	return m && !!(m->driver_data & which);
>  }
>  
> -static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
> +u64 read_ia32_arch_cap(void)

If this is going to be used by other compilation units, call it
something more presentable and clear, with a proper prefix:

	x86_read_arch_cap_msr()

or so.

>  {
>  	u64 ia32_cap = 0;
>  
> +	/* Leave the MSR set to all 0's when not supported */

This comment is not really needed.

> +	if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES))
> +		rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
> +
> +	return ia32_cap;
> +}
> +
> +static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
		^^^^^^

Please audit your newly added functions whether they can be __init
too.

Thx.

-- 
Regards/Gruss,
    Boris.

SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 247165, AG München
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