lkml.org 
[lkml]   [2015]   [Mar]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86: Unbreak early processor microcode loading
On Tue, Mar 03, 2015 at 11:10:44PM +0800, Daniel J Blueman wrote:
> The changes in 871b72dd "x86: microcode: use smp_call_function_single instead
> of set_cpus_allowed, cleanup of synchronization logic" introduced a check
> that prevents built-in microcode from being loaded before init starts.
>
> Conditionalise it on early microcode loading, so we get the expected behaviour
> when early microcode loading is enabled, and when it is not. This has potential
> importance as BIOSes often don't load the current microcode.

... probably because they don't have it. Which is also the main reason
for the existence of this microcode loader btw :)

>
> Signed-off-by: Daniel J Blueman <daniel@numascale.com>
> ---
> arch/x86/kernel/cpu/microcode/core.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
> index 36a8361..fa7f9fc 100644
> --- a/arch/x86/kernel/cpu/microcode/core.c
> +++ b/arch/x86/kernel/cpu/microcode/core.c
> @@ -391,9 +391,11 @@ static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
> if (collect_cpu_info(cpu))
> return UCODE_ERROR;
>
> +#if !defined(CONFIG_MICROCODE_AMD_EARLY) && !defined(CONFIG_MICROCODE_INTEL_EARLY)
> /* --dimm. Trigger a delayed update? */
> if (system_state != SYSTEM_RUNNING)
> return UCODE_NFOUND;
> +#endif

Ok, let me try to understand this correctly: where is this microcode
built in, into the kernel?

If yes, you should consider enabling the early loading
method and build in the microcode into the initrd, see
Documentation/x86/early-microcode.txt

This is the preferred method as we're applying the microcode much
earlier.

Back to you.

--
Regards/Gruss,
Boris.

ECO tip #101: Trim your mails when you reply.
--


\
 
 \ /
  Last update: 2015-03-03 18:01    [W:0.111 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site