linux-kernel - [PATCH] x86: Unbreak early processor microcode loading

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Date:	Tue,  3 Mar 2015 23:10:44 +0800
From:	Daniel J Blueman <daniel@...ascale.com>
To:	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
	"H. Peter Anvin" <hpa@...or.com>
Cc:	Daniel J Blueman <daniel@...ascale.com>,
	Quentin Casasnovas <quentin.casasnovas@...cle.com>,
	Steffen Persvold <sp@...ascale.com>,
	linux-kernel@...r.kernel.org, x86@...nel.org
Subject: [PATCH] x86: Unbreak early processor microcode loading

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.

Signed-off-by: Daniel J Blueman <daniel@...ascale.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
 
 	ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev,
 						     refresh_fw);
-- 
2.1.0

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