linux-kernel - [PATCH v5 07/20] x86/mce: Reorder __mcheck_cpu_init

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Message-ID: <20250825-wip-mca-updates-v5-7-865768a2eef8@amd.com>
Date: Mon, 25 Aug 2025 17:33:04 +0000
From: Yazen Ghannam <yazen.ghannam@....com>
To: <x86@...nel.org>, Tony Luck <tony.luck@...el.com>, "Rafael J. Wysocki"
	<rafael@...nel.org>
CC: <linux-kernel@...r.kernel.org>, <linux-edac@...r.kernel.org>,
	<Smita.KoralahalliChannabasappa@....com>, Qiuxu Zhuo <qiuxu.zhuo@...el.com>,
	Nikolay Borisov <nik.borisov@...e.com>, <linux-acpi@...r.kernel.org>, "Yazen
 Ghannam" <yazen.ghannam@....com>
Subject: [PATCH v5 07/20] x86/mce: Reorder __mcheck_cpu_init_generic() call

Move __mcheck_cpu_init_generic() after __mcheck_cpu_init_prepare_banks()
so that MCA is enabled after the first MCA polling event.

This brings the MCA init flow closer to what is described in the x86 docs.

The AMD PPRs say
  "The operating system must initialize the MCA_CONFIG registers prior
  to initialization of the MCA_CTL registers.

  The MCA_CTL registers must be initialized prior to enabling the error
  reporting banks in MCG_CTL".

However, the Intel SDM "Machine-Check Initialization Pseudocode" says
MCG_CTL first then MCi_CTL.

But both agree that CR4.MCE should be set last.

Signed-off-by: Yazen Ghannam <yazen.ghannam@....com>
---

Notes:
    Link:
    https://lore.kernel.org/r/52a37afe-c41b-4f20-bbdc-bddc3ae26260@suse.com
    
    v4->v5:
    * New in v5.

 arch/x86/kernel/cpu/mce/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 0326fbb83adc..9cbf9e8c8060 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -2272,9 +2272,9 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
 
 	mca_cfg.initialized = 1;
 
-	__mcheck_cpu_init_generic();
 	__mcheck_cpu_init_vendor(c);
 	__mcheck_cpu_init_prepare_banks();
+	__mcheck_cpu_init_generic();
 	__mcheck_cpu_setup_timer();
 }
 
@@ -2440,9 +2440,9 @@ static void mce_syscore_shutdown(void)
  */
 static void mce_syscore_resume(void)
 {
-	__mcheck_cpu_init_generic();
 	__mcheck_cpu_init_vendor(raw_cpu_ptr(&cpu_info));
 	__mcheck_cpu_init_prepare_banks();
+	__mcheck_cpu_init_generic();
 }
 
 static struct syscore_ops mce_syscore_ops = {
@@ -2459,8 +2459,8 @@ static void mce_cpu_restart(void *data)
 {
 	if (!mce_available(raw_cpu_ptr(&cpu_info)))
 		return;
-	__mcheck_cpu_init_generic();
 	__mcheck_cpu_init_prepare_banks();
+	__mcheck_cpu_init_generic();
 	__mcheck_cpu_init_timer();
 }
 

-- 
2.51.0