linux-kernel - [PATCH] x86, ucode-amd: Move family check to microcde

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Date:	Tue, 17 Nov 2009 08:06:38 +0100
From:	Andreas Herrmann <herrmann.der.user@...glemail.com>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Dmitry Adamushko <dmitry.adamushko@...il.com>,
	linux-kernel@...r.kernel.org, "H. Peter Anvin" <hpa@...or.com>,
	Mike Travis <travis@....com>,
	Tigran Aivazian <tigran@...azian.fsnet.co.uk>,
	Thomas Gleixner <tglx@...utronix.de>,
	Borislav Petkov <borislav.petkov@....com>,
	Andreas Mohr <andi@...as.de>, Jack Steiner <steiner@....com>
Subject: [PATCH] x86, ucode-amd: Move family check to microcde_amd.c's init
 function

... to avoid useless trial to load firmware on systems with
unsupported AMD CPUs.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@....com>
---
 arch/x86/kernel/microcode_amd.c |   21 +++++++++++++++------
 1 files changed, 15 insertions(+), 6 deletions(-)

Patch is against tip/master.

Regards,
Andreas


diff --git a/arch/x86/kernel/microcode_amd.c b/arch/x86/kernel/microcode_amd.c
index 26e33bd..d0bb5ad 100644
--- a/arch/x86/kernel/microcode_amd.c
+++ b/arch/x86/kernel/microcode_amd.c
@@ -34,6 +34,7 @@ MODULE_LICENSE("GPL v2");
 #define UCODE_UCODE_TYPE           0x00000001
 
 const struct firmware *firmware;
+static int supported_cpu;
 
 struct equiv_cpu_entry {
 	u32	installed_cpu;
@@ -73,15 +74,12 @@ static struct equiv_cpu_entry *equiv_cpu_table;
 
 static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
 {
-	struct cpuinfo_x86 *c = &cpu_data(cpu);
 	u32 dummy;
 
-	memset(csig, 0, sizeof(*csig));
-	if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 0x10) {
-		pr_warning("microcode: CPU%d: AMD CPU family 0x%x not "
-			   "supported\n", cpu, c->x86);
+	if (!supported_cpu)
 		return -1;
-	}
+
+	memset(csig, 0, sizeof(*csig));
 	rdmsr(MSR_AMD64_PATCH_LEVEL, csig->rev, dummy);
 	pr_info("microcode: CPU%d: patch_level=0x%x\n", cpu, csig->rev);
 	return 0;
@@ -331,6 +329,17 @@ static void microcode_fini_cpu_amd(int cpu)
 void init_microcode_amd(struct device *device)
 {
 	const char *fw_name = "amd-ucode/microcode_amd.bin";
+	struct cpuinfo_x86 *c = &boot_cpu_data;
+
+	BUG_ON(c->x86_vendor != X86_VENDOR_AMD);
+
+	if (c->x86 < 0x10) {
+		pr_warning("microcode: AMD CPU family 0x%x not supported\n",
+			   c->x86);
+		return;
+	}
+	supported_cpu = 1;
+
 	if (request_firmware(&firmware, fw_name, device))
 		pr_err("microcode: failed to load file %s\n", fw_name);
 }
-- 
1.6.5.2

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