linux-kernel - [PATCH v2 06/10] x86/mce: Convert multiple if () statements into a switch() statement

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Message-Id: <20241016123036.21366-7-qiuxu.zhuo@intel.com>
Date: Wed, 16 Oct 2024 20:30:32 +0800
From: Qiuxu Zhuo <qiuxu.zhuo@...el.com>
To: tony.luck@...el.com,
	bp@...en8.de
Cc: tglx@...utronix.de,
	dave.hansen@...ux.intel.com,
	mingo@...hat.com,
	hpa@...or.com,
	x86@...nel.org,
	linux-edac@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	qiuxu.zhuo@...el.com
Subject: [PATCH v2 06/10] x86/mce: Convert multiple if () statements into a switch() statement

Convert the multiple if() statements used for vendor differentiation
into a switch() statement for better readability.

As a bonus, the size of new generated text is reduced by 16 bytes.

  $ size core.o.*
     text	   data	    bss	    dec	    hex	filename
    21364	   4181	   3776	  29321	   7289	core.o.old
    21348	   4181	   3776	  29305	   7279	core.o.new

No functional changes intended.

Reviewed-by: Tony Luck <tony.luck@...el.com>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@...el.com>
---
 arch/x86/kernel/cpu/mce/core.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 725c1d6fb1e5..40672fe0991a 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1892,7 +1892,8 @@ static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 	}
 
 	/* This should be disabled by the BIOS, but isn't always */
-	if (c->x86_vendor == X86_VENDOR_AMD) {
+	switch (c->x86_vendor) {
+	case X86_VENDOR_AMD:
 		if (c->x86 == 15 && this_cpu_read(mce_num_banks) > 4) {
 			/*
 			 * disable GART TBL walk error reporting, which
@@ -1925,9 +1926,9 @@ static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 		if (c->x86 >= 0x17 && c->x86 <= 0x1A)
 			mce_flags.zen_ifu_quirk = 1;
 
-	}
+		break;
 
-	if (c->x86_vendor == X86_VENDOR_INTEL) {
+	case X86_VENDOR_INTEL:
 		/*
 		 * SDM documents that on family 6 bank 0 should not be written
 		 * because it aliases to another special BIOS controlled
@@ -1964,9 +1965,10 @@ static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 		 */
 		if (c->x86_vfm == INTEL_SKYLAKE_X)
 			mce_flags.skx_repmov_quirk = 1;
-	}
 
-	if (c->x86_vendor == X86_VENDOR_ZHAOXIN) {
+		break;
+
+	case X86_VENDOR_ZHAOXIN:
 		/*
 		 * All newer Zhaoxin CPUs support MCE broadcasting. Enable
 		 * synchronization with a one second timeout.
@@ -1975,6 +1977,8 @@ static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 			if (cfg->monarch_timeout < 0)
 				cfg->monarch_timeout = USEC_PER_SEC;
 		}
+
+		break;
 	}
 
 	if (cfg->monarch_timeout < 0)
-- 
2.17.1