linux-kernel - [PATCH 2/3] x86/mce/amd: carve out MC4

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 10 Jan 2019 07:54:46 +0000
From:   "S, Shirish" <Shirish.S@....com>
To:     --cc=Borislav Petkov <bp@...en8.de>
CC:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H . Peter Anvin" <hpa@...or.com>,
        "maintainer : X86 ARCHITECTURE" <x86@...nel.org>,
        Tony Luck <tony.luck@...el.com>,
        Vishal Verma <vishal.l.verma@...el.com>,
        "open list : X86 ARCHITECTURE" <linux-kernel@...r.kernel.org>,
        "S, Shirish" <Shirish.S@....com>
Subject: [PATCH 2/3] x86/mce/amd: carve out MC4_MISC thresholding quirk

MC4_MISC thresholding quirk needs to be applied during S5 -> S0 and
S3 -> S0 state transitions, which follow different code paths, hence
carve it out so as to facilitate its application in both scenarios.

Signed-off-by: Shirish S <shirish.s@....com>
---
 arch/x86/include/asm/mce.h     |  1 +
 arch/x86/kernel/cpu/mce/core.c | 64 +++++++++++++++++++++++-------------------
 2 files changed, 36 insertions(+), 29 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index c1a812b..328b65c 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -216,6 +216,7 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr);
 static inline void mce_amd_feature_init(struct cpuinfo_x86 *c) { }
 static inline int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *sys_addr) { return -EINVAL; };
 #endif
+void quirk_fam15_mc4_misc_thresholding(void);
 
 static inline void mce_hygon_feature_init(struct cpuinfo_x86 *c) { return mce_amd_feature_init(c); }
 
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index d0c5416..51f61cf 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1570,6 +1570,39 @@ static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
 	m->cs = regs->cs;
 }
 
+/*
+ * Turn off MC4_MISC thresholding banks on all family 15 models since
+ * they're not supported there.
+ */
+void quirk_fam15_mc4_misc_thresholding(void)
+{
+	if (boot_cpu_data.x86 == 0x15) {
+		int i;
+		u64 hwcr;
+		bool need_toggle;
+		u32 msrs[] = {
+			0x00000413, /* MC4_MISC0 */
+			0xc0000408, /* MC4_MISC1 */
+		};
+
+		rdmsrl(MSR_K7_HWCR, hwcr);
+
+		/* McStatusWrEn has to be set */
+		need_toggle = !(hwcr & BIT(18));
+
+		if (need_toggle)
+			wrmsrl(MSR_K7_HWCR, hwcr | BIT(18));
+
+		/* Clear CntP bit safely */
+		for (i = 0; i < ARRAY_SIZE(msrs); i++)
+			msr_clear_bit(msrs[i], 62);
+
+		/* restore old settings */
+		if (need_toggle)
+			wrmsrl(MSR_K7_HWCR, hwcr);
+	}
+}
+
 /* Add per CPU specific workarounds here */
 static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 {
@@ -1611,35 +1644,8 @@ static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 		if (c->x86 == 0x15 && c->x86_model <= 0xf)
 			mce_flags.overflow_recov = 1;
 
-		/*
-		 * Turn off MC4_MISC thresholding banks on all models since
-		 * they're not supported there.
-		 */
-		if (c->x86 == 0x15) {
-			int i;
-			u64 hwcr;
-			bool need_toggle;
-			u32 msrs[] = {
-				0x00000413, /* MC4_MISC0 */
-				0xc0000408, /* MC4_MISC1 */
-			};
-
-			rdmsrl(MSR_K7_HWCR, hwcr);
-
-			/* McStatusWrEn has to be set */
-			need_toggle = !(hwcr & BIT(18));
-
-			if (need_toggle)
-				wrmsrl(MSR_K7_HWCR, hwcr | BIT(18));
-
-			/* Clear CntP bit safely */
-			for (i = 0; i < ARRAY_SIZE(msrs); i++)
-				msr_clear_bit(msrs[i], 62);
-
-			/* restore old settings */
-			if (need_toggle)
-				wrmsrl(MSR_K7_HWCR, hwcr);
-		}
+		quirk_fam15_mc4_misc_thresholding();
+
 	}
 
 	if (c->x86_vendor == X86_VENDOR_INTEL) {
-- 
2.7.4