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From: Andi Kleen <ak@suse.de>
To: "Jan Beulich" <jbeulich@novell.com>,
	patches@x86-64.org, linux-kernel@vger.kernel.org
Subject: [PATCH x86 for review II] [17/39] x86_64: Tighten mce_amd driver MSR reads
Date: Mon, 12 Feb 2007 08:38:04 +0100 (CET)	[thread overview]
Message-ID: <20070212073804.7953A13D7F@wotan.suse.de> (raw)
In-Reply-To: <20070212837.963446000@suse.de>


From: "Jan Beulich" <jbeulich@novell.com>

while debugging an unrelated problem in Xen, I noticed odd reads from
non-existent MSRs. Having now found time to look why these happen, I
came up with below patch, which
- prevents accessing MCi_MISCj with j > 0 when the block pointer in
MCi_MISC0 is zero
- accesses only contiguous MCi_MISCj until a non-implemented one is
found
- doesn't touch unimplemented blocks in mce_threshold_interrupt at all
- gives names to two bits previously derived from MASK_VALID_HI (it
took me some time to understand the code without this)

The first three items, besides being apparently closer to the spec, should
namely help cutting down on the time mce_threshold_interrupt() takes.

Signed-off-by: Andi Kleen <ak@suse.de>

---
 arch/x86_64/kernel/mce_amd.c |   40 +++++++++++++++++++++++++---------------
 1 file changed, 25 insertions(+), 15 deletions(-)

Index: linux/arch/x86_64/kernel/mce_amd.c
===================================================================
--- linux.orig/arch/x86_64/kernel/mce_amd.c
+++ linux/arch/x86_64/kernel/mce_amd.c
@@ -37,6 +37,8 @@
 #define THRESHOLD_MAX     0xFFF
 #define INT_TYPE_APIC     0x00020000
 #define MASK_VALID_HI     0x80000000
+#define MASK_CNTP_HI      0x40000000
+#define MASK_LOCKED_HI    0x20000000
 #define MASK_LVTOFF_HI    0x00F00000
 #define MASK_COUNT_EN_HI  0x00080000
 #define MASK_INT_TYPE_HI  0x00060000
@@ -122,14 +124,17 @@ void __cpuinit mce_amd_feature_init(stru
 		for (block = 0; block < NR_BLOCKS; ++block) {
 			if (block == 0)
 				address = MSR_IA32_MC0_MISC + bank * 4;
-			else if (block == 1)
-				address = MCG_XBLK_ADDR
-					+ ((low & MASK_BLKPTR_LO) >> 21);
+			else if (block == 1) {
+				address = (low & MASK_BLKPTR_LO) >> 21;
+				if (!address)
+					break;
+				address += MCG_XBLK_ADDR;
+			}
 			else
 				++address;
 
 			if (rdmsr_safe(address, &low, &high))
-				continue;
+				break;
 
 			if (!(high & MASK_VALID_HI)) {
 				if (block)
@@ -138,8 +143,8 @@ void __cpuinit mce_amd_feature_init(stru
 					break;
 			}
 
-			if (!(high & MASK_VALID_HI >> 1)  ||
-			     (high & MASK_VALID_HI >> 2))
+			if (!(high & MASK_CNTP_HI)  ||
+			     (high & MASK_LOCKED_HI))
 				continue;
 
 			if (!block)
@@ -187,17 +192,22 @@ asmlinkage void mce_threshold_interrupt(
 
 	/* assume first bank caused it */
 	for (bank = 0; bank < NR_BANKS; ++bank) {
+		if (!(per_cpu(bank_map, m.cpu) & (1 << bank)))
+			continue;
 		for (block = 0; block < NR_BLOCKS; ++block) {
 			if (block == 0)
 				address = MSR_IA32_MC0_MISC + bank * 4;
-			else if (block == 1)
-				address = MCG_XBLK_ADDR
-					+ ((low & MASK_BLKPTR_LO) >> 21);
+			else if (block == 1) {
+				address = (low & MASK_BLKPTR_LO) >> 21;
+				if (!address)
+					break;
+				address += MCG_XBLK_ADDR;
+			}
 			else
 				++address;
 
 			if (rdmsr_safe(address, &low, &high))
-				continue;
+				break;
 
 			if (!(high & MASK_VALID_HI)) {
 				if (block)
@@ -206,8 +216,8 @@ asmlinkage void mce_threshold_interrupt(
 					break;
 			}
 
-			if (!(high & MASK_VALID_HI >> 1)  ||
-			     (high & MASK_VALID_HI >> 2))
+			if (!(high & MASK_CNTP_HI)  ||
+			     (high & MASK_LOCKED_HI))
 				continue;
 
 			if (high & MASK_OVERFLOW_HI) {
@@ -385,7 +395,7 @@ static __cpuinit int allocate_threshold_
 		return 0;
 
 	if (rdmsr_safe(address, &low, &high))
-		goto recurse;
+		return 0;
 
 	if (!(high & MASK_VALID_HI)) {
 		if (block)
@@ -394,8 +404,8 @@ static __cpuinit int allocate_threshold_
 			return 0;
 	}
 
-	if (!(high & MASK_VALID_HI >> 1)  ||
-	     (high & MASK_VALID_HI >> 2))
+	if (!(high & MASK_CNTP_HI)  ||
+	     (high & MASK_LOCKED_HI))
 		goto recurse;
 
 	b = kzalloc(sizeof(struct threshold_block), GFP_KERNEL);

  parent reply	other threads:[~2007-02-12  7:40 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-12  7:37 [PATCH x86 for review II] [1/39] i386: move startup_32() in text.head section Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [2/39] x86_64: Break init() in two parts to avoid MODPOST warnings Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [3/39] i386: arch/i386/kernel/cpu/mcheck/mce.c should #include <asm/mce.h> Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [4/39] i386: add idle notifier Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [5/39] i386: improve sched_clock() on i686 Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [6/39] i386: romsignature/checksum cleanup Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [7/39] x86_64: Fix fake numa for x86_64 machines with big IO hole Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [8/39] x86_64: Remove fastcall references in x86_64 code Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [9/39] x86_64: Use constant instead of raw number in x86_64 ioperm.c Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [10/39] x86_64: Handle 32 bit PerfMon Counter writes cleanly in x86_64 nmi_watchdog Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [11/39] i386: Handle 32 bit PerfMon Counter writes cleanly in i386 nmi_watchdog Andi Kleen
2007-02-12  7:37 ` [PATCH x86 for review II] [12/39] i386: Handle 32 bit PerfMon Counter writes cleanly in oprofile Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [13/39] i386: CONFIG_PHYSICAL_ALIGN limited to 4M? Andi Kleen
2007-02-13  6:36   ` Rene Herman
2007-02-12  7:38 ` [PATCH x86 for review II] [14/39] x86_64: cleanup Doc/x86_64/ files Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [15/39] x86_64: list x86_64 quilt tree Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [16/39] x86: simplify notify_page_fault() Andi Kleen
2007-02-12  7:38 ` Andi Kleen [this message]
2007-02-12  7:38 ` [PATCH x86 for review II] [18/39] x86_64: Allow to run a program when a machine check event is detected Andi Kleen
2007-02-12  7:54   ` Oliver Neukum
2007-02-12  8:04     ` Andi Kleen
2007-02-12  8:11       ` Bauke Jan Douma
2007-02-12 15:05       ` [patches] " Pavel Machek
2007-02-12  7:38 ` [PATCH x86 for review II] [19/39] x86_64: remove get_pmd() Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [20/39] i386: Small cleanup to TLB flush code Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [21/39] i386: rdmsr_on_cpu, wrmsr_on_cpu Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [22/39] x86_64: Kconfig typos Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [23/39] i386: use smp_call_function_single() Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [24/39] " Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [25/39] x86_64: Fix preprocessor condition Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [26/39] i386: fix 32-bit ioctls on x64_32 Andi Kleen
2007-02-12 13:24   ` Giuliano Procida
2007-02-12 22:28     ` Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [27/39] i386: APM on i386 Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [28/39] i386: fix size_or_mask and size_and_mask Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [29/39] x86_64: - Ignore long SMI interrupts in clock calibration code - update 1 Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [30/39] x86_64: Check return value of putreg in PTRACE_SETREGS Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [31/39] x86_64: Unexport __supported_pte_mask Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [32/39] x86_64: x86_64 - Fix FS/GS registers for VT execution Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [33/39] x86_64: Fix off by one error in IOMMU boundary checking Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [34/39] i386: Use stack arguments for calling into EFI Andi Kleen
2007-02-12 19:45   ` Frédéric RISS
2007-02-12  7:38 ` [PATCH x86 for review II] [35/39] x86_64: Don't reserve ROMs Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [36/39] x86_64: define dma noncoherent API functions Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [37/39] x86_64: robustify bad_dma_address handling Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [38/39] x86: fix laptop bootup hang in init_acpi() Andi Kleen
2007-02-12  7:38 ` [PATCH x86 for review II] [39/39] i386: All Transmeta CPUs have constant TSCs Andi Kleen

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