Commit a3a529d1 authored Oct 21, 2014 by Borislav Petkov

x86, MCE, AMD: Drop software-defined bank in error thresholding



Aravind had the good question about why we're assigning a
software-defined bank when reporting error thresholding errors instead
of simply using the bank which reports the last error causing the
overflow.

Digging through git history, it pointed to

95268664 ("[PATCH] x86_64: mce_amd support for family 0x10 processors")

which added that functionality. The problem with this, however, is that
tools don't know about software-defined banks and get puzzled. So drop
that K8_MCE_THRESHOLD_BASE and simply use the hw bank reporting the
thresholding interrupt.

Save us a couple of MSR reads while at it.

Reported-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
Link: https://lkml.kernel.org/r/5435B206.60402@amd.com


Signed-off-by: Borislav Petkov <bp@suse.de>

parent 69b95758

arch/x86/include/asm/mce.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -78,7 +78,6 @@
		/* Software defined banks */
		#define MCE_EXTENDED_BANK 128
		#define MCE_THERMAL_BANK (MCE_EXTENDED_BANK + 0)
		#define K8_MCE_THRESHOLD_BASE (MCE_EXTENDED_BANK + 1)

		#define MCE_LOG_LEN 32
		#define MCE_LOG_SIGNATURE "MACHINECHECK"

arch/x86/kernel/cpu/mcheck/mce_amd.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -318,10 +318,9 @@ static void amd_threshold_interrupt(void)

		log:
		mce_setup(&m);
		rdmsrl(MSR_IA32_MCG_STATUS, m.mcgstatus);
		rdmsrl(address, m.misc);
		rdmsrl(MSR_IA32_MCx_STATUS(bank), m.status);
		m.bank = K8_MCE_THRESHOLD_BASE + bank * NR_BLOCKS + block;
		m.misc = ((u64)high << 32) \| low;
		m.bank = bank;
		mce_log(&m);

		wrmsrl(MSR_IA32_MCx_STATUS(bank), 0);

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