+++ /dev/null
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Yazen Ghannam <yazen.ghannam@amd.com>
-Date: Thu, 21 Nov 2019 08:15:08 -0600
-Subject: [PATCH] x86/MCE/AMD: Allow Reserved types to be overwritten in
- smca_banks[]
-
-Each logical CPU in Scalable MCA systems controls a unique set of MCA
-banks in the system. These banks are not shared between CPUs. The bank
-types and ordering will be the same across CPUs on currently available
-systems.
-
-However, some CPUs may see a bank as Reserved/Read-as-Zero (RAZ) while
-other CPUs do not. In this case, the bank seen as Reserved on one CPU is
-assumed to be the same type as the bank seen as a known type on another
-CPU.
-
-In general, this occurs when the hardware represented by the MCA bank
-is disabled, e.g. disabled memory controllers on certain models, etc.
-The MCA bank is disabled in the hardware, so there is no possibility of
-getting an MCA/MCE from it even if it is assumed to have a known type.
-
-For example:
-
-Full system:
- Bank | Type seen on CPU0 | Type seen on CPU1
- ------------------------------------------------
- 0 | LS | LS
- 1 | UMC | UMC
- 2 | CS | CS
-
-System with hardware disabled:
- Bank | Type seen on CPU0 | Type seen on CPU1
- ------------------------------------------------
- 0 | LS | LS
- 1 | UMC | RAZ
- 2 | CS | CS
-
-For this reason, there is a single, global struct smca_banks[] that is
-initialized at boot time. This array is initialized on each CPU as it
-comes online. However, the array will not be updated if an entry already
-exists.
-
-This works as expected when the first CPU (usually CPU0) has all
-possible MCA banks enabled. But if the first CPU has a subset, then it
-will save a "Reserved" type in smca_banks[]. Successive CPUs will then
-not be able to update smca_banks[] even if they encounter a known bank
-type.
-
-This may result in unexpected behavior. Depending on the system
-configuration, a user may observe issues enumerating the MCA
-thresholding sysfs interface. The issues may be as trivial as sysfs
-entries not being available, or as severe as system hangs.
-
-For example:
-
- Bank | Type seen on CPU0 | Type seen on CPU1
- ------------------------------------------------
- 0 | LS | LS
- 1 | RAZ | UMC
- 2 | CS | CS
-
-Extend the smca_banks[] entry check to return if the entry is a
-non-reserved type. Otherwise, continue so that CPUs that encounter a
-known bank type can update smca_banks[].
-
-Fixes: 68627a697c19 ("x86/mce/AMD, EDAC/mce_amd: Enumerate Reserved SMCA bank type")
-Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
-Signed-off-by: Borislav Petkov <bp@suse.de>
-Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
----
- arch/x86/kernel/cpu/mce/amd.c | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
-diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
-index 6ea7fdc82f3c..08e09c8c269f 100644
---- a/arch/x86/kernel/cpu/mce/amd.c
-+++ b/arch/x86/kernel/cpu/mce/amd.c
-@@ -266,7 +266,7 @@ static void smca_configure(unsigned int bank, unsigned int cpu)
- smca_set_misc_banks_map(bank, cpu);
-
- /* Return early if this bank was already initialized. */
-- if (smca_banks[bank].hwid)
-+ if (smca_banks[bank].hwid && smca_banks[bank].hwid->hwid_mcatype != 0)
- return;
-
- if (rdmsr_safe_on_cpu(cpu, MSR_AMD64_SMCA_MCx_IPID(bank), &low, &high)) {
projects / pve-kernel.git / blobdiff