This is a note to let you know that I've just added the patch titled x86/MCE/AMD: Clear DFR errors found in THR handler to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-mce-amd-clear-dfr-errors-found-in-thr-handler.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From bc1b705b0eee4c645ad8b3bbff3c8a66e9688362 Mon Sep 17 00:00:00 2001 From: Yazen Ghannam <yazen.ghannam@xxxxxxx> Date: Tue, 21 Jun 2022 15:59:43 +0000 Subject: x86/MCE/AMD: Clear DFR errors found in THR handler From: Yazen Ghannam <yazen.ghannam@xxxxxxx> commit bc1b705b0eee4c645ad8b3bbff3c8a66e9688362 upstream. AMD's MCA Thresholding feature counts errors of all severity levels, not just correctable errors. If a deferred error causes the threshold limit to be reached (it was the error that caused the overflow), then both a deferred error interrupt and a thresholding interrupt will be triggered. The order of the interrupts is not guaranteed. If the threshold interrupt handler is executed first, then it will clear MCA_STATUS for the error. It will not check or clear MCA_DESTAT which also holds a copy of the deferred error. When the deferred error interrupt handler runs it will not find an error in MCA_STATUS, but it will find the error in MCA_DESTAT. This will cause two errors to be logged. Check for deferred errors when handling a threshold interrupt. If a bank contains a deferred error, then clear the bank's MCA_DESTAT register. Define a new helper function to do the deferred error check and clearing of MCA_DESTAT. [ bp: Simplify, convert comment to passive voice. ] Fixes: 37d43acfd79f ("x86/mce/AMD: Redo error logging from APIC LVT interrupt handlers") Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20220621155943.33623-1-yazen.ghannam@xxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/cpu/mce/amd.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) --- a/arch/x86/kernel/cpu/mce/amd.c +++ b/arch/x86/kernel/cpu/mce/amd.c @@ -788,6 +788,24 @@ _log_error_bank(unsigned int bank, u32 m return status & MCI_STATUS_DEFERRED; } +static bool _log_error_deferred(unsigned int bank, u32 misc) +{ + if (!_log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS), + mca_msr_reg(bank, MCA_ADDR), misc)) + return false; + + /* + * Non-SMCA systems don't have MCA_DESTAT/MCA_DEADDR registers. + * Return true here to avoid accessing these registers. + */ + if (!mce_flags.smca) + return true; + + /* Clear MCA_DESTAT if the deferred error was logged from MCA_STATUS. */ + wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(bank), 0); + return true; +} + /* * We have three scenarios for checking for Deferred errors: * @@ -799,19 +817,8 @@ _log_error_bank(unsigned int bank, u32 m */ static void log_error_deferred(unsigned int bank) { - bool defrd; - - defrd = _log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS), - mca_msr_reg(bank, MCA_ADDR), 0); - - if (!mce_flags.smca) - return; - - /* Clear MCA_DESTAT if we logged the deferred error from MCA_STATUS. */ - if (defrd) { - wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(bank), 0); + if (_log_error_deferred(bank, 0)) return; - } /* * Only deferred errors are logged in MCA_DE{STAT,ADDR} so just check @@ -832,7 +839,7 @@ static void amd_deferred_error_interrupt static void log_error_thresholding(unsigned int bank, u64 misc) { - _log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS), mca_msr_reg(bank, MCA_ADDR), misc); + _log_error_deferred(bank, misc); } static void log_and_reset_block(struct threshold_block *block) Patches currently in stable-queue which might be from yazen.ghannam@xxxxxxx are queue-6.0/x86-mce-amd-clear-dfr-errors-found-in-thr-handler.patch queue-6.0/edac-mc_sysfs-increase-legacy-channel-support-to-12.patch