From: Yazen Ghannam Date: Tue, 24 Jun 2025 14:15:59 +0000 (+0000) Subject: x86/mce/amd: Fix threshold limit reset X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=5f6e3b720694ad771911f637a51930f511427ce1;p=linux-block.git x86/mce/amd: Fix threshold limit reset The MCA threshold limit must be reset after servicing the interrupt. Currently, the restart function doesn't have an explicit check for this. It makes some assumptions based on the current limit and what's in the registers. These assumptions don't always hold, so the limit won't be reset in some cases. Make the reset condition explicit. Either an interrupt/overflow has occurred or the bank is being initialized. Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Cc: stable@vger.kernel.org Link: https://lore.kernel.org/20250624-wip-mca-updates-v4-4-236dd74f645f@amd.com --- diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c index 6820ebce5d46..5c4eb28c3ac9 100644 --- a/arch/x86/kernel/cpu/mce/amd.c +++ b/arch/x86/kernel/cpu/mce/amd.c @@ -350,7 +350,6 @@ static void smca_configure(unsigned int bank, unsigned int cpu) struct thresh_restart { struct threshold_block *b; - int reset; int set_lvt_off; int lvt_off; u16 old_limit; @@ -432,13 +431,13 @@ static void threshold_restart_bank(void *_tr) rdmsr(tr->b->address, lo, hi); - if (tr->b->threshold_limit < (hi & THRESHOLD_MAX)) - tr->reset = 1; /* limit cannot be lower than err count */ - - if (tr->reset) { /* reset err count and overflow bit */ - hi = - (hi & ~(MASK_ERR_COUNT_HI | MASK_OVERFLOW_HI)) | - (THRESHOLD_MAX - tr->b->threshold_limit); + /* + * Reset error count and overflow bit. + * This is done during init or after handling an interrupt. + */ + if (hi & MASK_OVERFLOW_HI || tr->set_lvt_off) { + hi &= ~(MASK_ERR_COUNT_HI | MASK_OVERFLOW_HI); + hi |= THRESHOLD_MAX - tr->b->threshold_limit; } else if (tr->old_limit) { /* change limit w/o reset */ int new_count = (hi & THRESHOLD_MAX) + (tr->old_limit - tr->b->threshold_limit);