From a3e80b2fcc50c89d8f4f17c644fbf5f505e8f6b6 Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Tue, 24 Jun 2025 14:15:59 +0000 Subject: [PATCH] x86/mce/amd: Fix threshold limit reset commit 5f6e3b720694ad771911f637a51930f511427ce1 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/mce/amd.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c index 1cf34fcc3a8e..816b3d0512ba 100644 --- a/arch/x86/kernel/cpu/mce/amd.c +++ b/arch/x86/kernel/cpu/mce/amd.c @@ -290,7 +290,6 @@ 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; @@ -381,13 +380,13 @@ 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);