diff options
| author | Ali Mashtizadeh <ali@mashtizadeh.com> | 2026-04-04 21:30:03 +0000 |
|---|---|---|
| committer | Mitchell Horne <mhorne@FreeBSD.org> | 2026-04-09 16:35:26 +0000 |
| commit | 7a1aaca06c3384f90202dafa60440081d67d00fd (patch) | |
| tree | a242bf1563af1cdbff99ee07a6e9d8bc9fcd7de7 | |
| parent | 2f3dcbb5ef27edfee1d560395fda3c2c7fd5e5cd (diff) | |
hwpmc: Fix bug when stopping ibs-op
In ibs_stop_pmc I accidently cleared the fetch max count value rather
than the op max count value, when stopping the op counter. This
mitigates a bug in early pre-zen processors, but breaks using both
counters simultaneously. I also found that the max op count mask needs
to be extended for recent zen processors.
Reported by: Andre Fernando da Silva
Reviewed by: mhorne
Sponsored by: Netflix
Fixes: e51ef8ae490f ("hwpmc: Initial support for AMD IBS")
Pull Request: https://github.com/freebsd/freebsd-src/pull/2120
| -rw-r--r-- | sys/dev/hwpmc/hwpmc_ibs.c | 4 | ||||
| -rw-r--r-- | sys/dev/hwpmc/hwpmc_ibs.h | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/sys/dev/hwpmc/hwpmc_ibs.c b/sys/dev/hwpmc/hwpmc_ibs.c index bfc135f06884..ec1afcb47666 100644 --- a/sys/dev/hwpmc/hwpmc_ibs.c +++ b/sys/dev/hwpmc/hwpmc_ibs.c @@ -270,7 +270,7 @@ ibs_stop_pmc(int cpu __diagused, int ri, struct pmc *pm) * Turn off the ENABLE bit, but unfortunately there are a few quirks * that generate excess NMIs. Workaround #420 in the Revision Guide * for AMD Family 10h Processors 41322 Rev. 3.92 March 2012. requires - * that we clear the count before clearing enable. + * that we clear the max count before clearing enable. * * Even after clearing the counter spurious NMIs are still possible so * we use a per-CPU atomic variable to notify the interrupt handler we @@ -290,7 +290,7 @@ ibs_stop_pmc(int cpu __diagused, int ri, struct pmc *pm) wrmsr(IBS_FETCH_CTL, config); break; case IBS_PMC_OP: - wrmsr(IBS_FETCH_CTL, config & ~IBS_FETCH_CTL_MAXCNTMASK); + wrmsr(IBS_OP_CTL, config & ~IBS_OP_CTL_MAXCNTMASK); DELAY(1); config &= ~IBS_OP_CTL_ENABLE; wrmsr(IBS_OP_CTL, config); diff --git a/sys/dev/hwpmc/hwpmc_ibs.h b/sys/dev/hwpmc/hwpmc_ibs.h index c66d54672543..1616a746ffef 100644 --- a/sys/dev/hwpmc/hwpmc_ibs.h +++ b/sys/dev/hwpmc/hwpmc_ibs.h @@ -112,7 +112,7 @@ #define IBS_OP_CTL_VALID (1ULL << 18) /* Valid */ #define IBS_OP_CTL_ENABLE (1ULL << 17) /* Enable */ #define IBS_OP_CTL_L3MISSONLY (1ULL << 16) /* L3 Miss Filtering */ -#define IBS_OP_CTL_MAXCNTMASK 0x0000FFFFULL +#define IBS_OP_CTL_MAXCNTMASK 0x07F0FFFFULL #define IBS_OP_CTL_LDLAT_TO_CTL(_c) ((((ldlat) >> 7) - 1) << 59) #define IBS_OP_INTERVAL_TO_CTL(_c) ((((_c) >> 4) & 0x0000FFFFULL) | ((_c) & 0x07F00000)) |