diff options
| author | Konstantin Belousov <kib@FreeBSD.org> | 2026-01-19 12:50:09 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2026-01-19 16:20:36 +0000 |
| commit | ad5e3cb950344f9822dbbd90f5ac7c256f97fa4c (patch) | |
| tree | 47288af611ba425c2bfdcc68f677bbab542aaf7b | |
| parent | 83d98828867591b5d842573ed6edcec7392f82df (diff) | |
x86/local_apic.c: add lapic_maxlvt() helper
that calculates the max index of the present LVT entry from the value of
the LAPIC version register.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D54773
| -rw-r--r-- | sys/x86/x86/local_apic.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/sys/x86/x86/local_apic.c b/sys/x86/x86/local_apic.c index 053d9814c14c..68f42c9eed0b 100644 --- a/sys/x86/x86/local_apic.c +++ b/sys/x86/x86/local_apic.c @@ -315,6 +315,16 @@ SYSCTL_INT(_hw_apic, OID_AUTO, ds_idle_timeout, CTLFLAG_RWTUN, static void lapic_calibrate_initcount(struct lapic *la); /* + * Calculate the max index of the present LVT entry from the value of + * the LAPIC version register. + */ +static int +lapic_maxlvt(uint32_t version) +{ + return ((version & APIC_VER_MAXLVT) >> MAXLVTSHIFT); +} + +/* * Use __nosanitizethread to exempt the LAPIC I/O accessors from KCSan * instrumentation. Otherwise, if x2APIC is not available, use of the global * lapic_map will generate a KCSan false positive. While the mapping is @@ -753,7 +763,7 @@ lapic_dump(const char* str) int i; version = lapic_read32(LAPIC_VERSION); - maxlvt = (version & APIC_VER_MAXLVT) >> MAXLVTSHIFT; + maxlvt = lapic_maxlvt(version); printf("cpu%d %s:\n", PCPU_GET(cpuid), str); printf(" ID: 0x%08x VER: 0x%08x LDR: 0x%08x DFR: 0x%08x", lapic_read32(LAPIC_ID), version, @@ -834,7 +844,7 @@ lapic_setup(int boot) la = &lapics[lapic_id()]; KASSERT(la->la_present, ("missing APIC structure")); version = lapic_read32(LAPIC_VERSION); - maxlvt = (version & APIC_VER_MAXLVT) >> MAXLVTSHIFT; + maxlvt = lapic_maxlvt(version); /* Initialize the TPR to allow all interrupts. */ lapic_set_tpr(0); @@ -990,7 +1000,7 @@ lapic_enable_pcint(void) #endif /* Fail if the PMC LVT is not present. */ - maxlvt = (lapic_read32(LAPIC_VERSION) & APIC_VER_MAXLVT) >> MAXLVTSHIFT; + maxlvt = lapic_maxlvt(lapic_read32(LAPIC_VERSION)); if (maxlvt < APIC_LVT_PMC) return (0); if (refcount_acquire(&pcint_refcnt) > 0) @@ -1014,7 +1024,7 @@ lapic_disable_pcint(void) #endif /* Fail if the PMC LVT is not present. */ - maxlvt = (lapic_read32(LAPIC_VERSION) & APIC_VER_MAXLVT) >> MAXLVTSHIFT; + maxlvt = lapic_maxlvt(lapic_read32(LAPIC_VERSION)); if (maxlvt < APIC_LVT_PMC) return; if (!refcount_release(&pcint_refcnt)) @@ -1883,7 +1893,7 @@ DB_SHOW_COMMAND_FLAGS(lapic, db_show_lapic, DB_CMD_MEMSAFE) v = lapic_read32(LAPIC_VERSION); db_printf("version = %d.%d\n", (v & APIC_VER_VERSION) >> 4, v & 0xf); - db_printf("max LVT = %d\n", (v & APIC_VER_MAXLVT) >> MAXLVTSHIFT); + db_printf("max LVT = %d\n", lapic_maxlvt(v)); v = lapic_read32(LAPIC_SVR); db_printf("SVR = %02x (%s)\n", v & APIC_SVR_VECTOR, v & APIC_SVR_ENABLE ? "enabled" : "disabled"); |