Author: kib
Date: Wed Oct 14 22:57:50 2020
New Revision: 366712
URL: https://svnweb.freebsd.org/changeset/base/366712
Log:
Limit workaround for errata E400 to appropriate AMD cpus.
From Linux sources and several datasheets I looked at, it seems that
the workaround is only needed on families 0xf and 0x10. For instance,
Ryzens do not implement the accessed MSR at all, it is documented as
reserved. Also, hypervisors should not allow guest to put CPU into
idle state, so activate workaround only when on bare hardware.
While there, style the code:
move MSR defines to specialreg.h
move identification to initcpu.c
Reported by: whu
Reviewed by: avg
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D26470
Modified:
head/sys/amd64/amd64/initcpu.c
head/sys/amd64/amd64/machdep.c
head/sys/i386/i386/initcpu.c
head/sys/i386/i386/machdep.c
head/sys/x86/include/specialreg.h
head/sys/x86/include/x86_var.h
head/sys/x86/x86/cpu_machdep.c
Modified: head/sys/amd64/amd64/initcpu.c
==============================================================================
--- head/sys/amd64/amd64/initcpu.c Wed Oct 14 22:51:40 2020
(r366711)
+++ head/sys/amd64/amd64/initcpu.c Wed Oct 14 22:57:50 2020
(r366712)
@@ -69,6 +69,23 @@ init_amd(void)
uint64_t msr;
/*
+ * C1E renders the local APIC timer dead, so we disable it by
+ * reading the Interrupt Pending Message register and clearing
+ * both C1eOnCmpHalt (bit 28) and SmiOnCmpHalt (bit 27).
+ *
+ * Reference:
+ * "BIOS and Kernel Developer's Guide for AMD NPT Family 0Fh
Processors"
+ * #32559 revision 3.00+
+ *
+ * Detect the presence of C1E capability mostly on latest
+ * dual-cores (or future) k8 family. Affected models range is
+ * taken from Linux sources.
+ */
+ if ((CPUID_TO_FAMILY(cpu_id) == 0xf ||
+ CPUID_TO_FAMILY(cpu_id) == 0x10) && (cpu_feature2 & CPUID2_HV) == 0)
+ cpu_amdc1e_bug = 1;
+
+ /*
* Work around Erratum 721 for Family 10h and 12h processors.
* These processors may incorrectly update the stack pointer
* after a long series of push and/or near-call instructions,
Modified: head/sys/amd64/amd64/machdep.c
==============================================================================
--- head/sys/amd64/amd64/machdep.c Wed Oct 14 22:51:40 2020
(r366711)
+++ head/sys/amd64/amd64/machdep.c Wed Oct 14 22:57:50 2020
(r366712)
@@ -1928,8 +1928,6 @@ hammer_time(u_int64_t modulep, u_int64_t physfree)
if (env != NULL)
strlcpy(kernelname, env, sizeof(kernelname));
- cpu_probe_amdc1e();
-
kcsan_cpu_init(0);
#ifdef FDT
Modified: head/sys/i386/i386/initcpu.c
==============================================================================
--- head/sys/i386/i386/initcpu.c Wed Oct 14 22:51:40 2020
(r366711)
+++ head/sys/i386/i386/initcpu.c Wed Oct 14 22:57:50 2020
(r366712)
@@ -720,8 +720,8 @@ initializecpu(void)
break;
}
break;
-#ifdef CPU_ATHLON_SSE_HACK
case CPU_VENDOR_AMD:
+#ifdef CPU_ATHLON_SSE_HACK
/*
* Sometimes the BIOS doesn't enable SSE instructions.
* According to AMD document 20734, the mobile
@@ -738,8 +738,16 @@ initializecpu(void)
do_cpuid(1, regs);
cpu_feature = regs[3];
}
- break;
#endif
+ /*
+ * Detect C1E that breaks APIC. See comment in
+ * amd64/initcpu.c.
+ */
+ if ((CPUID_TO_FAMILY(cpu_id) == 0xf ||
+ CPUID_TO_FAMILY(cpu_id) == 0x10) &&
+ (cpu_feature2 & CPUID2_HV) == 0)
+ cpu_amdc1e_bug = 1;
+ break;
case CPU_VENDOR_CENTAUR:
init_via();
break;
Modified: head/sys/i386/i386/machdep.c
==============================================================================
--- head/sys/i386/i386/machdep.c Wed Oct 14 22:51:40 2020
(r366711)
+++ head/sys/i386/i386/machdep.c Wed Oct 14 22:57:50 2020
(r366712)
@@ -2505,8 +2505,6 @@ init386(int first)
thread0.td_pcb->pcb_ext = 0;
thread0.td_frame = &proc0_tf;
- cpu_probe_amdc1e();
-
#ifdef FDT
x86_init_fdt();
#endif
Modified: head/sys/x86/include/specialreg.h
==============================================================================
--- head/sys/x86/include/specialreg.h Wed Oct 14 22:51:40 2020
(r366711)
+++ head/sys/x86/include/specialreg.h Wed Oct 14 22:57:50 2020
(r366712)
@@ -1126,6 +1126,7 @@
#define MSR_NB_CFG1 0xc001001f /* NB configuration 1 */
#define MSR_K8_UCODE_UPDATE 0xc0010020 /* update microcode */
#define MSR_MC0_CTL_MASK 0xc0010044
+#define MSR_AMDK8_IPM 0xc0010055
#define MSR_P_STATE_LIMIT 0xc0010061 /* P-state Current Limit
Register */
#define MSR_P_STATE_CONTROL 0xc0010062 /* P-state Control Register */
#define MSR_P_STATE_STATUS 0xc0010063 /* P-state Status Register */
@@ -1142,6 +1143,9 @@
/* MSR_VM_CR related */
#define VM_CR_SVMDIS 0x10 /* SVM: disabled by BIOS */
+
+#define AMDK8_SMIONCMPHALT (1ULL << 27)
+#define AMDK8_C1EONCMPHALT (1ULL << 28)
/* VIA ACE crypto featureset: for via_feature_rng */
#define VIA_HAS_RNG 1 /* cpu has RNG */
Modified: head/sys/x86/include/x86_var.h
==============================================================================
--- head/sys/x86/include/x86_var.h Wed Oct 14 22:51:40 2020
(r366711)
+++ head/sys/x86/include/x86_var.h Wed Oct 14 22:57:50 2020
(r366712)
@@ -94,6 +94,7 @@ extern int hw_ssb_active;
extern int x86_taa_enable;
extern int cpu_flush_rsb_ctxsw;
extern int x86_rngds_mitg_enable;
+extern int cpu_amdc1e_bug;
struct pcb;
struct thread;
Modified: head/sys/x86/x86/cpu_machdep.c
==============================================================================
--- head/sys/x86/x86/cpu_machdep.c Wed Oct 14 22:51:40 2020
(r366711)
+++ head/sys/x86/x86/cpu_machdep.c Wed Oct 14 22:57:50 2020
(r366712)
@@ -486,7 +486,9 @@ cpu_mwait_usable(void)
}
void (*cpu_idle_hook)(sbintime_t) = NULL; /* ACPI idle hook. */
-static int cpu_ident_amdc1e = 0; /* AMD C1E supported. */
+
+int cpu_amdc1e_bug = 0; /* AMD C1E APIC workaround
required. */
+
static int idle_mwait = 1; /* Use MONITOR/MWAIT for short idle. */
SYSCTL_INT(_machdep, OID_AUTO, idle_mwait, CTLFLAG_RWTUN, &idle_mwait,
0, "Use MONITOR/MWAIT for short idle");
@@ -587,35 +589,6 @@ cpu_idle_spin(sbintime_t sbt)
}
}
-/*
- * C1E renders the local APIC timer dead, so we disable it by
- * reading the Interrupt Pending Message register and clearing
- * both C1eOnCmpHalt (bit 28) and SmiOnCmpHalt (bit 27).
- *
- * Reference:
- * "BIOS and Kernel Developer's Guide for AMD NPT Family 0Fh Processors"
- * #32559 revision 3.00+
- */
-#define MSR_AMDK8_IPM 0xc0010055
-#define AMDK8_SMIONCMPHALT (1ULL << 27)
-#define AMDK8_C1EONCMPHALT (1ULL << 28)
-#define AMDK8_CMPHALT (AMDK8_SMIONCMPHALT |
AMDK8_C1EONCMPHALT)
-
-void
-cpu_probe_amdc1e(void)
-{
-
- /*
- * Detect the presence of C1E capability mostly on latest
- * dual-cores (or future) k8 family.
- */
- if (cpu_vendor_id == CPU_VENDOR_AMD &&
- (cpu_id & 0x00000f00) == 0x00000f00 &&
- (cpu_id & 0x0fff0000) >= 0x00040000) {
- cpu_ident_amdc1e = 1;
- }
-}
-
void (*cpu_idle_fn)(sbintime_t) = cpu_idle_acpi;
void
@@ -645,10 +618,11 @@ cpu_idle(int busy)
}
/* Apply AMD APIC timer C1E workaround. */
- if (cpu_ident_amdc1e && cpu_disable_c3_sleep) {
+ if (cpu_amdc1e_bug && cpu_disable_c3_sleep) {
msr = rdmsr(MSR_AMDK8_IPM);
- if (msr & AMDK8_CMPHALT)
- wrmsr(MSR_AMDK8_IPM, msr & ~AMDK8_CMPHALT);
+ if ((msr & (AMDK8_SMIONCMPHALT | AMDK8_C1EONCMPHALT)) != 0)
+ wrmsr(MSR_AMDK8_IPM, msr & ~(AMDK8_SMIONCMPHALT |
+ AMDK8_C1EONCMPHALT));
}
/* Call main idle method. */
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