Author: jkim
Date: Fri Mar 30 16:32:41 2012
New Revision: 233702
URL: http://svn.freebsd.org/changeset/base/233702
Log:
Work around Erratum 721 for AMD Family 10h and 12h processors.
"Under a highly specific and detailed set of internal timing conditions,
the processor may incorrectly update the stack pointer after a long series
of push and/or near-call instructions, or a long series of pop and/or
near-return instructions. The processor must be in 64-bit mode for this
erratum to occur."
MFC after: 3 days
Modified:
head/sys/amd64/amd64/initcpu.c
Modified: head/sys/amd64/amd64/initcpu.c
==============================================================================
--- head/sys/amd64/amd64/initcpu.c Fri Mar 30 15:08:09 2012
(r233701)
+++ head/sys/amd64/amd64/initcpu.c Fri Mar 30 16:32:41 2012
(r233702)
@@ -79,6 +79,27 @@ SYSCTL_UINT(_hw, OID_AUTO, via_feature_r
SYSCTL_UINT(_hw, OID_AUTO, via_feature_xcrypt, CTLFLAG_RD,
&via_feature_xcrypt, 0, "VIA xcrypt feature available in CPU");
+static void
+init_amd(void)
+{
+
+ /*
+ * 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,
+ * or a long series of pop and/or near-return instructions.
+ *
+ * http://support.amd.com/us/Processor_TechDocs/41322_10h_Rev_Gd.pdf
+ * http://support.amd.com/us/Processor_TechDocs/44739_12h_Rev_Gd.pdf
+ */
+ switch (CPUID_TO_FAMILY(cpu_id)) {
+ case 0x10:
+ case 0x12:
+ wrmsr(0xc0011029, rdmsr(0xc0011029) | 1);
+ break;
+ }
+}
+
/*
* Initialize special VIA features
*/
@@ -135,8 +156,14 @@ initializecpu(void)
wrmsr(MSR_EFER, msr);
pg_nx = PG_NX;
}
- if (cpu_vendor_id == CPU_VENDOR_CENTAUR)
+ switch (cpu_vendor_id) {
+ case CPU_VENDOR_AMD:
+ init_amd();
+ break;
+ case CPU_VENDOR_CENTAUR:
init_via();
+ break;
+ }
}
void
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