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authorAttilio Rao <attilio@FreeBSD.org>2009-11-06 10:17:08 +0000
committerAttilio Rao <attilio@FreeBSD.org>2009-11-06 10:17:08 +0000
commit2b145d43387b4bb77cee0dcb91da327fb570979d (patch)
tree6ef11235a13f492b66524b3d9fd1c6ff01e06bd3
parent92b18d813e7ca2c294849495789d3497f20171ce (diff)
downloadsrc-2b145d43387b4bb77cee0dcb91da327fb570979d.tar.gz
src-2b145d43387b4bb77cee0dcb91da327fb570979d.zip
MFC r198868, r198950:
Opteron rev E family of processor expose a bug where acq memory barriers can be broken, resulting in random breakages. Printout a warning message if affected family and model are found. Approved by: re (kib)
Notes
Notes: svn path=/releng/8.0/; revision=198978
-rw-r--r--sys/amd64/amd64/identcpu.c15
-rw-r--r--sys/i386/i386/identcpu.c15
2 files changed, 30 insertions, 0 deletions
diff --git a/sys/amd64/amd64/identcpu.c b/sys/amd64/amd64/identcpu.c
index 2c1b804affd8..19ddd96d9075 100644
--- a/sys/amd64/amd64/identcpu.c
+++ b/sys/amd64/amd64/identcpu.c
@@ -607,6 +607,21 @@ print_AMD_info(void)
printf(", %d lines/tag", (regs[2] >> 8) & 0x0f);
print_AMD_l2_assoc((regs[2] >> 12) & 0x0f);
}
+
+ /*
+ * Opteron Rev E shows a bug as in very rare occasions a read memory
+ * barrier is not performed as expected if it is followed by a
+ * non-atomic read-modify-write instruction.
+ * As long as that bug pops up very rarely (intensive machine usage
+ * on other operating systems generally generates one unexplainable
+ * crash any 2 months) and as long as a model specific fix would be
+ * impratical at this stage, print out a warning string if the broken
+ * model and family are identified.
+ */
+ if (CPUID_TO_FAMILY(cpu_id) == 0xf && CPUID_TO_MODEL(cpu_id) >= 0x20 &&
+ CPUID_TO_MODEL(cpu_id) <= 0x3f)
+ printf("WARNING: This architecture revision has known SMP "
+ "hardware bugs which may cause random instability\n");
}
static void
diff --git a/sys/i386/i386/identcpu.c b/sys/i386/i386/identcpu.c
index af0da5b28b98..cde12eb0ccdb 100644
--- a/sys/i386/i386/identcpu.c
+++ b/sys/i386/i386/identcpu.c
@@ -1303,6 +1303,21 @@ print_AMD_info(void)
(amd_whcr & 0x0100) ? "Enable" : "Disable");
}
}
+
+ /*
+ * Opteron Rev E shows a bug as in very rare occasions a read memory
+ * barrier is not performed as expected if it is followed by a
+ * non-atomic read-modify-write instruction.
+ * As long as that bug pops up very rarely (intensive machine usage
+ * on other operating systems generally generates one unexplainable
+ * crash any 2 months) and as long as a model specific fix would be
+ * impratical at this stage, print out a warning string if the broken
+ * model and family are identified.
+ */
+ if (CPUID_TO_FAMILY(cpu_id) == 0xf && CPUID_TO_MODEL(cpu_id) >= 0x20 &&
+ CPUID_TO_MODEL(cpu_id) <= 0x3f)
+ printf("WARNING: This architecture revision has known SMP "
+ "hardware bugs which may cause random instability\n");
}
static void