From: Andi Kleen <a...@linux.intel.com>
There were several reports that on some systems writing the SBOX0 PMU
initialization MSR would #GP at boot. This did not happen on all
systems -- my two test systems booted fine.
Writing the three initialization bits bit-by-bit seems to avoid the
problem. So add a special callback to do just that.
This replaces an earlier patch that disabled the SBOX.
Tested-by: patrick...@intel.com
Signed-off-by: Andi Kleen <a...@linux.intel.com>
---
.../x86/kernel/cpu/perf_event_intel_uncore_snbep.c | 33 ++++++++++++++++++++--
1 file changed, 30 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore_snbep.c
b/arch/x86/kernel/cpu/perf_event_intel_uncore_snbep.c
index 04e9a83..236dde2 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore_snbep.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore_snbep.c
@@ -490,14 +490,17 @@ static struct attribute_group
snbep_uncore_qpi_format_group = {
.attrs = snbep_uncore_qpi_formats_attr,
};
-#define SNBEP_UNCORE_MSR_OPS_COMMON_INIT() \
- .init_box = snbep_uncore_msr_init_box, \
+#define __SNBEP_UNCORE_MSR_OPS_COMMON_INIT() \
.disable_box = snbep_uncore_msr_disable_box, \
.enable_box = snbep_uncore_msr_enable_box, \
.disable_event = snbep_uncore_msr_disable_event, \
.enable_event = snbep_uncore_msr_enable_event, \
.read_counter = uncore_msr_read_counter
+#define SNBEP_UNCORE_MSR_OPS_COMMON_INIT() \
+ __SNBEP_UNCORE_MSR_OPS_COMMON_INIT(), \
+ .init_box = snbep_uncore_msr_init_box \
+
static struct intel_uncore_ops snbep_uncore_msr_ops = {
SNBEP_UNCORE_MSR_OPS_COMMON_INIT(),
};
@@ -1923,6 +1926,30 @@ static struct intel_uncore_type hswep_uncore_cbox = {
.format_group = &hswep_uncore_cbox_format_group,
};
+/*
+ * Write SBOX Initialization register bit by bit to avoid spurious #GPs
+ */
+static void hswep_uncore_sbox_msr_init_box(struct intel_uncore_box *box)
+{
+ unsigned msr = uncore_msr_box_ctl(box);
+
+ if (msr) {
+ u64 init = SNBEP_PMON_BOX_CTL_INT;
+ u64 flags = 0;
+ int i;
+
+ for_each_set_bit (i, (unsigned long *)&init, 64) {
+ flags |= (1ULL << i);
+ wrmsrl(msr, flags);
+ }
+ }
+}
+
+static struct intel_uncore_ops hswep_uncore_sbox_msr_ops = {
+ __SNBEP_UNCORE_MSR_OPS_COMMON_INIT(),
+ .init_box = hswep_uncore_sbox_msr_init_box
+};
+
static struct attribute *hswep_uncore_sbox_formats_attr[] = {
&format_attr_event.attr,
&format_attr_umask.attr,
@@ -1948,7 +1975,7 @@ static struct intel_uncore_type hswep_uncore_sbox = {
.event_mask = HSWEP_S_MSR_PMON_RAW_EVENT_MASK,
.box_ctl = HSWEP_S0_MSR_PMON_BOX_CTL,
.msr_offset = HSWEP_SBOX_MSR_OFFSET,
- .ops = &snbep_uncore_msr_ops,
+ .ops = &hswep_uncore_sbox_msr_ops,
.format_group = &hswep_uncore_sbox_format_group,
};
--
1.9.3
--
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