[kvm-unit-tests,v3,8/9] AArch32: apply errata framework to unsafe pmccntr64 test

Commit Message

Andrew Jones June 13, 2017, 11:54 a.m. UTC

Signed-off-by: Andrew Jones <[e-mail]>
---
 arm/pmu.c  | 26 ++++++++++++++++++--------
 errata.txt |  1 +
 2 files changed, 19 insertions(+), 8 deletions(-)

Patch

diff --git a/arm/pmu.c b/arm/pmu.c
index 74848988a678..1ac692023e5e 100644
--- a/arm/pmu.c
+++ b/arm/pmu.c
@@ -14,6 +14,7 @@ 
  * for more details.
  */
 #include "libcflat.h"
+#include "errata.h"
 #include "asm/barrier.h"
 #include "asm/sysreg.h"
 #include "asm/processor.h"
@@ -57,18 +58,12 @@  static inline uint8_t get_pmu_version(void)
 
 static inline uint64_t get_pmccntr(void)
 {
-	if (pmu_version == 0x3)
-		return read_sysreg(PMCCNTR64);
-	else
-		return read_sysreg(PMCCNTR32);
+	return read_sysreg(PMCCNTR32);
 }
 
 static inline void set_pmccntr(uint64_t value)
 {
-	if (pmu_version == 0x3)
-		write_sysreg(value, PMCCNTR64);
-	else
-		write_sysreg(value & 0xffffffff, PMCCNTR32);
+	write_sysreg(value & 0xffffffff, PMCCNTR32);
 }
 
 /* PMCCFILTR is an obsolete name for PMXEVTYPER31 in ARMv7 */
@@ -267,6 +262,19 @@  static bool check_cpi(int cpi)
 	return true;
 }
 
+static void pmccntr64_test(void)
+{
+#ifdef __arm__
+	if (pmu_version == 0x3) {
+		if (ERRATA(9e3f7a296940)) {
+			write_sysreg(0xdead, PMCCNTR64);
+			report("pmccntr64", read_sysreg(PMCCNTR64) == 0xdead);
+		} else
+			report_skip("Skipping unsafe pmccntr64 test. Set ERRATA_9e3f7a296940=y to enable.");
+	}
+#endif
+}
+
 /* Return FALSE if no PMU found, otherwise return TRUE */
 bool pmu_probe(void)
 {
@@ -293,5 +301,7 @@  int main(int argc, char *argv[])
 	report("Monotonically increasing cycle count", check_cycles_increase());
 	report("Cycle/instruction ratio", check_cpi(cpi));
 
+	pmccntr64_test();
+
 	return report_summary();
 }
diff --git a/errata.txt b/errata.txt
index 95b66c837c63..682d7aa067b9 100644
--- a/errata.txt
+++ b/errata.txt
@@ -2,4 +2,5 @@ 
 # commit	: minimum kernel	: summary
 # 12 hex digits	: version		:
 #---------------:-----------------------:--------------------------------------
+9e3f7a296940	: 4.9			: arm64: KVM: pmu: Fix AArch32 cycle counter access
 #---------------:-----------------------:--------------------------------------