target/arm: PMU: Set PMCR.N to 4
This both advertises that we support four counters and enables them
because the pmu_num_counters() reads this value from PMCR.
Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20181211151945.29137-13-aaron@os.amperecomputing.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 35c105a..44f1340 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1777,7 +1777,7 @@
.access = PL1_W, .type = ARM_CP_NOP },
/* Performance monitors are implementation defined in v7,
* but with an ARM recommended set of registers, which we
- * follow (although we don't actually implement any counters)
+ * follow.
*
* Performance registers fall into three categories:
* (a) always UNDEF in PL0, RW in PL1 (PMINTENSET, PMINTENCLR)
@@ -5671,10 +5671,10 @@
}
if (arm_feature(env, ARM_FEATURE_V7)) {
/* v7 performance monitor control register: same implementor
- * field as main ID register, and we implement only the cycle
- * count register.
+ * field as main ID register, and we implement four counters in
+ * addition to the cycle count register.
*/
- unsigned int i, pmcrn = 0;
+ unsigned int i, pmcrn = 4;
ARMCPRegInfo pmcr = {
.name = "PMCR", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 0,
.access = PL0_RW,
@@ -5689,7 +5689,7 @@
.access = PL0_RW, .accessfn = pmreg_access,
.type = ARM_CP_IO,
.fieldoffset = offsetof(CPUARMState, cp15.c9_pmcr),
- .resetvalue = cpu->midr & 0xff000000,
+ .resetvalue = (cpu->midr & 0xff000000) | (pmcrn << PMCRN_SHIFT),
.writefn = pmcr_write, .raw_writefn = raw_write,
};
define_one_arm_cp_reg(cpu, &pmcr);
