target/arm: Make number of counters in PMCR follow the CPU

Currently we give all the v7-and-up CPUs a PMU with 4 counters.  This
means that we don't provide the 6 counters that are required by the
Arm BSA (Base System Architecture) specification if the CPU supports
the Virtualization extensions.

Instead of having a single PMCR_NUM_COUNTERS, make each CPU type
specify the PMCR reset value (obtained from the appropriate TRM), and
use the 'N' field of that value to define the number of counters
provided.

This means that we now supply 6 counters for Cortex-A53, A57, A72,
A15 and A9 as well as '-cpu max'; Cortex-A7 and A8 stay at 4; and
Cortex-R5 goes down to 3.

Note that because we now use the PMCR reset value of the specific
implementation, we no longer set the LC bit out of reset.  This has
an UNKNOWN value out of reset for all cores with any AArch32 support,
so guest software should be setting it anyway if it wants it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>
Message-id: 20210311165947.27470-1-peter.maydell@linaro.org
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 17 insertions, 12 deletions

diff --git a/target/arm/helper.c b/target/arm/helper.c
index d9220be7c5..8fb6cc96e4 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -38,7 +38,6 @@
 #endif
 
 #define ARM_CPU_FREQ 1000000000 /* FIXME: 1 GHz, should be configurable */
-#define PMCR_NUM_COUNTERS 4 /* QEMU IMPDEF choice */
 
 #ifndef CONFIG_USER_ONLY
 
@@ -1149,7 +1148,9 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
 
 static inline uint32_t pmu_num_counters(CPUARMState *env)
 {
-  return (env->cp15.c9_pmcr & PMCRN_MASK) >> PMCRN_SHIFT;
+    ARMCPU *cpu = env_archcpu(env);
+
+    return (cpu->isar.reset_pmcr_el0 & PMCRN_MASK) >> PMCRN_SHIFT;
 }
 
 /* Bits allowed to be set/cleared for PMCNTEN* and PMINTEN* */
@@ -5753,13 +5754,6 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
       .resetvalue = 0,
       .writefn = gt_hyp_ctl_write, .raw_writefn = raw_write },
 #endif
-    /* The only field of MDCR_EL2 that has a defined architectural reset value
-     * is MDCR_EL2.HPMN which should reset to the value of PMCR_EL0.N.
-     */
-    { .name = "MDCR_EL2", .state = ARM_CP_STATE_BOTH,
-      .opc0 = 3, .opc1 = 4, .crn = 1, .crm = 1, .opc2 = 1,
-      .access = PL2_RW, .resetvalue = PMCR_NUM_COUNTERS,
-      .fieldoffset = offsetof(CPUARMState, cp15.mdcr_el2), },
     { .name = "HPFAR", .state = ARM_CP_STATE_AA32,
       .cp = 15, .opc1 = 4, .crn = 6, .crm = 0, .opc2 = 4,
       .access = PL2_RW, .accessfn = access_el3_aa32ns,
@@ -6689,7 +6683,7 @@ static void define_pmu_regs(ARMCPU *cpu)
      * field as main ID register, and we implement four counters in
      * addition to the cycle count register.
      */
-    unsigned int i, pmcrn = PMCR_NUM_COUNTERS;
+    unsigned int i, pmcrn = pmu_num_counters(&cpu->env);
     ARMCPRegInfo pmcr = {
         .name = "PMCR", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 0,
         .access = PL0_RW,
@@ -6704,10 +6698,10 @@ static void define_pmu_regs(ARMCPU *cpu)
         .access = PL0_RW, .accessfn = pmreg_access,
         .type = ARM_CP_IO,
         .fieldoffset = offsetof(CPUARMState, cp15.c9_pmcr),
-        .resetvalue = (cpu->midr & 0xff000000) | (pmcrn << PMCRN_SHIFT) |
-                      PMCRLC,
+        .resetvalue = cpu->isar.reset_pmcr_el0,
         .writefn = pmcr_write, .raw_writefn = raw_write,
     };
+
     define_one_arm_cp_reg(cpu, &pmcr);
     define_one_arm_cp_reg(cpu, &pmcr64);
     for (i = 0; i < pmcrn; i++) {
@@ -7825,6 +7819,17 @@ void register_cp_regs_for_features(ARMCPU *cpu)
               .fieldoffset = offsetof(CPUARMState, cp15.vmpidr_el2) },
             REGINFO_SENTINEL
         };
+        /*
+         * The only field of MDCR_EL2 that has a defined architectural reset
+         * value is MDCR_EL2.HPMN which should reset to the value of PMCR_EL0.N.
+         */
+        ARMCPRegInfo mdcr_el2 = {
+            .name = "MDCR_EL2", .state = ARM_CP_STATE_BOTH,
+            .opc0 = 3, .opc1 = 4, .crn = 1, .crm = 1, .opc2 = 1,
+            .access = PL2_RW, .resetvalue = pmu_num_counters(env),
+            .fieldoffset = offsetof(CPUARMState, cp15.mdcr_el2),
+        };
+        define_one_arm_cp_reg(cpu, &mdcr_el2);
         define_arm_cp_regs(cpu, vpidr_regs);
         define_arm_cp_regs(cpu, el2_cp_reginfo);
         if (arm_feature(env, ARM_FEATURE_V8)) {