target/riscv: Add "pmu-mask" property to replace "pmu-num"

Using a mask instead of the number of PMU devices supports the accurate
emulation of platforms that have a discontinuous set of PMU counters.

The "pmu-num" property now generates a warning when used by the user on
the command line.

Rather than storing the value for "pmu-num" convert it directly to the
mask if it is specified (overwriting the default "pmu-mask" value)
likewise the value is calculated from the mask if the property value is
obtained.

In the unusual situation that both "pmu-mask" and "pmu-num" are provided
then then the order on the command line determines which takes
precedence (later overwriting earlier.)

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20231031154000.18134-5-rbradford@rivosinc.com>
[Changes by AF
 - Fixup ext_zihpm logic after rebase
]
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c
index 144bdac..08adad3 100644
--- a/target/riscv/tcg/tcg-cpu.c
+++ b/target/riscv/tcg/tcg-cpu.c
@@ -600,7 +600,7 @@ void riscv_cpu_validate_set_extensions(RISCVCPU *cpu, Error **errp)
     }
 
     if (!cpu->cfg.ext_zihpm) {
-        cpu->cfg.pmu_num = 0;
+        cpu->cfg.pmu_mask = 0;
         cpu->pmu_avail_ctrs = 0;
     }
 
@@ -688,7 +688,7 @@ static bool tcg_cpu_realize(CPUState *cs, Error **errp)
         riscv_timer_init(cpu);
     }
 
-    if (cpu->cfg.pmu_num) {
+    if (cpu->cfg.pmu_mask) {
         riscv_pmu_init(cpu, &local_err);
         if (local_err != NULL) {
             error_propagate(errp, local_err);