From 0a13a5b856ebb59dec6d165b87a0ba0e1e2dd952 Mon Sep 17 00:00:00 2001 From: Alistair Francis Date: Mon, 17 Jun 2019 18:31:22 -0700 Subject: [PATCH] target/riscv: Add support for disabling/enabling Counters Add support for disabling/enabling the "Counters" extension. Signed-off-by: Alistair Francis Reviewed-by: Palmer Dabbelt Signed-off-by: Palmer Dabbelt --- target/riscv/cpu.c | 1 + target/riscv/cpu.h | 1 + target/riscv/csr.c | 17 ++++++++++++----- 3 files changed, 14 insertions(+), 5 deletions(-) diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index 6a54ebf10c..be90fa7d08 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -440,6 +440,7 @@ static Property riscv_cpu_properties[] = { DEFINE_PROP_BOOL("c", RISCVCPU, cfg.ext_c, true), DEFINE_PROP_BOOL("s", RISCVCPU, cfg.ext_s, true), DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true), + DEFINE_PROP_BOOL("Counters", RISCVCPU, cfg.ext_counters, true), DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec), DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true), DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true), diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index 0855277b92..4d4e0f89e2 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -222,6 +222,7 @@ typedef struct RISCVCPU { bool ext_c; bool ext_s; bool ext_u; + bool ext_counters; char *priv_spec; char *user_spec; diff --git a/target/riscv/csr.c b/target/riscv/csr.c index 448162e484..de67741f36 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -56,17 +56,24 @@ static int fs(CPURISCVState *env, int csrno) static int ctr(CPURISCVState *env, int csrno) { #if !defined(CONFIG_USER_ONLY) + CPUState *cs = env_cpu(env); + RISCVCPU *cpu = RISCV_CPU(cs); + uint32_t ctr_en = ~0u; + + if (!cpu->cfg.ext_counters) { + /* The Counters extensions is not enabled */ + return -1; + } + /* - * The counters are always enabled on newer priv specs, as the CSR has - * changed from controlling that the counters can be read to controlling - * that the counters increment. + * The counters are always enabled at run time on newer priv specs, as the + * CSR has changed from controlling that the counters can be read to + * controlling that the counters increment. */ if (env->priv_ver > PRIV_VERSION_1_09_1) { return 0; } - uint32_t ctr_en = ~0u; - if (env->priv < PRV_M) { ctr_en &= env->mcounteren; } -- 2.11.4.GIT