Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Atish Patra <atishp@rivosinc.com>
To:     linux-kernel@vger.kernel.org
Cc:     Bin Meng <bmeng.cn@gmail.com>,
        Alistair Francis <alistair.francis@wdc.com>,
        Atish Patra <atishp@rivosinc.com>,
        Bin Meng <bin.meng@windriver.com>,
        Palmer Dabbelt <palmer@dabbelt.com>, qemu-devel@nongnu.org,
        qemu-riscv@nongnu.org
Subject: [PATCH v8 04/12] target/riscv: pmu: Make number of counters configurable
Date:   Wed, 11 May 2022 14:59:48 -0700
Message-Id: <20220511215956.2351243-5-atishp@rivosinc.com>
In-Reply-To: <20220511215956.2351243-1-atishp@rivosinc.com>
References: <20220511215956.2351243-1-atishp@rivosinc.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The RISC-V privilege specification provides flexibility to implement
any number of counters from 29 programmable counters. However, the QEMU
implements all the counters.

Make it configurable through pmu config parameter which now will indicate
how many programmable counters should be implemented by the cpu.

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 target/riscv/cpu.c |  2 +-
 target/riscv/cpu.h |  2 +-
 target/riscv/csr.c | 94 ++++++++++++++++++++++++++++++----------------
 3 files changed, 63 insertions(+), 35 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 5ad17b40189f..2dc4b500797d 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -822,7 +822,7 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true),
     DEFINE_PROP_BOOL("v", RISCVCPU, cfg.ext_v, false),
     DEFINE_PROP_BOOL("h", RISCVCPU, cfg.ext_h, true),
-    DEFINE_PROP_BOOL("pmu", RISCVCPU, cfg.ext_pmu, true),
+    DEFINE_PROP_UINT8("pmu-num", RISCVCPU, cfg.pmu_num, 16),
     DEFINE_PROP_BOOL("Zifencei", RISCVCPU, cfg.ext_ifencei, true),
     DEFINE_PROP_BOOL("Zicsr", RISCVCPU, cfg.ext_icsr, true),
     DEFINE_PROP_BOOL("Zfh", RISCVCPU, cfg.ext_zfh, false),
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 09a0c71093c5..7cbcd8d62fc1 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -391,7 +391,6 @@ struct RISCVCPUConfig {
     bool ext_zksed;
     bool ext_zksh;
     bool ext_zkt;
-    bool ext_pmu;
     bool ext_ifencei;
     bool ext_icsr;
     bool ext_svinval;
@@ -413,6 +412,7 @@ struct RISCVCPUConfig {
     /* Vendor-specific custom extensions */
     bool ext_XVentanaCondOps;
 
+    uint8_t pmu_num;
     char *priv_spec;
     char *user_spec;
     char *bext_spec;
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index c625b17dd58e..7e14f7685fb9 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -73,9 +73,17 @@ static RISCVException ctr(CPURISCVState *env, int csrno)
     CPUState *cs = env_cpu(env);
     RISCVCPU *cpu = RISCV_CPU(cs);
     int ctr_index;
+    int base_csrno = CSR_HPMCOUNTER3;
+    bool rv32 = riscv_cpu_mxl(env) == MXL_RV32 ? true : false;
 
-    if (!cpu->cfg.ext_pmu) {
-        /* The PMU extension is not enabled */
+    if (rv32 && csrno >= CSR_CYCLEH) {
+        /* Offset for RV32 hpmcounternh counters */
+        base_csrno += 0x80;
+    }
+    ctr_index = csrno - base_csrno;
+
+    if (!cpu->cfg.pmu_num || ctr_index >= (cpu->cfg.pmu_num)) {
+        /* No counter is enabled in PMU or the counter is out of range */
         return RISCV_EXCP_ILLEGAL_INST;
     }
 
@@ -103,7 +111,7 @@ static RISCVException ctr(CPURISCVState *env, int csrno)
             }
             break;
         }
-        if (riscv_cpu_mxl(env) == MXL_RV32) {
+        if (rv32) {
             switch (csrno) {
             case CSR_CYCLEH:
                 if (!get_field(env->mcounteren, COUNTEREN_CY)) {
@@ -158,7 +166,7 @@ static RISCVException ctr(CPURISCVState *env, int csrno)
             }
             break;
         }
-        if (riscv_cpu_mxl(env) == MXL_RV32) {
+        if (rv32) {
             switch (csrno) {
             case CSR_CYCLEH:
                 if (!get_field(env->hcounteren, COUNTEREN_CY) &&
@@ -202,6 +210,26 @@ static RISCVException ctr32(CPURISCVState *env, int csrno)
 }
 
 #if !defined(CONFIG_USER_ONLY)
+static RISCVException mctr(CPURISCVState *env, int csrno)
+{
+    CPUState *cs = env_cpu(env);
+    RISCVCPU *cpu = RISCV_CPU(cs);
+    int ctr_index;
+    int base_csrno = CSR_MHPMCOUNTER3;
+
+    if ((riscv_cpu_mxl(env) == MXL_RV32) && csrno >= CSR_MCYCLEH) {
+        /* Offset for RV32 mhpmcounternh counters */
+        base_csrno += 0x80;
+    }
+    ctr_index = csrno - base_csrno;
+    if (!cpu->cfg.pmu_num || ctr_index >= cpu->cfg.pmu_num) {
+        /* The PMU is not enabled or counter is out of range*/
+        return RISCV_EXCP_ILLEGAL_INST;
+    }
+
+    return RISCV_EXCP_NONE;
+}
+
 static RISCVException any(CPURISCVState *env, int csrno)
 {
     return RISCV_EXCP_NONE;
@@ -3683,35 +3711,35 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_HPMCOUNTER30]   = { "hpmcounter30",   ctr,    read_zero },
     [CSR_HPMCOUNTER31]   = { "hpmcounter31",   ctr,    read_zero },
 
-    [CSR_MHPMCOUNTER3]   = { "mhpmcounter3",   any,    read_zero },
-    [CSR_MHPMCOUNTER4]   = { "mhpmcounter4",   any,    read_zero },
-    [CSR_MHPMCOUNTER5]   = { "mhpmcounter5",   any,    read_zero },
-    [CSR_MHPMCOUNTER6]   = { "mhpmcounter6",   any,    read_zero },
-    [CSR_MHPMCOUNTER7]   = { "mhpmcounter7",   any,    read_zero },
-    [CSR_MHPMCOUNTER8]   = { "mhpmcounter8",   any,    read_zero },
-    [CSR_MHPMCOUNTER9]   = { "mhpmcounter9",   any,    read_zero },
-    [CSR_MHPMCOUNTER10]  = { "mhpmcounter10",  any,    read_zero },
-    [CSR_MHPMCOUNTER11]  = { "mhpmcounter11",  any,    read_zero },
-    [CSR_MHPMCOUNTER12]  = { "mhpmcounter12",  any,    read_zero },
-    [CSR_MHPMCOUNTER13]  = { "mhpmcounter13",  any,    read_zero },
-    [CSR_MHPMCOUNTER14]  = { "mhpmcounter14",  any,    read_zero },
-    [CSR_MHPMCOUNTER15]  = { "mhpmcounter15",  any,    read_zero },
-    [CSR_MHPMCOUNTER16]  = { "mhpmcounter16",  any,    read_zero },
-    [CSR_MHPMCOUNTER17]  = { "mhpmcounter17",  any,    read_zero },
-    [CSR_MHPMCOUNTER18]  = { "mhpmcounter18",  any,    read_zero },
-    [CSR_MHPMCOUNTER19]  = { "mhpmcounter19",  any,    read_zero },
-    [CSR_MHPMCOUNTER20]  = { "mhpmcounter20",  any,    read_zero },
-    [CSR_MHPMCOUNTER21]  = { "mhpmcounter21",  any,    read_zero },
-    [CSR_MHPMCOUNTER22]  = { "mhpmcounter22",  any,    read_zero },
-    [CSR_MHPMCOUNTER23]  = { "mhpmcounter23",  any,    read_zero },
-    [CSR_MHPMCOUNTER24]  = { "mhpmcounter24",  any,    read_zero },
-    [CSR_MHPMCOUNTER25]  = { "mhpmcounter25",  any,    read_zero },
-    [CSR_MHPMCOUNTER26]  = { "mhpmcounter26",  any,    read_zero },
-    [CSR_MHPMCOUNTER27]  = { "mhpmcounter27",  any,    read_zero },
-    [CSR_MHPMCOUNTER28]  = { "mhpmcounter28",  any,    read_zero },
-    [CSR_MHPMCOUNTER29]  = { "mhpmcounter29",  any,    read_zero },
-    [CSR_MHPMCOUNTER30]  = { "mhpmcounter30",  any,    read_zero },
-    [CSR_MHPMCOUNTER31]  = { "mhpmcounter31",  any,    read_zero },
+    [CSR_MHPMCOUNTER3]   = { "mhpmcounter3",   mctr,   read_zero },
+    [CSR_MHPMCOUNTER4]   = { "mhpmcounter4",   mctr,   read_zero },
+    [CSR_MHPMCOUNTER5]   = { "mhpmcounter5",   mctr,   read_zero },
+    [CSR_MHPMCOUNTER6]   = { "mhpmcounter6",   mctr,   read_zero },
+    [CSR_MHPMCOUNTER7]   = { "mhpmcounter7",   mctr,   read_zero },
+    [CSR_MHPMCOUNTER8]   = { "mhpmcounter8",   mctr,   read_zero },
+    [CSR_MHPMCOUNTER9]   = { "mhpmcounter9",   mctr,   read_zero },
+    [CSR_MHPMCOUNTER10]  = { "mhpmcounter10",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER11]  = { "mhpmcounter11",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER12]  = { "mhpmcounter12",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER13]  = { "mhpmcounter13",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER14]  = { "mhpmcounter14",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER15]  = { "mhpmcounter15",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER16]  = { "mhpmcounter16",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER17]  = { "mhpmcounter17",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER18]  = { "mhpmcounter18",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER19]  = { "mhpmcounter19",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER20]  = { "mhpmcounter20",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER21]  = { "mhpmcounter21",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER22]  = { "mhpmcounter22",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER23]  = { "mhpmcounter23",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER24]  = { "mhpmcounter24",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER25]  = { "mhpmcounter25",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER26]  = { "mhpmcounter26",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER27]  = { "mhpmcounter27",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER28]  = { "mhpmcounter28",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER29]  = { "mhpmcounter29",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER30]  = { "mhpmcounter30",  mctr,   read_zero },
+    [CSR_MHPMCOUNTER31]  = { "mhpmcounter31",  mctr,   read_zero },
 
     [CSR_MHPMEVENT3]     = { "mhpmevent3",     any,    read_zero },
     [CSR_MHPMEVENT4]     = { "mhpmevent4",     any,    read_zero },
-- 
2.25.1