[PATCH v3 2/4] target/riscv: Add dummy mcountinhibit CSR for priv spec v1.11 or higher

[Anup Patel <apatel@ventanamicro.com>]

The mcountinhibit CSR is mandatory for priv spec v1.11 or higher. For
implementation that don't want to implement can simply have a dummy
mcountinhibit which always zero.

Fixes: a4b2fa433125 ("target/riscv: Introduce privilege version field in
the CSR ops.")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu_bits.h | 3 +++
 target/riscv/csr.c      | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 4d04b20d06..4a55c6a709 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -159,6 +159,9 @@
 #define CSR_MTVEC           0x305
 #define CSR_MCOUNTEREN      0x306
 
+/* Machine Counter Setup */
+#define CSR_MCOUNTINHIBIT   0x320
+
 /* 32-bit only */
 #define CSR_MSTATUSH        0x310
 
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 6dbe9b541f..409a209f14 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -3391,6 +3391,8 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_MIE]         = { "mie",        any,   NULL,    NULL,    rmw_mie           },
     [CSR_MTVEC]       = { "mtvec",      any,   read_mtvec,       write_mtvec       },
     [CSR_MCOUNTEREN]  = { "mcounteren", any,   read_mcounteren,  write_mcounteren  },
+    [CSR_MCOUNTINHIBIT] = { "mcountinhibit", any, read_zero, write_ignore,
+                                             .min_priv_ver = PRIV_VERSION_1_11_0 },
 
     [CSR_MSTATUSH]    = { "mstatush",   any32, read_mstatush,    write_mstatush    },
 
-- 
2.34.1