[PATCH 1/4] target/riscv: Add CSR tcontrol of debug trigger module

[Alvin Chang via <qemu-devel@nongnu.org>]

The RISC-V debug specification defines an optional CSR "tcontrol" within
the trigger module. This commit adds its read/write operations and
related bit-field definitions.

Signed-off-by: Alvin Chang <alvinga@andestech.com>
---
 target/riscv/cpu.h      |  1 +
 target/riscv/cpu_bits.h |  3 +++
 target/riscv/csr.c      | 15 +++++++++++++++
 3 files changed, 19 insertions(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index f52dce78ba..f9ae3e3025 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -364,6 +364,7 @@ struct CPUArchState {
     target_ulong tdata1[RV_MAX_TRIGGERS];
     target_ulong tdata2[RV_MAX_TRIGGERS];
     target_ulong tdata3[RV_MAX_TRIGGERS];
+    target_ulong tcontrol;
     target_ulong mcontext;
     struct CPUBreakpoint *cpu_breakpoint[RV_MAX_TRIGGERS];
     struct CPUWatchpoint *cpu_watchpoint[RV_MAX_TRIGGERS];
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index fc2068ee4d..3b3a7a0fa4 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -353,6 +353,7 @@
 #define CSR_TDATA2          0x7a2
 #define CSR_TDATA3          0x7a3
 #define CSR_TINFO           0x7a4
+#define CSR_TCONTROL        0x7a5
 #define CSR_MCONTEXT        0x7a8
 
 /* Debug Mode Registers */
@@ -900,6 +901,8 @@ typedef enum RISCVException {
 #define JVT_BASE                           (~0x3F)
 
 /* Debug Sdtrig CSR masks */
+#define TCONTROL_MTE                       BIT(3)
+#define TCONTROL_MPTE                      BIT(7)
 #define MCONTEXT32                         0x0000003F
 #define MCONTEXT64                         0x0000000000001FFFULL
 #define MCONTEXT32_HCONTEXT                0x0000007F
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index d4e8ac13b9..816c530481 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -3937,6 +3937,20 @@ static RISCVException read_tinfo(CPURISCVState *env, int csrno,
     return RISCV_EXCP_NONE;
 }
 
+static RISCVException read_tcontrol(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
+{
+    *val = env->tcontrol;
+    return RISCV_EXCP_NONE;
+}
+
+static RISCVException write_tcontrol(CPURISCVState *env, int csrno,
+                                     target_ulong val)
+{
+    env->tcontrol = val & (TCONTROL_MPTE | TCONTROL_MTE);
+    return RISCV_EXCP_NONE;
+}
+
 static RISCVException read_mcontext(CPURISCVState *env, int csrno,
                                     target_ulong *val)
 {
@@ -4861,6 +4875,7 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_TDATA2]    =  { "tdata2",   debug, read_tdata,    write_tdata    },
     [CSR_TDATA3]    =  { "tdata3",   debug, read_tdata,    write_tdata    },
     [CSR_TINFO]     =  { "tinfo",    debug, read_tinfo,    write_ignore   },
+    [CSR_TCONTROL]  =  { "tcontrol", debug, read_tcontrol, write_tcontrol },
     [CSR_MCONTEXT]  =  { "mcontext", debug, read_mcontext, write_mcontext },
 
     /* User Pointer Masking */
-- 
2.34.1