[PATCH v1 0/5] RISC-V: Convert the CSR access functions to use

[PATCH v1 0/5] RISC-V: Convert the CSR access functions to use

[Alistair Francis]

Alistair Francis (5):
  target/riscv: Convert the RISC-V exceptions to an enum
  target/riscv: Use the RiscVException enum for CSR predicates
  target/riscv: Fix 32-bit HS mode access permissions
  target/riscv: Use the RiscVException enum for CSR operations
  target/riscv: Use RiscVException enum for CSR access

 target/riscv/cpu.h        |  28 +-
 target/riscv/cpu_bits.h   |  44 +--
 target/riscv/cpu.c        |   2 +-
 target/riscv/cpu_helper.c |   4 +-
 target/riscv/csr.c        | 753 ++++++++++++++++++++++----------------
 target/riscv/gdbstub.c    |   8 +-
 target/riscv/op_helper.c  |  18 +-
 7 files changed, 499 insertions(+), 358 deletions(-)

-- 
2.30.1

[PATCH v1 1/5] target/riscv: Convert the RISC-V exceptions to an enum

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu_bits.h   | 44 ++++++++++++++++++++-------------------
 target/riscv/cpu.c        |  2 +-
 target/riscv/cpu_helper.c |  4 ++--
 3 files changed, 26 insertions(+), 24 deletions(-)

diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index caf4599207..8ae404c32a 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -527,27 +527,29 @@
 #define DEFAULT_RSTVEC      0x1000
 
 /* Exception causes */
-#define EXCP_NONE                                -1 /* sentinel value */
-#define RISCV_EXCP_INST_ADDR_MIS                 0x0
-#define RISCV_EXCP_INST_ACCESS_FAULT             0x1
-#define RISCV_EXCP_ILLEGAL_INST                  0x2
-#define RISCV_EXCP_BREAKPOINT                    0x3
-#define RISCV_EXCP_LOAD_ADDR_MIS                 0x4
-#define RISCV_EXCP_LOAD_ACCESS_FAULT             0x5
-#define RISCV_EXCP_STORE_AMO_ADDR_MIS            0x6
-#define RISCV_EXCP_STORE_AMO_ACCESS_FAULT        0x7
-#define RISCV_EXCP_U_ECALL                       0x8
-#define RISCV_EXCP_S_ECALL                      0x9
-#define RISCV_EXCP_VS_ECALL                      0xa
-#define RISCV_EXCP_M_ECALL                       0xb
-#define RISCV_EXCP_INST_PAGE_FAULT               0xc /* since: priv-1.10.0 */
-#define RISCV_EXCP_LOAD_PAGE_FAULT               0xd /* since: priv-1.10.0 */
-#define RISCV_EXCP_STORE_PAGE_FAULT              0xf /* since: priv-1.10.0 */
-#define RISCV_EXCP_SEMIHOST                      0x10
-#define RISCV_EXCP_INST_GUEST_PAGE_FAULT         0x14
-#define RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT       0x15
-#define RISCV_EXCP_VIRT_INSTRUCTION_FAULT        0x16
-#define RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT  0x17
+typedef enum RiscVException {
+    RISCV_EXCP_NONE = -1, /* sentinel value */
+    RISCV_EXCP_INST_ADDR_MIS = 0x0,
+    RISCV_EXCP_INST_ACCESS_FAULT = 0x1,
+    RISCV_EXCP_ILLEGAL_INST = 0x2,
+    RISCV_EXCP_BREAKPOINT = 0x3,
+    RISCV_EXCP_LOAD_ADDR_MIS = 0x4,
+    RISCV_EXCP_LOAD_ACCESS_FAULT = 0x5,
+    RISCV_EXCP_STORE_AMO_ADDR_MIS = 0x6,
+    RISCV_EXCP_STORE_AMO_ACCESS_FAULT = 0x7,
+    RISCV_EXCP_U_ECALL = 0x8,
+    RISCV_EXCP_S_ECALL = 0x9,
+    RISCV_EXCP_VS_ECALL = 0xa,
+    RISCV_EXCP_M_ECALL = 0xb,
+    RISCV_EXCP_INST_PAGE_FAULT = 0xc, /* since: priv-1.10.0 */
+    RISCV_EXCP_LOAD_PAGE_FAULT = 0xd, /* since: priv-1.10.0 */
+    RISCV_EXCP_STORE_PAGE_FAULT = 0xf, /* since: priv-1.10.0 */
+    RISCV_EXCP_SEMIHOST = 0x10,
+    RISCV_EXCP_INST_GUEST_PAGE_FAULT = 0x14,
+    RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT = 0x15,
+    RISCV_EXCP_VIRT_INSTRUCTION_FAULT = 0x16,
+    RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT = 0x17,
+} RiscVException;
 
 #define RISCV_EXCP_INT_FLAG                0x80000000
 #define RISCV_EXCP_INT_MASK                0x7fffffff
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 2a990f6253..63584b4a20 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -357,7 +357,7 @@ static void riscv_cpu_reset(DeviceState *dev)
     env->mcause = 0;
     env->pc = env->resetvec;
 #endif
-    cs->exception_index = EXCP_NONE;
+    cs->exception_index = RISCV_EXCP_NONE;
     env->load_res = -1;
     set_default_nan_mode(1, &env->fp_status);
 }
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 83a6bcfad0..af702f65b1 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -72,7 +72,7 @@ static int riscv_cpu_local_irq_pending(CPURISCVState *env)
     if (irqs) {
         return ctz64(irqs); /* since non-zero */
     } else {
-        return EXCP_NONE; /* indicates no pending interrupt */
+        return RISCV_EXCP_NONE; /* indicates no pending interrupt */
     }
 }
 #endif
@@ -1017,5 +1017,5 @@ void riscv_cpu_do_interrupt(CPUState *cs)
      */
 
 #endif
-    cs->exception_index = EXCP_NONE; /* mark handled to qemu */
+    cs->exception_index = RISCV_EXCP_NONE; /* mark handled to qemu */
 }
-- 
2.30.1

Re: [PATCH v1 1/5] target/riscv: Convert the RISC-V exceptions to an enum

[Bin Meng]

On Thu, Mar 18, 2021 at 1:41 AM Alistair Francis
<alistair.francis@wdc.com> wrote:
>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu_bits.h   | 44 ++++++++++++++++++++-------------------
>  target/riscv/cpu.c        |  2 +-
>  target/riscv/cpu_helper.c |  4 ++--
>  3 files changed, 26 insertions(+), 24 deletions(-)
>
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index caf4599207..8ae404c32a 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -527,27 +527,29 @@
>  #define DEFAULT_RSTVEC      0x1000
>
>  /* Exception causes */
> -#define EXCP_NONE                                -1 /* sentinel value */
> -#define RISCV_EXCP_INST_ADDR_MIS                 0x0
> -#define RISCV_EXCP_INST_ACCESS_FAULT             0x1
> -#define RISCV_EXCP_ILLEGAL_INST                  0x2
> -#define RISCV_EXCP_BREAKPOINT                    0x3
> -#define RISCV_EXCP_LOAD_ADDR_MIS                 0x4
> -#define RISCV_EXCP_LOAD_ACCESS_FAULT             0x5
> -#define RISCV_EXCP_STORE_AMO_ADDR_MIS            0x6
> -#define RISCV_EXCP_STORE_AMO_ACCESS_FAULT        0x7
> -#define RISCV_EXCP_U_ECALL                       0x8
> -#define RISCV_EXCP_S_ECALL                      0x9
> -#define RISCV_EXCP_VS_ECALL                      0xa
> -#define RISCV_EXCP_M_ECALL                       0xb
> -#define RISCV_EXCP_INST_PAGE_FAULT               0xc /* since: priv-1.10.0 */
> -#define RISCV_EXCP_LOAD_PAGE_FAULT               0xd /* since: priv-1.10.0 */
> -#define RISCV_EXCP_STORE_PAGE_FAULT              0xf /* since: priv-1.10.0 */
> -#define RISCV_EXCP_SEMIHOST                      0x10
> -#define RISCV_EXCP_INST_GUEST_PAGE_FAULT         0x14
> -#define RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT       0x15
> -#define RISCV_EXCP_VIRT_INSTRUCTION_FAULT        0x16
> -#define RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT  0x17
> +typedef enum RiscVException {

nits: looking at other places in the RISC-V codes, I believe it's
better to name it "RISCVException"

> +    RISCV_EXCP_NONE = -1, /* sentinel value */
> +    RISCV_EXCP_INST_ADDR_MIS = 0x0,
> +    RISCV_EXCP_INST_ACCESS_FAULT = 0x1,
> +    RISCV_EXCP_ILLEGAL_INST = 0x2,
> +    RISCV_EXCP_BREAKPOINT = 0x3,
> +    RISCV_EXCP_LOAD_ADDR_MIS = 0x4,
> +    RISCV_EXCP_LOAD_ACCESS_FAULT = 0x5,
> +    RISCV_EXCP_STORE_AMO_ADDR_MIS = 0x6,
> +    RISCV_EXCP_STORE_AMO_ACCESS_FAULT = 0x7,
> +    RISCV_EXCP_U_ECALL = 0x8,
> +    RISCV_EXCP_S_ECALL = 0x9,
> +    RISCV_EXCP_VS_ECALL = 0xa,
> +    RISCV_EXCP_M_ECALL = 0xb,
> +    RISCV_EXCP_INST_PAGE_FAULT = 0xc, /* since: priv-1.10.0 */
> +    RISCV_EXCP_LOAD_PAGE_FAULT = 0xd, /* since: priv-1.10.0 */
> +    RISCV_EXCP_STORE_PAGE_FAULT = 0xf, /* since: priv-1.10.0 */
> +    RISCV_EXCP_SEMIHOST = 0x10,
> +    RISCV_EXCP_INST_GUEST_PAGE_FAULT = 0x14,
> +    RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT = 0x15,
> +    RISCV_EXCP_VIRT_INSTRUCTION_FAULT = 0x16,
> +    RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT = 0x17,
> +} RiscVException;
>
>  #define RISCV_EXCP_INT_FLAG                0x80000000
>  #define RISCV_EXCP_INT_MASK                0x7fffffff
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 2a990f6253..63584b4a20 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -357,7 +357,7 @@ static void riscv_cpu_reset(DeviceState *dev)
>      env->mcause = 0;
>      env->pc = env->resetvec;
>  #endif
> -    cs->exception_index = EXCP_NONE;
> +    cs->exception_index = RISCV_EXCP_NONE;
>      env->load_res = -1;
>      set_default_nan_mode(1, &env->fp_status);
>  }
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 83a6bcfad0..af702f65b1 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -72,7 +72,7 @@ static int riscv_cpu_local_irq_pending(CPURISCVState *env)
>      if (irqs) {
>          return ctz64(irqs); /* since non-zero */
>      } else {
> -        return EXCP_NONE; /* indicates no pending interrupt */
> +        return RISCV_EXCP_NONE; /* indicates no pending interrupt */
>      }
>  }
>  #endif
> @@ -1017,5 +1017,5 @@ void riscv_cpu_do_interrupt(CPUState *cs)
>       */
>
>  #endif
> -    cs->exception_index = EXCP_NONE; /* mark handled to qemu */
> +    cs->exception_index = RISCV_EXCP_NONE; /* mark handled to qemu */
>  }
> --

Otherwise,
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

Re: [PATCH v1 1/5] target/riscv: Convert the RISC-V exceptions to an enum

[Alistair Francis]

On Wed, Mar 17, 2021 at 9:58 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> On Thu, Mar 18, 2021 at 1:41 AM Alistair Francis
> <alistair.francis@wdc.com> wrote:
> >
> > Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> > ---
> >  target/riscv/cpu_bits.h   | 44 ++++++++++++++++++++-------------------
> >  target/riscv/cpu.c        |  2 +-
> >  target/riscv/cpu_helper.c |  4 ++--
> >  3 files changed, 26 insertions(+), 24 deletions(-)
> >
> > diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> > index caf4599207..8ae404c32a 100644
> > --- a/target/riscv/cpu_bits.h
> > +++ b/target/riscv/cpu_bits.h
> > @@ -527,27 +527,29 @@
> >  #define DEFAULT_RSTVEC      0x1000
> >
> >  /* Exception causes */
> > -#define EXCP_NONE                                -1 /* sentinel value */
> > -#define RISCV_EXCP_INST_ADDR_MIS                 0x0
> > -#define RISCV_EXCP_INST_ACCESS_FAULT             0x1
> > -#define RISCV_EXCP_ILLEGAL_INST                  0x2
> > -#define RISCV_EXCP_BREAKPOINT                    0x3
> > -#define RISCV_EXCP_LOAD_ADDR_MIS                 0x4
> > -#define RISCV_EXCP_LOAD_ACCESS_FAULT             0x5
> > -#define RISCV_EXCP_STORE_AMO_ADDR_MIS            0x6
> > -#define RISCV_EXCP_STORE_AMO_ACCESS_FAULT        0x7
> > -#define RISCV_EXCP_U_ECALL                       0x8
> > -#define RISCV_EXCP_S_ECALL                      0x9
> > -#define RISCV_EXCP_VS_ECALL                      0xa
> > -#define RISCV_EXCP_M_ECALL                       0xb
> > -#define RISCV_EXCP_INST_PAGE_FAULT               0xc /* since: priv-1.10.0 */
> > -#define RISCV_EXCP_LOAD_PAGE_FAULT               0xd /* since: priv-1.10.0 */
> > -#define RISCV_EXCP_STORE_PAGE_FAULT              0xf /* since: priv-1.10.0 */
> > -#define RISCV_EXCP_SEMIHOST                      0x10
> > -#define RISCV_EXCP_INST_GUEST_PAGE_FAULT         0x14
> > -#define RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT       0x15
> > -#define RISCV_EXCP_VIRT_INSTRUCTION_FAULT        0x16
> > -#define RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT  0x17
> > +typedef enum RiscVException {
>
> nits: looking at other places in the RISC-V codes, I believe it's
> better to name it "RISCVException"

I agree, I have fixed the name.

>
> > +    RISCV_EXCP_NONE = -1, /* sentinel value */
> > +    RISCV_EXCP_INST_ADDR_MIS = 0x0,
> > +    RISCV_EXCP_INST_ACCESS_FAULT = 0x1,
> > +    RISCV_EXCP_ILLEGAL_INST = 0x2,
> > +    RISCV_EXCP_BREAKPOINT = 0x3,
> > +    RISCV_EXCP_LOAD_ADDR_MIS = 0x4,
> > +    RISCV_EXCP_LOAD_ACCESS_FAULT = 0x5,
> > +    RISCV_EXCP_STORE_AMO_ADDR_MIS = 0x6,
> > +    RISCV_EXCP_STORE_AMO_ACCESS_FAULT = 0x7,
> > +    RISCV_EXCP_U_ECALL = 0x8,
> > +    RISCV_EXCP_S_ECALL = 0x9,
> > +    RISCV_EXCP_VS_ECALL = 0xa,
> > +    RISCV_EXCP_M_ECALL = 0xb,
> > +    RISCV_EXCP_INST_PAGE_FAULT = 0xc, /* since: priv-1.10.0 */
> > +    RISCV_EXCP_LOAD_PAGE_FAULT = 0xd, /* since: priv-1.10.0 */
> > +    RISCV_EXCP_STORE_PAGE_FAULT = 0xf, /* since: priv-1.10.0 */
> > +    RISCV_EXCP_SEMIHOST = 0x10,
> > +    RISCV_EXCP_INST_GUEST_PAGE_FAULT = 0x14,
> > +    RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT = 0x15,
> > +    RISCV_EXCP_VIRT_INSTRUCTION_FAULT = 0x16,
> > +    RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT = 0x17,
> > +} RiscVException;
> >
> >  #define RISCV_EXCP_INT_FLAG                0x80000000
> >  #define RISCV_EXCP_INT_MASK                0x7fffffff
> > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> > index 2a990f6253..63584b4a20 100644
> > --- a/target/riscv/cpu.c
> > +++ b/target/riscv/cpu.c
> > @@ -357,7 +357,7 @@ static void riscv_cpu_reset(DeviceState *dev)
> >      env->mcause = 0;
> >      env->pc = env->resetvec;
> >  #endif
> > -    cs->exception_index = EXCP_NONE;
> > +    cs->exception_index = RISCV_EXCP_NONE;
> >      env->load_res = -1;
> >      set_default_nan_mode(1, &env->fp_status);
> >  }
> > diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> > index 83a6bcfad0..af702f65b1 100644
> > --- a/target/riscv/cpu_helper.c
> > +++ b/target/riscv/cpu_helper.c
> > @@ -72,7 +72,7 @@ static int riscv_cpu_local_irq_pending(CPURISCVState *env)
> >      if (irqs) {
> >          return ctz64(irqs); /* since non-zero */
> >      } else {
> > -        return EXCP_NONE; /* indicates no pending interrupt */
> > +        return RISCV_EXCP_NONE; /* indicates no pending interrupt */
> >      }
> >  }
> >  #endif
> > @@ -1017,5 +1017,5 @@ void riscv_cpu_do_interrupt(CPUState *cs)
> >       */
> >
> >  #endif
> > -    cs->exception_index = EXCP_NONE; /* mark handled to qemu */
> > +    cs->exception_index = RISCV_EXCP_NONE; /* mark handled to qemu */
> >  }
> > --
>
> Otherwise,
> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

Thanks!

Alistair

[PATCH v1 2/5] target/riscv: Use the RiscVException enum for CSR predicates

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.h |  3 +-
 target/riscv/csr.c | 80 +++++++++++++++++++++++++---------------------
 2 files changed, 46 insertions(+), 37 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 0edb2826a2..073a994d13 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -469,7 +469,8 @@ static inline target_ulong riscv_csr_read(CPURISCVState *env, int csrno)
     return val;
 }
 
-typedef int (*riscv_csr_predicate_fn)(CPURISCVState *env, int csrno);
+typedef RiscVException (*riscv_csr_predicate_fn)(CPURISCVState *env,
+                                                 int csrno);
 typedef int (*riscv_csr_read_fn)(CPURISCVState *env, int csrno,
     target_ulong *ret_value);
 typedef int (*riscv_csr_write_fn)(CPURISCVState *env, int csrno,
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index fd2e6363f3..da9baff6fb 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -35,29 +35,29 @@ void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops)
 }
 
 /* Predicates */
-static int fs(CPURISCVState *env, int csrno)
+static RiscVException fs(CPURISCVState *env, int csrno)
 {
 #if !defined(CONFIG_USER_ONLY)
     /* loose check condition for fcsr in vector extension */
     if ((csrno == CSR_FCSR) && (env->misa & RVV)) {
-        return 0;
+        return RISCV_EXCP_INST_ACCESS_FAULT;
     }
     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 #endif
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int vs(CPURISCVState *env, int csrno)
+static RiscVException vs(CPURISCVState *env, int csrno)
 {
     if (env->misa & RVV) {
-        return 0;
+        return RISCV_EXCP_NONE;
     }
-    return -1;
+    return RISCV_EXCP_INST_ACCESS_FAULT;
 }
 
-static int ctr(CPURISCVState *env, int csrno)
+static RiscVException ctr(CPURISCVState *env, int csrno)
 {
 #if !defined(CONFIG_USER_ONLY)
     CPUState *cs = env_cpu(env);
@@ -65,7 +65,7 @@ static int ctr(CPURISCVState *env, int csrno)
 
     if (!cpu->cfg.ext_counters) {
         /* The Counters extensions is not enabled */
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     if (riscv_cpu_virt_enabled(env)) {
@@ -73,25 +73,25 @@ static int ctr(CPURISCVState *env, int csrno)
         case CSR_CYCLE:
             if (!get_field(env->hcounteren, HCOUNTEREN_CY) &&
                 get_field(env->mcounteren, HCOUNTEREN_CY)) {
-                return -RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+                return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
             }
             break;
         case CSR_TIME:
             if (!get_field(env->hcounteren, HCOUNTEREN_TM) &&
                 get_field(env->mcounteren, HCOUNTEREN_TM)) {
-                return -RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+                return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
             }
             break;
         case CSR_INSTRET:
             if (!get_field(env->hcounteren, HCOUNTEREN_IR) &&
                 get_field(env->mcounteren, HCOUNTEREN_IR)) {
-                return -RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+                return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
             }
             break;
         case CSR_HPMCOUNTER3...CSR_HPMCOUNTER31:
             if (!get_field(env->hcounteren, 1 << (csrno - CSR_HPMCOUNTER3)) &&
                 get_field(env->mcounteren, 1 << (csrno - CSR_HPMCOUNTER3))) {
-                return -RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+                return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
             }
             break;
         }
@@ -100,93 +100,101 @@ static int ctr(CPURISCVState *env, int csrno)
             case CSR_CYCLEH:
                 if (!get_field(env->hcounteren, HCOUNTEREN_CY) &&
                     get_field(env->mcounteren, HCOUNTEREN_CY)) {
-                    return -RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+                    return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
                 }
                 break;
             case CSR_TIMEH:
                 if (!get_field(env->hcounteren, HCOUNTEREN_TM) &&
                     get_field(env->mcounteren, HCOUNTEREN_TM)) {
-                    return -RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+                    return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
                 }
                 break;
             case CSR_INSTRETH:
                 if (!get_field(env->hcounteren, HCOUNTEREN_IR) &&
                     get_field(env->mcounteren, HCOUNTEREN_IR)) {
-                    return -RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+                    return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
                 }
                 break;
             case CSR_HPMCOUNTER3H...CSR_HPMCOUNTER31H:
                 if (!get_field(env->hcounteren, 1 << (csrno - CSR_HPMCOUNTER3H)) &&
                     get_field(env->mcounteren, 1 << (csrno - CSR_HPMCOUNTER3H))) {
-                    return -RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+                    return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
                 }
                 break;
             }
         }
     }
 #endif
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int ctr32(CPURISCVState *env, int csrno)
+static RiscVException ctr32(CPURISCVState *env, int csrno)
 {
     if (!riscv_cpu_is_32bit(env)) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     return ctr(env, csrno);
 }
 
 #if !defined(CONFIG_USER_ONLY)
-static int any(CPURISCVState *env, int csrno)
+static RiscVException any(CPURISCVState *env, int csrno)
 {
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int any32(CPURISCVState *env, int csrno)
+static RiscVException any32(CPURISCVState *env, int csrno)
 {
     if (!riscv_cpu_is_32bit(env)) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     return any(env, csrno);
 
 }
 
-static int smode(CPURISCVState *env, int csrno)
+static RiscVException smode(CPURISCVState *env, int csrno)
 {
-    return -!riscv_has_ext(env, RVS);
+    if (riscv_has_ext(env, RVS)) {
+        return RISCV_EXCP_NONE;
+    }
+
+    return RISCV_EXCP_ILLEGAL_INST;
 }
 
-static int hmode(CPURISCVState *env, int csrno)
+static RiscVException hmode(CPURISCVState *env, int csrno)
 {
     if (riscv_has_ext(env, RVS) &&
         riscv_has_ext(env, RVH)) {
         /* Hypervisor extension is supported */
         if ((env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) ||
             env->priv == PRV_M) {
-            return 0;
+            return RISCV_EXCP_NONE;
         } else {
-            return -RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+            return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
         }
     }
 
-    return -RISCV_EXCP_ILLEGAL_INST;
+    return RISCV_EXCP_ILLEGAL_INST;
 }
 
-static int hmode32(CPURISCVState *env, int csrno)
+static RiscVException hmode32(CPURISCVState *env, int csrno)
 {
     if (!riscv_cpu_is_32bit(env)) {
-        return 0;
+        return RISCV_EXCP_NONE;
     }
 
     return hmode(env, csrno);
 
 }
 
-static int pmp(CPURISCVState *env, int csrno)
+static RiscVException pmp(CPURISCVState *env, int csrno)
 {
-    return -!riscv_feature(env, RISCV_FEATURE_PMP);
+    if (riscv_feature(env, RISCV_FEATURE_PMP)) {
+        return RISCV_EXCP_NONE;
+    }
+
+    return RISCV_EXCP_ILLEGAL_INST;
 }
 #endif
 
@@ -1312,8 +1320,8 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
         return -RISCV_EXCP_ILLEGAL_INST;
     }
     ret = csr_ops[csrno].predicate(env, csrno);
-    if (ret < 0) {
-        return ret;
+    if (ret > 0) {
+        return -ret;
     }
 
     /* execute combined read/write operation if it exists */
-- 
2.30.1

Re: [PATCH v1 2/5] target/riscv: Use the RiscVException enum for CSR predicates

[Richard Henderson]

On 3/17/21 11:39 AM, Alistair Francis wrote:
> @@ -1312,8 +1320,8 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
>           return -RISCV_EXCP_ILLEGAL_INST;
>       }
>       ret = csr_ops[csrno].predicate(env, csrno);
> -    if (ret < 0) {
> -        return ret;
> +    if (ret > 0) {
> +        return -ret;
>       }

I think you want

   if (ret != RISCV_EXCP_NONE) {
      return -ret;
   }

here.  But of course this outer interface is still confused until patches 4+5. 
  So perhaps it doesn't matter.


r~

Re: [PATCH v1 2/5] target/riscv: Use the RiscVException enum for CSR predicates

[Alistair Francis]

On Wed, Mar 17, 2021 at 3:44 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 3/17/21 11:39 AM, Alistair Francis wrote:
> > @@ -1312,8 +1320,8 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
> >           return -RISCV_EXCP_ILLEGAL_INST;
> >       }
> >       ret = csr_ops[csrno].predicate(env, csrno);
> > -    if (ret < 0) {
> > -        return ret;
> > +    if (ret > 0) {
> > +        return -ret;
> >       }
>
> I think you want
>
>    if (ret != RISCV_EXCP_NONE) {
>       return -ret;
>    }
>
> here.  But of course this outer interface is still confused until patches 4+5.
>   So perhaps it doesn't matter.

It probably doesn't, but it reduces churn so I have fixed this.

Alistair

>
>
> r~

[PATCH v1 3/5] target/riscv: Fix 32-bit HS mode access permissions

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/csr.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index da9baff6fb..d10f47c3fb 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -181,7 +181,11 @@ static RiscVException hmode(CPURISCVState *env, int csrno)
 static RiscVException hmode32(CPURISCVState *env, int csrno)
 {
     if (!riscv_cpu_is_32bit(env)) {
-        return RISCV_EXCP_NONE;
+        if (riscv_cpu_virt_enabled(env)) {
+            return RISCV_EXCP_ILLEGAL_INST;
+        } else {
+            return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
+        }
     }
 
     return hmode(env, csrno);
-- 
2.30.1

[PATCH v1 4/5] target/riscv: Use the RiscVException enum for CSR operations

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.h |  14 +-
 target/riscv/csr.c | 658 +++++++++++++++++++++++++++------------------
 2 files changed, 398 insertions(+), 274 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 073a994d13..7af9fff776 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -471,12 +471,14 @@ static inline target_ulong riscv_csr_read(CPURISCVState *env, int csrno)
 
 typedef RiscVException (*riscv_csr_predicate_fn)(CPURISCVState *env,
                                                  int csrno);
-typedef int (*riscv_csr_read_fn)(CPURISCVState *env, int csrno,
-    target_ulong *ret_value);
-typedef int (*riscv_csr_write_fn)(CPURISCVState *env, int csrno,
-    target_ulong new_value);
-typedef int (*riscv_csr_op_fn)(CPURISCVState *env, int csrno,
-    target_ulong *ret_value, target_ulong new_value, target_ulong write_mask);
+typedef RiscVException (*riscv_csr_read_fn)(CPURISCVState *env, int csrno,
+                                            target_ulong *ret_value);
+typedef RiscVException (*riscv_csr_write_fn)(CPURISCVState *env, int csrno,
+                                             target_ulong new_value);
+typedef RiscVException (*riscv_csr_op_fn)(CPURISCVState *env, int csrno,
+                                          target_ulong *ret_value,
+                                          target_ulong new_value,
+                                          target_ulong write_mask);
 
 typedef struct {
     const char *name;
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index d10f47c3fb..61b2abdc14 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -203,57 +203,62 @@ static RiscVException pmp(CPURISCVState *env, int csrno)
 #endif
 
 /* User Floating-Point CSRs */
-static int read_fflags(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_fflags(CPURISCVState *env, int csrno,
+                                  target_ulong *val)
 {
 #if !defined(CONFIG_USER_ONLY)
     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 #endif
     *val = riscv_cpu_get_fflags(env);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_fflags(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_fflags(CPURISCVState *env, int csrno,
+                                   target_ulong val)
 {
 #if !defined(CONFIG_USER_ONLY)
     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
     env->mstatus |= MSTATUS_FS;
 #endif
     riscv_cpu_set_fflags(env, val & (FSR_AEXC >> FSR_AEXC_SHIFT));
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_frm(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_frm(CPURISCVState *env, int csrno,
+                               target_ulong *val)
 {
 #if !defined(CONFIG_USER_ONLY)
     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 #endif
     *val = env->frm;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_frm(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_frm(CPURISCVState *env, int csrno,
+                                target_ulong val)
 {
 #if !defined(CONFIG_USER_ONLY)
     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
     env->mstatus |= MSTATUS_FS;
 #endif
     env->frm = val & (FSR_RD >> FSR_RD_SHIFT);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_fcsr(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_fcsr(CPURISCVState *env, int csrno,
+                                target_ulong *val)
 {
 #if !defined(CONFIG_USER_ONLY)
     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 #endif
     *val = (riscv_cpu_get_fflags(env) << FSR_AEXC_SHIFT)
@@ -262,14 +267,15 @@ static int read_fcsr(CPURISCVState *env, int csrno, target_ulong *val)
         *val |= (env->vxrm << FSR_VXRM_SHIFT)
                 | (env->vxsat << FSR_VXSAT_SHIFT);
     }
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_fcsr(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_fcsr(CPURISCVState *env, int csrno,
+                                 target_ulong val)
 {
 #if !defined(CONFIG_USER_ONLY)
     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
     env->mstatus |= MSTATUS_FS;
 #endif
@@ -279,59 +285,68 @@ static int write_fcsr(CPURISCVState *env, int csrno, target_ulong val)
         env->vxsat = (val & FSR_VXSAT) >> FSR_VXSAT_SHIFT;
     }
     riscv_cpu_set_fflags(env, (val & FSR_AEXC) >> FSR_AEXC_SHIFT);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_vtype(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vtype(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     *val = env->vtype;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_vl(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vl(CPURISCVState *env, int csrno,
+                              target_ulong *val)
 {
     *val = env->vl;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_vxrm(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vxrm(CPURISCVState *env, int csrno,
+                                target_ulong *val)
 {
     *val = env->vxrm;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vxrm(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vxrm(CPURISCVState *env, int csrno,
+                                 target_ulong val)
 {
     env->vxrm = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_vxsat(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vxsat(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     *val = env->vxsat;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vxsat(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vxsat(CPURISCVState *env, int csrno,
+                                  target_ulong val)
 {
     env->vxsat = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_vstart(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vstart(CPURISCVState *env, int csrno,
+                                  target_ulong *val)
 {
     *val = env->vstart;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vstart(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vstart(CPURISCVState *env, int csrno,
+                                   target_ulong val)
 {
     env->vstart = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* User Timers and Counters */
-static int read_instret(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_instret(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
 #if !defined(CONFIG_USER_ONLY)
     if (icount_enabled()) {
@@ -342,10 +357,11 @@ static int read_instret(CPURISCVState *env, int csrno, target_ulong *val)
 #else
     *val = cpu_get_host_ticks();
 #endif
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_instreth(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_instreth(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
 {
 #if !defined(CONFIG_USER_ONLY)
     if (icount_enabled()) {
@@ -356,46 +372,50 @@ static int read_instreth(CPURISCVState *env, int csrno, target_ulong *val)
 #else
     *val = cpu_get_host_ticks() >> 32;
 #endif
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 #if defined(CONFIG_USER_ONLY)
-static int read_time(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_time(CPURISCVState *env, int csrno,
+                                target_ulong *val)
 {
     *val = cpu_get_host_ticks();
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_timeh(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_timeh(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     *val = cpu_get_host_ticks() >> 32;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 #else /* CONFIG_USER_ONLY */
 
-static int read_time(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_time(CPURISCVState *env, int csrno,
+                                target_ulong *val)
 {
     uint64_t delta = riscv_cpu_virt_enabled(env) ? env->htimedelta : 0;
 
     if (!env->rdtime_fn) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     *val = env->rdtime_fn(env->rdtime_fn_arg) + delta;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_timeh(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_timeh(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     uint64_t delta = riscv_cpu_virt_enabled(env) ? env->htimedelta : 0;
 
     if (!env->rdtime_fn) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     *val = (env->rdtime_fn(env->rdtime_fn_arg) + delta) >> 32;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* Machine constants */
@@ -448,22 +468,26 @@ static const char valid_vm_1_10_64[16] = {
 };
 
 /* Machine Information Registers */
-static int read_zero(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_zero(CPURISCVState *env, int csrno,
+                                target_ulong *val)
 {
-    return *val = 0;
+    *val = 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mhartid(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mhartid(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
     *val = env->mhartid;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* Machine Trap Setup */
-static int read_mstatus(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mstatus(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
     *val = env->mstatus;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 static int validate_vm(CPURISCVState *env, target_ulong vm)
@@ -475,7 +499,8 @@ static int validate_vm(CPURISCVState *env, target_ulong vm)
     }
 }
 
-static int write_mstatus(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mstatus(CPURISCVState *env, int csrno,
+                                    target_ulong val)
 {
     uint64_t mstatus = env->mstatus;
     uint64_t mask = 0;
@@ -506,16 +531,18 @@ static int write_mstatus(CPURISCVState *env, int csrno, target_ulong val)
     mstatus = set_field(mstatus, MSTATUS_SD, dirty);
     env->mstatus = mstatus;
 
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mstatush(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mstatush(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
 {
     *val = env->mstatus >> 32;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mstatush(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mstatush(CPURISCVState *env, int csrno,
+                                     target_ulong val)
 {
     uint64_t valh = (uint64_t)val << 32;
     uint64_t mask = MSTATUS_MPV | MSTATUS_GVA;
@@ -526,26 +553,28 @@ static int write_mstatush(CPURISCVState *env, int csrno, target_ulong val)
 
     env->mstatus = (env->mstatus & ~mask) | (valh & mask);
 
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_misa(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_misa(CPURISCVState *env, int csrno,
+                                target_ulong *val)
 {
     *val = env->misa;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_misa(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_misa(CPURISCVState *env, int csrno,
+                                 target_ulong val)
 {
     if (!riscv_feature(env, RISCV_FEATURE_MISA)) {
         /* drop write to misa */
-        return 0;
+        return RISCV_EXCP_NONE;
     }
 
     /* 'I' or 'E' must be present */
     if (!(val & (RVI | RVE))) {
         /* It is not, drop write to misa */
-        return 0;
+        return RISCV_EXCP_NONE;
     }
 
     /* 'E' excludes all other extensions */
@@ -553,7 +582,7 @@ static int write_misa(CPURISCVState *env, int csrno, target_ulong val)
         /* when we support 'E' we can do "val = RVE;" however
          * for now we just drop writes if 'E' is present.
          */
-        return 0;
+        return RISCV_EXCP_NONE;
     }
 
     /* Mask extensions that are not supported by this hart */
@@ -584,55 +613,63 @@ static int write_misa(CPURISCVState *env, int csrno, target_ulong val)
 
     env->misa = val;
 
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_medeleg(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_medeleg(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
     *val = env->medeleg;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_medeleg(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_medeleg(CPURISCVState *env, int csrno,
+                                    target_ulong val)
 {
     env->medeleg = (env->medeleg & ~delegable_excps) | (val & delegable_excps);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mideleg(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mideleg(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
     *val = env->mideleg;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mideleg(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mideleg(CPURISCVState *env, int csrno,
+                                    target_ulong val)
 {
     env->mideleg = (env->mideleg & ~delegable_ints) | (val & delegable_ints);
     if (riscv_has_ext(env, RVH)) {
         env->mideleg |= VS_MODE_INTERRUPTS;
     }
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mie(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mie(CPURISCVState *env, int csrno,
+                               target_ulong *val)
 {
     *val = env->mie;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mie(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mie(CPURISCVState *env, int csrno,
+                                target_ulong val)
 {
     env->mie = (env->mie & ~all_ints) | (val & all_ints);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mtvec(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mtvec(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     *val = env->mtvec;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mtvec(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mtvec(CPURISCVState *env, int csrno,
+                                  target_ulong val)
 {
     /* bits [1:0] encode mode; 0 = direct, 1 = vectored, 2 >= reserved */
     if ((val & 3) < 2) {
@@ -640,92 +677,105 @@ static int write_mtvec(CPURISCVState *env, int csrno, target_ulong val)
     } else {
         qemu_log_mask(LOG_UNIMP, "CSR_MTVEC: reserved mode not supported\n");
     }
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mcounteren(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mcounteren(CPURISCVState *env, int csrno,
+                                      target_ulong *val)
 {
     *val = env->mcounteren;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mcounteren(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mcounteren(CPURISCVState *env, int csrno,
+                                       target_ulong val)
 {
     env->mcounteren = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* This regiser is replaced with CSR_MCOUNTINHIBIT in 1.11.0 */
-static int read_mscounteren(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mscounteren(CPURISCVState *env, int csrno,
+                                       target_ulong *val)
 {
     if (env->priv_ver < PRIV_VERSION_1_11_0) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
     *val = env->mcounteren;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* This regiser is replaced with CSR_MCOUNTINHIBIT in 1.11.0 */
-static int write_mscounteren(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mscounteren(CPURISCVState *env, int csrno,
+                                        target_ulong val)
 {
     if (env->priv_ver < PRIV_VERSION_1_11_0) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
     env->mcounteren = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* Machine Trap Handling */
-static int read_mscratch(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mscratch(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
 {
     *val = env->mscratch;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mscratch(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mscratch(CPURISCVState *env, int csrno,
+                                     target_ulong val)
 {
     env->mscratch = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mepc(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mepc(CPURISCVState *env, int csrno,
+                                     target_ulong *val)
 {
     *val = env->mepc;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mepc(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mepc(CPURISCVState *env, int csrno,
+                                     target_ulong val)
 {
     env->mepc = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mcause(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mcause(CPURISCVState *env, int csrno,
+                                     target_ulong *val)
 {
     *val = env->mcause;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mcause(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mcause(CPURISCVState *env, int csrno,
+                                     target_ulong val)
 {
     env->mcause = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mbadaddr(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mbadaddr(CPURISCVState *env, int csrno,
+                                     target_ulong *val)
 {
     *val = env->mbadaddr;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mbadaddr(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mbadaddr(CPURISCVState *env, int csrno,
+                                     target_ulong val)
 {
     env->mbadaddr = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int rmw_mip(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                   target_ulong new_value, target_ulong write_mask)
+static RiscVException rmw_mip(CPURISCVState *env, int csrno,
+                              target_ulong *ret_value,
+                              target_ulong new_value, target_ulong write_mask)
 {
     RISCVCPU *cpu = env_archcpu(env);
     /* Allow software control of delegable interrupts not claimed by hardware */
@@ -742,25 +792,28 @@ static int rmw_mip(CPURISCVState *env, int csrno, target_ulong *ret_value,
         *ret_value = old_mip;
     }
 
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* Supervisor Trap Setup */
-static int read_sstatus(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_sstatus(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
     target_ulong mask = (sstatus_v1_10_mask);
     *val = env->mstatus & mask;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_sstatus(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_sstatus(CPURISCVState *env, int csrno,
+                                    target_ulong val)
 {
     target_ulong mask = (sstatus_v1_10_mask);
     target_ulong newval = (env->mstatus & ~mask) | (val & mask);
     return write_mstatus(env, CSR_MSTATUS, newval);
 }
 
-static int read_sie(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_sie(CPURISCVState *env, int csrno,
+                               target_ulong *val)
 {
     if (riscv_cpu_virt_enabled(env)) {
         /* Tell the guest the VS bits, shifted to the S bit locations */
@@ -768,10 +821,11 @@ static int read_sie(CPURISCVState *env, int csrno, target_ulong *val)
     } else {
         *val = env->mie & env->mideleg;
     }
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_sie(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_sie(CPURISCVState *env, int csrno,
+                                target_ulong val)
 {
     target_ulong newval;
 
@@ -786,13 +840,15 @@ static int write_sie(CPURISCVState *env, int csrno, target_ulong val)
     return write_mie(env, CSR_MIE, newval);
 }
 
-static int read_stvec(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_stvec(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     *val = env->stvec;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_stvec(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_stvec(CPURISCVState *env, int csrno,
+                                  target_ulong val)
 {
     /* bits [1:0] encode mode; 0 = direct, 1 = vectored, 2 >= reserved */
     if ((val & 3) < 2) {
@@ -800,72 +856,83 @@ static int write_stvec(CPURISCVState *env, int csrno, target_ulong val)
     } else {
         qemu_log_mask(LOG_UNIMP, "CSR_STVEC: reserved mode not supported\n");
     }
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_scounteren(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_scounteren(CPURISCVState *env, int csrno,
+                                      target_ulong *val)
 {
     *val = env->scounteren;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_scounteren(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_scounteren(CPURISCVState *env, int csrno,
+                                       target_ulong val)
 {
     env->scounteren = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* Supervisor Trap Handling */
-static int read_sscratch(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_sscratch(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
 {
     *val = env->sscratch;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_sscratch(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_sscratch(CPURISCVState *env, int csrno,
+                                     target_ulong val)
 {
     env->sscratch = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_sepc(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_sepc(CPURISCVState *env, int csrno,
+                                target_ulong *val)
 {
     *val = env->sepc;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_sepc(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_sepc(CPURISCVState *env, int csrno,
+                                 target_ulong val)
 {
     env->sepc = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_scause(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_scause(CPURISCVState *env, int csrno,
+                                  target_ulong *val)
 {
     *val = env->scause;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_scause(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_scause(CPURISCVState *env, int csrno,
+                                   target_ulong val)
 {
     env->scause = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_sbadaddr(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_sbadaddr(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
 {
     *val = env->sbadaddr;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_sbadaddr(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_sbadaddr(CPURISCVState *env, int csrno,
+                                     target_ulong val)
 {
     env->sbadaddr = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int rmw_sip(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                   target_ulong new_value, target_ulong write_mask)
+static RiscVException rmw_sip(CPURISCVState *env, int csrno,
+                              target_ulong *ret_value,
+                              target_ulong new_value, target_ulong write_mask)
 {
     int ret;
 
@@ -873,8 +940,8 @@ static int rmw_sip(CPURISCVState *env, int csrno, target_ulong *ret_value,
         /* Shift the new values to line up with the VS bits */
         ret = rmw_mip(env, CSR_MSTATUS, ret_value, new_value << 1,
                       (write_mask & sip_writable_mask) << 1 & env->mideleg);
-        ret &= vsip_writable_mask;
-        ret >>= 1;
+        *ret_value &= vsip_writable_mask;
+        *ret_value >>= 1;
     } else {
         ret = rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
                       write_mask & env->mideleg & sip_writable_mask);
@@ -885,32 +952,34 @@ static int rmw_sip(CPURISCVState *env, int csrno, target_ulong *ret_value,
 }
 
 /* Supervisor Protection and Translation */
-static int read_satp(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_satp(CPURISCVState *env, int csrno,
+                                target_ulong *val)
 {
     if (!riscv_feature(env, RISCV_FEATURE_MMU)) {
         *val = 0;
-        return 0;
+        return RISCV_EXCP_NONE;
     }
 
     if (env->priv == PRV_S && get_field(env->mstatus, MSTATUS_TVM)) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     } else {
         *val = env->satp;
     }
 
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_satp(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_satp(CPURISCVState *env, int csrno,
+                                 target_ulong val)
 {
     if (!riscv_feature(env, RISCV_FEATURE_MMU)) {
-        return 0;
+        return RISCV_EXCP_NONE;
     }
     if (validate_vm(env, get_field(val, SATP_MODE)) &&
         ((val ^ env->satp) & (SATP_MODE | SATP_ASID | SATP_PPN)))
     {
         if (env->priv == PRV_S && get_field(env->mstatus, MSTATUS_TVM)) {
-            return -RISCV_EXCP_ILLEGAL_INST;
+            return RISCV_EXCP_ILLEGAL_INST;
         } else {
             if ((val ^ env->satp) & SATP_ASID) {
                 tlb_flush(env_cpu(env));
@@ -918,11 +987,12 @@ static int write_satp(CPURISCVState *env, int csrno, target_ulong val)
             env->satp = val;
         }
     }
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* Hypervisor Extensions */
-static int read_hstatus(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_hstatus(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
     *val = env->hstatus;
     if (!riscv_cpu_is_32bit(env)) {
@@ -931,10 +1001,11 @@ static int read_hstatus(CPURISCVState *env, int csrno, target_ulong *val)
     }
     /* We only support little endian */
     *val = set_field(*val, HSTATUS_VSBE, 0);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_hstatus(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_hstatus(CPURISCVState *env, int csrno,
+                                    target_ulong val)
 {
     env->hstatus = val;
     if (!riscv_cpu_is_32bit(env) && get_field(val, HSTATUS_VSXL) != 2) {
@@ -943,35 +1014,40 @@ static int write_hstatus(CPURISCVState *env, int csrno, target_ulong val)
     if (get_field(val, HSTATUS_VSBE) != 0) {
         qemu_log_mask(LOG_UNIMP, "QEMU does not support big endian guests.");
     }
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_hedeleg(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_hedeleg(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
     *val = env->hedeleg;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_hedeleg(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_hedeleg(CPURISCVState *env, int csrno,
+                                    target_ulong val)
 {
     env->hedeleg = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_hideleg(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_hideleg(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
     *val = env->hideleg;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_hideleg(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_hideleg(CPURISCVState *env, int csrno,
+                                    target_ulong val)
 {
     env->hideleg = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int rmw_hvip(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                   target_ulong new_value, target_ulong write_mask)
+static RiscVException rmw_hvip(CPURISCVState *env, int csrno,
+                               target_ulong *ret_value,
+                               target_ulong new_value, target_ulong write_mask)
 {
     int ret = rmw_mip(env, 0, ret_value, new_value,
                       write_mask & hip_writable_mask);
@@ -981,8 +1057,9 @@ static int rmw_hvip(CPURISCVState *env, int csrno, target_ulong *ret_value,
     return ret;
 }
 
-static int rmw_hip(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                   target_ulong new_value, target_ulong write_mask)
+static RiscVException rmw_hip(CPURISCVState *env, int csrno,
+                              target_ulong *ret_value,
+                              target_ulong new_value, target_ulong write_mask)
 {
     int ret = rmw_mip(env, 0, ret_value, new_value,
                       write_mask & hip_writable_mask);
@@ -992,103 +1069,119 @@ static int rmw_hip(CPURISCVState *env, int csrno, target_ulong *ret_value,
     return ret;
 }
 
-static int read_hie(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_hie(CPURISCVState *env, int csrno,
+                               target_ulong *val)
 {
     *val = env->mie & VS_MODE_INTERRUPTS;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_hie(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_hie(CPURISCVState *env, int csrno,
+                                target_ulong val)
 {
     target_ulong newval = (env->mie & ~VS_MODE_INTERRUPTS) | (val & VS_MODE_INTERRUPTS);
     return write_mie(env, CSR_MIE, newval);
 }
 
-static int read_hcounteren(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_hcounteren(CPURISCVState *env, int csrno,
+                                      target_ulong *val)
 {
     *val = env->hcounteren;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_hcounteren(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_hcounteren(CPURISCVState *env, int csrno,
+                                       target_ulong val)
 {
     env->hcounteren = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_hgeie(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_hgeie(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     qemu_log_mask(LOG_UNIMP, "No support for a non-zero GEILEN.");
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_hgeie(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_hgeie(CPURISCVState *env, int csrno,
+                                  target_ulong val)
 {
     qemu_log_mask(LOG_UNIMP, "No support for a non-zero GEILEN.");
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_htval(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_htval(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     *val = env->htval;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_htval(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_htval(CPURISCVState *env, int csrno,
+                                  target_ulong val)
 {
     env->htval = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_htinst(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_htinst(CPURISCVState *env, int csrno,
+                                  target_ulong *val)
 {
     *val = env->htinst;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_htinst(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_htinst(CPURISCVState *env, int csrno,
+                                   target_ulong val)
 {
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_hgeip(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_hgeip(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     qemu_log_mask(LOG_UNIMP, "No support for a non-zero GEILEN.");
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_hgeip(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_hgeip(CPURISCVState *env, int csrno,
+                                  target_ulong val)
 {
     qemu_log_mask(LOG_UNIMP, "No support for a non-zero GEILEN.");
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_hgatp(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_hgatp(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     *val = env->hgatp;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_hgatp(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_hgatp(CPURISCVState *env, int csrno,
+                                  target_ulong val)
 {
     env->hgatp = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_htimedelta(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_htimedelta(CPURISCVState *env, int csrno,
+                                      target_ulong *val)
 {
     if (!env->rdtime_fn) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     *val = env->htimedelta;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_htimedelta(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_htimedelta(CPURISCVState *env, int csrno,
+                                       target_ulong val)
 {
     if (!env->rdtime_fn) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     if (riscv_cpu_is_32bit(env)) {
@@ -1096,182 +1189,208 @@ static int write_htimedelta(CPURISCVState *env, int csrno, target_ulong val)
     } else {
         env->htimedelta = val;
     }
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_htimedeltah(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_htimedeltah(CPURISCVState *env, int csrno,
+                                       target_ulong *val)
 {
     if (!env->rdtime_fn) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     *val = env->htimedelta >> 32;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_htimedeltah(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_htimedeltah(CPURISCVState *env, int csrno,
+                                        target_ulong val)
 {
     if (!env->rdtime_fn) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     env->htimedelta = deposit64(env->htimedelta, 32, 32, (uint64_t)val);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* Virtual CSR Registers */
-static int read_vsstatus(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vsstatus(CPURISCVState *env, int csrno,
+                                    target_ulong *val)
 {
     *val = env->vsstatus;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vsstatus(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vsstatus(CPURISCVState *env, int csrno,
+                                     target_ulong val)
 {
     uint64_t mask = (target_ulong)-1;
     env->vsstatus = (env->vsstatus & ~mask) | (uint64_t)val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int rmw_vsip(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                    target_ulong new_value, target_ulong write_mask)
+static RiscVException rmw_vsip(CPURISCVState *env, int csrno,
+                               target_ulong *ret_value,
+                               target_ulong new_value, target_ulong write_mask)
 {
-    int ret = rmw_mip(env, 0, ret_value, new_value,
-                      write_mask & env->mideleg & vsip_writable_mask);
-    return ret;
+    return rmw_mip(env, 0, ret_value, new_value,
+                   write_mask & env->mideleg & vsip_writable_mask);
 }
 
-static int read_vsie(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vsie(CPURISCVState *env, int csrno,
+                                target_ulong *val)
 {
     *val = env->mie & env->mideleg & VS_MODE_INTERRUPTS;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vsie(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vsie(CPURISCVState *env, int csrno,
+                                 target_ulong val)
 {
     target_ulong newval = (env->mie & ~env->mideleg) | (val & env->mideleg & MIP_VSSIP);
     return write_mie(env, CSR_MIE, newval);
 }
 
-static int read_vstvec(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vstvec(CPURISCVState *env, int csrno,
+                                  target_ulong *val)
 {
     *val = env->vstvec;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vstvec(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vstvec(CPURISCVState *env, int csrno,
+                                   target_ulong val)
 {
     env->vstvec = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_vsscratch(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vsscratch(CPURISCVState *env, int csrno,
+                                     target_ulong *val)
 {
     *val = env->vsscratch;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vsscratch(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vsscratch(CPURISCVState *env, int csrno,
+                                      target_ulong val)
 {
     env->vsscratch = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_vsepc(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vsepc(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     *val = env->vsepc;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vsepc(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vsepc(CPURISCVState *env, int csrno,
+                                  target_ulong val)
 {
     env->vsepc = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_vscause(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vscause(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
     *val = env->vscause;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vscause(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vscause(CPURISCVState *env, int csrno,
+                                    target_ulong val)
 {
     env->vscause = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_vstval(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vstval(CPURISCVState *env, int csrno,
+                                  target_ulong *val)
 {
     *val = env->vstval;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vstval(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vstval(CPURISCVState *env, int csrno,
+                                   target_ulong val)
 {
     env->vstval = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_vsatp(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_vsatp(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
 {
     *val = env->vsatp;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_vsatp(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_vsatp(CPURISCVState *env, int csrno,
+                                  target_ulong val)
 {
     env->vsatp = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mtval2(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mtval2(CPURISCVState *env, int csrno,
+                                  target_ulong *val)
 {
     *val = env->mtval2;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mtval2(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mtval2(CPURISCVState *env, int csrno,
+                                   target_ulong val)
 {
     env->mtval2 = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_mtinst(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_mtinst(CPURISCVState *env, int csrno,
+                                  target_ulong *val)
 {
     *val = env->mtinst;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_mtinst(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_mtinst(CPURISCVState *env, int csrno,
+                                   target_ulong val)
 {
     env->mtinst = val;
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /* Physical Memory Protection */
-static int read_pmpcfg(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_pmpcfg(CPURISCVState *env, int csrno,
+                                  target_ulong *val)
 {
     *val = pmpcfg_csr_read(env, csrno - CSR_PMPCFG0);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_pmpcfg(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_pmpcfg(CPURISCVState *env, int csrno,
+                                   target_ulong val)
 {
     pmpcfg_csr_write(env, csrno - CSR_PMPCFG0, val);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int read_pmpaddr(CPURISCVState *env, int csrno, target_ulong *val)
+static RiscVException read_pmpaddr(CPURISCVState *env, int csrno,
+                                   target_ulong *val)
 {
     *val = pmpaddr_csr_read(env, csrno - CSR_PMPADDR0);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
-static int write_pmpaddr(CPURISCVState *env, int csrno, target_ulong val)
+static RiscVException write_pmpaddr(CPURISCVState *env, int csrno,
+                                    target_ulong val)
 {
     pmpaddr_csr_write(env, csrno - CSR_PMPADDR0, val);
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 #endif
@@ -1324,24 +1443,27 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
         return -RISCV_EXCP_ILLEGAL_INST;
     }
     ret = csr_ops[csrno].predicate(env, csrno);
-    if (ret > 0) {
+    if (ret != RISCV_EXCP_NONE) {
         return -ret;
     }
 
     /* execute combined read/write operation if it exists */
     if (csr_ops[csrno].op) {
-        return csr_ops[csrno].op(env, csrno, ret_value, new_value, write_mask);
+        ret = csr_ops[csrno].op(env, csrno, ret_value, new_value, write_mask);
+        if (ret != RISCV_EXCP_NONE) {
+            return -ret;
+        }
+        return 0;
     }
 
     /* if no accessor exists then return failure */
     if (!csr_ops[csrno].read) {
         return -RISCV_EXCP_ILLEGAL_INST;
     }
-
     /* read old value */
     ret = csr_ops[csrno].read(env, csrno, &old_value);
-    if (ret < 0) {
-        return ret;
+    if (ret != RISCV_EXCP_NONE) {
+        return -ret;
     }
 
     /* write value if writable and write mask set, otherwise drop writes */
@@ -1349,8 +1471,8 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
         new_value = (old_value & ~write_mask) | (new_value & write_mask);
         if (csr_ops[csrno].write) {
             ret = csr_ops[csrno].write(env, csrno, new_value);
-            if (ret < 0) {
-                return ret;
+            if (ret != RISCV_EXCP_NONE) {
+                return -ret;
             }
         }
     }
-- 
2.30.1

[PATCH v1 5/5] target/riscv: Use RiscVException enum for CSR access

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.h       | 11 +++++++----
 target/riscv/csr.c       | 37 ++++++++++++++++++-------------------
 target/riscv/gdbstub.c   |  8 ++++----
 target/riscv/op_helper.c | 18 +++++++++---------
 4 files changed, 38 insertions(+), 36 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 7af9fff776..179685d07b 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -451,10 +451,13 @@ static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
     *pflags = flags;
 }
 
-int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                target_ulong new_value, target_ulong write_mask);
-int riscv_csrrw_debug(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                      target_ulong new_value, target_ulong write_mask);
+RiscVException riscv_csrrw(CPURISCVState *env, int csrno,
+                           target_ulong *ret_value,
+                           target_ulong new_value, target_ulong write_mask);
+RiscVException riscv_csrrw_debug(CPURISCVState *env, int csrno,
+                                 target_ulong *ret_value,
+                                 target_ulong new_value,
+                                 target_ulong write_mask);
 
 static inline void riscv_csr_write(CPURISCVState *env, int csrno,
                                    target_ulong val)
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 61b2abdc14..fbe38dd261 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1404,10 +1404,11 @@ static RiscVException write_pmpaddr(CPURISCVState *env, int csrno,
  * csrrc  <->  riscv_csrrw(env, csrno, ret_value, 0, value);
  */
 
-int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                target_ulong new_value, target_ulong write_mask)
+RiscVException riscv_csrrw(CPURISCVState *env, int csrno,
+                           target_ulong *ret_value,
+                           target_ulong new_value, target_ulong write_mask)
 {
-    int ret;
+    RiscVException ret;
     target_ulong old_value;
     RISCVCPU *cpu = env_archcpu(env);
 
@@ -1429,41 +1430,37 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
 
     if ((write_mask && read_only) ||
         (!env->debugger && (effective_priv < get_field(csrno, 0x300)))) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 #endif
 
     /* ensure the CSR extension is enabled. */
     if (!cpu->cfg.ext_icsr) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     /* check predicate */
     if (!csr_ops[csrno].predicate) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
     ret = csr_ops[csrno].predicate(env, csrno);
     if (ret != RISCV_EXCP_NONE) {
-        return -ret;
+        return ret;
     }
 
     /* execute combined read/write operation if it exists */
     if (csr_ops[csrno].op) {
-        ret = csr_ops[csrno].op(env, csrno, ret_value, new_value, write_mask);
-        if (ret != RISCV_EXCP_NONE) {
-            return -ret;
-        }
-        return 0;
+        return csr_ops[csrno].op(env, csrno, ret_value, new_value, write_mask);
     }
 
     /* if no accessor exists then return failure */
     if (!csr_ops[csrno].read) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
     /* read old value */
     ret = csr_ops[csrno].read(env, csrno, &old_value);
     if (ret != RISCV_EXCP_NONE) {
-        return -ret;
+        return ret;
     }
 
     /* write value if writable and write mask set, otherwise drop writes */
@@ -1472,7 +1469,7 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
         if (csr_ops[csrno].write) {
             ret = csr_ops[csrno].write(env, csrno, new_value);
             if (ret != RISCV_EXCP_NONE) {
-                return -ret;
+                return ret;
             }
         }
     }
@@ -1482,17 +1479,19 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
         *ret_value = old_value;
     }
 
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /*
  * Debugger support.  If not in user mode, set env->debugger before the
  * riscv_csrrw call and clear it after the call.
  */
-int riscv_csrrw_debug(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                target_ulong new_value, target_ulong write_mask)
+RiscVException riscv_csrrw_debug(CPURISCVState *env, int csrno,
+                                 target_ulong *ret_value,
+                                 target_ulong new_value,
+                                 target_ulong write_mask)
 {
-    int ret;
+    RiscVException ret;
 #if !defined(CONFIG_USER_ONLY)
     env->debugger = true;
 #endif
diff --git a/target/riscv/gdbstub.c b/target/riscv/gdbstub.c
index 5f96b7ea2a..fdc51ea165 100644
--- a/target/riscv/gdbstub.c
+++ b/target/riscv/gdbstub.c
@@ -71,7 +71,7 @@ static int riscv_gdb_get_fpu(CPURISCVState *env, GByteArray *buf, int n)
          */
         result = riscv_csrrw_debug(env, n - 32, &val,
                                    0, 0);
-        if (result == 0) {
+        if (result != RISCV_EXCP_NONE) {
             return gdb_get_regl(buf, val);
         }
     }
@@ -94,7 +94,7 @@ static int riscv_gdb_set_fpu(CPURISCVState *env, uint8_t *mem_buf, int n)
          */
         result = riscv_csrrw_debug(env, n - 32, NULL,
                                    val, -1);
-        if (result == 0) {
+        if (result != RISCV_EXCP_NONE) {
             return sizeof(target_ulong);
         }
     }
@@ -108,7 +108,7 @@ static int riscv_gdb_get_csr(CPURISCVState *env, GByteArray *buf, int n)
         int result;
 
         result = riscv_csrrw_debug(env, n, &val, 0, 0);
-        if (result == 0) {
+        if (result != RISCV_EXCP_NONE) {
             return gdb_get_regl(buf, val);
         }
     }
@@ -122,7 +122,7 @@ static int riscv_gdb_set_csr(CPURISCVState *env, uint8_t *mem_buf, int n)
         int result;
 
         result = riscv_csrrw_debug(env, n, NULL, val, -1);
-        if (result == 0) {
+        if (result != RISCV_EXCP_NONE) {
             return sizeof(target_ulong);
         }
     }
diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index 1eddcb94de..c84b9f8557 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -42,10 +42,10 @@ target_ulong helper_csrrw(CPURISCVState *env, target_ulong src,
         target_ulong csr)
 {
     target_ulong val = 0;
-    int ret = riscv_csrrw(env, csr, &val, src, -1);
+    RiscVException ret = riscv_csrrw(env, csr, &val, src, -1);
 
-    if (ret < 0) {
-        riscv_raise_exception(env, -ret, GETPC());
+    if (ret != RISCV_EXCP_NONE) {
+        riscv_raise_exception(env, ret, GETPC());
     }
     return val;
 }
@@ -54,10 +54,10 @@ target_ulong helper_csrrs(CPURISCVState *env, target_ulong src,
         target_ulong csr, target_ulong rs1_pass)
 {
     target_ulong val = 0;
-    int ret = riscv_csrrw(env, csr, &val, -1, rs1_pass ? src : 0);
+    RiscVException ret = riscv_csrrw(env, csr, &val, -1, rs1_pass ? src : 0);
 
-    if (ret < 0) {
-        riscv_raise_exception(env, -ret, GETPC());
+    if (ret != RISCV_EXCP_NONE) {
+        riscv_raise_exception(env, ret, GETPC());
     }
     return val;
 }
@@ -66,10 +66,10 @@ target_ulong helper_csrrc(CPURISCVState *env, target_ulong src,
         target_ulong csr, target_ulong rs1_pass)
 {
     target_ulong val = 0;
-    int ret = riscv_csrrw(env, csr, &val, 0, rs1_pass ? src : 0);
+    RiscVException ret = riscv_csrrw(env, csr, &val, 0, rs1_pass ? src : 0);
 
-    if (ret < 0) {
-        riscv_raise_exception(env, -ret, GETPC());
+    if (ret != RISCV_EXCP_NONE) {
+        riscv_raise_exception(env, ret, GETPC());
     }
     return val;
 }
-- 
2.30.1

Re: [PATCH v1 5/5] target/riscv: Use RiscVException enum for CSR access

[Richard Henderson]

On 3/17/21 11:40 AM, Alistair Francis wrote:
>           result = riscv_csrrw_debug(env, n - 32, &val,
>                                      0, 0);
> -        if (result == 0) {
> +        if (result != RISCV_EXCP_NONE) {

This was intending == NONE.  I.e. no exception raised, let gdb proceed.


r~

Re: [PATCH v1 5/5] target/riscv: Use RiscVException enum for CSR access

[Alistair Francis]

On Thu, Mar 18, 2021 at 9:25 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 3/17/21 11:40 AM, Alistair Francis wrote:
> >           result = riscv_csrrw_debug(env, n - 32, &val,
> >                                      0, 0);
> > -        if (result == 0) {
> > +        if (result != RISCV_EXCP_NONE) {
>
> This was intending == NONE.  I.e. no exception raised, let gdb proceed.

Good catch! Fixed.

Alistair

>
>
> r~