[PATCH v5 2/4] target/riscv/pmp.c: Fix the index offset on RV64

Zong Li posted 4 patches 5 years, 3 months ago
Maintainers: Sagar Karandikar <sagark@eecs.berkeley.edu>, Palmer Dabbelt <palmer@dabbelt.com>, Bastian Koppelmann <kbastian@mail.uni-paderborn.de>, Alistair Francis <Alistair.Francis@wdc.com>
There is a newer version of this series
[PATCH v5 2/4] target/riscv/pmp.c: Fix the index offset on RV64
Posted by Zong Li 5 years, 3 months ago
On RV64, the reg_index is 2 (pmpcfg2 CSR) after the seventh pmp
entry, it is not 1 (pmpcfg1 CSR) like RV32. In the original
implementation, the second parameter of pmp_write_cfg is
"reg_index * sizeof(target_ulong)", and we get the the result
which is started from 16 if reg_index is 2, but we expect that
it should be started from 8. Separate the implementation for
RV32 and RV64 respectively.

Signed-off-by: Zong Li <zong.li@sifive.com>
---
 target/riscv/pmp.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
index 2a2b9f5363..aeba796484 100644
--- a/target/riscv/pmp.c
+++ b/target/riscv/pmp.c
@@ -318,6 +318,10 @@ void pmpcfg_csr_write(CPURISCVState *env, uint32_t reg_index,
         return;
     }
 
+#if defined(TARGET_RISCV64)
+    reg_index >>= 1;
+#endif
+
     for (i = 0; i < sizeof(target_ulong); i++) {
         cfg_val = (val >> 8 * i)  & 0xff;
         pmp_write_cfg(env, (reg_index * sizeof(target_ulong)) + i,
@@ -335,11 +339,16 @@ target_ulong pmpcfg_csr_read(CPURISCVState *env, uint32_t reg_index)
     target_ulong cfg_val = 0;
     target_ulong val = 0;
 
+    trace_pmpcfg_csr_read(env->mhartid, reg_index, cfg_val);
+
+#if defined(TARGET_RISCV64)
+    reg_index >>= 1;
+#endif
+
     for (i = 0; i < sizeof(target_ulong); i++) {
         val = pmp_read_cfg(env, (reg_index * sizeof(target_ulong)) + i);
         cfg_val |= (val << (i * 8));
     }
-    trace_pmpcfg_csr_read(env->mhartid, reg_index, cfg_val);
 
     return cfg_val;
 }
-- 
2.27.0


Re: [PATCH v5 2/4] target/riscv/pmp.c: Fix the index offset on RV64
Posted by Bin Meng 5 years, 3 months ago
On Sat, Jul 25, 2020 at 11:03 PM Zong Li <zong.li@sifive.com> wrote:
>
> On RV64, the reg_index is 2 (pmpcfg2 CSR) after the seventh pmp
> entry, it is not 1 (pmpcfg1 CSR) like RV32. In the original
> implementation, the second parameter of pmp_write_cfg is
> "reg_index * sizeof(target_ulong)", and we get the the result
> which is started from 16 if reg_index is 2, but we expect that
> it should be started from 8. Separate the implementation for
> RV32 and RV64 respectively.
>
> Signed-off-by: Zong Li <zong.li@sifive.com>
> ---
>  target/riscv/pmp.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>

Reviewed-by: Bin Meng <bin.meng@windriver.com>

Re: [PATCH v5 2/4] target/riscv/pmp.c: Fix the index offset on RV64
Posted by Alistair Francis 5 years, 3 months ago
On Sat, Jul 25, 2020 at 8:04 AM Zong Li <zong.li@sifive.com> wrote:
>
> On RV64, the reg_index is 2 (pmpcfg2 CSR) after the seventh pmp
> entry, it is not 1 (pmpcfg1 CSR) like RV32. In the original
> implementation, the second parameter of pmp_write_cfg is
> "reg_index * sizeof(target_ulong)", and we get the the result
> which is started from 16 if reg_index is 2, but we expect that
> it should be started from 8. Separate the implementation for
> RV32 and RV64 respectively.
>
> Signed-off-by: Zong Li <zong.li@sifive.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  target/riscv/pmp.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
> index 2a2b9f5363..aeba796484 100644
> --- a/target/riscv/pmp.c
> +++ b/target/riscv/pmp.c
> @@ -318,6 +318,10 @@ void pmpcfg_csr_write(CPURISCVState *env, uint32_t reg_index,
>          return;
>      }
>
> +#if defined(TARGET_RISCV64)
> +    reg_index >>= 1;
> +#endif
> +
>      for (i = 0; i < sizeof(target_ulong); i++) {
>          cfg_val = (val >> 8 * i)  & 0xff;
>          pmp_write_cfg(env, (reg_index * sizeof(target_ulong)) + i,
> @@ -335,11 +339,16 @@ target_ulong pmpcfg_csr_read(CPURISCVState *env, uint32_t reg_index)
>      target_ulong cfg_val = 0;
>      target_ulong val = 0;
>
> +    trace_pmpcfg_csr_read(env->mhartid, reg_index, cfg_val);
> +
> +#if defined(TARGET_RISCV64)
> +    reg_index >>= 1;
> +#endif
> +
>      for (i = 0; i < sizeof(target_ulong); i++) {
>          val = pmp_read_cfg(env, (reg_index * sizeof(target_ulong)) + i);
>          cfg_val |= (val << (i * 8));
>      }
> -    trace_pmpcfg_csr_read(env->mhartid, reg_index, cfg_val);
>
>      return cfg_val;
>  }
> --
> 2.27.0
>
>