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Re: [RFC v1 6/8] target/riscv: Add functions to calculate current N mask
From: |
Alistair Francis |
Subject: |
Re: [RFC v1 6/8] target/riscv: Add functions to calculate current N masked bits for pointer masking |
Date: |
Mon, 18 Sep 2023 11:46:31 +1000 |
On Sat, Sep 9, 2023 at 5:37 AM Alexey Baturo <baturo.alexey@gmail.com> wrote:
>
> Signed-off-by: Alexey Baturo <baturo.alexey@gmail.com>
> ---
> target/riscv/cpu.h | 6 ++--
> target/riscv/cpu_helper.c | 58 +++++++++++++++++++++++++++++++++++++++
> 2 files changed, 62 insertions(+), 2 deletions(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 17d0088cb4..c87c4f26a2 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -91,11 +91,9 @@ typedef enum {
> /* Enum holds maximum for N bits to be ignored depending on privilege level
> */
> typedef enum {
> PM_BARE_N_BITS = 16,
> - PM_SV32_N_BITS = 0,
> PM_SV39_N_BITS = 25,
> PM_SV48_N_BITS = 16,
> PM_SV57_N_BITS = 7,
> - PM_SV64_N_BITS = 0,
> } RISCVZjpmMaxNBits;
Didn't you just add this? Why remove parts from it
Alistair
>
> #define MMU_USER_IDX 3
> @@ -633,6 +631,10 @@ static inline uint32_t vext_get_vlmax(RISCVCPU *cpu,
> target_ulong vtype)
> void cpu_get_tb_cpu_state(CPURISCVState *env, vaddr *pc,
> uint64_t *cs_base, uint32_t *pflags);
>
> +void riscv_cpu_update_mask(CPURISCVState *env);
> +RISCVZjpmMaxNBits riscv_cpu_pm_get_n_bits(int satp_mode, int priv_mode);
> +bool riscv_cpu_pm_check_applicable(CPURISCVState *env, int priv_mode);
> +
> RISCVException riscv_csrrw(CPURISCVState *env, int csrno,
> target_ulong *ret_value,
> target_ulong new_value, target_ulong write_mask);
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index b3871b0a28..6e68b2fc27 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -144,6 +144,64 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, vaddr *pc,
> *pflags = flags;
> }
>
> +/*
> + * Curernt Zjpm v0.6.1 spec doesn't strictly specify the exact value of N
> bits.
> + * It allows it to be dependent on both translation mode and priv level.
> + * For now let's ignore priv mode and always return max available value.
> + */
> +RISCVZjpmMaxNBits riscv_cpu_pm_get_n_bits(int satp_mode, int priv_mode)
> +{
> + switch (satp_mode) {
> + case VM_1_10_MBARE:
> + return PM_BARE_N_BITS;
> + case VM_1_10_SV39:
> + return PM_SV39_N_BITS;
> + case VM_1_10_SV48:
> + return PM_SV48_N_BITS;
> + case VM_1_10_SV57:
> + return PM_SV57_N_BITS;
> + default:
> + g_assert_not_reached();
> + }
> +}
> +
> +/* For current priv level check if pointer masking should be applied */
> +bool riscv_cpu_pm_check_applicable(CPURISCVState *env, int priv_mode)
> +{
> + /* checks if appropriate extension is present and enable bit is set */
> + switch (priv_mode) {
> + case PRV_M:
> + return riscv_cpu_cfg(env)->ext_smmjpm && env->mseccfg &
> MSECCFG_MPMEN;
> + case PRV_S:
> + return riscv_cpu_cfg(env)->ext_smnjpm && env->menvcfg &
> MENVCFG_SPMEN;
> + case PRV_U:
> + return riscv_cpu_cfg(env)->ext_ssnjpm && env->senvcfg &
> SENVCFG_UPMEN;
> + default:
> + g_assert_not_reached();
> + }
> + g_assert_not_reached();
> + return false;
> +}
> +
> +void riscv_cpu_update_mask(CPURISCVState *env)
> +{
> +#ifndef CONFIG_USER_ONLY
> + int priv_mode = cpu_address_mode(env);
> + int satp_mode = 0;
> + if (riscv_cpu_mxl(env) == MXL_RV32) {
> + satp_mode = get_field(env->satp, SATP32_MODE);
> + } else {
> + satp_mode = get_field(env->satp, SATP64_MODE);
> + }
> + RISCVZjpmMaxNBits n_bits = riscv_cpu_pm_get_n_bits(satp_mode, priv_mode);
> + /* in bare mode address is not sign extended */
> + env->pm_signext = (satp_mode != VM_1_10_MBARE);
> + /* if pointer masking is applicable set env variable */
> + bool applicable = riscv_cpu_pm_check_applicable(env, priv_mode);
> + env->pm_n_bits = applicable ? n_bits : 0;
> +#endif
> +}
> +
> #ifndef CONFIG_USER_ONLY
>
> /*
> --
> 2.34.1
>
>
- [RFC v1 0/8] RISC-V Pointer Masking update to Zjpm v0.6.1, Alexey Baturo, 2023/09/08
- [RFC v1 1/8] target/riscv: Remove obsolete pointer masking extension code, Alexey Baturo, 2023/09/08
- [RFC v1 2/8] target/riscv: Add new S{sn, mn, m}jpm extensions as part of Zjpm v0.6.1, Alexey Baturo, 2023/09/08
- [RFC v1 3/8] target/riscv: Add new bits in CSRs for Zjpm 0.6.1, Alexey Baturo, 2023/09/08
- [RFC v1 4/8] Add enum with maximum ignored bits depending on privilege level for Zjpm v0.6.1, Alexey Baturo, 2023/09/08
- [RFC v1 5/8] target/riscv: Add pointer masking tb flags, Alexey Baturo, 2023/09/08
- [RFC v1 6/8] target/riscv: Add functions to calculate current N masked bits for pointer masking, Alexey Baturo, 2023/09/08
- Re: [RFC v1 6/8] target/riscv: Add functions to calculate current N masked bits for pointer masking,
Alistair Francis <=
- [RFC v1 8/8] target/riscv: enable updates for pointer masking variables and thus enable pointer masking extension, Alexey Baturo, 2023/09/08
- [RFC v1 7/8] target/riscv: Update address modify functions to take into account pointer masking, Alexey Baturo, 2023/09/08