On Wed, Jul 24, 2024 at 9:32 AM Atish Patra <ati...@rivosinc.com> wrote:
>
> From: Kaiwen Xue <kaiw...@rivosinc.com>
>
> Since xiselect and xireg also will be of use in sxcsrind, AIA should
> have its own separated interface when those CSRs are accessed.
>
> Signed-off-by: Atish Patra <ati...@rivosinc.com>
> Signed-off-by: Kaiwen Xue <kaiw...@rivosinc.com>
Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Alistair
> ---
> target/riscv/csr.c | 165
> ++++++++++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 139 insertions(+), 26 deletions(-)
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index ea3560342c4f..58be8bc3cc8c 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -29,6 +29,7 @@
> #include "sysemu/cpu-timers.h"
> #include "qemu/guest-random.h"
> #include "qapi/error.h"
> +#include <stdbool.h>
>
> /* CSR function table public API */
> void riscv_get_csr_ops(int csrno, riscv_csr_operations *ops)
> @@ -286,6 +287,15 @@ static RISCVException aia_any32(CPURISCVState *env, int
> csrno)
> return any32(env, csrno);
> }
>
> +static RISCVException csrind_or_aia_any(CPURISCVState *env, int csrno)
> +{
> + if (!riscv_cpu_cfg(env)->ext_smaia && !riscv_cpu_cfg(env)->ext_smcsrind)
> {
> + return RISCV_EXCP_ILLEGAL_INST;
> + }
> +
> + return any(env, csrno);
> +}
> +
> static RISCVException smode(CPURISCVState *env, int csrno)
> {
> if (riscv_has_ext(env, RVS)) {
> @@ -322,6 +332,30 @@ static RISCVException aia_smode32(CPURISCVState *env,
> int csrno)
> return smode32(env, csrno);
> }
>
> +static bool csrind_extensions_present(CPURISCVState *env)
> +{
> + return riscv_cpu_cfg(env)->ext_smcsrind ||
> riscv_cpu_cfg(env)->ext_sscsrind;
> +}
> +
> +static bool aia_extensions_present(CPURISCVState *env)
> +{
> + return riscv_cpu_cfg(env)->ext_smaia || riscv_cpu_cfg(env)->ext_ssaia;
> +}
> +
> +static bool csrind_or_aia_extensions_present(CPURISCVState *env)
> +{
> + return csrind_extensions_present(env) || aia_extensions_present(env);
> +}
> +
> +static RISCVException csrind_or_aia_smode(CPURISCVState *env, int csrno)
> +{
> + if (!csrind_or_aia_extensions_present(env)) {
> + return RISCV_EXCP_ILLEGAL_INST;
> + }
> +
> + return smode(env, csrno);
> +}
> +
> static RISCVException hmode(CPURISCVState *env, int csrno)
> {
> if (riscv_has_ext(env, RVH)) {
> @@ -341,6 +375,15 @@ static RISCVException hmode32(CPURISCVState *env, int
> csrno)
>
> }
>
> +static RISCVException csrind_or_aia_hmode(CPURISCVState *env, int csrno)
> +{
> + if (!csrind_or_aia_extensions_present(env)) {
> + return RISCV_EXCP_ILLEGAL_INST;
> + }
> +
> + return hmode(env, csrno);
> +}
> +
> static RISCVException umode(CPURISCVState *env, int csrno)
> {
> if (riscv_has_ext(env, RVU)) {
> @@ -1928,6 +1971,22 @@ static int aia_xlate_vs_csrno(CPURISCVState *env, int
> csrno)
> };
> }
>
> +static int csrind_xlate_vs_csrno(CPURISCVState *env, int csrno)
> +{
> + if (!env->virt_enabled) {
> + return csrno;
> + }
> +
> + switch (csrno) {
> + case CSR_SISELECT:
> + return CSR_VSISELECT;
> + case CSR_SIREG:
> + return CSR_VSIREG;
> + default:
> + return csrno;
> + };
> +}
> +
> static RISCVException rmw_xiselect(CPURISCVState *env, int csrno,
> target_ulong *val, target_ulong new_val,
> target_ulong wr_mask)
> @@ -1935,7 +1994,7 @@ static RISCVException rmw_xiselect(CPURISCVState *env,
> int csrno,
> target_ulong *iselect;
>
> /* Translate CSR number for VS-mode */
> - csrno = aia_xlate_vs_csrno(env, csrno);
> + csrno = csrind_xlate_vs_csrno(env, csrno);
>
> /* Find the iselect CSR based on CSR number */
> switch (csrno) {
> @@ -1964,6 +2023,12 @@ static RISCVException rmw_xiselect(CPURISCVState *env,
> int csrno,
> return RISCV_EXCP_NONE;
> }
>
> +static bool xiselect_aia_range(target_ulong isel)
> +{
> + return (ISELECT_IPRIO0 <= isel && isel <= ISELECT_IPRIO15) ||
> + (ISELECT_IMSIC_FIRST <= isel && isel <= ISELECT_IMSIC_LAST);
> +}
> +
> static int rmw_iprio(target_ulong xlen,
> target_ulong iselect, uint8_t *iprio,
> target_ulong *val, target_ulong new_val,
> @@ -2009,45 +2074,44 @@ static int rmw_iprio(target_ulong xlen,
> return 0;
> }
>
> -static RISCVException rmw_xireg(CPURISCVState *env, int csrno,
> - target_ulong *val, target_ulong new_val,
> - target_ulong wr_mask)
> +static RISCVException rmw_xireg_aia(CPURISCVState *env, int csrno,
> + target_ulong isel, target_ulong *val,
> + target_ulong new_val, target_ulong wr_mask)
> {
> - bool virt, isel_reserved;
> - uint8_t *iprio;
> + bool virt = false, isel_reserved = false;
> int ret = -EINVAL;
> - target_ulong priv, isel, vgein;
> -
> - /* Translate CSR number for VS-mode */
> - csrno = aia_xlate_vs_csrno(env, csrno);
> + uint8_t *iprio;
> + target_ulong priv, vgein;
>
> - /* Decode register details from CSR number */
> - virt = false;
> - isel_reserved = false;
> + /* VS-mode CSR number passed in has already been translated */
> switch (csrno) {
> case CSR_MIREG:
> + if (!riscv_cpu_cfg(env)->ext_smaia) {
> + goto done;
> + }
> iprio = env->miprio;
> - isel = env->miselect;
> priv = PRV_M;
> break;
> case CSR_SIREG:
> - if (env->priv == PRV_S && env->mvien & MIP_SEIP &&
> + if (!riscv_cpu_cfg(env)->ext_ssaia ||
> + (env->priv == PRV_S && env->mvien & MIP_SEIP &&
> env->siselect >= ISELECT_IMSIC_EIDELIVERY &&
> - env->siselect <= ISELECT_IMSIC_EIE63) {
> + env->siselect <= ISELECT_IMSIC_EIE63)) {
> goto done;
> }
> iprio = env->siprio;
> - isel = env->siselect;
> priv = PRV_S;
> break;
> case CSR_VSIREG:
> + if (!riscv_cpu_cfg(env)->ext_ssaia) {
> + goto done;
> + }
> iprio = env->hviprio;
> - isel = env->vsiselect;
> priv = PRV_S;
> virt = true;
> break;
> default:
> - goto done;
> + goto done;
> };
>
> /* Find the selected guest interrupt file */
> @@ -2078,10 +2142,54 @@ static RISCVException rmw_xireg(CPURISCVState *env,
> int csrno,
> }
>
> done:
> + /*
> + * If AIA is not enabled, illegal instruction exception is always
> + * returned regardless of whether we are in VS-mode or not
> + */
> if (ret) {
> return (env->virt_enabled && virt && !isel_reserved) ?
> RISCV_EXCP_VIRT_INSTRUCTION_FAULT : RISCV_EXCP_ILLEGAL_INST;
> }
> +
> + return RISCV_EXCP_NONE;
> +}
> +
> +static RISCVException rmw_xireg(CPURISCVState *env, int csrno,
> + target_ulong *val, target_ulong new_val,
> + target_ulong wr_mask)
> +{
> + bool virt = false;
> + int ret = -EINVAL;
> + target_ulong isel;
> +
> + /* Translate CSR number for VS-mode */
> + csrno = csrind_xlate_vs_csrno(env, csrno);
> +
> + /* Decode register details from CSR number */
> + switch (csrno) {
> + case CSR_MIREG:
> + isel = env->miselect;
> + break;
> + case CSR_SIREG:
> + isel = env->siselect;
> + break;
> + case CSR_VSIREG:
> + isel = env->vsiselect;
> + virt = true;
> + break;
> + default:
> + goto done;
> + };
> +
> + if (xiselect_aia_range(isel)) {
> + return rmw_xireg_aia(env, csrno, isel, val, new_val, wr_mask);
> + }
> +
> +done:
> + if (ret) {
> + return (env->virt_enabled && virt) ?
> + RISCV_EXCP_VIRT_INSTRUCTION_FAULT : RISCV_EXCP_ILLEGAL_INST;
> + }
> return RISCV_EXCP_NONE;
> }
>
> @@ -4981,8 +5089,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
> [CSR_MIP] = { "mip", any, NULL, NULL, rmw_mip },
>
> /* Machine-Level Window to Indirectly Accessed Registers (AIA) */
> - [CSR_MISELECT] = { "miselect", aia_any, NULL, NULL, rmw_xiselect },
> - [CSR_MIREG] = { "mireg", aia_any, NULL, NULL, rmw_xireg },
> + [CSR_MISELECT] = { "miselect", csrind_or_aia_any, NULL, NULL,
> + rmw_xiselect },
> + [CSR_MIREG] = { "mireg", csrind_or_aia_any, NULL, NULL,
> + rmw_xireg },
>
> /* Machine-Level Interrupts (AIA) */
> [CSR_MTOPEI] = { "mtopei", aia_any, NULL, NULL, rmw_xtopei },
> @@ -5100,8 +5210,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
> [CSR_SATP] = { "satp", satp, read_satp, write_satp },
>
> /* Supervisor-Level Window to Indirectly Accessed Registers (AIA) */
> - [CSR_SISELECT] = { "siselect", aia_smode, NULL, NULL, rmw_xiselect },
> - [CSR_SIREG] = { "sireg", aia_smode, NULL, NULL, rmw_xireg },
> + [CSR_SISELECT] = { "siselect", csrind_or_aia_smode, NULL, NULL,
> + rmw_xiselect
> },
> + [CSR_SIREG] = { "sireg", csrind_or_aia_smode, NULL, NULL,
> + rmw_xireg
> },
>
> /* Supervisor-Level Interrupts (AIA) */
> [CSR_STOPEI] = { "stopei", aia_smode, NULL, NULL, rmw_xtopei },
> @@ -5180,9 +5292,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
> /*
> * VS-Level Window to Indirectly Accessed Registers (H-extension with
> AIA)
> */
> - [CSR_VSISELECT] = { "vsiselect", aia_hmode, NULL, NULL,
> - rmw_xiselect },
> - [CSR_VSIREG] = { "vsireg", aia_hmode, NULL, NULL, rmw_xireg },
> + [CSR_VSISELECT] = { "vsiselect", csrind_or_aia_hmode, NULL, NULL,
> + rmw_xiselect
> },
> + [CSR_VSIREG] = { "vsireg", csrind_or_aia_hmode, NULL, NULL,
> + rmw_xireg
> },
>
> /* VS-Level Interrupts (H-extension with AIA) */
> [CSR_VSTOPEI] = { "vstopei", aia_hmode, NULL, NULL, rmw_xtopei },
>
> --
> 2.34.1
>
>
