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Re: [PATCH v2 04/13] target/riscv: Support generic CSR indirect access
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From: |
Atish Kumar Patra |
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Subject: |
Re: [PATCH v2 04/13] target/riscv: Support generic CSR indirect access |
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Date: |
Wed, 7 Aug 2024 00:50:05 -0700 |
On Mon, Aug 5, 2024 at 5:15 PM Alistair Francis <alistair23@gmail.com> wrote:
>
> On Wed, Jul 24, 2024 at 9:32 AM Atish Patra <atishp@rivosinc.com> wrote:
> >
> > From: Kaiwen Xue <kaiwenx@rivosinc.com>
> >
> > This adds the indirect access registers required by sscsrind/smcsrind
> > and the operations on them. Note that xiselect and xireg are used for
> > both AIA and sxcsrind, and the behavior of accessing them depends on
> > whether each extension is enabled and the value stored in xiselect.
> >
> > Co-developed-by: Atish Patra <atishp@rivosinc.com>
> > Signed-off-by: Atish Patra <atishp@rivosinc.com>
> > Signed-off-by: Kaiwen Xue <kaiwenx@rivosinc.com>
> > ---
> > target/riscv/cpu.c | 2 +
> > target/riscv/cpu_bits.h | 28 ++++++++-
> > target/riscv/cpu_cfg.h | 2 +
> > target/riscv/csr.c | 149
> > ++++++++++++++++++++++++++++++++++++++++++++++--
> > 4 files changed, 175 insertions(+), 6 deletions(-)
> >
> > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> > index ebc19090b40d..ac2dce734d80 100644
> > --- a/target/riscv/cpu.c
> > +++ b/target/riscv/cpu.c
> > @@ -182,12 +182,14 @@ const RISCVIsaExtData isa_edata_arr[] = {
> > ISA_EXT_DATA_ENTRY(zhinx, PRIV_VERSION_1_12_0, ext_zhinx),
> > ISA_EXT_DATA_ENTRY(zhinxmin, PRIV_VERSION_1_12_0, ext_zhinxmin),
> > ISA_EXT_DATA_ENTRY(smaia, PRIV_VERSION_1_12_0, ext_smaia),
> > + ISA_EXT_DATA_ENTRY(smcdeleg, PRIV_VERSION_1_12_0, ext_smcdeleg),
> > ISA_EXT_DATA_ENTRY(smcntrpmf, PRIV_VERSION_1_12_0, ext_smcntrpmf),
> > ISA_EXT_DATA_ENTRY(smcsrind, PRIV_VERSION_1_12_0, ext_smcsrind),
> > ISA_EXT_DATA_ENTRY(smepmp, PRIV_VERSION_1_12_0, ext_smepmp),
> > ISA_EXT_DATA_ENTRY(smstateen, PRIV_VERSION_1_12_0, ext_smstateen),
> > ISA_EXT_DATA_ENTRY(ssaia, PRIV_VERSION_1_12_0, ext_ssaia),
> > ISA_EXT_DATA_ENTRY(ssccptr, PRIV_VERSION_1_11_0, has_priv_1_11),
> > + ISA_EXT_DATA_ENTRY(ssccfg, PRIV_VERSION_1_12_0, ext_ssccfg),
>
> Looks like these are in the wrong patch
>
Yes. Thanks for pointing it out. I will fix these in the next version.
> > ISA_EXT_DATA_ENTRY(sscofpmf, PRIV_VERSION_1_12_0, ext_sscofpmf),
> > ISA_EXT_DATA_ENTRY(sscounterenw, PRIV_VERSION_1_12_0, has_priv_1_12),
> > ISA_EXT_DATA_ENTRY(sscsrind, PRIV_VERSION_1_12_0, ext_sscsrind),
> > diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> > index 32b068f18aa5..2a8b53a6622e 100644
> > --- a/target/riscv/cpu_bits.h
> > +++ b/target/riscv/cpu_bits.h
> > @@ -170,6 +170,13 @@
> > #define CSR_MISELECT 0x350
> > #define CSR_MIREG 0x351
> >
> > +/* Machine Indirect Register Alias */
> > +#define CSR_MIREG2 0x352
> > +#define CSR_MIREG3 0x353
> > +#define CSR_MIREG4 0x355
> > +#define CSR_MIREG5 0x356
> > +#define CSR_MIREG6 0x357
> > +
> > /* Machine-Level Interrupts (AIA) */
> > #define CSR_MTOPEI 0x35c
> > #define CSR_MTOPI 0xfb0
> > @@ -219,6 +226,13 @@
> > #define CSR_SISELECT 0x150
> > #define CSR_SIREG 0x151
> >
> > +/* Supervisor Indirect Register Alias */
> > +#define CSR_SIREG2 0x152
> > +#define CSR_SIREG3 0x153
> > +#define CSR_SIREG4 0x155
> > +#define CSR_SIREG5 0x156
> > +#define CSR_SIREG6 0x157
> > +
> > /* Supervisor-Level Interrupts (AIA) */
> > #define CSR_STOPEI 0x15c
> > #define CSR_STOPI 0xdb0
> > @@ -285,6 +299,13 @@
> > #define CSR_VSISELECT 0x250
> > #define CSR_VSIREG 0x251
> >
> > +/* Virtual Supervisor Indirect Alias */
> > +#define CSR_VSIREG2 0x252
> > +#define CSR_VSIREG3 0x253
> > +#define CSR_VSIREG4 0x255
> > +#define CSR_VSIREG5 0x256
> > +#define CSR_VSIREG6 0x257
> > +
> > /* VS-Level Interrupts (H-extension with AIA) */
> > #define CSR_VSTOPEI 0x25c
> > #define CSR_VSTOPI 0xeb0
> > @@ -846,10 +867,13 @@ typedef enum RISCVException {
> > #define ISELECT_IMSIC_EIE63 0xff
> > #define ISELECT_IMSIC_FIRST ISELECT_IMSIC_EIDELIVERY
> > #define ISELECT_IMSIC_LAST ISELECT_IMSIC_EIE63
> > -#define ISELECT_MASK 0x1ff
> > +#define ISELECT_MASK_AIA 0x1ff
> > +
> > +/* MISELECT, SISELECT, and VSISELECT bits (AIA) */
> > +#define ISELECT_MASK_SXCSRIND 0xfff
> >
> > /* Dummy [M|S|VS]ISELECT value for emulating [M|S|VS]TOPEI CSRs */
> > -#define ISELECT_IMSIC_TOPEI (ISELECT_MASK + 1)
> > +#define ISELECT_IMSIC_TOPEI (ISELECT_MASK_AIA + 1)
> >
> > /* IMSIC bits (AIA) */
> > #define IMSIC_TOPEI_IID_SHIFT 16
> > diff --git a/target/riscv/cpu_cfg.h b/target/riscv/cpu_cfg.h
> > index b8a5174bc871..b2be3d47c7a3 100644
> > --- a/target/riscv/cpu_cfg.h
> > +++ b/target/riscv/cpu_cfg.h
> > @@ -79,6 +79,8 @@ struct RISCVCPUConfig {
> > bool ext_smcntrpmf;
> > bool ext_smcsrind;
> > bool ext_sscsrind;
> > + bool ext_smcdeleg;
> > + bool ext_ssccfg;
>
> Same here
>
> Alistair
>
> > bool ext_svadu;
> > bool ext_svinval;
> > bool ext_svnapot;
> > diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> > index 18b9ae802b15..4ae3931f0ada 100644
> > --- a/target/riscv/csr.c
> > +++ b/target/riscv/csr.c
> > @@ -287,6 +287,17 @@ static RISCVException aia_any32(CPURISCVState *env,
> > int csrno)
> > return any32(env, csrno);
> > }
> >
> > +static RISCVException csrind_any(CPURISCVState *env, int csrno)
> > +{
> > + RISCVCPU *cpu = env_archcpu(env);
> > +
> > + if (!cpu->cfg.ext_smcsrind) {
> > + return RISCV_EXCP_ILLEGAL_INST;
> > + }
> > +
> > + return RISCV_EXCP_NONE;
> > +}
> > +
> > static RISCVException csrind_or_aia_any(CPURISCVState *env, int csrno)
> > {
> > if (!riscv_cpu_cfg(env)->ext_smaia &&
> > !riscv_cpu_cfg(env)->ext_smcsrind) {
> > @@ -370,6 +381,15 @@ static bool
> > csrind_or_aia_extensions_present(CPURISCVState *env)
> > return csrind_extensions_present(env) || aia_extensions_present(env);
> > }
> >
> > +static RISCVException csrind_smode(CPURISCVState *env, int csrno)
> > +{
> > + if (!csrind_extensions_present(env)) {
> > + return RISCV_EXCP_ILLEGAL_INST;
> > + }
> > +
> > + return smode(env, csrno);
> > +}
> > +
> > static RISCVException csrind_or_aia_smode(CPURISCVState *env, int csrno)
> > {
> > if (!csrind_or_aia_extensions_present(env)) {
> > @@ -398,6 +418,15 @@ static RISCVException hmode32(CPURISCVState *env, int
> > csrno)
> >
> > }
> >
> > +static RISCVException csrind_hmode(CPURISCVState *env, int csrno)
> > +{
> > + if (!csrind_extensions_present(env)) {
> > + return RISCV_EXCP_ILLEGAL_INST;
> > + }
> > +
> > + return hmode(env, csrno);
> > +}
> > +
> > static RISCVException csrind_or_aia_hmode(CPURISCVState *env, int csrno)
> > {
> > if (!csrind_or_aia_extensions_present(env)) {
> > @@ -2027,7 +2056,12 @@ static int csrind_xlate_vs_csrno(CPURISCVState *env,
> > int csrno)
> > case CSR_SISELECT:
> > return CSR_VSISELECT;
> > case CSR_SIREG:
> > - return CSR_VSIREG;
> > + case CSR_SIREG2:
> > + case CSR_SIREG3:
> > + case CSR_SIREG4:
> > + case CSR_SIREG5:
> > + case CSR_SIREG6:
> > + return CSR_VSIREG + (csrno - CSR_SIREG);
> > default:
> > return csrno;
> > };
> > @@ -2067,7 +2101,12 @@ static RISCVException rmw_xiselect(CPURISCVState
> > *env, int csrno,
> > *val = *iselect;
> > }
> >
> > - wr_mask &= ISELECT_MASK;
> > + if (riscv_cpu_cfg(env)->ext_smcsrind ||
> > riscv_cpu_cfg(env)->ext_sscsrind) {
> > + wr_mask &= ISELECT_MASK_SXCSRIND;
> > + } else {
> > + wr_mask &= ISELECT_MASK_AIA;
> > + }
> > +
> > if (wr_mask) {
> > *iselect = (*iselect & ~wr_mask) | (new_val & wr_mask);
> > }
> > @@ -2206,6 +2245,59 @@ done:
> > return RISCV_EXCP_NONE;
> > }
> >
> > +/*
> > + * rmw_xireg_csrind: Perform indirect access to xireg and xireg2-xireg6
> > + *
> > + * Perform indirect access to xireg and xireg2-xireg6.
> > + * This is a generic interface for all xireg CSRs. Apart from AIA, all
> > other
> > + * extension using csrind should be implemented here.
> > + */
> > +static int rmw_xireg_csrind(CPURISCVState *env, int csrno,
> > + target_ulong isel, target_ulong *val,
> > + target_ulong new_val, target_ulong wr_mask)
> > +{
> > + return -EINVAL;
> > +}
> > +
> > +static int rmw_xiregi(CPURISCVState *env, int csrno, target_ulong *val,
> > + target_ulong new_val, target_ulong wr_mask)
> > +{
> > + bool virt = false;
> > + int ret = -EINVAL;
> > + target_ulong isel;
> > +
> > + ret = smstateen_acc_ok(env, 0, SMSTATEEN0_SVSLCT);
> > + if (ret != RISCV_EXCP_NONE) {
> > + return ret;
> > + }
> > +
> > + /* Translate CSR number for VS-mode */
> > + csrno = csrind_xlate_vs_csrno(env, csrno);
> > +
> > + if (CSR_MIREG <= csrno && csrno <= CSR_MIREG6 &&
> > + csrno != CSR_MIREG4 - 1) {
> > + isel = env->miselect;
> > + } else if (CSR_SIREG <= csrno && csrno <= CSR_SIREG6 &&
> > + csrno != CSR_SIREG4 - 1) {
> > + isel = env->siselect;
> > + } else if (CSR_VSIREG <= csrno && csrno <= CSR_VSIREG6 &&
> > + csrno != CSR_VSIREG4 - 1) {
> > + isel = env->vsiselect;
> > + virt = true;
> > + } else {
> > + goto done;
> > + }
> > +
> > + return rmw_xireg_csrind(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;
> > +}
> > +
> > static RISCVException rmw_xireg(CPURISCVState *env, int csrno,
> > target_ulong *val, target_ulong new_val,
> > target_ulong wr_mask)
> > @@ -2238,8 +2330,21 @@ static RISCVException rmw_xireg(CPURISCVState *env,
> > int csrno,
> > goto done;
> > };
> >
> > + /*
> > + * Use the xiselect range to determine actual op on xireg.
> > + *
> > + * Since we only checked the existence of AIA or Indirect Access in the
> > + * predicate, we should check the existence of the exact extension when
> > + * we get to a specific range and return illegal instruction exception
> > even
> > + * in VS-mode.
> > + */
> > if (xiselect_aia_range(isel)) {
> > return rmw_xireg_aia(env, csrno, isel, val, new_val, wr_mask);
> > + } else if (riscv_cpu_cfg(env)->ext_smcsrind ||
> > + riscv_cpu_cfg(env)->ext_sscsrind) {
> > + return rmw_xireg_csrind(env, csrno, isel, val, new_val, wr_mask);
> > + } else {
> > + return RISCV_EXCP_ILLEGAL_INST;
> > }
> >
> > done:
> > @@ -2671,7 +2776,7 @@ static RISCVException write_mstateen0(CPURISCVState
> > *env, int csrno,
> > * TODO: Do we need to check ssaia as well ? Can we enable ssaia
> > without
> > * smaia ?
> > */
> > - if (riscv_cpu_cfg(env)->ext_smaia) {
> > + if (riscv_cpu_cfg(env)->ext_smaia || riscv_cpu_cfg(env)->ext_smcsrind)
> > {
> > wr_mask |= SMSTATEEN0_SVSLCT;
> > }
> >
> > @@ -2764,7 +2869,7 @@ static RISCVException write_hstateen0(CPURISCVState
> > *env, int csrno,
> > wr_mask |= SMSTATEEN0_FCSR;
> > }
> >
> > - if (riscv_cpu_cfg(env)->ext_ssaia) {
> > + if (riscv_cpu_cfg(env)->ext_ssaia || riscv_cpu_cfg(env)->ext_sscsrind)
> > {
> > wr_mask |= SMSTATEEN0_SVSLCT;
> > }
> >
> > @@ -5180,6 +5285,18 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
> > [CSR_MIREG] = { "mireg", csrind_or_aia_any, NULL, NULL,
> > rmw_xireg },
> >
> > + /* Machine Indirect Register Alias */
> > + [CSR_MIREG2] = { "mireg2", csrind_any, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0 },
> > + [CSR_MIREG3] = { "mireg3", csrind_any, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0 },
> > + [CSR_MIREG4] = { "mireg4", csrind_any, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0 },
> > + [CSR_MIREG5] = { "mireg5", csrind_any, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0 },
> > + [CSR_MIREG6] = { "mireg6", csrind_any, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0 },
> > +
> > /* Machine-Level Interrupts (AIA) */
> > [CSR_MTOPEI] = { "mtopei", aia_any, NULL, NULL, rmw_xtopei },
> > [CSR_MTOPI] = { "mtopi", aia_any, read_mtopi },
> > @@ -5301,6 +5418,18 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
> > [CSR_SIREG] = { "sireg", csrind_or_aia_smode, NULL, NULL,
> > rmw_xireg
> > },
> >
> > + /* Supervisor Indirect Register Alias */
> > + [CSR_SIREG2] = { "sireg2", csrind_smode, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0
> > },
> > + [CSR_SIREG3] = { "sireg3", csrind_smode, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0
> > },
> > + [CSR_SIREG4] = { "sireg4", csrind_smode, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0
> > },
> > + [CSR_SIREG5] = { "sireg5", csrind_smode, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0
> > },
> > + [CSR_SIREG6] = { "sireg6", csrind_smode, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0
> > },
> > +
> > /* Supervisor-Level Interrupts (AIA) */
> > [CSR_STOPEI] = { "stopei", aia_smode, NULL, NULL, rmw_xtopei },
> > [CSR_STOPI] = { "stopi", aia_smode, read_stopi },
> > @@ -5383,6 +5512,18 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
> > [CSR_VSIREG] = { "vsireg", csrind_or_aia_hmode, NULL, NULL,
> > rmw_xireg
> > },
> >
> > + /* Virtual Supervisor Indirect Alias */
> > + [CSR_VSIREG2] = { "vsireg2", csrind_hmode, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0
> > },
> > + [CSR_VSIREG3] = { "vsireg3", csrind_hmode, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0
> > },
> > + [CSR_VSIREG4] = { "vsireg4", csrind_hmode, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0
> > },
> > + [CSR_VSIREG5] = { "vsireg5", csrind_hmode, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0
> > },
> > + [CSR_VSIREG6] = { "vsireg6", csrind_hmode, NULL, NULL, rmw_xiregi,
> > + .min_priv_ver = PRIV_VERSION_1_12_0
> > },
> > +
> > /* VS-Level Interrupts (H-extension with AIA) */
> > [CSR_VSTOPEI] = { "vstopei", aia_hmode, NULL, NULL, rmw_xtopei
> > },
> > [CSR_VSTOPI] = { "vstopi", aia_hmode, read_vstopi },
> >
> > --
> > 2.34.1
> >
> >