diff mbox series

[v8,14/23] target/riscv: Implement AIA xiselect and xireg CSRs

Message ID 20220119152614.27548-15-anup@brainfault.org (mailing list archive)
State New, archived
Headers show
Series QEMU RISC-V AIA support | expand

Commit Message

Anup Patel Jan. 19, 2022, 3:26 p.m. UTC 
From: Anup Patel <anup.patel@wdc.com>

The AIA specification defines [m|s|vs]iselect and [m|s|vs]ireg CSRs
which allow indirect access to interrupt priority arrays and per-HART
IMSIC registers. This patch implements AIA xiselect and xireg CSRs.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
---
 target/riscv/cpu.h     |   7 ++
 target/riscv/csr.c     | 175 +++++++++++++++++++++++++++++++++++++++++
 target/riscv/machine.c |   3 +
 3 files changed, 185 insertions(+)

Comments

Alistair Francis Jan. 20, 2022, 11:59 p.m. UTC | #1 
On Thu, Jan 20, 2022 at 2:32 AM Anup Patel <anup@brainfault.org> wrote:
>
> From: Anup Patel <anup.patel@wdc.com>
>
> The AIA specification defines [m|s|vs]iselect and [m|s|vs]ireg CSRs
> which allow indirect access to interrupt priority arrays and per-HART
> IMSIC registers. This patch implements AIA xiselect and xireg CSRs.
>
> Signed-off-by: Anup Patel <anup.patel@wdc.com>
> Signed-off-by: Anup Patel <anup@brainfault.org>
> Reviewed-by: Frank Chang <frank.chang@sifive.com>

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

Alistair

> ---
>  target/riscv/cpu.h     |   7 ++
>  target/riscv/csr.c     | 175 +++++++++++++++++++++++++++++++++++++++++
>  target/riscv/machine.c |   3 +
>  3 files changed, 185 insertions(+)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 65ffd31801..058ea9ce99 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -195,6 +195,10 @@ struct CPURISCVState {
>      uint8_t miprio[64];
>      uint8_t siprio[64];
>
> +    /* AIA CSRs */
> +    target_ulong miselect;
> +    target_ulong siselect;
> +
>      /* Hypervisor CSRs */
>      target_ulong hstatus;
>      target_ulong hedeleg;
> @@ -228,6 +232,9 @@ struct CPURISCVState {
>      target_ulong vstval;
>      target_ulong vsatp;
>
> +    /* AIA VS-mode CSRs */
> +    target_ulong vsiselect;
> +
>      target_ulong mtval2;
>      target_ulong mtinst;
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index f7904c003f..e40620f455 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -916,6 +916,169 @@ static int read_mtopi(CPURISCVState *env, int csrno, target_ulong *val)
>      return RISCV_EXCP_NONE;
>  }
>
> +static int aia_xlate_vs_csrno(CPURISCVState *env, int csrno)
> +{
> +    if (!riscv_cpu_virt_enabled(env)) {
> +        return csrno;
> +    }
> +
> +    switch (csrno) {
> +    case CSR_SISELECT:
> +        return CSR_VSISELECT;
> +    case CSR_SIREG:
> +        return CSR_VSIREG;
> +    default:
> +        return csrno;
> +    };
> +}
> +
> +static int rmw_xiselect(CPURISCVState *env, int csrno, target_ulong *val,
> +                        target_ulong new_val, target_ulong wr_mask)
> +{
> +    target_ulong *iselect;
> +
> +    /* Translate CSR number for VS-mode */
> +    csrno = aia_xlate_vs_csrno(env, csrno);
> +
> +    /* Find the iselect CSR based on CSR number */
> +    switch (csrno) {
> +    case CSR_MISELECT:
> +        iselect = &env->miselect;
> +        break;
> +    case CSR_SISELECT:
> +        iselect = &env->siselect;
> +        break;
> +    case CSR_VSISELECT:
> +        iselect = &env->vsiselect;
> +        break;
> +    default:
> +         return RISCV_EXCP_ILLEGAL_INST;
> +    };
> +
> +    if (val) {
> +        *val = *iselect;
> +    }
> +
> +    wr_mask &= ISELECT_MASK;
> +    if (wr_mask) {
> +        *iselect = (*iselect & ~wr_mask) | (new_val & wr_mask);
> +    }
> +
> +    return RISCV_EXCP_NONE;
> +}
> +
> +static int rmw_iprio(target_ulong xlen,
> +                     target_ulong iselect, uint8_t *iprio,
> +                     target_ulong *val, target_ulong new_val,
> +                     target_ulong wr_mask, int ext_irq_no)
> +{
> +    int i, firq, nirqs;
> +    target_ulong old_val;
> +
> +    if (iselect < ISELECT_IPRIO0 || ISELECT_IPRIO15 < iselect) {
> +        return -EINVAL;
> +    }
> +    if (xlen != 32 && iselect & 0x1) {
> +        return -EINVAL;
> +    }
> +
> +    nirqs = 4 * (xlen / 32);
> +    firq = ((iselect - ISELECT_IPRIO0) / (xlen / 32)) * (nirqs);
> +
> +    old_val = 0;
> +    for (i = 0; i < nirqs; i++) {
> +        old_val |= ((target_ulong)iprio[firq + i]) << (IPRIO_IRQ_BITS * i);
> +    }
> +
> +    if (val) {
> +        *val = old_val;
> +    }
> +
> +    if (wr_mask) {
> +        new_val = (old_val & ~wr_mask) | (new_val & wr_mask);
> +        for (i = 0; i < nirqs; i++) {
> +            /*
> +             * M-level and S-level external IRQ priority always read-only
> +             * zero. This means default priority order is always preferred
> +             * for M-level and S-level external IRQs.
> +             */
> +            if ((firq + i) == ext_irq_no) {
> +                continue;
> +            }
> +            iprio[firq + i] = (new_val >> (IPRIO_IRQ_BITS * i)) & 0xff;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +static int rmw_xireg(CPURISCVState *env, int csrno, target_ulong *val,
> +                     target_ulong new_val, target_ulong wr_mask)
> +{
> +    bool virt;
> +    uint8_t *iprio;
> +    int ret = -EINVAL;
> +    target_ulong priv, isel, vgein;
> +
> +    /* Translate CSR number for VS-mode */
> +    csrno = aia_xlate_vs_csrno(env, csrno);
> +
> +    /* Decode register details from CSR number */
> +    virt = false;
> +    switch (csrno) {
> +    case CSR_MIREG:
> +        iprio = env->miprio;
> +        isel = env->miselect;
> +        priv = PRV_M;
> +        break;
> +    case CSR_SIREG:
> +        iprio = env->siprio;
> +        isel = env->siselect;
> +        priv = PRV_S;
> +        break;
> +    case CSR_VSIREG:
> +        iprio = env->hviprio;
> +        isel = env->vsiselect;
> +        priv = PRV_S;
> +        virt = true;
> +        break;
> +    default:
> +         goto done;
> +    };
> +
> +    /* Find the selected guest interrupt file */
> +    vgein = (virt) ? get_field(env->hstatus, HSTATUS_VGEIN) : 0;
> +
> +    if (ISELECT_IPRIO0 <= isel && isel <= ISELECT_IPRIO15) {
> +        /* Local interrupt priority registers not available for VS-mode */
> +        if (!virt) {
> +            ret = rmw_iprio(riscv_cpu_mxl_bits(env),
> +                            isel, iprio, val, new_val, wr_mask,
> +                            (priv == PRV_M) ? IRQ_M_EXT : IRQ_S_EXT);
> +        }
> +    } else if (ISELECT_IMSIC_FIRST <= isel && isel <= ISELECT_IMSIC_LAST) {
> +        /* IMSIC registers only available when machine implements it. */
> +        if (env->aia_ireg_rmw_fn[priv]) {
> +            /* Selected guest interrupt file should not be zero */
> +            if (virt && (!vgein || env->geilen < vgein)) {
> +                goto done;
> +            }
> +            /* Call machine specific IMSIC register emulation */
> +            ret = env->aia_ireg_rmw_fn[priv](env->aia_ireg_rmw_fn_arg[priv],
> +                                    AIA_MAKE_IREG(isel, priv, virt, vgein,
> +                                                  riscv_cpu_mxl_bits(env)),
> +                                    val, new_val, wr_mask);
> +        }
> +    }
> +
> +done:
> +    if (ret) {
> +        return (riscv_cpu_virt_enabled(env) && virt) ?
> +               RISCV_EXCP_VIRT_INSTRUCTION_FAULT : RISCV_EXCP_ILLEGAL_INST;
> +    }
> +    return RISCV_EXCP_NONE;
> +}
> +
>  static RISCVException read_mtvec(CPURISCVState *env, int csrno,
>                                   target_ulong *val)
>  {
> @@ -2690,6 +2853,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
>      [CSR_MTVAL]    = { "mtval",    any,  read_mtval,    write_mtval    },
>      [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 },
> +
>      /* Machine-Level Interrupts (AIA) */
>      [CSR_MTOPI]    = { "mtopi",    aia_any,   read_mtopi },
>
> @@ -2722,6 +2889,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
>      /* Supervisor Protection and Translation */
>      [CSR_SATP]     = { "satp",     smode, 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 },
> +
>      /* Supervisor-Level Interrupts (AIA) */
>      [CSR_STOPI]      = { "stopi",      aia_smode, read_stopi },
>
> @@ -2763,6 +2934,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
>      [CSR_HVIPRIO1]    = { "hviprio1",    aia_hmode, read_hviprio1,   write_hviprio1 },
>      [CSR_HVIPRIO2]    = { "hviprio2",    aia_hmode, read_hviprio2,   write_hviprio2 },
>
> +    /* 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 },
> +
>      /* VS-Level Interrupts (H-extension with AIA) */
>      [CSR_VSTOPI]      = { "vstopi",      aia_hmode, read_vstopi },
>
> diff --git a/target/riscv/machine.c b/target/riscv/machine.c
> index c6a01ba953..9895930b29 100644
> --- a/target/riscv/machine.c
> +++ b/target/riscv/machine.c
> @@ -103,6 +103,7 @@ static const VMStateDescription vmstate_hyper = {
>          VMSTATE_UINTTL(env.vscause, RISCVCPU),
>          VMSTATE_UINTTL(env.vstval, RISCVCPU),
>          VMSTATE_UINTTL(env.vsatp, RISCVCPU),
> +        VMSTATE_UINTTL(env.vsiselect, RISCVCPU),
>
>          VMSTATE_UINTTL(env.mtval2, RISCVCPU),
>          VMSTATE_UINTTL(env.mtinst, RISCVCPU),
> @@ -260,6 +261,8 @@ const VMStateDescription vmstate_riscv_cpu = {
>          VMSTATE_UINTTL(env.mepc, RISCVCPU),
>          VMSTATE_UINTTL(env.mcause, RISCVCPU),
>          VMSTATE_UINTTL(env.mtval, RISCVCPU),
> +        VMSTATE_UINTTL(env.miselect, RISCVCPU),
> +        VMSTATE_UINTTL(env.siselect, RISCVCPU),
>          VMSTATE_UINTTL(env.scounteren, RISCVCPU),
>          VMSTATE_UINTTL(env.mcounteren, RISCVCPU),
>          VMSTATE_UINTTL(env.sscratch, RISCVCPU),
> --
> 2.25.1
>
>
diff mbox series

Patch

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 65ffd31801..058ea9ce99 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -195,6 +195,10 @@  struct CPURISCVState {
     uint8_t miprio[64];
     uint8_t siprio[64];
 
+    /* AIA CSRs */
+    target_ulong miselect;
+    target_ulong siselect;
+
     /* Hypervisor CSRs */
     target_ulong hstatus;
     target_ulong hedeleg;
@@ -228,6 +232,9 @@  struct CPURISCVState {
     target_ulong vstval;
     target_ulong vsatp;
 
+    /* AIA VS-mode CSRs */
+    target_ulong vsiselect;
+
     target_ulong mtval2;
     target_ulong mtinst;
 
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index f7904c003f..e40620f455 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -916,6 +916,169 @@  static int read_mtopi(CPURISCVState *env, int csrno, target_ulong *val)
     return RISCV_EXCP_NONE;
 }
 
+static int aia_xlate_vs_csrno(CPURISCVState *env, int csrno)
+{
+    if (!riscv_cpu_virt_enabled(env)) {
+        return csrno;
+    }
+
+    switch (csrno) {
+    case CSR_SISELECT:
+        return CSR_VSISELECT;
+    case CSR_SIREG:
+        return CSR_VSIREG;
+    default:
+        return csrno;
+    };
+}
+
+static int rmw_xiselect(CPURISCVState *env, int csrno, target_ulong *val,
+                        target_ulong new_val, target_ulong wr_mask)
+{
+    target_ulong *iselect;
+
+    /* Translate CSR number for VS-mode */
+    csrno = aia_xlate_vs_csrno(env, csrno);
+
+    /* Find the iselect CSR based on CSR number */
+    switch (csrno) {
+    case CSR_MISELECT:
+        iselect = &env->miselect;
+        break;
+    case CSR_SISELECT:
+        iselect = &env->siselect;
+        break;
+    case CSR_VSISELECT:
+        iselect = &env->vsiselect;
+        break;
+    default:
+         return RISCV_EXCP_ILLEGAL_INST;
+    };
+
+    if (val) {
+        *val = *iselect;
+    }
+
+    wr_mask &= ISELECT_MASK;
+    if (wr_mask) {
+        *iselect = (*iselect & ~wr_mask) | (new_val & wr_mask);
+    }
+
+    return RISCV_EXCP_NONE;
+}
+
+static int rmw_iprio(target_ulong xlen,
+                     target_ulong iselect, uint8_t *iprio,
+                     target_ulong *val, target_ulong new_val,
+                     target_ulong wr_mask, int ext_irq_no)
+{
+    int i, firq, nirqs;
+    target_ulong old_val;
+
+    if (iselect < ISELECT_IPRIO0 || ISELECT_IPRIO15 < iselect) {
+        return -EINVAL;
+    }
+    if (xlen != 32 && iselect & 0x1) {
+        return -EINVAL;
+    }
+
+    nirqs = 4 * (xlen / 32);
+    firq = ((iselect - ISELECT_IPRIO0) / (xlen / 32)) * (nirqs);
+
+    old_val = 0;
+    for (i = 0; i < nirqs; i++) {
+        old_val |= ((target_ulong)iprio[firq + i]) << (IPRIO_IRQ_BITS * i);
+    }
+
+    if (val) {
+        *val = old_val;
+    }
+
+    if (wr_mask) {
+        new_val = (old_val & ~wr_mask) | (new_val & wr_mask);
+        for (i = 0; i < nirqs; i++) {
+            /*
+             * M-level and S-level external IRQ priority always read-only
+             * zero. This means default priority order is always preferred
+             * for M-level and S-level external IRQs.
+             */
+            if ((firq + i) == ext_irq_no) {
+                continue;
+            }
+            iprio[firq + i] = (new_val >> (IPRIO_IRQ_BITS * i)) & 0xff;
+        }
+    }
+
+    return 0;
+}
+
+static int rmw_xireg(CPURISCVState *env, int csrno, target_ulong *val,
+                     target_ulong new_val, target_ulong wr_mask)
+{
+    bool virt;
+    uint8_t *iprio;
+    int ret = -EINVAL;
+    target_ulong priv, isel, vgein;
+
+    /* Translate CSR number for VS-mode */
+    csrno = aia_xlate_vs_csrno(env, csrno);
+
+    /* Decode register details from CSR number */
+    virt = false;
+    switch (csrno) {
+    case CSR_MIREG:
+        iprio = env->miprio;
+        isel = env->miselect;
+        priv = PRV_M;
+        break;
+    case CSR_SIREG:
+        iprio = env->siprio;
+        isel = env->siselect;
+        priv = PRV_S;
+        break;
+    case CSR_VSIREG:
+        iprio = env->hviprio;
+        isel = env->vsiselect;
+        priv = PRV_S;
+        virt = true;
+        break;
+    default:
+         goto done;
+    };
+
+    /* Find the selected guest interrupt file */
+    vgein = (virt) ? get_field(env->hstatus, HSTATUS_VGEIN) : 0;
+
+    if (ISELECT_IPRIO0 <= isel && isel <= ISELECT_IPRIO15) {
+        /* Local interrupt priority registers not available for VS-mode */
+        if (!virt) {
+            ret = rmw_iprio(riscv_cpu_mxl_bits(env),
+                            isel, iprio, val, new_val, wr_mask,
+                            (priv == PRV_M) ? IRQ_M_EXT : IRQ_S_EXT);
+        }
+    } else if (ISELECT_IMSIC_FIRST <= isel && isel <= ISELECT_IMSIC_LAST) {
+        /* IMSIC registers only available when machine implements it. */
+        if (env->aia_ireg_rmw_fn[priv]) {
+            /* Selected guest interrupt file should not be zero */
+            if (virt && (!vgein || env->geilen < vgein)) {
+                goto done;
+            }
+            /* Call machine specific IMSIC register emulation */
+            ret = env->aia_ireg_rmw_fn[priv](env->aia_ireg_rmw_fn_arg[priv],
+                                    AIA_MAKE_IREG(isel, priv, virt, vgein,
+                                                  riscv_cpu_mxl_bits(env)),
+                                    val, new_val, wr_mask);
+        }
+    }
+
+done:
+    if (ret) {
+        return (riscv_cpu_virt_enabled(env) && virt) ?
+               RISCV_EXCP_VIRT_INSTRUCTION_FAULT : RISCV_EXCP_ILLEGAL_INST;
+    }
+    return RISCV_EXCP_NONE;
+}
+
 static RISCVException read_mtvec(CPURISCVState *env, int csrno,
                                  target_ulong *val)
 {
@@ -2690,6 +2853,10 @@  riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_MTVAL]    = { "mtval",    any,  read_mtval,    write_mtval    },
     [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 },
+
     /* Machine-Level Interrupts (AIA) */
     [CSR_MTOPI]    = { "mtopi",    aia_any,   read_mtopi },
 
@@ -2722,6 +2889,10 @@  riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     /* Supervisor Protection and Translation */
     [CSR_SATP]     = { "satp",     smode, 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 },
+
     /* Supervisor-Level Interrupts (AIA) */
     [CSR_STOPI]      = { "stopi",      aia_smode, read_stopi },
 
@@ -2763,6 +2934,10 @@  riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_HVIPRIO1]    = { "hviprio1",    aia_hmode, read_hviprio1,   write_hviprio1 },
     [CSR_HVIPRIO2]    = { "hviprio2",    aia_hmode, read_hviprio2,   write_hviprio2 },
 
+    /* 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 },
+
     /* VS-Level Interrupts (H-extension with AIA) */
     [CSR_VSTOPI]      = { "vstopi",      aia_hmode, read_vstopi },
 
diff --git a/target/riscv/machine.c b/target/riscv/machine.c
index c6a01ba953..9895930b29 100644
--- a/target/riscv/machine.c
+++ b/target/riscv/machine.c
@@ -103,6 +103,7 @@  static const VMStateDescription vmstate_hyper = {
         VMSTATE_UINTTL(env.vscause, RISCVCPU),
         VMSTATE_UINTTL(env.vstval, RISCVCPU),
         VMSTATE_UINTTL(env.vsatp, RISCVCPU),
+        VMSTATE_UINTTL(env.vsiselect, RISCVCPU),
 
         VMSTATE_UINTTL(env.mtval2, RISCVCPU),
         VMSTATE_UINTTL(env.mtinst, RISCVCPU),
@@ -260,6 +261,8 @@  const VMStateDescription vmstate_riscv_cpu = {
         VMSTATE_UINTTL(env.mepc, RISCVCPU),
         VMSTATE_UINTTL(env.mcause, RISCVCPU),
         VMSTATE_UINTTL(env.mtval, RISCVCPU),
+        VMSTATE_UINTTL(env.miselect, RISCVCPU),
+        VMSTATE_UINTTL(env.siselect, RISCVCPU),
         VMSTATE_UINTTL(env.scounteren, RISCVCPU),
         VMSTATE_UINTTL(env.mcounteren, RISCVCPU),
         VMSTATE_UINTTL(env.sscratch, RISCVCPU),