RE: [PATCH v3 2/5] target/mips: Add support for MIPS<32|64>R6 CRC32 ISA

[Taylor Simpson <tsimpson@quicinc.com>]

> From: Aleksandar Markovic <amarkovic@wavecomp.com>
>
> Add support for eight CRC-related MIPS<32|64>R6 instructions.
>
> Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
> ---
>  disas/mips.c            |   8 +++
>  target/mips/helper.h    |   2 +
>  target/mips/op_helper.c |  19 ++++++++
>  target/mips/translate.c | 127
> ++++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 156 insertions(+)
>
> diff --git a/disas/mips.c b/disas/mips.c index dfefe5e..75c48b3 100644
> --- a/disas/mips.c
> +++ b/disas/mips.c
> @@ -1409,6 +1409,14 @@ const struct mips_opcode mips_builtin_opcodes[]
> =
>  {"dvp",        "t",     0x41600024, 0xffe0ffff, TRAP|WR_t,            0, I32R6},
>  {"evp",        "",      0x41600004, 0xffffffff, TRAP,                 0, I32R6},
>  {"evp",        "t",     0x41600004, 0xffe0ffff, TRAP|WR_t,            0, I32R6},
> +{"crc32b",     "t,v,t", 0x7c00000f, 0xfc00ff3f, WR_d | RD_s | RD_t,   0, I32R6},
> +{"crc32h",     "t,v,t", 0x7c00004f, 0xfc00ff3f, WR_d | RD_s | RD_t,   0, I32R6},
> +{"crc32w",     "t,v,t", 0x7c00008f, 0xfc00ff3f, WR_d | RD_s | RD_t,   0, I32R6},
> +{"crc32d",     "t,v,t", 0x7c0000cf, 0xfc00ff3f, WR_d | RD_s | RD_t,   0, I64R6},
> +{"crc32cb",    "t,v,t", 0x7c00010f, 0xfc00ff3f, WR_d | RD_s | RD_t,   0, I32R6},
> +{"crc32ch",    "t,v,t", 0x7c00014f, 0xfc00ff3f, WR_d | RD_s | RD_t,   0, I32R6},
> +{"crc32cw",    "t,v,t", 0x7c00018f, 0xfc00ff3f, WR_d | RD_s | RD_t,   0, I32R6},
> +{"crc32cd",    "t,v,t", 0x7c0001cf, 0xfc00ff3f, WR_d | RD_s | RD_t,   0, I64R6},
>
>  /* MSA */
>  {"sll.b",   "+d,+e,+f", 0x7800000d, 0xffe0003f, WR_VD|RD_VS|RD_VT,  0,
> MSA},
> diff --git a/target/mips/helper.h b/target/mips/helper.h index
> 7b8ad74..2095330 100644
> --- a/target/mips/helper.h
> +++ b/target/mips/helper.h
> @@ -40,6 +40,8 @@ DEF_HELPER_FLAGS_1(bitswap,
> TCG_CALL_NO_RWG_SE, tl, tl)  DEF_HELPER_FLAGS_1(dbitswap,
> TCG_CALL_NO_RWG_SE, tl, tl)  #endif
>
> +DEF_HELPER_3(crc32, tl, tl, tl, i32)
> +DEF_HELPER_3(crc32c, tl, tl, tl, i32)
>  DEF_HELPER_FLAGS_4(rotx, TCG_CALL_NO_RWG_SE, tl, tl, i32, i32, i32)
>
>  #ifndef CONFIG_USER_ONLY
> diff --git a/target/mips/op_helper.c b/target/mips/op_helper.c index
> 18fcee4..5cd396d 100644
> --- a/target/mips/op_helper.c
> +++ b/target/mips/op_helper.c
> @@ -27,6 +27,8 @@
>  #include "exec/memop.h"
>  #include "sysemu/kvm.h"
>  #include "fpu/softfloat.h"
> +#include "qemu/crc32c.h"
> +#include <zlib.h>
>
>
> /**********************************************************
> *******************/
>  /* Exceptions processing helpers */
> @@ -350,6 +352,23 @@ target_ulong helper_rotx(target_ulong rs, uint32_t
> shift, uint32_t shiftx,
>      return (int64_t)(int32_t)(uint32_t)tmp5;  }
>
> +/* these crc32 functions are based on target/arm/helper-a64.c */
> +target_ulong helper_crc32(target_ulong val, target_ulong m, uint32_t

Shouldn't this be "HELPER(crc32)"?

> +sz) {
> +    uint8_t buf[8];
> +
> +    stq_le_p(buf, m);
> +    return (int32_t) (crc32(val ^ 0xffffffff, buf, sz) ^ 0xffffffff); }
> +
> +target_ulong helper_crc32c(target_ulong val, target_ulong m, uint32_t

Shouldn't this be "HELPER(crc32c)"?

> +sz) {
> +    uint8_t buf[8];
> +
> +    stq_le_p(buf, m);
> +    return (int32_t) (crc32c(val, buf, sz) ^ 0xffffffff); }
> +
>  #ifndef CONFIG_USER_ONLY
>
>  static inline hwaddr do_translate_address(CPUMIPSState *env, diff --git
> a/target/mips/translate.c b/target/mips/translate.c index 4bff585..1b38356
> 100644
> --- a/target/mips/translate.c
> +++ b/target/mips/translate.c
> @@ -451,6 +451,7 @@ enum {
>      OPC_LWE            = 0x2F | OPC_SPECIAL3,
>
>      /* R6 */
> +    OPC_CRC32          = 0x0F | OPC_SPECIAL3,
>      R6_OPC_PREF        = 0x35 | OPC_SPECIAL3,
>      R6_OPC_CACHE       = 0x25 | OPC_SPECIAL3,
>      R6_OPC_LL          = 0x36 | OPC_SPECIAL3,
> @@ -2547,6 +2548,7 @@ typedef struct DisasContext {
>      bool nan2008;
>      bool abs2008;
>      bool saar;
> +    bool crcp;
>  } DisasContext;
>
>  #define DISAS_STOP       DISAS_TARGET_0
> @@ -27117,11 +27119,96 @@ static void
> decode_opc_special2_legacy(CPUMIPSState *env, DisasContext *ctx)
>      }
>  }
>
> +static void gen_crc32(DisasContext *ctx, int rd, int rs, int rt, int sz,
> +                      int crc32c)
> +{
> +    TCGv t0;
> +    TCGv t1;
> +    TCGv_i32 tsz = tcg_const_i32(1 << sz);
> +    uint64_t mask = 0;

Should be uint32_t

> +
> +    if (rd == 0) {
> +        /* Treat as NOP. */

Need to free tsz on this path or wait to assign with t0/t1

> +        return;
> +    }
> +    t0 = tcg_temp_new();
> +    t1 = tcg_temp_new();
> +
> +    gen_load_gpr(t0, rt);
> +    gen_load_gpr(t1, rs);
> +
> +    if (sz != 3) {
> +        switch (sz) {
> +        case 0:
> +            mask = 0xFF;
> +            break;
> +        case 1:
> +            mask = 0xFFFF;
> +            break;
> +        case 2:
> +            mask = 0xFFFFFFFF;
> +            break;
> +        }
> +        tcg_gen_andi_tl(t1, t1, mask);
> +    }
> +
> +    if (crc32c) {
> +        gen_helper_crc32c(cpu_gpr[rd], t0, t1, tsz);
> +    } else {
> +        gen_helper_crc32(cpu_gpr[rd], t0, t1, tsz);
> +    }
> +
> +    tcg_temp_free(t0);
> +    tcg_temp_free(t1);
> +    tcg_temp_free_i32(tsz);
> +}
> +
> +static void gen_crc32b(DisasContext *ctx, int rd, int rs, int rt) {
> +    gen_crc32(ctx, rd, rs, rt, 0, 0);
> +}
> +
> +static void gen_crc32h(DisasContext *ctx, int rd, int rs, int rt) {
> +    gen_crc32(ctx, rd, rs, rt, 1, 0);
> +}
> +
> +static void gen_crc32w(DisasContext *ctx, int rd, int rs, int rt) {
> +    gen_crc32(ctx, rd, rs, rt, 2, 0);
> +}
> +
> +static void gen_crc32d(DisasContext *ctx, int rd, int rs, int rt) {
> +    gen_crc32(ctx, rd, rs, rt, 3, 0);
> +}
> +
> +static void gen_crc32cb(DisasContext *ctx, int rd, int rs, int rt) {
> +    gen_crc32(ctx, rd, rs, rt, 0, 1);
> +}
> +
> +static void gen_crc32ch(DisasContext *ctx, int rd, int rs, int rt) {
> +    gen_crc32(ctx, rd, rs, rt, 1, 1);
> +}
> +
> +static void gen_crc32cw(DisasContext *ctx, int rd, int rs, int rt) {
> +    gen_crc32(ctx, rd, rs, rt, 2, 1);
> +}
> +
> +static void gen_crc32cd(DisasContext *ctx, int rd, int rs, int rt) {
> +    gen_crc32(ctx, rd, rs, rt, 3, 1);
> +}
> +
>  static void decode_opc_special3_r6(CPUMIPSState *env, DisasContext *ctx)
> {
>      int rs, rt, rd, sa;
>      uint32_t op1, op2;
>      int16_t imm;
> +    int sz, crc32c;
>
>      rs = (ctx->opcode >> 21) & 0x1f;
>      rt = (ctx->opcode >> 16) & 0x1f;
> @@ -27131,6 +27218,45 @@ static void
> decode_opc_special3_r6(CPUMIPSState *env, DisasContext *ctx)
>
>      op1 = MASK_SPECIAL3(ctx->opcode);
>      switch (op1) {
> +    case OPC_CRC32:
> +        sz = extract32(ctx->opcode, 6, 2);
> +        crc32c = extract32(ctx->opcode, 8, 3);
> +        if (unlikely(!ctx->crcp) ||
> +            unlikely((sz == 3) && (!(ctx->hflags & MIPS_HFLAG_64))) ||
> +            unlikely((crc32c >= 2))) {
> +            generate_exception_end(ctx, EXCP_RI);
> +        }
> +        switch (sz) {
> +        case 0:
> +            if (crc32c) {
> +                gen_crc32cb(ctx, rt, rs, rt);
> +            } else {
> +                gen_crc32b(ctx, rt, rs, rt);
> +            }
> +            break;
> +        case 1:
> +            if (crc32c) {
> +                gen_crc32ch(ctx, rt, rs, rt);
> +            } else {
> +                gen_crc32h(ctx, rt, rs, rt);
> +            }
> +            break;
> +        case 2:
> +            if (crc32c) {
> +                gen_crc32cw(ctx, rt, rs, rt);
> +            } else {
> +                gen_crc32w(ctx, rt, rs, rt);
> +            }
> +            break;
> +        case 3:
> +            if (crc32c) {
> +                gen_crc32cd(ctx, rt, rs, rt);
> +            } else {
> +                gen_crc32d(ctx, rt, rs, rt);
> +            }
> +            break;
> +        }
> +        break;
>      case R6_OPC_PREF:
>          if (rt >= 24) {
>              /* hint codes 24-31 are reserved and signal RI */ @@ -30727,6
> +30853,7 @@ static void mips_tr_init_disas_context(DisasContextBase
> *dcbase, CPUState *cs)
>      ctx->mrp = (env->CP0_Config5 >> CP0C5_MRP) & 1;
>      ctx->nan2008 = (env->active_fpu.fcr31 >> FCR31_NAN2008) & 1;
>      ctx->abs2008 = (env->active_fpu.fcr31 >> FCR31_ABS2008) & 1;
> +    ctx->crcp = (env->CP0_Config5 >> CP0C5_CRCP) & 1;
>      restore_cpu_state(env, ctx);
>  #ifdef CONFIG_USER_ONLY
>          ctx->mem_idx = MIPS_HFLAG_UM;
> --
> 2.7.4
>
>