From 0b16dcd180bdbe3add9edea42c2374d427882661 Mon Sep 17 00:00:00 2001 From: Aleksandar Rikalo Date: Tue, 7 Aug 2018 12:40:04 +0200 Subject: [PATCH] target/mips: Implement emulation of nanoMIPS LLWP/SCWP pair Implement support for nanoMIPS LLWP/SCWP instructions. Beside adding core functionality of these instructions, this patch adds support for availability control via configuration bit XNP. Reviewed-by: Richard Henderson Reviewed-by: Aleksandar Markovic Signed-off-by: Dimitrije Nikolic Signed-off-by: Aleksandar Markovic Signed-off-by: Stefan Markovic --- linux-user/mips/cpu_loop.c | 25 ++++++++--- target/mips/cpu.h | 2 + target/mips/translate.c | 86 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 108 insertions(+), 5 deletions(-) diff --git a/linux-user/mips/cpu_loop.c b/linux-user/mips/cpu_loop.c index 084ad6a041..1d3dc9e913 100644 --- a/linux-user/mips/cpu_loop.c +++ b/linux-user/mips/cpu_loop.c @@ -397,10 +397,13 @@ static int do_store_exclusive(CPUMIPSState *env) target_ulong addr; target_ulong page_addr; target_ulong val; + uint32_t val_wp = 0; + uint32_t llnewval_wp = 0; int flags; int segv = 0; int reg; int d; + int wp; addr = env->lladdr; page_addr = addr & TARGET_PAGE_MASK; @@ -412,19 +415,31 @@ static int do_store_exclusive(CPUMIPSState *env) } else { reg = env->llreg & 0x1f; d = (env->llreg & 0x20) != 0; - if (d) { - segv = get_user_s64(val, addr); + wp = (env->llreg & 0x40) != 0; + if (!wp) { + if (d) { + segv = get_user_s64(val, addr); + } else { + segv = get_user_s32(val, addr); + } } else { segv = get_user_s32(val, addr); + segv |= get_user_s32(val_wp, addr); + llnewval_wp = env->llnewval_wp; } if (!segv) { - if (val != env->llval) { + if (val != env->llval && val_wp == llnewval_wp) { env->active_tc.gpr[reg] = 0; } else { - if (d) { - segv = put_user_u64(env->llnewval, addr); + if (!wp) { + if (d) { + segv = put_user_u64(env->llnewval, addr); + } else { + segv = put_user_u32(env->llnewval, addr); + } } else { segv = put_user_u32(env->llnewval, addr); + segv |= put_user_u32(env->llnewval_wp, addr + 4); } if (!segv) { env->active_tc.gpr[reg] = 1; diff --git a/target/mips/cpu.h b/target/mips/cpu.h index 009202cf64..28af4d191c 100644 --- a/target/mips/cpu.h +++ b/target/mips/cpu.h @@ -506,6 +506,8 @@ struct CPUMIPSState { uint64_t lladdr; target_ulong llval; target_ulong llnewval; + uint64_t llval_wp; + uint32_t llnewval_wp; target_ulong llreg; uint64_t CP0_LLAddr_rw_bitmask; int CP0_LLAddr_shift; diff --git a/target/mips/translate.c b/target/mips/translate.c index 10475a6c6b..28d9d0c369 100644 --- a/target/mips/translate.c +++ b/target/mips/translate.c @@ -1916,6 +1916,18 @@ static inline void check_mvh(DisasContext *ctx) } #endif +/* + * This code generates a "reserved instruction" exception if the + * Config5 XNP bit is set. + */ +static inline void check_xnp(DisasContext *ctx) +{ + if (unlikely(ctx->CP0_Config5 & (1 << CP0C5_XNP))) { + generate_exception_end(ctx, EXCP_RI); + } +} + + /* Define small wrappers for gen_load_fpr* so that we have a uniform calling interface for 32 and 64-bit FPRs. No sense in changing all callers for gen_load_fpr32 when we need the CTX parameter for @@ -2362,6 +2374,31 @@ static void gen_ld(DisasContext *ctx, uint32_t opc, tcg_temp_free(t0); } +static void gen_llwp(DisasContext *ctx, uint32_t base, int16_t offset, + uint32_t reg1, uint32_t reg2) +{ + TCGv taddr = tcg_temp_new(); + TCGv_i64 tval = tcg_temp_new_i64(); + TCGv tmp1 = tcg_temp_new(); + TCGv tmp2 = tcg_temp_new(); + + gen_base_offset_addr(ctx, taddr, base, offset); + tcg_gen_qemu_ld64(tval, taddr, ctx->mem_idx); +#ifdef TARGET_WORDS_BIGENDIAN + tcg_gen_extr_i64_tl(tmp2, tmp1, tval); +#else + tcg_gen_extr_i64_tl(tmp1, tmp2, tval); +#endif + gen_store_gpr(tmp1, reg1); + tcg_temp_free(tmp1); + gen_store_gpr(tmp2, reg2); + tcg_temp_free(tmp2); + tcg_gen_st_i64(tval, cpu_env, offsetof(CPUMIPSState, llval_wp)); + tcg_temp_free_i64(tval); + tcg_gen_st_tl(taddr, cpu_env, offsetof(CPUMIPSState, lladdr)); + tcg_temp_free(taddr); +} + /* Store */ static void gen_st (DisasContext *ctx, uint32_t opc, int rt, int base, int offset) @@ -2458,6 +2495,51 @@ static void gen_st_cond (DisasContext *ctx, uint32_t opc, int rt, tcg_temp_free(t0); } +static void gen_scwp(DisasContext *ctx, uint32_t base, int16_t offset, + uint32_t reg1, uint32_t reg2) +{ + TCGv taddr = tcg_temp_local_new(); + TCGv lladdr = tcg_temp_local_new(); + TCGv_i64 tval = tcg_temp_new_i64(); + TCGv_i64 llval = tcg_temp_new_i64(); + TCGv_i64 val = tcg_temp_new_i64(); + TCGv tmp1 = tcg_temp_new(); + TCGv tmp2 = tcg_temp_new(); + TCGLabel *lab_fail = gen_new_label(); + TCGLabel *lab_done = gen_new_label(); + + gen_base_offset_addr(ctx, taddr, base, offset); + + tcg_gen_ld_tl(lladdr, cpu_env, offsetof(CPUMIPSState, lladdr)); + tcg_gen_brcond_tl(TCG_COND_NE, taddr, lladdr, lab_fail); + + gen_load_gpr(tmp1, reg1); + gen_load_gpr(tmp2, reg2); + +#ifdef TARGET_WORDS_BIGENDIAN + tcg_gen_concat_tl_i64(tval, tmp2, tmp1); +#else + tcg_gen_concat_tl_i64(tval, tmp1, tmp2); +#endif + + tcg_gen_ld_i64(llval, cpu_env, offsetof(CPUMIPSState, llval_wp)); + tcg_gen_atomic_cmpxchg_i64(val, taddr, llval, tval, + ctx->mem_idx, MO_64); + if (reg1 != 0) { + tcg_gen_movi_tl(cpu_gpr[reg1], 1); + } + tcg_gen_brcond_i64(TCG_COND_EQ, val, llval, lab_done); + + gen_set_label(lab_fail); + + if (reg1 != 0) { + tcg_gen_movi_tl(cpu_gpr[reg1], 0); + } + gen_set_label(lab_done); + tcg_gen_movi_tl(lladdr, -1); + tcg_gen_st_tl(lladdr, cpu_env, offsetof(CPUMIPSState, lladdr)); +} + /* Load and store */ static void gen_flt_ldst (DisasContext *ctx, uint32_t opc, int ft, TCGv t0) @@ -18120,6 +18202,8 @@ static int decode_nanomips_32_48_opc(CPUMIPSState *env, DisasContext *ctx) gen_ld(ctx, OPC_LL, rt, rs, s); break; case NM_LLWP: + check_xnp(ctx); + gen_llwp(ctx, rs, 0, rt, extract32(ctx->opcode, 3, 5)); break; } break; @@ -18129,6 +18213,8 @@ static int decode_nanomips_32_48_opc(CPUMIPSState *env, DisasContext *ctx) gen_st_cond(ctx, OPC_SC, rt, rs, s); break; case NM_SCWP: + check_xnp(ctx); + gen_scwp(ctx, rs, 0, rt, extract32(ctx->opcode, 3, 5)); break; } break;