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target/mips: reimplement SC instruction emulation and use cmpxchg

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Completely rewrite conditional stores handling. Use cmpxchg.

This eliminates need for separate implementations of SC instruction
emulation for user and system emulation.

Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Leon Alrae 2019-02-11 16:09:23 +01:00 committed by Aleksandar Markovic
parent c7c7e1e9a5
commit 33a07fa2db
6 changed files with 44 additions and 191 deletions
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73
linux-user/mips/cpu_loop.c
View File

@ -392,70 +392,6 @@ static const uint8_t mips_syscall_args[] = {
# undef MIPS_SYS
# endif /* O32 */
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;
start_exclusive();
mmap_lock();
flags = page_get_flags(page_addr);
if ((flags & PAGE_READ) == 0) {
segv = 1;
} else {
reg = env->llreg & 0x1f;
d = (env->llreg & 0x20) != 0;
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 && val_wp == llnewval_wp) {
env->active_tc.gpr[reg] = 0;
} else {
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;
}
}
}
}
env->lladdr = -1;
if (!segv) {
env->active_tc.PC += 4;
}
mmap_unlock();
end_exclusive();
return segv;
}
/* Break codes */
enum {
BRK_OVERFLOW = 6,
@ -597,15 +533,6 @@ done_syscall:
info.si_code = TARGET_TRAP_BRKPT;
queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
break;
case EXCP_SC:
if (do_store_exclusive(env)) {
info.si_signo = TARGET_SIGSEGV;
info.si_errno = 0;
info.si_code = TARGET_SEGV_MAPERR;
info._sifields._sigfault._addr = env->active_tc.PC;
queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
}
break;
case EXCP_DSPDIS:
info.si_signo = TARGET_SIGILL;
info.si_errno = 0;

4
target/mips/cpu.h
View File

@ -876,10 +876,8 @@ struct CPUMIPSState {
*/
target_ulong lladdr; /* LL virtual address compared against SC */
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;
/*
@ -1156,8 +1154,6 @@ enum {
EXCP_LAST = EXCP_TLBRI,
};
/* Dummy exception for conditional stores. */
#define EXCP_SC 0x100
/*
* This is an internally generated WAKE request line.

6
target/mips/helper.c
View File

@ -1463,10 +1463,8 @@ void QEMU_NORETURN do_raise_exception_err(CPUMIPSState *env,
{
CPUState *cs = CPU(mips_env_get_cpu(env));
if (exception < EXCP_SC) {
qemu_log_mask(CPU_LOG_INT, "%s: %d %d\n",
__func__, exception, error_code);
}
qemu_log_mask(CPU_LOG_INT, "%s: %d %d\n",
__func__, exception, error_code);
cs->exception_index = exception;
env->error_code = error_code;

2
target/mips/helper.h
View File

@ -13,10 +13,8 @@ DEF_HELPER_4(swr, void, env, tl, tl, int)
#ifndef CONFIG_USER_ONLY
DEF_HELPER_3(ll, tl, env, tl, int)
DEF_HELPER_4(sc, tl, env, tl, tl, int)
#ifdef TARGET_MIPS64
DEF_HELPER_3(lld, tl, env, tl, int)
DEF_HELPER_4(scd, tl, env, tl, tl, int)
#endif
#endif

27
target/mips/op_helper.c
View File

@ -380,33 +380,6 @@ HELPER_LD_ATOMIC(ll, lw, 0x3)
HELPER_LD_ATOMIC(lld, ld, 0x7)
#endif
#undef HELPER_LD_ATOMIC
#define HELPER_ST_ATOMIC(name, ld_insn, st_insn, almask) \
target_ulong helper_##name(CPUMIPSState *env, target_ulong arg1, \
target_ulong arg2, int mem_idx) \
{ \
target_long tmp; \
\
if (arg2 & almask) { \
if (!(env->hflags & MIPS_HFLAG_DM)) { \
env->CP0_BadVAddr = arg2; \
} \
do_raise_exception(env, EXCP_AdES, GETPC()); \
} \
if (arg2 == env->lladdr) { \
tmp = do_##ld_insn(env, arg2, mem_idx, GETPC()); \
if (tmp == env->llval) { \
do_##st_insn(env, arg2, arg1, mem_idx, GETPC()); \
return 1; \
} \
} \
return 0; \
}
HELPER_ST_ATOMIC(sc, lw, sw, 0x3)
#ifdef TARGET_MIPS64
HELPER_ST_ATOMIC(scd, ld, sd, 0x7)
#endif
#undef HELPER_ST_ATOMIC
#endif
#ifdef TARGET_WORDS_BIGENDIAN

123
target/mips/translate.c
View File

@ -2450,6 +2450,7 @@ enum {
static TCGv cpu_gpr[32], cpu_PC;
static TCGv cpu_HI[MIPS_DSP_ACC], cpu_LO[MIPS_DSP_ACC];
static TCGv cpu_dspctrl, btarget, bcond;
static TCGv cpu_lladdr, cpu_llval;
static TCGv_i32 hflags;
static TCGv_i32 fpu_fcr0, fpu_fcr31;
static TCGv_i64 fpu_f64[32];
@ -3326,48 +3327,6 @@ OP_LD_ATOMIC(lld,ld64);
#endif
#undef OP_LD_ATOMIC
#ifdef CONFIG_USER_ONLY
#define OP_ST_ATOMIC(insn,fname,ldname,almask) \
static inline void op_st_##insn(TCGv arg1, TCGv arg2, int rt, int mem_idx, \
DisasContext *ctx) \
{ \
TCGv t0 = tcg_temp_new(); \
TCGLabel *l1 = gen_new_label(); \
TCGLabel *l2 = gen_new_label(); \
\
tcg_gen_andi_tl(t0, arg2, almask); \
tcg_gen_brcondi_tl(TCG_COND_EQ, t0, 0, l1); \
tcg_gen_st_tl(arg2, cpu_env, offsetof(CPUMIPSState, CP0_BadVAddr)); \
generate_exception(ctx, EXCP_AdES); \
gen_set_label(l1); \
tcg_gen_ld_tl(t0, cpu_env, offsetof(CPUMIPSState, lladdr)); \
tcg_gen_brcond_tl(TCG_COND_NE, arg2, t0, l2); \
tcg_gen_movi_tl(t0, rt | ((almask << 3) & 0x20)); \
tcg_gen_st_tl(t0, cpu_env, offsetof(CPUMIPSState, llreg)); \
tcg_gen_st_tl(arg1, cpu_env, offsetof(CPUMIPSState, llnewval)); \
generate_exception_end(ctx, EXCP_SC); \
gen_set_label(l2); \
tcg_gen_movi_tl(t0, 0); \
gen_store_gpr(t0, rt); \
tcg_temp_free(t0); \
}
#else
#define OP_ST_ATOMIC(insn,fname,ldname,almask) \
static inline void op_st_##insn(TCGv arg1, TCGv arg2, int rt, int mem_idx, \
DisasContext *ctx) \
{ \
TCGv t0 = tcg_temp_new(); \
gen_helper_1e2i(insn, t0, arg1, arg2, mem_idx); \
gen_store_gpr(t0, rt); \
tcg_temp_free(t0); \
}
#endif
OP_ST_ATOMIC(sc,st32,ld32s,0x3);
#if defined(TARGET_MIPS64)
OP_ST_ATOMIC(scd,st64,ld64,0x7);
#endif
#undef OP_ST_ATOMIC
static void gen_base_offset_addr (DisasContext *ctx, TCGv addr,
int base, int offset)
{
@ -3679,40 +3638,38 @@ static void gen_st (DisasContext *ctx, uint32_t opc, int rt,
/* Store conditional */
static void gen_st_cond (DisasContext *ctx, uint32_t opc, int rt,
int base, int16_t offset)
static void gen_st_cond(DisasContext *ctx, int rt, int base, int offset,
TCGMemOp tcg_mo, bool eva)
{
TCGv t0, t1;
int mem_idx = ctx->mem_idx;
TCGv addr, t0, val;
TCGLabel *l1 = gen_new_label();
TCGLabel *done = gen_new_label();
#ifdef CONFIG_USER_ONLY
t0 = tcg_temp_local_new();
t1 = tcg_temp_local_new();
#else
t0 = tcg_temp_new();
t1 = tcg_temp_new();
#endif
gen_base_offset_addr(ctx, t0, base, offset);
gen_load_gpr(t1, rt);
switch (opc) {
#if defined(TARGET_MIPS64)
case OPC_SCD:
case R6_OPC_SCD:
op_st_scd(t1, t0, rt, mem_idx, ctx);
break;
#endif
case OPC_SCE:
mem_idx = MIPS_HFLAG_UM;
/* fall through */
case OPC_SC:
case R6_OPC_SC:
op_st_sc(t1, t0, rt, mem_idx, ctx);
break;
}
tcg_temp_free(t1);
addr = tcg_temp_new();
/* compare the address against that of the preceeding LL */
gen_base_offset_addr(ctx, addr, base, offset);
tcg_gen_brcond_tl(TCG_COND_EQ, addr, cpu_lladdr, l1);
tcg_temp_free(addr);
tcg_gen_movi_tl(t0, 0);
gen_store_gpr(t0, rt);
tcg_gen_br(done);
gen_set_label(l1);
/* generate cmpxchg */
val = tcg_temp_new();
gen_load_gpr(val, rt);
tcg_gen_atomic_cmpxchg_tl(t0, cpu_lladdr, cpu_llval, val,
eva ? MIPS_HFLAG_UM : ctx->mem_idx, tcg_mo);
tcg_gen_setcond_tl(TCG_COND_EQ, t0, t0, cpu_llval);
gen_store_gpr(t0, rt);
tcg_temp_free(val);
gen_set_label(done);
tcg_temp_free(t0);
}
static void gen_scwp(DisasContext *ctx, uint32_t base, int16_t offset,
uint32_t reg1, uint32_t reg2, bool eva)
{
@ -16864,13 +16821,13 @@ static void decode_micromips32_opc(CPUMIPSState *env, DisasContext *ctx)
gen_st(ctx, mips32_op, rt, rs, offset);
break;
case SC:
gen_st_cond(ctx, OPC_SC, rt, rs, offset);
gen_st_cond(ctx, rt, rs, offset, MO_TESL, false);
break;
#if defined(TARGET_MIPS64)
case SCD:
check_insn(ctx, ISA_MIPS3);
check_mips_64(ctx);
gen_st_cond(ctx, OPC_SCD, rt, rs, offset);
gen_st_cond(ctx, rt, rs, offset, MO_TEQ, false);
break;
#endif
case LD_EVA:
@ -16951,7 +16908,7 @@ static void decode_micromips32_opc(CPUMIPSState *env, DisasContext *ctx)
mips32_op = OPC_SHE;
goto do_st_lr;
case SCE:
gen_st_cond(ctx, OPC_SCE, rt, rs, offset);
gen_st_cond(ctx, rt, rs, offset, MO_TESL, true);
break;
case SWE:
mips32_op = OPC_SWE;
@ -21558,7 +21515,7 @@ static int decode_nanomips_32_48_opc(CPUMIPSState *env, DisasContext *ctx)
case NM_P_SC:
switch (ctx->opcode & 0x03) {
case NM_SC:
gen_st_cond(ctx, OPC_SC, rt, rs, s);
gen_st_cond(ctx, rt, rs, s, MO_TESL, false);
break;
case NM_SCWP:
check_xnp(ctx);
@ -21661,7 +21618,7 @@ static int decode_nanomips_32_48_opc(CPUMIPSState *env, DisasContext *ctx)
check_xnp(ctx);
check_eva(ctx);
check_cp0_enabled(ctx);
gen_st_cond(ctx, OPC_SCE, rt, rs, s);
gen_st_cond(ctx, rt, rs, s, MO_TESL, true);
break;
case NM_SCWPE:
check_xnp(ctx);
@ -26698,7 +26655,7 @@ static void decode_opc_special3_r6(CPUMIPSState *env, DisasContext *ctx)
}
break;
case R6_OPC_SC:
gen_st_cond(ctx, op1, rt, rs, imm);
gen_st_cond(ctx, rt, rs, imm, MO_TESL, false);
break;
case R6_OPC_LL:
gen_ld(ctx, op1, rt, rs, imm);
@ -26725,7 +26682,7 @@ static void decode_opc_special3_r6(CPUMIPSState *env, DisasContext *ctx)
break;
#if defined(TARGET_MIPS64)
case R6_OPC_SCD:
gen_st_cond(ctx, op1, rt, rs, imm);
gen_st_cond(ctx, rt, rs, imm, MO_TEQ, false);
break;
case R6_OPC_LLD:
gen_ld(ctx, op1, rt, rs, imm);
@ -27580,7 +27537,7 @@ static void decode_opc_special3(CPUMIPSState *env, DisasContext *ctx)
return;
case OPC_SCE:
check_cp0_enabled(ctx);
gen_st_cond(ctx, op1, rt, rs, imm);
gen_st_cond(ctx, rt, rs, imm, MO_TESL, true);
return;
case OPC_CACHEE:
check_cp0_enabled(ctx);
@ -29172,8 +29129,8 @@ static void decode_opc(CPUMIPSState *env, DisasContext *ctx)
if (ctx->insn_flags & INSN_R5900) {
check_insn_opc_user_only(ctx, INSN_R5900);
}
gen_st_cond(ctx, op, rt, rs, imm);
break;
gen_st_cond(ctx, rt, rs, imm, MO_TESL, false);
break;
case OPC_CACHE:
check_insn_opc_removed(ctx, ISA_MIPS32R6);
check_cp0_enabled(ctx);
@ -29472,7 +29429,7 @@ static void decode_opc(CPUMIPSState *env, DisasContext *ctx)
check_insn_opc_user_only(ctx, INSN_R5900);
}
check_mips_64(ctx);
gen_st_cond(ctx, op, rt, rs, imm);
gen_st_cond(ctx, rt, rs, imm, MO_TEQ, false);
break;
case OPC_BNVC: /* OPC_BNEZALC, OPC_BNEC, OPC_DADDI */
if (ctx->insn_flags & ISA_MIPS32R6) {
@ -29853,6 +29810,10 @@ void mips_tcg_init(void)
fpu_fcr31 = tcg_global_mem_new_i32(cpu_env,
offsetof(CPUMIPSState, active_fpu.fcr31),
"fcr31");
cpu_lladdr = tcg_global_mem_new(cpu_env, offsetof(CPUMIPSState, lladdr),
"lladdr");
cpu_llval = tcg_global_mem_new(cpu_env, offsetof(CPUMIPSState, llval),
"llval");
#if defined(TARGET_MIPS64)
cpu_mmr[0] = NULL;