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target/mips: Implement emulation of nanoMIPS LLWP/SCWP pair

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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 <richard.henderson@linaro.org>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Dimitrije Nikolic <dnikolic@wavecomp.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Stefan Markovic <smarkovic@wavecomp.com>
This commit is contained in:
Aleksandar Rikalo 2018-08-07 12:40:04 +02:00 committed by Aleksandar Markovic
parent ab77fc611b
commit 0b16dcd180
3 changed files with 108 additions and 5 deletions
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25
linux-user/mips/cpu_loop.c
View File

@ -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;

2
target/mips/cpu.h
View File

@ -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;

86
target/mips/translate.c
View File

@ -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;