From 0c1bbedc10e86ea9366b6af8c5520fafa3266b2f Mon Sep 17 00:00:00 2001 From: Stefan Markovic Date: Tue, 23 Oct 2018 11:44:36 +0200 Subject: [PATCH] linux-user: Determine the desired FPU mode from MIPS.abiflags Floating-point mode is calculated from MIPS.abiflags FP ABI value (based on kernel implementation). Illegal combinations are rejected. Reviewed-by: Aleksandar Markovic Signed-off-by: Stefan Markovic --- linux-user/mips/cpu_loop.c | 75 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) diff --git a/linux-user/mips/cpu_loop.c b/linux-user/mips/cpu_loop.c index c9c20cf8b7..97e495747f 100644 --- a/linux-user/mips/cpu_loop.c +++ b/linux-user/mips/cpu_loop.c @@ -740,6 +740,34 @@ void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs) struct image_info *info = ts->info; int i; + struct mode_req { + bool single; + bool soft; + bool fr1; + bool frdefault; + bool fre; + }; + + static const struct mode_req fpu_reqs[] = { + [MIPS_ABI_FP_ANY] = { true, true, true, true, true }, + [MIPS_ABI_FP_DOUBLE] = { false, false, false, true, true }, + [MIPS_ABI_FP_SINGLE] = { true, false, false, false, false }, + [MIPS_ABI_FP_SOFT] = { false, true, false, false, false }, + [MIPS_ABI_FP_OLD_64] = { false, false, false, false, false }, + [MIPS_ABI_FP_XX] = { false, false, true, true, true }, + [MIPS_ABI_FP_64] = { false, false, true, false, false }, + [MIPS_ABI_FP_64A] = { false, false, true, false, true } + }; + + /* + * Mode requirements when .MIPS.abiflags is not present in the ELF. + * Not present means that everything is acceptable except FR1. + */ + static struct mode_req none_req = { true, true, false, true, true }; + + struct mode_req prog_req; + struct mode_req interp_req; + for(i = 0; i < 32; i++) { env->active_tc.gpr[i] = regs->regs[i]; } @@ -747,6 +775,53 @@ void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs) if (regs->cp0_epc & 1) { env->hflags |= MIPS_HFLAG_M16; } + +#ifdef TARGET_ABI_MIPSO32 +# define MAX_FP_ABI MIPS_ABI_FP_64A +#else +# define MAX_FP_ABI MIPS_ABI_FP_SOFT +#endif + if ((info->fp_abi > MAX_FP_ABI && info->fp_abi != MIPS_ABI_FP_UNKNOWN) + || (info->interp_fp_abi > MAX_FP_ABI && + info->interp_fp_abi != MIPS_ABI_FP_UNKNOWN)) { + fprintf(stderr, "qemu: Unexpected FPU mode\n"); + exit(1); + } + + prog_req = (info->fp_abi == MIPS_ABI_FP_UNKNOWN) ? none_req + : fpu_reqs[info->fp_abi]; + interp_req = (info->interp_fp_abi == MIPS_ABI_FP_UNKNOWN) ? none_req + : fpu_reqs[info->interp_fp_abi]; + + prog_req.single &= interp_req.single; + prog_req.soft &= interp_req.soft; + prog_req.fr1 &= interp_req.fr1; + prog_req.frdefault &= interp_req.frdefault; + prog_req.fre &= interp_req.fre; + + bool cpu_has_mips_r2_r6 = env->insn_flags & ISA_MIPS32R2 || + env->insn_flags & ISA_MIPS64R2 || + env->insn_flags & ISA_MIPS32R6 || + env->insn_flags & ISA_MIPS64R6; + + if (prog_req.fre && !prog_req.frdefault && !prog_req.fr1) { + env->CP0_Config5 |= (1 << CP0C5_FRE); + if (env->active_fpu.fcr0 & (1 << FCR0_FREP)) { + env->hflags |= MIPS_HFLAG_FRE; + } + } else if ((prog_req.fr1 && prog_req.frdefault) || + (prog_req.single && !prog_req.frdefault)) { + if ((env->active_fpu.fcr0 & (1 << FCR0_F64) + && cpu_has_mips_r2_r6) || prog_req.fr1) { + env->CP0_Status |= (1 << CP0St_FR); + env->hflags |= MIPS_HFLAG_F64; + } + } else if (!prog_req.fre && !prog_req.frdefault && + !prog_req.fr1 && !prog_req.single && !prog_req.soft) { + fprintf(stderr, "qemu: Can't find a matching FPU mode\n"); + exit(1); + } + if (env->insn_flags & ISA_NANOMIPS32) { return; }