/* * cp1emu.c: a MIPS coprocessor 1 (fpu) instruction emulator * * MIPS floating point support * Copyright (C) 1994-2000 Algorithmics Ltd. * http://www.algor.co.uk * * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com * Copyright (C) 2000 MIPS Technologies, Inc. * * This program is free software; you can distribute it and/or modify it * under the terms of the GNU General Public License (Version 2) as * published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. * * A complete emulator for MIPS coprocessor 1 instructions. This is * required for #float(switch) or #float(trap), where it catches all * COP1 instructions via the "CoProcessor Unusable" exception. * * More surprisingly it is also required for #float(ieee), to help out * the hardware fpu at the boundaries of the IEEE-754 representation * (denormalised values, infinities, underflow, etc). It is made * quite nasty because emulation of some non-COP1 instructions is * required, e.g. in branch delay slots. * * Note if you know that you won't have an fpu, then you'll get much * better performance by compiling with -msoft-float! */ #include <linux/sched.h> #include <asm/inst.h> #include <asm/bootinfo.h> #include <asm/cpu.h> #include <asm/cpu-features.h> #include <asm/processor.h> #include <asm/ptrace.h> #include <asm/signal.h> #include <asm/mipsregs.h> #include <asm/fpu_emulator.h> #include <asm/uaccess.h> #include <asm/branch.h> #include "ieee754.h" #include "dsemul.h" /* Strap kernel emulator for full MIPS IV emulation */ #ifdef __mips #undef __mips #endif #define __mips 4 /* Function which emulates a floating point instruction. */ static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *, mips_instruction); #if __mips >= 4 && __mips != 32 static int fpux_emu(struct pt_regs *, struct mips_fpu_struct *, mips_instruction); #endif /* Further private data for which no space exists in mips_fpu_struct */ struct mips_fpu_emulator_stats fpuemustats; /* Control registers */ #define FPCREG_RID 0 /* $0 = revision id */ #define FPCREG_CSR 31 /* $31 = csr */ /* Convert Mips rounding mode (0..3) to IEEE library modes. */ static const unsigned char ieee_rm[4] = { [FPU_CSR_RN] = IEEE754_RN, [FPU_CSR_RZ] = IEEE754_RZ, [FPU_CSR_RU] = IEEE754_RU, [FPU_CSR_RD] = IEEE754_RD, }; /* Convert IEEE library modes to Mips rounding mode (0..3). */ static const unsigned char mips_rm[4] = { [IEEE754_RN] = FPU_CSR_RN, [IEEE754_RZ] = FPU_CSR_RZ, [IEEE754_RD] = FPU_CSR_RD, [IEEE754_RU] = FPU_CSR_RU, }; #if __mips >= 4 /* convert condition code register number to csr bit */ static const unsigned int fpucondbit[8] = { FPU_CSR_COND0, FPU_CSR_COND1, FPU_CSR_COND2, FPU_CSR_COND3, FPU_CSR_COND4, FPU_CSR_COND5, FPU_CSR_COND6, FPU_CSR_COND7 }; #endif /* * Redundant with logic already in kernel/branch.c, * embedded in compute_return_epc. At some point, * a single subroutine should be used across both * modules. */ static int isBranchInstr(mips_instruction * i) { switch (MIPSInst_OPCODE(*i)) { case spec_op: switch (MIPSInst_FUNC(*i)) { case jalr_op: case jr_op: return 1; } break; case bcond_op: switch (MIPSInst_RT(*i)) { case bltz_op: case bgez_op: case bltzl_op: case bgezl_op: case bltzal_op: case bgezal_op: case bltzall_op: case bgezall_op: return 1; } break; case j_op: case jal_op: case jalx_op: case beq_op: case bne_op: case blez_op: case bgtz_op: case beql_op: case bnel_op: case blezl_op: case bgtzl_op: return 1; case cop0_op: case cop1_op: case cop2_op: case cop1x_op: if (MIPSInst_RS(*i) == bc_op) return 1; break; } return 0; } /* * In the Linux kernel, we support selection of FPR format on the * basis of the Status.FR bit. This does imply that, if a full 32 * FPRs are desired, there needs to be a flip-flop that can be written * to one at that bit position. In any case, O32 MIPS ABI uses * only the even FPRs (Status.FR = 0). */ #define CP0_STATUS_FR_SUPPORT #ifdef CP0_STATUS_FR_SUPPORT #define FR_BIT ST0_FR #else #define FR_BIT 0 #endif #define SIFROMREG(si,x) ((si) = \ (xcp->cp0_status & FR_BIT) || !(x & 1) ? \ (int)ctx->fpr[x] : \ (int)(ctx->fpr[x & ~1] >> 32 )) #define SITOREG(si,x) (ctx->fpr[x & ~((xcp->cp0_status & FR_BIT) == 0)] = \ (xcp->cp0_status & FR_BIT) || !(x & 1) ? \ ctx->fpr[x & ~1] >> 32 << 32 | (u32)(si) : \ ctx->fpr[x & ~1] << 32 >> 32 | (u64)(si) << 32) #define DIFROMREG(di,x) ((di) = \ ctx->fpr[x & ~((xcp->cp0_status & FR_BIT) == 0)]) #define DITOREG(di,x) (ctx->fpr[x & ~((xcp->cp0_status & FR_BIT) == 0)] \ = (di)) #define SPFROMREG(sp,x) SIFROMREG((sp).bits,x) #define SPTOREG(sp,x) SITOREG((sp).bits,x) #define DPFROMREG(dp,x) DIFROMREG((dp).bits,x) #define DPTOREG(dp,x) DITOREG((dp).bits,x) /* * Emulate the single floating point instruction pointed at by EPC. * Two instructions if the instruction is in a branch delay slot. */ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx) { mips_instruction ir; void * emulpc, *contpc; unsigned int cond; if (get_user(ir, (mips_instruction __user *) xcp->cp0_epc)) { fpuemustats.errors++; return SIGBUS; } /* XXX NEC Vr54xx bug workaround */ if ((xcp->cp0_cause & CAUSEF_BD) && !isBranchInstr(&ir)) xcp->cp0_cause &= ~CAUSEF_BD; if (xcp->cp0_cause & CAUSEF_BD) { /* * The instruction to be emulated is in a branch delay slot * which means that we have to emulate the branch instruction * BEFORE we do the cop1 instruction. * * This branch could be a COP1 branch, but in that case we * would have had a trap for that instruction, and would not * come through this route. * * Linux MIPS branch emulator operates on context, updating the * cp0_epc. */ emulpc = (void *) (xcp->cp0_epc + 4); /* Snapshot emulation target */ if (__compute_return_epc(xcp)) { #ifdef CP1DBG printk("failed to emulate branch at %p\n", (void *) (xcp->cp0_epc)); #endif return SIGILL; } if (get_user(ir, (mips_instruction __user *) emulpc)) { fpuemustats.errors++; return SIGBUS; } /* __compute_return_epc() will have updated cp0_epc */ contpc = (void *) xcp->cp0_epc; /* In order not to confuse ptrace() et al, tweak context */ xcp->cp0_epc = (unsigned long) emulpc - 4; } else { emulpc = (void *) xcp->cp0_epc; contpc = (void *) (xcp->cp0_epc + 4); } emul: fpuemustats.emulated++; switch (MIPSInst_OPCODE(ir)) { case ldc1_op:{ u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); u64 val; fpuemustats.loads++; if (get_user(val, va)) { fpuemustats.errors++; return SIGBUS; } DITOREG(val, MIPSInst_RT(ir)); break; } case sdc1_op:{ u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); u64 val; fpuemustats.stores++; DIFROMREG(val, MIPSInst_RT(ir)); if (put_user(val, va)) { fpuemustats.errors++; return SIGBUS; } break; } case lwc1_op:{ u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); u32 val; fpuemustats.loads++; if (get_user(val, va)) { fpuemustats.errors++; return SIGBUS; } SITOREG(val, MIPSInst_RT(ir)); break; } case swc1_op:{ u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); u32 val; fpuemustats.stores++; SIFROMREG(val, MIPSInst_RT(ir)); if (put_user(val, va)) { fpuemustats.errors++; return SIGBUS; } break; } case cop1_op: switch (MIPSInst_RS(ir)) { #if defined(__mips64) case dmfc_op: /* copregister fs -> gpr[rt] */ if (MIPSInst_RT(ir) != 0) { DIFROMREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); } break; case dmtc_op: /* copregister fs <- rt */ DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); break; #endif case mfc_op: /* copregister rd -> gpr[rt] */ if (MIPSInst_RT(ir) != 0) { SIFROMREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); } break; case mtc_op: /* copregister rd <- rt */ SITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); break; case cfc_op:{ /* cop control register rd -> gpr[rt] */ u32 value; if (ir == CP1UNDEF) { return do_dsemulret(xcp); } if (MIPSInst_RD(ir) == FPCREG_CSR) { value = ctx->fcr31; value = (value & ~0x3) | mips_rm[value & 0x3]; #ifdef CSRTRACE printk("%p gpr[%d]<-csr=%08x\n", (void *) (xcp->cp0_epc), MIPSInst_RT(ir), value); #endif } else if (MIPSInst_RD(ir) == FPCREG_RID) value = 0; else value = 0; if (MIPSInst_RT(ir)) xcp->regs[MIPSInst_RT(ir)] = value; break; } case ctc_op:{ /* copregister rd <- rt */ u32 value; if (MIPSInst_RT(ir) == 0) value = 0; else value = xcp->regs[MIPSInst_RT(ir)]; /* we only have one writable control reg */ if (MIPSInst_RD(ir) == FPCREG_CSR) { #ifdef CSRTRACE printk("%p gpr[%d]->csr=%08x\n", (void *) (xcp->cp0_epc), MIPSInst_RT(ir), value); #endif value &= (FPU_CSR_FLUSH | FPU_CSR_ALL_E | FPU_CSR_ALL_S | 0x03); ctx->fcr31 &= ~(FPU_CSR_FLUSH | FPU_CSR_ALL_E | FPU_CSR_ALL_S | 0x03); /* convert to ieee library modes */ ctx->fcr31 |= (value & ~0x3) | ieee_rm[value & 0x3]; } if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { return SIGFPE; } break; } case bc_op:{ int likely = 0; if (xcp->cp0_cause & CAUSEF_BD) return SIGILL; #if __mips >= 4 cond = ctx->fcr31 & fpucondbit[MIPSInst_RT(ir) >> 2]; #else cond = ctx->fcr31 & FPU_CSR_COND; #endif switch (MIPSInst_RT(ir) & 3) { case bcfl_op: likely = 1; case bcf_op: cond = !cond; break; case bctl_op: likely = 1; case bct_op: break; default: /* thats an illegal instruction */ return SIGILL; } xcp->cp0_cause |= CAUSEF_BD; if (cond) { /* branch taken: emulate dslot * instruction */ xcp->cp0_epc += 4; contpc = (void *) (xcp->cp0_epc + (MIPSInst_SIMM(ir) << 2)); if (get_user(ir, (mips_instruction __user *) xcp->cp0_epc)) { fpuemustats.errors++; return SIGBUS; } switch (MIPSInst_OPCODE(ir)) { case lwc1_op: case swc1_op: #if (__mips >= 2 || defined(__mips64)) case ldc1_op: case sdc1_op: #endif case cop1_op: #if __mips >= 4 && __mips != 32 case cop1x_op: #endif /* its one of ours */ goto emul; #if __mips >= 4 case spec_op: if (MIPSInst_FUNC(ir) == movc_op) goto emul; break; #endif } /* * Single step the non-cp1 * instruction in the dslot */ return mips_dsemul(xcp, ir, (unsigned long) contpc); } else { /* branch not taken */ if (likely) { /* * branch likely nullifies * dslot if not taken */ xcp->cp0_epc += 4; contpc += 4; /* * else continue & execute * dslot as normal insn */ } } break; } default: if (!(MIPSInst_RS(ir) & 0x10)) return SIGILL; { int sig; /* a real fpu computation instruction */ if ((sig = fpu_emu(xcp, ctx, ir))) return sig; } } break; #if __mips >= 4 && __mips != 32 case cop1x_op:{ int sig; if ((sig = fpux_emu(xcp, ctx, ir))) return sig; break; } #endif #if __mips >= 4 case spec_op: if (MIPSInst_FUNC(ir) != movc_op) return SIGILL; cond = fpucondbit[MIPSInst_RT(ir) >> 2]; if (((ctx->fcr31 & cond) != 0) == ((MIPSInst_RT(ir) & 1) != 0)) xcp->regs[MIPSInst_RD(ir)] = xcp->regs[MIPSInst_RS(ir)]; break; #endif default: return SIGILL; } /* we did it !! */ xcp->cp0_epc = (unsigned long) contpc; xcp->cp0_cause &= ~CAUSEF_BD; return 0; } /* * Conversion table from MIPS compare ops 48-63 * cond = ieee754dp_cmp(x,y,IEEE754_UN,sig); */ static const unsigned char cmptab[8] = { 0, /* cmp_0 (sig) cmp_sf */ IEEE754_CUN, /* cmp_un (sig) cmp_ngle */ IEEE754_CEQ, /* cmp_eq (sig) cmp_seq */ IEEE754_CEQ | IEEE754_CUN, /* cmp_ueq (sig) cmp_ngl */ IEEE754_CLT, /* cmp_olt (sig) cmp_lt */ IEEE754_CLT | IEEE754_CUN, /* cmp_ult (sig) cmp_nge */ IEEE754_CLT | IEEE754_CEQ, /* cmp_ole (sig) cmp_le */ IEEE754_CLT | IEEE754_CEQ | IEEE754_CUN, /* cmp_ule (sig) cmp_ngt */ }; #if __mips >= 4 && __mips != 32 /* * Additional MIPS4 instructions */ #define DEF3OP(name, p, f1, f2, f3) \ static ieee754##p fpemu_##p##_##name (ieee754##p r, ieee754##p s, \ ieee754##p t) \ { \ struct _ieee754_csr ieee754_csr_save; \ s = f1 (s, t); \ ieee754_csr_save = ieee754_csr; \ s = f2 (s, r); \ ieee754_csr_save.cx |= ieee754_csr.cx; \ ieee754_csr_save.sx |= ieee754_csr.sx; \ s = f3 (s); \ ieee754_csr.cx |= ieee754_csr_save.cx; \ ieee754_csr.sx |= ieee754_csr_save.sx; \ return s; \ } static ieee754dp fpemu_dp_recip(ieee754dp d) { return ieee754dp_div(ieee754dp_one(0), d); } static ieee754dp fpemu_dp_rsqrt(ieee754dp d) { return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d)); } static ieee754sp fpemu_sp_recip(ieee754sp s) { return ieee754sp_div(ieee754sp_one(0), s); } static ieee754sp fpemu_sp_rsqrt(ieee754sp s) { return ieee754sp_div(ieee754sp_one(0), ieee754sp_sqrt(s)); } DEF3OP(madd, sp, ieee754sp_mul, ieee754sp_add,); DEF3OP(msub, sp, ieee754sp_mul, ieee754sp_sub,); DEF3OP(nmadd, sp, ieee754sp_mul, ieee754sp_add, ieee754sp_neg); DEF3OP(nmsub, sp, ieee754sp_mul, ieee754sp_sub, ieee754sp_neg); DEF3OP(madd, dp, ieee754dp_mul, ieee754dp_add,); DEF3OP(msub, dp, ieee754dp_mul, ieee754dp_sub,); DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg); DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg); static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, mips_instruction ir) { unsigned rcsr = 0; /* resulting csr */ fpuemustats.cp1xops++; switch (MIPSInst_FMA_FFMT(ir)) { case s_fmt:{ /* 0 */ ieee754sp(*handler) (ieee754sp, ieee754sp, ieee754sp); ieee754sp fd, fr, fs, ft; u32 __user *va; u32 val; switch (MIPSInst_FUNC(ir)) { case lwxc1_op: va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + xcp->regs[MIPSInst_FT(ir)]); fpuemustats.loads++; if (get_user(val, va)) { fpuemustats.errors++; return SIGBUS; } SITOREG(val, MIPSInst_FD(ir)); break; case swxc1_op: va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + xcp->regs[MIPSInst_FT(ir)]); fpuemustats.stores++; SIFROMREG(val, MIPSInst_FS(ir)); if (put_user(val, va)) { fpuemustats.errors++; return SIGBUS; } break; case madd_s_op: handler = fpemu_sp_madd; goto scoptop; case msub_s_op: handler = fpemu_sp_msub; goto scoptop; case nmadd_s_op: handler = fpemu_sp_nmadd; goto scoptop; case nmsub_s_op: handler = fpemu_sp_nmsub; goto scoptop; scoptop: SPFROMREG(fr, MIPSInst_FR(ir)); SPFROMREG(fs, MIPSInst_FS(ir)); SPFROMREG(ft, MIPSInst_FT(ir)); fd = (*handler) (fr, fs, ft); SPTOREG(fd, MIPSInst_FD(ir)); copcsr: if (ieee754_cxtest(IEEE754_INEXACT)) rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S; if (ieee754_cxtest(IEEE754_UNDERFLOW)) rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S; if (ieee754_cxtest(IEEE754_OVERFLOW)) rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S; if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S; ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr; if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { /*printk ("SIGFPE: fpu csr = %08x\n", ctx->fcr31); */ return SIGFPE; } break; default: return SIGILL; } break; } case d_fmt:{ /* 1 */ ieee754dp(*handler) (ieee754dp, ieee754dp, ieee754dp); ieee754dp fd, fr, fs, ft; u64 __user *va; u64 val; switch (MIPSInst_FUNC(ir)) { case ldxc1_op: va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + xcp->regs[MIPSInst_FT(ir)]); fpuemustats.loads++; if (get_user(val, va)) { fpuemustats.errors++; return SIGBUS; } DITOREG(val, MIPSInst_FD(ir)); break; case sdxc1_op: va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + xcp->regs[MIPSInst_FT(ir)]); fpuemustats.stores++; DIFROMREG(val, MIPSInst_FS(ir)); if (put_user(val, va)) { fpuemustats.errors++; return SIGBUS; } break; case madd_d_op: handler = fpemu_dp_madd; goto dcoptop; case msub_d_op: handler = fpemu_dp_msub; goto dcoptop; case nmadd_d_op: handler = fpemu_dp_nmadd; goto dcoptop; case nmsub_d_op: handler = fpemu_dp_nmsub; goto dcoptop; dcoptop: DPFROMREG(fr, MIPSInst_FR(ir)); DPFROMREG(fs, MIPSInst_FS(ir)); DPFROMREG(ft, MIPSInst_FT(ir)); fd = (*handler) (fr, fs, ft); DPTOREG(fd, MIPSInst_FD(ir)); goto copcsr; default: return SIGILL; } break; } case 0x7: /* 7 */ if (MIPSInst_FUNC(ir) != pfetch_op) { return SIGILL; } /* ignore prefx operation */ break; default: return SIGILL; } return 0; } #endif /* * Emulate a single COP1 arithmetic instruction. */ static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, mips_instruction ir) { int rfmt; /* resulting format */ unsigned rcsr = 0; /* resulting csr */ unsigned cond; union { ieee754dp d; ieee754sp s; int w; #ifdef __mips64 s64 l; #endif } rv; /* resulting value */ fpuemustats.cp1ops++; switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) { case s_fmt:{ /* 0 */ union { ieee754sp(*b) (ieee754sp, ieee754sp); ieee754sp(*u) (ieee754sp); } handler; switch (MIPSInst_FUNC(ir)) { /* binary ops */ case fadd_op: handler.b = ieee754sp_add; goto scopbop; case fsub_op: handler.b = ieee754sp_sub; goto scopbop; case fmul_op: handler.b = ieee754sp_mul; goto scopbop; case fdiv_op: handler.b = ieee754sp_div; goto scopbop; /* unary ops */ #if __mips >= 2 || defined(__mips64) case fsqrt_op: handler.u = ieee754sp_sqrt; goto scopuop; #endif #if __mips >= 4 && __mips != 32 case frsqrt_op: handler.u = fpemu_sp_rsqrt; goto scopuop; case frecip_op: handler.u = fpemu_sp_recip; goto scopuop; #endif #if __mips >= 4 case fmovc_op: cond = fpucondbit[MIPSInst_FT(ir) >> 2]; if (((ctx->fcr31 & cond) != 0) != ((MIPSInst_FT(ir) & 1) != 0)) return 0; SPFROMREG(rv.s, MIPSInst_FS(ir)); break; case fmovz_op: if (xcp->regs[MIPSInst_FT(ir)] != 0) return 0; SPFROMREG(rv.s, MIPSInst_FS(ir)); break; case fmovn_op: if (xcp->regs[MIPSInst_FT(ir)] == 0) return 0; SPFROMREG(rv.s, MIPSInst_FS(ir)); break; #endif case fabs_op: handler.u = ieee754sp_abs; goto scopuop; case fneg_op: handler.u = ieee754sp_neg; goto scopuop; case fmov_op: /* an easy one */ SPFROMREG(rv.s, MIPSInst_FS(ir)); goto copcsr; /* binary op on handler */ scopbop: { ieee754sp fs, ft; SPFROMREG(fs, MIPSInst_FS(ir)); SPFROMREG(ft, MIPSInst_FT(ir)); rv.s = (*handler.b) (fs, ft); goto copcsr; } scopuop: { ieee754sp fs; SPFROMREG(fs, MIPSInst_FS(ir)); rv.s = (*handler.u) (fs); goto copcsr; } copcsr: if (ieee754_cxtest(IEEE754_INEXACT)) rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S; if (ieee754_cxtest(IEEE754_UNDERFLOW)) rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S; if (ieee754_cxtest(IEEE754_OVERFLOW)) rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S; if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S; if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S; break; /* unary conv ops */ case fcvts_op: return SIGILL; /* not defined */ case fcvtd_op:{ ieee754sp fs; SPFROMREG(fs, MIPSInst_FS(ir)); rv.d = ieee754dp_fsp(fs); rfmt = d_fmt; goto copcsr; } case fcvtw_op:{ ieee754sp fs; SPFROMREG(fs, MIPSInst_FS(ir)); rv.w = ieee754sp_tint(fs); rfmt = w_fmt; goto copcsr; } #if __mips >= 2 || defined(__mips64) case fround_op: case ftrunc_op: case fceil_op: case ffloor_op:{ unsigned int oldrm = ieee754_csr.rm; ieee754sp fs; SPFROMREG(fs, MIPSInst_FS(ir)); ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3]; rv.w = ieee754sp_tint(fs); ieee754_csr.rm = oldrm; rfmt = w_fmt; goto copcsr; } #endif /* __mips >= 2 */ #if defined(__mips64) case fcvtl_op:{ ieee754sp fs; SPFROMREG(fs, MIPSInst_FS(ir)); rv.l = ieee754sp_tlong(fs); rfmt = l_fmt; goto copcsr; } case froundl_op: case ftruncl_op: case fceill_op: case ffloorl_op:{ unsigned int oldrm = ieee754_csr.rm; ieee754sp fs; SPFROMREG(fs, MIPSInst_FS(ir)); ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3]; rv.l = ieee754sp_tlong(fs); ieee754_csr.rm = oldrm; rfmt = l_fmt; goto copcsr; } #endif /* defined(__mips64) */ default: if (MIPSInst_FUNC(ir) >= fcmp_op) { unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op; ieee754sp fs, ft; SPFROMREG(fs, MIPSInst_FS(ir)); SPFROMREG(ft, MIPSInst_FT(ir)); rv.w = ieee754sp_cmp(fs, ft, cmptab[cmpop & 0x7], cmpop & 0x8); rfmt = -1; if ((cmpop & 0x8) && ieee754_cxtest (IEEE754_INVALID_OPERATION)) rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; else goto copcsr; } else { return SIGILL; } break; } break; } case d_fmt:{ union { ieee754dp(*b) (ieee754dp, ieee754dp); ieee754dp(*u) (ieee754dp); } handler; switch (MIPSInst_FUNC(ir)) { /* binary ops */ case fadd_op: handler.b = ieee754dp_add; goto dcopbop; case fsub_op: handler.b = ieee754dp_sub; goto dcopbop; case fmul_op: handler.b = ieee754dp_mul; goto dcopbop; case fdiv_op: handler.b = ieee754dp_div; goto dcopbop; /* unary ops */ #if __mips >= 2 || defined(__mips64) case fsqrt_op: handler.u = ieee754dp_sqrt; goto dcopuop; #endif #if __mips >= 4 && __mips != 32 case frsqrt_op: handler.u = fpemu_dp_rsqrt; goto dcopuop; case frecip_op: handler.u = fpemu_dp_recip; goto dcopuop; #endif #if __mips >= 4 case fmovc_op: cond = fpucondbit[MIPSInst_FT(ir) >> 2]; if (((ctx->fcr31 & cond) != 0) != ((MIPSInst_FT(ir) & 1) != 0)) return 0; DPFROMREG(rv.d, MIPSInst_FS(ir)); break; case fmovz_op: if (xcp->regs[MIPSInst_FT(ir)] != 0) return 0; DPFROMREG(rv.d, MIPSInst_FS(ir)); break; case fmovn_op: if (xcp->regs[MIPSInst_FT(ir)] == 0) return 0; DPFROMREG(rv.d, MIPSInst_FS(ir)); break; #endif case fabs_op: handler.u = ieee754dp_abs; goto dcopuop; case fneg_op: handler.u = ieee754dp_neg; goto dcopuop; case fmov_op: /* an easy one */ DPFROMREG(rv.d, MIPSInst_FS(ir)); goto copcsr; /* binary op on handler */ dcopbop:{ ieee754dp fs, ft; DPFROMREG(fs, MIPSInst_FS(ir)); DPFROMREG(ft, MIPSInst_FT(ir)); rv.d = (*handler.b) (fs, ft); goto copcsr; } dcopuop:{ ieee754dp fs; DPFROMREG(fs, MIPSInst_FS(ir)); rv.d = (*handler.u) (fs); goto copcsr; } /* unary conv ops */ case fcvts_op:{ ieee754dp fs; DPFROMREG(fs, MIPSInst_FS(ir)); rv.s = ieee754sp_fdp(fs); rfmt = s_fmt; goto copcsr; } case fcvtd_op: return SIGILL; /* not defined */ case fcvtw_op:{ ieee754dp fs; DPFROMREG(fs, MIPSInst_FS(ir)); rv.w = ieee754dp_tint(fs); /* wrong */ rfmt = w_fmt; goto copcsr; } #if __mips >= 2 || defined(__mips64) case fround_op: case ftrunc_op: case fceil_op: case ffloor_op:{ unsigned int oldrm = ieee754_csr.rm; ieee754dp fs; DPFROMREG(fs, MIPSInst_FS(ir)); ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3]; rv.w = ieee754dp_tint(fs); ieee754_csr.rm = oldrm; rfmt = w_fmt; goto copcsr; } #endif #if defined(__mips64) case fcvtl_op:{ ieee754dp fs; DPFROMREG(fs, MIPSInst_FS(ir)); rv.l = ieee754dp_tlong(fs); rfmt = l_fmt; goto copcsr; } case froundl_op: case ftruncl_op: case fceill_op: case ffloorl_op:{ unsigned int oldrm = ieee754_csr.rm; ieee754dp fs; DPFROMREG(fs, MIPSInst_FS(ir)); ieee754_csr.rm = ieee_rm[MIPSInst_FUNC(ir) & 0x3]; rv.l = ieee754dp_tlong(fs); ieee754_csr.rm = oldrm; rfmt = l_fmt; goto copcsr; } #endif /* __mips >= 3 */ default: if (MIPSInst_FUNC(ir) >= fcmp_op) { unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op; ieee754dp fs, ft; DPFROMREG(fs, MIPSInst_FS(ir)); DPFROMREG(ft, MIPSInst_FT(ir)); rv.w = ieee754dp_cmp(fs, ft, cmptab[cmpop & 0x7], cmpop & 0x8); rfmt = -1; if ((cmpop & 0x8) && ieee754_cxtest (IEEE754_INVALID_OPERATION)) rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; else goto copcsr; } else { return SIGILL; } break; } break; } case w_fmt:{ ieee754sp fs; switch (MIPSInst_FUNC(ir)) { case fcvts_op: /* convert word to single precision real */ SPFROMREG(fs, MIPSInst_FS(ir)); rv.s = ieee754sp_fint(fs.bits); rfmt = s_fmt; goto copcsr; case fcvtd_op: /* convert word to double precision real */ SPFROMREG(fs, MIPSInst_FS(ir)); rv.d = ieee754dp_fint(fs.bits); rfmt = d_fmt; goto copcsr; default: return SIGILL; } break; } #if defined(__mips64) case l_fmt:{ switch (MIPSInst_FUNC(ir)) { case fcvts_op: /* convert long to single precision real */ rv.s = ieee754sp_flong(ctx->fpr[MIPSInst_FS(ir)]); rfmt = s_fmt; goto copcsr; case fcvtd_op: /* convert long to double precision real */ rv.d = ieee754dp_flong(ctx->fpr[MIPSInst_FS(ir)]); rfmt = d_fmt; goto copcsr; default: return SIGILL; } break; } #endif default: return SIGILL; } /* * Update the fpu CSR register for this operation. * If an exception is required, generate a tidy SIGFPE exception, * without updating the result register. * Note: cause exception bits do not accumulate, they are rewritten * for each op; only the flag/sticky bits accumulate. */ ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr; if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { /*printk ("SIGFPE: fpu csr = %08x\n",ctx->fcr31); */ return SIGFPE; } /* * Now we can safely write the result back to the register file. */ switch (rfmt) { case -1:{ #if __mips >= 4 cond = fpucondbit[MIPSInst_FD(ir) >> 2]; #else cond = FPU_CSR_COND; #endif if (rv.w) ctx->fcr31 |= cond; else ctx->fcr31 &= ~cond; break; } case d_fmt: DPTOREG(rv.d, MIPSInst_FD(ir)); break; case s_fmt: SPTOREG(rv.s, MIPSInst_FD(ir)); break; case w_fmt: SITOREG(rv.w, MIPSInst_FD(ir)); break; #if defined(__mips64) case l_fmt: DITOREG(rv.l, MIPSInst_FD(ir)); break; #endif default: return SIGILL; } return 0; } int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx) { unsigned long oldepc, prevepc; mips_instruction insn; int sig = 0; oldepc = xcp->cp0_epc; do { prevepc = xcp->cp0_epc; if (get_user(insn, (mips_instruction __user *) xcp->cp0_epc)) { fpuemustats.errors++; return SIGBUS; } if (insn == 0) xcp->cp0_epc += 4; /* skip nops */ else { /* * The 'ieee754_csr' is an alias of * ctx->fcr31. No need to copy ctx->fcr31 to * ieee754_csr. But ieee754_csr.rm is ieee * library modes. (not mips rounding mode) */ /* convert to ieee library modes */ ieee754_csr.rm = ieee_rm[ieee754_csr.rm]; sig = cop1Emulate(xcp, ctx); /* revert to mips rounding mode */ ieee754_csr.rm = mips_rm[ieee754_csr.rm]; } if (cpu_has_fpu) break; if (sig) break; cond_resched(); } while (xcp->cp0_epc > prevepc); /* SIGILL indicates a non-fpu instruction */ if (sig == SIGILL && xcp->cp0_epc != oldepc) /* but if epc has advanced, then ignore it */ sig = 0; return sig; }