/* * cp1emu.c: a MIPS coprocessor 1 (FPU) instruction emulator * * MIPS floating point support * Copyright (C) 1994-2000 Algorithmics Ltd. * * 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., * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ieee754.h" /* Function which emulates a floating point instruction. */ static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *, mips_instruction); static int fpux_emu(struct pt_regs *, struct mips_fpu_struct *, mips_instruction, void *__user *); /* Control registers */ #define FPCREG_RID 0 /* $0 = revision id */ #define FPCREG_FCCR 25 /* $25 = fccr */ #define FPCREG_FEXR 26 /* $26 = fexr */ #define FPCREG_FENR 28 /* $28 = fenr */ #define FPCREG_CSR 31 /* $31 = csr */ /* convert condition code register number to csr bit */ const unsigned int fpucondbit[8] = { FPU_CSR_COND, FPU_CSR_COND1, FPU_CSR_COND2, FPU_CSR_COND3, FPU_CSR_COND4, FPU_CSR_COND5, FPU_CSR_COND6, FPU_CSR_COND7 }; /* (microMIPS) Convert certain microMIPS instructions to MIPS32 format. */ static const int sd_format[] = {16, 17, 0, 0, 0, 0, 0, 0}; static const int sdps_format[] = {16, 17, 22, 0, 0, 0, 0, 0}; static const int dwl_format[] = {17, 20, 21, 0, 0, 0, 0, 0}; static const int swl_format[] = {16, 20, 21, 0, 0, 0, 0, 0}; /* * This functions translates a 32-bit microMIPS instruction * into a 32-bit MIPS32 instruction. Returns 0 on success * and SIGILL otherwise. */ static int microMIPS32_to_MIPS32(union mips_instruction *insn_ptr) { union mips_instruction insn = *insn_ptr; union mips_instruction mips32_insn = insn; int func, fmt, op; switch (insn.mm_i_format.opcode) { case mm_ldc132_op: mips32_insn.mm_i_format.opcode = ldc1_op; mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; break; case mm_lwc132_op: mips32_insn.mm_i_format.opcode = lwc1_op; mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; break; case mm_sdc132_op: mips32_insn.mm_i_format.opcode = sdc1_op; mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; break; case mm_swc132_op: mips32_insn.mm_i_format.opcode = swc1_op; mips32_insn.mm_i_format.rt = insn.mm_i_format.rs; mips32_insn.mm_i_format.rs = insn.mm_i_format.rt; break; case mm_pool32i_op: /* NOTE: offset is << by 1 if in microMIPS mode. */ if ((insn.mm_i_format.rt == mm_bc1f_op) || (insn.mm_i_format.rt == mm_bc1t_op)) { mips32_insn.fb_format.opcode = cop1_op; mips32_insn.fb_format.bc = bc_op; mips32_insn.fb_format.flag = (insn.mm_i_format.rt == mm_bc1t_op) ? 1 : 0; } else return SIGILL; break; case mm_pool32f_op: switch (insn.mm_fp0_format.func) { case mm_32f_01_op: case mm_32f_11_op: case mm_32f_02_op: case mm_32f_12_op: case mm_32f_41_op: case mm_32f_51_op: case mm_32f_42_op: case mm_32f_52_op: op = insn.mm_fp0_format.func; if (op == mm_32f_01_op) func = madd_s_op; else if (op == mm_32f_11_op) func = madd_d_op; else if (op == mm_32f_02_op) func = nmadd_s_op; else if (op == mm_32f_12_op) func = nmadd_d_op; else if (op == mm_32f_41_op) func = msub_s_op; else if (op == mm_32f_51_op) func = msub_d_op; else if (op == mm_32f_42_op) func = nmsub_s_op; else func = nmsub_d_op; mips32_insn.fp6_format.opcode = cop1x_op; mips32_insn.fp6_format.fr = insn.mm_fp6_format.fr; mips32_insn.fp6_format.ft = insn.mm_fp6_format.ft; mips32_insn.fp6_format.fs = insn.mm_fp6_format.fs; mips32_insn.fp6_format.fd = insn.mm_fp6_format.fd; mips32_insn.fp6_format.func = func; break; case mm_32f_10_op: func = -1; /* Invalid */ op = insn.mm_fp5_format.op & 0x7; if (op == mm_ldxc1_op) func = ldxc1_op; else if (op == mm_sdxc1_op) func = sdxc1_op; else if (op == mm_lwxc1_op) func = lwxc1_op; else if (op == mm_swxc1_op) func = swxc1_op; if (func != -1) { mips32_insn.r_format.opcode = cop1x_op; mips32_insn.r_format.rs = insn.mm_fp5_format.base; mips32_insn.r_format.rt = insn.mm_fp5_format.index; mips32_insn.r_format.rd = 0; mips32_insn.r_format.re = insn.mm_fp5_format.fd; mips32_insn.r_format.func = func; } else return SIGILL; break; case mm_32f_40_op: op = -1; /* Invalid */ if (insn.mm_fp2_format.op == mm_fmovt_op) op = 1; else if (insn.mm_fp2_format.op == mm_fmovf_op) op = 0; if (op != -1) { mips32_insn.fp0_format.opcode = cop1_op; mips32_insn.fp0_format.fmt = sdps_format[insn.mm_fp2_format.fmt]; mips32_insn.fp0_format.ft = (insn.mm_fp2_format.cc<<2) + op; mips32_insn.fp0_format.fs = insn.mm_fp2_format.fs; mips32_insn.fp0_format.fd = insn.mm_fp2_format.fd; mips32_insn.fp0_format.func = fmovc_op; } else return SIGILL; break; case mm_32f_60_op: func = -1; /* Invalid */ if (insn.mm_fp0_format.op == mm_fadd_op) func = fadd_op; else if (insn.mm_fp0_format.op == mm_fsub_op) func = fsub_op; else if (insn.mm_fp0_format.op == mm_fmul_op) func = fmul_op; else if (insn.mm_fp0_format.op == mm_fdiv_op) func = fdiv_op; if (func != -1) { mips32_insn.fp0_format.opcode = cop1_op; mips32_insn.fp0_format.fmt = sdps_format[insn.mm_fp0_format.fmt]; mips32_insn.fp0_format.ft = insn.mm_fp0_format.ft; mips32_insn.fp0_format.fs = insn.mm_fp0_format.fs; mips32_insn.fp0_format.fd = insn.mm_fp0_format.fd; mips32_insn.fp0_format.func = func; } else return SIGILL; break; case mm_32f_70_op: func = -1; /* Invalid */ if (insn.mm_fp0_format.op == mm_fmovn_op) func = fmovn_op; else if (insn.mm_fp0_format.op == mm_fmovz_op) func = fmovz_op; if (func != -1) { mips32_insn.fp0_format.opcode = cop1_op; mips32_insn.fp0_format.fmt = sdps_format[insn.mm_fp0_format.fmt]; mips32_insn.fp0_format.ft = insn.mm_fp0_format.ft; mips32_insn.fp0_format.fs = insn.mm_fp0_format.fs; mips32_insn.fp0_format.fd = insn.mm_fp0_format.fd; mips32_insn.fp0_format.func = func; } else return SIGILL; break; case mm_32f_73_op: /* POOL32FXF */ switch (insn.mm_fp1_format.op) { case mm_movf0_op: case mm_movf1_op: case mm_movt0_op: case mm_movt1_op: if ((insn.mm_fp1_format.op & 0x7f) == mm_movf0_op) op = 0; else op = 1; mips32_insn.r_format.opcode = spec_op; mips32_insn.r_format.rs = insn.mm_fp4_format.fs; mips32_insn.r_format.rt = (insn.mm_fp4_format.cc << 2) + op; mips32_insn.r_format.rd = insn.mm_fp4_format.rt; mips32_insn.r_format.re = 0; mips32_insn.r_format.func = movc_op; break; case mm_fcvtd0_op: case mm_fcvtd1_op: case mm_fcvts0_op: case mm_fcvts1_op: if ((insn.mm_fp1_format.op & 0x7f) == mm_fcvtd0_op) { func = fcvtd_op; fmt = swl_format[insn.mm_fp3_format.fmt]; } else { func = fcvts_op; fmt = dwl_format[insn.mm_fp3_format.fmt]; } mips32_insn.fp0_format.opcode = cop1_op; mips32_insn.fp0_format.fmt = fmt; mips32_insn.fp0_format.ft = 0; mips32_insn.fp0_format.fs = insn.mm_fp3_format.fs; mips32_insn.fp0_format.fd = insn.mm_fp3_format.rt; mips32_insn.fp0_format.func = func; break; case mm_fmov0_op: case mm_fmov1_op: case mm_fabs0_op: case mm_fabs1_op: case mm_fneg0_op: case mm_fneg1_op: if ((insn.mm_fp1_format.op & 0x7f) == mm_fmov0_op) func = fmov_op; else if ((insn.mm_fp1_format.op & 0x7f) == mm_fabs0_op) func = fabs_op; else func = fneg_op; mips32_insn.fp0_format.opcode = cop1_op; mips32_insn.fp0_format.fmt = sdps_format[insn.mm_fp3_format.fmt]; mips32_insn.fp0_format.ft = 0; mips32_insn.fp0_format.fs = insn.mm_fp3_format.fs; mips32_insn.fp0_format.fd = insn.mm_fp3_format.rt; mips32_insn.fp0_format.func = func; break; case mm_ffloorl_op: case mm_ffloorw_op: case mm_fceill_op: case mm_fceilw_op: case mm_ftruncl_op: case mm_ftruncw_op: case mm_froundl_op: case mm_froundw_op: case mm_fcvtl_op: case mm_fcvtw_op: if (insn.mm_fp1_format.op == mm_ffloorl_op) func = ffloorl_op; else if (insn.mm_fp1_format.op == mm_ffloorw_op) func = ffloor_op; else if (insn.mm_fp1_format.op == mm_fceill_op) func = fceill_op; else if (insn.mm_fp1_format.op == mm_fceilw_op) func = fceil_op; else if (insn.mm_fp1_format.op == mm_ftruncl_op) func = ftruncl_op; else if (insn.mm_fp1_format.op == mm_ftruncw_op) func = ftrunc_op; else if (insn.mm_fp1_format.op == mm_froundl_op) func = froundl_op; else if (insn.mm_fp1_format.op == mm_froundw_op) func = fround_op; else if (insn.mm_fp1_format.op == mm_fcvtl_op) func = fcvtl_op; else func = fcvtw_op; mips32_insn.fp0_format.opcode = cop1_op; mips32_insn.fp0_format.fmt = sd_format[insn.mm_fp1_format.fmt]; mips32_insn.fp0_format.ft = 0; mips32_insn.fp0_format.fs = insn.mm_fp1_format.fs; mips32_insn.fp0_format.fd = insn.mm_fp1_format.rt; mips32_insn.fp0_format.func = func; break; case mm_frsqrt_op: case mm_fsqrt_op: case mm_frecip_op: if (insn.mm_fp1_format.op == mm_frsqrt_op) func = frsqrt_op; else if (insn.mm_fp1_format.op == mm_fsqrt_op) func = fsqrt_op; else func = frecip_op; mips32_insn.fp0_format.opcode = cop1_op; mips32_insn.fp0_format.fmt = sdps_format[insn.mm_fp1_format.fmt]; mips32_insn.fp0_format.ft = 0; mips32_insn.fp0_format.fs = insn.mm_fp1_format.fs; mips32_insn.fp0_format.fd = insn.mm_fp1_format.rt; mips32_insn.fp0_format.func = func; break; case mm_mfc1_op: case mm_mtc1_op: case mm_cfc1_op: case mm_ctc1_op: case mm_mfhc1_op: case mm_mthc1_op: if (insn.mm_fp1_format.op == mm_mfc1_op) op = mfc_op; else if (insn.mm_fp1_format.op == mm_mtc1_op) op = mtc_op; else if (insn.mm_fp1_format.op == mm_cfc1_op) op = cfc_op; else if (insn.mm_fp1_format.op == mm_ctc1_op) op = ctc_op; else if (insn.mm_fp1_format.op == mm_mfhc1_op) op = mfhc_op; else op = mthc_op; mips32_insn.fp1_format.opcode = cop1_op; mips32_insn.fp1_format.op = op; mips32_insn.fp1_format.rt = insn.mm_fp1_format.rt; mips32_insn.fp1_format.fs = insn.mm_fp1_format.fs; mips32_insn.fp1_format.fd = 0; mips32_insn.fp1_format.func = 0; break; default: return SIGILL; } break; case mm_32f_74_op: /* c.cond.fmt */ mips32_insn.fp0_format.opcode = cop1_op; mips32_insn.fp0_format.fmt = sdps_format[insn.mm_fp4_format.fmt]; mips32_insn.fp0_format.ft = insn.mm_fp4_format.rt; mips32_insn.fp0_format.fs = insn.mm_fp4_format.fs; mips32_insn.fp0_format.fd = insn.mm_fp4_format.cc << 2; mips32_insn.fp0_format.func = insn.mm_fp4_format.cond | MM_MIPS32_COND_FC; break; default: return SIGILL; } break; default: return SIGILL; } *insn_ptr = mips32_insn; return 0; } /* * 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(struct pt_regs *regs, struct mm_decoded_insn dec_insn, unsigned long *contpc) { union mips_instruction insn = (union mips_instruction)dec_insn.insn; unsigned int fcr31; unsigned int bit = 0; switch (insn.i_format.opcode) { case spec_op: switch (insn.r_format.func) { case jalr_op: if (insn.r_format.rd != 0) { regs->regs[insn.r_format.rd] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; } /* Fall through */ case jr_op: /* For R6, JR already emulated in jalr_op */ if (NO_R6EMU && insn.r_format.func == jr_op) break; *contpc = regs->regs[insn.r_format.rs]; return 1; } break; case bcond_op: switch (insn.i_format.rt) { case bltzal_op: case bltzall_op: if (NO_R6EMU && (insn.i_format.rs || insn.i_format.rt == bltzall_op)) break; regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; /* Fall through */ case bltzl_op: if (NO_R6EMU) break; case bltz_op: if ((long)regs->regs[insn.i_format.rs] < 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case bgezal_op: case bgezall_op: if (NO_R6EMU && (insn.i_format.rs || insn.i_format.rt == bgezall_op)) break; regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; /* Fall through */ case bgezl_op: if (NO_R6EMU) break; case bgez_op: if ((long)regs->regs[insn.i_format.rs] >= 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; } break; case jalx_op: set_isa16_mode(bit); case jal_op: regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; /* Fall through */ case j_op: *contpc = regs->cp0_epc + dec_insn.pc_inc; *contpc >>= 28; *contpc <<= 28; *contpc |= (insn.j_format.target << 2); /* Set microMIPS mode bit: XOR for jalx. */ *contpc ^= bit; return 1; case beql_op: if (NO_R6EMU) break; case beq_op: if (regs->regs[insn.i_format.rs] == regs->regs[insn.i_format.rt]) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case bnel_op: if (NO_R6EMU) break; case bne_op: if (regs->regs[insn.i_format.rs] != regs->regs[insn.i_format.rt]) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case blezl_op: if (!insn.i_format.rt && NO_R6EMU) break; case blez_op: /* * Compact branches for R6 for the * blez and blezl opcodes. * BLEZ | rs = 0 | rt != 0 == BLEZALC * BLEZ | rs = rt != 0 == BGEZALC * BLEZ | rs != 0 | rt != 0 == BGEUC * BLEZL | rs = 0 | rt != 0 == BLEZC * BLEZL | rs = rt != 0 == BGEZC * BLEZL | rs != 0 | rt != 0 == BGEC * * For real BLEZ{,L}, rt is always 0. */ if (cpu_has_mips_r6 && insn.i_format.rt) { if ((insn.i_format.opcode == blez_op) && ((!insn.i_format.rs && insn.i_format.rt) || (insn.i_format.rs == insn.i_format.rt))) regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc; *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; } if ((long)regs->regs[insn.i_format.rs] <= 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case bgtzl_op: if (!insn.i_format.rt && NO_R6EMU) break; case bgtz_op: /* * Compact branches for R6 for the * bgtz and bgtzl opcodes. * BGTZ | rs = 0 | rt != 0 == BGTZALC * BGTZ | rs = rt != 0 == BLTZALC * BGTZ | rs != 0 | rt != 0 == BLTUC * BGTZL | rs = 0 | rt != 0 == BGTZC * BGTZL | rs = rt != 0 == BLTZC * BGTZL | rs != 0 | rt != 0 == BLTC * * *ZALC varint for BGTZ &&& rt != 0 * For real GTZ{,L}, rt is always 0. */ if (cpu_has_mips_r6 && insn.i_format.rt) { if ((insn.i_format.opcode == blez_op) && ((!insn.i_format.rs && insn.i_format.rt) || (insn.i_format.rs == insn.i_format.rt))) regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc; *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; } if ((long)regs->regs[insn.i_format.rs] > 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case cbcond0_op: case cbcond1_op: if (!cpu_has_mips_r6) break; if (insn.i_format.rt && !insn.i_format.rs) regs->regs[31] = regs->cp0_epc + 4; *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; #ifdef CONFIG_CPU_CAVIUM_OCTEON case lwc2_op: /* This is bbit0 on Octeon */ if ((regs->regs[insn.i_format.rs] & (1ull<cp0_epc + 4 + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + 8; return 1; case ldc2_op: /* This is bbit032 on Octeon */ if ((regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) == 0) *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + 8; return 1; case swc2_op: /* This is bbit1 on Octeon */ if (regs->regs[insn.i_format.rs] & (1ull<cp0_epc + 4 + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + 8; return 1; case sdc2_op: /* This is bbit132 on Octeon */ if (regs->regs[insn.i_format.rs] & (1ull<<(insn.i_format.rt + 32))) *contpc = regs->cp0_epc + 4 + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + 8; return 1; #else case bc6_op: /* * Only valid for MIPS R6 but we can still end up * here from a broken userland so just tell emulator * this is not a branch and let it break later on. */ if (!cpu_has_mips_r6) break; *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case balc6_op: if (!cpu_has_mips_r6) break; regs->regs[31] = regs->cp0_epc + 4; *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case beqzcjic_op: if (!cpu_has_mips_r6) break; *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case bnezcjialc_op: if (!cpu_has_mips_r6) break; if (!insn.i_format.rs) regs->regs[31] = regs->cp0_epc + 4; *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; #endif case cop0_op: case cop1_op: /* Need to check for R6 bc1nez and bc1eqz branches */ if (cpu_has_mips_r6 && ((insn.i_format.rs == bc1eqz_op) || (insn.i_format.rs == bc1nez_op))) { bit = 0; switch (insn.i_format.rs) { case bc1eqz_op: if (get_fpr32(¤t->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1) bit = 1; break; case bc1nez_op: if (!(get_fpr32(¤t->thread.fpu.fpr[insn.i_format.rt], 0) & 0x1)) bit = 1; break; } if (bit) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; } /* R2/R6 compatible cop1 instruction. Fall through */ case cop2_op: case cop1x_op: if (insn.i_format.rs == bc_op) { preempt_disable(); if (is_fpu_owner()) fcr31 = read_32bit_cp1_register(CP1_STATUS); else fcr31 = current->thread.fpu.fcr31; preempt_enable(); bit = (insn.i_format.rt >> 2); bit += (bit != 0); bit += 23; switch (insn.i_format.rt & 3) { case 0: /* bc1f */ case 2: /* bc1fl */ if (~fcr31 & (1 << bit)) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case 1: /* bc1t */ case 3: /* bc1tl */ if (fcr31 & (1 << bit)) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.i_format.simmediate << 2); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; } } break; } return 0; } /* * In the Linux kernel, we support selection of FPR format on the * basis of the Status.FR bit. If an FPU is not present, the FR bit * is hardwired to zero, which would imply a 32-bit FPU even for * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS. * FPU emu is slow and bulky and optimizing this function offers fairly * sizeable benefits so we try to be clever and make this function return * a constant whenever possible, that is on 64-bit kernels without O32 * compatibility enabled and on 32-bit without 64-bit FPU support. */ static inline int cop1_64bit(struct pt_regs *xcp) { if (config_enabled(CONFIG_64BIT) && !config_enabled(CONFIG_MIPS32_O32)) return 1; else if (config_enabled(CONFIG_32BIT) && !config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT)) return 0; return !test_thread_flag(TIF_32BIT_FPREGS); } static inline bool hybrid_fprs(void) { return test_thread_flag(TIF_HYBRID_FPREGS); } #define SIFROMREG(si, x) \ do { \ if (cop1_64bit(xcp) && !hybrid_fprs()) \ (si) = (int)get_fpr32(&ctx->fpr[x], 0); \ else \ (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \ } while (0) #define SITOREG(si, x) \ do { \ if (cop1_64bit(xcp) && !hybrid_fprs()) { \ unsigned i; \ set_fpr32(&ctx->fpr[x], 0, si); \ for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \ set_fpr32(&ctx->fpr[x], i, 0); \ } else { \ set_fpr32(&ctx->fpr[(x) & ~1], (x) & 1, si); \ } \ } while (0) #define SIFROMHREG(si, x) ((si) = (int)get_fpr32(&ctx->fpr[x], 1)) #define SITOHREG(si, x) \ do { \ unsigned i; \ set_fpr32(&ctx->fpr[x], 1, si); \ for (i = 2; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \ set_fpr32(&ctx->fpr[x], i, 0); \ } while (0) #define DIFROMREG(di, x) \ ((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) ^ 1)], 0)) #define DITOREG(di, x) \ do { \ unsigned fpr, i; \ fpr = (x) & ~(cop1_64bit(xcp) ^ 1); \ set_fpr64(&ctx->fpr[fpr], 0, di); \ for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++) \ set_fpr64(&ctx->fpr[fpr], i, 0); \ } while (0) #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 a CFC1 instruction. */ static inline void cop1_cfc(struct pt_regs *xcp, struct mips_fpu_struct *ctx, mips_instruction ir) { u32 fcr31 = ctx->fcr31; u32 value = 0; switch (MIPSInst_RD(ir)) { case FPCREG_CSR: value = fcr31; pr_debug("%p gpr[%d]<-csr=%08x\n", (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); break; case FPCREG_FENR: if (!cpu_has_mips_r) break; value = (fcr31 >> (FPU_CSR_FS_S - MIPS_FENR_FS_S)) & MIPS_FENR_FS; value |= fcr31 & (FPU_CSR_ALL_E | FPU_CSR_RM); pr_debug("%p gpr[%d]<-enr=%08x\n", (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); break; case FPCREG_FEXR: if (!cpu_has_mips_r) break; value = fcr31 & (FPU_CSR_ALL_X | FPU_CSR_ALL_S); pr_debug("%p gpr[%d]<-exr=%08x\n", (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); break; case FPCREG_FCCR: if (!cpu_has_mips_r) break; value = (fcr31 >> (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) & MIPS_FCCR_COND0; value |= (fcr31 >> (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) & (MIPS_FCCR_CONDX & ~MIPS_FCCR_COND0); pr_debug("%p gpr[%d]<-ccr=%08x\n", (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); break; case FPCREG_RID: value = boot_cpu_data.fpu_id; break; default: break; } if (MIPSInst_RT(ir)) xcp->regs[MIPSInst_RT(ir)] = value; } /* * Emulate a CTC1 instruction. */ static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx, mips_instruction ir) { u32 fcr31 = ctx->fcr31; u32 value; u32 mask; if (MIPSInst_RT(ir) == 0) value = 0; else value = xcp->regs[MIPSInst_RT(ir)]; switch (MIPSInst_RD(ir)) { case FPCREG_CSR: pr_debug("%p gpr[%d]->csr=%08x\n", (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); /* Preserve read-only bits. */ mask = boot_cpu_data.fpu_msk31; fcr31 = (value & ~mask) | (fcr31 & mask); break; case FPCREG_FENR: if (!cpu_has_mips_r) break; pr_debug("%p gpr[%d]->enr=%08x\n", (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); fcr31 &= ~(FPU_CSR_FS | FPU_CSR_ALL_E | FPU_CSR_RM); fcr31 |= (value << (FPU_CSR_FS_S - MIPS_FENR_FS_S)) & FPU_CSR_FS; fcr31 |= value & (FPU_CSR_ALL_E | FPU_CSR_RM); break; case FPCREG_FEXR: if (!cpu_has_mips_r) break; pr_debug("%p gpr[%d]->exr=%08x\n", (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); fcr31 &= ~(FPU_CSR_ALL_X | FPU_CSR_ALL_S); fcr31 |= value & (FPU_CSR_ALL_X | FPU_CSR_ALL_S); break; case FPCREG_FCCR: if (!cpu_has_mips_r) break; pr_debug("%p gpr[%d]->ccr=%08x\n", (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); fcr31 &= ~(FPU_CSR_CONDX | FPU_CSR_COND); fcr31 |= (value << (FPU_CSR_COND_S - MIPS_FCCR_COND0_S)) & FPU_CSR_COND; fcr31 |= (value << (FPU_CSR_COND1_S - MIPS_FCCR_COND1_S)) & FPU_CSR_CONDX; break; default: break; } ctx->fcr31 = fcr31; } /* * 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, struct mm_decoded_insn dec_insn, void *__user *fault_addr) { unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc; unsigned int cond, cbit, bit0; mips_instruction ir; int likely, pc_inc; union fpureg *fpr; u32 __user *wva; u64 __user *dva; u32 wval; u64 dval; int sig; /* * These are giving gcc a gentle hint about what to expect in * dec_inst in order to do better optimization. */ if (!cpu_has_mmips && dec_insn.micro_mips_mode) unreachable(); /* XXX NEC Vr54xx bug workaround */ if (delay_slot(xcp)) { if (dec_insn.micro_mips_mode) { if (!mm_isBranchInstr(xcp, dec_insn, &contpc)) clear_delay_slot(xcp); } else { if (!isBranchInstr(xcp, dec_insn, &contpc)) clear_delay_slot(xcp); } } if (delay_slot(xcp)) { /* * 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. */ ir = dec_insn.next_insn; /* process delay slot instr */ pc_inc = dec_insn.next_pc_inc; } else { ir = dec_insn.insn; /* process current instr */ pc_inc = dec_insn.pc_inc; } /* * Since microMIPS FPU instructios are a subset of MIPS32 FPU * instructions, we want to convert microMIPS FPU instructions * into MIPS32 instructions so that we could reuse all of the * FPU emulation code. * * NOTE: We cannot do this for branch instructions since they * are not a subset. Example: Cannot emulate a 16-bit * aligned target address with a MIPS32 instruction. */ if (dec_insn.micro_mips_mode) { /* * If next instruction is a 16-bit instruction, then it * it cannot be a FPU instruction. This could happen * since we can be called for non-FPU instructions. */ if ((pc_inc == 2) || (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) return SIGILL; } emul: perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, xcp, 0); MIPS_FPU_EMU_INC_STATS(emulated); switch (MIPSInst_OPCODE(ir)) { case ldc1_op: dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); MIPS_FPU_EMU_INC_STATS(loads); if (!access_ok(VERIFY_READ, dva, sizeof(u64))) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = dva; return SIGBUS; } if (__get_user(dval, dva)) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = dva; return SIGSEGV; } DITOREG(dval, MIPSInst_RT(ir)); break; case sdc1_op: dva = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); MIPS_FPU_EMU_INC_STATS(stores); DIFROMREG(dval, MIPSInst_RT(ir)); if (!access_ok(VERIFY_WRITE, dva, sizeof(u64))) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = dva; return SIGBUS; } if (__put_user(dval, dva)) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = dva; return SIGSEGV; } break; case lwc1_op: wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); MIPS_FPU_EMU_INC_STATS(loads); if (!access_ok(VERIFY_READ, wva, sizeof(u32))) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = wva; return SIGBUS; } if (__get_user(wval, wva)) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = wva; return SIGSEGV; } SITOREG(wval, MIPSInst_RT(ir)); break; case swc1_op: wva = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); MIPS_FPU_EMU_INC_STATS(stores); SIFROMREG(wval, MIPSInst_RT(ir)); if (!access_ok(VERIFY_WRITE, wva, sizeof(u32))) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = wva; return SIGBUS; } if (__put_user(wval, wva)) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = wva; return SIGSEGV; } break; case cop1_op: switch (MIPSInst_RS(ir)) { case dmfc_op: if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) return SIGILL; /* copregister fs -> gpr[rt] */ if (MIPSInst_RT(ir) != 0) { DIFROMREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); } break; case dmtc_op: if (!cpu_has_mips_3_4_5 && !cpu_has_mips64) return SIGILL; /* copregister fs <- rt */ DITOREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); break; case mfhc_op: if (!cpu_has_mips_r2_r6) goto sigill; /* copregister rd -> gpr[rt] */ if (MIPSInst_RT(ir) != 0) { SIFROMHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); } break; case mthc_op: if (!cpu_has_mips_r2_r6) goto sigill; /* copregister rd <- gpr[rt] */ SITOHREG(xcp->regs[MIPSInst_RT(ir)], MIPSInst_RD(ir)); break; 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] */ cop1_cfc(xcp, ctx, ir); break; case ctc_op: /* copregister rd <- rt */ cop1_ctc(xcp, ctx, ir); if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { return SIGFPE; } break; case bc1eqz_op: case bc1nez_op: if (!cpu_has_mips_r6 || delay_slot(xcp)) return SIGILL; cond = likely = 0; fpr = ¤t->thread.fpu.fpr[MIPSInst_RT(ir)]; bit0 = get_fpr32(fpr, 0) & 0x1; switch (MIPSInst_RS(ir)) { case bc1eqz_op: cond = bit0 == 0; break; case bc1nez_op: cond = bit0 != 0; break; } goto branch_common; case bc_op: if (delay_slot(xcp)) return SIGILL; if (cpu_has_mips_4_5_r) cbit = fpucondbit[MIPSInst_RT(ir) >> 2]; else cbit = FPU_CSR_COND; cond = ctx->fcr31 & cbit; likely = 0; switch (MIPSInst_RT(ir) & 3) { case bcfl_op: if (cpu_has_mips_2_3_4_5_r) likely = 1; /* Fall through */ case bcf_op: cond = !cond; break; case bctl_op: if (cpu_has_mips_2_3_4_5_r) likely = 1; /* Fall through */ case bct_op: break; } branch_common: set_delay_slot(xcp); if (cond) { /* * Branch taken: emulate dslot instruction */ unsigned long bcpc; /* * Remember EPC at the branch to point back * at so that any delay-slot instruction * signal is not silently ignored. */ bcpc = xcp->cp0_epc; xcp->cp0_epc += dec_insn.pc_inc; contpc = MIPSInst_SIMM(ir); ir = dec_insn.next_insn; if (dec_insn.micro_mips_mode) { contpc = (xcp->cp0_epc + (contpc << 1)); /* If 16-bit instruction, not FPU. */ if ((dec_insn.next_pc_inc == 2) || (microMIPS32_to_MIPS32((union mips_instruction *)&ir) == SIGILL)) { /* * Since this instruction will * be put on the stack with * 32-bit words, get around * this problem by putting a * NOP16 as the second one. */ if (dec_insn.next_pc_inc == 2) ir = (ir & (~0xffff)) | MM_NOP16; /* * Single step the non-CP1 * instruction in the dslot. */ sig = mips_dsemul(xcp, ir, contpc); if (sig) xcp->cp0_epc = bcpc; /* * SIGILL forces out of * the emulation loop. */ return sig ? sig : SIGILL; } } else contpc = (xcp->cp0_epc + (contpc << 2)); switch (MIPSInst_OPCODE(ir)) { case lwc1_op: case swc1_op: goto emul; case ldc1_op: case sdc1_op: if (cpu_has_mips_2_3_4_5_r) goto emul; goto bc_sigill; case cop1_op: goto emul; case cop1x_op: if (cpu_has_mips_4_5_64_r2_r6) /* its one of ours */ goto emul; goto bc_sigill; case spec_op: switch (MIPSInst_FUNC(ir)) { case movc_op: if (cpu_has_mips_4_5_r) goto emul; goto bc_sigill; } break; bc_sigill: xcp->cp0_epc = bcpc; return SIGILL; } /* * Single step the non-cp1 * instruction in the dslot */ sig = mips_dsemul(xcp, ir, contpc); if (sig) xcp->cp0_epc = bcpc; /* SIGILL forces out of the emulation loop. */ return sig ? sig : SIGILL; } else if (likely) { /* branch not taken */ /* * branch likely nullifies * dslot if not taken */ xcp->cp0_epc += dec_insn.pc_inc; contpc += dec_insn.pc_inc; /* * else continue & execute * dslot as normal insn */ } break; default: if (!(MIPSInst_RS(ir) & 0x10)) return SIGILL; /* a real fpu computation instruction */ if ((sig = fpu_emu(xcp, ctx, ir))) return sig; } break; case cop1x_op: if (!cpu_has_mips_4_5_64_r2_r6) return SIGILL; sig = fpux_emu(xcp, ctx, ir, fault_addr); if (sig) return sig; break; case spec_op: if (!cpu_has_mips_4_5_r) return SIGILL; 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; default: sigill: return SIGILL; } /* we did it !! */ xcp->cp0_epc = contpc; clear_delay_slot(xcp); 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 */ }; static const unsigned char negative_cmptab[8] = { 0, /* Reserved */ IEEE754_CLT | IEEE754_CGT | IEEE754_CEQ, IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, IEEE754_CLT | IEEE754_CGT, /* Reserved */ }; /* * Additional MIPS4 instructions */ #define DEF3OP(name, p, f1, f2, f3) \ static union ieee754##p fpemu_##p##_##name(union ieee754##p r, \ union ieee754##p s, union 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 union ieee754dp fpemu_dp_recip(union ieee754dp d) { return ieee754dp_div(ieee754dp_one(0), d); } static union ieee754dp fpemu_dp_rsqrt(union ieee754dp d) { return ieee754dp_div(ieee754dp_one(0), ieee754dp_sqrt(d)); } static union ieee754sp fpemu_sp_recip(union ieee754sp s) { return ieee754sp_div(ieee754sp_one(0), s); } static union ieee754sp fpemu_sp_rsqrt(union 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, void *__user *fault_addr) { unsigned rcsr = 0; /* resulting csr */ MIPS_FPU_EMU_INC_STATS(cp1xops); switch (MIPSInst_FMA_FFMT(ir)) { case s_fmt:{ /* 0 */ union ieee754sp(*handler) (union ieee754sp, union ieee754sp, union ieee754sp); union 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)]); MIPS_FPU_EMU_INC_STATS(loads); if (!access_ok(VERIFY_READ, va, sizeof(u32))) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = va; return SIGBUS; } if (__get_user(val, va)) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = va; return SIGSEGV; } SITOREG(val, MIPSInst_FD(ir)); break; case swxc1_op: va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + xcp->regs[MIPSInst_FT(ir)]); MIPS_FPU_EMU_INC_STATS(stores); SIFROMREG(val, MIPSInst_FS(ir)); if (!access_ok(VERIFY_WRITE, va, sizeof(u32))) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = va; return SIGBUS; } if (put_user(val, va)) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = va; return SIGSEGV; } 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)) { MIPS_FPU_EMU_INC_STATS(ieee754_inexact); rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S; } if (ieee754_cxtest(IEEE754_UNDERFLOW)) { MIPS_FPU_EMU_INC_STATS(ieee754_underflow); rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S; } if (ieee754_cxtest(IEEE754_OVERFLOW)) { MIPS_FPU_EMU_INC_STATS(ieee754_overflow); rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S; } if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) { MIPS_FPU_EMU_INC_STATS(ieee754_invalidop); 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 */ union ieee754dp(*handler) (union ieee754dp, union ieee754dp, union ieee754dp); union 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)]); MIPS_FPU_EMU_INC_STATS(loads); if (!access_ok(VERIFY_READ, va, sizeof(u64))) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = va; return SIGBUS; } if (__get_user(val, va)) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = va; return SIGSEGV; } DITOREG(val, MIPSInst_FD(ir)); break; case sdxc1_op: va = (void __user *) (xcp->regs[MIPSInst_FR(ir)] + xcp->regs[MIPSInst_FT(ir)]); MIPS_FPU_EMU_INC_STATS(stores); DIFROMREG(val, MIPSInst_FS(ir)); if (!access_ok(VERIFY_WRITE, va, sizeof(u64))) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = va; return SIGBUS; } if (__put_user(val, va)) { MIPS_FPU_EMU_INC_STATS(errors); *fault_addr = va; return SIGSEGV; } 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 0x3: if (MIPSInst_FUNC(ir) != pfetch_op) return SIGILL; /* ignore prefx operation */ break; default: return SIGILL; } return 0; } /* * 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 int oldrm; unsigned int cbit; unsigned cond; union { union ieee754dp d; union ieee754sp s; int w; s64 l; } rv; /* resulting value */ u64 bits; MIPS_FPU_EMU_INC_STATS(cp1ops); switch (rfmt = (MIPSInst_FFMT(ir) & 0xf)) { case s_fmt: { /* 0 */ union { union ieee754sp(*b) (union ieee754sp, union ieee754sp); union ieee754sp(*u) (union ieee754sp); } handler; union ieee754sp fs, ft; 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 */ case fsqrt_op: if (!cpu_has_mips_2_3_4_5_r) return SIGILL; handler.u = ieee754sp_sqrt; goto scopuop; /* * Note that on some MIPS IV implementations such as the * R5000 and R8000 the FSQRT and FRECIP instructions do not * achieve full IEEE-754 accuracy - however this emulator does. */ case frsqrt_op: if (!cpu_has_mips_4_5_64_r2_r6) return SIGILL; handler.u = fpemu_sp_rsqrt; goto scopuop; case frecip_op: if (!cpu_has_mips_4_5_64_r2_r6) return SIGILL; handler.u = fpemu_sp_recip; goto scopuop; case fmovc_op: if (!cpu_has_mips_4_5_r) return SIGILL; 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 (!cpu_has_mips_4_5_r) return SIGILL; if (xcp->regs[MIPSInst_FT(ir)] != 0) return 0; SPFROMREG(rv.s, MIPSInst_FS(ir)); break; case fmovn_op: if (!cpu_has_mips_4_5_r) return SIGILL; if (xcp->regs[MIPSInst_FT(ir)] == 0) return 0; SPFROMREG(rv.s, MIPSInst_FS(ir)); break; case fseleqz_op: if (!cpu_has_mips_r6) return SIGILL; SPFROMREG(rv.s, MIPSInst_FT(ir)); if (rv.w & 0x1) rv.w = 0; else SPFROMREG(rv.s, MIPSInst_FS(ir)); break; case fselnez_op: if (!cpu_has_mips_r6) return SIGILL; SPFROMREG(rv.s, MIPSInst_FT(ir)); if (rv.w & 0x1) SPFROMREG(rv.s, MIPSInst_FS(ir)); else rv.w = 0; break; case fmaddf_op: { union ieee754sp ft, fs, fd; if (!cpu_has_mips_r6) return SIGILL; SPFROMREG(ft, MIPSInst_FT(ir)); SPFROMREG(fs, MIPSInst_FS(ir)); SPFROMREG(fd, MIPSInst_FD(ir)); rv.s = ieee754sp_maddf(fd, fs, ft); goto copcsr; } case fmsubf_op: { union ieee754sp ft, fs, fd; if (!cpu_has_mips_r6) return SIGILL; SPFROMREG(ft, MIPSInst_FT(ir)); SPFROMREG(fs, MIPSInst_FS(ir)); SPFROMREG(fd, MIPSInst_FD(ir)); rv.s = ieee754sp_msubf(fd, fs, ft); goto copcsr; } case frint_op: { union ieee754sp fs; if (!cpu_has_mips_r6) return SIGILL; SPFROMREG(fs, MIPSInst_FS(ir)); rv.l = ieee754sp_tlong(fs); rv.s = ieee754sp_flong(rv.l); goto copcsr; } case fclass_op: { union ieee754sp fs; if (!cpu_has_mips_r6) return SIGILL; SPFROMREG(fs, MIPSInst_FS(ir)); rv.w = ieee754sp_2008class(fs); rfmt = w_fmt; goto copcsr; } case fmin_op: { union ieee754sp fs, ft; if (!cpu_has_mips_r6) return SIGILL; SPFROMREG(ft, MIPSInst_FT(ir)); SPFROMREG(fs, MIPSInst_FS(ir)); rv.s = ieee754sp_fmin(fs, ft); goto copcsr; } case fmina_op: { union ieee754sp fs, ft; if (!cpu_has_mips_r6) return SIGILL; SPFROMREG(ft, MIPSInst_FT(ir)); SPFROMREG(fs, MIPSInst_FS(ir)); rv.s = ieee754sp_fmina(fs, ft); goto copcsr; } case fmax_op: { union ieee754sp fs, ft; if (!cpu_has_mips_r6) return SIGILL; SPFROMREG(ft, MIPSInst_FT(ir)); SPFROMREG(fs, MIPSInst_FS(ir)); rv.s = ieee754sp_fmax(fs, ft); goto copcsr; } case fmaxa_op: { union ieee754sp fs, ft; if (!cpu_has_mips_r6) return SIGILL; SPFROMREG(ft, MIPSInst_FT(ir)); SPFROMREG(fs, MIPSInst_FS(ir)); rv.s = ieee754sp_fmaxa(fs, ft); goto copcsr; } 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: SPFROMREG(fs, MIPSInst_FS(ir)); SPFROMREG(ft, MIPSInst_FT(ir)); rv.s = (*handler.b) (fs, ft); goto copcsr; scopuop: SPFROMREG(fs, MIPSInst_FS(ir)); rv.s = (*handler.u) (fs); goto copcsr; copcsr: if (ieee754_cxtest(IEEE754_INEXACT)) { MIPS_FPU_EMU_INC_STATS(ieee754_inexact); rcsr |= FPU_CSR_INE_X | FPU_CSR_INE_S; } if (ieee754_cxtest(IEEE754_UNDERFLOW)) { MIPS_FPU_EMU_INC_STATS(ieee754_underflow); rcsr |= FPU_CSR_UDF_X | FPU_CSR_UDF_S; } if (ieee754_cxtest(IEEE754_OVERFLOW)) { MIPS_FPU_EMU_INC_STATS(ieee754_overflow); rcsr |= FPU_CSR_OVF_X | FPU_CSR_OVF_S; } if (ieee754_cxtest(IEEE754_ZERO_DIVIDE)) { MIPS_FPU_EMU_INC_STATS(ieee754_zerodiv); rcsr |= FPU_CSR_DIV_X | FPU_CSR_DIV_S; } if (ieee754_cxtest(IEEE754_INVALID_OPERATION)) { MIPS_FPU_EMU_INC_STATS(ieee754_invalidop); rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S; } break; /* unary conv ops */ case fcvts_op: return SIGILL; /* not defined */ case fcvtd_op: SPFROMREG(fs, MIPSInst_FS(ir)); rv.d = ieee754dp_fsp(fs); rfmt = d_fmt; goto copcsr; case fcvtw_op: SPFROMREG(fs, MIPSInst_FS(ir)); rv.w = ieee754sp_tint(fs); rfmt = w_fmt; goto copcsr; case fround_op: case ftrunc_op: case fceil_op: case ffloor_op: if (!cpu_has_mips_2_3_4_5_r) return SIGILL; oldrm = ieee754_csr.rm; SPFROMREG(fs, MIPSInst_FS(ir)); ieee754_csr.rm = MIPSInst_FUNC(ir); rv.w = ieee754sp_tint(fs); ieee754_csr.rm = oldrm; rfmt = w_fmt; goto copcsr; case fcvtl_op: if (!cpu_has_mips_3_4_5_64_r2_r6) return SIGILL; 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: if (!cpu_has_mips_3_4_5_64_r2_r6) return SIGILL; oldrm = ieee754_csr.rm; SPFROMREG(fs, MIPSInst_FS(ir)); ieee754_csr.rm = MIPSInst_FUNC(ir); rv.l = ieee754sp_tlong(fs); ieee754_csr.rm = oldrm; rfmt = l_fmt; goto copcsr; default: if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) { unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op; union 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 fs, ft; union { union ieee754dp(*b) (union ieee754dp, union ieee754dp); union ieee754dp(*u) (union 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 */ case fsqrt_op: if (!cpu_has_mips_2_3_4_5_r) return SIGILL; handler.u = ieee754dp_sqrt; goto dcopuop; /* * Note that on some MIPS IV implementations such as the * R5000 and R8000 the FSQRT and FRECIP instructions do not * achieve full IEEE-754 accuracy - however this emulator does. */ case frsqrt_op: if (!cpu_has_mips_4_5_64_r2_r6) return SIGILL; handler.u = fpemu_dp_rsqrt; goto dcopuop; case frecip_op: if (!cpu_has_mips_4_5_64_r2_r6) return SIGILL; handler.u = fpemu_dp_recip; goto dcopuop; case fmovc_op: if (!cpu_has_mips_4_5_r) return SIGILL; 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 (!cpu_has_mips_4_5_r) return SIGILL; if (xcp->regs[MIPSInst_FT(ir)] != 0) return 0; DPFROMREG(rv.d, MIPSInst_FS(ir)); break; case fmovn_op: if (!cpu_has_mips_4_5_r) return SIGILL; if (xcp->regs[MIPSInst_FT(ir)] == 0) return 0; DPFROMREG(rv.d, MIPSInst_FS(ir)); break; case fseleqz_op: if (!cpu_has_mips_r6) return SIGILL; DPFROMREG(rv.d, MIPSInst_FT(ir)); if (rv.l & 0x1) rv.l = 0; else DPFROMREG(rv.d, MIPSInst_FS(ir)); break; case fselnez_op: if (!cpu_has_mips_r6) return SIGILL; DPFROMREG(rv.d, MIPSInst_FT(ir)); if (rv.l & 0x1) DPFROMREG(rv.d, MIPSInst_FS(ir)); else rv.l = 0; break; case fmaddf_op: { union ieee754dp ft, fs, fd; if (!cpu_has_mips_r6) return SIGILL; DPFROMREG(ft, MIPSInst_FT(ir)); DPFROMREG(fs, MIPSInst_FS(ir)); DPFROMREG(fd, MIPSInst_FD(ir)); rv.d = ieee754dp_maddf(fd, fs, ft); goto copcsr; } case fmsubf_op: { union ieee754dp ft, fs, fd; if (!cpu_has_mips_r6) return SIGILL; DPFROMREG(ft, MIPSInst_FT(ir)); DPFROMREG(fs, MIPSInst_FS(ir)); DPFROMREG(fd, MIPSInst_FD(ir)); rv.d = ieee754dp_msubf(fd, fs, ft); goto copcsr; } case frint_op: { union ieee754dp fs; if (!cpu_has_mips_r6) return SIGILL; DPFROMREG(fs, MIPSInst_FS(ir)); rv.l = ieee754dp_tlong(fs); rv.d = ieee754dp_flong(rv.l); goto copcsr; } case fclass_op: { union ieee754dp fs; if (!cpu_has_mips_r6) return SIGILL; DPFROMREG(fs, MIPSInst_FS(ir)); rv.w = ieee754dp_2008class(fs); rfmt = w_fmt; goto copcsr; } case fmin_op: { union ieee754dp fs, ft; if (!cpu_has_mips_r6) return SIGILL; DPFROMREG(ft, MIPSInst_FT(ir)); DPFROMREG(fs, MIPSInst_FS(ir)); rv.d = ieee754dp_fmin(fs, ft); goto copcsr; } case fmina_op: { union ieee754dp fs, ft; if (!cpu_has_mips_r6) return SIGILL; DPFROMREG(ft, MIPSInst_FT(ir)); DPFROMREG(fs, MIPSInst_FS(ir)); rv.d = ieee754dp_fmina(fs, ft); goto copcsr; } case fmax_op: { union ieee754dp fs, ft; if (!cpu_has_mips_r6) return SIGILL; DPFROMREG(ft, MIPSInst_FT(ir)); DPFROMREG(fs, MIPSInst_FS(ir)); rv.d = ieee754dp_fmax(fs, ft); goto copcsr; } case fmaxa_op: { union ieee754dp fs, ft; if (!cpu_has_mips_r6) return SIGILL; DPFROMREG(ft, MIPSInst_FT(ir)); DPFROMREG(fs, MIPSInst_FS(ir)); rv.d = ieee754dp_fmaxa(fs, ft); goto copcsr; } 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: DPFROMREG(fs, MIPSInst_FS(ir)); DPFROMREG(ft, MIPSInst_FT(ir)); rv.d = (*handler.b) (fs, ft); goto copcsr; dcopuop: DPFROMREG(fs, MIPSInst_FS(ir)); rv.d = (*handler.u) (fs); goto copcsr; /* * unary conv ops */ case fcvts_op: 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: DPFROMREG(fs, MIPSInst_FS(ir)); rv.w = ieee754dp_tint(fs); /* wrong */ rfmt = w_fmt; goto copcsr; case fround_op: case ftrunc_op: case fceil_op: case ffloor_op: if (!cpu_has_mips_2_3_4_5_r) return SIGILL; oldrm = ieee754_csr.rm; DPFROMREG(fs, MIPSInst_FS(ir)); ieee754_csr.rm = MIPSInst_FUNC(ir); rv.w = ieee754dp_tint(fs); ieee754_csr.rm = oldrm; rfmt = w_fmt; goto copcsr; case fcvtl_op: if (!cpu_has_mips_3_4_5_64_r2_r6) return SIGILL; 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: if (!cpu_has_mips_3_4_5_64_r2_r6) return SIGILL; oldrm = ieee754_csr.rm; DPFROMREG(fs, MIPSInst_FS(ir)); ieee754_csr.rm = MIPSInst_FUNC(ir); rv.l = ieee754dp_tlong(fs); ieee754_csr.rm = oldrm; rfmt = l_fmt; goto copcsr; default: if (!NO_R6EMU && MIPSInst_FUNC(ir) >= fcmp_op) { unsigned cmpop = MIPSInst_FUNC(ir) - fcmp_op; union 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: { union ieee754dp 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: { /* Emulating the new CMP.condn.fmt R6 instruction */ #define CMPOP_MASK 0x7 #define SIGN_BIT (0x1 << 3) #define PREDICATE_BIT (0x1 << 4) int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK; int sig = MIPSInst_FUNC(ir) & SIGN_BIT; union ieee754sp fs, ft; /* This is an R6 only instruction */ if (!cpu_has_mips_r6 || (MIPSInst_FUNC(ir) & 0x20)) return SIGILL; /* fmt is w_fmt for single precision so fix it */ rfmt = s_fmt; /* default to false */ rv.w = 0; /* CMP.condn.S */ SPFROMREG(fs, MIPSInst_FS(ir)); SPFROMREG(ft, MIPSInst_FT(ir)); /* positive predicates */ if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) { if (ieee754sp_cmp(fs, ft, cmptab[cmpop], sig)) rv.w = -1; /* true, all 1s */ if ((sig) && ieee754_cxtest(IEEE754_INVALID_OPERATION)) rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; else goto copcsr; } else { /* negative predicates */ switch (cmpop) { case 1: case 2: case 3: if (ieee754sp_cmp(fs, ft, negative_cmptab[cmpop], sig)) rv.w = -1; /* true, all 1s */ if (sig && ieee754_cxtest(IEEE754_INVALID_OPERATION)) rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; else goto copcsr; break; default: /* Reserved R6 ops */ return SIGILL; } } break; } } } case l_fmt: if (!cpu_has_mips_3_4_5_64_r2_r6) return SIGILL; DIFROMREG(bits, MIPSInst_FS(ir)); switch (MIPSInst_FUNC(ir)) { case fcvts_op: /* convert long to single precision real */ rv.s = ieee754sp_flong(bits); rfmt = s_fmt; goto copcsr; case fcvtd_op: /* convert long to double precision real */ rv.d = ieee754dp_flong(bits); rfmt = d_fmt; goto copcsr; default: { /* Emulating the new CMP.condn.fmt R6 instruction */ int cmpop = MIPSInst_FUNC(ir) & CMPOP_MASK; int sig = MIPSInst_FUNC(ir) & SIGN_BIT; union ieee754dp fs, ft; if (!cpu_has_mips_r6 || (MIPSInst_FUNC(ir) & 0x20)) return SIGILL; /* fmt is l_fmt for double precision so fix it */ rfmt = d_fmt; /* default to false */ rv.l = 0; /* CMP.condn.D */ DPFROMREG(fs, MIPSInst_FS(ir)); DPFROMREG(ft, MIPSInst_FT(ir)); /* positive predicates */ if (!(MIPSInst_FUNC(ir) & PREDICATE_BIT)) { if (ieee754dp_cmp(fs, ft, cmptab[cmpop], sig)) rv.l = -1LL; /* true, all 1s */ if (sig && ieee754_cxtest(IEEE754_INVALID_OPERATION)) rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; else goto copcsr; } else { /* negative predicates */ switch (cmpop) { case 1: case 2: case 3: if (ieee754dp_cmp(fs, ft, negative_cmptab[cmpop], sig)) rv.l = -1LL; /* true, all 1s */ if (sig && ieee754_cxtest(IEEE754_INVALID_OPERATION)) rcsr = FPU_CSR_INV_X | FPU_CSR_INV_S; else goto copcsr; break; default: /* Reserved R6 ops */ return SIGILL; } } break; } } 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 (cpu_has_mips_4_5_r) cbit = fpucondbit[MIPSInst_FD(ir) >> 2]; else cbit = FPU_CSR_COND; if (rv.w) ctx->fcr31 |= cbit; else ctx->fcr31 &= ~cbit; 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; case l_fmt: if (!cpu_has_mips_3_4_5_64_r2_r6) return SIGILL; DITOREG(rv.l, MIPSInst_FD(ir)); break; default: return SIGILL; } return 0; } /* * Emulate FPU instructions. * * If we use FPU hardware, then we have been typically called to handle * an unimplemented operation, such as where an operand is a NaN or * denormalized. In that case exit the emulation loop after a single * iteration so as to let hardware execute any subsequent instructions. * * If we have no FPU hardware or it has been disabled, then continue * emulating floating-point instructions until one of these conditions * has occurred: * * - a non-FPU instruction has been encountered, * * - an attempt to emulate has ended with a signal, * * - the ISA mode has been switched. * * We need to terminate the emulation loop if we got switched to the * MIPS16 mode, whether supported or not, so that we do not attempt * to emulate a MIPS16 instruction as a regular MIPS FPU instruction. * Similarly if we got switched to the microMIPS mode and only the * regular MIPS mode is supported, so that we do not attempt to emulate * a microMIPS instruction as a regular MIPS FPU instruction. Or if * we got switched to the regular MIPS mode and only the microMIPS mode * is supported, so that we do not attempt to emulate a regular MIPS * instruction that should cause an Address Error exception instead. * For simplicity we always terminate upon an ISA mode switch. */ int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx, int has_fpu, void *__user *fault_addr) { unsigned long oldepc, prevepc; struct mm_decoded_insn dec_insn; u16 instr[4]; u16 *instr_ptr; int sig = 0; oldepc = xcp->cp0_epc; do { prevepc = xcp->cp0_epc; if (get_isa16_mode(prevepc) && cpu_has_mmips) { /* * Get next 2 microMIPS instructions and convert them * into 32-bit instructions. */ if ((get_user(instr[0], (u16 __user *)msk_isa16_mode(xcp->cp0_epc))) || (get_user(instr[1], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 2))) || (get_user(instr[2], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 4))) || (get_user(instr[3], (u16 __user *)msk_isa16_mode(xcp->cp0_epc + 6)))) { MIPS_FPU_EMU_INC_STATS(errors); return SIGBUS; } instr_ptr = instr; /* Get first instruction. */ if (mm_insn_16bit(*instr_ptr)) { /* Duplicate the half-word. */ dec_insn.insn = (*instr_ptr << 16) | (*instr_ptr); /* 16-bit instruction. */ dec_insn.pc_inc = 2; instr_ptr += 1; } else { dec_insn.insn = (*instr_ptr << 16) | *(instr_ptr+1); /* 32-bit instruction. */ dec_insn.pc_inc = 4; instr_ptr += 2; } /* Get second instruction. */ if (mm_insn_16bit(*instr_ptr)) { /* Duplicate the half-word. */ dec_insn.next_insn = (*instr_ptr << 16) | (*instr_ptr); /* 16-bit instruction. */ dec_insn.next_pc_inc = 2; } else { dec_insn.next_insn = (*instr_ptr << 16) | *(instr_ptr+1); /* 32-bit instruction. */ dec_insn.next_pc_inc = 4; } dec_insn.micro_mips_mode = 1; } else { if ((get_user(dec_insn.insn, (mips_instruction __user *) xcp->cp0_epc)) || (get_user(dec_insn.next_insn, (mips_instruction __user *)(xcp->cp0_epc+4)))) { MIPS_FPU_EMU_INC_STATS(errors); return SIGBUS; } dec_insn.pc_inc = 4; dec_insn.next_pc_inc = 4; dec_insn.micro_mips_mode = 0; } if ((dec_insn.insn == 0) || ((dec_insn.pc_inc == 2) && ((dec_insn.insn & 0xffff) == MM_NOP16))) xcp->cp0_epc += dec_insn.pc_inc; /* Skip NOPs */ else { /* * The 'ieee754_csr' is an alias of ctx->fcr31. * No need to copy ctx->fcr31 to ieee754_csr. */ sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr); } if (has_fpu) break; if (sig) break; /* * We have to check for the ISA bit explicitly here, * because `get_isa16_mode' may return 0 if support * for code compression has been globally disabled, * or otherwise we may produce the wrong signal or * even proceed successfully where we must not. */ if ((xcp->cp0_epc ^ prevepc) & 0x1) 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; }