/* * 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., * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ieee754.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, void *__user *); #endif /* Further private data for which no space exists in mips_fpu_struct */ #ifdef CONFIG_DEBUG_FS DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats); #endif /* Control registers */ #define FPCREG_RID 0 /* $0 = revision id */ #define FPCREG_CSR 31 /* $31 = csr */ /* Determine rounding mode from the RM bits of the FCSR */ #define modeindex(v) ((v) & FPU_CSR_RM) /* microMIPS bitfields */ #define MM_POOL32A_MINOR_MASK 0x3f #define MM_POOL32A_MINOR_SHIFT 0x6 #define MM_MIPS32_COND_FC 0x30 /* 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 /* (microMIPS) Convert 16-bit register encoding to 32-bit register encoding. */ static const unsigned int reg16to32map[8] = {16, 17, 2, 3, 4, 5, 6, 7}; /* (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; } int mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, unsigned long *contpc) { union mips_instruction insn = (union mips_instruction)dec_insn.insn; int bc_false = 0; unsigned int fcr31; unsigned int bit; if (!cpu_has_mmips) return 0; switch (insn.mm_i_format.opcode) { case mm_pool32a_op: if ((insn.mm_i_format.simmediate & MM_POOL32A_MINOR_MASK) == mm_pool32axf_op) { switch (insn.mm_i_format.simmediate >> MM_POOL32A_MINOR_SHIFT) { case mm_jalr_op: case mm_jalrhb_op: case mm_jalrs_op: case mm_jalrshb_op: if (insn.mm_i_format.rt != 0) /* Not mm_jr */ regs->regs[insn.mm_i_format.rt] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; *contpc = regs->regs[insn.mm_i_format.rs]; return 1; } } break; case mm_pool32i_op: switch (insn.mm_i_format.rt) { case mm_bltzals_op: case mm_bltzal_op: regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; /* Fall through */ case mm_bltz_op: if ((long)regs->regs[insn.mm_i_format.rs] < 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.mm_i_format.simmediate << 1); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case mm_bgezals_op: case mm_bgezal_op: regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; /* Fall through */ case mm_bgez_op: if ((long)regs->regs[insn.mm_i_format.rs] >= 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.mm_i_format.simmediate << 1); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case mm_blez_op: if ((long)regs->regs[insn.mm_i_format.rs] <= 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.mm_i_format.simmediate << 1); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case mm_bgtz_op: if ((long)regs->regs[insn.mm_i_format.rs] <= 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.mm_i_format.simmediate << 1); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case mm_bc2f_op: case mm_bc1f_op: bc_false = 1; /* Fall through */ case mm_bc2t_op: case mm_bc1t_op: preempt_disable(); if (is_fpu_owner()) asm volatile("cfc1\t%0,$31" : "=r" (fcr31)); else fcr31 = current->thread.fpu.fcr31; preempt_enable(); if (bc_false) fcr31 = ~fcr31; bit = (insn.mm_i_format.rs >> 2); bit += (bit != 0); bit += 23; if (fcr31 & (1 << bit)) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.mm_i_format.simmediate << 1); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; } break; case mm_pool16c_op: switch (insn.mm_i_format.rt) { case mm_jalr16_op: case mm_jalrs16_op: regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; /* Fall through */ case mm_jr16_op: *contpc = regs->regs[insn.mm_i_format.rs]; return 1; } break; case mm_beqz16_op: if ((long)regs->regs[reg16to32map[insn.mm_b1_format.rs]] == 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.mm_b1_format.simmediate << 1); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case mm_bnez16_op: if ((long)regs->regs[reg16to32map[insn.mm_b1_format.rs]] != 0) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.mm_b1_format.simmediate << 1); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case mm_b16_op: *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.mm_b0_format.simmediate << 1); return 1; case mm_beq32_op: if (regs->regs[insn.mm_i_format.rs] == regs->regs[insn.mm_i_format.rt]) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.mm_i_format.simmediate << 1); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case mm_bne32_op: if (regs->regs[insn.mm_i_format.rs] != regs->regs[insn.mm_i_format.rt]) *contpc = regs->cp0_epc + dec_insn.pc_inc + (insn.mm_i_format.simmediate << 1); else *contpc = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; return 1; case mm_jalx32_op: regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; *contpc = regs->cp0_epc + dec_insn.pc_inc; *contpc >>= 28; *contpc <<= 28; *contpc |= (insn.j_format.target << 2); return 1; case mm_jals32_op: case mm_jal32_op: regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; /* Fall through */ case mm_j32_op: *contpc = regs->cp0_epc + dec_insn.pc_inc; *contpc >>= 27; *contpc <<= 27; *contpc |= (insn.j_format.target << 1); set_isa16_mode(*contpc); return 1; } 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: regs->regs[insn.r_format.rd] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; /* Fall through */ case jr_op: *contpc = regs->regs[insn.r_format.rs]; return 1; } break; case bcond_op: switch (insn.i_format.rt) { case bltzal_op: case bltzall_op: regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; /* Fall through */ case bltz_op: case bltzl_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: regs->regs[31] = regs->cp0_epc + dec_insn.pc_inc + dec_insn.next_pc_inc; /* Fall through */ case bgez_op: case bgezl_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 beq_op: case beql_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 bne_op: case bnel_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 blez_op: case blezl_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 bgtz_op: case bgtzl_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; #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; #endif case cop0_op: case cop1_op: case cop2_op: case cop1x_op: if (insn.i_format.rs == bc_op) { preempt_disable(); if (is_fpu_owner()) asm volatile("cfc1\t%0,$31" : "=r" (fcr31)); 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 defined(CONFIG_64BIT) && !defined(CONFIG_MIPS32_O32) return 1; #elif defined(CONFIG_32BIT) && !defined(CONFIG_MIPS_O32_FP64_SUPPORT) return 0; #else return !test_thread_flag(TIF_32BIT_FPREGS); #endif } #define SIFROMREG(si, x) do { \ if (cop1_64bit(xcp)) \ (si) = get_fpr32(&ctx->fpr[x], 0); \ else \ (si) = get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \ } while (0) #define SITOREG(si, x) do { \ if (cop1_64bit(xcp)) { \ 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) = 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) == 0)], 0)) #define DITOREG(di, x) do { \ unsigned fpr, i; \ fpr = (x) & ~(cop1_64bit(xcp) == 0); \ 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 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) { mips_instruction ir; unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc; unsigned int cond; int pc_inc; /* XXX NEC Vr54xx bug workaround */ if (xcp->cp0_cause & CAUSEF_BD) { if (dec_insn.micro_mips_mode) { if (!mm_isBranchInstr(xcp, dec_insn, &contpc)) xcp->cp0_cause &= ~CAUSEF_BD; } else { if (!isBranchInstr(xcp, dec_insn, &contpc)) 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. */ 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:{ u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); u64 val; 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_RT(ir)); break; } case sdc1_op:{ u64 __user *va = (u64 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); u64 val; MIPS_FPU_EMU_INC_STATS(stores); DIFROMREG(val, MIPSInst_RT(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 lwc1_op:{ u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); u32 val; 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_RT(ir)); break; } case swc1_op:{ u32 __user *va = (u32 __user *) (xcp->regs[MIPSInst_RS(ir)] + MIPSInst_SIMM(ir)); u32 val; MIPS_FPU_EMU_INC_STATS(stores); SIFROMREG(val, MIPSInst_RT(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 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 mfhc_op: if (!cpu_has_mips_r2) 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) 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] */ u32 value; if (MIPSInst_RD(ir) == FPCREG_CSR) { value = ctx->fcr31; value = (value & ~FPU_CSR_RM) | mips_rm[modeindex(value)]; #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 /* * Don't write reserved bits, * and convert to ieee library modes */ ctx->fcr31 = (value & ~(FPU_CSR_RSVD | FPU_CSR_RM)) | ieee_rm[modeindex(value)]; } 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 += 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. */ return mips_dsemul(xcp, ir, contpc); } } else contpc = (xcp->cp0_epc + (contpc << 2)); 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, contpc); } else { /* branch not taken */ if (likely) { /* * 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; { 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 = fpux_emu(xcp, ctx, ir, fault_addr); if (sig) 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: sigill: return SIGILL; } /* we did it !! */ xcp->cp0_epc = 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, void *__user *fault_addr) { unsigned rcsr = 0; /* resulting csr */ MIPS_FPU_EMU_INC_STATS(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)]); 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)) 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)]); 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; } #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 */ MIPS_FPU_EMU_INC_STATS(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[modeindex(MIPSInst_FUNC(ir))]; 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[modeindex(MIPSInst_FUNC(ir))]; 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[modeindex(MIPSInst_FUNC(ir))]; 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[modeindex(MIPSInst_FUNC(ir))]; 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:{ u64 bits; 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: 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, 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. 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, dec_insn, fault_addr); /* revert to mips rounding mode */ ieee754_csr.rm = mips_rm[ieee754_csr.rm]; } if (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; } #ifdef CONFIG_DEBUG_FS static int fpuemu_stat_get(void *data, u64 *val) { int cpu; unsigned long sum = 0; for_each_online_cpu(cpu) { struct mips_fpu_emulator_stats *ps; local_t *pv; ps = &per_cpu(fpuemustats, cpu); pv = (void *)ps + (unsigned long)data; sum += local_read(pv); } *val = sum; return 0; } DEFINE_SIMPLE_ATTRIBUTE(fops_fpuemu_stat, fpuemu_stat_get, NULL, "%llu\n"); extern struct dentry *mips_debugfs_dir; static int __init debugfs_fpuemu(void) { struct dentry *d, *dir; if (!mips_debugfs_dir) return -ENODEV; dir = debugfs_create_dir("fpuemustats", mips_debugfs_dir); if (!dir) return -ENOMEM; #define FPU_STAT_CREATE(M) \ do { \ d = debugfs_create_file(#M , S_IRUGO, dir, \ (void *)offsetof(struct mips_fpu_emulator_stats, M), \ &fops_fpuemu_stat); \ if (!d) \ return -ENOMEM; \ } while (0) FPU_STAT_CREATE(emulated); FPU_STAT_CREATE(loads); FPU_STAT_CREATE(stores); FPU_STAT_CREATE(cp1ops); FPU_STAT_CREATE(cp1xops); FPU_STAT_CREATE(errors); return 0; } __initcall(debugfs_fpuemu); #endif