/* $NetBSD: fpu.c,v 1.27 2012/02/12 16:34:10 matt Exp $ */ /* * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This software was developed by the Computer Systems Engineering group * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and * contributed to Berkeley. * * All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Lawrence Berkeley Laboratory. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)fpu.c 8.1 (Berkeley) 6/11/93 */ #include __KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.27 2012/02/12 16:34:10 matt Exp $"); #include #include #include #include #include #include #include #include #include #include int fpe_debug = 0; #ifdef DEBUG /* * Dump a `fpn' structure. */ void fpu_dumpfpn(struct fpn *fp) { static const char *class[] = { "SNAN", "QNAN", "ZERO", "NUM", "INF" }; printf("%s %c.%x %x %x %xE%d", class[fp->fp_class + 2], fp->fp_sign ? '-' : ' ', fp->fp_mant[0], fp->fp_mant[1], fp->fp_mant[2], fp->fp_mant[3], fp->fp_exp); } #endif /* * fpu_execute returns the following error numbers (0 = no error): */ #define FPE 1 /* take a floating point exception */ #define NOTFPU 2 /* not an FPU instruction */ /* * Translate current exceptions into `first' exception. The * bits go the wrong way for ffs() (0x10 is most important, etc). * There are only 5, so do it the obvious way. */ #define X1(x) x #define X2(x) x,x #define X4(x) x,x,x,x #define X8(x) X4(x),X4(x) #define X16(x) X8(x),X8(x) static char cx_to_trapx[] = { X1(FSR_NX), X2(FSR_DZ), X4(FSR_UF), X8(FSR_OF), X16(FSR_NV) }; static u_char fpu_codes_native[] = { X1(FPE_FLTRES), X2(FPE_FLTDIV), X4(FPE_FLTUND), X8(FPE_FLTOVF), X16(FPE_FLTINV) }; #if defined(COMPAT_SUNOS) static u_char fpu_codes_sunos[] = { X1(FPE_FLTINEX_TRAP), X2(FPE_FLTDIV_TRAP), X4(FPE_FLTUND_TRAP), X8(FPE_FLTOVF_TRAP), X16(FPE_FLTOPERR_TRAP) }; extern struct emul emul_sunos; #endif /* SUNOS_COMPAT */ /* Note: SVR4(Solaris) FPE_* codes happen to be compatible with ours */ /* * The FPU gave us an exception. Clean up the mess. Note that the * fp queue can only have FPops in it, never load/store FP registers * nor FBfcc instructions. Experiments with `crashme' prove that * unknown FPops do enter the queue, however. */ int fpu_cleanup( struct lwp *l, #ifndef SUN4U struct fpstate *fs #else /* SUN4U */ struct fpstate64 *fs #endif /* SUN4U */ ) { int i, fsr = fs->fs_fsr, error; struct proc *p = l->l_proc; union instr instr; struct fpemu fe; u_char *fpu_codes; int code = 0; fpu_codes = #ifdef COMPAT_SUNOS (p->p_emul == &emul_sunos) ? fpu_codes_sunos : #endif fpu_codes_native; switch ((fsr >> FSR_FTT_SHIFT) & FSR_FTT_MASK) { case FSR_TT_NONE: panic("fpu_cleanup: No fault"); /* ??? */ break; case FSR_TT_IEEE: DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_IEEE\n")); /* XXX missing trap address! */ if ((i = fsr & FSR_CX) == 0) panic("fpu ieee trap, but no exception"); code = fpu_codes[i - 1]; break; /* XXX should return, but queue remains */ case FSR_TT_UNFIN: DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_UNFIN\n")); #ifdef SUN4U if (fs->fs_qsize == 0) { printf("fpu_cleanup: unfinished fpop"); /* The book sez reexecute or emulate. */ return (0); } break; #endif /* SUN4U */ case FSR_TT_UNIMP: DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_UNIMP\n")); if (fs->fs_qsize == 0) panic("fpu_cleanup: unimplemented fpop"); break; case FSR_TT_SEQ: panic("fpu sequence error"); /* NOTREACHED */ case FSR_TT_HWERR: DPRINTF(FPE_INSN, ("fpu_cleanup: FSR_TT_HWERR\n")); log(LOG_ERR, "fpu hardware error (%s[%d])\n", p->p_comm, p->p_pid); uprintf("%s[%d]: fpu hardware error\n", p->p_comm, p->p_pid); code = SI_NOINFO; goto out; default: printf("fsr=0x%x\n", fsr); panic("fpu error"); } /* emulate the instructions left in the queue */ fe.fe_fpstate = fs; for (i = 0; i < fs->fs_qsize; i++) { instr.i_int = fs->fs_queue[i].fq_instr; if (instr.i_any.i_op != IOP_reg || (instr.i_op3.i_op3 != IOP3_FPop1 && instr.i_op3.i_op3 != IOP3_FPop2)) panic("bogus fpu queue"); error = fpu_execute(&fe, instr); if (error == 0) continue; switch (error) { case FPE: code = fpu_codes[(fs->fs_fsr & FSR_CX) - 1]; break; case NOTFPU: #ifdef SUN4U #ifdef DEBUG printf("fpu_cleanup: not an FPU error -- sending SIGILL\n"); #endif #endif /* SUN4U */ code = SI_NOINFO; break; default: panic("fpu_cleanup 3"); /* NOTREACHED */ } /* XXX should stop here, but queue remains */ } out: fs->fs_qsize = 0; return (code); } #ifdef notyet /* * If we have no FPU at all (are there any machines like this out * there!?) we have to emulate each instruction, and we need a pointer * to the trapframe so that we can step over them and do FBfcc's. * We know the `queue' is empty, though; we just want to emulate * the instruction at tf->tf_pc. */ fpu_emulate(l, tf, fs) struct lwp *l; struct trapframe *tf; #ifndef SUN4U struct fpstate *fs; #else /* SUN4U */ struct fpstate64 *fs; #endif /* SUN4U */ { do { fetch instr from pc decode if (integer instr) { struct pcb *pcb = lwp_getpcb(l); /* * We do this here, rather than earlier, to avoid * losing even more badly than usual. */ if (pcb->pcb_uw) { write_user_windows(); if (rwindow_save(l)) sigexit(l, SIGILL); } if (loadstore) { do_it; pc = npc, npc += 4 } else if (fbfcc) { do_annul_stuff; } else return; } else if (fpu instr) { fe.fe_fsr = fs->fs_fsr &= ~FSR_CX; error = fpu_execute(&fe, fs, instr); switch (error) { etc; } } else return; if (want to reschedule) return; } while (error == 0); } #endif /* * Execute an FPU instruction (one that runs entirely in the FPU; not * FBfcc or STF, for instance). On return, fe->fe_fs->fs_fsr will be * modified to reflect the setting the hardware would have left. * * Note that we do not catch all illegal opcodes, so you can, for instance, * multiply two integers this way. */ int fpu_execute(struct fpemu *fe, union instr instr) { struct fpn *fp; #ifndef SUN4U int opf, rs1, rs2, rd, type, mask, fsr, cx; struct fpstate *fs; #else /* SUN4U */ int opf, rs1, rs2, rd, type, mask, fsr, cx, i, cond; struct fpstate64 *fs; #endif /* SUN4U */ u_int space[4]; /* * `Decode' and execute instruction. Start with no exceptions. * The type of any i_opf opcode is in the bottom two bits, so we * squish them out here. */ opf = instr.i_opf.i_opf; /* * The low two bits of the opf field for floating point insns usually * correspond to the operation width: * * 0: Invalid * 1: Single precision float * 2: Double precision float * 3: Quad precision float * * The exceptions are the integer to float conversion instructions. * * For double and quad precision, the low bit if the rs or rd field * is actually the high bit of the register number. */ type = opf & 3; mask = 0x3 >> (3 - type); rs1 = instr.i_opf.i_rs1; rs1 = (rs1 & ~mask) | ((rs1 & mask & 0x1) << 5); rs2 = instr.i_opf.i_rs2; rs2 = (rs2 & ~mask) | ((rs2 & mask & 0x1) << 5); rd = instr.i_opf.i_rd; rd = (rd & ~mask) | ((rd & mask & 0x1) << 5); #ifdef DIAGNOSTIC if ((rs1 | rs2 | rd) & mask) /* This may be an FPU insn but it is illegal. */ return (NOTFPU); #endif fs = fe->fe_fpstate; fe->fe_fsr = fs->fs_fsr & ~FSR_CX; fe->fe_cx = 0; #ifdef SUN4U /* * Check to see if we're dealing with a fancy cmove and handle * it first. */ if (instr.i_op3.i_op3 == IOP3_FPop2 && (opf&0xff0) != (FCMP&0xff0)) { switch (opf >>= 2) { case FMVFC0 >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FMVFC0\n")); cond = (fs->fs_fsr>>FSR_FCC_SHIFT)&FSR_FCC_MASK; if (instr.i_fmovcc.i_cond != cond) return(0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVFC1 >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FMVFC1\n")); cond = (fs->fs_fsr>>FSR_FCC1_SHIFT)&FSR_FCC_MASK; if (instr.i_fmovcc.i_cond != cond) return(0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVFC2 >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FMVFC2\n")); cond = (fs->fs_fsr>>FSR_FCC2_SHIFT)&FSR_FCC_MASK; if (instr.i_fmovcc.i_cond != cond) return(0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVFC3 >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FMVFC3\n")); cond = (fs->fs_fsr>>FSR_FCC3_SHIFT)&FSR_FCC_MASK; if (instr.i_fmovcc.i_cond != cond) return(0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVIC >> 2: /* Presume we're curlwp */ DPRINTF(FPE_INSN, ("fpu_execute: FMVIC\n")); cond = (curlwp->l_md.md_tf->tf_tstate>>TSTATE_CCR_SHIFT)&PSR_ICC; if (instr.i_fmovcc.i_cond != cond) return(0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVXC >> 2: /* Presume we're curlwp */ DPRINTF(FPE_INSN, ("fpu_execute: FMVXC\n")); cond = (curlwp->l_md.md_tf->tf_tstate>>(TSTATE_CCR_SHIFT+XCC_SHIFT))&PSR_ICC; if (instr.i_fmovcc.i_cond != cond) return(0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVRZ >> 2: /* Presume we're curlwp */ DPRINTF(FPE_INSN, ("fpu_execute: FMVRZ\n")); rs1 = instr.i_fmovr.i_rs1; if (rs1 != 0 && (int64_t)curlwp->l_md.md_tf->tf_global[rs1] != 0) return (0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVRLEZ >> 2: /* Presume we're curlwp */ DPRINTF(FPE_INSN, ("fpu_execute: FMVRLEZ\n")); rs1 = instr.i_fmovr.i_rs1; if (rs1 != 0 && (int64_t)curlwp->l_md.md_tf->tf_global[rs1] > 0) return (0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVRLZ >> 2: /* Presume we're curlwp */ DPRINTF(FPE_INSN, ("fpu_execute: FMVRLZ\n")); rs1 = instr.i_fmovr.i_rs1; if (rs1 == 0 || (int64_t)curlwp->l_md.md_tf->tf_global[rs1] >= 0) return (0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVRNZ >> 2: /* Presume we're curlwp */ DPRINTF(FPE_INSN, ("fpu_execute: FMVRNZ\n")); rs1 = instr.i_fmovr.i_rs1; if (rs1 == 0 || (int64_t)curlwp->l_md.md_tf->tf_global[rs1] == 0) return (0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVRGZ >> 2: /* Presume we're curlwp */ DPRINTF(FPE_INSN, ("fpu_execute: FMVRGZ\n")); rs1 = instr.i_fmovr.i_rs1; if (rs1 == 0 || (int64_t)curlwp->l_md.md_tf->tf_global[rs1] <= 0) return (0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; case FMVRGEZ >> 2: /* Presume we're curlwp */ DPRINTF(FPE_INSN, ("fpu_execute: FMVRGEZ\n")); rs1 = instr.i_fmovr.i_rs1; if (rs1 != 0 && (int64_t)curlwp->l_md.md_tf->tf_global[rs1] < 0) return (0); /* success */ rs1 = fs->fs_regs[rs2]; goto mov; default: DPRINTF(FPE_INSN, ("fpu_execute: unknown v9 FP inst %x opf %x\n", instr.i_int, opf)); return (NOTFPU); } } #endif /* SUN4U */ switch (opf >>= 2) { default: DPRINTF(FPE_INSN, ("fpu_execute: unknown basic FP inst %x opf %x\n", instr.i_int, opf)); return (NOTFPU); case FMOV >> 2: /* these should all be pretty obvious */ DPRINTF(FPE_INSN, ("fpu_execute: FMOV\n")); rs1 = fs->fs_regs[rs2]; goto mov; case FNEG >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FNEG\n")); rs1 = fs->fs_regs[rs2] ^ (1 << 31); goto mov; case FABS >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FABS\n")); rs1 = fs->fs_regs[rs2] & ~(1 << 31); mov: #ifndef SUN4U fs->fs_regs[rd] = rs1; #else /* SUN4U */ i = 1<<(type-1); fs->fs_regs[rd++] = rs1; while (--i > 0) fs->fs_regs[rd++] = fs->fs_regs[++rs2]; #endif /* SUN4U */ fs->fs_fsr = fe->fe_fsr; return (0); /* success */ case FSQRT >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FSQRT\n")); fpu_explode(fe, &fe->fe_f1, type, rs2); fp = fpu_sqrt(fe); break; case FADD >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FADD\n")); fpu_explode(fe, &fe->fe_f1, type, rs1); fpu_explode(fe, &fe->fe_f2, type, rs2); fp = fpu_add(fe); break; case FSUB >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FSUB\n")); fpu_explode(fe, &fe->fe_f1, type, rs1); fpu_explode(fe, &fe->fe_f2, type, rs2); fp = fpu_sub(fe); break; case FMUL >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FMUL\n")); fpu_explode(fe, &fe->fe_f1, type, rs1); fpu_explode(fe, &fe->fe_f2, type, rs2); fp = fpu_mul(fe); break; case FDIV >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FDIV\n")); fpu_explode(fe, &fe->fe_f1, type, rs1); fpu_explode(fe, &fe->fe_f2, type, rs2); fp = fpu_div(fe); break; case FCMP >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FCMP\n")); fpu_explode(fe, &fe->fe_f1, type, rs1); fpu_explode(fe, &fe->fe_f2, type, rs2); fpu_compare(fe, 0); goto cmpdone; case FCMPE >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FCMPE\n")); fpu_explode(fe, &fe->fe_f1, type, rs1); fpu_explode(fe, &fe->fe_f2, type, rs2); fpu_compare(fe, 1); cmpdone: /* * The only possible exception here is NV; catch it * early and get out, as there is no result register. */ cx = fe->fe_cx; fsr = fe->fe_fsr | (cx << FSR_CX_SHIFT); if (cx != 0) { if (fsr & (FSR_NV << FSR_TEM_SHIFT)) { fs->fs_fsr = (fsr & ~FSR_FTT) | (FSR_TT_IEEE << FSR_FTT_SHIFT); return (FPE); } fsr |= FSR_NV << FSR_AX_SHIFT; } fs->fs_fsr = fsr; return (0); case FSMULD >> 2: case FDMULX >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FSMULx\n")); if (type == FTYPE_EXT) return (NOTFPU); fpu_explode(fe, &fe->fe_f1, type, rs1); fpu_explode(fe, &fe->fe_f2, type, rs2); type++; /* single to double, or double to quad */ fp = fpu_mul(fe); break; #ifdef SUN4U case FXTOS >> 2: case FXTOD >> 2: case FXTOQ >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FXTOx\n")); type = FTYPE_LNG; fpu_explode(fe, fp = &fe->fe_f1, type, rs2); type = opf & 3; /* sneaky; depends on instruction encoding */ break; case FTOX >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FTOX\n")); fpu_explode(fe, fp = &fe->fe_f1, type, rs2); type = FTYPE_LNG; /* Recalculate destination register */ rd = instr.i_opf.i_rd; break; #endif /* SUN4U */ case FTOI >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FTOI\n")); fpu_explode(fe, fp = &fe->fe_f1, type, rs2); type = FTYPE_INT; /* Recalculate destination register */ rd = instr.i_opf.i_rd; break; case FTOS >> 2: case FTOD >> 2: case FTOQ >> 2: DPRINTF(FPE_INSN, ("fpu_execute: FTOx\n")); fpu_explode(fe, fp = &fe->fe_f1, type, rs2); /* Recalculate rd with correct type info. */ type = opf & 3; /* sneaky; depends on instruction encoding */ mask = 0x3 >> (3 - type); rd = instr.i_opf.i_rd; rd = (rd & ~mask) | ((rd & mask & 0x1) << 5); break; } /* * ALU operation is complete. Collapse the result and then check * for exceptions. If we got any, and they are enabled, do not * alter the destination register, just stop with an exception. * Otherwise set new current exceptions and accrue. */ fpu_implode(fe, fp, type, space); cx = fe->fe_cx; fsr = fe->fe_fsr; if (cx != 0) { mask = (fsr >> FSR_TEM_SHIFT) & FSR_TEM_MASK; if (cx & mask) { /* not accrued??? */ fs->fs_fsr = (fsr & ~FSR_FTT) | (FSR_TT_IEEE << FSR_FTT_SHIFT) | (cx_to_trapx[(cx & mask) - 1] << FSR_CX_SHIFT); return (FPE); } fsr |= (cx << FSR_CX_SHIFT) | (cx << FSR_AX_SHIFT); } fs->fs_fsr = fsr; DPRINTF(FPE_REG, ("-> %c%d\n", (type == FTYPE_LNG) ? 'x' : ((type == FTYPE_INT) ? 'i' : ((type == FTYPE_SNG) ? 's' : ((type == FTYPE_DBL) ? 'd' : ((type == FTYPE_EXT) ? 'q' : '?')))), rd)); fs->fs_regs[rd] = space[0]; if (type >= FTYPE_DBL || type == FTYPE_LNG) { fs->fs_regs[rd + 1] = space[1]; if (type > FTYPE_DBL) { fs->fs_regs[rd + 2] = space[2]; fs->fs_regs[rd + 3] = space[3]; } } return (0); /* success */ }