cregit-Linux how code gets into the kernel

Release 4.14 arch/sparc/math-emu/math_64.c

// SPDX-License-Identifier: GPL-2.0
/*
 * arch/sparc64/math-emu/math.c
 *
 * Copyright (C) 1997,1999 Jakub Jelinek (jj@ultra.linux.cz)
 * Copyright (C) 1999 David S. Miller (davem@redhat.com)
 *
 * Emulation routines originate from soft-fp package, which is part
 * of glibc and has appropriate copyrights in it.
 */

#include <linux/types.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/perf_event.h>

#include <asm/fpumacro.h>
#include <asm/ptrace.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>

#include "sfp-util_64.h"
#include <math-emu/soft-fp.h>
#include <math-emu/single.h>
#include <math-emu/double.h>
#include <math-emu/quad.h>

/* QUAD - ftt == 3 */

#define FMOVQ	0x003

#define FNEGQ	0x007

#define FABSQ	0x00b

#define FSQRTQ	0x02b

#define FADDQ	0x043

#define FSUBQ	0x047

#define FMULQ	0x04b

#define FDIVQ	0x04f

#define FDMULQ	0x06e

#define FQTOX	0x083

#define FXTOQ	0x08c

#define FQTOS	0x0c7

#define FQTOD	0x0cb

#define FITOQ	0x0cc

#define FSTOQ	0x0cd

#define FDTOQ	0x0ce

#define FQTOI	0x0d3
/* SUBNORMAL - ftt == 2 */

#define FSQRTS	0x029

#define FSQRTD	0x02a

#define FADDS	0x041

#define FADDD	0x042

#define FSUBS	0x045

#define FSUBD	0x046

#define FMULS	0x049

#define FMULD	0x04a

#define FDIVS	0x04d

#define FDIVD	0x04e

#define FSMULD	0x069

#define FSTOX	0x081

#define FDTOX	0x082

#define FDTOS	0x0c6

#define FSTOD	0x0c9

#define FSTOI	0x0d1

#define FDTOI	0x0d2

#define FXTOS	0x084 
/* Only Ultra-III generates this. */

#define FXTOD	0x088 
/* Only Ultra-III generates this. */
#if 0	/* Optimized inline in sparc64/kernel/entry.S */
#define FITOS	0x0c4 /* Only Ultra-III generates this. */
#endif

#define FITOD	0x0c8 
/* Only Ultra-III generates this. */
/* FPOP2 */

#define FCMPQ	0x053

#define FCMPEQ	0x057

#define FMOVQ0	0x003

#define FMOVQ1	0x043

#define FMOVQ2	0x083

#define FMOVQ3	0x0c3

#define FMOVQI	0x103

#define FMOVQX	0x183

#define FMOVQZ	0x027

#define FMOVQLE	0x047

#define FMOVQLZ 0x067

#define FMOVQNZ	0x0a7

#define FMOVQGZ	0x0c7

#define FMOVQGE 0x0e7


#define FSR_TEM_SHIFT	23UL

#define FSR_TEM_MASK	(0x1fUL << FSR_TEM_SHIFT)

#define FSR_AEXC_SHIFT	5UL

#define FSR_AEXC_MASK	(0x1fUL << FSR_AEXC_SHIFT)

#define FSR_CEXC_SHIFT	0UL

#define FSR_CEXC_MASK	(0x1fUL << FSR_CEXC_SHIFT)

/* All routines returning an exception to raise should detect
 * such exceptions _before_ rounding to be consistent with
 * the behavior of the hardware in the implemented cases
 * (and thus with the recommendations in the V9 architecture
 * manual).
 *
 * We return 0 if a SIGFPE should be sent, 1 otherwise.
 */

static inline int record_exception(struct pt_regs *regs, int eflag) { u64 fsr = current_thread_info()->xfsr[0]; int would_trap; /* Determine if this exception would have generated a trap. */ would_trap = (fsr & ((long)eflag << FSR_TEM_SHIFT)) != 0UL; /* If trapping, we only want to signal one bit. */ if(would_trap != 0) { eflag &= ((fsr & FSR_TEM_MASK) >> FSR_TEM_SHIFT); if((eflag & (eflag - 1)) != 0) { if(eflag & FP_EX_INVALID) eflag = FP_EX_INVALID; else if(eflag & FP_EX_OVERFLOW) eflag = FP_EX_OVERFLOW; else if(eflag & FP_EX_UNDERFLOW) eflag = FP_EX_UNDERFLOW; else if(eflag & FP_EX_DIVZERO) eflag = FP_EX_DIVZERO; else if(eflag & FP_EX_INEXACT) eflag = FP_EX_INEXACT; } } /* Set CEXC, here is the rule: * * In general all FPU ops will set one and only one * bit in the CEXC field, this is always the case * when the IEEE exception trap is enabled in TEM. */ fsr &= ~(FSR_CEXC_MASK); fsr |= ((long)eflag << FSR_CEXC_SHIFT); /* Set the AEXC field, rule is: * * If a trap would not be generated, the * CEXC just generated is OR'd into the * existing value of AEXC. */ if(would_trap == 0) fsr |= ((long)eflag << FSR_AEXC_SHIFT); /* If trapping, indicate fault trap type IEEE. */ if(would_trap != 0) fsr |= (1UL << 14); current_thread_info()->xfsr[0] = fsr; /* If we will not trap, advance the program counter over * the instruction being handled. */ if(would_trap == 0) { regs->tpc = regs->tnpc; regs->tnpc += 4; } return (would_trap ? 0 : 1); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)22898.28%375.00%
David S. Miller41.72%125.00%
Total232100.00%4100.00%

typedef union { u32 s; u64 d; u64 q[2]; } *argp;
int do_mathemu(struct pt_regs *regs, struct fpustate *f, bool illegal_insn_trap) { unsigned long pc = regs->tpc; unsigned long tstate = regs->tstate; u32 insn = 0; int type = 0; /* ftt tells which ftt it may happen in, r is rd, b is rs2 and a is rs1. The *u arg tells whether the argument should be packed/unpacked (0 - do not unpack/pack, 1 - unpack/pack) non-u args tells the size of the argument (0 - no argument, 1 - single, 2 - double, 3 - quad */ #define TYPE(ftt, r, ru, b, bu, a, au) type = (au << 2) | (a << 0) | (bu << 5) | (b << 3) | (ru << 8) | (r << 6) | (ftt << 9) int freg; static u64 zero[2] = { 0L, 0L }; int flags; FP_DECL_EX; FP_DECL_S(SA); FP_DECL_S(SB); FP_DECL_S(SR); FP_DECL_D(DA); FP_DECL_D(DB); FP_DECL_D(DR); FP_DECL_Q(QA); FP_DECL_Q(QB); FP_DECL_Q(QR); int IR; long XR, xfsr; if (tstate & TSTATE_PRIV) die_if_kernel("unfinished/unimplemented FPop from kernel", regs); perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0); if (test_thread_flag(TIF_32BIT)) pc = (u32)pc; if (get_user(insn, (u32 __user *) pc) != -EFAULT) { if ((insn & 0xc1f80000) == 0x81a00000) /* FPOP1 */ { switch ((insn >> 5) & 0x1ff) { /* QUAD - ftt == 3 */ case FMOVQ: case FNEGQ: case FABSQ: TYPE(3,3,0,3,0,0,0); break; case FSQRTQ: TYPE(3,3,1,3,1,0,0); break; case FADDQ: case FSUBQ: case FMULQ: case FDIVQ: TYPE(3,3,1,3,1,3,1); break; case FDMULQ: TYPE(3,3,1,2,1,2,1); break; case FQTOX: TYPE(3,2,0,3,1,0,0); break; case FXTOQ: TYPE(3,3,1,2,0,0,0); break; case FQTOS: TYPE(3,1,1,3,1,0,0); break; case FQTOD: TYPE(3,2,1,3,1,0,0); break; case FITOQ: TYPE(3,3,1,1,0,0,0); break; case FSTOQ: TYPE(3,3,1,1,1,0,0); break; case FDTOQ: TYPE(3,3,1,2,1,0,0); break; case FQTOI: TYPE(3,1,0,3,1,0,0); break; /* We can get either unimplemented or unfinished * for these cases. Pre-Niagara systems generate * unfinished fpop for SUBNORMAL cases, and Niagara * always gives unimplemented fpop for fsqrt{s,d}. */ case FSQRTS: { unsigned long x = current_thread_info()->xfsr[0]; x = (x >> 14) & 0x7; TYPE(x,1,1,1,1,0,0); break; } case FSQRTD: { unsigned long x = current_thread_info()->xfsr[0]; x = (x >> 14) & 0x7; TYPE(x,2,1,2,1,0,0); break; } /* SUBNORMAL - ftt == 2 */ case FADDD: case FSUBD: case FMULD: case FDIVD: TYPE(2,2,1,2,1,2,1); break; case FADDS: case FSUBS: case FMULS: case FDIVS: TYPE(2,1,1,1,1,1,1); break; case FSMULD: TYPE(2,2,1,1,1,1,1); break; case FSTOX: TYPE(2,2,0,1,1,0,0); break; case FDTOX: TYPE(2,2,0,2,1,0,0); break; case FDTOS: TYPE(2,1,1,2,1,0,0); break; case FSTOD: TYPE(2,2,1,1,1,0,0); break; case FSTOI: TYPE(2,1,0,1,1,0,0); break; case FDTOI: TYPE(2,1,0,2,1,0,0); break; /* Only Ultra-III generates these */ case FXTOS: TYPE(2,1,1,2,0,0,0); break; case FXTOD: TYPE(2,2,1,2,0,0,0); break; #if 0 /* Optimized inline in sparc64/kernel/entry.S */ case FITOS: TYPE(2,1,1,1,0,0,0); break; #endif case FITOD: TYPE(2,2,1,1,0,0,0); break; } } else if ((insn & 0xc1f80000) == 0x81a80000) /* FPOP2 */ { IR = 2; switch ((insn >> 5) & 0x1ff) { case FCMPQ: TYPE(3,0,0,3,1,3,1); break; case FCMPEQ: TYPE(3,0,0,3,1,3,1); break; /* Now the conditional fmovq support */ case FMOVQ0: case FMOVQ1: case FMOVQ2: case FMOVQ3: /* fmovq %fccX, %fY, %fZ */ if (!((insn >> 11) & 3)) XR = current_thread_info()->xfsr[0] >> 10; else XR = current_thread_info()->xfsr[0] >> (30 + ((insn >> 10) & 0x6)); XR &= 3; IR = 0; switch ((insn >> 14) & 0x7) { /* case 0: IR = 0; break; */ /* Never */ case 1: if (XR) IR = 1; break; /* Not Equal */ case 2: if (XR == 1 || XR == 2) IR = 1; break; /* Less or Greater */ case 3: if (XR & 1) IR = 1; break; /* Unordered or Less */ case 4: if (XR == 1) IR = 1; break; /* Less */ case 5: if (XR & 2) IR = 1; break; /* Unordered or Greater */ case 6: if (XR == 2) IR = 1; break; /* Greater */ case 7: if (XR == 3) IR = 1; break; /* Unordered */ } if ((insn >> 14) & 8) IR ^= 1; break; case FMOVQI: case FMOVQX: /* fmovq %[ix]cc, %fY, %fZ */ XR = regs->tstate >> 32; if ((insn >> 5) & 0x80) XR >>= 4; XR &= 0xf; IR = 0; freg = ((XR >> 2) ^ XR) & 2; switch ((insn >> 14) & 0x7) { /* case 0: IR = 0; break; */ /* Never */ case 1: if (XR & 4) IR = 1; break; /* Equal */ case 2: if ((XR & 4) || freg) IR = 1; break; /* Less or Equal */ case 3: if (freg) IR = 1; break; /* Less */ case 4: if (XR & 5) IR = 1; break; /* Less or Equal Unsigned */ case 5: if (XR & 1) IR = 1; break; /* Carry Set */ case 6: if (XR & 8) IR = 1; break; /* Negative */ case 7: if (XR & 2) IR = 1; break; /* Overflow Set */ } if ((insn >> 14) & 8) IR ^= 1; break; case FMOVQZ: case FMOVQLE: case FMOVQLZ: case FMOVQNZ: case FMOVQGZ: case FMOVQGE: freg = (insn >> 14) & 0x1f; if (!freg) XR = 0; else if (freg < 16) XR = regs->u_regs[freg]; else if (!test_thread_64bit_stack(regs->u_regs[UREG_FP])) { struct reg_window32 __user *win32; flushw_user (); win32 = (struct reg_window32 __user *)((unsigned long)((u32)regs->u_regs[UREG_FP])); get_user(XR, &win32->locals[freg - 16]); } else { struct reg_window __user *win; flushw_user (); win = (struct reg_window __user *)(regs->u_regs[UREG_FP] + STACK_BIAS); get_user(XR, &win->locals[freg - 16]); } IR = 0; switch ((insn >> 10) & 3) { case 1: if (!XR) IR = 1; break; /* Register Zero */ case 2: if (XR <= 0) IR = 1; break; /* Register Less Than or Equal to Zero */ case 3: if (XR < 0) IR = 1; break; /* Register Less Than Zero */ } if ((insn >> 10) & 4) IR ^= 1; break; } if (IR == 0) { /* The fmov test was false. Do a nop instead */ current_thread_info()->xfsr[0] &= ~(FSR_CEXC_MASK); regs->tpc = regs->tnpc; regs->tnpc += 4; return 1; } else if (IR == 1) { /* Change the instruction into plain fmovq */ insn = (insn & 0x3e00001f) | 0x81a00060; TYPE(3,3,0,3,0,0,0); } } } if (type) { argp rs1 = NULL, rs2 = NULL, rd = NULL; /* Starting with UltraSPARC-T2, the cpu does not set the FP Trap * Type field in the %fsr to unimplemented_FPop. Nor does it * use the fp_exception_other trap. Instead it signals an * illegal instruction and leaves the FP trap type field of * the %fsr unchanged. */ if (!illegal_insn_trap) { int ftt = (current_thread_info()->xfsr[0] >> 14) & 0x7; if (ftt != (type >> 9)) goto err; } current_thread_info()->xfsr[0] &= ~0x1c000; freg = ((insn >> 14) & 0x1f); switch (type & 0x3) { case 3: if (freg & 2) { current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */; goto err; } case 2: freg = ((freg & 1) << 5) | (freg & 0x1e); case 1: rs1 = (argp)&f->regs[freg]; flags = (freg < 32) ? FPRS_DL : FPRS_DU; if (!(current_thread_info()->fpsaved[0] & flags)) rs1 = (argp)&zero; break; } switch (type & 0x7) { case 7: FP_UNPACK_QP (QA, rs1); break; case 6: FP_UNPACK_DP (DA, rs1); break; case 5: FP_UNPACK_SP (SA, rs1); break; } freg = (insn & 0x1f); switch ((type >> 3) & 0x3) { case 3: if (freg & 2) { current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */; goto err; } case 2: freg = ((freg & 1) << 5) | (freg & 0x1e); case 1: rs2 = (argp)&f->regs[freg]; flags = (freg < 32) ? FPRS_DL : FPRS_DU; if (!(current_thread_info()->fpsaved[0] & flags)) rs2 = (argp)&zero; break; } switch ((type >> 3) & 0x7) { case 7: FP_UNPACK_QP (QB, rs2); break; case 6: FP_UNPACK_DP (DB, rs2); break; case 5: FP_UNPACK_SP (SB, rs2); break; } freg = ((insn >> 25) & 0x1f); switch ((type >> 6) & 0x3) { case 3: if (freg & 2) { current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */; goto err; } case 2: freg = ((freg & 1) << 5) | (freg & 0x1e); case 1: rd = (argp)&f->regs[freg]; flags = (freg < 32) ? FPRS_DL : FPRS_DU; if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) { current_thread_info()->fpsaved[0] = FPRS_FEF; current_thread_info()->gsr[0] = 0; } if (!(current_thread_info()->fpsaved[0] & flags)) { if (freg < 32) memset(f->regs, 0, 32*sizeof(u32)); else memset(f->regs+32, 0, 32*sizeof(u32)); } current_thread_info()->fpsaved[0] |= flags; break; } switch ((insn >> 5) & 0x1ff) { /* + */ case FADDS: FP_ADD_S (SR, SA, SB); break; case FADDD: FP_ADD_D (DR, DA, DB); break; case FADDQ: FP_ADD_Q (QR, QA, QB); break; /* - */ case FSUBS: FP_SUB_S (SR, SA, SB); break; case FSUBD: FP_SUB_D (DR, DA, DB); break; case FSUBQ: FP_SUB_Q (QR, QA, QB); break; /* * */ case FMULS: FP_MUL_S (SR, SA, SB); break; case FSMULD: FP_CONV (D, S, 1, 1, DA, SA); FP_CONV (D, S, 1, 1, DB, SB); case FMULD: FP_MUL_D (DR, DA, DB); break; case FDMULQ: FP_CONV (Q, D, 2, 1, QA, DA); FP_CONV (Q, D, 2, 1, QB, DB); case FMULQ: FP_MUL_Q (QR, QA, QB); break; /* / */ case FDIVS: FP_DIV_S (SR, SA, SB); break; case FDIVD: FP_DIV_D (DR, DA, DB); break; case FDIVQ: FP_DIV_Q (QR, QA, QB); break; /* sqrt */ case FSQRTS: FP_SQRT_S (SR, SB); break; case FSQRTD: FP_SQRT_D (DR, DB); break; case FSQRTQ: FP_SQRT_Q (QR, QB); break; /* mov */ case FMOVQ: rd->q[0] = rs2->q[0]; rd->q[1] = rs2->q[1]; break; case FABSQ: rd->q[0] = rs2->q[0] & 0x7fffffffffffffffUL; rd->q[1] = rs2->q[1]; break; case FNEGQ: rd->q[0] = rs2->q[0] ^ 0x8000000000000000UL; rd->q[1] = rs2->q[1]; break; /* float to int */ case FSTOI: FP_TO_INT_S (IR, SB, 32, 1); break; case FDTOI: FP_TO_INT_D (IR, DB, 32, 1); break; case FQTOI: FP_TO_INT_Q (IR, QB, 32, 1); break; case FSTOX: FP_TO_INT_S (XR, SB, 64, 1); break; case FDTOX: FP_TO_INT_D (XR, DB, 64, 1); break; case FQTOX: FP_TO_INT_Q (XR, QB, 64, 1); break; /* int to float */ case FITOQ: IR = rs2->s; FP_FROM_INT_Q (QR, IR, 32, int); break; case FXTOQ: XR = rs2->d; FP_FROM_INT_Q (QR, XR, 64, long); break; /* Only Ultra-III generates these */ case FXTOS: XR = rs2->d; FP_FROM_INT_S (SR, XR, 64, long); break; case FXTOD: XR = rs2->d; FP_FROM_INT_D (DR, XR, 64, long); break; #if 0 /* Optimized inline in sparc64/kernel/entry.S */ case FITOS: IR = rs2->s; FP_FROM_INT_S (SR, IR, 32, int); break; #endif case FITOD: IR = rs2->s; FP_FROM_INT_D (DR, IR, 32, int); break; /* float to float */ case FSTOD: FP_CONV (D, S, 1, 1, DR, SB); break; case FSTOQ: FP_CONV (Q, S, 2, 1, QR, SB); break; case FDTOQ: FP_CONV (Q, D, 2, 1, QR, DB); break; case FDTOS: FP_CONV (S, D, 1, 1, SR, DB); break; case FQTOS: FP_CONV (S, Q, 1, 2, SR, QB); break; case FQTOD: FP_CONV (D, Q, 1, 2, DR, QB); break; /* comparison */ case FCMPQ: case FCMPEQ: FP_CMP_Q(XR, QB, QA, 3); if (XR == 3 && (((insn >> 5) & 0x1ff) == FCMPEQ || FP_ISSIGNAN_Q(QA) || FP_ISSIGNAN_Q(QB))) FP_SET_EXCEPTION (FP_EX_INVALID); } if (!FP_INHIBIT_RESULTS) { switch ((type >> 6) & 0x7) { case 0: xfsr = current_thread_info()->xfsr[0]; if (XR == -1) XR = 2; switch (freg & 3) { /* fcc0, 1, 2, 3 */ case 0: xfsr &= ~0xc00; xfsr |= (XR << 10); break; case 1: xfsr &= ~0x300000000UL; xfsr |= (XR << 32); break; case 2: xfsr &= ~0xc00000000UL; xfsr |= (XR << 34); break; case 3: xfsr &= ~0x3000000000UL; xfsr |= (XR << 36); break; } current_thread_info()->xfsr[0] = xfsr; break; case 1: rd->s = IR; break; case 2: rd->d = XR; break; case 5: FP_PACK_SP (rd, SR); break; case 6: FP_PACK_DP (rd, DR); break; case 7: FP_PACK_QP (rd, QR); break; } } if(_fex != 0) return record_exception(regs, _fex); /* Success and no exceptions detected. */ current_thread_info()->xfsr[0] &= ~(FSR_CEXC_MASK); regs->tpc = regs->tnpc; regs->tnpc += 4; return 1; } err: return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)294491.23%433.33%
David S. Miller2838.77%866.67%
Total3227100.00%12100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)343891.31%628.57%
David S. Miller3198.47%942.86%
David Howells30.08%14.76%
Greg Kroah-Hartman10.03%14.76%
Sam Ravnborg10.03%14.76%
Steven Cole10.03%14.76%
Linus Torvalds10.03%14.76%
Adrian Bunk10.03%14.76%
Total3765100.00%21100.00%
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