root/lib/libc/arch/mips/gen/setjmp.S
/*      $NetBSD: setjmp.S,v 1.20 2020/10/15 05:27:53 skrll Exp $        */

/*-
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ralph Campbell.
 *
 * 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.
 */

#include <sys/syscall.h>
#include <mips/asm.h>

#include "assym.h"

#if defined(LIBC_SCCS) && !defined(lint)
#if 0
        RCSID("from: @(#)setjmp.s       8.1 (Berkeley) 6/4/93")
#else
        RCSID("$NetBSD: setjmp.S,v 1.20 2020/10/15 05:27:53 skrll Exp $")
#endif
#endif /* LIBC_SCCS and not lint */

/*
 * C library -- setjmp, longjmp
 *
 *      longjmp(a,v)
 * will generate a "return(v)" from
 * the last call to
 *      setjmp(a)
 * by restoring registers from the stack,
 * and a struct sigcontext, see <signal.h>
 */

#define SETJMP_FRAME_SIZE       (CALLFRAME_SIZ + STACK_T_SIZE)

NON_LEAF(__setjmp14, SETJMP_FRAME_SIZE, ra)
        .mask   0x80010000, (CALLFRAME_RA - CALLFRAME_SIZ)
        SETUP_GP
        PTR_SUBU        sp, sp, SETJMP_FRAME_SIZE       # allocate stack frame
        SAVE_GP(CALLFRAME_GP)
        SETUP_GP64(CALLFRAME_GP, __setjmp14)

        REG_S           ra, CALLFRAME_RA(sp)            # save RA
        REG_S           s0, CALLFRAME_S0(sp)            # save S0
        move            s0, a0                          # save sigcontext

        /* Get the signal mask. */
        PTR_ADDU        a2, a0, _SC_MASK                # &sc.sc_mask
        move            a1, zero
        jal             _C_LABEL(__sigprocmask14)       # get current signal mask

        /* Get the signal stack. */
        move            a0, zero
        PTR_ADDU        a1, sp, CALLFRAME_SIZ           # pointer to stack_t
        jal             _C_LABEL(__sigaltstack14)

        move            a0, s0                          # restore jmpbuf
        INT_L           v1, CALLFRAME_SIZ+_STACK_T_FLAGS(sp)
                                                        # get old ss_onstack
        and             v1, v1, SS_ONSTACK              # extract onstack flag
        INT_S           v1, _SC_ONSTACK(a0)             # save it in sc_onstack

        REG_L           s0, CALLFRAME_S0(sp)            # restore S0
        REG_L           ra, CALLFRAME_RA(sp)            # restore RA
        blt             v0, zero, botch                 # check for sigaltstack() error
        nop
        /*
         * We know we won't need this routine's GP anymore.
         */
        RESTORE_GP64
        PTR_ADDU        sp, sp, SETJMP_FRAME_SIZE       # pop stack frame


        REG_PROLOGUE
        REG_S   ra, _SC_PC(a0)                          # sc_pc = return address
        REG_LI  v0, 0xACEDBADE                          # sigcontext magic number
        REG_S   v0, _SC_REGS(a0)                        #   saved in sc_regs[0]
        REG_S   s0, _SC_REGS_S0(a0)
        REG_S   s1, _SC_REGS_S1(a0)
        REG_S   s2, _SC_REGS_S2(a0)
        REG_S   s3, _SC_REGS_S3(a0)
        REG_S   s4, _SC_REGS_S4(a0)
        REG_S   s5, _SC_REGS_S5(a0)
        REG_S   s6, _SC_REGS_S6(a0)
        REG_S   s7, _SC_REGS_S7(a0)
        REG_S   gp, _SC_REGS_GP(a0)
        REG_S   sp, _SC_REGS_SP(a0)
        REG_S   s8, _SC_REGS_S8(a0)
#ifdef SOFTFLOAT_FOR_GCC
        INT_S   zero, _SC_FPUSED(a0)                    # sc_fpused = 0
#else
        li      v0, 1                                   # be nice if we could tell
        INT_S   v0, _SC_FPUSED(a0)                      # sc_fpused = 1
        cfc1    v0, $31
        INT_S   v0, _SC_FPREGS_FCSR(a0)
#if defined(__mips_o32) || defined(__mips_o64) || defined(__mips_n32)
        FP_S    $f20, _SC_FPREGS_F20(a0)
        FP_S    $f22, _SC_FPREGS_F22(a0)
#endif
#if defined(__mips_o32) || defined(__mips_o64)
        FP_S    $f21, _SC_FPREGS_F21(a0)
        FP_S    $f23, _SC_FPREGS_F23(a0)
#endif
#if defined(__mips_n32) || defined(__mips_n64)
        FP_S    $f24, _SC_FPREGS_F24(a0)
        FP_S    $f26, _SC_FPREGS_F26(a0)
        FP_S    $f28, _SC_FPREGS_F28(a0)
        FP_S    $f30, _SC_FPREGS_F30(a0)
#endif
#if defined(__mips_n64)
        FP_S    $f25, _SC_FPREGS_F25(a0)
        FP_S    $f27, _SC_FPREGS_F27(a0)
        FP_S    $f29, _SC_FPREGS_F29(a0)
        FP_S    $f31, _SC_FPREGS_F31(a0)
#endif
#endif  /* SOFTFLOAT_FOR_GCC */
        REG_EPILOGUE
        move    v0, zero
        j       ra

botch:
        jal     _C_LABEL(abort)
END(__setjmp14)