/* Copyright (C) 2001-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

     Contributed by David Mosberger-Tang <davidm@hpl.hp.com>.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

#include <features.h>

#include "ucontext_i.h"

/*  __setcontext (const ucontext_t *ucp)

  Restores the machine context in UCP and thereby resumes execution

  in that context.

  This implementation in intended to be used for *synchronous* context

  switches only.  Therefore, it does not have to restore anything

  other than the PRESERVED state.  */

ENTRY(__setcontext)

	.prologue

	.body

	alloc r11 = ar.pfs, 1, 0, 4, 0

	// sigprocmask (SIG_SETMASK, &sc->sc_mask, NULL):

	mov r3 = SC_MASK

	mov out0 = SIG_SETMASK

	;;

	add out1 = r3, in0

	mov out2 = 0

	mov out3 = 8	// sizeof kernel sigset_t

	invala

	DO_CALL(__NR_rt_sigprocmask)

	add r2 = SC_NAT, r32

	add r3 = SC_RNAT, r32			// r3 <- &sc_ar_rnat

	add rPOS = SC_GR, r32			// rPOS <- &sc_gr[0]

	;;

	ld8 rNAT = [r2], (SC_BSP-SC_NAT)

	extr.u rPOS = rPOS, 3, 6		// get NaT bit number for r0

	;;

	ld8 rBSP = [r2], (SC_UNAT-SC_BSP)

	ld8 rRNAT = [r3], (SC_FPSR-SC_RNAT)

	/*

	 * Rotate NaT bits by rPOS positions to the left:

	 */

	sub rCPOS = 64, rPOS

	;;

	ld8 rUNAT = [r2], (SC_PFS-SC_UNAT)

	ld8 rFPSR = [r3], (SC_LC-SC_FPSR)

	shl rTMP = rNAT, rPOS

	;;

	ld8 rPFS = [r2], (SC_PR-SC_PFS)

	ld8 rLC = [r3], (SC_BR+0*8-SC_LC)

	shr.u rNAT = rNAT, rCPOS

	;;

	ld8 rPR = [r2], (SC_BR+1*8-SC_PR)

	ld8 rB0 = [r3], 16

	or rNAT = rNAT, rTMP

	;;

	ld8 rB1 = [r2], 16

	ld8 rB2 = [r3], 16

	;;

	mov.m ar.unat = rNAT

	mov.m rRSC = ar.rsc

	;;

	ld8 rB3 = [r2], 16

	ld8 rB4 = [r3], (SC_GR+1*8-(SC_BR+4*8))

	;;

	ld8 rB5 = [r2], (SC_GR+4*8-(SC_BR+5*8))

	ld8.fill r1 = [r3], (5*8 - 1*8)

	;;

	ld8.fill r4 = [r2], 16

	ld8.fill r5 = [r3], 16

	mov b0 = rB0

	;;

	ld8.fill r6 = [r2], 48

	ld8.fill r7 = [r3], (SC_FR+2*16-(SC_GR+7*8))

	;;

	ld8.fill sp = [r2], (SC_FR+3*16-(SC_GR+12*8))

	mov.m ar.fpsr = rFPSR

	mov.i ar.pfs = rPFS

	;;

	ldf.fill f3 = [r2], 16

	ldf.fill f2 = [r3], 48

	mov b1 = rB1

	;;

	ldf.fill f4 = [r2], (16*16-4*16)

	ldf.fill f5 = [r3], (17*16-5*16)

	mov b2 = rB2

	;;

	ldf.fill f16 = [r2], 32

	ldf.fill f17 = [r3], 32

	mov b3 = rB3

	;;

	ldf.fill f18 = [r2], 32

	ldf.fill f19 = [r3], 32

	mov b4 = rB4

	;;

	ldf.fill f20 = [r2], 32

	ldf.fill f21 = [r3], 32

	mov b5 = rB5

	;;

	ldf.fill f22 = [r2], 32

	ldf.fill f23 = [r3], 32

	mov r8 = 0

	;;

	ldf.fill f24 = [r2], 32

	ldf.fill f25 = [r3], 32

	mov r9 = 0

	;;

	ldf.fill f26 = [r2], 32

	ldf.fill f27 = [r3], 32

	dep rTMP = 0, rRSC, 16, 14	// clear ar.rsc.loadrs

	;;

	ldf.fill f28 = [r2], 32

	ldf.fill f29 = [r3], 32

	and rTMP = ~0x3, rTMP		// clear ar.rsc.mode

	;;

	ldf.fill f30 = [r2], 32

	ldf.fill f31 = [r3], 32

	mov pr = rPR, -1

	;;

	mov.m ar.rsc = rTMP		// put RSE into enforced lazy mode

	;;

	loadrs				// drop dirty partition

	;;

	mov.m ar.bspstore = rBSP

	mov.m ar.unat = rUNAT

	mov.i ar.lc = rLC

	;;

	mov.m ar.rnat = rRNAT

	mov.m ar.rsc = rRSC

	ret

END(__setcontext)

weak_alias (__setcontext, setcontext)