/*
 * This file contains miscellaneous low-level functions.
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
 * and Paul Mackerras.
 * 
 * Rewrittten to work with /sbin/kexec 20 December 2004 Eric Biederman
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 */

#include "ppc_asm.h"	

/* This is from linux-2.6/arch/powerpc/lib/crtsavres.S:
 *
 * Special support for eabi and SVR4
 *
 *   Copyright (C) 1995, 1996, 1998, 2000, 2001 Free Software Foundation, Inc.
 *   Copyright 2008 Freescale Semiconductor, Inc.
 *   Written By Michael Meissner
 *
 * Based on gcc/config/rs6000/crtsavres.asm from gcc
 *
 * This file is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * In addition to the permissions in the GNU General Public License, the
 * Free Software Foundation gives you unlimited permission to link the
 * compiled version of this file with other programs, and to distribute
 * those programs without any restriction coming from the use of this
 * file.  (The General Public License restrictions do apply in other
 * respects; for example, they cover modification of the file, and
 * distribution when not linked into another program.)
 *
 * This file 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 *    As a special exception, if you link this library with files
 *    compiled with GCC to produce an executable, this does not cause
 *    the resulting executable to be covered by the GNU General Public License.
 *    This exception does not however invalidate any other reasons why
 *    the executable file might be covered by the GNU General Public License.
 */
#include "config.h"

#define _GLOBAL(name) \
	.type name,@function; \
	.globl name; \
name:

/* Routines for saving integer registers, called by the compiler.  */
/* Called with r11 pointing to the stack header word of the caller of the */
/* function, just beyond the end of the integer save area.  */

_GLOBAL(_savegpr_14)
_GLOBAL(_save32gpr_14)
	stw	14,-72(11)	/* save gp registers */
_GLOBAL(_savegpr_15)
_GLOBAL(_save32gpr_15)
	stw	15,-68(11)
_GLOBAL(_savegpr_16)
_GLOBAL(_save32gpr_16)
	stw	16,-64(11)
_GLOBAL(_savegpr_17)
_GLOBAL(_save32gpr_17)
	stw	17,-60(11)
_GLOBAL(_savegpr_18)
_GLOBAL(_save32gpr_18)
	stw	18,-56(11)
_GLOBAL(_savegpr_19)
_GLOBAL(_save32gpr_19)
	stw	19,-52(11)
_GLOBAL(_savegpr_20)
_GLOBAL(_save32gpr_20)
	stw	20,-48(11)
_GLOBAL(_savegpr_21)
_GLOBAL(_save32gpr_21)
	stw	21,-44(11)
_GLOBAL(_savegpr_22)
_GLOBAL(_save32gpr_22)
	stw	22,-40(11)
_GLOBAL(_savegpr_23)
_GLOBAL(_save32gpr_23)
	stw	23,-36(11)
_GLOBAL(_savegpr_24)
_GLOBAL(_save32gpr_24)
	stw	24,-32(11)
_GLOBAL(_savegpr_25)
_GLOBAL(_save32gpr_25)
	stw	25,-28(11)
_GLOBAL(_savegpr_26)
_GLOBAL(_save32gpr_26)
	stw	26,-24(11)
_GLOBAL(_savegpr_27)
_GLOBAL(_save32gpr_27)
	stw	27,-20(11)
_GLOBAL(_savegpr_28)
_GLOBAL(_save32gpr_28)
	stw	28,-16(11)
_GLOBAL(_savegpr_29)
_GLOBAL(_save32gpr_29)
	stw	29,-12(11)
_GLOBAL(_savegpr_30)
_GLOBAL(_save32gpr_30)
	stw	30,-8(11)
_GLOBAL(_savegpr_31)
_GLOBAL(_save32gpr_31)
	stw	31,-4(11)
	blr

/* Routines for restoring integer registers, called by the compiler.  */
/* Called with r11 pointing to the stack header word of the caller of the */
/* function, just beyond the end of the integer restore area.  */

_GLOBAL(_restgpr_14)
_GLOBAL(_rest32gpr_14)
	lwz	14,-72(11)	/* restore gp registers */
_GLOBAL(_restgpr_15)
_GLOBAL(_rest32gpr_15)
	lwz	15,-68(11)
_GLOBAL(_restgpr_16)
_GLOBAL(_rest32gpr_16)
	lwz	16,-64(11)
_GLOBAL(_restgpr_17)
_GLOBAL(_rest32gpr_17)
	lwz	17,-60(11)
_GLOBAL(_restgpr_18)
_GLOBAL(_rest32gpr_18)
	lwz	18,-56(11)
_GLOBAL(_restgpr_19)
_GLOBAL(_rest32gpr_19)
	lwz	19,-52(11)
_GLOBAL(_restgpr_20)
_GLOBAL(_rest32gpr_20)
	lwz	20,-48(11)
_GLOBAL(_restgpr_21)
_GLOBAL(_rest32gpr_21)
	lwz	21,-44(11)
_GLOBAL(_restgpr_22)
_GLOBAL(_rest32gpr_22)
	lwz	22,-40(11)
_GLOBAL(_restgpr_23)
_GLOBAL(_rest32gpr_23)
	lwz	23,-36(11)
_GLOBAL(_restgpr_24)
_GLOBAL(_rest32gpr_24)
	lwz	24,-32(11)
_GLOBAL(_restgpr_25)
_GLOBAL(_rest32gpr_25)
	lwz	25,-28(11)
_GLOBAL(_restgpr_26)
_GLOBAL(_rest32gpr_26)
	lwz	26,-24(11)
_GLOBAL(_restgpr_27)
_GLOBAL(_rest32gpr_27)
	lwz	27,-20(11)
_GLOBAL(_restgpr_28)
_GLOBAL(_rest32gpr_28)
	lwz	28,-16(11)
_GLOBAL(_restgpr_29)
_GLOBAL(_rest32gpr_29)
	lwz	29,-12(11)
_GLOBAL(_restgpr_30)
_GLOBAL(_rest32gpr_30)
	lwz	30,-8(11)
_GLOBAL(_restgpr_31)
_GLOBAL(_rest32gpr_31)
	lwz	31,-4(11)
	blr

/* Routines for restoring integer registers, called by the compiler.  */
/* Called with r11 pointing to the stack header word of the caller of the */
/* function, just beyond the end of the integer restore area.  */

_GLOBAL(_restgpr_14_x)
_GLOBAL(_rest32gpr_14_x)
	lwz	14,-72(11)	/* restore gp registers */
_GLOBAL(_restgpr_15_x)
_GLOBAL(_rest32gpr_15_x)
	lwz	15,-68(11)
_GLOBAL(_restgpr_16_x)
_GLOBAL(_rest32gpr_16_x)
	lwz	16,-64(11)
_GLOBAL(_restgpr_17_x)
_GLOBAL(_rest32gpr_17_x)
	lwz	17,-60(11)
_GLOBAL(_restgpr_18_x)
_GLOBAL(_rest32gpr_18_x)
	lwz	18,-56(11)
_GLOBAL(_restgpr_19_x)
_GLOBAL(_rest32gpr_19_x)
	lwz	19,-52(11)
_GLOBAL(_restgpr_20_x)
_GLOBAL(_rest32gpr_20_x)
	lwz	20,-48(11)
_GLOBAL(_restgpr_21_x)
_GLOBAL(_rest32gpr_21_x)
	lwz	21,-44(11)
_GLOBAL(_restgpr_22_x)
_GLOBAL(_rest32gpr_22_x)
	lwz	22,-40(11)
_GLOBAL(_restgpr_23_x)
_GLOBAL(_rest32gpr_23_x)
	lwz	23,-36(11)
_GLOBAL(_restgpr_24_x)
_GLOBAL(_rest32gpr_24_x)
	lwz	24,-32(11)
_GLOBAL(_restgpr_25_x)
_GLOBAL(_rest32gpr_25_x)
	lwz	25,-28(11)
_GLOBAL(_restgpr_26_x)
_GLOBAL(_rest32gpr_26_x)
	lwz	26,-24(11)
_GLOBAL(_restgpr_27_x)
_GLOBAL(_rest32gpr_27_x)
	lwz	27,-20(11)
_GLOBAL(_restgpr_28_x)
_GLOBAL(_rest32gpr_28_x)
	lwz	28,-16(11)
_GLOBAL(_restgpr_29_x)
_GLOBAL(_rest32gpr_29_x)
	lwz	29,-12(11)
_GLOBAL(_restgpr_30_x)
_GLOBAL(_rest32gpr_30_x)
	lwz	30,-8(11)
_GLOBAL(_restgpr_31_x)
_GLOBAL(_rest32gpr_31_x)
	lwz	0,4(11)
	lwz	31,-4(11)
	mtlr	0
	mr	1,11
	blr

	.text

/*
 * Extended precision shifts.
 *
 * Updated to be valid for shift counts from 0 to 63 inclusive.
 * -- Gabriel
 *
 * R3/R4 has 64 bit value
 * R5    has shift count
 * result in R3/R4
 *
 *  ashrdi3: arithmetic right shift (sign propagation)	
 *  lshrdi3: logical right shift
 *  ashldi3: left shift
 */
	.globl __ashrdi3
__ashrdi3:		
	subfic	r6,r5,32
	srw	r4,r4,r5	# LSW = count > 31 ? 0 : LSW >> count
	addi	r7,r5,32	# could be xori, or addi with -32
	slw	r6,r3,r6	# t1 = count > 31 ? 0 : MSW << (32-count)
	rlwinm	r8,r7,0,32	# t3 = (count < 32) ? 32 : 0
	sraw	r7,r3,r7	# t2 = MSW >> (count-32)
	or	r4,r4,r6	# LSW |= t1
	slw	r7,r7,r8	# t2 = (count < 32) ? 0 : t2
	sraw	r3,r3,r5	# MSW = MSW >> count
	or	r4,r4,r7	# LSW |= t2
	blr

	.globl __ashldi3
__ashldi3:	
	subfic	r6,r5,32
	slw	r3,r3,r5	# MSW = count > 31 ? 0 : MSW << count
	addi	r7,r5,32	# could be xori, or addi with -32
	srw	r6,r4,r6	# t1 = count > 31 ? 0 : LSW >> (32-count)
	slw	r7,r4,r7	# t2 = count < 32 ? 0 : LSW << (count-32)
	or	r3,r3,r6	# MSW |= t1
	slw	r4,r4,r5	# LSW = LSW << count
	or	r3,r3,r7	# MSW |= t2
	blr

	.globl __lshrdi3
__lshrdi3:	
	subfic	r6,r5,32
	srw	r4,r4,r5	# LSW = count > 31 ? 0 : LSW >> count
	addi	r7,r5,32	# could be xori, or addi with -32
	slw	r6,r3,r6	# t1 = count > 31 ? 0 : MSW << (32-count)
	srw	r7,r3,r7	# t2 = count < 32 ? 0 : MSW >> (count-32)
	or	r4,r4,r6	# LSW |= t1
	srw	r3,r3,r5	# MSW = MSW >> count
	or	r4,r4,r7	# LSW |= t2
	blr

