/*
 * (C) Copyright 2000-2002
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program 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.
 *
 */

/*
 * This file contains all the macros and symbols which define
 * a PowerPC assembly language environment.
 */
#ifndef	__PPC_ASM_TMPL__
#define __PPC_ASM_TMPL__

/*
 * These definitions simplify the ugly declarations necessary for GOT
 * definitions.
 *
 * Stolen from prepboot/bootldr.h, (C) 1998 Gabriel Paubert, paubert@iram.es
 *
 * Uses r14 to access the GOT
 */

#define START_GOT			\
	.section	".got2","aw";	\
.LCTOC1 = .+32768

#define END_GOT				\
	.text

#define GET_GOT				\
	bl	1f		;	\
	.text	2		;	\
0:	.long	.LCTOC1-1f	;	\
	.text			;	\
1:	mflr	r14		;	\
	lwz	r0,0b-1b(r14)	;	\
	add	r14,r0,r14	;

#define GOT_ENTRY(NAME)		.L_ ## NAME = . - .LCTOC1 ; .long NAME

#define GOT(NAME)		.L_ ## NAME (r14)

/* Register names */
#define	r0	0
#define	r1	1
#define	r2	2
#define	r3	3
#define	r4	4
#define	r5	5
#define	r6	6
#define	r7	7
#define	r8	8
#define	r9	9
#define	r10	10
#define	r11	11
#define	r12	12
#define	r13	13
#define	r14	14
#define	r15	15
#define	r16	16
#define	r17	17
#define	r18	18
#define	r19	19
#define	r20	20
#define	r21	21
#define	r22	22
#define	r23	23
#define	r24	24
#define	r25	25
#define	r26	26
#define	r27	27
#define	r28	28
#define	r29	29
#define	r30	30
#define	r31	31

#define curptr r2

#define SYNC \
	sync; \
	isync

#if defined(CONFIG_MPC5xxx) || defined(CONFIG_MPC8220)

#define HID0_ICE_BITPOS 16
#define HID0_DCE_BITPOS 17

#endif
/*
 * Macros for storing registers into and loading registers from
 * exception frames.
 */
#define SAVE_GPR(n, base)	stw	n,GPR0+4*(n)(base)
#define SAVE_2GPRS(n, base)	SAVE_GPR(n, base); SAVE_GPR(n+1, base)
#define SAVE_4GPRS(n, base)	SAVE_2GPRS(n, base); SAVE_2GPRS(n+2, base)
#define SAVE_8GPRS(n, base)	SAVE_4GPRS(n, base); SAVE_4GPRS(n+4, base)
#define SAVE_10GPRS(n, base)	SAVE_8GPRS(n, base); SAVE_2GPRS(n+8, base)
#define REST_GPR(n, base)	lwz	n,GPR0+4*(n)(base)
#define REST_2GPRS(n, base)	REST_GPR(n, base); REST_GPR(n+1, base)
#define REST_4GPRS(n, base)	REST_2GPRS(n, base); REST_2GPRS(n+2, base)
#define REST_8GPRS(n, base)	REST_4GPRS(n, base); REST_4GPRS(n+4, base)
#define REST_10GPRS(n, base)	REST_8GPRS(n, base); REST_2GPRS(n+8, base)

/*
 * GCC sometimes accesses words at negative offsets from the stack
 * pointer, although the SysV ABI says it shouldn't.  To cope with
 * this, we leave this much untouched space on the stack on exception
 * entry.
 */
#define STACK_UNDERHEAD	64

/*
 * Exception entry code.  This code runs with address translation
 * turned off, i.e. using physical addresses.
 * We assume sprg3 has the physical address of the current
 * task's thread_struct.
 */
#define EXCEPTION_PROLOG(reg1, reg2)	\
	mtspr	SPRG0,r20;	\
	mtspr	SPRG1,r21;	\
	mfcr	r20;		\
	subi	r21,r1,INT_FRAME_SIZE+STACK_UNDERHEAD;	/* alloc exc. frame */\
	stw	r20,_CCR(r21);		/* save registers */ \
	stw	r22,GPR22(r21);	\
	stw	r23,GPR23(r21);	\
	mfspr	r20,SPRG0;	\
	stw	r20,GPR20(r21);	\
	mfspr	r22,SPRG1;	\
	stw	r22,GPR21(r21);	\
	mflr	r20;		\
	stw	r20,_LINK(r21);	\
	mfctr	r22;		\
	stw	r22,_CTR(r21);	\
	mfspr	r20,XER;	\
	stw	r20,_XER(r21);	\
	mfspr	r20, DAR_DEAR;	\
	stw	r20,_DAR(r21);	\
	mfspr	r22,reg1;	\
	mfspr	r23,reg2;	\
	stw	r0,GPR0(r21);	\
	stw	r1,GPR1(r21);	\
	stw	r2,GPR2(r21);	\
	stw	r1,0(r21);	\
	mr	r1,r21;			/* set new kernel sp */	\
	SAVE_4GPRS(3, r21);
/*
 * Note: code which follows this uses cr0.eq (set if from kernel),
 * r21, r22 (SRR0), and r23 (SRR1).
 */

/*
 * Exception vectors.
 *
 * The data words for `hdlr' and `int_return' are initialized with
 * OFFSET values only; they must be relocated first before they can
 * be used!
 */
#define COPY_EE(d, s)		rlwimi d,s,0,16,16
#define NOCOPY(d, s)
#define EXC_XFER_TEMPLATE(label, hdlr, msr, copyee)	\
	bl	1f;					\
1:	mflr    r20;					\
	lwz	r20,(.L_ ## label)-1b+8(r20);		\
	mtlr	r20;					\
	li	r20,msr;				\
	copyee(r20,r23);				\
	rlwimi	r20,r23,0,25,25;			\
	blrl;						\
.L_ ## label :						\
	.long	hdlr - _start + _START_OFFSET;		\
	.long	int_return - _start + _START_OFFSET;	\
	.long	transfer_to_handler - _start + _START_OFFSET

#define STD_EXCEPTION(n, label, hdlr)				\
	. = n;							\
label:								\
	EXCEPTION_PROLOG(SRR0, SRR1);				\
	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
	EXC_XFER_TEMPLATE(label, hdlr, MSR_KERNEL, NOCOPY)	\

#define CRIT_EXCEPTION(n, label, hdlr)				\
	. = n;							\
label:								\
	EXCEPTION_PROLOG(CSRR0, CSRR1);				\
	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
	EXC_XFER_TEMPLATE(label, hdlr,				\
	MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE), NOCOPY)		\

#define MCK_EXCEPTION(n, label, hdlr)				\
	. = n;							\
label:								\
	EXCEPTION_PROLOG(MCSRR0, MCSRR1);			\
	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
	EXC_XFER_TEMPLATE(label, hdlr,				\
	MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE), NOCOPY)		\

#endif	/* __PPC_ASM_TMPL__ */