include/ppc_asm.tmpl

/*
 * (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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

/*
 * 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


#if defined(CONFIG_8xx) || defined(CONFIG_MPC824X)

/* Some special registers */

#define ICR	148	/* Interrupt Cause Register (37-44) */
#define DER	149
#define COUNTA	150	/* Breakpoint Counter	    (37-44) */
#define COUNTB	151	/* Breakpoint Counter	    (37-44) */
#define LCTRL1	156	/* Load/Store Support	    (37-40) */
#define LCTRL2	157	/* Load/Store Support	    (37-41) */
#define ICTRL	158

#endif	/* CONFIG_8xx, CONFIG_MPC824X */

#if defined(CONFIG_8xx)

/* Registers in the processor's internal memory map that we use.
*/
#define SYPCR	0x00000004
#define BR0	0x00000100
#define OR0	0x00000104
#define BR1	0x00000108
#define OR1	0x0000010c
#define BR2	0x00000110
#define OR2	0x00000114
#define BR3	0x00000118
#define OR3	0x0000011c
#define BR4	0x00000120
#define OR4	0x00000124

#define MAR	0x00000164
#define MCR	0x00000168
#define MAMR	0x00000170
#define MBMR	0x00000174
#define MSTAT	0x00000178
#define MPTPR	0x0000017a
#define MDR	0x0000017c

#define TBSCR	0x00000200
#define TBREFF0	0x00000204

#define PLPRCR	0x00000284

#elif defined(CONFIG_8260)

#define HID2		1011

#define HID0_IFEM	(1<<7)

#define HID0_ICE_BITPOS	16
#define HID0_DCE_BITPOS	17

#define IM_REGBASE	0x10000
#define IM_SYPCR	(IM_REGBASE+0x0004)
#define IM_SWSR		(IM_REGBASE+0x000e)
#define IM_BR0		(IM_REGBASE+0x0100)
#define IM_OR0		(IM_REGBASE+0x0104)
#define IM_BR1		(IM_REGBASE+0x0108)
#define IM_OR1		(IM_REGBASE+0x010c)
#define IM_BR2		(IM_REGBASE+0x0110)
#define IM_OR2		(IM_REGBASE+0x0114)
#define IM_MPTPR	(IM_REGBASE+0x0184)
#define IM_PSDMR	(IM_REGBASE+0x0190)
#define IM_PSRT		(IM_REGBASE+0x019c)
#define IM_IMMR		(IM_REGBASE+0x01a8)
#define IM_SCCR		(IM_REGBASE+0x0c80)

#endif

#define curptr r2

#define SYNC \
	sync; \
	isync

/*
 * 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	\
	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	r22,SRR0;	\
	mfspr	r23,SRR1;	\
	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).
 */

/*
 * Critical exception entry code.  This is just like the other exception
 * code except that it uses SRR2 and SRR3 instead of SRR0 and SRR1.
 */
#define CRITICAL_EXCEPTION_PROLOG       \
        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   r22,990;        /* SRR2 */      \
        mfspr   r23,991;        /* SRR3 */      \
        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 (SRR2), and r23 (SRR3).
 */

/*
 * 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 STD_EXCEPTION(n, label, hdlr)			\
	. = n;						\
label:							\
	EXCEPTION_PROLOG;				\
	lwz	r3,GOT(transfer_to_handler);		\
	mtlr	r3;					\
	addi	r3,r1,STACK_FRAME_OVERHEAD;		\
	li	r20,MSR_KERNEL;				\
	rlwimi	r20,r23,0,25,25;			\
	blrl	; 					\
.L_ ## label :						\
	.long	hdlr - _start + EXC_OFF_SYS_RESET;	\
	.long	int_return - _start + EXC_OFF_SYS_RESET


#define CRIT_EXCEPTION(n, label, hdlr)                  \
        . = n;                                          \
label:                                                  \
        CRITICAL_EXCEPTION_PROLOG;                      \
        lwz     r3,GOT(transfer_to_handler);            \
        mtlr    r3;                                     \
        addi    r3,r1,STACK_FRAME_OVERHEAD;             \
        li      r20,MSR_KERNEL;                         \
        rlwimi  r20,r23,0,25,25;                        \
        blrl    ;                                       \
.L_ ## label :                                          \
        .long   hdlr - _start + EXC_OFF_SYS_RESET;      \
        .long   crit_return - _start + EXC_OFF_SYS_RESET

#endif	/* __PPC_ASM_TMPL__ */