/**
 * @file IA64minstate.h
 *
 * @remark Copy of source code from linux kernel
 * @remark linux/arch/ia64/kernel/minstate.h
 *
 */

#include <linux/config.h>

#include "IA64entry.h"

/*
 * A couple of convenience macros that make writing and reading
 * SAVE_MIN and SAVE_REST easier.
 */
#define rARPR		r31
#define rCRIFS		r30
#define rCRIPSR		r29
#define rCRIIP		r28
#define rARRSC		r27
#define rARPFS		r26
#define rARUNAT		r25
#define rARRNAT		r24
#define rARBSPSTORE	r23
#define rKRBS		r22
#define rB6		r21
#define rR1		r20

/*
 * Here start the source dependent macros.
 */

/*
 * For ivt.s we want to access the stack virtually so we dont have 
 * to disable translation on interrupts.
 */
#define MINSTATE_START_SAVE_MIN_VIRT					\
	/* r1 = current (virtual) */					\
	dep r1=-1, r1, 61, 3;						\
	/* set enforced lazy mode, pl 0, little-endian, loadrs=0 */	\
(pUser)	mov ar.rsc=0;							\
	;;								\
	/* compute base of RBS */					\
(pUser)	addl rKRBS=IA64_RBS_OFFSET, r1;					\
(pUser)	mov rARRNAT=ar.rnat;						\
	/* get sp  */							\
(pKern) mov r1=sp;							\
	;;								\
	/* compute base of memory stack */				\
(pUser)	addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE, r1;			\
	/* save ar.bspstore */						\
(pUser)	mov rARBSPSTORE=ar.bspstore;					\
	;;								\
	/* if in kernel mode, use sp (r12) */				\
(pKern) addl r1=-IA64_PT_REGS_SIZE, r1;					\
	/* switch to kernel RBS */					\
(pUser)	mov ar.bspstore=rKRBS;						\
	;;								\
(pUser)	mov r18=ar.bsp;							\
	/* set eager mode, pl 0, little-endian, loadrs=0 */		\
(pUser)	mov ar.rsc=0x3;

#define MINSTATE_END_SAVE_MIN_VIRT					\
	/* make `current' a kernel virtual address */			\
	or r13=r13, r14;						\
	/* switch back to bank 1 (must be last in insn group) */	\
	bsw.1;								\
	;;

/*
 * For mca_asm.S we want to access the stack physically since the state
 * is saved before we go virtual and dont want to destroy the iip or ipsr.
 */
#define MINSTATE_START_SAVE_MIN_PHYS					\
(pKern) movl sp=ia64_init_stack+IA64_STK_OFFSET-IA64_PT_REGS_SIZE;	\
	/* set enforced lazy mode, pl 0, little-endian, loadrs=0 */	\
(pUser)	mov ar.rsc=0;							\
	/* compute base of register backing store */			\
(pUser)	addl rKRBS=IA64_RBS_OFFSET, r1;					\
	;;								\
(pUser)	mov rARRNAT=ar.rnat;						\
	/* compute physical addr of sp	*/				\
(pKern) dep r1=0, sp, 61, 3;						\
	/* compute base of memory stack */				\
(pUser)	addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE, r1;			\
	/* save ar.bspstore */						\
(pUser)	mov rARBSPSTORE=ar.bspstore;					\
	/* compute kernel virtual addr of RBS */			\
(pUser)	dep rKRBS=-1, rKRBS, 61, 3;					\
	;;								\
	/* if in kernel mode, use sp (r12) */				\
(pKern) addl r1=-IA64_PT_REGS_SIZE, r1;					\
	/* switch to kernel RBS */					\
(pUser)	mov ar.bspstore=rKRBS;						\
	;;								\
(pUser)	mov r18=ar.bsp;							\
	/* set eager mode, pl 0, little-endian, loadrs=0 */		\
(pUser)	mov ar.rsc=0x3;

#define MINSTATE_END_SAVE_MIN_PHYS					\
	/* make sp a kernel virtual address */				\
	or r12=r12, r14;						\
	/* make `current' a kernel virtual address */			\
	or r13=r13, r14;						\
	;;

#ifdef MINSTATE_VIRT
# define MINSTATE_START_SAVE_MIN	MINSTATE_START_SAVE_MIN_VIRT
# define MINSTATE_END_SAVE_MIN		MINSTATE_END_SAVE_MIN_VIRT
#endif

#ifdef MINSTATE_PHYS
# define MINSTATE_START_SAVE_MIN	MINSTATE_START_SAVE_MIN_PHYS
# define MINSTATE_END_SAVE_MIN		MINSTATE_END_SAVE_MIN_PHYS
#endif

/*
 * DO_SAVE_MIN switches to the kernel stacks (if necessary) and saves
 * the minimum state necessary that allows us to turn psr.ic back
 * on.
 *
 * Assumed state upon entry:
 *	psr.ic: off
 *	psr.dt: off
 *	r31:	contains saved predicates (pr)
 *
 * Upon exit, the state is as follows:
 *	psr.ic: off
 *	r2 = points to &pt_regs.r16
 *	r12 = kernel sp (kernel virtual address)
 *	r13 = points to current task_struct (kernel virtual address)
 *	p15 = TRUE if psr.i is set in cr.ipsr
 *	predicate registers (other than p2, p3, and p15), b6, r3, r8, r9,
 *		r10, r11, r14, r15: preserved
 *
 * Note that psr.ic is NOT turned on by this macro.  This is so that
 * we can pass interruption state as arguments to a handler.
 */
#define DO_SAVE_MIN(COVER, SAVE_IFS, EXTRA)				\
	mov rARRSC=ar.rsc;						\
	mov rARPFS=ar.pfs;						\
	mov rR1=r1;							\
	mov rARUNAT=ar.unat;						\
	mov rCRIPSR=cr.ipsr;						\
	/* rB6 = branch reg 6 */			  		\
	mov rB6=b6;							\
	mov rCRIIP=cr.iip;						\
	/* r1 = current (physical) */			  		\
	mov r1=IA64_KR(CURRENT);					\
	COVER;								\
	;;								\
	invala;								\
	/* extract psr.cpl */				  		\
	extr.u r16=rCRIPSR, 32, 2;					\
	;;								\
	/* are we in kernel mode already? (psr.cpl==0) */ 		\
	cmp.eq pKern, pUser=r0, r16;					\
	/* switch from user to kernel RBS: */				\
	;;								\
	SAVE_IFS;							\
	MINSTATE_START_SAVE_MIN						\
	;;								\
	/* initialize first base pointer */	  			\
	mov r16=r1;							\
	/* initialize second base pointer */	  			\
	adds r17=8, r1;							\
	;;								\
	st8 [r16]=rCRIPSR, 16;	/* save cr.ipsr */			\
	st8 [r17]=rCRIIP, 16;	/* save cr.iip */			\
(pKern)	mov r18=r0;		/* make sure r18 isn't NaT */		\
	;;								\
	st8 [r16]=rCRIFS, 16;	/* save cr.ifs */			\
	st8 [r17]=rARUNAT, 16;	/* save ar.unat */			\
(pUser)	sub r18=r18, rKRBS;	/* r18=RSE.ndirty*8 */			\
	;;								\
	st8 [r16]=rARPFS, 16;	/* save ar.pfs */			\
	st8 [r17]=rARRSC, 16;	/* save ar.rsc */			\
	tbit.nz p15, p0=rCRIPSR, IA64_PSR_I_BIT				\
	;;			/* avoid RAW on r16 & r17 */		\
(pKern)	adds r16=16, r16;	/* skip over ar_rnat field */		\
(pKern)	adds r17=16, r17;	/* skip over ar_bspstore field */	\
(pUser)	st8 [r16]=rARRNAT, 16;	/* save ar.rnat */			\
(pUser)	st8 [r17]=rARBSPSTORE, 16;	/* save ar.bspstore */		\
	;;								\
	st8 [r16]=rARPR, 16;	/* save predicates */			\
	st8 [r17]=rB6, 16;	/* save b6 */				\
	/* compute ar.rsc to be used for "loadrs" */			\
	shl r18=r18, 16;						\
	;;								\
	st8 [r16]=r18, 16;	/* save ar.rsc value for "loadrs" */	\
	st8.spill [r17]=rR1, 16;	/* save original r1 */		\
	;;								\
.mem.offset 0, 0;	st8.spill [r16]=r2, 16;				\
.mem.offset 8, 0;	st8.spill [r17]=r3, 16;				\
	adds r2=IA64_PT_REGS_R16_OFFSET, r1;				\
	;;								\
.mem.offset 0, 0;		st8.spill [r16]=r12, 16;		\
.mem.offset 8, 0;		st8.spill [r17]=r13, 16;		\
	/* initialize pSys=0, pNonSys=1 */			  	\
	cmp.eq pNonSys, pSys=r0, r0					\
	;;								\
.mem.offset 0, 0;		st8.spill [r16]=r14, 16;		\
.mem.offset 8, 0;		st8.spill [r17]=r15, 16;		\
	dep r14=-1, r0, 61, 3;						\
	;;								\
.mem.offset 0, 0;		st8.spill [r16]=r8, 16;			\
.mem.offset 8, 0;		st8.spill [r17]=r9, 16;			\
	/* switch to kernel memory stack (with 16 bytes of scratch) */	\
	adds r12=-16, r1;						\
	;;								\
.mem.offset 0, 0;		st8.spill [r16]=r10, 16;		\
.mem.offset 8, 0;		st8.spill [r17]=r11, 16;		\
	mov r13=IA64_KR(CURRENT);	/* establish `current' */	\
	;;								\
	EXTRA;								\
	movl r1=__gp;		/* establish kernel global pointer */	\
	;;								\
	MINSTATE_END_SAVE_MIN

/*
 * SAVE_REST saves the remainder of pt_regs (with psr.ic on).  This
 * macro guarantees to preserve all predicate registers, r8, r9, r10,
 * r11, r14, and r15.
 *
 * Assumed state upon entry:
 *	psr.ic: on
 *	psr.dt: on
 *	r2:	points to &pt_regs.r16
 *	r3:	points to &pt_regs.r17
 */
#define SAVE_REST				\
.mem.offset 0, 0;	st8.spill [r2]=r16, 16;	\
.mem.offset 8, 0;	st8.spill [r3]=r17, 16;	\
	;;					\
.mem.offset 0, 0;	st8.spill [r2]=r18, 16;	\
.mem.offset 8, 0;	st8.spill [r3]=r19, 16;	\
	;;					\
	mov r16=ar.ccv;		/* M-unit */	\
	movl r18=FPSR_DEFAULT	/* L-unit */	\
	;;					\
	mov r17=ar.fpsr;	/* M-unit */	\
	mov ar.fpsr=r18;	/* M-unit */	\
	;;					\
.mem.offset 0, 0;	st8.spill [r2]=r20, 16;	\
.mem.offset 8, 0;	st8.spill [r3]=r21, 16;	\
	mov r18=b0;				\
	;;					\
.mem.offset 0, 0;	st8.spill [r2]=r22, 16;	\
.mem.offset 8, 0;	st8.spill [r3]=r23, 16;	\
	mov r19=b7;				\
	;;					\
.mem.offset 0, 0;	st8.spill [r2]=r24, 16;	\
.mem.offset 8, 0;	st8.spill [r3]=r25, 16;	\
	;;					\
.mem.offset 0, 0;	st8.spill [r2]=r26, 16;	\
.mem.offset 8, 0;	st8.spill [r3]=r27, 16;	\
	;;					\
.mem.offset 0, 0;	st8.spill [r2]=r28, 16;	\
.mem.offset 8, 0;	st8.spill [r3]=r29, 16;	\
	;;					\
.mem.offset 0, 0;	st8.spill [r2]=r30, 16;	\
.mem.offset 8, 0;	st8.spill [r3]=r31, 16;	\
	;;					\
	st8 [r2]=r16, 16;	/* ar.ccv */	\
	st8 [r3]=r17, 16;	/* ar.fpsr */	\
	;;					\
	st8 [r2]=r18, 16;	/* b0 */	\
	st8 [r3]=r19, 16+8;	/* b7 */	\
	;;					\
	stf.spill [r2]=f6, 32;			\
	stf.spill [r3]=f7, 32;			\
	;;					\
	stf.spill [r2]=f8, 32;			\
	stf.spill [r3]=f9, 32

#define SAVE_MIN_WITH_COVER	DO_SAVE_MIN(cover, mov rCRIFS=cr.ifs,)
#define SAVE_MIN_WITH_COVER_R19	\
	DO_SAVE_MIN(cover, mov rCRIFS=cr.ifs, mov r15=r19)
#define SAVE_MIN		DO_SAVE_MIN(, mov rCRIFS=r0,)