aboutsummaryrefslogtreecommitdiffstats
path: root/arch/ia64/include/asm/xen/minstate.h
blob: c57fa910f2c937e7473a9ea63e5ac9a7be74c86c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143

#ifdef CONFIG_VIRT_CPU_ACCOUNTING
/* read ar.itc in advance, and use it before leaving bank 0 */
#define XEN_ACCOUNT_GET_STAMP		\
	MOV_FROM_ITC(pUStk, p6, r20, r2);
#else
#define XEN_ACCOUNT_GET_STAMP
#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
 *	r31:	contains saved predicates (pr)
 *
 * Upon exit, the state is as follows:
 *	psr.ic: off
 *	 r2 = points to &pt_regs.r16
 *	 r8 = contents of ar.ccv
 *	 r9 = contents of ar.csd
 *	r10 = contents of ar.ssd
 *	r11 = FPSR_DEFAULT
 *	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, r14, r15:
 *		preserved
 * CONFIG_XEN note: p6/p7 are not 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 XEN_DO_SAVE_MIN(__COVER,SAVE_IFS,EXTRA,WORKAROUND)					\
	mov r16=IA64_KR(CURRENT);	/* M */							\
	mov r27=ar.rsc;			/* M */							\
	mov r20=r1;			/* A */							\
	mov r25=ar.unat;		/* M */							\
	MOV_FROM_IPSR(p0,r29);		/* M */							\
	MOV_FROM_IIP(r28);		/* M */							\
	mov r21=ar.fpsr;		/* M */							\
	mov r26=ar.pfs;			/* I */							\
	__COVER;			/* B;; (or nothing) */					\
	adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16;						\
	;;											\
	ld1 r17=[r16];				/* load current->thread.on_ustack flag */	\
	st1 [r16]=r0;				/* clear current->thread.on_ustack flag */	\
	adds r1=-IA64_TASK_THREAD_ON_USTACK_OFFSET,r16						\
	/* switch from user to kernel RBS: */							\
	;;											\
	invala;				/* M */							\
	/* SAVE_IFS;*/ /* see xen special handling below */					\
	cmp.eq pKStk,pUStk=r0,r17;		/* are we in kernel mode already? */		\
	;;											\
(pUStk)	mov ar.rsc=0;		/* set enforced lazy mode, pl 0, little-endian, loadrs=0 */	\
	;;											\
(pUStk)	mov.m r24=ar.rnat;									\
(pUStk)	addl r22=IA64_RBS_OFFSET,r1;			/* compute base of RBS */		\
(pKStk) mov r1=sp;					/* get sp  */				\
	;;											\
(pUStk) lfetch.fault.excl.nt1 [r22];								\
(pUStk)	addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r1;	/* compute base of memory stack */	\
(pUStk)	mov r23=ar.bspstore;				/* save ar.bspstore */			\
	;;											\
(pUStk)	mov ar.bspstore=r22;				/* switch to kernel RBS */		\
(pKStk) addl r1=-IA64_PT_REGS_SIZE,r1;			/* if in kernel mode, use sp (r12) */	\
	;;											\
(pUStk)	mov r18=ar.bsp;										\
(pUStk)	mov ar.rsc=0x3;		/* set eager mode, pl 0, little-endian, loadrs=0 */		\
	adds r17=2*L1_CACHE_BYTES,r1;		/* really: biggest cache-line size */		\
	adds r16=PT(CR_IPSR),r1;								\
	;;											\
	lfetch.fault.excl.nt1 [r17],L1_CACHE_BYTES;						\
	st8 [r16]=r29;		/* save cr.ipsr */						\
	;;											\
	lfetch.fault.excl.nt1 [r17];								\
	tbit.nz p15,p0=r29,IA64_PSR_I_BIT;							\
	mov r29=b0										\
	;;											\
	WORKAROUND;										\
	adds r16=PT(R8),r1;	/* initialize first base pointer */				\
	adds r17=PT(R9),r1;	/* initialize second base pointer */				\
(pKStk)	mov r18=r0;		/* make sure r18 isn't NaT */					\
	;;											\
.mem.offset 0,0; st8.spill [r16]=r8,16;								\
.mem.offset 8,0; st8.spill [r17]=r9,16;								\
        ;;											\
.mem.offset 0,0; st8.spill [r16]=r10,24;							\
	movl r8=XSI_PRECOVER_IFS;								\
.mem.offset 8,0; st8.spill [r17]=r11,24;							\
        ;;											\
	/* xen special handling for possibly lazy cover */					\
	/* SAVE_MIN case in dispatch_ia32_handler: mov r30=r0 */				\
	ld8 r30=[r8];										\
(pUStk)	sub r18=r18,r22;	/* r18=RSE.ndirty*8 */						\
	st8 [r16]=r28,16;	/* save cr.iip */						\
	;;											\
	st8 [r17]=r30,16;	/* save cr.ifs */						\
	mov r8=ar.ccv;										\
	mov r9=ar.csd;										\
	mov r10=ar.ssd;										\
	movl r11=FPSR_DEFAULT;   /* L-unit */							\
	;;											\
	st8 [r16]=r25,16;	/* save ar.unat */						\
	st8 [r17]=r26,16;	/* save ar.pfs */						\
	shl r18=r18,16;		/* compute ar.rsc to be used for "loadrs" */			\
	;;											\
	st8 [r16]=r27,16;	/* save ar.rsc */						\
(pUStk)	st8 [r17]=r24,16;	/* save ar.rnat */						\
(pKStk)	adds r17=16,r17;	/* skip over ar_rnat field */					\
	;;			/* avoid RAW on r16 & r17 */					\
(pUStk)	st8 [r16]=r23,16;	/* save ar.bspstore */						\
	st8 [r17]=r31,16;	/* save predicates */						\
(pKStk)	adds r16=16,r16;	/* skip over ar_bspstore field */				\
	;;											\
	st8 [r16]=r29,16;	/* save b0 */							\
	st8 [r17]=r18,16;	/* save ar.rsc value for "loadrs" */				\
	cmp.eq pNonSys,pSys=r0,r0	/* initialize pSys=0, pNonSys=1 */			\
	;;											\
.mem.offset 0,0; st8.spill [r16]=r20,16;	/* save original r1 */				\
.mem.offset 8,0; st8.spill [r17]=r12,16;							\
	adds r12=-16,r1;	/* switch to kernel memory stack (with 16 bytes of scratch) */	\
	;;											\
.mem.offset 0,0; st8.spill [r16]=r13,16;							\
.mem.offset 8,0; st8.spill [r17]=r21,16;	/* save ar.fpsr */				\
	mov r13=IA64_KR(CURRENT);	/* establish `current' */				\
	;;											\
.mem.offset 0,0; st8.spill [r16]=r15,16;							\
.mem.offset 8,0; st8.spill [r17]=r14,16;							\
	;;											\
.mem.offset 0,0; st8.spill [r16]=r2,16;								\
.mem.offset 8,0; st8.spill [r17]=r3,16;								\
	XEN_ACCOUNT_GET_STAMP									\
	adds r2=IA64_PT_REGS_R16_OFFSET,r1;							\
	;;											\
	EXTRA;											\
	movl r1=__gp;		/* establish kernel global pointer */				\
	;;											\
	ACCOUNT_SYS_ENTER									\
	BSW_1(r3,r14);	/* switch back to bank 1 (must be last in insn group) */		\
	;;