summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/idle_power7.S
blob: dca6e16c2436d79c588e417ca5e012b145c76cfe (plain)
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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
/*
 *  This file contains the power_save function for Power7 CPUs.
 *
 *  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 <linux/threads.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/cputable.h>
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/ppc-opcode.h>
#include <asm/hw_irq.h>
#include <asm/kvm_book3s_asm.h>
#include <asm/opal.h>

#undef DEBUG

/* Idle state entry routines */

#define	IDLE_STATE_ENTER_SEQ(IDLE_INST)				\
	/* Magic NAP/SLEEP/WINKLE mode enter sequence */	\
	std	r0,0(r1);					\
	ptesync;						\
	ld	r0,0(r1);					\
1:	cmp	cr0,r0,r0;					\
	bne	1b;						\
	IDLE_INST;						\
	b	.

	.text

/*
 * Pass requested state in r3:
 * 	0 - nap
 * 	1 - sleep
 */
_GLOBAL(power7_powersave_common)
	/* Use r3 to pass state nap/sleep/winkle */
	/* NAP is a state loss, we create a regs frame on the
	 * stack, fill it up with the state we care about and
	 * stick a pointer to it in PACAR1. We really only
	 * need to save PC, some CR bits and the NV GPRs,
	 * but for now an interrupt frame will do.
	 */
	mflr	r0
	std	r0,16(r1)
	stdu	r1,-INT_FRAME_SIZE(r1)
	std	r0,_LINK(r1)
	std	r0,_NIP(r1)

#ifndef CONFIG_SMP
	/* Make sure FPU, VSX etc... are flushed as we may lose
	 * state when going to nap mode
	 */
	bl	discard_lazy_cpu_state
#endif /* CONFIG_SMP */

	/* Hard disable interrupts */
	mfmsr	r9
	rldicl	r9,r9,48,1
	rotldi	r9,r9,16
	mtmsrd	r9,1			/* hard-disable interrupts */

	/* Check if something happened while soft-disabled */
	lbz	r0,PACAIRQHAPPENED(r13)
	cmpwi	cr0,r0,0
	beq	1f
	addi	r1,r1,INT_FRAME_SIZE
	ld	r0,16(r1)
	mtlr	r0
	blr

1:	/* We mark irqs hard disabled as this is the state we'll
	 * be in when returning and we need to tell arch_local_irq_restore()
	 * about it
	 */
	li	r0,PACA_IRQ_HARD_DIS
	stb	r0,PACAIRQHAPPENED(r13)

	/* We haven't lost state ... yet */
	li	r0,0
	stb	r0,PACA_NAPSTATELOST(r13)

	/* Continue saving state */
	SAVE_GPR(2, r1)
	SAVE_NVGPRS(r1)
	mfcr	r4
	std	r4,_CCR(r1)
	std	r9,_MSR(r1)
	std	r1,PACAR1(r13)

_GLOBAL(power7_enter_nap_mode)
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
	/* Tell KVM we're napping */
	li	r4,KVM_HWTHREAD_IN_NAP
	stb	r4,HSTATE_HWTHREAD_STATE(r13)
#endif
	cmpwi	cr0,r3,1
	beq	2f
	IDLE_STATE_ENTER_SEQ(PPC_NAP)
	/* No return */
2:	IDLE_STATE_ENTER_SEQ(PPC_SLEEP)
	/* No return */

_GLOBAL(power7_idle)
	/* Now check if user or arch enabled NAP mode */
	LOAD_REG_ADDRBASE(r3,powersave_nap)
	lwz	r4,ADDROFF(powersave_nap)(r3)
	cmpwi	0,r4,0
	beqlr
	/* fall through */

_GLOBAL(power7_nap)
	li	r3,0
	b	power7_powersave_common
	/* No return */

_GLOBAL(power7_sleep)
	li	r3,1
	b	power7_powersave_common
	/* No return */

_GLOBAL(power7_wakeup_tb_loss)
	ld	r2,PACATOC(r13);
	ld	r1,PACAR1(r13)

	/* Time base re-sync */
	li	r0,OPAL_RESYNC_TIMEBASE
	LOAD_REG_ADDR(r11,opal);
	ld	r12,8(r11);
	ld	r2,0(r11);
	mtctr	r12
	bctrl

	/* TODO: Check r3 for failure */

	REST_NVGPRS(r1)
	REST_GPR(2, r1)
	ld	r3,_CCR(r1)
	ld	r4,_MSR(r1)
	ld	r5,_NIP(r1)
	addi	r1,r1,INT_FRAME_SIZE
	mtcr	r3
	mfspr	r3,SPRN_SRR1		/* Return SRR1 */
	mtspr	SPRN_SRR1,r4
	mtspr	SPRN_SRR0,r5
	rfid

_GLOBAL(power7_wakeup_loss)
	ld	r1,PACAR1(r13)
	REST_NVGPRS(r1)
	REST_GPR(2, r1)
	ld	r3,_CCR(r1)
	ld	r4,_MSR(r1)
	ld	r5,_NIP(r1)
	addi	r1,r1,INT_FRAME_SIZE
	mtcr	r3
	mtspr	SPRN_SRR1,r4
	mtspr	SPRN_SRR0,r5
	rfid

_GLOBAL(power7_wakeup_noloss)
	lbz	r0,PACA_NAPSTATELOST(r13)
	cmpwi	r0,0
	bne	power7_wakeup_loss
	ld	r1,PACAR1(r13)
	ld	r4,_MSR(r1)
	ld	r5,_NIP(r1)
	addi	r1,r1,INT_FRAME_SIZE
	mtspr	SPRN_SRR1,r4
	mtspr	SPRN_SRR0,r5
	rfid