1/*
2 * S390 64-bit swsusp implementation
3 *
4 * Copyright IBM Corp. 2009
5 *
6 * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
7 *	      Michael Holzheu <holzheu@linux.vnet.ibm.com>
8 */
9
10#include <linux/linkage.h>
11#include <asm/page.h>
12#include <asm/ptrace.h>
13#include <asm/thread_info.h>
14#include <asm/asm-offsets.h>
15
16/*
17 * Save register context in absolute 0 lowcore and call swsusp_save() to
18 * create in-memory kernel image. The context is saved in the designated
19 * "store status" memory locations (see POP).
20 * We return from this function twice. The first time during the suspend to
21 * disk process. The second time via the swsusp_arch_resume() function
22 * (see below) in the resume process.
23 * This function runs with disabled interrupts.
24 */
25	.section .text
26ENTRY(swsusp_arch_suspend)
27	stmg	%r6,%r15,__SF_GPRS(%r15)
28	lgr	%r1,%r15
29	aghi	%r15,-STACK_FRAME_OVERHEAD
30	stg	%r1,__SF_BACKCHAIN(%r15)
31
32	/* Deactivate DAT */
33	stnsm	__SF_EMPTY(%r15),0xfb
34
35	/* Store prefix register on stack */
36	stpx	__SF_EMPTY(%r15)
37
38	/* Save prefix register contents for lowcore */
39	llgf	%r4,__SF_EMPTY(%r15)
40
41	/* Get pointer to save area */
42	lghi	%r1,0x1000
43
44	/* Save CPU address */
45	stap	__LC_EXT_CPU_ADDR(%r0)
46
47	/* Store registers */
48	mvc	0x318(4,%r1),__SF_EMPTY(%r15)	/* move prefix to lowcore */
49	stfpc	0x31c(%r1)			/* store fpu control */
50	std	0,0x200(%r1)			/* store f0 */
51	std	1,0x208(%r1)			/* store f1 */
52	std	2,0x210(%r1)			/* store f2 */
53	std	3,0x218(%r1)			/* store f3 */
54	std	4,0x220(%r1)			/* store f4 */
55	std	5,0x228(%r1)			/* store f5 */
56	std	6,0x230(%r1)			/* store f6 */
57	std	7,0x238(%r1)			/* store f7 */
58	std	8,0x240(%r1)			/* store f8 */
59	std	9,0x248(%r1)			/* store f9 */
60	std	10,0x250(%r1)			/* store f10 */
61	std	11,0x258(%r1)			/* store f11 */
62	std	12,0x260(%r1)			/* store f12 */
63	std	13,0x268(%r1)			/* store f13 */
64	std	14,0x270(%r1)			/* store f14 */
65	std	15,0x278(%r1)			/* store f15 */
66	stam	%a0,%a15,0x340(%r1)		/* store access registers */
67	stctg	%c0,%c15,0x380(%r1)		/* store control registers */
68	stmg	%r0,%r15,0x280(%r1)		/* store general registers */
69
70	stpt	0x328(%r1)			/* store timer */
71	stck	__SF_EMPTY(%r15)		/* store clock */
72	stckc	0x330(%r1)			/* store clock comparator */
73
74	/* Update cputime accounting before going to sleep */
75	lg	%r0,__LC_LAST_UPDATE_TIMER
76	slg	%r0,0x328(%r1)
77	alg	%r0,__LC_SYSTEM_TIMER
78	stg	%r0,__LC_SYSTEM_TIMER
79	mvc	__LC_LAST_UPDATE_TIMER(8),0x328(%r1)
80	lg	%r0,__LC_LAST_UPDATE_CLOCK
81	slg	%r0,__SF_EMPTY(%r15)
82	alg	%r0,__LC_STEAL_TIMER
83	stg	%r0,__LC_STEAL_TIMER
84	mvc	__LC_LAST_UPDATE_CLOCK(8),__SF_EMPTY(%r15)
85
86	/* Activate DAT */
87	stosm	__SF_EMPTY(%r15),0x04
88
89	/* Set prefix page to zero */
90	xc	__SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
91	spx	__SF_EMPTY(%r15)
92
93	lghi	%r2,0
94	lghi	%r3,2*PAGE_SIZE
95	lghi	%r5,2*PAGE_SIZE
961:	mvcle	%r2,%r4,0
97	jo	1b
98
99	/* Save image */
100	brasl	%r14,swsusp_save
101
102	/* Restore prefix register and return */
103	lghi	%r1,0x1000
104	spx	0x318(%r1)
105	lmg	%r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
106	lghi	%r2,0
107	br	%r14
108
109/*
110 * Restore saved memory image to correct place and restore register context.
111 * Then we return to the function that called swsusp_arch_suspend().
112 * swsusp_arch_resume() runs with disabled interrupts.
113 */
114ENTRY(swsusp_arch_resume)
115	stmg	%r6,%r15,__SF_GPRS(%r15)
116	lgr	%r1,%r15
117	aghi	%r15,-STACK_FRAME_OVERHEAD
118	stg	%r1,__SF_BACKCHAIN(%r15)
119
120	/* Make all free pages stable */
121	lghi	%r2,1
122	brasl	%r14,arch_set_page_states
123
124	/* Deactivate DAT */
125	stnsm	__SF_EMPTY(%r15),0xfb
126
127	/* Set prefix page to zero */
128	xc	__SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
129	spx	__SF_EMPTY(%r15)
130
131	/* Restore saved image */
132	larl	%r1,restore_pblist
133	lg	%r1,0(%r1)
134	ltgr	%r1,%r1
135	jz	2f
1360:
137	lg	%r2,8(%r1)
138	lg	%r4,0(%r1)
139	iske	%r0,%r4
140	lghi	%r3,PAGE_SIZE
141	lghi	%r5,PAGE_SIZE
1421:
143	mvcle	%r2,%r4,0
144	jo	1b
145	lg	%r2,8(%r1)
146	sske	%r0,%r2
147	lg	%r1,16(%r1)
148	ltgr	%r1,%r1
149	jnz	0b
1502:
151	ptlb				/* flush tlb */
152
153	/* Reset System */
154	larl	%r1,restart_entry
155	larl	%r2,.Lrestart_diag308_psw
156	og	%r1,0(%r2)
157	stg	%r1,0(%r0)
158	larl	%r1,.Lnew_pgm_check_psw
159	epsw	%r2,%r3
160	stm	%r2,%r3,0(%r1)
161	mvc	__LC_PGM_NEW_PSW(16,%r0),0(%r1)
162	lghi	%r0,0
163	diag	%r0,%r0,0x308
164restart_entry:
165	lhi	%r1,1
166	sigp	%r1,%r0,0x12
167	sam64
168	larl	%r1,.Lnew_pgm_check_psw
169	lpswe	0(%r1)
170pgm_check_entry:
171
172	/* Switch to original suspend CPU */
173	larl	%r1,.Lresume_cpu		/* Resume CPU address: r2 */
174	stap	0(%r1)
175	llgh	%r2,0(%r1)
176	llgh	%r1,__LC_EXT_CPU_ADDR(%r0)	/* Suspend CPU address: r1 */
177	cgr	%r1,%r2
178	je	restore_registers		/* r1 = r2 -> nothing to do */
179	larl	%r4,.Lrestart_suspend_psw	/* Set new restart PSW */
180	mvc	__LC_RST_NEW_PSW(16,%r0),0(%r4)
1813:
182	sigp	%r9,%r1,11			/* sigp initial cpu reset */
183	brc	8,4f				/* accepted */
184	brc	2,3b				/* busy, try again */
185
186	/* Suspend CPU not available -> panic */
187	larl	%r15,init_thread_union
188	ahi	%r15,1<<(PAGE_SHIFT+THREAD_ORDER)
189	larl	%r2,.Lpanic_string
190	larl	%r3,_sclp_print_early
191	lghi	%r1,0
192	sam31
193	sigp	%r1,%r0,0x12
194	basr	%r14,%r3
195	larl	%r3,.Ldisabled_wait_31
196	lpsw	0(%r3)
1974:
198	/* Switch to suspend CPU */
199	sigp	%r9,%r1,6		/* sigp restart to suspend CPU */
200	brc	2,4b			/* busy, try again */
2015:
202	sigp	%r9,%r2,5		/* sigp stop to current resume CPU */
203	brc	2,5b			/* busy, try again */
2046:	j	6b
205
206restart_suspend:
207	larl	%r1,.Lresume_cpu
208	llgh	%r2,0(%r1)
2097:
210	sigp	%r9,%r2,1		/* sigp sense, wait for resume CPU */
211	brc	8,7b			/* accepted, status 0, still running */
212	brc	2,7b			/* busy, try again */
213	tmll	%r9,0x40		/* Test if resume CPU is stopped */
214	jz	7b
215
216restore_registers:
217	/* Restore registers */
218	lghi	%r13,0x1000		/* %r1 = pointer to save area */
219
220	/* Ignore time spent in suspended state. */
221	llgf	%r1,0x318(%r13)
222	stck	__LC_LAST_UPDATE_CLOCK(%r1)
223	spt	0x328(%r13)		/* reprogram timer */
224	//sckc	0x330(%r13)		/* set clock comparator */
225
226	lctlg	%c0,%c15,0x380(%r13)	/* load control registers */
227	lam	%a0,%a15,0x340(%r13)	/* load access registers */
228
229	lfpc	0x31c(%r13)		/* load fpu control */
230	ld	0,0x200(%r13)		/* load f0 */
231	ld	1,0x208(%r13)		/* load f1 */
232	ld	2,0x210(%r13)		/* load f2 */
233	ld	3,0x218(%r13)		/* load f3 */
234	ld	4,0x220(%r13)		/* load f4 */
235	ld	5,0x228(%r13)		/* load f5 */
236	ld	6,0x230(%r13)		/* load f6 */
237	ld	7,0x238(%r13)		/* load f7 */
238	ld	8,0x240(%r13)		/* load f8 */
239	ld	9,0x248(%r13)		/* load f9 */
240	ld	10,0x250(%r13)		/* load f10 */
241	ld	11,0x258(%r13)		/* load f11 */
242	ld	12,0x260(%r13)		/* load f12 */
243	ld	13,0x268(%r13)		/* load f13 */
244	ld	14,0x270(%r13)		/* load f14 */
245	ld	15,0x278(%r13)		/* load f15 */
246
247	/* Load old stack */
248	lg	%r15,0x2f8(%r13)
249
250	/* Restore prefix register */
251	spx	0x318(%r13)
252
253	/* Activate DAT */
254	stosm	__SF_EMPTY(%r15),0x04
255
256	/* Make all free pages unstable */
257	lghi	%r2,0
258	brasl	%r14,arch_set_page_states
259
260	/* Log potential guest relocation */
261	brasl	%r14,lgr_info_log
262
263	/* Reinitialize the channel subsystem */
264	brasl	%r14,channel_subsystem_reinit
265
266	/* Return 0 */
267	lmg	%r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
268	lghi	%r2,0
269	br	%r14
270
271	.section .data..nosave,"aw",@progbits
272	.align	8
273.Ldisabled_wait_31:
274	.long  0x000a0000,0x00000000
275.Lpanic_string:
276	.asciz	"Resume not possible because suspend CPU is no longer available"
277	.align	8
278.Lrestart_diag308_psw:
279	.long	0x00080000,0x80000000
280.Lrestart_suspend_psw:
281	.quad	0x0000000180000000,restart_suspend
282.Lnew_pgm_check_psw:
283	.quad	0,pgm_check_entry
284.Lresume_cpu:
285	.byte	0,0
286