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_CPU_ADDRESS(%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	lghi	%r3,PAGE_SIZE
140	lghi	%r5,PAGE_SIZE
1411:
142	mvcle	%r2,%r4,0
143	jo	1b
144	lg	%r1,16(%r1)
145	ltgr	%r1,%r1
146	jnz	0b
1472:
148	ptlb				/* flush tlb */
149
150	/* Reset System */
151	larl	%r1,restart_entry
152	larl	%r2,.Lrestart_diag308_psw
153	og	%r1,0(%r2)
154	stg	%r1,0(%r0)
155	larl	%r1,.Lnew_pgm_check_psw
156	epsw	%r2,%r3
157	stm	%r2,%r3,0(%r1)
158	mvc	__LC_PGM_NEW_PSW(16,%r0),0(%r1)
159	lghi	%r0,0
160	diag	%r0,%r0,0x308
161restart_entry:
162	lhi	%r1,1
163	sigp	%r1,%r0,0x12
164	sam64
165	larl	%r1,.Lnew_pgm_check_psw
166	lpswe	0(%r1)
167pgm_check_entry:
168
169	/* Switch to original suspend CPU */
170	larl	%r1,.Lresume_cpu		/* Resume CPU address: r2 */
171	stap	0(%r1)
172	llgh	%r2,0(%r1)
173	llgh	%r1,__LC_CPU_ADDRESS(%r0)	/* Suspend CPU address: r1 */
174	cgr	%r1,%r2
175	je	restore_registers		/* r1 = r2 -> nothing to do */
176	larl	%r4,.Lrestart_suspend_psw	/* Set new restart PSW */
177	mvc	__LC_RST_NEW_PSW(16,%r0),0(%r4)
1783:
179	sigp	%r9,%r1,__SIGP_INITIAL_CPU_RESET
180	brc	8,4f	/* accepted */
181	brc	2,3b	/* busy, try again */
182
183	/* Suspend CPU not available -> panic */
184	larl	%r15,init_thread_union
185	ahi	%r15,1<<(PAGE_SHIFT+THREAD_ORDER)
186	larl	%r2,.Lpanic_string
187	larl	%r3,_sclp_print_early
188	lghi	%r1,0
189	sam31
190	sigp	%r1,%r0,0x12
191	basr	%r14,%r3
192	larl	%r3,.Ldisabled_wait_31
193	lpsw	0(%r3)
1944:
195	/* Switch to suspend CPU */
196	sigp	%r9,%r1,__SIGP_RESTART	/* start suspend CPU */
197	brc	2,4b			/* busy, try again */
1985:
199	sigp	%r9,%r2,__SIGP_STOP	/* stop resume (current) CPU */
200	brc	2,5b			/* busy, try again */
2016:	j	6b
202
203restart_suspend:
204	larl	%r1,.Lresume_cpu
205	llgh	%r2,0(%r1)
2067:
207	sigp	%r9,%r2,__SIGP_SENSE	/* Wait for resume CPU */
208	brc	8,7b			/* accepted, status 0, still running */
209	brc	2,7b			/* busy, try again */
210	tmll	%r9,0x40		/* Test if resume CPU is stopped */
211	jz	7b
212
213restore_registers:
214	/* Restore registers */
215	lghi	%r13,0x1000		/* %r1 = pointer to save area */
216
217	/* Ignore time spent in suspended state. */
218	llgf	%r1,0x318(%r13)
219	stck	__LC_LAST_UPDATE_CLOCK(%r1)
220	spt	0x328(%r13)		/* reprogram timer */
221	//sckc	0x330(%r13)		/* set clock comparator */
222
223	lctlg	%c0,%c15,0x380(%r13)	/* load control registers */
224	lam	%a0,%a15,0x340(%r13)	/* load access registers */
225
226	lfpc	0x31c(%r13)		/* load fpu control */
227	ld	0,0x200(%r13)		/* load f0 */
228	ld	1,0x208(%r13)		/* load f1 */
229	ld	2,0x210(%r13)		/* load f2 */
230	ld	3,0x218(%r13)		/* load f3 */
231	ld	4,0x220(%r13)		/* load f4 */
232	ld	5,0x228(%r13)		/* load f5 */
233	ld	6,0x230(%r13)		/* load f6 */
234	ld	7,0x238(%r13)		/* load f7 */
235	ld	8,0x240(%r13)		/* load f8 */
236	ld	9,0x248(%r13)		/* load f9 */
237	ld	10,0x250(%r13)		/* load f10 */
238	ld	11,0x258(%r13)		/* load f11 */
239	ld	12,0x260(%r13)		/* load f12 */
240	ld	13,0x268(%r13)		/* load f13 */
241	ld	14,0x270(%r13)		/* load f14 */
242	ld	15,0x278(%r13)		/* load f15 */
243
244	/* Load old stack */
245	lg	%r15,0x2f8(%r13)
246
247	/* Restore prefix register */
248	spx	0x318(%r13)
249
250	/* Activate DAT */
251	stosm	__SF_EMPTY(%r15),0x04
252
253	/* Make all free pages unstable */
254	lghi	%r2,0
255	brasl	%r14,arch_set_page_states
256
257	/* Reinitialize the channel subsystem */
258	brasl	%r14,channel_subsystem_reinit
259
260	/* Return 0 */
261	lmg	%r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
262	lghi	%r2,0
263	br	%r14
264
265	.section .data..nosave,"aw",@progbits
266	.align	8
267.Ldisabled_wait_31:
268	.long  0x000a0000,0x00000000
269.Lpanic_string:
270	.asciz	"Resume not possible because suspend CPU is no longer available"
271	.align	8
272.Lrestart_diag308_psw:
273	.long	0x00080000,0x80000000
274.Lrestart_suspend_psw:
275	.quad	0x0000000180000000,restart_suspend
276.Lnew_pgm_check_psw:
277	.quad	0,pgm_check_entry
278.Lresume_cpu:
279	.byte	0,0