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#include <asm/sigp.h>
 16
 17/*
 18 * Save register context in absolute 0 lowcore and call swsusp_save() to
 19 * create in-memory kernel image. The context is saved in the designated
 20 * "store status" memory locations (see POP).
 21 * We return from this function twice. The first time during the suspend to
 22 * disk process. The second time via the swsusp_arch_resume() function
 23 * (see below) in the resume process.
 24 * This function runs with disabled interrupts.
 25 */
 26	.section .text
 27ENTRY(swsusp_arch_suspend)
 28	stmg	%r6,%r15,__SF_GPRS(%r15)
 29	lgr	%r1,%r15
 30	aghi	%r15,-STACK_FRAME_OVERHEAD
 31	stg	%r1,__SF_BACKCHAIN(%r15)
 32
 33	/* Store FPU registers */
 34	brasl	%r14,save_fpu_regs
 35
 36	/* Deactivate DAT */
 37	stnsm	__SF_EMPTY(%r15),0xfb
 38
 39	/* Store prefix register on stack */
 40	stpx	__SF_EMPTY(%r15)
 41
 42	/* Save prefix register contents for lowcore copy */
 43	llgf	%r10,__SF_EMPTY(%r15)
 44
 45	/* Get pointer to save area */
 46	lghi	%r1,0x1000
 47
 48	/* Save CPU address */
 49	stap	__LC_EXT_CPU_ADDR(%r0)
 50
 51	/* Store registers */
 52	mvc	0x318(4,%r1),__SF_EMPTY(%r15)	/* move prefix to lowcore */
 53	stam	%a0,%a15,0x340(%r1)		/* store access registers */
 54	stctg	%c0,%c15,0x380(%r1)		/* store control registers */
 55	stmg	%r0,%r15,0x280(%r1)		/* store general registers */
 56
 57	stpt	0x328(%r1)			/* store timer */
 58	stck	__SF_EMPTY(%r15)		/* store clock */
 59	stckc	0x330(%r1)			/* store clock comparator */
 60
 61	/* Update cputime accounting before going to sleep */
 62	lg	%r0,__LC_LAST_UPDATE_TIMER
 63	slg	%r0,0x328(%r1)
 64	alg	%r0,__LC_SYSTEM_TIMER
 65	stg	%r0,__LC_SYSTEM_TIMER
 66	mvc	__LC_LAST_UPDATE_TIMER(8),0x328(%r1)
 67	lg	%r0,__LC_LAST_UPDATE_CLOCK
 68	slg	%r0,__SF_EMPTY(%r15)
 69	alg	%r0,__LC_STEAL_TIMER
 70	stg	%r0,__LC_STEAL_TIMER
 71	mvc	__LC_LAST_UPDATE_CLOCK(8),__SF_EMPTY(%r15)
 72
 73	/* Activate DAT */
 74	stosm	__SF_EMPTY(%r15),0x04
 75
 76	/* Set prefix page to zero */
 77	xc	__SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
 78	spx	__SF_EMPTY(%r15)
 79
 80	/* Save absolute zero pages */
 81	larl	%r2,suspend_zero_pages
 82	lg	%r2,0(%r2)
 83	lghi	%r4,0
 84	lghi	%r3,2*PAGE_SIZE
 85	lghi	%r5,2*PAGE_SIZE
 861:	mvcle	%r2,%r4,0
 87	jo	1b
 88
 89	/* Copy lowcore to absolute zero lowcore */
 90	lghi	%r2,0
 91	lgr	%r4,%r10
 92	lghi	%r3,2*PAGE_SIZE
 93	lghi	%r5,2*PAGE_SIZE
 941:	mvcle	%r2,%r4,0
 95	jo	1b
 96
 97	/* Save image */
 98	brasl	%r14,swsusp_save
 99
100	/* Restore prefix register and return */
101	lghi	%r1,0x1000
102	spx	0x318(%r1)
103	lmg	%r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
104	lghi	%r2,0
105	br	%r14
106
107/*
108 * Restore saved memory image to correct place and restore register context.
109 * Then we return to the function that called swsusp_arch_suspend().
110 * swsusp_arch_resume() runs with disabled interrupts.
111 */
112ENTRY(swsusp_arch_resume)
113	stmg	%r6,%r15,__SF_GPRS(%r15)
114	lgr	%r1,%r15
115	aghi	%r15,-STACK_FRAME_OVERHEAD
116	stg	%r1,__SF_BACKCHAIN(%r15)
117
118	/* Make all free pages stable */
119	lghi	%r2,1
120	brasl	%r14,arch_set_page_states
121
122	/* Deactivate DAT */
123	stnsm	__SF_EMPTY(%r15),0xfb
124
125	/* Set prefix page to zero */
126	xc	__SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
127	spx	__SF_EMPTY(%r15)
128
129	/* Restore saved image */
130	larl	%r1,restore_pblist
131	lg	%r1,0(%r1)
132	ltgr	%r1,%r1
133	jz	2f
1340:
135	lg	%r2,8(%r1)
136	lg	%r4,0(%r1)
137	iske	%r0,%r4
138	lghi	%r3,PAGE_SIZE
139	lghi	%r5,PAGE_SIZE
1401:
141	mvcle	%r2,%r4,0
142	jo	1b
143	lg	%r2,8(%r1)
144	sske	%r0,%r2
145	lg	%r1,16(%r1)
146	ltgr	%r1,%r1
147	jnz	0b
1482:
149	ptlb				/* flush tlb */
150
151	/* Reset System */
152	larl	%r1,restart_entry
153	larl	%r2,.Lrestart_diag308_psw
154	og	%r1,0(%r2)
155	stg	%r1,0(%r0)
156	larl	%r1,.Lnew_pgm_check_psw
157	epsw	%r2,%r3
158	stm	%r2,%r3,0(%r1)
159	mvc	__LC_PGM_NEW_PSW(16,%r0),0(%r1)
160	lghi	%r0,0
161	diag	%r0,%r0,0x308
162restart_entry:
163	lhi	%r1,1
164	sigp	%r1,%r0,SIGP_SET_ARCHITECTURE
165	sam64
166#ifdef CONFIG_SMP
167	larl	%r1,smp_cpu_mt_shift
168	icm	%r1,15,0(%r1)
169	jz	smt_done
170	llgfr	%r1,%r1
171smt_loop:
172	sigp	%r1,%r0,SIGP_SET_MULTI_THREADING
173	brc	8,smt_done			/* accepted */
174	brc	2,smt_loop			/* busy, try again */
175smt_done:
176#endif
177	larl	%r1,.Lnew_pgm_check_psw
178	lpswe	0(%r1)
179pgm_check_entry:
180
181	/* Switch to original suspend CPU */
182	larl	%r1,.Lresume_cpu		/* Resume CPU address: r2 */
183	stap	0(%r1)
184	llgh	%r2,0(%r1)
185	llgh	%r1,__LC_EXT_CPU_ADDR(%r0)	/* Suspend CPU address: r1 */
186	cgr	%r1,%r2
187	je	restore_registers		/* r1 = r2 -> nothing to do */
188	larl	%r4,.Lrestart_suspend_psw	/* Set new restart PSW */
189	mvc	__LC_RST_NEW_PSW(16,%r0),0(%r4)
1903:
191	sigp	%r9,%r1,SIGP_INITIAL_CPU_RESET	/* sigp initial cpu reset */
192	brc	8,4f				/* accepted */
193	brc	2,3b				/* busy, try again */
194
195	/* Suspend CPU not available -> panic */
196	larl	%r15,init_thread_union
197	ahi	%r15,1<<(PAGE_SHIFT+THREAD_SIZE_ORDER)
198	larl	%r2,.Lpanic_string
199	larl	%r3,_sclp_print_early
200	lghi	%r1,0
201	sam31
202	sigp	%r1,%r0,SIGP_SET_ARCHITECTURE
203	basr	%r14,%r3
204	larl	%r3,.Ldisabled_wait_31
205	lpsw	0(%r3)
2064:
207	/* Switch to suspend CPU */
208	sigp	%r9,%r1,SIGP_RESTART	/* sigp restart to suspend CPU */
209	brc	2,4b			/* busy, try again */
2105:
211	sigp	%r9,%r2,SIGP_STOP	/* sigp stop to current resume CPU */
212	brc	2,5b			/* busy, try again */
2136:	j	6b
214
215restart_suspend:
216	larl	%r1,.Lresume_cpu
217	llgh	%r2,0(%r1)
2187:
219	sigp	%r9,%r2,SIGP_SENSE	/* sigp sense, wait for resume CPU */
220	brc	8,7b			/* accepted, status 0, still running */
221	brc	2,7b			/* busy, try again */
222	tmll	%r9,0x40		/* Test if resume CPU is stopped */
223	jz	7b
224
225restore_registers:
226	/* Restore registers */
227	lghi	%r13,0x1000		/* %r1 = pointer to save area */
228
229	/* Ignore time spent in suspended state. */
230	llgf	%r1,0x318(%r13)
231	stck	__LC_LAST_UPDATE_CLOCK(%r1)
232	spt	0x328(%r13)		/* reprogram timer */
233	//sckc	0x330(%r13)		/* set clock comparator */
234
235	lctlg	%c0,%c15,0x380(%r13)	/* load control registers */
236	lam	%a0,%a15,0x340(%r13)	/* load access registers */
237
238	/* Load old stack */
239	lg	%r15,0x2f8(%r13)
240
241	/* Save prefix register */
242	mvc __SF_EMPTY(4,%r15),0x318(%r13)
243
244	/* Restore absolute zero pages */
245	lghi	%r2,0
246	larl	%r4,suspend_zero_pages
247	lg	%r4,0(%r4)
248	lghi	%r3,2*PAGE_SIZE
249	lghi	%r5,2*PAGE_SIZE
2501:	mvcle	%r2,%r4,0
251	jo	1b
252
253	/* Restore prefix register */
254	spx	__SF_EMPTY(%r15)
255
256	/* Activate DAT */
257	stosm	__SF_EMPTY(%r15),0x04
258
259	/* Make all free pages unstable */
260	lghi	%r2,0
261	brasl	%r14,arch_set_page_states
262
263	/* Call arch specific early resume code */
264	brasl	%r14,s390_early_resume
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