xref: /openbmc/linux/arch/sh/kernel/cpu/sh3/swsusp.S (revision f2f4bf5a) 
1/* SPDX-License-Identifier: GPL-2.0
2 *
3 * arch/sh/kernel/cpu/sh3/swsusp.S
4 *
5 * Copyright (C) 2009 Magnus Damm
6 */
7#include <linux/sys.h>
8#include <linux/errno.h>
9#include <linux/linkage.h>
10#include <asm/asm-offsets.h>
11#include <asm/page.h>
12
13#define k0	r0
14#define k1	r1
15#define k2	r2
16#define k3	r3
17#define k4	r4
18
19! swsusp_arch_resume()
20! - copy restore_pblist pages
21! - restore registers from swsusp_arch_regs_cpu0
22
23ENTRY(swsusp_arch_resume)
24	mov.l	1f, r15
25	mov.l	2f, r4
26	mov.l	@r4, r4
27
28swsusp_copy_loop:
29	mov	r4, r0
30	cmp/eq	#0, r0
31	bt	swsusp_restore_regs
32
33	mov.l	@(PBE_ADDRESS, r4), r2
34	mov.l	@(PBE_ORIG_ADDRESS, r4), r5
35
36	mov	#(PAGE_SIZE >> 10), r3
37	shll8	r3
38	shlr2	r3 /* PAGE_SIZE / 16 */
39swsusp_copy_page:
40	dt	r3
41	mov.l	@r2+,r1   /*  16n+0 */
42	mov.l	r1,@r5
43	add	#4,r5
44	mov.l	@r2+,r1	  /*  16n+4 */
45	mov.l	r1,@r5
46	add	#4,r5
47	mov.l	@r2+,r1   /*  16n+8 */
48	mov.l	r1,@r5
49	add	#4,r5
50	mov.l	@r2+,r1   /*  16n+12 */
51	mov.l	r1,@r5
52	bf/s	swsusp_copy_page
53	 add	#4,r5
54
55	bra	swsusp_copy_loop
56	 mov.l	@(PBE_NEXT, r4), r4
57
58swsusp_restore_regs:
59	! BL=0: R7->R0 is bank0
60	mov.l	3f, r8
61	mov.l	4f, r5
62	jsr	@r5
63	 nop
64
65	! BL=1: R7->R0 is bank1
66	lds	k2, pr
67	ldc	k3, ssr
68
69	mov.l	@r15+, r0
70	mov.l	@r15+, r1
71	mov.l	@r15+, r2
72	mov.l	@r15+, r3
73	mov.l	@r15+, r4
74	mov.l	@r15+, r5
75	mov.l	@r15+, r6
76	mov.l	@r15+, r7
77
78	rte
79	 nop
80	! BL=0: R7->R0 is bank0
81
82	.align	2
831:	.long	swsusp_arch_regs_cpu0
842:	.long	restore_pblist
853:	.long	0x20000000 ! RB=1
864:	.long	restore_regs
87
88! swsusp_arch_suspend()
89! - prepare pc for resume, return from function without swsusp_save on resume
90! - save registers in swsusp_arch_regs_cpu0
91! - call swsusp_save write suspend image
92
93ENTRY(swsusp_arch_suspend)
94	sts	pr, r0		! save pr in r0
95	mov	r15, r2		! save sp in r2
96	mov	r8, r5		! save r8 in r5
97	stc	sr, r1
98	ldc	r1, ssr		! save sr in ssr
99	mov.l	1f, r1
100	ldc	r1, spc		! setup pc value for resuming
101	mov.l	5f, r15		! use swsusp_arch_regs_cpu0 as stack
102	mov.l	6f, r3
103	add	r3, r15		! save from top of structure
104
105	! BL=0: R7->R0 is bank0
106	mov.l	2f, r3		! get new SR value for bank1
107	mov	#0, r4
108	mov.l	7f, r1
109	jsr	@r1		! switch to bank1 and save bank1 r7->r0
110	 not	r4, r4
111
112	! BL=1: R7->R0 is bank1
113	stc	r2_bank, k0	! fetch old sp from r2_bank0
114	mov.l	3f, k4		! SR bits to clear in k4
115	mov.l	8f, k1
116	jsr	@k1		! switch to bank0 and save all regs
117	 stc	r0_bank, k3	! fetch old pr from r0_bank0
118
119	! BL=0: R7->R0 is bank0
120	mov	r2, r15		! restore old sp
121	mov	r5, r8		! restore old r8
122	stc	ssr, r1
123	ldc	r1, sr		! restore old sr
124	lds	r0, pr		! restore old pr
125	mov.l	4f, r0
126	jmp	@r0
127	 nop
128
129swsusp_call_save:
130	mov	r2, r15		! restore old sp
131	mov	r5, r8		! restore old r8
132	lds	r0, pr		! restore old pr
133	rts
134	 mov	#0, r0
135
136	.align	2
1371:	.long	swsusp_call_save
1382:	.long	0x20000000 ! RB=1
1393:	.long	0xdfffffff ! RB=0
1404:	.long	swsusp_save
1415:	.long	swsusp_arch_regs_cpu0
1426:	.long	SWSUSP_ARCH_REGS_SIZE
1437:	.long	save_low_regs
1448:	.long	save_regs
145