xref: /linux/arch/m68k/kernel/relocate_kernel.S (revision 2da68a77) 
1/* SPDX-License-Identifier: GPL-2.0 */
2#include <linux/linkage.h>
3
4#include <asm/asm-offsets.h>
5#include <asm/page.h>
6#include <asm/setup.h>
7
8
9#define MMU_BASE	8		/* MMU flags base in cpu_mmu_flags */
10
11.text
12
13ENTRY(relocate_new_kernel)
14	movel %sp@(4),%a0		/* a0 = ptr */
15	movel %sp@(8),%a1		/* a1 = start */
16	movel %sp@(12),%d1		/* d1 = cpu_mmu_flags */
17	movew #PAGE_MASK,%d2		/* d2 = PAGE_MASK */
18
19	/* Disable MMU */
20
21	btst #MMU_BASE + MMUB_68851,%d1
22	jeq 3f
23
241:	/* 68851 or 68030 */
25
26	lea %pc@(.Lcopy),%a4
272:	addl #0x00000000,%a4		/* virt_to_phys() */
28
29	.section ".m68k_fixup","aw"
30	.long M68K_FIXUP_MEMOFFSET, 2b+2
31	.previous
32
33	.chip 68030
34	pmove %tc,%d0			/* Disable MMU */
35	bclr #7,%d0
36	pmove %d0,%tc
37	jmp %a4@			/* Jump to physical .Lcopy */
38	.chip 68k
39
403:
41	btst #MMU_BASE + MMUB_68030,%d1
42	jne 1b
43
44	btst #MMU_BASE + MMUB_68040,%d1
45	jeq 6f
46
474:	/* 68040 or 68060 */
48
49	lea %pc@(.Lcont040),%a4
505:	addl #0x00000000,%a4		/* virt_to_phys() */
51
52	.section ".m68k_fixup","aw"
53	.long M68K_FIXUP_MEMOFFSET, 5b+2
54	.previous
55
56	movel %a4,%d0
57	andl #0xff000000,%d0
58	orw #0xe020,%d0			/* Map 16 MiB, enable, cacheable */
59	.chip 68040
60	movec %d0,%itt0
61	movec %d0,%dtt0
62	.chip 68k
63	jmp %a4@			/* Jump to physical .Lcont040 */
64
65.Lcont040:
66	moveq #0,%d0
67	.chip 68040
68	movec %d0,%tc			/* Disable MMU */
69	movec %d0,%itt0
70	movec %d0,%itt1
71	movec %d0,%dtt0
72	movec %d0,%dtt1
73	.chip 68k
74	jra .Lcopy
75
766:
77	btst #MMU_BASE + MMUB_68060,%d1
78	jne 4b
79
80.Lcopy:
81	movel %a0@+,%d0			/* d0 = entry = *ptr */
82	jeq .Lflush
83
84	btst #2,%d0			/* entry & IND_DONE? */
85	jne .Lflush
86
87	btst #1,%d0			/* entry & IND_INDIRECTION? */
88	jeq 1f
89	andw %d2,%d0
90	movel %d0,%a0			/* ptr = entry & PAGE_MASK */
91	jra .Lcopy
92
931:
94	btst #0,%d0			/* entry & IND_DESTINATION? */
95	jeq 2f
96	andw %d2,%d0
97	movel %d0,%a2			/* a2 = dst = entry & PAGE_MASK */
98	jra .Lcopy
99
1002:
101	btst #3,%d0			/* entry & IND_SOURCE? */
102	jeq .Lcopy
103
104	andw %d2,%d0
105	movel %d0,%a3			/* a3 = src = entry & PAGE_MASK */
106	movew #PAGE_SIZE/32 - 1,%d0	/* d0 = PAGE_SIZE/32 - 1 */
1073:
108	movel %a3@+,%a2@+		/* *dst++ = *src++ */
109	movel %a3@+,%a2@+		/* *dst++ = *src++ */
110	movel %a3@+,%a2@+		/* *dst++ = *src++ */
111	movel %a3@+,%a2@+		/* *dst++ = *src++ */
112	movel %a3@+,%a2@+		/* *dst++ = *src++ */
113	movel %a3@+,%a2@+		/* *dst++ = *src++ */
114	movel %a3@+,%a2@+		/* *dst++ = *src++ */
115	movel %a3@+,%a2@+		/* *dst++ = *src++ */
116	dbf %d0, 3b
117	jra .Lcopy
118
119.Lflush:
120	/* Flush all caches */
121
122	btst #CPUB_68020,%d1
123	jeq 2f
124
1251:	/* 68020 or 68030 */
126	.chip 68030
127	movec %cacr,%d0
128	orw #0x808,%d0
129	movec %d0,%cacr
130	.chip 68k
131	jra .Lreincarnate
132
1332:
134	btst #CPUB_68030,%d1
135	jne 1b
136
137	btst #CPUB_68040,%d1
138	jeq 4f
139
1403:	/* 68040 or 68060 */
141	.chip 68040
142	nop
143	cpusha %bc
144	nop
145	cinva %bc
146	nop
147	.chip 68k
148	jra .Lreincarnate
149
1504:
151	btst #CPUB_68060,%d1
152	jne 3b
153
154.Lreincarnate:
155	jmp %a1@
156
157relocate_new_kernel_end:
158
159ENTRY(relocate_new_kernel_size)
160	.long relocate_new_kernel_end - relocate_new_kernel
161