1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Chris Dearman (chris@mips.com)
7  * Copyright (C) 2007 Mips Technologies, Inc.
8  * Copyright (C) 2014 Imagination Technologies Ltd.
9  */
10 #ifndef __ASM_MACH_MIPS_KERNEL_ENTRY_INIT_H
11 #define __ASM_MACH_MIPS_KERNEL_ENTRY_INIT_H
12 
13 #include <asm/regdef.h>
14 #include <asm/mipsregs.h>
15 
16 	/*
17 	 * Prepare segments for EVA boot:
18 	 *
19 	 * This is in case the processor boots in legacy configuration
20 	 * (SI_EVAReset is de-asserted and CONFIG5.K == 0)
21 	 *
22 	 * ========================= Mappings =============================
23 	 * Virtual memory           Physical memory           Mapping
24 	 * 0x00000000 - 0x7fffffff  0x80000000 - 0xfffffffff   MUSUK (kuseg)
25 	 *                          Flat 2GB physical memory
26 	 *
27 	 * 0x80000000 - 0x9fffffff  0x00000000 - 0x1ffffffff   MUSUK (kseg0)
28 	 * 0xa0000000 - 0xbf000000  0x00000000 - 0x1ffffffff   MUSUK (kseg1)
29 	 * 0xc0000000 - 0xdfffffff             -                 MK  (kseg2)
30 	 * 0xe0000000 - 0xffffffff             -                 MK  (kseg3)
31 	 *
32 	 *
33 	 * Lowmem is expanded to 2GB
34 	 *
35 	 * The following code uses the t0, t1, t2 and ra registers without
36 	 * previously preserving them.
37 	 *
38 	 */
39 	.macro	platform_eva_init
40 
41 	.set	push
42 	.set	reorder
43 	/*
44 	 * Get Config.K0 value and use it to program
45 	 * the segmentation registers
46 	 */
47 	mfc0    t1, CP0_CONFIG
48 	andi	t1, 0x7 /* CCA */
49 	move	t2, t1
50 	ins	t2, t1, 16, 3
51 	/* SegCtl0 */
52 	li      t0, ((MIPS_SEGCFG_MK << MIPS_SEGCFG_AM_SHIFT) |		\
53 		(0 << MIPS_SEGCFG_PA_SHIFT) |				\
54 		(1 << MIPS_SEGCFG_EU_SHIFT)) |				\
55 		(((MIPS_SEGCFG_MK << MIPS_SEGCFG_AM_SHIFT) |		\
56 		(0 << MIPS_SEGCFG_PA_SHIFT) |				\
57 		(1 << MIPS_SEGCFG_EU_SHIFT)) << 16)
58 	or	t0, t2
59 	mtc0	t0, CP0_SEGCTL0
60 
61 	/* SegCtl1 */
62 	li      t0, ((MIPS_SEGCFG_MUSUK << MIPS_SEGCFG_AM_SHIFT) |	\
63 		(0 << MIPS_SEGCFG_PA_SHIFT) |				\
64 		(2 << MIPS_SEGCFG_C_SHIFT) |				\
65 		(1 << MIPS_SEGCFG_EU_SHIFT)) |				\
66 		(((MIPS_SEGCFG_MUSUK << MIPS_SEGCFG_AM_SHIFT) |		\
67 		(0 << MIPS_SEGCFG_PA_SHIFT) |				\
68 		(1 << MIPS_SEGCFG_EU_SHIFT)) << 16)
69 	ins	t0, t1, 16, 3
70 	mtc0	t0, CP0_SEGCTL1
71 
72 	/* SegCtl2 */
73 	li	t0, ((MIPS_SEGCFG_MUSUK << MIPS_SEGCFG_AM_SHIFT) |	\
74 		(6 << MIPS_SEGCFG_PA_SHIFT) |				\
75 		(1 << MIPS_SEGCFG_EU_SHIFT)) |				\
76 		(((MIPS_SEGCFG_MUSUK << MIPS_SEGCFG_AM_SHIFT) |		\
77 		(4 << MIPS_SEGCFG_PA_SHIFT) |				\
78 		(1 << MIPS_SEGCFG_EU_SHIFT)) << 16)
79 	or	t0, t2
80 	mtc0	t0, CP0_SEGCTL2
81 
82 	jal	mips_ihb
83 	mfc0    t0, $16, 5
84 	li      t2, 0x40000000      /* K bit */
85 	or      t0, t0, t2
86 	mtc0    t0, $16, 5
87 	sync
88 	jal	mips_ihb
89 
90 	.set	pop
91 	.endm
92 
93 	.macro	kernel_entry_setup
94 
95 #ifdef CONFIG_EVA
96 	sync
97 	ehb
98 
99 	mfc0    t1, CP0_CONFIG
100 	bgez    t1, 9f
101 	mfc0	t0, CP0_CONFIG, 1
102 	bgez	t0, 9f
103 	mfc0	t0, CP0_CONFIG, 2
104 	bgez	t0, 9f
105 	mfc0	t0, CP0_CONFIG, 3
106 	sll     t0, t0, 6   /* SC bit */
107 	bgez    t0, 9f
108 
109 	platform_eva_init
110 	b       0f
111 9:
112 	/* Assume we came from YAMON... */
113 	PTR_LA	v0, 0x9fc00534	/* YAMON print */
114 	lw	v0, (v0)
115 	move	a0, zero
116 	PTR_LA  a1, nonsc_processor
117 	jal	v0
118 
119 	PTR_LA	v0, 0x9fc00520	/* YAMON exit */
120 	lw	v0, (v0)
121 	li	a0, 1
122 	jal	v0
123 
124 1:	b	1b
125 	nop
126 	__INITDATA
127 nonsc_processor:
128 	.asciz  "EVA kernel requires a MIPS core with Segment Control implemented\n"
129 	__FINIT
130 #endif /* CONFIG_EVA */
131 0:
132 	.endm
133 
134 /*
135  * Do SMP slave processor setup necessary before we can safely execute C code.
136  */
137 	.macro	smp_slave_setup
138 #ifdef CONFIG_EVA
139 	sync
140 	ehb
141 	platform_eva_init
142 #endif
143 	.endm
144 
145 #endif /* __ASM_MACH_MIPS_KERNEL_ENTRY_INIT_H */
146