xref: /openbmc/linux/arch/sh/kernel/machvec.c (revision f21e49be)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * arch/sh/kernel/machvec.c
4  *
5  * The SuperH machine vector setup handlers, yanked from setup.c
6  *
7  *  Copyright (C) 1999  Niibe Yutaka
8  *  Copyright (C) 2002 - 2007 Paul Mundt
9  */
10 #include <linux/init.h>
11 #include <linux/string.h>
12 #include <asm/machvec.h>
13 #include <asm/sections.h>
14 #include <asm/addrspace.h>
15 #include <asm/setup.h>
16 #include <asm/io.h>
17 #include <asm/irq.h>
18 #include <asm/processor.h>
19 
20 #define MV_NAME_SIZE 32
21 
22 #define for_each_mv(mv) \
23 	for ((mv) = (struct sh_machine_vector *)&__machvec_start; \
24 	     (mv) && (unsigned long)(mv) < (unsigned long)&__machvec_end; \
25 	     (mv)++)
26 
27 static struct sh_machine_vector * __init get_mv_byname(const char *name)
28 {
29 	struct sh_machine_vector *mv;
30 
31 	for_each_mv(mv)
32 		if (strcasecmp(name, mv->mv_name) == 0)
33 			return mv;
34 
35 	return NULL;
36 }
37 
38 static unsigned int __initdata machvec_selected;
39 
40 static int __init early_parse_mv(char *from)
41 {
42 	char mv_name[MV_NAME_SIZE] = "";
43 	char *mv_end;
44 	char *mv_comma;
45 	int mv_len;
46 	struct sh_machine_vector *mvp;
47 
48 	mv_end = strchr(from, ' ');
49 	if (mv_end == NULL)
50 		mv_end = from + strlen(from);
51 
52 	mv_comma = strchr(from, ',');
53 	mv_len = mv_end - from;
54 	if (mv_len > (MV_NAME_SIZE-1))
55 		mv_len = MV_NAME_SIZE-1;
56 	memcpy(mv_name, from, mv_len);
57 	mv_name[mv_len] = '\0';
58 	from = mv_end;
59 
60 	machvec_selected = 1;
61 
62 	/* Boot with the generic vector */
63 	if (strcmp(mv_name, "generic") == 0)
64 		return 0;
65 
66 	mvp = get_mv_byname(mv_name);
67 	if (unlikely(!mvp)) {
68 		pr_info("Available vectors:\n\n\t'%s', ", sh_mv.mv_name);
69 		for_each_mv(mvp)
70 			pr_cont("'%s', ", mvp->mv_name);
71 		pr_cont("\n\n");
72 		panic("Failed to select machvec '%s' -- halting.\n",
73 		      mv_name);
74 	} else
75 		sh_mv = *mvp;
76 
77 	return 0;
78 }
79 early_param("sh_mv", early_parse_mv);
80 
81 void __init sh_mv_setup(void)
82 {
83 	/*
84 	 * Only overload the machvec if one hasn't been selected on
85 	 * the command line with sh_mv=
86 	 */
87 	if (!machvec_selected) {
88 		unsigned long machvec_size;
89 
90 		machvec_size = ((unsigned long)&__machvec_end -
91 				(unsigned long)&__machvec_start);
92 
93 		/*
94 		 * Sanity check for machvec section alignment. Ensure
95 		 * __initmv hasn't been misused.
96 		 */
97 		if (machvec_size % sizeof(struct sh_machine_vector))
98 			panic("machvec misaligned, invalid __initmv use?");
99 
100 		/*
101 		 * If the machvec hasn't been preselected, use the first
102 		 * vector (usually the only one) from .machvec.init.
103 		 */
104 		if (machvec_size >= sizeof(struct sh_machine_vector))
105 			sh_mv = *(struct sh_machine_vector *)&__machvec_start;
106 	}
107 
108 	pr_notice("Booting machvec: %s\n", get_system_type());
109 
110 	/*
111 	 * Manually walk the vec, fill in anything that the board hasn't yet
112 	 * by hand, wrapping to the generic implementation.
113 	 */
114 #define mv_set(elem) do { \
115 	if (!sh_mv.mv_##elem) \
116 		sh_mv.mv_##elem = generic_##elem; \
117 } while (0)
118 
119 	mv_set(irq_demux);
120 	mv_set(mode_pins);
121 	mv_set(mem_init);
122 }
123