1 /*
2 *
3 * linux/arch/cris/kernel/setup.c
4 *
5 * Copyright (C) 1995 Linus Torvalds
6 * Copyright (c) 2001 Axis Communications AB
7 */
8
9 /*
10 * This file handles the architecture-dependent parts of initialization
11 */
12
13 #include <linux/init.h>
14 #include <linux/mm.h>
15 #include <linux/bootmem.h>
16 #include <asm/pgtable.h>
17 #include <linux/seq_file.h>
18 #include <linux/screen_info.h>
19 #include <linux/utsname.h>
20 #include <linux/pfn.h>
21 #include <linux/cpu.h>
22 #include <asm/setup.h>
23
24 /*
25 * Setup options
26 */
27 struct screen_info screen_info;
28
29 extern int root_mountflags;
30 extern char _etext, _edata, _end;
31
32 char __initdata cris_command_line[COMMAND_LINE_SIZE] = { 0, };
33
34 extern const unsigned long text_start, edata; /* set by the linker script */
35 extern unsigned long dram_start, dram_end;
36
37 extern unsigned long romfs_start, romfs_length, romfs_in_flash; /* from head.S */
38
39 static struct cpu cpu_devices[NR_CPUS];
40
41 extern void show_etrax_copyright(void); /* arch-vX/kernel/setup.c */
42
43 /* This mainly sets up the memory area, and can be really confusing.
44 *
45 * The physical DRAM is virtually mapped into dram_start to dram_end
46 * (usually c0000000 to c0000000 + DRAM size). The physical address is
47 * given by the macro __pa().
48 *
49 * In this DRAM, the kernel code and data is loaded, in the beginning.
50 * It really starts at c0004000 to make room for some special pages -
51 * the start address is text_start. The kernel data ends at _end. After
52 * this the ROM filesystem is appended (if there is any).
53 *
54 * Between this address and dram_end, we have RAM pages usable to the
55 * boot code and the system.
56 *
57 */
58
setup_arch(char ** cmdline_p)59 void __init setup_arch(char **cmdline_p)
60 {
61 extern void init_etrax_debug(void);
62 unsigned long bootmap_size;
63 unsigned long start_pfn, max_pfn;
64 unsigned long memory_start;
65
66 /* register an initial console printing routine for printk's */
67
68 init_etrax_debug();
69
70 /* we should really poll for DRAM size! */
71
72 high_memory = &dram_end;
73
74 if(romfs_in_flash || !romfs_length) {
75 /* if we have the romfs in flash, or if there is no rom filesystem,
76 * our free area starts directly after the BSS
77 */
78 memory_start = (unsigned long) &_end;
79 } else {
80 /* otherwise the free area starts after the ROM filesystem */
81 printk("ROM fs in RAM, size %lu bytes\n", romfs_length);
82 memory_start = romfs_start + romfs_length;
83 }
84
85 /* process 1's initial memory region is the kernel code/data */
86
87 init_mm.start_code = (unsigned long) &text_start;
88 init_mm.end_code = (unsigned long) &_etext;
89 init_mm.end_data = (unsigned long) &_edata;
90 init_mm.brk = (unsigned long) &_end;
91
92 /* min_low_pfn points to the start of DRAM, start_pfn points
93 * to the first DRAM pages after the kernel, and max_low_pfn
94 * to the end of DRAM.
95 */
96
97 /*
98 * partially used pages are not usable - thus
99 * we are rounding upwards:
100 */
101
102 start_pfn = PFN_UP(memory_start); /* usually c0000000 + kernel + romfs */
103 max_pfn = PFN_DOWN((unsigned long)high_memory); /* usually c0000000 + dram size */
104
105 /*
106 * Initialize the boot-time allocator (start, end)
107 *
108 * We give it access to all our DRAM, but we could as well just have
109 * given it a small slice. No point in doing that though, unless we
110 * have non-contiguous memory and want the boot-stuff to be in, say,
111 * the smallest area.
112 *
113 * It will put a bitmap of the allocated pages in the beginning
114 * of the range we give it, but it won't mark the bitmaps pages
115 * as reserved. We have to do that ourselves below.
116 *
117 * We need to use init_bootmem_node instead of init_bootmem
118 * because our map starts at a quite high address (min_low_pfn).
119 */
120
121 max_low_pfn = max_pfn;
122 min_low_pfn = PAGE_OFFSET >> PAGE_SHIFT;
123
124 bootmap_size = init_bootmem_node(NODE_DATA(0), start_pfn,
125 min_low_pfn,
126 max_low_pfn);
127
128 /* And free all memory not belonging to the kernel (addr, size) */
129
130 free_bootmem(PFN_PHYS(start_pfn), PFN_PHYS(max_pfn - start_pfn));
131
132 /*
133 * Reserve the bootmem bitmap itself as well. We do this in two
134 * steps (first step was init_bootmem()) because this catches
135 * the (very unlikely) case of us accidentally initializing the
136 * bootmem allocator with an invalid RAM area.
137 *
138 * Arguments are start, size
139 */
140
141 reserve_bootmem(PFN_PHYS(start_pfn), bootmap_size, BOOTMEM_DEFAULT);
142
143 /* paging_init() sets up the MMU and marks all pages as reserved */
144
145 paging_init();
146
147 *cmdline_p = cris_command_line;
148
149 #ifdef CONFIG_ETRAX_CMDLINE
150 if (!strcmp(cris_command_line, "")) {
151 strlcpy(cris_command_line, CONFIG_ETRAX_CMDLINE, COMMAND_LINE_SIZE);
152 cris_command_line[COMMAND_LINE_SIZE - 1] = '\0';
153 }
154 #endif
155
156 /* Save command line for future references. */
157 memcpy(boot_command_line, cris_command_line, COMMAND_LINE_SIZE);
158 boot_command_line[COMMAND_LINE_SIZE - 1] = '\0';
159
160 /* give credit for the CRIS port */
161 show_etrax_copyright();
162
163 /* Setup utsname */
164 strcpy(init_utsname()->machine, cris_machine_name);
165 }
166
c_start(struct seq_file * m,loff_t * pos)167 static void *c_start(struct seq_file *m, loff_t *pos)
168 {
169 return *pos < nr_cpu_ids ? (void *)(int)(*pos + 1) : NULL;
170 }
171
c_next(struct seq_file * m,void * v,loff_t * pos)172 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
173 {
174 ++*pos;
175 return c_start(m, pos);
176 }
177
c_stop(struct seq_file * m,void * v)178 static void c_stop(struct seq_file *m, void *v)
179 {
180 }
181
182 extern int show_cpuinfo(struct seq_file *m, void *v);
183
184 const struct seq_operations cpuinfo_op = {
185 .start = c_start,
186 .next = c_next,
187 .stop = c_stop,
188 .show = show_cpuinfo,
189 };
190
topology_init(void)191 static int __init topology_init(void)
192 {
193 int i;
194
195 for_each_possible_cpu(i) {
196 return register_cpu(&cpu_devices[i], i);
197 }
198
199 return 0;
200 }
201
202 subsys_initcall(topology_init);
203
204