Mark a few variables __read_mostly.
[linux-2.6] / arch / mips / kernel / setup.c
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  * Copyright (C) 1995 Linus Torvalds
7  * Copyright (C) 1995 Waldorf Electronics
8  * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 01, 02, 03  Ralf Baechle
9  * Copyright (C) 1996 Stoned Elipot
10  * Copyright (C) 1999 Silicon Graphics, Inc.
11  * Copyright (C) 2000 2001, 2002  Maciej W. Rozycki
12  */
13 #include <linux/config.h>
14 #include <linux/errno.h>
15 #include <linux/init.h>
16 #include <linux/ioport.h>
17 #include <linux/sched.h>
18 #include <linux/kernel.h>
19 #include <linux/mm.h>
20 #include <linux/module.h>
21 #include <linux/stddef.h>
22 #include <linux/string.h>
23 #include <linux/unistd.h>
24 #include <linux/slab.h>
25 #include <linux/user.h>
26 #include <linux/utsname.h>
27 #include <linux/a.out.h>
28 #include <linux/tty.h>
29 #include <linux/bootmem.h>
30 #include <linux/initrd.h>
31 #include <linux/major.h>
32 #include <linux/kdev_t.h>
33 #include <linux/root_dev.h>
34 #include <linux/highmem.h>
35 #include <linux/console.h>
36 #include <linux/mmzone.h>
37
38 #include <asm/addrspace.h>
39 #include <asm/bootinfo.h>
40 #include <asm/cache.h>
41 #include <asm/cpu.h>
42 #include <asm/sections.h>
43 #include <asm/setup.h>
44 #include <asm/system.h>
45
46 struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;
47
48 EXPORT_SYMBOL(cpu_data);
49
50 #ifdef CONFIG_VT
51 struct screen_info screen_info;
52 #endif
53
54 /*
55  * Despite it's name this variable is even if we don't have PCI
56  */
57 unsigned int PCI_DMA_BUS_IS_PHYS;
58
59 EXPORT_SYMBOL(PCI_DMA_BUS_IS_PHYS);
60
61 /*
62  * Setup information
63  *
64  * These are initialized so they are in the .data section
65  */
66 unsigned long mips_machtype __read_mostly = MACH_UNKNOWN;
67 unsigned long mips_machgroup __read_mostly = MACH_GROUP_UNKNOWN;
68
69 EXPORT_SYMBOL(mips_machtype);
70 EXPORT_SYMBOL(mips_machgroup);
71
72 struct boot_mem_map boot_mem_map;
73
74 static char command_line[CL_SIZE];
75        char arcs_cmdline[CL_SIZE]=CONFIG_CMDLINE;
76
77 /*
78  * mips_io_port_base is the begin of the address space to which x86 style
79  * I/O ports are mapped.
80  */
81 const unsigned long mips_io_port_base __read_mostly = -1;
82 EXPORT_SYMBOL(mips_io_port_base);
83
84 /*
85  * isa_slot_offset is the address where E(ISA) busaddress 0 is mapped
86  * for the processor.
87  */
88 unsigned long isa_slot_offset;
89 EXPORT_SYMBOL(isa_slot_offset);
90
91 static struct resource code_resource = { .name = "Kernel code", };
92 static struct resource data_resource = { .name = "Kernel data", };
93
94 void __init add_memory_region(phys_t start, phys_t size, long type)
95 {
96         int x = boot_mem_map.nr_map;
97         struct boot_mem_map_entry *prev = boot_mem_map.map + x - 1;
98
99         /*
100          * Try to merge with previous entry if any.  This is far less than
101          * perfect but is sufficient for most real world cases.
102          */
103         if (x && prev->addr + prev->size == start && prev->type == type) {
104                 prev->size += size;
105                 return;
106         }
107
108         if (x == BOOT_MEM_MAP_MAX) {
109                 printk("Ooops! Too many entries in the memory map!\n");
110                 return;
111         }
112
113         boot_mem_map.map[x].addr = start;
114         boot_mem_map.map[x].size = size;
115         boot_mem_map.map[x].type = type;
116         boot_mem_map.nr_map++;
117 }
118
119 static void __init print_memory_map(void)
120 {
121         int i;
122         const int field = 2 * sizeof(unsigned long);
123
124         for (i = 0; i < boot_mem_map.nr_map; i++) {
125                 printk(" memory: %0*Lx @ %0*Lx ",
126                        field, (unsigned long long) boot_mem_map.map[i].size,
127                        field, (unsigned long long) boot_mem_map.map[i].addr);
128
129                 switch (boot_mem_map.map[i].type) {
130                 case BOOT_MEM_RAM:
131                         printk("(usable)\n");
132                         break;
133                 case BOOT_MEM_ROM_DATA:
134                         printk("(ROM data)\n");
135                         break;
136                 case BOOT_MEM_RESERVED:
137                         printk("(reserved)\n");
138                         break;
139                 default:
140                         printk("type %lu\n", boot_mem_map.map[i].type);
141                         break;
142                 }
143         }
144 }
145
146 static inline void parse_cmdline_early(void)
147 {
148         char c = ' ', *to = command_line, *from = saved_command_line;
149         unsigned long start_at, mem_size;
150         int len = 0;
151         int usermem = 0;
152
153         printk("Determined physical RAM map:\n");
154         print_memory_map();
155
156         for (;;) {
157                 /*
158                  * "mem=XXX[kKmM]" defines a memory region from
159                  * 0 to <XXX>, overriding the determined size.
160                  * "mem=XXX[KkmM]@YYY[KkmM]" defines a memory region from
161                  * <YYY> to <YYY>+<XXX>, overriding the determined size.
162                  */
163                 if (c == ' ' && !memcmp(from, "mem=", 4)) {
164                         if (to != command_line)
165                                 to--;
166                         /*
167                          * If a user specifies memory size, we
168                          * blow away any automatically generated
169                          * size.
170                          */
171                         if (usermem == 0) {
172                                 boot_mem_map.nr_map = 0;
173                                 usermem = 1;
174                         }
175                         mem_size = memparse(from + 4, &from);
176                         if (*from == '@')
177                                 start_at = memparse(from + 1, &from);
178                         else
179                                 start_at = 0;
180                         add_memory_region(start_at, mem_size, BOOT_MEM_RAM);
181                 }
182                 c = *(from++);
183                 if (!c)
184                         break;
185                 if (CL_SIZE <= ++len)
186                         break;
187                 *(to++) = c;
188         }
189         *to = '\0';
190
191         if (usermem) {
192                 printk("User-defined physical RAM map:\n");
193                 print_memory_map();
194         }
195 }
196
197 static inline int parse_rd_cmdline(unsigned long* rd_start, unsigned long* rd_end)
198 {
199         /*
200          * "rd_start=0xNNNNNNNN" defines the memory address of an initrd
201          * "rd_size=0xNN" it's size
202          */
203         unsigned long start = 0;
204         unsigned long size = 0;
205         unsigned long end;
206         char cmd_line[CL_SIZE];
207         char *start_str;
208         char *size_str;
209         char *tmp;
210
211         strcpy(cmd_line, command_line);
212         *command_line = 0;
213         tmp = cmd_line;
214         /* Ignore "rd_start=" strings in other parameters. */
215         start_str = strstr(cmd_line, "rd_start=");
216         if (start_str && start_str != cmd_line && *(start_str - 1) != ' ')
217                 start_str = strstr(start_str, " rd_start=");
218         while (start_str) {
219                 if (start_str != cmd_line)
220                         strncat(command_line, tmp, start_str - tmp);
221                 start = memparse(start_str + 9, &start_str);
222                 tmp = start_str + 1;
223                 start_str = strstr(start_str, " rd_start=");
224         }
225         if (*tmp)
226                 strcat(command_line, tmp);
227
228         strcpy(cmd_line, command_line);
229         *command_line = 0;
230         tmp = cmd_line;
231         /* Ignore "rd_size" strings in other parameters. */
232         size_str = strstr(cmd_line, "rd_size=");
233         if (size_str && size_str != cmd_line && *(size_str - 1) != ' ')
234                 size_str = strstr(size_str, " rd_size=");
235         while (size_str) {
236                 if (size_str != cmd_line)
237                         strncat(command_line, tmp, size_str - tmp);
238                 size = memparse(size_str + 8, &size_str);
239                 tmp = size_str + 1;
240                 size_str = strstr(size_str, " rd_size=");
241         }
242         if (*tmp)
243                 strcat(command_line, tmp);
244
245 #ifdef CONFIG_64BIT
246         /* HACK: Guess if the sign extension was forgotten */
247         if (start > 0x0000000080000000 && start < 0x00000000ffffffff)
248                 start |= 0xffffffff00000000;
249 #endif
250
251         end = start + size;
252         if (start && end) {
253                 *rd_start = start;
254                 *rd_end = end;
255                 return 1;
256         }
257         return 0;
258 }
259
260 #define PFN_UP(x)       (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT)
261 #define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
262 #define PFN_PHYS(x)     ((x) << PAGE_SHIFT)
263
264 #define MAXMEM          HIGHMEM_START
265 #define MAXMEM_PFN      PFN_DOWN(MAXMEM)
266
267 static inline void bootmem_init(void)
268 {
269         unsigned long start_pfn;
270         unsigned long reserved_end = (unsigned long)&_end;
271 #ifndef CONFIG_SGI_IP27
272         unsigned long first_usable_pfn;
273         unsigned long bootmap_size;
274         int i;
275 #endif
276 #ifdef CONFIG_BLK_DEV_INITRD
277         int initrd_reserve_bootmem = 0;
278
279         /* Board specific code should have set up initrd_start and initrd_end */
280         ROOT_DEV = Root_RAM0;
281         if (parse_rd_cmdline(&initrd_start, &initrd_end)) {
282                 reserved_end = max(reserved_end, initrd_end);
283                 initrd_reserve_bootmem = 1;
284         } else {
285                 unsigned long tmp;
286                 u32 *initrd_header;
287
288                 tmp = ((reserved_end + PAGE_SIZE-1) & PAGE_MASK) - sizeof(u32) * 2;
289                 if (tmp < reserved_end)
290                         tmp += PAGE_SIZE;
291                 initrd_header = (u32 *)tmp;
292                 if (initrd_header[0] == 0x494E5244) {
293                         initrd_start = (unsigned long)&initrd_header[2];
294                         initrd_end = initrd_start + initrd_header[1];
295                         reserved_end = max(reserved_end, initrd_end);
296                         initrd_reserve_bootmem = 1;
297                 }
298         }
299 #endif  /* CONFIG_BLK_DEV_INITRD */
300
301         /*
302          * Partially used pages are not usable - thus
303          * we are rounding upwards.
304          */
305         start_pfn = PFN_UP(CPHYSADDR(reserved_end));
306
307 #ifndef CONFIG_SGI_IP27
308         /* Find the highest page frame number we have available.  */
309         max_pfn = 0;
310         first_usable_pfn = -1UL;
311         for (i = 0; i < boot_mem_map.nr_map; i++) {
312                 unsigned long start, end;
313
314                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
315                         continue;
316
317                 start = PFN_UP(boot_mem_map.map[i].addr);
318                 end = PFN_DOWN(boot_mem_map.map[i].addr
319                       + boot_mem_map.map[i].size);
320
321                 if (start >= end)
322                         continue;
323                 if (end > max_pfn)
324                         max_pfn = end;
325                 if (start < first_usable_pfn) {
326                         if (start > start_pfn) {
327                                 first_usable_pfn = start;
328                         } else if (end > start_pfn) {
329                                 first_usable_pfn = start_pfn;
330                         }
331                 }
332         }
333
334         /*
335          * Determine low and high memory ranges
336          */
337         max_low_pfn = max_pfn;
338         if (max_low_pfn > MAXMEM_PFN) {
339                 max_low_pfn = MAXMEM_PFN;
340 #ifndef CONFIG_HIGHMEM
341                 /* Maximum memory usable is what is directly addressable */
342                 printk(KERN_WARNING "Warning only %ldMB will be used.\n",
343                        MAXMEM >> 20);
344                 printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
345 #endif
346         }
347
348 #ifdef CONFIG_HIGHMEM
349         /*
350          * Crude, we really should make a better attempt at detecting
351          * highstart_pfn
352          */
353         highstart_pfn = highend_pfn = max_pfn;
354         if (max_pfn > MAXMEM_PFN) {
355                 highstart_pfn = MAXMEM_PFN;
356                 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
357                        (highend_pfn - highstart_pfn) >> (20 - PAGE_SHIFT));
358         }
359 #endif
360
361         memory_present(0, first_usable_pfn, max_low_pfn);
362
363         /* Initialize the boot-time allocator with low memory only.  */
364         bootmap_size = init_bootmem(first_usable_pfn, max_low_pfn);
365
366         /*
367          * Register fully available low RAM pages with the bootmem allocator.
368          */
369         for (i = 0; i < boot_mem_map.nr_map; i++) {
370                 unsigned long curr_pfn, last_pfn, size;
371
372                 /*
373                  * Reserve usable memory.
374                  */
375                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
376                         continue;
377
378                 /*
379                  * We are rounding up the start address of usable memory:
380                  */
381                 curr_pfn = PFN_UP(boot_mem_map.map[i].addr);
382                 if (curr_pfn >= max_low_pfn)
383                         continue;
384                 if (curr_pfn < start_pfn)
385                         curr_pfn = start_pfn;
386
387                 /*
388                  * ... and at the end of the usable range downwards:
389                  */
390                 last_pfn = PFN_DOWN(boot_mem_map.map[i].addr
391                                     + boot_mem_map.map[i].size);
392
393                 if (last_pfn > max_low_pfn)
394                         last_pfn = max_low_pfn;
395
396                 /*
397                  * Only register lowmem part of lowmem segment with bootmem.
398                  */
399                 size = last_pfn - curr_pfn;
400                 if (curr_pfn > PFN_DOWN(HIGHMEM_START))
401                         continue;
402                 if (curr_pfn + size - 1 > PFN_DOWN(HIGHMEM_START))
403                         size = PFN_DOWN(HIGHMEM_START) - curr_pfn;
404                 if (!size)
405                         continue;
406
407                 /*
408                  * ... finally, did all the rounding and playing
409                  * around just make the area go away?
410                  */
411                 if (last_pfn <= curr_pfn)
412                         continue;
413
414                 /* Register lowmem ranges */
415                 free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
416         }
417
418         /* Reserve the bootmap memory.  */
419         reserve_bootmem(PFN_PHYS(first_usable_pfn), bootmap_size);
420 #endif /* CONFIG_SGI_IP27 */
421
422 #ifdef CONFIG_BLK_DEV_INITRD
423         initrd_below_start_ok = 1;
424         if (initrd_start) {
425                 unsigned long initrd_size = ((unsigned char *)initrd_end) - ((unsigned char *)initrd_start);
426                 printk("Initial ramdisk at: 0x%p (%lu bytes)\n",
427                        (void *)initrd_start, initrd_size);
428
429                 if (CPHYSADDR(initrd_end) > PFN_PHYS(max_low_pfn)) {
430                         printk("initrd extends beyond end of memory "
431                                "(0x%0*Lx > 0x%0*Lx)\ndisabling initrd\n",
432                                sizeof(long) * 2,
433                                (unsigned long long)CPHYSADDR(initrd_end),
434                                sizeof(long) * 2,
435                                (unsigned long long)PFN_PHYS(max_low_pfn));
436                         initrd_start = initrd_end = 0;
437                         initrd_reserve_bootmem = 0;
438                 }
439
440                 if (initrd_reserve_bootmem)
441                         reserve_bootmem(CPHYSADDR(initrd_start), initrd_size);
442         }
443 #endif /* CONFIG_BLK_DEV_INITRD  */
444 }
445
446 static inline void resource_init(void)
447 {
448         int i;
449
450 #if defined(CONFIG_64BIT) && !defined(CONFIG_BUILD_ELF64)
451         /*
452          * The 64bit code in 32bit object format trick can't represent
453          * 64bit wide relocations for linker script symbols.
454          */
455         code_resource.start = CPHYSADDR(&_text);
456         code_resource.end = CPHYSADDR(&_etext) - 1;
457         data_resource.start = CPHYSADDR(&_etext);
458         data_resource.end = CPHYSADDR(&_edata) - 1;
459 #else
460         code_resource.start = virt_to_phys(&_text);
461         code_resource.end = virt_to_phys(&_etext) - 1;
462         data_resource.start = virt_to_phys(&_etext);
463         data_resource.end = virt_to_phys(&_edata) - 1;
464 #endif
465
466         /*
467          * Request address space for all standard RAM.
468          */
469         for (i = 0; i < boot_mem_map.nr_map; i++) {
470                 struct resource *res;
471                 unsigned long start, end;
472
473                 start = boot_mem_map.map[i].addr;
474                 end = boot_mem_map.map[i].addr + boot_mem_map.map[i].size - 1;
475                 if (start >= MAXMEM)
476                         continue;
477                 if (end >= MAXMEM)
478                         end = MAXMEM - 1;
479
480                 res = alloc_bootmem(sizeof(struct resource));
481                 switch (boot_mem_map.map[i].type) {
482                 case BOOT_MEM_RAM:
483                 case BOOT_MEM_ROM_DATA:
484                         res->name = "System RAM";
485                         break;
486                 case BOOT_MEM_RESERVED:
487                 default:
488                         res->name = "reserved";
489                 }
490
491                 res->start = start;
492                 res->end = end;
493
494                 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
495                 request_resource(&iomem_resource, res);
496
497                 /*
498                  *  We don't know which RAM region contains kernel data,
499                  *  so we try it repeatedly and let the resource manager
500                  *  test it.
501                  */
502                 request_resource(res, &code_resource);
503                 request_resource(res, &data_resource);
504         }
505 }
506
507 #undef PFN_UP
508 #undef PFN_DOWN
509 #undef PFN_PHYS
510
511 #undef MAXMEM
512 #undef MAXMEM_PFN
513
514 extern void plat_setup(void);
515
516 void __init setup_arch(char **cmdline_p)
517 {
518         cpu_probe();
519         prom_init();
520         cpu_report();
521
522 #if defined(CONFIG_VT)
523 #if defined(CONFIG_VGA_CONSOLE)
524         conswitchp = &vga_con;
525 #elif defined(CONFIG_DUMMY_CONSOLE)
526         conswitchp = &dummy_con;
527 #endif
528 #endif
529
530         /* call board setup routine */
531         plat_setup();
532
533         strlcpy(command_line, arcs_cmdline, sizeof(command_line));
534         strlcpy(saved_command_line, command_line, COMMAND_LINE_SIZE);
535
536         *cmdline_p = command_line;
537
538         parse_cmdline_early();
539         bootmem_init();
540         sparse_init();
541         paging_init();
542         resource_init();
543 }
544
545 int __init fpu_disable(char *s)
546 {
547         cpu_data[0].options &= ~MIPS_CPU_FPU;
548
549         return 1;
550 }
551
552 __setup("nofpu", fpu_disable);
553
554 int __init dsp_disable(char *s)
555 {
556         cpu_data[0].ases &= ~MIPS_ASE_DSP;
557
558         return 1;
559 }
560
561 __setup("nodsp", dsp_disable);