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setup.c
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1 /*
2  * Copyright (C) 2004-2006 Atmel Corporation
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/init.h>
11 #include <linux/initrd.h>
12 #include <linux/sched.h>
13 #include <linux/console.h>
14 #include <linux/ioport.h>
15 #include <linux/bootmem.h>
16 #include <linux/fs.h>
17 #include <linux/module.h>
18 #include <linux/pfn.h>
19 #include <linux/root_dev.h>
20 #include <linux/cpu.h>
21 #include <linux/kernel.h>
22 
23 #include <asm/sections.h>
24 #include <asm/processor.h>
25 #include <asm/pgtable.h>
26 #include <asm/setup.h>
27 #include <asm/sysreg.h>
28 
29 #include <mach/board.h>
30 #include <mach/init.h>
31 
32 extern int root_mountflags;
33 
34 /*
35  * Initialize loops_per_jiffy as 5000000 (500MIPS).
36  * Better make it too large than too small...
37  */
39  .loops_per_jiffy = 5000000
40 };
41 EXPORT_SYMBOL(boot_cpu_data);
42 
43 static char __initdata command_line[COMMAND_LINE_SIZE];
44 
45 /*
46  * Standard memory resources
47  */
48 static struct resource __initdata kernel_data = {
49  .name = "Kernel data",
50  .start = 0,
51  .end = 0,
52  .flags = IORESOURCE_MEM,
53 };
54 static struct resource __initdata kernel_code = {
55  .name = "Kernel code",
56  .start = 0,
57  .end = 0,
58  .flags = IORESOURCE_MEM,
59  .sibling = &kernel_data,
60 };
61 
62 /*
63  * Available system RAM and reserved regions as singly linked
64  * lists. These lists are traversed using the sibling pointer in
65  * struct resource and are kept sorted at all times.
66  */
67 static struct resource *__initdata system_ram;
68 static struct resource *__initdata reserved = &kernel_code;
69 
70 /*
71  * We need to allocate these before the bootmem allocator is up and
72  * running, so we need this "cache". 32 entries are probably enough
73  * for all but the most insanely complex systems.
74  */
75 static struct resource __initdata res_cache[32];
76 static unsigned int __initdata res_cache_next_free;
77 
78 static void __init resource_init(void)
79 {
80  struct resource *mem, *res;
81  struct resource *new;
82 
83  kernel_code.start = __pa(init_mm.start_code);
84 
85  for (mem = system_ram; mem; mem = mem->sibling) {
86  new = alloc_bootmem_low(sizeof(struct resource));
87  memcpy(new, mem, sizeof(struct resource));
88 
89  new->sibling = NULL;
91  printk(KERN_WARNING "Bad RAM resource %08x-%08x\n",
92  mem->start, mem->end);
93  }
94 
95  for (res = reserved; res; res = res->sibling) {
96  new = alloc_bootmem_low(sizeof(struct resource));
97  memcpy(new, res, sizeof(struct resource));
98 
99  new->sibling = NULL;
100  if (insert_resource(&iomem_resource, new))
102  "Bad reserved resource %s (%08x-%08x)\n",
103  res->name, res->start, res->end);
104  }
105 }
106 
107 static void __init
108 add_physical_memory(resource_size_t start, resource_size_t end)
109 {
110  struct resource *new, *next, **pprev;
111 
112  for (pprev = &system_ram, next = system_ram; next;
113  pprev = &next->sibling, next = next->sibling) {
114  if (end < next->start)
115  break;
116  if (start <= next->end) {
118  "Warning: Physical memory map is broken\n");
120  "Warning: %08x-%08x overlaps %08x-%08x\n",
121  start, end, next->start, next->end);
122  return;
123  }
124  }
125 
126  if (res_cache_next_free >= ARRAY_SIZE(res_cache)) {
128  "Warning: Failed to add physical memory %08x-%08x\n",
129  start, end);
130  return;
131  }
132 
133  new = &res_cache[res_cache_next_free++];
134  new->start = start;
135  new->end = end;
136  new->name = "System RAM";
137  new->flags = IORESOURCE_MEM;
138 
139  *pprev = new;
140 }
141 
142 static int __init
143 add_reserved_region(resource_size_t start, resource_size_t end,
144  const char *name)
145 {
146  struct resource *new, *next, **pprev;
147 
148  if (end < start)
149  return -EINVAL;
150 
151  if (res_cache_next_free >= ARRAY_SIZE(res_cache))
152  return -ENOMEM;
153 
154  for (pprev = &reserved, next = reserved; next;
155  pprev = &next->sibling, next = next->sibling) {
156  if (end < next->start)
157  break;
158  if (start <= next->end)
159  return -EBUSY;
160  }
161 
162  new = &res_cache[res_cache_next_free++];
163  new->start = start;
164  new->end = end;
165  new->name = name;
166  new->sibling = next;
167  new->flags = IORESOURCE_MEM;
168 
169  *pprev = new;
170 
171  return 0;
172 }
173 
174 static unsigned long __init
175 find_free_region(const struct resource *mem, resource_size_t size,
177 {
178  struct resource *res;
179  unsigned long target;
180 
181  target = ALIGN(mem->start, align);
182  for (res = reserved; res; res = res->sibling) {
183  if ((target + size) <= res->start)
184  break;
185  if (target <= res->end)
186  target = ALIGN(res->end + 1, align);
187  }
188 
189  if ((target + size) > (mem->end + 1))
190  return mem->end + 1;
191 
192  return target;
193 }
194 
195 static int __init
196 alloc_reserved_region(resource_size_t *start, resource_size_t size,
197  resource_size_t align, const char *name)
198 {
199  struct resource *mem;
201  int ret;
202 
203  for (mem = system_ram; mem; mem = mem->sibling) {
204  target = find_free_region(mem, size, align);
205  if (target <= mem->end) {
206  ret = add_reserved_region(target, target + size - 1,
207  name);
208  if (!ret)
209  *start = target;
210  return ret;
211  }
212  }
213 
214  return -ENOMEM;
215 }
216 
217 /*
218  * Early framebuffer allocation. Works as follows:
219  * - If fbmem_size is zero, nothing will be allocated or reserved.
220  * - If fbmem_start is zero when setup_bootmem() is called,
221  * a block of fbmem_size bytes will be reserved before bootmem
222  * initialization. It will be aligned to the largest page size
223  * that fbmem_size is a multiple of.
224  * - If fbmem_start is nonzero, an area of size fbmem_size will be
225  * reserved at the physical address fbmem_start if possible. If
226  * it collides with other reserved memory, a different block of
227  * same size will be allocated, just as if fbmem_start was zero.
228  *
229  * Board-specific code may use these variables to set up platform data
230  * for the framebuffer driver if fbmem_size is nonzero.
231  */
234 
235 /*
236  * "fbmem=xxx[kKmM]" allocates the specified amount of boot memory for
237  * use as framebuffer.
238  *
239  * "fbmem=xxx[kKmM]@yyy[kKmM]" defines a memory region of size xxx and
240  * starting at yyy to be reserved for use as framebuffer.
241  *
242  * The kernel won't verify that the memory region starting at yyy
243  * actually contains usable RAM.
244  */
245 static int __init early_parse_fbmem(char *p)
246 {
247  int ret;
248  unsigned long align;
249 
250  fbmem_size = memparse(p, &p);
251  if (*p == '@') {
252  fbmem_start = memparse(p + 1, &p);
253  ret = add_reserved_region(fbmem_start,
254  fbmem_start + fbmem_size - 1,
255  "Framebuffer");
256  if (ret) {
258  "Failed to reserve framebuffer memory\n");
259  fbmem_start = 0;
260  }
261  }
262 
263  if (!fbmem_start) {
264  if ((fbmem_size & 0x000fffffUL) == 0)
265  align = 0x100000; /* 1 MiB */
266  else if ((fbmem_size & 0x0000ffffUL) == 0)
267  align = 0x10000; /* 64 KiB */
268  else
269  align = 0x1000; /* 4 KiB */
270 
271  ret = alloc_reserved_region(&fbmem_start, fbmem_size,
272  align, "Framebuffer");
273  if (ret) {
275  "Failed to allocate framebuffer memory\n");
276  fbmem_size = 0;
277  } else {
278  memset(__va(fbmem_start), 0, fbmem_size);
279  }
280  }
281 
282  return 0;
283 }
284 early_param("fbmem", early_parse_fbmem);
285 
286 /*
287  * Pick out the memory size. We look for mem=size@start,
288  * where start and size are "size[KkMmGg]"
289  */
290 static int __init early_mem(char *p)
291 {
293 
294  start = system_ram->start;
295  size = memparse(p, &p);
296  if (*p == '@')
297  start = memparse(p + 1, &p);
298 
299  system_ram->start = start;
300  system_ram->end = system_ram->start + size - 1;
301  return 0;
302 }
303 early_param("mem", early_mem);
304 
305 static int __init parse_tag_core(struct tag *tag)
306 {
307  if (tag->hdr.size > 2) {
308  if ((tag->u.core.flags & 1) == 0)
310  ROOT_DEV = new_decode_dev(tag->u.core.rootdev);
311  }
312  return 0;
313 }
314 __tagtable(ATAG_CORE, parse_tag_core);
315 
316 static int __init parse_tag_mem(struct tag *tag)
317 {
318  unsigned long start, end;
319 
320  /*
321  * Ignore zero-sized entries. If we're running standalone, the
322  * SDRAM code may emit such entries if something goes
323  * wrong...
324  */
325  if (tag->u.mem_range.size == 0)
326  return 0;
327 
328  start = tag->u.mem_range.addr;
329  end = tag->u.mem_range.addr + tag->u.mem_range.size - 1;
330 
331  add_physical_memory(start, end);
332  return 0;
333 }
334 __tagtable(ATAG_MEM, parse_tag_mem);
335 
336 static int __init parse_tag_rdimg(struct tag *tag)
337 {
338 #ifdef CONFIG_BLK_DEV_INITRD
339  struct tag_mem_range *mem = &tag->u.mem_range;
340  int ret;
341 
342  if (initrd_start) {
344  "Warning: Only the first initrd image will be used\n");
345  return 0;
346  }
347 
348  ret = add_reserved_region(mem->addr, mem->addr + mem->size - 1,
349  "initrd");
350  if (ret) {
352  "Warning: Failed to reserve initrd memory\n");
353  return ret;
354  }
355 
356  initrd_start = (unsigned long)__va(mem->addr);
357  initrd_end = initrd_start + mem->size;
358 #else
359  printk(KERN_WARNING "RAM disk image present, but "
360  "no initrd support in kernel, ignoring\n");
361 #endif
362 
363  return 0;
364 }
365 __tagtable(ATAG_RDIMG, parse_tag_rdimg);
366 
367 static int __init parse_tag_rsvd_mem(struct tag *tag)
368 {
369  struct tag_mem_range *mem = &tag->u.mem_range;
370 
371  return add_reserved_region(mem->addr, mem->addr + mem->size - 1,
372  "Reserved");
373 }
374 __tagtable(ATAG_RSVD_MEM, parse_tag_rsvd_mem);
375 
376 static int __init parse_tag_cmdline(struct tag *tag)
377 {
379  return 0;
380 }
381 __tagtable(ATAG_CMDLINE, parse_tag_cmdline);
382 
383 static int __init parse_tag_clock(struct tag *tag)
384 {
385  /*
386  * We'll figure out the clocks by peeking at the system
387  * manager regs directly.
388  */
389  return 0;
390 }
391 __tagtable(ATAG_CLOCK, parse_tag_clock);
392 
393 /*
394  * The board_number correspond to the bd->bi_board_number in U-Boot. This
395  * parameter is only available during initialisation and can be used in some
396  * kind of board identification.
397  */
399 
400 static int __init parse_tag_boardinfo(struct tag *tag)
401 {
402  board_number = tag->u.boardinfo.board_number;
403 
404  return 0;
405 }
406 __tagtable(ATAG_BOARDINFO, parse_tag_boardinfo);
407 
408 /*
409  * Scan the tag table for this tag, and call its parse function. The
410  * tag table is built by the linker from all the __tagtable
411  * declarations.
412  */
413 static int __init parse_tag(struct tag *tag)
414 {
415  extern struct tagtable __tagtable_begin, __tagtable_end;
416  struct tagtable *t;
417 
418  for (t = &__tagtable_begin; t < &__tagtable_end; t++)
419  if (tag->hdr.tag == t->tag) {
420  t->parse(tag);
421  break;
422  }
423 
424  return t < &__tagtable_end;
425 }
426 
427 /*
428  * Parse all tags in the list we got from the boot loader
429  */
430 static void __init parse_tags(struct tag *t)
431 {
432  for (; t->hdr.tag != ATAG_NONE; t = tag_next(t))
433  if (!parse_tag(t))
435  "Ignoring unrecognised tag 0x%08x\n",
436  t->hdr.tag);
437 }
438 
439 /*
440  * Find a free memory region large enough for storing the
441  * bootmem bitmap.
442  */
443 static unsigned long __init
444 find_bootmap_pfn(const struct resource *mem)
445 {
446  unsigned long bootmap_pages, bootmap_len;
447  unsigned long node_pages = PFN_UP(resource_size(mem));
448  unsigned long bootmap_start;
449 
450  bootmap_pages = bootmem_bootmap_pages(node_pages);
451  bootmap_len = bootmap_pages << PAGE_SHIFT;
452 
453  /*
454  * Find a large enough region without reserved pages for
455  * storing the bootmem bitmap. We can take advantage of the
456  * fact that all lists have been sorted.
457  *
458  * We have to check that we don't collide with any reserved
459  * regions, which includes the kernel image and any RAMDISK
460  * images.
461  */
462  bootmap_start = find_free_region(mem, bootmap_len, PAGE_SIZE);
463 
464  return bootmap_start >> PAGE_SHIFT;
465 }
466 
467 #define MAX_LOWMEM HIGHMEM_START
468 #define MAX_LOWMEM_PFN PFN_DOWN(MAX_LOWMEM)
469 
470 static void __init setup_bootmem(void)
471 {
472  unsigned bootmap_size;
473  unsigned long first_pfn, bootmap_pfn, pages;
474  unsigned long max_pfn, max_low_pfn;
475  unsigned node = 0;
476  struct resource *res;
477 
478  printk(KERN_INFO "Physical memory:\n");
479  for (res = system_ram; res; res = res->sibling)
480  printk(" %08x-%08x\n", res->start, res->end);
481  printk(KERN_INFO "Reserved memory:\n");
482  for (res = reserved; res; res = res->sibling)
483  printk(" %08x-%08x: %s\n",
484  res->start, res->end, res->name);
485 
487 
488  if (system_ram->sibling)
489  printk(KERN_WARNING "Only using first memory bank\n");
490 
491  for (res = system_ram; res; res = NULL) {
492  first_pfn = PFN_UP(res->start);
493  max_low_pfn = max_pfn = PFN_DOWN(res->end + 1);
494  bootmap_pfn = find_bootmap_pfn(res);
495  if (bootmap_pfn > max_pfn)
496  panic("No space for bootmem bitmap!\n");
497 
498  if (max_low_pfn > MAX_LOWMEM_PFN) {
499  max_low_pfn = MAX_LOWMEM_PFN;
500 #ifndef CONFIG_HIGHMEM
501  /*
502  * Lowmem is memory that can be addressed
503  * directly through P1/P2
504  */
506  "Node %u: Only %ld MiB of memory will be used.\n",
507  node, MAX_LOWMEM >> 20);
508  printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
509 #else
510 #error HIGHMEM is not supported by AVR32 yet
511 #endif
512  }
513 
514  /* Initialize the boot-time allocator with low memory only. */
515  bootmap_size = init_bootmem_node(NODE_DATA(node), bootmap_pfn,
516  first_pfn, max_low_pfn);
517 
518  /*
519  * Register fully available RAM pages with the bootmem
520  * allocator.
521  */
522  pages = max_low_pfn - first_pfn;
523  free_bootmem_node (NODE_DATA(node), PFN_PHYS(first_pfn),
524  PFN_PHYS(pages));
525 
526  /* Reserve space for the bootmem bitmap... */
528  PFN_PHYS(bootmap_pfn),
529  bootmap_size,
531 
532  /* ...and any other reserved regions. */
533  for (res = reserved; res; res = res->sibling) {
534  if (res->start > PFN_PHYS(max_pfn))
535  break;
536 
537  /*
538  * resource_init will complain about partial
539  * overlaps, so we'll just ignore such
540  * resources for now.
541  */
542  if (res->start >= PFN_PHYS(first_pfn)
543  && res->end < PFN_PHYS(max_pfn))
545  res->start,
546  resource_size(res),
548  }
549 
550  node_set_online(node);
551  }
552 }
553 
554 void __init setup_arch (char **cmdline_p)
555 {
556  struct clk *cpu_clk;
557 
558  init_mm.start_code = (unsigned long)_text;
559  init_mm.end_code = (unsigned long)_etext;
560  init_mm.end_data = (unsigned long)_edata;
561  init_mm.brk = (unsigned long)_end;
562 
563  /*
564  * Include .init section to make allocations easier. It will
565  * be removed before the resource is actually requested.
566  */
567  kernel_code.start = __pa(__init_begin);
568  kernel_code.end = __pa(init_mm.end_code - 1);
569  kernel_data.start = __pa(init_mm.end_code);
570  kernel_data.end = __pa(init_mm.brk - 1);
571 
572  parse_tags(bootloader_tags);
573 
574  setup_processor();
575  setup_platform();
576  setup_board();
577 
578  cpu_clk = clk_get(NULL, "cpu");
579  if (IS_ERR(cpu_clk)) {
580  printk(KERN_WARNING "Warning: Unable to get CPU clock\n");
581  } else {
582  unsigned long cpu_hz = clk_get_rate(cpu_clk);
583 
584  /*
585  * Well, duh, but it's probably a good idea to
586  * increment the use count.
587  */
588  clk_enable(cpu_clk);
589 
590  boot_cpu_data.clk = cpu_clk;
591  boot_cpu_data.loops_per_jiffy = cpu_hz * 4;
592  printk("CPU: Running at %lu.%03lu MHz\n",
593  ((cpu_hz + 500) / 1000) / 1000,
594  ((cpu_hz + 500) / 1000) % 1000);
595  }
596 
598  *cmdline_p = command_line;
600 
601  setup_bootmem();
602 
603 #ifdef CONFIG_VT
605 #endif
606 
607  paging_init();
608  resource_init();
609 }