linux/arch/avr32/kernel/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
  32extern int root_mountflags;
  33
  34/*
  35 * Initialize loops_per_jiffy as 5000000 (500MIPS).
  36 * Better make it too large than too small...
  37 */
  38struct avr32_cpuinfo boot_cpu_data = {
  39        .loops_per_jiffy = 5000000
  40};
  41EXPORT_SYMBOL(boot_cpu_data);
  42
  43static char __initdata command_line[COMMAND_LINE_SIZE];
  44
  45/*
  46 * Standard memory resources
  47 */
  48static struct resource __initdata kernel_data = {
  49        .name   = "Kernel data",
  50        .start  = 0,
  51        .end    = 0,
  52        .flags  = IORESOURCE_MEM,
  53};
  54static 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 */
  67static struct resource *__initdata system_ram;
  68static 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 */
  75static struct resource __initdata res_cache[32];
  76static unsigned int __initdata res_cache_next_free;
  77
  78static 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;
  90                if (request_resource(&iomem_resource, new))
  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))
 101                        printk(KERN_WARNING
 102                               "Bad reserved resource %s (%08x-%08x)\n",
 103                               res->name, res->start, res->end);
 104        }
 105}
 106
 107static void __init
 108add_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) {
 117                        printk(KERN_WARNING
 118                               "Warning: Physical memory map is broken\n");
 119                        printk(KERN_WARNING
 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)) {
 127                printk(KERN_WARNING
 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
 142static int __init
 143add_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
 174static unsigned long __init
 175find_free_region(const struct resource *mem, resource_size_t size,
 176                 resource_size_t align)
 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
 195static int __init
 196alloc_reserved_region(resource_size_t *start, resource_size_t size,
 197                      resource_size_t align, const char *name)
 198{
 199        struct resource *mem;
 200        resource_size_t target;
 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 */
 232resource_size_t __initdata fbmem_start;
 233resource_size_t __initdata fbmem_size;
 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 */
 245static 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) {
 257                        printk(KERN_WARNING
 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) {
 274                        printk(KERN_WARNING
 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}
 284early_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 */
 290static int __init early_mem(char *p)
 291{
 292        resource_size_t size, start;
 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}
 303early_param("mem", early_mem);
 304
 305static int __init parse_tag_core(struct tag *tag)
 306{
 307        if (tag->hdr.size > 2) {
 308                if ((tag->u.core.flags & 1) == 0)
 309                        root_mountflags &= ~MS_RDONLY;
 310                ROOT_DEV = new_decode_dev(tag->u.core.rootdev);
 311        }
 312        return 0;
 313}
 314__tagtable(ATAG_CORE, parse_tag_core);
 315
 316static 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
 336static 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) {
 343                printk(KERN_WARNING
 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) {
 351                printk(KERN_WARNING
 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
 367static 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
 376static int __init parse_tag_cmdline(struct tag *tag)
 377{
 378        strlcpy(boot_command_line, tag->u.cmdline.cmdline, COMMAND_LINE_SIZE);
 379        return 0;
 380}
 381__tagtable(ATAG_CMDLINE, parse_tag_cmdline);
 382
 383static 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 */
 398u32 __initdata board_number;
 399
 400static 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 */
 413static 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 */
 430static void __init parse_tags(struct tag *t)
 431{
 432        for (; t->hdr.tag != ATAG_NONE; t = tag_next(t))
 433                if (!parse_tag(t))
 434                        printk(KERN_WARNING
 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 */
 443static unsigned long __init
 444find_bootmap_pfn(const struct resource *mem)
 445{
 446        unsigned long bootmap_pages, bootmap_len;
 447        unsigned long node_pages = PFN_UP(mem->end - mem->start + 1);
 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
 470static 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
 486        nodes_clear(node_online_map);
 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                         */
 505                        printk(KERN_WARNING
 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... */
 527                reserve_bootmem_node(NODE_DATA(node),
 528                                     PFN_PHYS(bootmap_pfn),
 529                                     bootmap_size,
 530                                     BOOTMEM_DEFAULT);
 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))
 544                                reserve_bootmem_node(
 545                                        NODE_DATA(node), res->start,
 546                                        res->end - res->start + 1,
 547                                        BOOTMEM_DEFAULT);
 548                }
 549
 550                node_set_online(node);
 551        }
 552}
 553
 554void __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
 597        strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
 598        *cmdline_p = command_line;
 599        parse_early_param();
 600
 601        setup_bootmem();
 602
 603#ifdef CONFIG_VT
 604        conswitchp = &dummy_con;
 605#endif
 606
 607        paging_init();
 608        resource_init();
 609}
 610