arch/microblaze/mm/init.c

   1 /*
   2  * Copyright (C) 2007-2008 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2006 Atmark Techno, Inc.
   4  *
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License. See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  */
   9
  10 #include <linux/bootmem.h>
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/memblock.h>
  14 #include <linux/mm.h> /* mem_init */
  15 #include <linux/initrd.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/pfn.h>
  18 #include <linux/slab.h>
  19 #include <linux/swap.h>
  20 #include <linux/export.h>
  21
  22 #include <asm/page.h>
  23 #include <asm/mmu_context.h>
  24 #include <asm/pgalloc.h>
  25 #include <asm/sections.h>
  26 #include <asm/tlb.h>
  27 #include <asm/fixmap.h>
  28
  29 /* Use for MMU and noMMU because of PCI generic code */
  30 int mem_init_done;
  31
  32 #ifndef CONFIG_MMU
  33 unsigned int __page_offset;
  34 EXPORT_SYMBOL(__page_offset);
  35 #endif /* CONFIG_MMU */
  36
  37 char *klimit = _end;
  38
  39 /*
  40  * Initialize the bootmem system and give it all the memory we
  41  * have available.
  42  */
  43 unsigned long memory_start;
  44 EXPORT_SYMBOL(memory_start);
  45 unsigned long memory_size;
  46 EXPORT_SYMBOL(memory_size);
  47 unsigned long lowmem_size;
  48
  49 #ifdef CONFIG_HIGHMEM
  50 pte_t *kmap_pte;
  51 EXPORT_SYMBOL(kmap_pte);
  52 pgprot_t kmap_prot;
  53 EXPORT_SYMBOL(kmap_prot);
  54
  55 static inline pte_t *virt_to_kpte(unsigned long vaddr)
  56 {
  57         return pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr),
  58                         vaddr), vaddr);
  59 }
  60
  61 static void __init highmem_init(void)
  62 {
  63         pr_debug("%x\n", (u32)PKMAP_BASE);
  64         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
  65         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
  66
  67         kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
  68         kmap_prot = PAGE_KERNEL;
  69 }
  70
  71 static void highmem_setup(void)
  72 {
  73         unsigned long pfn;
  74
  75         for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
  76                 struct page *page = pfn_to_page(pfn);
  77
  78                 /* FIXME not sure about */
  79                 if (!memblock_is_reserved(pfn << PAGE_SHIFT))
  80                         free_highmem_page(page);
  81         }
  82 }
  83 #endif /* CONFIG_HIGHMEM */
  84
  85 /*
  86  * paging_init() sets up the page tables - in fact we've already done this.
  87  */
  88 static void __init paging_init(void)
  89 {
  90         unsigned long zones_size[MAX_NR_ZONES];
  91 #ifdef CONFIG_MMU
  92         int idx;
  93
  94         /* Setup fixmaps */
  95         for (idx = 0; idx < __end_of_fixed_addresses; idx++)
  96                 clear_fixmap(idx);
  97 #endif
  98
  99         /* Clean every zones */
 100         memset(zones_size, 0, sizeof(zones_size));
 101
 102 #ifdef CONFIG_HIGHMEM
 103         highmem_init();
 104
 105         zones_size[ZONE_DMA] = max_low_pfn;
 106         zones_size[ZONE_HIGHMEM] = max_pfn;
 107 #else
 108         zones_size[ZONE_DMA] = max_pfn;
 109 #endif
 110
 111         /* We don't have holes in memory map */
 112         free_area_init_nodes(zones_size);
 113 }
 114
 115 void __init setup_memory(void)
 116 {
 117         struct memblock_region *reg;
 118
 119 #ifndef CONFIG_MMU
 120         u32 kernel_align_start, kernel_align_size;
 121
 122         /* Find main memory where is the kernel */
 123         for_each_memblock(memory, reg) {
 124                 memory_start = (u32)reg->base;
 125                 lowmem_size = reg->size;
 126                 if ((memory_start <= (u32)_text) &&
 127                         ((u32)_text <= (memory_start + lowmem_size - 1))) {
 128                         memory_size = lowmem_size;
 129                         PAGE_OFFSET = memory_start;
 130                         pr_info("%s: Main mem: 0x%x, size 0x%08x\n",
 131                                 __func__, (u32) memory_start,
 132                                         (u32) memory_size);
 133                         break;
 134                 }
 135         }
 136
 137         if (!memory_start || !memory_size) {
 138                 panic("%s: Missing memory setting 0x%08x, size=0x%08x\n",
 139                         __func__, (u32) memory_start, (u32) memory_size);
 140         }
 141
 142         /* reservation of region where is the kernel */
 143         kernel_align_start = PAGE_DOWN((u32)_text);
 144         /* ALIGN can be remove because _end in vmlinux.lds.S is align */
 145         kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start;
 146         pr_info("%s: kernel addr:0x%08x-0x%08x size=0x%08x\n",
 147                 __func__, kernel_align_start, kernel_align_start
 148                         + kernel_align_size, kernel_align_size);
 149         memblock_reserve(kernel_align_start, kernel_align_size);
 150 #endif
 151         /*
 152          * Kernel:
 153          * start: base phys address of kernel - page align
 154          * end: base phys address of kernel - page align
 155          *
 156          * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
 157          * max_low_pfn
 158          * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
 159          */
 160
 161         /* memory start is from the kernel end (aligned) to higher addr */
 162         min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
 163         /* RAM is assumed contiguous */
 164         max_mapnr = memory_size >> PAGE_SHIFT;
 165         max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
 166         max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
 167
 168         pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
 169         pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
 170         pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
 171         pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
 172
 173         /* Add active regions with valid PFNs */
 174         for_each_memblock(memory, reg) {
 175                 unsigned long start_pfn, end_pfn;
 176
 177                 start_pfn = memblock_region_memory_base_pfn(reg);
 178                 end_pfn = memblock_region_memory_end_pfn(reg);
 179                 memblock_set_node(start_pfn << PAGE_SHIFT,
 180                                   (end_pfn - start_pfn) << PAGE_SHIFT,
 181                                   &memblock.memory, 0);
 182         }
 183
 184         /* XXX need to clip this if using highmem? */
 185         sparse_memory_present_with_active_regions(0);
 186
 187         paging_init();
 188 }
 189
 190 #ifdef CONFIG_BLK_DEV_INITRD
 191 void free_initrd_mem(unsigned long start, unsigned long end)
 192 {
 193         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 194 }
 195 #endif
 196
 197 void free_initmem(void)
 198 {
 199         free_initmem_default(-1);
 200 }
 201
 202 void __init mem_init(void)
 203 {
 204         high_memory = (void *)__va(memory_start + lowmem_size - 1);
 205
 206         /* this will put all memory onto the freelists */
 207         free_all_bootmem();
 208 #ifdef CONFIG_HIGHMEM
 209         highmem_setup();
 210 #endif
 211
 212         mem_init_print_info(NULL);
 213 #ifdef CONFIG_MMU
 214         pr_info("Kernel virtual memory layout:\n");
 215         pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
 216 #ifdef CONFIG_HIGHMEM
 217         pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
 218                 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
 219 #endif /* CONFIG_HIGHMEM */
 220         pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
 221                 ioremap_bot, ioremap_base);
 222         pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
 223                 (unsigned long)VMALLOC_START, VMALLOC_END);
 224 #endif
 225         mem_init_done = 1;
 226 }
 227
 228 #ifndef CONFIG_MMU
 229 int page_is_ram(unsigned long pfn)
 230 {
 231         return __range_ok(pfn, 0);
 232 }
 233 #else
 234 int page_is_ram(unsigned long pfn)
 235 {
 236         return pfn < max_low_pfn;
 237 }
 238
 239 /*
 240  * Check for command-line options that affect what MMU_init will do.
 241  */
 242 static void mm_cmdline_setup(void)
 243 {
 244         unsigned long maxmem = 0;
 245         char *p = cmd_line;
 246
 247         /* Look for mem= option on command line */
 248         p = strstr(cmd_line, "mem=");
 249         if (p) {
 250                 p += 4;
 251                 maxmem = memparse(p, &p);
 252                 if (maxmem && memory_size > maxmem) {
 253                         memory_size = maxmem;
 254                         memblock.memory.regions[0].size = memory_size;
 255                 }
 256         }
 257 }
 258
 259 /*
 260  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 261  */
 262 static void __init mmu_init_hw(void)
 263 {
 264         /*
 265          * The Zone Protection Register (ZPR) defines how protection will
 266          * be applied to every page which is a member of a given zone. At
 267          * present, we utilize only two of the zones.
 268          * The zone index bits (of ZSEL) in the PTE are used for software
 269          * indicators, except the LSB.  For user access, zone 1 is used,
 270          * for kernel access, zone 0 is used.  We set all but zone 1
 271          * to zero, allowing only kernel access as indicated in the PTE.
 272          * For zone 1, we set a 01 binary (a value of 10 will not work)
 273          * to allow user access as indicated in the PTE.  This also allows
 274          * kernel access as indicated in the PTE.
 275          */
 276         __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
 277                         "mts rzpr, r11;"
 278                         : : : "r11");
 279 }
 280
 281 /*
 282  * MMU_init sets up the basic memory mappings for the kernel,
 283  * including both RAM and possibly some I/O regions,
 284  * and sets up the page tables and the MMU hardware ready to go.
 285  */
 286
 287 /* called from head.S */
 288 asmlinkage void __init mmu_init(void)
 289 {
 290         unsigned int kstart, ksize;
 291
 292         if (!memblock.reserved.cnt) {
 293                 pr_emerg("Error memory count\n");
 294                 machine_restart(NULL);
 295         }
 296
 297         if ((u32) memblock.memory.regions[0].size < 0x400000) {
 298                 pr_emerg("Memory must be greater than 4MB\n");
 299                 machine_restart(NULL);
 300         }
 301
 302         if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
 303                 pr_emerg("Kernel size is greater than memory node\n");
 304                 machine_restart(NULL);
 305         }
 306
 307         /* Find main memory where the kernel is */
 308         memory_start = (u32) memblock.memory.regions[0].base;
 309         lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
 310
 311         if (lowmem_size > CONFIG_LOWMEM_SIZE) {
 312                 lowmem_size = CONFIG_LOWMEM_SIZE;
 313 #ifndef CONFIG_HIGHMEM
 314                 memory_size = lowmem_size;
 315 #endif
 316         }
 317
 318         mm_cmdline_setup(); /* FIXME parse args from command line - not used */
 319
 320         /*
 321          * Map out the kernel text/data/bss from the available physical
 322          * memory.
 323          */
 324         kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
 325         /* kernel size */
 326         ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
 327         memblock_reserve(kstart, ksize);
 328
 329 #if defined(CONFIG_BLK_DEV_INITRD)
 330         /* Remove the init RAM disk from the available memory. */
 331         if (initrd_start) {
 332                 unsigned long size;
 333                 size = initrd_end - initrd_start;
 334                 memblock_reserve(__virt_to_phys(initrd_start), size);
 335         }
 336 #endif /* CONFIG_BLK_DEV_INITRD */
 337
 338         /* Initialize the MMU hardware */
 339         mmu_init_hw();
 340
 341         /* Map in all of RAM starting at CONFIG_KERNEL_START */
 342         mapin_ram();
 343
 344         /* Extend vmalloc and ioremap area as big as possible */
 345 #ifdef CONFIG_HIGHMEM
 346         ioremap_base = ioremap_bot = PKMAP_BASE;
 347 #else
 348         ioremap_base = ioremap_bot = FIXADDR_START;
 349 #endif
 350
 351         /* Initialize the context management stuff */
 352         mmu_context_init();
 353
 354         /* Shortly after that, the entire linear mapping will be available */
 355         /* This will also cause that unflatten device tree will be allocated
 356          * inside 768MB limit */
 357         memblock_set_current_limit(memory_start + lowmem_size - 1);
 358 }
 359
 360 /* This is only called until mem_init is done. */
 361 void __init *early_get_page(void)
 362 {
 363         /*
 364          * Mem start + kernel_tlb -> here is limit
 365          * because of mem mapping from head.S
 366          */
 367         return __va(memblock_alloc_base(PAGE_SIZE, PAGE_SIZE,
 368                                 memory_start + kernel_tlb));
 369 }
 370
 371 #endif /* CONFIG_MMU */
 372
 373 void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
 374 {
 375         void *p;
 376
 377         if (mem_init_done)
 378                 p = kzalloc(size, mask);
 379         else {
 380                 p = alloc_bootmem(size);
 381                 if (p)
 382                         memset(p, 0, size);
 383         }
 384         return p;
 385 }