root/arch/microblaze/mm/init.c

DEFINITIONS

1. virt_to_kpte
2. highmem_init
3. highmem_setup
4. paging_init
5. setup_memory
6. mem_init
7. page_is_ram
8. page_is_ram
9. mm_cmdline_setup
10. mmu_init_hw
11. mmu_init
12. early_get_page
13. zalloc_maybe_bootmem

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