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/dma-map-ops.h>
  11 #include <linux/memblock.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.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 char *klimit = _end;
  33
  34 /*
  35  * Initialize the bootmem system and give it all the memory we
  36  * have available.
  37  */
  38 unsigned long memory_start;
  39 EXPORT_SYMBOL(memory_start);
  40 unsigned long memory_size;
  41 EXPORT_SYMBOL(memory_size);
  42 unsigned long lowmem_size;
  43
  44 EXPORT_SYMBOL(min_low_pfn);
  45 EXPORT_SYMBOL(max_low_pfn);
  46
  47 #ifdef CONFIG_HIGHMEM
  48 static void __init highmem_init(void)
  49 {
  50         pr_debug("%x\n", (u32)PKMAP_BASE);
  51         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
  52         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
  53 }
  54
  55 static void highmem_setup(void)
  56 {
  57         unsigned long pfn;
  58
  59         for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
  60                 struct page *page = pfn_to_page(pfn);
  61
  62                 /* FIXME not sure about */
  63                 if (!memblock_is_reserved(pfn << PAGE_SHIFT))
  64                         free_highmem_page(page);
  65         }
  66 }
  67 #endif /* CONFIG_HIGHMEM */
  68
  69 /*
  70  * paging_init() sets up the page tables - in fact we've already done this.
  71  */
  72 static void __init paging_init(void)
  73 {
  74         unsigned long zones_size[MAX_NR_ZONES];
  75         int idx;
  76
  77         /* Setup fixmaps */
  78         for (idx = 0; idx < __end_of_fixed_addresses; idx++)
  79                 clear_fixmap(idx);
  80
  81         /* Clean every zones */
  82         memset(zones_size, 0, sizeof(zones_size));
  83
  84 #ifdef CONFIG_HIGHMEM
  85         highmem_init();
  86
  87         zones_size[ZONE_DMA] = max_low_pfn;
  88         zones_size[ZONE_HIGHMEM] = max_pfn;
  89 #else
  90         zones_size[ZONE_DMA] = max_pfn;
  91 #endif
  92
  93         /* We don't have holes in memory map */
  94         free_area_init(zones_size);
  95 }
  96
  97 void __init setup_memory(void)
  98 {
  99         /*
 100          * Kernel:
 101          * start: base phys address of kernel - page align
 102          * end: base phys address of kernel - page align
 103          *
 104          * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
 105          * max_low_pfn
 106          * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
 107          */
 108
 109         /* memory start is from the kernel end (aligned) to higher addr */
 110         min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
 111         /* RAM is assumed contiguous */
 112         max_mapnr = memory_size >> PAGE_SHIFT;
 113         max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
 114         max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
 115
 116         pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
 117         pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
 118         pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
 119         pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
 120
 121         paging_init();
 122 }
 123
 124 void __init mem_init(void)
 125 {
 126         high_memory = (void *)__va(memory_start + lowmem_size - 1);
 127
 128         /* this will put all memory onto the freelists */
 129         memblock_free_all();
 130 #ifdef CONFIG_HIGHMEM
 131         highmem_setup();
 132 #endif
 133
 134         mem_init_print_info(NULL);
 135         mem_init_done = 1;
 136 }
 137
 138 int page_is_ram(unsigned long pfn)
 139 {
 140         return pfn < max_low_pfn;
 141 }
 142
 143 /*
 144  * Check for command-line options that affect what MMU_init will do.
 145  */
 146 static void mm_cmdline_setup(void)
 147 {
 148         unsigned long maxmem = 0;
 149         char *p = cmd_line;
 150
 151         /* Look for mem= option on command line */
 152         p = strstr(cmd_line, "mem=");
 153         if (p) {
 154                 p += 4;
 155                 maxmem = memparse(p, &p);
 156                 if (maxmem && memory_size > maxmem) {
 157                         memory_size = maxmem;
 158                         memblock.memory.regions[0].size = memory_size;
 159                 }
 160         }
 161 }
 162
 163 /*
 164  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 165  */
 166 static void __init mmu_init_hw(void)
 167 {
 168         /*
 169          * The Zone Protection Register (ZPR) defines how protection will
 170          * be applied to every page which is a member of a given zone. At
 171          * present, we utilize only two of the zones.
 172          * The zone index bits (of ZSEL) in the PTE are used for software
 173          * indicators, except the LSB.  For user access, zone 1 is used,
 174          * for kernel access, zone 0 is used.  We set all but zone 1
 175          * to zero, allowing only kernel access as indicated in the PTE.
 176          * For zone 1, we set a 01 binary (a value of 10 will not work)
 177          * to allow user access as indicated in the PTE.  This also allows
 178          * kernel access as indicated in the PTE.
 179          */
 180         __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
 181                         "mts rzpr, r11;"
 182                         : : : "r11");
 183 }
 184
 185 /*
 186  * MMU_init sets up the basic memory mappings for the kernel,
 187  * including both RAM and possibly some I/O regions,
 188  * and sets up the page tables and the MMU hardware ready to go.
 189  */
 190
 191 /* called from head.S */
 192 asmlinkage void __init mmu_init(void)
 193 {
 194         unsigned int kstart, ksize;
 195
 196         if (!memblock.reserved.cnt) {
 197                 pr_emerg("Error memory count\n");
 198                 machine_restart(NULL);
 199         }
 200
 201         if ((u32) memblock.memory.regions[0].size < 0x400000) {
 202                 pr_emerg("Memory must be greater than 4MB\n");
 203                 machine_restart(NULL);
 204         }
 205
 206         if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
 207                 pr_emerg("Kernel size is greater than memory node\n");
 208                 machine_restart(NULL);
 209         }
 210
 211         /* Find main memory where the kernel is */
 212         memory_start = (u32) memblock.memory.regions[0].base;
 213         lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
 214
 215         if (lowmem_size > CONFIG_LOWMEM_SIZE) {
 216                 lowmem_size = CONFIG_LOWMEM_SIZE;
 217 #ifndef CONFIG_HIGHMEM
 218                 memory_size = lowmem_size;
 219 #endif
 220         }
 221
 222         mm_cmdline_setup(); /* FIXME parse args from command line - not used */
 223
 224         /*
 225          * Map out the kernel text/data/bss from the available physical
 226          * memory.
 227          */
 228         kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
 229         /* kernel size */
 230         ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
 231         memblock_reserve(kstart, ksize);
 232
 233 #if defined(CONFIG_BLK_DEV_INITRD)
 234         /* Remove the init RAM disk from the available memory. */
 235         if (initrd_start) {
 236                 unsigned long size;
 237                 size = initrd_end - initrd_start;
 238                 memblock_reserve(__virt_to_phys(initrd_start), size);
 239         }
 240 #endif /* CONFIG_BLK_DEV_INITRD */
 241
 242         /* Initialize the MMU hardware */
 243         mmu_init_hw();
 244
 245         /* Map in all of RAM starting at CONFIG_KERNEL_START */
 246         mapin_ram();
 247
 248         /* Extend vmalloc and ioremap area as big as possible */
 249 #ifdef CONFIG_HIGHMEM
 250         ioremap_base = ioremap_bot = PKMAP_BASE;
 251 #else
 252         ioremap_base = ioremap_bot = FIXADDR_START;
 253 #endif
 254
 255         /* Initialize the context management stuff */
 256         mmu_context_init();
 257
 258         /* Shortly after that, the entire linear mapping will be available */
 259         /* This will also cause that unflatten device tree will be allocated
 260          * inside 768MB limit */
 261         memblock_set_current_limit(memory_start + lowmem_size - 1);
 262
 263         parse_early_param();
 264
 265         /* CMA initialization */
 266         dma_contiguous_reserve(memory_start + lowmem_size - 1);
 267 }
 268
 269 /* This is only called until mem_init is done. */
 270 void __init *early_get_page(void)
 271 {
 272         /*
 273          * Mem start + kernel_tlb -> here is limit
 274          * because of mem mapping from head.S
 275          */
 276         return memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE,
 277                                 MEMBLOCK_LOW_LIMIT, memory_start + kernel_tlb,
 278                                 NUMA_NO_NODE);
 279 }
 280
 281 void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
 282 {
 283         void *p;
 284
 285         if (mem_init_done) {
 286                 p = kzalloc(size, mask);
 287         } else {
 288                 p = memblock_alloc(size, SMP_CACHE_BYTES);
 289                 if (!p)
 290                         panic("%s: Failed to allocate %zu bytes\n",
 291                               __func__, size);
 292         }
 293
 294         return p;
 295 }