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/of_fdt.h>
  17 #include <linux/pagemap.h>
  18 #include <linux/pfn.h>
  19 #include <linux/slab.h>
  20 #include <linux/swap.h>
  21 #include <linux/export.h>
  22
  23 #include <asm/page.h>
  24 #include <asm/mmu_context.h>
  25 #include <asm/pgalloc.h>
  26 #include <asm/sections.h>
  27 #include <asm/tlb.h>
  28 #include <asm/fixmap.h>
  29
  30 /* Use for MMU and noMMU because of PCI generic code */
  31 int mem_init_done;
  32
  33 char *klimit = _end;
  34
  35 /*
  36  * Initialize the bootmem system and give it all the memory we
  37  * have available.
  38  */
  39 unsigned long memory_start;
  40 EXPORT_SYMBOL(memory_start);
  41 unsigned long memory_size;
  42 EXPORT_SYMBOL(memory_size);
  43 unsigned long lowmem_size;
  44
  45 EXPORT_SYMBOL(min_low_pfn);
  46 EXPORT_SYMBOL(max_low_pfn);
  47
  48 #ifdef CONFIG_HIGHMEM
  49 static void __init highmem_init(void)
  50 {
  51         pr_debug("%x\n", (u32)PKMAP_BASE);
  52         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
  53         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
  54 }
  55
  56 static void __meminit highmem_setup(void)
  57 {
  58         unsigned long pfn;
  59
  60         for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
  61                 struct page *page = pfn_to_page(pfn);
  62
  63                 /* FIXME not sure about */
  64                 if (!memblock_is_reserved(pfn << PAGE_SHIFT))
  65                         free_highmem_page(page);
  66         }
  67 }
  68 #endif /* CONFIG_HIGHMEM */
  69
  70 /*
  71  * paging_init() sets up the page tables - in fact we've already done this.
  72  */
  73 static void __init paging_init(void)
  74 {
  75         unsigned long zones_size[MAX_NR_ZONES];
  76         int idx;
  77
  78         /* Setup fixmaps */
  79         for (idx = 0; idx < __end_of_fixed_addresses; idx++)
  80                 clear_fixmap(idx);
  81
  82         /* Clean every zones */
  83         memset(zones_size, 0, sizeof(zones_size));
  84
  85 #ifdef CONFIG_HIGHMEM
  86         highmem_init();
  87
  88         zones_size[ZONE_DMA] = max_low_pfn;
  89         zones_size[ZONE_HIGHMEM] = max_pfn;
  90 #else
  91         zones_size[ZONE_DMA] = max_pfn;
  92 #endif
  93
  94         /* We don't have holes in memory map */
  95         free_area_init(zones_size);
  96 }
  97
  98 void __init setup_memory(void)
  99 {
 100         /*
 101          * Kernel:
 102          * start: base phys address of kernel - page align
 103          * end: base phys address of kernel - page align
 104          *
 105          * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
 106          * max_low_pfn
 107          * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
 108          */
 109
 110         /* memory start is from the kernel end (aligned) to higher addr */
 111         min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
 112         /* RAM is assumed contiguous */
 113         max_mapnr = memory_size >> PAGE_SHIFT;
 114         max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
 115         max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
 116
 117         pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
 118         pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
 119         pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
 120         pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
 121
 122         paging_init();
 123 }
 124
 125 void __init mem_init(void)
 126 {
 127         high_memory = (void *)__va(memory_start + lowmem_size - 1);
 128
 129         /* this will put all memory onto the freelists */
 130         memblock_free_all();
 131 #ifdef CONFIG_HIGHMEM
 132         highmem_setup();
 133 #endif
 134
 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 ((u32) memblock.memory.regions[0].size < 0x400000) {
 197                 pr_emerg("Memory must be greater than 4MB\n");
 198                 machine_restart(NULL);
 199         }
 200
 201         if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
 202                 pr_emerg("Kernel size is greater than memory node\n");
 203                 machine_restart(NULL);
 204         }
 205
 206         /* Find main memory where the kernel is */
 207         memory_start = (u32) memblock.memory.regions[0].base;
 208         lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
 209
 210         if (lowmem_size > CONFIG_LOWMEM_SIZE) {
 211                 lowmem_size = CONFIG_LOWMEM_SIZE;
 212 #ifndef CONFIG_HIGHMEM
 213                 memory_size = lowmem_size;
 214 #endif
 215         }
 216
 217         mm_cmdline_setup(); /* FIXME parse args from command line - not used */
 218
 219         /*
 220          * Map out the kernel text/data/bss from the available physical
 221          * memory.
 222          */
 223         kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
 224         /* kernel size */
 225         ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
 226         memblock_reserve(kstart, ksize);
 227
 228 #if defined(CONFIG_BLK_DEV_INITRD)
 229         /* Remove the init RAM disk from the available memory. */
 230         if (initrd_start) {
 231                 unsigned long size;
 232                 size = initrd_end - initrd_start;
 233                 memblock_reserve(__virt_to_phys(initrd_start), size);
 234         }
 235 #endif /* CONFIG_BLK_DEV_INITRD */
 236
 237         /* Initialize the MMU hardware */
 238         mmu_init_hw();
 239
 240         /* Map in all of RAM starting at CONFIG_KERNEL_START */
 241         mapin_ram();
 242
 243         /* Extend vmalloc and ioremap area as big as possible */
 244 #ifdef CONFIG_HIGHMEM
 245         ioremap_base = ioremap_bot = PKMAP_BASE;
 246 #else
 247         ioremap_base = ioremap_bot = FIXADDR_START;
 248 #endif
 249
 250         /* Initialize the context management stuff */
 251         mmu_context_init();
 252
 253         /* Shortly after that, the entire linear mapping will be available */
 254         /* This will also cause that unflatten device tree will be allocated
 255          * inside 768MB limit */
 256         memblock_set_current_limit(memory_start + lowmem_size - 1);
 257
 258         parse_early_param();
 259
 260         early_init_fdt_scan_reserved_mem();
 261
 262         /* CMA initialization */
 263         dma_contiguous_reserve(memory_start + lowmem_size - 1);
 264
 265         memblock_dump_all();
 266 }
 267
 268 static const pgprot_t protection_map[16] = {
 269         [VM_NONE]                                       = PAGE_NONE,
 270         [VM_READ]                                       = PAGE_READONLY_X,
 271         [VM_WRITE]                                      = PAGE_COPY,
 272         [VM_WRITE | VM_READ]                            = PAGE_COPY_X,
 273         [VM_EXEC]                                       = PAGE_READONLY,
 274         [VM_EXEC | VM_READ]                             = PAGE_READONLY_X,
 275         [VM_EXEC | VM_WRITE]                            = PAGE_COPY,
 276         [VM_EXEC | VM_WRITE | VM_READ]                  = PAGE_COPY_X,
 277         [VM_SHARED]                                     = PAGE_NONE,
 278         [VM_SHARED | VM_READ]                           = PAGE_READONLY_X,
 279         [VM_SHARED | VM_WRITE]                          = PAGE_SHARED,
 280         [VM_SHARED | VM_WRITE | VM_READ]                = PAGE_SHARED_X,
 281         [VM_SHARED | VM_EXEC]                           = PAGE_READONLY,
 282         [VM_SHARED | VM_EXEC | VM_READ]                 = PAGE_READONLY_X,
 283         [VM_SHARED | VM_EXEC | VM_WRITE]                = PAGE_SHARED,
 284         [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]      = PAGE_SHARED_X
 285 };
 286 DECLARE_VM_GET_PAGE_PROT