arch/blackfin/mm/init.c

   1 /*
   2  * Copyright 2004-2009 Analog Devices Inc.
   3  *
   4  * Licensed under the GPL-2 or later.
   5  */
   6
   7 #include <linux/swap.h>
   8 #include <linux/bootmem.h>
   9 #include <linux/uaccess.h>
  10 #include <asm/bfin-global.h>
  11 #include <asm/pda.h>
  12 #include <asm/cplbinit.h>
  13 #include <asm/early_printk.h>
  14 #include "blackfin_sram.h"
  15
  16 /*
  17  * BAD_PAGE is the page that is used for page faults when linux
  18  * is out-of-memory. Older versions of linux just did a
  19  * do_exit(), but using this instead means there is less risk
  20  * for a process dying in kernel mode, possibly leaving a inode
  21  * unused etc..
  22  *
  23  * BAD_PAGETABLE is the accompanying page-table: it is initialized
  24  * to point to BAD_PAGE entries.
  25  *
  26  * ZERO_PAGE is a special page that is used for zero-initialized
  27  * data and COW.
  28  */
  29 static unsigned long empty_bad_page_table;
  30
  31 static unsigned long empty_bad_page;
  32
  33 static unsigned long empty_zero_page;
  34
  35 #ifndef CONFIG_EXCEPTION_L1_SCRATCH
  36 #if defined CONFIG_SYSCALL_TAB_L1
  37 __attribute__((l1_data))
  38 #endif
  39 static unsigned long exception_stack[NR_CPUS][1024];
  40 #endif
  41
  42 struct blackfin_pda cpu_pda[NR_CPUS];
  43 EXPORT_SYMBOL(cpu_pda);
  44
  45 /*
  46  * paging_init() continues the virtual memory environment setup which
  47  * was begun by the code in arch/head.S.
  48  * The parameters are pointers to where to stick the starting and ending
  49  * addresses  of available kernel virtual memory.
  50  */
  51 void __init paging_init(void)
  52 {
  53         /*
  54          * make sure start_mem is page aligned,  otherwise bootmem and
  55          * page_alloc get different views og the world
  56          */
  57         unsigned long end_mem = memory_end & PAGE_MASK;
  58
  59         pr_debug("start_mem is %#lx   virtual_end is %#lx\n", PAGE_ALIGN(memory_start), end_mem);
  60
  61         /*
  62          * initialize the bad page table and bad page to point
  63          * to a couple of allocated pages
  64          */
  65         empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  66         empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  67         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  68         memset((void *)empty_zero_page, 0, PAGE_SIZE);
  69
  70         /*
  71          * Set up SFC/DFC registers (user data space)
  72          */
  73         set_fs(KERNEL_DS);
  74
  75         pr_debug("free_area_init -> start_mem is %#lx   virtual_end is %#lx\n",
  76                 PAGE_ALIGN(memory_start), end_mem);
  77
  78         {
  79                 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
  80
  81                 zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
  82                 zones_size[ZONE_NORMAL] = 0;
  83 #ifdef CONFIG_HIGHMEM
  84                 zones_size[ZONE_HIGHMEM] = 0;
  85 #endif
  86                 free_area_init(zones_size);
  87         }
  88 }
  89
  90 asmlinkage void __init init_pda(void)
  91 {
  92         unsigned int cpu = raw_smp_processor_id();
  93
  94         early_shadow_stamp();
  95
  96         /* Initialize the PDA fields holding references to other parts
  97            of the memory. The content of such memory is still
  98            undefined at the time of the call, we are only setting up
  99            valid pointers to it. */
 100         memset(&cpu_pda[cpu], 0, sizeof(cpu_pda[cpu]));
 101
 102         cpu_pda[0].next = &cpu_pda[1];
 103         cpu_pda[1].next = &cpu_pda[0];
 104
 105 #ifdef CONFIG_EXCEPTION_L1_SCRATCH
 106         cpu_pda[cpu].ex_stack = (unsigned long *)(L1_SCRATCH_START + \
 107                                         L1_SCRATCH_LENGTH);
 108 #else
 109         cpu_pda[cpu].ex_stack = exception_stack[cpu + 1];
 110 #endif
 111
 112 #ifdef CONFIG_SMP
 113         cpu_pda[cpu].imask = 0x1f;
 114 #endif
 115 }
 116
 117 void __init mem_init(void)
 118 {
 119         unsigned int codek = 0, datak = 0, initk = 0;
 120         unsigned int reservedpages = 0, freepages = 0;
 121         unsigned long tmp;
 122         unsigned long start_mem = memory_start;
 123         unsigned long end_mem = memory_end;
 124
 125         end_mem &= PAGE_MASK;
 126         high_memory = (void *)end_mem;
 127
 128         start_mem = PAGE_ALIGN(start_mem);
 129         max_mapnr = num_physpages = MAP_NR(high_memory);
 130         printk(KERN_DEBUG "Kernel managed physical pages: %lu\n", num_physpages);
 131
 132         /* This will put all memory onto the freelists. */
 133         totalram_pages = free_all_bootmem();
 134
 135         reservedpages = 0;
 136         for (tmp = 0; tmp < max_mapnr; tmp++)
 137                 if (PageReserved(pfn_to_page(tmp)))
 138                         reservedpages++;
 139         freepages =  max_mapnr - reservedpages;
 140
 141         /* do not count in kernel image between _rambase and _ramstart */
 142         reservedpages -= (_ramstart - _rambase) >> PAGE_SHIFT;
 143 #if (defined(CONFIG_BFIN_EXTMEM_ICACHEABLE) && ANOMALY_05000263)
 144         reservedpages += (_ramend - memory_end - DMA_UNCACHED_REGION) >> PAGE_SHIFT;
 145 #endif
 146
 147         codek = (_etext - _stext) >> 10;
 148         initk = (__init_end - __init_begin) >> 10;
 149         datak = ((_ramstart - _rambase) >> 10) - codek - initk;
 150
 151         printk(KERN_INFO
 152              "Memory available: %luk/%luk RAM, "
 153                 "(%uk init code, %uk kernel code, %uk data, %uk dma, %uk reserved)\n",
 154                 (unsigned long) freepages << (PAGE_SHIFT-10), _ramend >> 10,
 155                 initk, codek, datak, DMA_UNCACHED_REGION >> 10, (reservedpages << (PAGE_SHIFT-10)));
 156 }
 157
 158 static void __init free_init_pages(const char *what, unsigned long begin, unsigned long end)
 159 {
 160         unsigned long addr;
 161         /* next to check that the page we free is not a partial page */
 162         for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
 163                 ClearPageReserved(virt_to_page(addr));
 164                 init_page_count(virt_to_page(addr));
 165                 free_page(addr);
 166                 totalram_pages++;
 167         }
 168         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 169 }
 170
 171 #ifdef CONFIG_BLK_DEV_INITRD
 172 void __init free_initrd_mem(unsigned long start, unsigned long end)
 173 {
 174 #ifndef CONFIG_MPU
 175         free_init_pages("initrd memory", start, end);
 176 #endif
 177 }
 178 #endif
 179
 180 void __init_refok free_initmem(void)
 181 {
 182 #if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
 183         free_init_pages("unused kernel memory",
 184                         (unsigned long)(&__init_begin),
 185                         (unsigned long)(&__init_end));
 186 #endif
 187 }