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/gfp.h>
   8 #include <linux/swap.h>
   9 #include <linux/bootmem.h>
  10 #include <linux/uaccess.h>
  11 #include <asm/bfin-global.h>
  12 #include <asm/pda.h>
  13 #include <asm/cplbinit.h>
  14 #include <asm/early_printk.h>
  15 #include "blackfin_sram.h"
  16
  17 /*
  18  * BAD_PAGE is the page that is used for page faults when linux
  19  * is out-of-memory. Older versions of linux just did a
  20  * do_exit(), but using this instead means there is less risk
  21  * for a process dying in kernel mode, possibly leaving a inode
  22  * unused etc..
  23  *
  24  * BAD_PAGETABLE is the accompanying page-table: it is initialized
  25  * to point to BAD_PAGE entries.
  26  *
  27  * ZERO_PAGE is a special page that is used for zero-initialized
  28  * data and COW.
  29  */
  30 static unsigned long empty_bad_page_table;
  31
  32 static unsigned long empty_bad_page;
  33
  34 static unsigned long empty_zero_page;
  35
  36 #ifndef CONFIG_EXCEPTION_L1_SCRATCH
  37 #if defined CONFIG_SYSCALL_TAB_L1
  38 __attribute__((l1_data))
  39 #endif
  40 static unsigned long exception_stack[NR_CPUS][1024];
  41 #endif
  42
  43 struct blackfin_pda cpu_pda[NR_CPUS];
  44 EXPORT_SYMBOL(cpu_pda);
  45
  46 /*
  47  * paging_init() continues the virtual memory environment setup which
  48  * was begun by the code in arch/head.S.
  49  * The parameters are pointers to where to stick the starting and ending
  50  * addresses  of available kernel virtual memory.
  51  */
  52 void __init paging_init(void)
  53 {
  54         /*
  55          * make sure start_mem is page aligned,  otherwise bootmem and
  56          * page_alloc get different views og the world
  57          */
  58         unsigned long end_mem = memory_end & PAGE_MASK;
  59
  60         pr_debug("start_mem is %#lx   virtual_end is %#lx\n", PAGE_ALIGN(memory_start), end_mem);
  61
  62         /*
  63          * initialize the bad page table and bad page to point
  64          * to a couple of allocated pages
  65          */
  66         empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  67         empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  68         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  69         memset((void *)empty_zero_page, 0, PAGE_SIZE);
  70
  71         /*
  72          * Set up SFC/DFC registers (user data space)
  73          */
  74         set_fs(KERNEL_DS);
  75
  76         pr_debug("free_area_init -> start_mem is %#lx   virtual_end is %#lx\n",
  77                 PAGE_ALIGN(memory_start), end_mem);
  78
  79         {
  80                 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
  81
  82                 zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
  83                 zones_size[ZONE_NORMAL] = 0;
  84 #ifdef CONFIG_HIGHMEM
  85                 zones_size[ZONE_HIGHMEM] = 0;
  86 #endif
  87                 free_area_init(zones_size);
  88         }
  89 }
  90
  91 asmlinkage void __init init_pda(void)
  92 {
  93         unsigned int cpu = raw_smp_processor_id();
  94
  95         early_shadow_stamp();
  96
  97         /* Initialize the PDA fields holding references to other parts
  98            of the memory. The content of such memory is still
  99            undefined at the time of the call, we are only setting up
 100            valid pointers to it. */
 101         memset(&cpu_pda[cpu], 0, sizeof(cpu_pda[cpu]));
 102
 103         cpu_pda[0].next = &cpu_pda[1];
 104         cpu_pda[1].next = &cpu_pda[0];
 105
 106 #ifdef CONFIG_EXCEPTION_L1_SCRATCH
 107         cpu_pda[cpu].ex_stack = (unsigned long *)(L1_SCRATCH_START + \
 108                                         L1_SCRATCH_LENGTH);
 109 #else
 110         cpu_pda[cpu].ex_stack = exception_stack[cpu + 1];
 111 #endif
 112
 113 #ifdef CONFIG_SMP
 114         cpu_pda[cpu].imask = 0x1f;
 115 #endif
 116 }
 117
 118 void __init mem_init(void)
 119 {
 120         unsigned int codek = 0, datak = 0, initk = 0;
 121         unsigned int reservedpages = 0, freepages = 0;
 122         unsigned long tmp;
 123         unsigned long start_mem = memory_start;
 124         unsigned long end_mem = memory_end;
 125
 126         end_mem &= PAGE_MASK;
 127         high_memory = (void *)end_mem;
 128
 129         start_mem = PAGE_ALIGN(start_mem);
 130         max_mapnr = num_physpages = MAP_NR(high_memory);
 131         printk(KERN_DEBUG "Kernel managed physical pages: %lu\n", num_physpages);
 132
 133         /* This will put all memory onto the freelists. */
 134         totalram_pages = free_all_bootmem();
 135
 136         reservedpages = 0;
 137         for (tmp = 0; tmp < max_mapnr; tmp++)
 138                 if (PageReserved(pfn_to_page(tmp)))
 139                         reservedpages++;
 140         freepages =  max_mapnr - reservedpages;
 141
 142         /* do not count in kernel image between _rambase and _ramstart */
 143         reservedpages -= (_ramstart - _rambase) >> PAGE_SHIFT;
 144 #if (defined(CONFIG_BFIN_EXTMEM_ICACHEABLE) && ANOMALY_05000263)
 145         reservedpages += (_ramend - memory_end - DMA_UNCACHED_REGION) >> PAGE_SHIFT;
 146 #endif
 147
 148         codek = (_etext - _stext) >> 10;
 149         initk = (__init_end - __init_begin) >> 10;
 150         datak = ((_ramstart - _rambase) >> 10) - codek - initk;
 151
 152         printk(KERN_INFO
 153              "Memory available: %luk/%luk RAM, "
 154                 "(%uk init code, %uk kernel code, %uk data, %uk dma, %uk reserved)\n",
 155                 (unsigned long) freepages << (PAGE_SHIFT-10), _ramend >> 10,
 156                 initk, codek, datak, DMA_UNCACHED_REGION >> 10, (reservedpages << (PAGE_SHIFT-10)));
 157 }
 158
 159 static void __init free_init_pages(const char *what, unsigned long begin, unsigned long end)
 160 {
 161         unsigned long addr;
 162         /* next to check that the page we free is not a partial page */
 163         for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
 164                 ClearPageReserved(virt_to_page(addr));
 165                 init_page_count(virt_to_page(addr));
 166                 free_page(addr);
 167                 totalram_pages++;
 168         }
 169         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 170 }
 171
 172 #ifdef CONFIG_BLK_DEV_INITRD
 173 void __init free_initrd_mem(unsigned long start, unsigned long end)
 174 {
 175 #ifndef CONFIG_MPU
 176         free_init_pages("initrd memory", start, end);
 177 #endif
 178 }
 179 #endif
 180
 181 void __init_refok free_initmem(void)
 182 {
 183 #if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
 184         free_init_pages("unused kernel memory",
 185                         (unsigned long)(&__init_begin),
 186                         (unsigned long)(&__init_end));
 187 #endif
 188 }