arch/blackfin/mm/init.c

   1 /*
   2  * File:         arch/blackfin/mm/init.c
   3  * Based on:
   4  * Author:
   5  *
   6  * Created:
   7  * Description:
   8  *
   9  * Modified:
  10  *               Copyright 2004-2007 Analog Devices Inc.
  11  *
  12  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, see the file COPYING, or write
  26  * to the Free Software Foundation, Inc.,
  27  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  28  */
  29
  30 #include <linux/swap.h>
  31 #include <linux/bootmem.h>
  32 #include <linux/uaccess.h>
  33 #include <asm/bfin-global.h>
  34 #include <asm/pda.h>
  35 #include <asm/cplbinit.h>
  36 #include "blackfin_sram.h"
  37
  38 /*
  39  * BAD_PAGE is the page that is used for page faults when linux
  40  * is out-of-memory. Older versions of linux just did a
  41  * do_exit(), but using this instead means there is less risk
  42  * for a process dying in kernel mode, possibly leaving a inode
  43  * unused etc..
  44  *
  45  * BAD_PAGETABLE is the accompanying page-table: it is initialized
  46  * to point to BAD_PAGE entries.
  47  *
  48  * ZERO_PAGE is a special page that is used for zero-initialized
  49  * data and COW.
  50  */
  51 static unsigned long empty_bad_page_table;
  52
  53 static unsigned long empty_bad_page;
  54
  55 unsigned long empty_zero_page;
  56
  57 extern unsigned long exception_stack[NR_CPUS][1024];
  58
  59 struct blackfin_pda cpu_pda[NR_CPUS];
  60 EXPORT_SYMBOL(cpu_pda);
  61
  62 /*
  63  * paging_init() continues the virtual memory environment setup which
  64  * was begun by the code in arch/head.S.
  65  * The parameters are pointers to where to stick the starting and ending
  66  * addresses  of available kernel virtual memory.
  67  */
  68 void __init paging_init(void)
  69 {
  70         /*
  71          * make sure start_mem is page aligned,  otherwise bootmem and
  72          * page_alloc get different views og the world
  73          */
  74         unsigned long end_mem = memory_end & PAGE_MASK;
  75
  76         pr_debug("start_mem is %#lx   virtual_end is %#lx\n", PAGE_ALIGN(memory_start), end_mem);
  77
  78         /*
  79          * initialize the bad page table and bad page to point
  80          * to a couple of allocated pages
  81          */
  82         empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  83         empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  84         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  85         memset((void *)empty_zero_page, 0, PAGE_SIZE);
  86
  87         /*
  88          * Set up SFC/DFC registers (user data space)
  89          */
  90         set_fs(KERNEL_DS);
  91
  92         pr_debug("free_area_init -> start_mem is %#lx   virtual_end is %#lx\n",
  93                 PAGE_ALIGN(memory_start), end_mem);
  94
  95         {
  96                 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
  97
  98                 zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
  99                 zones_size[ZONE_NORMAL] = 0;
 100 #ifdef CONFIG_HIGHMEM
 101                 zones_size[ZONE_HIGHMEM] = 0;
 102 #endif
 103                 free_area_init(zones_size);
 104         }
 105 }
 106
 107 asmlinkage void __init init_pda(void)
 108 {
 109         unsigned int cpu = raw_smp_processor_id();
 110
 111         /* Initialize the PDA fields holding references to other parts
 112            of the memory. The content of such memory is still
 113            undefined at the time of the call, we are only setting up
 114            valid pointers to it. */
 115         memset(&cpu_pda[cpu], 0, sizeof(cpu_pda[cpu]));
 116
 117         cpu_pda[0].next = &cpu_pda[1];
 118         cpu_pda[1].next = &cpu_pda[0];
 119
 120         cpu_pda[cpu].ex_stack = exception_stack[cpu + 1];
 121
 122 #ifdef CONFIG_SMP
 123         cpu_pda[cpu].imask = 0x1f;
 124 #endif
 125 }
 126
 127 void __cpuinit reserve_pda(void)
 128 {
 129         printk(KERN_INFO "PDA for CPU%u reserved at %p\n", smp_processor_id(),
 130                                         &cpu_pda[smp_processor_id()]);
 131 }
 132
 133 void __init mem_init(void)
 134 {
 135         unsigned int codek = 0, datak = 0, initk = 0;
 136         unsigned int reservedpages = 0, freepages = 0;
 137         unsigned long tmp;
 138         unsigned long start_mem = memory_start;
 139         unsigned long end_mem = memory_end;
 140
 141         end_mem &= PAGE_MASK;
 142         high_memory = (void *)end_mem;
 143
 144         start_mem = PAGE_ALIGN(start_mem);
 145         max_mapnr = num_physpages = MAP_NR(high_memory);
 146         printk(KERN_DEBUG "Kernel managed physical pages: %lu\n", num_physpages);
 147
 148         /* This will put all memory onto the freelists. */
 149         totalram_pages = free_all_bootmem();
 150
 151         reservedpages = 0;
 152         for (tmp = 0; tmp < max_mapnr; tmp++)
 153                 if (PageReserved(pfn_to_page(tmp)))
 154                         reservedpages++;
 155         freepages =  max_mapnr - reservedpages;
 156
 157         /* do not count in kernel image between _rambase and _ramstart */
 158         reservedpages -= (_ramstart - _rambase) >> PAGE_SHIFT;
 159 #if (defined(CONFIG_BFIN_ICACHE) && ANOMALY_05000263)
 160         reservedpages += (_ramend - memory_end - DMA_UNCACHED_REGION) >> PAGE_SHIFT;
 161 #endif
 162
 163         codek = (_etext - _stext) >> 10;
 164         initk = (__init_end - __init_begin) >> 10;
 165         datak = ((_ramstart - _rambase) >> 10) - codek - initk;
 166
 167         printk(KERN_INFO
 168              "Memory available: %luk/%luk RAM, "
 169                 "(%uk init code, %uk kernel code, %uk data, %uk dma, %uk reserved)\n",
 170                 (unsigned long) freepages << (PAGE_SHIFT-10), _ramend >> 10,
 171                 initk, codek, datak, DMA_UNCACHED_REGION >> 10, (reservedpages << (PAGE_SHIFT-10)));
 172 }
 173
 174 static int __init sram_init(void)
 175 {
 176         /* Initialize the blackfin L1 Memory. */
 177         bfin_sram_init();
 178
 179         /* Reserve the PDA space for the boot CPU right after we
 180          * initialized the scratch memory allocator.
 181          */
 182         reserve_pda();
 183         return 0;
 184 }
 185 pure_initcall(sram_init);
 186
 187 static void __init free_init_pages(const char *what, unsigned long begin, unsigned long end)
 188 {
 189         unsigned long addr;
 190         /* next to check that the page we free is not a partial page */
 191         for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
 192                 ClearPageReserved(virt_to_page(addr));
 193                 init_page_count(virt_to_page(addr));
 194                 free_page(addr);
 195                 totalram_pages++;
 196         }
 197         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 198 }
 199
 200 #ifdef CONFIG_BLK_DEV_INITRD
 201 void __init free_initrd_mem(unsigned long start, unsigned long end)
 202 {
 203 #ifndef CONFIG_MPU
 204         free_init_pages("initrd memory", start, end);
 205 #endif
 206 }
 207 #endif
 208
 209 void __init_refok free_initmem(void)
 210 {
 211 #if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
 212         free_init_pages("unused kernel memory",
 213                         (unsigned long)(&__init_begin),
 214                         (unsigned long)(&__init_end));
 215 #endif
 216 }