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 static unsigned long empty_zero_page;
  56
  57 #ifndef CONFIG_EXCEPTION_L1_SCRATCH
  58 #if defined CONFIG_SYSCALL_TAB_L1
  59 __attribute__((l1_data))
  60 #endif
  61 static unsigned long exception_stack[NR_CPUS][1024];
  62 #endif
  63
  64 struct blackfin_pda cpu_pda[NR_CPUS];
  65 EXPORT_SYMBOL(cpu_pda);
  66
  67 /*
  68  * paging_init() continues the virtual memory environment setup which
  69  * was begun by the code in arch/head.S.
  70  * The parameters are pointers to where to stick the starting and ending
  71  * addresses  of available kernel virtual memory.
  72  */
  73 void __init paging_init(void)
  74 {
  75         /*
  76          * make sure start_mem is page aligned,  otherwise bootmem and
  77          * page_alloc get different views og the world
  78          */
  79         unsigned long end_mem = memory_end & PAGE_MASK;
  80
  81         pr_debug("start_mem is %#lx   virtual_end is %#lx\n", PAGE_ALIGN(memory_start), end_mem);
  82
  83         /*
  84          * initialize the bad page table and bad page to point
  85          * to a couple of allocated pages
  86          */
  87         empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  88         empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  89         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  90         memset((void *)empty_zero_page, 0, PAGE_SIZE);
  91
  92         /*
  93          * Set up SFC/DFC registers (user data space)
  94          */
  95         set_fs(KERNEL_DS);
  96
  97         pr_debug("free_area_init -> start_mem is %#lx   virtual_end is %#lx\n",
  98                 PAGE_ALIGN(memory_start), end_mem);
  99
 100         {
 101                 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
 102
 103                 zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
 104                 zones_size[ZONE_NORMAL] = 0;
 105 #ifdef CONFIG_HIGHMEM
 106                 zones_size[ZONE_HIGHMEM] = 0;
 107 #endif
 108                 free_area_init(zones_size);
 109         }
 110 }
 111
 112 asmlinkage void __init init_pda(void)
 113 {
 114         unsigned int cpu = raw_smp_processor_id();
 115
 116         /* Initialize the PDA fields holding references to other parts
 117            of the memory. The content of such memory is still
 118            undefined at the time of the call, we are only setting up
 119            valid pointers to it. */
 120         memset(&cpu_pda[cpu], 0, sizeof(cpu_pda[cpu]));
 121
 122         cpu_pda[0].next = &cpu_pda[1];
 123         cpu_pda[1].next = &cpu_pda[0];
 124
 125 #ifdef CONFIG_EXCEPTION_L1_SCRATCH
 126         cpu_pda[cpu].ex_stack = (unsigned long *)(L1_SCRATCH_START + \
 127                                         L1_SCRATCH_LENGTH);
 128 #else
 129         cpu_pda[cpu].ex_stack = exception_stack[cpu + 1];
 130 #endif
 131
 132 #ifdef CONFIG_SMP
 133         cpu_pda[cpu].imask = 0x1f;
 134 #endif
 135 }
 136
 137 void __init mem_init(void)
 138 {
 139         unsigned int codek = 0, datak = 0, initk = 0;
 140         unsigned int reservedpages = 0, freepages = 0;
 141         unsigned long tmp;
 142         unsigned long start_mem = memory_start;
 143         unsigned long end_mem = memory_end;
 144
 145         end_mem &= PAGE_MASK;
 146         high_memory = (void *)end_mem;
 147
 148         start_mem = PAGE_ALIGN(start_mem);
 149         max_mapnr = num_physpages = MAP_NR(high_memory);
 150         printk(KERN_DEBUG "Kernel managed physical pages: %lu\n", num_physpages);
 151
 152         /* This will put all memory onto the freelists. */
 153         totalram_pages = free_all_bootmem();
 154
 155         reservedpages = 0;
 156         for (tmp = 0; tmp < max_mapnr; tmp++)
 157                 if (PageReserved(pfn_to_page(tmp)))
 158                         reservedpages++;
 159         freepages =  max_mapnr - reservedpages;
 160
 161         /* do not count in kernel image between _rambase and _ramstart */
 162         reservedpages -= (_ramstart - _rambase) >> PAGE_SHIFT;
 163 #if (defined(CONFIG_BFIN_EXTMEM_ICACHEABLE) && ANOMALY_05000263)
 164         reservedpages += (_ramend - memory_end - DMA_UNCACHED_REGION) >> PAGE_SHIFT;
 165 #endif
 166
 167         codek = (_etext - _stext) >> 10;
 168         initk = (__init_end - __init_begin) >> 10;
 169         datak = ((_ramstart - _rambase) >> 10) - codek - initk;
 170
 171         printk(KERN_INFO
 172              "Memory available: %luk/%luk RAM, "
 173                 "(%uk init code, %uk kernel code, %uk data, %uk dma, %uk reserved)\n",
 174                 (unsigned long) freepages << (PAGE_SHIFT-10), _ramend >> 10,
 175                 initk, codek, datak, DMA_UNCACHED_REGION >> 10, (reservedpages << (PAGE_SHIFT-10)));
 176 }
 177
 178 static void __init free_init_pages(const char *what, unsigned long begin, unsigned long end)
 179 {
 180         unsigned long addr;
 181         /* next to check that the page we free is not a partial page */
 182         for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
 183                 ClearPageReserved(virt_to_page(addr));
 184                 init_page_count(virt_to_page(addr));
 185                 free_page(addr);
 186                 totalram_pages++;
 187         }
 188         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 189 }
 190
 191 #ifdef CONFIG_BLK_DEV_INITRD
 192 void __init free_initrd_mem(unsigned long start, unsigned long end)
 193 {
 194 #ifndef CONFIG_MPU
 195         free_init_pages("initrd memory", start, end);
 196 #endif
 197 }
 198 #endif
 199
 200 void __init_refok free_initmem(void)
 201 {
 202 #if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
 203         free_init_pages("unused kernel memory",
 204                         (unsigned long)(&__init_begin),
 205                         (unsigned long)(&__init_end));
 206 #endif
 207 }