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 <linux/export.h>
  12 #include <asm/bfin-global.h>
  13 #include <asm/pda.h>
  14 #include <asm/cplbinit.h>
  15 #include <asm/early_printk.h>
  16 #include "blackfin_sram.h"
  17
  18 /*
  19  * ZERO_PAGE is a special page that is used for zero-initialized data and COW.
  20  * Let the bss do its zero-init magic so we don't have to do it ourselves.
  21  */
  22 char empty_zero_page[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
  23 EXPORT_SYMBOL(empty_zero_page);
  24
  25 #ifndef CONFIG_EXCEPTION_L1_SCRATCH
  26 #if defined CONFIG_SYSCALL_TAB_L1
  27 __attribute__((l1_data))
  28 #endif
  29 static unsigned long exception_stack[NR_CPUS][1024];
  30 #endif
  31
  32 struct blackfin_pda cpu_pda[NR_CPUS];
  33 EXPORT_SYMBOL(cpu_pda);
  34
  35 /*
  36  * paging_init() continues the virtual memory environment setup which
  37  * was begun by the code in arch/head.S.
  38  * The parameters are pointers to where to stick the starting and ending
  39  * addresses  of available kernel virtual memory.
  40  */
  41 void __init paging_init(void)
  42 {
  43         /*
  44          * make sure start_mem is page aligned, otherwise bootmem and
  45          * page_alloc get different views of the world
  46          */
  47         unsigned long end_mem = memory_end & PAGE_MASK;
  48
  49         unsigned long zones_size[MAX_NR_ZONES] = {
  50                 [0] = 0,
  51                 [ZONE_DMA] = (end_mem - CONFIG_PHY_RAM_BASE_ADDRESS) >> PAGE_SHIFT,
  52                 [ZONE_NORMAL] = 0,
  53 #ifdef CONFIG_HIGHMEM
  54                 [ZONE_HIGHMEM] = 0,
  55 #endif
  56         };
  57
  58         /* Set up SFC/DFC registers (user data space) */
  59         set_fs(KERNEL_DS);
  60
  61         pr_debug("free_area_init -> start_mem is %#lx virtual_end is %#lx\n",
  62                 PAGE_ALIGN(memory_start), end_mem);
  63         free_area_init_node(0, zones_size,
  64                 CONFIG_PHY_RAM_BASE_ADDRESS >> PAGE_SHIFT, NULL);
  65 }
  66
  67 asmlinkage void __init init_pda(void)
  68 {
  69         unsigned int cpu = raw_smp_processor_id();
  70
  71         early_shadow_stamp();
  72
  73         /* Initialize the PDA fields holding references to other parts
  74            of the memory. The content of such memory is still
  75            undefined at the time of the call, we are only setting up
  76            valid pointers to it. */
  77         memset(&cpu_pda[cpu], 0, sizeof(cpu_pda[cpu]));
  78
  79 #ifdef CONFIG_EXCEPTION_L1_SCRATCH
  80         cpu_pda[cpu].ex_stack = (unsigned long *)(L1_SCRATCH_START + \
  81                                         L1_SCRATCH_LENGTH);
  82 #else
  83         cpu_pda[cpu].ex_stack = exception_stack[cpu + 1];
  84 #endif
  85
  86 #ifdef CONFIG_SMP
  87         cpu_pda[cpu].imask = 0x1f;
  88 #endif
  89 }
  90
  91 void __init mem_init(void)
  92 {
  93         char buf[64];
  94
  95         high_memory = (void *)(memory_end & PAGE_MASK);
  96         max_mapnr = MAP_NR(high_memory);
  97         printk(KERN_DEBUG "Kernel managed physical pages: %lu\n", max_mapnr);
  98
  99         /* This will put all low memory onto the freelists. */
 100         free_all_bootmem();
 101
 102         snprintf(buf, sizeof(buf) - 1, "%uK DMA", DMA_UNCACHED_REGION >> 10);
 103         mem_init_print_info(buf);
 104 }
 105
 106 #ifdef CONFIG_BLK_DEV_INITRD
 107 void __init free_initrd_mem(unsigned long start, unsigned long end)
 108 {
 109 #ifndef CONFIG_MPU
 110         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 111 #endif
 112 }
 113 #endif
 114
 115 void __ref free_initmem(void)
 116 {
 117 #if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
 118         free_initmem_default(-1);
 119         if (memory_start == (unsigned long)(&__init_end))
 120                 memory_start = (unsigned long)(&__init_begin);
 121 #endif
 122 }