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 - PAGE_OFFSET) >> 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(zones_size);
  64 }
  65
  66 asmlinkage void __init init_pda(void)
  67 {
  68         unsigned int cpu = raw_smp_processor_id();
  69
  70         early_shadow_stamp();
  71
  72         /* Initialize the PDA fields holding references to other parts
  73            of the memory. The content of such memory is still
  74            undefined at the time of the call, we are only setting up
  75            valid pointers to it. */
  76         memset(&cpu_pda[cpu], 0, sizeof(cpu_pda[cpu]));
  77
  78         cpu_pda[0].next = &cpu_pda[1];
  79         cpu_pda[1].next = &cpu_pda[0];
  80
  81 #ifdef CONFIG_EXCEPTION_L1_SCRATCH
  82         cpu_pda[cpu].ex_stack = (unsigned long *)(L1_SCRATCH_START + \
  83                                         L1_SCRATCH_LENGTH);
  84 #else
  85         cpu_pda[cpu].ex_stack = exception_stack[cpu + 1];
  86 #endif
  87
  88 #ifdef CONFIG_SMP
  89         cpu_pda[cpu].imask = 0x1f;
  90 #endif
  91 }
  92
  93 void __init mem_init(void)
  94 {
  95         unsigned int codek = 0, datak = 0, initk = 0;
  96         unsigned int reservedpages = 0, freepages = 0;
  97         unsigned long tmp;
  98         unsigned long start_mem = memory_start;
  99         unsigned long end_mem = memory_end;
 100
 101         end_mem &= PAGE_MASK;
 102         high_memory = (void *)end_mem;
 103
 104         start_mem = PAGE_ALIGN(start_mem);
 105         max_mapnr = num_physpages = MAP_NR(high_memory);
 106         printk(KERN_DEBUG "Kernel managed physical pages: %lu\n", num_physpages);
 107
 108         /* This will put all memory onto the freelists. */
 109         totalram_pages = free_all_bootmem();
 110
 111         reservedpages = 0;
 112         for (tmp = 0; tmp < max_mapnr; tmp++)
 113                 if (PageReserved(pfn_to_page(tmp)))
 114                         reservedpages++;
 115         freepages =  max_mapnr - reservedpages;
 116
 117         /* do not count in kernel image between _rambase and _ramstart */
 118         reservedpages -= (_ramstart - _rambase) >> PAGE_SHIFT;
 119 #if (defined(CONFIG_BFIN_EXTMEM_ICACHEABLE) && ANOMALY_05000263)
 120         reservedpages += (_ramend - memory_end - DMA_UNCACHED_REGION) >> PAGE_SHIFT;
 121 #endif
 122
 123         codek = (_etext - _stext) >> 10;
 124         initk = (__init_end - __init_begin) >> 10;
 125         datak = ((_ramstart - _rambase) >> 10) - codek - initk;
 126
 127         printk(KERN_INFO
 128              "Memory available: %luk/%luk RAM, "
 129                 "(%uk init code, %uk kernel code, %uk data, %uk dma, %uk reserved)\n",
 130                 (unsigned long) freepages << (PAGE_SHIFT-10), _ramend >> 10,
 131                 initk, codek, datak, DMA_UNCACHED_REGION >> 10, (reservedpages << (PAGE_SHIFT-10)));
 132 }
 133
 134 static void __init free_init_pages(const char *what, unsigned long begin, unsigned long end)
 135 {
 136         unsigned long addr;
 137         /* next to check that the page we free is not a partial page */
 138         for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
 139                 ClearPageReserved(virt_to_page(addr));
 140                 init_page_count(virt_to_page(addr));
 141                 free_page(addr);
 142                 totalram_pages++;
 143         }
 144         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 145 }
 146
 147 #ifdef CONFIG_BLK_DEV_INITRD
 148 void __init free_initrd_mem(unsigned long start, unsigned long end)
 149 {
 150 #ifndef CONFIG_MPU
 151         free_init_pages("initrd memory", start, end);
 152 #endif
 153 }
 154 #endif
 155
 156 void __init_refok free_initmem(void)
 157 {
 158 #if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
 159         free_init_pages("unused kernel memory",
 160                         (unsigned long)(&__init_begin),
 161                         (unsigned long)(&__init_end));
 162
 163         if (memory_start == (unsigned long)(&__init_end))
 164                 memory_start = (unsigned long)(&__init_begin);
 165 #endif
 166 }