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