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         unsigned int codek = 0, datak = 0, initk = 0;
  94         unsigned int reservedpages = 0, freepages = 0;
  95         unsigned long tmp;
  96         unsigned long start_mem = memory_start;
  97         unsigned long end_mem = memory_end;
  98
  99         end_mem &= PAGE_MASK;
 100         high_memory = (void *)end_mem;
 101
 102         start_mem = PAGE_ALIGN(start_mem);
 103         max_mapnr = num_physpages = MAP_NR(high_memory);
 104         printk(KERN_DEBUG "Kernel managed physical pages: %lu\n", num_physpages);
 105
 106         /* This will put all low memory onto the freelists. */
 107         totalram_pages = free_all_bootmem();
 108
 109         reservedpages = 0;
 110         for (tmp = ARCH_PFN_OFFSET; tmp < max_mapnr; tmp++)
 111                 if (PageReserved(pfn_to_page(tmp)))
 112                         reservedpages++;
 113         freepages =  max_mapnr - ARCH_PFN_OFFSET - reservedpages;
 114
 115         /* do not count in kernel image between _rambase and _ramstart */
 116         reservedpages -= (_ramstart - _rambase) >> PAGE_SHIFT;
 117 #if (defined(CONFIG_BFIN_EXTMEM_ICACHEABLE) && ANOMALY_05000263)
 118         reservedpages += (_ramend - memory_end - DMA_UNCACHED_REGION) >> PAGE_SHIFT;
 119 #endif
 120
 121         codek = (_etext - _stext) >> 10;
 122         initk = (__init_end - __init_begin) >> 10;
 123         datak = ((_ramstart - _rambase) >> 10) - codek - initk;
 124
 125         printk(KERN_INFO
 126              "Memory available: %luk/%luk RAM, "
 127                 "(%uk init code, %uk kernel code, %uk data, %uk dma, %uk reserved)\n",
 128                 (unsigned long) freepages << (PAGE_SHIFT-10), (_ramend - CONFIG_PHY_RAM_BASE_ADDRESS) >> 10,
 129                 initk, codek, datak, DMA_UNCACHED_REGION >> 10, (reservedpages << (PAGE_SHIFT-10)));
 130 }
 131
 132 #ifdef CONFIG_BLK_DEV_INITRD
 133 void __init free_initrd_mem(unsigned long start, unsigned long end)
 134 {
 135 #ifndef CONFIG_MPU
 136         free_reserved_area(start, end, 0, "initrd");
 137 #endif
 138 }
 139 #endif
 140
 141 void __init_refok free_initmem(void)
 142 {
 143 #if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
 144         free_initmem_default(0);
 145         if (memory_start == (unsigned long)(&__init_end))
 146                 memory_start = (unsigned long)(&__init_begin);
 147 #endif
 148 }