arch/alpha/mm/init.c

/* */
This source file includes following definitions.
__bad_pagetable
__bad_page
show_mem
load_PCB
paging_init
mem_init
si_meminfo
   1 /*
   2  *  linux/arch/alpha/mm/init.c
   3  *
   4  *  Copyright (C) 1995  Linus Torvalds
   5  */
   6 
   7 #include <linux/config.h>
   8 #include <linux/signal.h>
   9 #include <linux/sched.h>
  10 #include <linux/head.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/string.h>
  14 #include <linux/types.h>
  15 #include <linux/ptrace.h>
  16 #include <linux/mman.h>
  17 #include <linux/mm.h>
  18 #include <linux/swap.h>
  19 
  20 #include <asm/system.h>
  21 #include <asm/segment.h>
  22 #include <asm/pgtable.h>
  23 #include <asm/hwrpb.h>
  24 
  25 extern void die_if_kernel(char *,struct pt_regs *,long);
  26 extern void show_net_buffers(void);
  27 
  28 /*
  29  * BAD_PAGE is the page that is used for page faults when linux
  30  * is out-of-memory. Older versions of linux just did a
  31  * do_exit(), but using this instead means there is less risk
  32  * for a process dying in kernel mode, possibly leaving a inode
  33  * unused etc..
  34  *
  35  * BAD_PAGETABLE is the accompanying page-table: it is initialized
  36  * to point to BAD_PAGE entries.
  37  *
  38  * ZERO_PAGE is a special page that is used for zero-initialized
  39  * data and COW.
  40  */
  41 pmd_t * __bad_pagetable(void)
     /*  */
  42 {
  43         memset((void *) EMPTY_PGT, 0, PAGE_SIZE);
  44         return (pmd_t *) EMPTY_PGT;
  45 }
  46 
  47 pte_t __bad_page(void)
     /*  */
  48 {
  49         memset((void *) EMPTY_PGE, 0, PAGE_SIZE);
  50         return pte_mkdirty(mk_pte((unsigned long) EMPTY_PGE, PAGE_SHARED));
  51 }
  52 
  53 void show_mem(void)
     /*  */
  54 {
  55         int i,free = 0,total = 0,reserved = 0;
  56         int shared = 0;
  57 
  58         printk("\nMem-info:\n");
  59         show_free_areas();
  60         printk("Free swap:       %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
  61         i = MAP_NR(high_memory);
  62         while (i-- > 0) {
  63                 total++;
  64                 if (mem_map[i].reserved)
  65                         reserved++;
  66                 else if (!mem_map[i].count)
  67                         free++;
  68                 else
  69                         shared += mem_map[i].count-1;
  70         }
  71         printk("%d pages of RAM\n",total);
  72         printk("%d free pages\n",free);
  73         printk("%d reserved pages\n",reserved);
  74         printk("%d pages shared\n",shared);
  75         show_buffers();
  76 #ifdef CONFIG_NET
  77         show_net_buffers();
  78 #endif
  79 }
  80 
  81 extern unsigned long free_area_init(unsigned long, unsigned long);
  82 
  83 static void load_PCB(struct thread_struct * pcb)
     /*  */
  84 {
  85         __asm__ __volatile__(
  86                 "stq $30,0(%0)\n\t"
  87                 "bis %0,%0,$16\n\t"
  88                 "call_pal %1"
  89                 : /* no outputs */
  90                 : "r" (pcb), "i" (PAL_swpctx)
  91                 : "$0", "$1", "$16", "$22", "$23", "$24", "$25");
  92 }
  93 
  94 /*
  95  * paging_init() sets up the page tables: in the alpha version this actually
  96  * unmaps the bootup page table (as we're now in KSEG, so we don't need it).
  97  */
  98 unsigned long paging_init(unsigned long start_mem, unsigned long end_mem)
     /*  */
  99 {
 100         int i;
 101         unsigned long newptbr;
 102         struct memclust_struct * cluster;
 103         struct memdesc_struct * memdesc;
 104 
 105         /* initialize mem_map[] */
 106         start_mem = free_area_init(start_mem, end_mem);
 107 
 108         /* find free clusters, update mem_map[] accordingly */
 109         memdesc = (struct memdesc_struct *) (INIT_HWRPB->mddt_offset + (unsigned long) INIT_HWRPB);
 110         cluster = memdesc->cluster;
 111         for (i = memdesc->numclusters ; i > 0; i--, cluster++) {
 112                 unsigned long pfn, nr;
 113                 if (cluster->usage & 1)
 114                         continue;
 115                 pfn = cluster->start_pfn;
 116                 nr = cluster->numpages;
 117 
 118                 /* non-volatile memory. We might want to mark this for later */
 119                 if (cluster->usage & 2)
 120                         continue;
 121 
 122                 while (nr--)
 123                         mem_map[pfn++].reserved = 0;
 124         }
 125 
 126         /* unmap the console stuff: we don't need it, and we don't want it */
 127         /* Also set up the real kernel PCB while we're at it.. */
 128         memset((void *) ZERO_PAGE, 0, PAGE_SIZE);
 129         memset(swapper_pg_dir, 0, PAGE_SIZE);
 130         newptbr = ((unsigned long) swapper_pg_dir - PAGE_OFFSET) >> PAGE_SHIFT;
 131         pgd_val(swapper_pg_dir[1023]) = (newptbr << 32) | pgprot_val(PAGE_KERNEL);
 132         init_task.tss.ptbr = newptbr;
 133         init_task.tss.flags = 1;
 134         init_task.kernel_stack_page = INIT_STACK;
 135         load_PCB(&init_task.tss);
 136 
 137         invalidate_all();
 138         return start_mem;
 139 }
 140 
 141 void mem_init(unsigned long start_mem, unsigned long end_mem)
     /*  */
 142 {
 143         unsigned long tmp;
 144 
 145         end_mem &= PAGE_MASK;
 146         high_memory = end_mem;
 147         start_mem = PAGE_ALIGN(start_mem);
 148 
 149         /*
 150          * Mark the pages used by the kernel as reserved..
 151          */
 152         tmp = KERNEL_START;
 153         while (tmp < start_mem) {
 154                 mem_map[MAP_NR(tmp)].reserved = 1;
 155                 tmp += PAGE_SIZE;
 156         }
 157 
 158         for (tmp = PAGE_OFFSET ; tmp < high_memory ; tmp += PAGE_SIZE) {
 159                 if (mem_map[MAP_NR(tmp)].reserved)
 160                         continue;
 161                 mem_map[MAP_NR(tmp)].count = 1;
 162                 free_page(tmp);
 163         }
 164         tmp = nr_free_pages << PAGE_SHIFT;
 165         printk("Memory: %luk available\n", tmp >> 10);
 166         return;
 167 }
 168 
 169 void si_meminfo(struct sysinfo *val)
     /*  */
 170 {
 171         int i;
 172 
 173         i = MAP_NR(high_memory);
 174         val->totalram = 0;
 175         val->sharedram = 0;
 176         val->freeram = nr_free_pages << PAGE_SHIFT;
 177         val->bufferram = buffermem;
 178         while (i-- > 0)  {
 179                 if (mem_map[i].reserved)
 180                         continue;
 181                 val->totalram++;
 182                 if (!mem_map[i].count)
 183                         continue;
 184                 val->sharedram += mem_map[i].count-1;
 185         }
 186         val->totalram <<= PAGE_SHIFT;
 187         val->sharedram <<= PAGE_SHIFT;
 188         return;
 189 }
/* */
root/arch/alpha/mm/init.c

DEFINITIONS
