arch/s390/mm/mem_detect.c

   1 /*
   2  * Copyright IBM Corp. 2008, 2009
   3  *
   4  * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/module.h>
   9 #include <linux/memblock.h>
  10 #include <linux/init.h>
  11 #include <linux/debugfs.h>
  12 #include <linux/seq_file.h>
  13 #include <asm/ipl.h>
  14 #include <asm/sclp.h>
  15 #include <asm/setup.h>
  16
  17 #define CHUNK_READ_WRITE 0
  18 #define CHUNK_READ_ONLY  1
  19
  20 static inline void memblock_physmem_add(phys_addr_t start, phys_addr_t size)
  21 {
  22         memblock_add_range(&memblock.memory, start, size, 0, 0);
  23         memblock_add_range(&memblock.physmem, start, size, 0, 0);
  24 }
  25
  26 void __init detect_memory_memblock(void)
  27 {
  28         unsigned long memsize, rnmax, rzm, addr, size;
  29         int type;
  30
  31         rzm = sclp.rzm;
  32         rnmax = sclp.rnmax;
  33         memsize = rzm * rnmax;
  34         if (!rzm)
  35                 rzm = 1UL << 17;
  36         max_physmem_end = memsize;
  37         addr = 0;
  38         /* keep memblock lists close to the kernel */
  39         memblock_set_bottom_up(true);
  40         do {
  41                 size = 0;
  42                 type = tprot(addr);
  43                 do {
  44                         size += rzm;
  45                         if (max_physmem_end && addr + size >= max_physmem_end)
  46                                 break;
  47                 } while (type == tprot(addr + size));
  48                 if (type == CHUNK_READ_WRITE || type == CHUNK_READ_ONLY) {
  49                         if (max_physmem_end && (addr + size > max_physmem_end))
  50                                 size = max_physmem_end - addr;
  51                         memblock_physmem_add(addr, size);
  52                 }
  53                 addr += size;
  54         } while (addr < max_physmem_end);
  55         memblock_set_bottom_up(false);
  56         if (!max_physmem_end)
  57                 max_physmem_end = memblock_end_of_DRAM();
  58 }