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/memblock.h>
   9 #include <linux/init.h>
  10 #include <linux/debugfs.h>
  11 #include <linux/seq_file.h>
  12 #include <asm/ipl.h>
  13 #include <asm/sclp.h>
  14 #include <asm/setup.h>
  15
  16 #define CHUNK_READ_WRITE 0
  17 #define CHUNK_READ_ONLY  1
  18
  19 static inline void memblock_physmem_add(phys_addr_t start, phys_addr_t size)
  20 {
  21         memblock_dbg("memblock_physmem_add: [%#016llx-%#016llx]\n",
  22                      start, start + size - 1);
  23         memblock_add_range(&memblock.memory, start, size, 0, 0);
  24         memblock_add_range(&memblock.physmem, start, size, 0, 0);
  25 }
  26
  27 void __init detect_memory_memblock(void)
  28 {
  29         unsigned long memsize, rnmax, rzm, addr, size;
  30         int type;
  31
  32         rzm = sclp.rzm;
  33         rnmax = sclp.rnmax;
  34         memsize = rzm * rnmax;
  35         if (!rzm)
  36                 rzm = 1UL << 17;
  37         max_physmem_end = memsize;
  38         addr = 0;
  39         /* keep memblock lists close to the kernel */
  40         memblock_set_bottom_up(true);
  41         do {
  42                 size = 0;
  43                 /* assume lowcore is writable */
  44                 type = addr ? tprot(addr) : CHUNK_READ_WRITE;
  45                 do {
  46                         size += rzm;
  47                         if (max_physmem_end && addr + size >= max_physmem_end)
  48                                 break;
  49                 } while (type == tprot(addr + size));
  50                 if (type == CHUNK_READ_WRITE || type == CHUNK_READ_ONLY) {
  51                         if (max_physmem_end && (addr + size > max_physmem_end))
  52                                 size = max_physmem_end - addr;
  53                         memblock_physmem_add(addr, size);
  54                 }
  55                 addr += size;
  56         } while (addr < max_physmem_end);
  57         memblock_set_bottom_up(false);
  58         if (!max_physmem_end)
  59                 max_physmem_end = memblock_end_of_DRAM();
  60         memblock_dump_all();
  61 }