arch/sparc/prom/memory.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* memory.c: Prom routine for acquiring various bits of information
   3  *           about RAM on the machine, both virtual and physical.
   4  *
   5  * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
   6  * Copyright (C) 1997 Michael A. Griffith (grif@acm.org)
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/sort.h>
  11 #include <linux/init.h>
  12
  13 #include <asm/openprom.h>
  14 #include <asm/oplib.h>
  15 #include <asm/page.h>
  16
  17 static int __init prom_meminit_v0(void)
  18 {
  19         struct linux_mlist_v0 *p;
  20         int index;
  21
  22         index = 0;
  23         for (p = *(romvec->pv_v0mem.v0_available); p; p = p->theres_more) {
  24                 sp_banks[index].base_addr = (unsigned long) p->start_adr;
  25                 sp_banks[index].num_bytes = p->num_bytes;
  26                 index++;
  27         }
  28
  29         return index;
  30 }
  31
  32 static int __init prom_meminit_v2(void)
  33 {
  34         struct linux_prom_registers reg[64];
  35         phandle node;
  36         int size, num_ents, i;
  37
  38         node = prom_searchsiblings(prom_getchild(prom_root_node), "memory");
  39         size = prom_getproperty(node, "available", (char *) reg, sizeof(reg));
  40         num_ents = size / sizeof(struct linux_prom_registers);
  41
  42         for (i = 0; i < num_ents; i++) {
  43                 sp_banks[i].base_addr = reg[i].phys_addr;
  44                 sp_banks[i].num_bytes = reg[i].reg_size;
  45         }
  46
  47         return num_ents;
  48 }
  49
  50 static int sp_banks_cmp(const void *a, const void *b)
  51 {
  52         const struct sparc_phys_banks *x = a, *y = b;
  53
  54         if (x->base_addr > y->base_addr)
  55                 return 1;
  56         if (x->base_addr < y->base_addr)
  57                 return -1;
  58         return 0;
  59 }
  60
  61 /* Initialize the memory lists based upon the prom version. */
  62 void __init prom_meminit(void)
  63 {
  64         int i, num_ents = 0;
  65
  66         switch (prom_vers) {
  67         case PROM_V0:
  68                 num_ents = prom_meminit_v0();
  69                 break;
  70
  71         case PROM_V2:
  72         case PROM_V3:
  73                 num_ents = prom_meminit_v2();
  74                 break;
  75
  76         default:
  77                 break;
  78         }
  79         sort(sp_banks, num_ents, sizeof(struct sparc_phys_banks),
  80              sp_banks_cmp, NULL);
  81
  82         /* Sentinel.  */
  83         sp_banks[num_ents].base_addr = 0xdeadbeef;
  84         sp_banks[num_ents].num_bytes = 0;
  85
  86         for (i = 0; i < num_ents; i++)
  87                 sp_banks[i].num_bytes &= PAGE_MASK;
  88 }