target/linux/ramips/patches-3.8/0121-MIPS-add-detect_memory_region.patch

   1 From 9041c96ab5bd29d85ca95cffa44c755f68ae6bb1 Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Sat, 13 Apr 2013 13:15:47 +0200
   4 Subject: [PATCH 121/137] MIPS: add detect_memory_region()
   5
   6 Add a generic way of detecting the available RAM. This function is based on the
   7 implementation already used by ath79.
   8
   9 Signed-off-by: John Crispin <blogic@openwrt.org>
  10 Patchwork: http://patchwork.linux-mips.org/patch/5178/
  11 ---
  12  arch/mips/include/asm/bootinfo.h |    1 +
  13  arch/mips/kernel/setup.c         |   20 ++++++++++++++++++++
  14  2 files changed, 21 insertions(+)
  15
  16 --- a/arch/mips/include/asm/bootinfo.h
  17 +++ b/arch/mips/include/asm/bootinfo.h
  18 @@ -104,6 +104,7 @@ struct boot_mem_map {
  19  extern struct boot_mem_map boot_mem_map;
  20
  21  extern void add_memory_region(phys_t start, phys_t size, long type);
  22 +extern void detect_memory_region(phys_t start, phys_t sz_min,  phys_t sz_max);
  23
  24  extern void prom_init(void);
  25  extern void prom_free_prom_memory(void);
  26 --- a/arch/mips/kernel/setup.c
  27 +++ b/arch/mips/kernel/setup.c
  28 @@ -23,6 +23,7 @@
  29  #include <linux/pfn.h>
  30  #include <linux/debugfs.h>
  31  #include <linux/kexec.h>
  32 +#include <linux/sizes.h>
  33
  34  #include <asm/addrspace.h>
  35  #include <asm/bootinfo.h>
  36 @@ -122,6 +123,25 @@ void __init add_memory_region(phys_t sta
  37         boot_mem_map.nr_map++;
  38  }
  39
  40 +void __init detect_memory_region(phys_t start, phys_t sz_min, phys_t sz_max)
  41 +{
  42 +       phys_t size;
  43 +
  44 +       for (size = sz_min; size < sz_max; size <<= 1) {
  45 +               if (!memcmp(detect_memory_region,
  46 +                               detect_memory_region + size, 1024))
  47 +                       break;
  48 +       }
  49 +
  50 +       pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n",
  51 +               ((unsigned long long) size) / SZ_1M,
  52 +               (unsigned long long) start,
  53 +               ((unsigned long long) sz_min) / SZ_1M,
  54 +               ((unsigned long long) sz_max) / SZ_1M);
  55 +
  56 +       add_memory_region(start, size, BOOT_MEM_RAM);
  57 +}
  58 +
  59  static void __init print_memory_map(void)
  60  {
  61         int i;