kernel/fiasco/src/kern/arm/kern_lib_page.cpp

   1 INTERFACE [arm]:
   2
   3 class Kern_lib_page
   4 {
   5 public:
   6   static void init();
   7 };
   8
   9
  10 //---------------------------------------------------------------------------
  11 IMPLEMENTATION [arm]:
  12
  13 #include <panic.h>
  14
  15 #include "kmem_space.h"
  16 #include "pagetable.h"
  17 #include "ram_quota.h"
  18
  19 IMPLEMENT
  20 void Kern_lib_page::init()
  21 {
  22   extern char kern_lib_start;
  23
  24   Pte pte = Kmem_space::kdir()->walk((void*)Kmem_space::Kern_lib_base,
  25       Config::PAGE_SIZE, true, Ram_quota::root);
  26
  27   if (pte.lvl() == 0) // allocation of second level faild
  28     {
  29       panic("FATAL: Error mapping cpu page to %p\n",
  30             (void*)Kmem_space::Kern_lib_base);
  31     }
  32
  33   pte.set((Address)&kern_lib_start - Mem_layout::Map_base
  34       + Mem_layout::Sdram_phys_base,
  35       Config::PAGE_SIZE, Mem_page_attr(Page::USER_RO | Page::CACHEABLE), true);
  36
  37 }
  38
  39 //---------------------------------------------------------------------------
  40 IMPLEMENTATION [arm && !armv6plus]:
  41
  42 asm (
  43     ".p2align(12)                        \n"
  44     "kern_lib_start:                     \n"
  45
  46     // atomic add
  47     // r0: memory reference
  48     // r1: delta value
  49     "  ldr r2, [r0]                      \n"
  50     "  add r2, r2, r1                    \n"
  51     "  nop                               \n"
  52     "  str r2, [r0]                      \n"
  53     // forward point
  54     "  mov r0, r2                        \n"
  55     "  mov pc, lr                        \n"
  56     // return: always succeeds, new value
  57
  58     // compare exchange
  59     // r0: memory reference
  60     // r1: cmp value
  61     // r2: new value
  62     ".p2align(8)                         \n"
  63     "  ldr r3, [r0]                      \n"
  64     "  cmp r3, r1                        \n"
  65     "  nop                               \n"
  66     "  streq r2, [r0]                    \n"
  67     // forward point
  68     "  moveq r0, #1                      \n"
  69     "  movne r0, #0                      \n"
  70     "  mov pc, lr                        \n"
  71     // return result: 1 success, 0 failure
  72
  73     // exchange
  74     //  in-r0: memory reference
  75     //  in-r1: new value
  76     // out-r0: old value
  77     ".p2align(8)                         \n"
  78     "  ldr r2, [r0]                      \n"
  79     "  nop                               \n"
  80     "  nop                               \n"
  81     "  str r1, [r0]                      \n"
  82     // forward point
  83     "  mov r0, r2                        \n"
  84     "  mov pc, lr                        \n"
  85     // return: always succeeds, old value
  86     );
  87
  88 //---------------------------------------------------------------------------
  89 IMPLEMENTATION [arm && armv6plus]:
  90
  91 asm (
  92     ".p2align(12)                        \n"
  93     "kern_lib_start:                     \n"
  94
  95     // no restart through kernel entry code
  96
  97     // atomic add
  98     // r0: memory reference
  99     // r1: delta value
 100     // r2: temp register
 101     // r3: temp register
 102     " 1:                                 \n"
 103     " ldrex r2, [r0]                     \n"
 104     " add   r2, r2, r1                   \n"
 105     " strex r3, r2, [r0]                 \n"
 106     " teq r3, #0                         \n"
 107     " bne 1b                             \n"
 108     " mov r0, r2                         \n"
 109     " mov pc, lr                         \n"
 110     // return: always succeeds, new value
 111
 112
 113     // compare exchange
 114     // r0: memory reference
 115     // r1: cmp value
 116     // r2: new value
 117     // r3: tmp reg
 118     ".p2align(8)                         \n"
 119     "  ldrex r3, [r0]                    \n"
 120     "  cmp r3, r1                        \n"
 121     "  strexeq r3, r2, [r0]              \n"
 122     "  teqeq r3, #0                      \n"
 123     "  moveq r0, #1                      \n"
 124     "  movne r0, #0                      \n"
 125     "  mov pc, lr                        \n"
 126     // return result: 1 success, 0 failure
 127
 128
 129     // exchange
 130     //  in-r0: memory reference
 131     //  in-r1: new value
 132     // out-r0: old value
 133     ".p2align(8)                         \n"
 134     "  1:                                \n"
 135     "  ldrex r2, [r0]                    \n"
 136     "  strex r3, r1, [r0]                \n"
 137     "  cmp r3, #0                        \n"
 138     "  bne 1b                            \n"
 139     "  mov r0, r2                        \n"
 140     "  mov pc, lr                        \n"
 141     // return: always succeeds, old value
 142     );