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_alloc.h"
  16 #include "kmem_space.h"
  17 #include "ram_quota.h"
  18 #include "paging.h"
  19
  20 IMPLEMENT_DEFAULT
  21 void Kern_lib_page::init()
  22 {
  23   extern char kern_lib_start;
  24   auto pte = Kmem_space::kdir()->walk(Virt_addr(Kmem_space::Kern_lib_base),
  25       Pdir::Depth, true,
  26       Kmem_alloc::q_allocator(Ram_quota::root));
  27
  28   if (pte.level == 0) // allocation of second level faild
  29     panic("FATAL: Error mapping kernel-lib page to %p\n",
  30           (void *)Kmem_space::Kern_lib_base);
  31
  32   pte.create_page(Phys_mem_addr((Address)&kern_lib_start - Mem_layout::Map_base
  33           + Mem_layout::Sdram_phys_base), Page::Attr(Page::Rights::URX(), Page::Type::Normal(), Page::Kern::Global()));
  34   pte.write_back_if(true, Mem_unit::Asid_kernel);
  35 }
  36
  37 //---------------------------------------------------------------------------
  38 IMPLEMENTATION [arm && hyp]:
  39
  40 IMPLEMENT_OVERRIDE inline void Kern_lib_page::init() {}
  41
  42 //---------------------------------------------------------------------------
  43 IMPLEMENTATION [arm && !armv6plus]:
  44
  45 asm (
  46     ".p2align(12)                        \n"
  47     "kern_lib_start:                     \n"
  48
  49     // atomic add
  50     // r0: memory reference
  51     // r1: delta value
  52     "  ldr r2, [r0]                      \n"
  53     "  add r2, r2, r1                    \n"
  54     "  nop                               \n"
  55     "  str r2, [r0]                      \n"
  56     // forward point
  57     "  mov r0, r2                        \n"
  58     "  mov pc, lr                        \n"
  59     // return: always succeeds, new value
  60
  61     // compare exchange
  62     // r0: memory reference
  63     // r1: cmp value
  64     // r2: new value
  65     // r3: tmp
  66     ".p2align(8)                         \n"
  67     "  ldr r3, [r0]                      \n"
  68     "  cmp r3, r1                        \n"
  69     "  nop                               \n"
  70     "  streq r2, [r0]                    \n"
  71     // forward point
  72     "  moveq r0, #1                      \n"
  73     "  movne r0, #0                      \n"
  74     "  mov pc, lr                        \n"
  75     // return result: 1 success, 0 failure
  76
  77     // exchange
  78     //  in-r0: memory reference
  79     //  in-r1: new value
  80     // out-r0: old value
  81     // tmp-r2
  82     ".p2align(8)                         \n"
  83     "  ldr r2, [r0]                      \n"
  84     "  nop                               \n"
  85     "  nop                               \n"
  86     "  str r1, [r0]                      \n"
  87     // forward point
  88     "  mov r0, r2                        \n"
  89     "  mov pc, lr                        \n"
  90     // return: always succeeds, old value
  91     );
  92
  93 //---------------------------------------------------------------------------
  94 IMPLEMENTATION [arm && armv6plus]:
  95
  96 asm (
  97     ".p2align(12)                        \n"
  98     ".global kern_lib_start              \n" // need this for mem_space.cpp
  99     "kern_lib_start:                     \n"
 100
 101     // no restart through kernel entry code
 102
 103     // atomic add
 104     // r0: memory reference
 105     // r1: delta value
 106     // r2: temp register
 107     // r3: temp register
 108     " 1:                                 \n"
 109     " ldrex r2, [r0]                     \n"
 110     " add   r2, r2, r1                   \n"
 111     " strex r3, r2, [r0]                 \n"
 112     " teq r3, #0                         \n"
 113     " bne 1b                             \n"
 114     " mov r0, r2                         \n"
 115     " mov pc, lr                         \n"
 116     // return: always succeeds, new value
 117
 118
 119     // compare exchange
 120     // r0: memory reference
 121     // r1: cmp value
 122     // r2: new value
 123     // r3: tmp reg
 124     ".p2align(8)                         \n"
 125     "  1: ldrex r3, [r0]                 \n"
 126     "  cmp r3, r1                        \n"
 127     "  movne r0, #0                      \n"
 128     "  movne pc, lr                      \n"
 129     "  strex r3, r2, [r0]                \n"
 130     "  teq r3, #0                        \n"
 131     "  bne 1b                            \n"
 132     "  mov r0, #1                        \n"
 133     "  mov pc, lr                        \n"
 134     // return result: 1 success, 0 failure
 135
 136
 137     // exchange
 138     //  in-r0: memory reference
 139     //  in-r1: new value
 140     // out-r0: old value
 141     ".p2align(8)                         \n"
 142     "  1:                                \n"
 143     "  ldrex r2, [r0]                    \n"
 144     "  strex r3, r1, [r0]                \n"
 145     "  cmp r3, #0                        \n"
 146     "  bne 1b                            \n"
 147     "  mov r0, r2                        \n"
 148     "  mov pc, lr                        \n"
 149     // return: always succeeds, old value
 150     );