src/arch/x86/include/mode_switch.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <stdint.h>
   4
   5 #if ENV_X86_64
   6 /*
   7  * Assembly code that drops into protected mode and calls the function
   8  * specified as first argument, which must have been compiled for x86_32.
   9  * After the function returns it enters long mode again.
  10  * The function pointer destination must be below 4GiB in physical memory.
  11  *
  12  * The called function has 0-3 arguments and returns an int.
  13  */
  14 int protected_mode_call_wrapper(uint32_t func_ptr,
  15                                 uint32_t opt_arg1,
  16                                 uint32_t opt_arg2,
  17                                 uint32_t opt_arg3);
  18
  19 /*
  20  * Drops into protected mode and calls the function, which must have been compiled for x86_32.
  21  * After the function returns it enters long mode again.
  22  * The function pointer destination must be below 4GiB in physical memory.
  23  *
  24  * The called function doesn't have arguments and returns an int.
  25  */
  26 static inline int protected_mode_call(void *func)
  27 {
  28         return protected_mode_call_wrapper((uintptr_t)func, 0, 0, 0);
  29 }
  30
  31 /*
  32  * Drops into protected mode and calls the function, which must have been compiled for x86_32.
  33  * After the function returns it enters long mode again.
  34  * The function pointer destination must be below 4GiB in physical memory.
  35  * Only the lower 32bits of the argument are passed to the called function.
  36  *
  37  * The called function have one argument and returns an int.
  38  */
  39 static inline int protected_mode_call_1arg(void *func, uint32_t arg1)
  40 {
  41         return protected_mode_call_wrapper((uintptr_t)func, arg1, 0, 0);
  42 }
  43
  44 /*
  45  * Drops into protected mode and calls the function, which must have been compiled for x86_32.
  46  * After the function returns it enters long mode again.
  47  * The function pointer destination must be below 4GiB in physical memory.
  48  * Only the lower 32bits of the argument are passed to the called function.
  49  *
  50  * The called function has two arguments and returns an int.
  51  */
  52 static inline int protected_mode_call_2arg(void *func, uint32_t arg1, uint32_t arg2)
  53 {
  54         return protected_mode_call_wrapper((uintptr_t)func, arg1, arg2, 0);
  55 }
  56
  57 /*
  58  * Drops into protected mode and calls the function, which must have been compiled for x86_32.
  59  * After the function returns it enters long mode again.
  60  * The function pointer destination must be below 4GiB in physical memory.
  61  * Only the lower 32bits of the argument are passed to the called function.
  62  *
  63  * The called function has two arguments and returns an int.
  64  */
  65 static inline int protected_mode_call_3arg(void *func, uint32_t arg1, uint32_t arg2,
  66                                            uint32_t arg3)
  67 {
  68         return protected_mode_call_wrapper((uintptr_t)func, arg1, arg2, arg3);
  69 }
  70 #else
  71 static inline int protected_mode_call(void *func)
  72 {
  73         int (*doit)(void) = func;
  74
  75         return doit();
  76 }
  77
  78 static inline int protected_mode_call_1arg(void *func, uint32_t arg1)
  79 {
  80         int (*doit)(uint32_t arg1) = func;
  81
  82         return doit(arg1);
  83 }
  84
  85 static inline int protected_mode_call_2arg(void *func, uint32_t arg1, uint32_t arg2)
  86 {
  87         int (*doit)(uint32_t arg1, uint32_t arg2) = func;
  88
  89         return doit(arg1, arg2);
  90 }
  91
  92 static inline int protected_mode_call_3arg(void *func, uint32_t arg1, uint32_t arg2,
  93                                            uint32_t arg3)
  94 {
  95         int (*doit)(uint32_t arg1, uint32_t arg2, uint32_t arg3) = func;
  96
  97         return doit(arg1, arg2, arg3);
  98 }
  99 #endif