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 */
protected_mode_call(void * func)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 */
protected_mode_call_1arg(void * func,uint32_t arg1)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 */
protected_mode_call_2arg(void * func,uint32_t arg1,uint32_t arg2)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 */
protected_mode_call_3arg(void * func,uint32_t arg1,uint32_t arg2,uint32_t arg3)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
protected_mode_call(void * func)71 static inline int protected_mode_call(void *func)
72 {
73 int (*doit)(void) = func;
74
75 return doit();
76 }
77
protected_mode_call_1arg(void * func,uint32_t arg1)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
protected_mode_call_2arg(void * func,uint32_t arg1,uint32_t arg2)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
protected_mode_call_3arg(void * func,uint32_t arg1,uint32_t arg2,uint32_t arg3)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
100