xref: /linux/arch/x86/include/asm/apm.h (revision d99ff463ecf651437e9e4abe68f331dfb6b5bd9d)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  Machine specific APM BIOS functions for generic.
4  *  Split out from apm.c by Osamu Tomita <tomita@cinet.co.jp>
5  */
6 
7 #ifndef _ASM_X86_MACH_DEFAULT_APM_H
8 #define _ASM_X86_MACH_DEFAULT_APM_H
9 
10 #ifdef APM_ZERO_SEGS
11 #	define APM_DO_ZERO_SEGS \
12 		"pushl %%ds\n\t" \
13 		"pushl %%es\n\t" \
14 		"xorl %%edx, %%edx\n\t" \
15 		"mov %%dx, %%ds\n\t" \
16 		"mov %%dx, %%es\n\t" \
17 		"mov %%dx, %%fs\n\t" \
18 		"mov %%dx, %%gs\n\t"
19 #	define APM_DO_POP_SEGS \
20 		"popl %%es\n\t" \
21 		"popl %%ds\n\t"
22 #else
23 #	define APM_DO_ZERO_SEGS
24 #	define APM_DO_POP_SEGS
25 #endif
26 
27 static inline void apm_bios_call_asm(u32 func, u32 ebx_in, u32 ecx_in,
28 					u32 *eax, u32 *ebx, u32 *ecx,
29 					u32 *edx, u32 *esi)
30 {
31 	/*
32 	 * N.B. We do NOT need a cld after the BIOS call
33 	 * because we always save and restore the flags.
34 	 */
35 	__asm__ __volatile__(APM_DO_ZERO_SEGS
36 		"pushl %%edi\n\t"
37 		"pushl %%ebp\n\t"
38 		"lcall *%%cs:apm_bios_entry\n\t"
39 		"setc %%al\n\t"
40 		"popl %%ebp\n\t"
41 		"popl %%edi\n\t"
42 		APM_DO_POP_SEGS
43 		: "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx),
44 		  "=S" (*esi)
45 		: "a" (func), "b" (ebx_in), "c" (ecx_in)
46 		: "memory", "cc");
47 }
48 
49 static inline bool apm_bios_call_simple_asm(u32 func, u32 ebx_in,
50 					    u32 ecx_in, u32 *eax)
51 {
52 	int	cx, dx, si;
53 	bool	error;
54 
55 	/*
56 	 * N.B. We do NOT need a cld after the BIOS call
57 	 * because we always save and restore the flags.
58 	 */
59 	__asm__ __volatile__(APM_DO_ZERO_SEGS
60 		"pushl %%edi\n\t"
61 		"pushl %%ebp\n\t"
62 		"lcall *%%cs:apm_bios_entry\n\t"
63 		"setc %%bl\n\t"
64 		"popl %%ebp\n\t"
65 		"popl %%edi\n\t"
66 		APM_DO_POP_SEGS
67 		: "=a" (*eax), "=b" (error), "=c" (cx), "=d" (dx),
68 		  "=S" (si)
69 		: "a" (func), "b" (ebx_in), "c" (ecx_in)
70 		: "memory", "cc");
71 	return error;
72 }
73 
74 #endif /* _ASM_X86_MACH_DEFAULT_APM_H */
75