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
27static 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
49static 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