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

source code of linux/arch/x86/include/asm/apm.h