include/asm/apm.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  *  Machine specific APM BIOS functions for generic.
0004  *  Split out from apm.c by Osamu Tomita <tomita@cinet.co.jp>
0005  */
0006
0007 #ifndef _ASM_X86_MACH_DEFAULT_APM_H
0008 #define _ASM_X86_MACH_DEFAULT_APM_H
0009
0010 #ifdef APM_ZERO_SEGS
0011 #   define APM_DO_ZERO_SEGS \
0012         "pushl %%ds\n\t" \
0013         "pushl %%es\n\t" \
0014         "xorl %%edx, %%edx\n\t" \
0015         "mov %%dx, %%ds\n\t" \
0016         "mov %%dx, %%es\n\t" \
0017         "mov %%dx, %%fs\n\t" \
0018         "mov %%dx, %%gs\n\t"
0019 #   define APM_DO_POP_SEGS \
0020         "popl %%es\n\t" \
0021         "popl %%ds\n\t"
0022 #else
0023 #   define APM_DO_ZERO_SEGS
0024 #   define APM_DO_POP_SEGS
0025 #endif
0026
0027 static inline void apm_bios_call_asm(u32 func, u32 ebx_in, u32 ecx_in,
0028                     u32 *eax, u32 *ebx, u32 *ecx,
0029                     u32 *edx, u32 *esi)
0030 {
0031     /*
0032      * N.B. We do NOT need a cld after the BIOS call
0033      * because we always save and restore the flags.
0034      */
0035     __asm__ __volatile__(APM_DO_ZERO_SEGS
0036         "pushl %%edi\n\t"
0037         "pushl %%ebp\n\t"
0038         "lcall *%%cs:apm_bios_entry\n\t"
0039         "setc %%al\n\t"
0040         "popl %%ebp\n\t"
0041         "popl %%edi\n\t"
0042         APM_DO_POP_SEGS
0043         : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx),
0044           "=S" (*esi)
0045         : "a" (func), "b" (ebx_in), "c" (ecx_in)
0046         : "memory", "cc");
0047 }
0048
0049 static inline bool apm_bios_call_simple_asm(u32 func, u32 ebx_in,
0050                         u32 ecx_in, u32 *eax)
0051 {
0052     int cx, dx, si;
0053     bool    error;
0054
0055     /*
0056      * N.B. We do NOT need a cld after the BIOS call
0057      * because we always save and restore the flags.
0058      */
0059     __asm__ __volatile__(APM_DO_ZERO_SEGS
0060         "pushl %%edi\n\t"
0061         "pushl %%ebp\n\t"
0062         "lcall *%%cs:apm_bios_entry\n\t"
0063         "setc %%bl\n\t"
0064         "popl %%ebp\n\t"
0065         "popl %%edi\n\t"
0066         APM_DO_POP_SEGS
0067         : "=a" (*eax), "=b" (error), "=c" (cx), "=d" (dx),
0068           "=S" (si)
0069         : "a" (func), "b" (ebx_in), "c" (ecx_in)
0070         : "memory", "cc");
0071     return error;
0072 }
0073
0074 #endif /* _ASM_X86_MACH_DEFAULT_APM_H */