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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Machine specific APM BIOS functions for generic.
* Split out from apm.c by Osamu Tomita <tomita@cinet.co.jp>
*/
#ifndef _ASM_X86_MACH_DEFAULT_APM_H
#define _ASM_X86_MACH_DEFAULT_APM_H
#include <asm/nospec-branch.h>
#ifdef APM_ZERO_SEGS
# define APM_DO_ZERO_SEGS \
"pushl %%ds\n\t" \
"pushl %%es\n\t" \
"xorl %%edx, %%edx\n\t" \
"mov %%dx, %%ds\n\t" \
"mov %%dx, %%es\n\t" \
"mov %%dx, %%fs\n\t" \
"mov %%dx, %%gs\n\t"
# define APM_DO_POP_SEGS \
"popl %%es\n\t" \
"popl %%ds\n\t"
#else
# define APM_DO_ZERO_SEGS
# define APM_DO_POP_SEGS
#endif
static inline void apm_bios_call_asm(u32 func, u32 ebx_in, u32 ecx_in,
u32 *eax, u32 *ebx, u32 *ecx,
u32 *edx, u32 *esi)
{
/*
* N.B. We do NOT need a cld after the BIOS call
* because we always save and restore the flags.
*/
firmware_restrict_branch_speculation_start();
__asm__ __volatile__(APM_DO_ZERO_SEGS
"pushl %%edi\n\t"
"pushl %%ebp\n\t"
"lcall *%%cs:apm_bios_entry\n\t"
"setc %%al\n\t"
"popl %%ebp\n\t"
"popl %%edi\n\t"
APM_DO_POP_SEGS
: "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx),
"=S" (*esi)
: "a" (func), "b" (ebx_in), "c" (ecx_in)
: "memory", "cc");
firmware_restrict_branch_speculation_end();
}
static inline bool apm_bios_call_simple_asm(u32 func, u32 ebx_in,
u32 ecx_in, u32 *eax)
{
int cx, dx, si;
bool error;
/*
* N.B. We do NOT need a cld after the BIOS call
* because we always save and restore the flags.
*/
firmware_restrict_branch_speculation_start();
__asm__ __volatile__(APM_DO_ZERO_SEGS
"pushl %%edi\n\t"
"pushl %%ebp\n\t"
"lcall *%%cs:apm_bios_entry\n\t"
"setc %%bl\n\t"
"popl %%ebp\n\t"
"popl %%edi\n\t"
APM_DO_POP_SEGS
: "=a" (*eax), "=b" (error), "=c" (cx), "=d" (dx),
"=S" (si)
: "a" (func), "b" (ebx_in), "c" (ecx_in)
: "memory", "cc");
firmware_restrict_branch_speculation_end();
return error;
}
#endif /* _ASM_X86_MACH_DEFAULT_APM_H */
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