linux/linux-5.18.11/arch/powerpc/kernel/vdso/datapage.S

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2024-03-22 18:12:32 +00:00
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Access to the shared data page by the vDSO & syscall map
*
* Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp.
*/
#include <asm/processor.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/vdso.h>
#include <asm/vdso_datapage.h>
.text
/*
* void *__kernel_get_syscall_map(unsigned int *syscall_count) ;
*
* returns a pointer to the syscall map. the map is agnostic to the
* size of "long", unlike kernel bitops, it stores bits from top to
* bottom so that memory actually contains a linear bitmap
* check for syscall N by testing bit (0x80000000 >> (N & 0x1f)) of
* 32 bits int at N >> 5.
*/
V_FUNCTION_BEGIN(__kernel_get_syscall_map)
.cfi_startproc
mflr r12
.cfi_register lr,r12
mr. r4,r3
get_datapage r3
mtlr r12
#ifdef __powerpc64__
addi r3,r3,CFG_SYSCALL_MAP64
#else
addi r3,r3,CFG_SYSCALL_MAP32
#endif
crclr cr0*4+so
beqlr
li r0,NR_syscalls
stw r0,0(r4)
blr
.cfi_endproc
V_FUNCTION_END(__kernel_get_syscall_map)
/*
* void unsigned long long __kernel_get_tbfreq(void);
*
* returns the timebase frequency in HZ
*/
V_FUNCTION_BEGIN(__kernel_get_tbfreq)
.cfi_startproc
mflr r12
.cfi_register lr,r12
get_datapage r3
#ifndef __powerpc64__
lwz r4,(CFG_TB_TICKS_PER_SEC + 4)(r3)
#endif
PPC_LL r3,CFG_TB_TICKS_PER_SEC(r3)
mtlr r12
crclr cr0*4+so
blr
.cfi_endproc
V_FUNCTION_END(__kernel_get_tbfreq)