linux/arch/powerpc/kernel/vdso64/datapage.S
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

85 lines
1.8 KiB
ArmAsm

/* 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>
.text
.global __kernel_datapage_offset;
__kernel_datapage_offset:
.long 0
V_FUNCTION_BEGIN(__get_datapage)
.cfi_startproc
/* We don't want that exposed or overridable as we want other objects
* to be able to bl directly to here
*/
.protected __get_datapage
.hidden __get_datapage
mflr r0
.cfi_register lr,r0
bcl 20,31,data_page_branch
data_page_branch:
mflr r3
mtlr r0
addi r3, r3, __kernel_datapage_offset-data_page_branch
lwz r0,0(r3)
.cfi_restore lr
add r3,r0,r3
blr
.cfi_endproc
V_FUNCTION_END(__get_datapage)
/*
* 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
bl V_LOCAL_FUNC(__get_datapage)
mtlr r12
addi r3,r3,CFG_SYSCALL_MAP64
cmpldi cr0,r4,0
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 __kernel_get_tbfreq(void);
*
* returns the timebase frequency in HZ
*/
V_FUNCTION_BEGIN(__kernel_get_tbfreq)
.cfi_startproc
mflr r12
.cfi_register lr,r12
bl V_LOCAL_FUNC(__get_datapage)
ld r3,CFG_TB_TICKS_PER_SEC(r3)
mtlr r12
crclr cr0*4+so
blr
.cfi_endproc
V_FUNCTION_END(__kernel_get_tbfreq)