/*
|
* Access to the shared data page by the vDSO & syscall map
|
*
|
* Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp.
|
*
|
* 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.
|
*/
|
|
#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 __get_datapage@local
|
mtlr r12
|
addi r3,r3,CFG_SYSCALL_MAP32
|
cmpli cr0,r4,0
|
beqlr
|
li r0,NR_syscalls
|
stw r0,0(r4)
|
crclr cr0*4+so
|
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
|
bl __get_datapage@local
|
lwz r4,(CFG_TB_TICKS_PER_SEC + 4)(r3)
|
lwz r3,CFG_TB_TICKS_PER_SEC(r3)
|
mtlr r12
|
crclr cr0*4+so
|
blr
|
.cfi_endproc
|
V_FUNCTION_END(__kernel_get_tbfreq)
|
