linux-kernel-test/arch/powerpc/kernel/vdso32/datapage.S
Benjamin Herrenschmidt 0c37ec2aa8 [PATCH] powerpc: vdso fixes (take #2)
This fixes various errors in the new functions added in the vDSO's,
I've now verified all functions on both 32 and 64 bits vDSOs. It also
fix a sign extension bug getting the initial time of day at boot that
could cause the monotonic clock value to be completely on bogus for
64 bits applications (with either the vDSO or the syscall) on
powermacs.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-14 16:35:58 +11:00

86 lines
2.0 KiB
ArmAsm

/*
* 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 <linux/config.h>
#include <asm/processor.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/vdso.h>
.text
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 20,31,1f
.global __kernel_datapage_offset;
__kernel_datapage_offset:
.long 0
1:
mflr r3
mtlr r0
lwz r0,0(r3)
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)
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
blr
.cfi_endproc
V_FUNCTION_END(__kernel_get_tbfreq)