/* * 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) 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)