| /* |
| * 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 V_LOCAL_FUNC(__get_datapage) |
| mtlr r12 |
| addi r3,r3,CFG_SYSCALL_MAP64 |
| cmpli 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) |
