diff options
Diffstat (limited to 'arch/powerpc/kernel/vdso64/datapage.S')
| -rw-r--r-- | arch/powerpc/kernel/vdso64/datapage.S | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/vdso64/datapage.S b/arch/powerpc/kernel/vdso64/datapage.S new file mode 100644 index 000000000..067247d3e --- /dev/null +++ b/arch/powerpc/kernel/vdso64/datapage.S @@ -0,0 +1,62 @@ +/* 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> +#include <asm/vdso_datapage.h> + + .text +.global __kernel_datapage_offset; +__kernel_datapage_offset: + .long 0 + +/* + * 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 + get_datapage r3, r0 + 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 + get_datapage r3, r0 + ld r3,CFG_TB_TICKS_PER_SEC(r3) + mtlr r12 + crclr cr0*4+so + blr + .cfi_endproc +V_FUNCTION_END(__kernel_get_tbfreq) |