vdso_datapage.h

Go to the documentation of this file.

#ifndef _VDSO_DATAPAGE_H
#define _VDSO_DATAPAGE_H
#ifdef __KERNEL__

/*
 * Copyright (C) 2002 Peter Bergner <bergner@vnet.ibm.com>, IBM
 * Copyright (C) 2005 Benjamin Herrenschmidy <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.
 */


/*
 * Note about this structure:
 *
 * This structure was historically called systemcfg and exposed to
 * userland via /proc/ppc64/systemcfg. Unfortunately, this became an
 * ABI issue as some proprietary software started relying on being able
 * to mmap() it, thus we have to keep the base layout at least for a
 * few kernel versions.
 *
 * However, since ppc32 doesn't suffer from this backward handicap,
 * a simpler version of the data structure is used there with only the
 * fields actually used by the vDSO.
 *
 */

/*
 * If the major version changes we are incompatible.
 * Minor version changes are a hint.
 */
#define SYSTEMCFG_MAJOR 1
#define SYSTEMCFG_MINOR 1

#ifndef __ASSEMBLY__

#include <linux/unistd.h>
#include <linux/time.h>

#define SYSCALL_MAP_SIZE      ((__NR_syscalls + 31) / 32)

/*
 * So here is the ppc64 backward compatible version
 */

#ifdef CONFIG_PPC64

struct vdso_data {
    __u8  eye_catcher[16];      /* Eyecatcher: SYSTEMCFG:PPC64  0x00 */
    struct {            /* Systemcfg version numbers         */
        __u32 major;        /* Major number         0x10 */
        __u32 minor;        /* Minor number         0x14 */
    } version;

    /* Note about the platform flags: it now only contains the lpar
     * bit. The actual platform number is dead and buried
     */
    __u32 platform;         /* Platform flags       0x18 */
    __u32 processor;        /* Processor type       0x1C */
    __u64 processorCount;       /* # of physical processors 0x20 */
    __u64 physicalMemorySize;   /* Size of real memory(B)   0x28 */
    __u64 tb_orig_stamp;        /* Timebase at boot     0x30 */
    __u64 tb_ticks_per_sec;     /* Timebase tics / sec      0x38 */
    __u64 tb_to_xs;         /* Inverse of TB to 2^20    0x40 */
    __u64 stamp_xsec;       /*              0x48 */
    __u64 tb_update_count;      /* Timebase atomicity ctr   0x50 */
    __u32 tz_minuteswest;       /* Minutes west of Greenwich    0x58 */
    __u32 tz_dsttime;       /* Type of dst correction   0x5C */
    __u32 dcache_size;      /* L1 d-cache size      0x60 */
    __u32 dcache_line_size;     /* L1 d-cache line size     0x64 */
    __u32 icache_size;      /* L1 i-cache size      0x68 */
    __u32 icache_line_size;     /* L1 i-cache line size     0x6C */

    /* those additional ones don't have to be located anywhere
     * special as they were not part of the original systemcfg
     */
    __u32 dcache_block_size;        /* L1 d-cache block size     */
    __u32 icache_block_size;        /* L1 i-cache block size     */
    __u32 dcache_log_block_size;        /* L1 d-cache log block size */
    __u32 icache_log_block_size;        /* L1 i-cache log block size */
    __s32 wtom_clock_sec;           /* Wall to monotonic clock */
    __s32 wtom_clock_nsec;
    struct timespec stamp_xtime;    /* xtime as at tb_orig_stamp */
    __u32 stamp_sec_fraction;   /* fractional seconds of stamp_xtime */
    __u32 syscall_map_64[SYSCALL_MAP_SIZE]; /* map of syscalls  */
    __u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */
};

#else /* CONFIG_PPC64 */

/*
 * And here is the simpler 32 bits version
 */
struct vdso_data {
    __u64 tb_orig_stamp;        /* Timebase at boot     0x30 */
    __u64 tb_ticks_per_sec;     /* Timebase tics / sec      0x38 */
    __u64 tb_to_xs;         /* Inverse of TB to 2^20    0x40 */
    __u64 stamp_xsec;       /*              0x48 */
    __u32 tb_update_count;      /* Timebase atomicity ctr   0x50 */
    __u32 tz_minuteswest;       /* Minutes west of Greenwich    0x58 */
    __u32 tz_dsttime;       /* Type of dst correction   0x5C */
    __s32 wtom_clock_sec;           /* Wall to monotonic clock */
    __s32 wtom_clock_nsec;
    struct timespec stamp_xtime;    /* xtime as at tb_orig_stamp */
    __u32 stamp_sec_fraction;   /* fractional seconds of stamp_xtime */
    __u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */
    __u32 dcache_block_size;    /* L1 d-cache block size     */
    __u32 icache_block_size;    /* L1 i-cache block size     */
    __u32 dcache_log_block_size;    /* L1 d-cache log block size */
    __u32 icache_log_block_size;    /* L1 i-cache log block size */
};

#endif /* CONFIG_PPC64 */

extern struct vdso_data *vdso_data;

#endif /* __ASSEMBLY__ */

#endif /* __KERNEL__ */
#endif /* _SYSTEMCFG_H */