/* SPDX-License-Identifier: GPL-2.0 */
  #ifndef __VDSO_DATAPAGE_H
  #define __VDSO_DATAPAGE_H

  #ifndef __ASSEMBLY__

  #include <linux/compiler.h>
  #include <uapi/linux/time.h>
  #include <uapi/linux/types.h>
  #include <uapi/asm-generic/errno-base.h>
  
  #include <vdso/bits.h>
  #include <vdso/clocksource.h>
  #include <vdso/ktime.h>
  #include <vdso/limits.h>
  #include <vdso/math64.h>
  #include <vdso/processor.h>
  #include <vdso/time.h>
  #include <vdso/time32.h>
  #include <vdso/time64.h>

  #ifdef CONFIG_ARCH_HAS_VDSO_DATA
  #include <asm/vdso/data.h>
  #else
  struct arch_vdso_data {};
  #endif

  #define VDSO_BASES	(CLOCK_TAI + 1)
  #define VDSO_HRES	(BIT(CLOCK_REALTIME)		| \
  			 BIT(CLOCK_MONOTONIC)		| \
  			 BIT(CLOCK_BOOTTIME)		| \
  			 BIT(CLOCK_TAI))
  #define VDSO_COARSE	(BIT(CLOCK_REALTIME_COARSE)	| \
  			 BIT(CLOCK_MONOTONIC_COARSE))
  #define VDSO_RAW	(BIT(CLOCK_MONOTONIC_RAW))
  
  #define CS_HRES_COARSE	0
  #define CS_RAW		1
  #define CS_BASES	(CS_RAW + 1)
  
  /**
   * struct vdso_timestamp - basetime per clock_id
   * @sec:	seconds
   * @nsec:	nanoseconds
   *
   * There is one vdso_timestamp object in vvar for each vDSO-accelerated
   * clock_id. For high-resolution clocks, this encodes the time
   * corresponding to vdso_data.cycle_last. For coarse clocks this encodes
   * the actual time.
   *
   * To be noticed that for highres clocks nsec is left-shifted by
   * vdso_data.cs[x].shift.
   */
  struct vdso_timestamp {
  	u64	sec;
  	u64	nsec;
  };
  
  /**
   * struct vdso_data - vdso datapage representation
   * @seq:		timebase sequence counter
   * @clock_mode:		clock mode
   * @cycle_last:		timebase at clocksource init
   * @mask:		clocksource mask
   * @mult:		clocksource multiplier
   * @shift:		clocksource shift
   * @basetime[clock_id]:	basetime per clock_id

   * @offset[clock_id]:	time namespace offset per clock_id

   * @tz_minuteswest:	minutes west of Greenwich
   * @tz_dsttime:		type of DST correction
   * @hrtimer_res:	hrtimer resolution
   * @__unused:		unused

   * @arch_data:		architecture specific data (optional, defaults
   *			to an empty struct)

   *
   * vdso_data will be accessed by 64 bit and compat code at the same time
   * so we should be careful before modifying this structure.

   *
   * @basetime is used to store the base time for the system wide time getter
   * VVAR page.
   *
   * @offset is used by the special time namespace VVAR pages which are
   * installed instead of the real VVAR page. These namespace pages must set

   * @seq to 1 and @clock_mode to VDSO_CLOCKMODE_TIMENS to force the code into
   * the time namespace slow path. The namespace aware functions retrieve the

   * real system wide VVAR page, read host time and add the per clock offset.
   * For clocks which are not affected by time namespace adjustment the
   * offset must be zero.

   */
  struct vdso_data {
  	u32			seq;
  
  	s32			clock_mode;
  	u64			cycle_last;
  	u64			mask;
  	u32			mult;
  	u32			shift;

  	union {
  		struct vdso_timestamp	basetime[VDSO_BASES];
  		struct timens_offset	offset[VDSO_BASES];
  	};

  
  	s32			tz_minuteswest;
  	s32			tz_dsttime;
  	u32			hrtimer_res;
  	u32			__unused;

  
  	struct arch_vdso_data	arch_data;

  };
  
  /*
   * We use the hidden visibility to prevent the compiler from generating a GOT
   * relocation. Not only is going through a GOT useless (the entry couldn't and
   * must not be overridden by another library), it does not even work: the linker
   * cannot generate an absolute address to the data page.
   *
   * With the hidden visibility, the compiler simply generates a PC-relative
   * relocation, and this is what we need.
   */
  extern struct vdso_data _vdso_data[CS_BASES] __attribute__((visibility("hidden")));

  extern struct vdso_data _timens_data[CS_BASES] __attribute__((visibility("hidden")));

  /*
   * The generic vDSO implementation requires that gettimeofday.h
   * provides:
   * - __arch_get_vdso_data(): to get the vdso datapage.
   * - __arch_get_hw_counter(): to get the hw counter based on the
   *   clock_mode.
   * - gettimeofday_fallback(): fallback for gettimeofday.
   * - clock_gettime_fallback(): fallback for clock_gettime.
   * - clock_getres_fallback(): fallback for clock_getres.
   */
  #ifdef ENABLE_COMPAT_VDSO
  #include <asm/vdso/compat_gettimeofday.h>
  #else
  #include <asm/vdso/gettimeofday.h>
  #endif /* ENABLE_COMPAT_VDSO */

  #endif /* !__ASSEMBLY__ */

  #endif /* __VDSO_DATAPAGE_H */