diff options
Diffstat (limited to 'include/vdso')
| -rw-r--r-- | include/vdso/bits.h | 9 | ||||
| -rw-r--r-- | include/vdso/clocksource.h | 22 | ||||
| -rw-r--r-- | include/vdso/const.h | 10 | ||||
| -rw-r--r-- | include/vdso/datapage.h | 142 | ||||
| -rw-r--r-- | include/vdso/helpers.h | 56 | ||||
| -rw-r--r-- | include/vdso/jiffies.h | 11 | ||||
| -rw-r--r-- | include/vdso/ktime.h | 16 | ||||
| -rw-r--r-- | include/vdso/limits.h | 19 | ||||
| -rw-r--r-- | include/vdso/math64.h | 24 | ||||
| -rw-r--r-- | include/vdso/processor.h | 14 | ||||
| -rw-r--r-- | include/vdso/time.h | 12 | ||||
| -rw-r--r-- | include/vdso/time32.h | 17 | ||||
| -rw-r--r-- | include/vdso/time64.h | 15 | ||||
| -rw-r--r-- | include/vdso/vsyscall.h | 14 |
14 files changed, 381 insertions, 0 deletions
diff --git a/include/vdso/bits.h b/include/vdso/bits.h new file mode 100644 index 000000000..6d005a1f5 --- /dev/null +++ b/include/vdso/bits.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_BITS_H +#define __VDSO_BITS_H + +#include <vdso/const.h> + +#define BIT(nr) (UL(1) << (nr)) + +#endif /* __VDSO_BITS_H */ diff --git a/include/vdso/clocksource.h b/include/vdso/clocksource.h new file mode 100644 index 000000000..c682e7c60 --- /dev/null +++ b/include/vdso/clocksource.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_CLOCKSOURCE_H +#define __VDSO_CLOCKSOURCE_H + +#include <vdso/limits.h> + +#ifdef CONFIG_GENERIC_GETTIMEOFDAY +#include <asm/vdso/clocksource.h> +#endif /* CONFIG_GENERIC_GETTIMEOFDAY */ + +enum vdso_clock_mode { + VDSO_CLOCKMODE_NONE, +#ifdef CONFIG_GENERIC_GETTIMEOFDAY + VDSO_ARCH_CLOCKMODES, +#endif + VDSO_CLOCKMODE_MAX, + + /* Indicator for time namespace VDSO */ + VDSO_CLOCKMODE_TIMENS = INT_MAX +}; + +#endif /* __VDSO_CLOCKSOURCE_H */ diff --git a/include/vdso/const.h b/include/vdso/const.h new file mode 100644 index 000000000..94b385ad4 --- /dev/null +++ b/include/vdso/const.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_CONST_H +#define __VDSO_CONST_H + +#include <uapi/linux/const.h> + +#define UL(x) (_UL(x)) +#define ULL(x) (_ULL(x)) + +#endif /* __VDSO_CONST_H */ diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h new file mode 100644 index 000000000..73eb622e7 --- /dev/null +++ b/include/vdso/datapage.h @@ -0,0 +1,142 @@ +/* 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 */ diff --git a/include/vdso/helpers.h b/include/vdso/helpers.h new file mode 100644 index 000000000..9a2af9fca --- /dev/null +++ b/include/vdso/helpers.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_HELPERS_H +#define __VDSO_HELPERS_H + +#ifndef __ASSEMBLY__ + +#include <vdso/datapage.h> + +static __always_inline u32 vdso_read_begin(const struct vdso_data *vd) +{ + u32 seq; + + while (unlikely((seq = READ_ONCE(vd->seq)) & 1)) + cpu_relax(); + + smp_rmb(); + return seq; +} + +static __always_inline u32 vdso_read_retry(const struct vdso_data *vd, + u32 start) +{ + u32 seq; + + smp_rmb(); + seq = READ_ONCE(vd->seq); + return seq != start; +} + +static __always_inline void vdso_write_begin(struct vdso_data *vd) +{ + /* + * WRITE_ONCE it is required otherwise the compiler can validly tear + * updates to vd[x].seq and it is possible that the value seen by the + * reader it is inconsistent. + */ + WRITE_ONCE(vd[CS_HRES_COARSE].seq, vd[CS_HRES_COARSE].seq + 1); + WRITE_ONCE(vd[CS_RAW].seq, vd[CS_RAW].seq + 1); + smp_wmb(); +} + +static __always_inline void vdso_write_end(struct vdso_data *vd) +{ + smp_wmb(); + /* + * WRITE_ONCE it is required otherwise the compiler can validly tear + * updates to vd[x].seq and it is possible that the value seen by the + * reader it is inconsistent. + */ + WRITE_ONCE(vd[CS_HRES_COARSE].seq, vd[CS_HRES_COARSE].seq + 1); + WRITE_ONCE(vd[CS_RAW].seq, vd[CS_RAW].seq + 1); +} + +#endif /* !__ASSEMBLY__ */ + +#endif /* __VDSO_HELPERS_H */ diff --git a/include/vdso/jiffies.h b/include/vdso/jiffies.h new file mode 100644 index 000000000..2f9d596c8 --- /dev/null +++ b/include/vdso/jiffies.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_JIFFIES_H +#define __VDSO_JIFFIES_H + +#include <asm/param.h> /* for HZ */ +#include <vdso/time64.h> + +/* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */ +#define TICK_NSEC ((NSEC_PER_SEC+HZ/2)/HZ) + +#endif /* __VDSO_JIFFIES_H */ diff --git a/include/vdso/ktime.h b/include/vdso/ktime.h new file mode 100644 index 000000000..a0fd07239 --- /dev/null +++ b/include/vdso/ktime.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_KTIME_H +#define __VDSO_KTIME_H + +#include <vdso/jiffies.h> + +/* + * The resolution of the clocks. The resolution value is returned in + * the clock_getres() system call to give application programmers an + * idea of the (in)accuracy of timers. Timer values are rounded up to + * this resolution values. + */ +#define LOW_RES_NSEC TICK_NSEC +#define KTIME_LOW_RES (LOW_RES_NSEC) + +#endif /* __VDSO_KTIME_H */ diff --git a/include/vdso/limits.h b/include/vdso/limits.h new file mode 100644 index 000000000..0197888ad --- /dev/null +++ b/include/vdso/limits.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_LIMITS_H +#define __VDSO_LIMITS_H + +#define USHRT_MAX ((unsigned short)~0U) +#define SHRT_MAX ((short)(USHRT_MAX >> 1)) +#define SHRT_MIN ((short)(-SHRT_MAX - 1)) +#define INT_MAX ((int)(~0U >> 1)) +#define INT_MIN (-INT_MAX - 1) +#define UINT_MAX (~0U) +#define LONG_MAX ((long)(~0UL >> 1)) +#define LONG_MIN (-LONG_MAX - 1) +#define ULONG_MAX (~0UL) +#define LLONG_MAX ((long long)(~0ULL >> 1)) +#define LLONG_MIN (-LLONG_MAX - 1) +#define ULLONG_MAX (~0ULL) +#define UINTPTR_MAX ULONG_MAX + +#endif /* __VDSO_LIMITS_H */ diff --git a/include/vdso/math64.h b/include/vdso/math64.h new file mode 100644 index 000000000..7da703ee5 --- /dev/null +++ b/include/vdso/math64.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_MATH64_H +#define __VDSO_MATH64_H + +static __always_inline u32 +__iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder) +{ + u32 ret = 0; + + while (dividend >= divisor) { + /* The following asm() prevents the compiler from + optimising this loop into a modulo operation. */ + asm("" : "+rm"(dividend)); + + dividend -= divisor; + ret++; + } + + *remainder = dividend; + + return ret; +} + +#endif /* __VDSO_MATH64_H */ diff --git a/include/vdso/processor.h b/include/vdso/processor.h new file mode 100644 index 000000000..fbe8265ea --- /dev/null +++ b/include/vdso/processor.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 ARM Ltd. + */ +#ifndef __VDSO_PROCESSOR_H +#define __VDSO_PROCESSOR_H + +#ifndef __ASSEMBLY__ + +#include <asm/vdso/processor.h> + +#endif /* __ASSEMBLY__ */ + +#endif /* __VDSO_PROCESSOR_H */ diff --git a/include/vdso/time.h b/include/vdso/time.h new file mode 100644 index 000000000..739f53cd2 --- /dev/null +++ b/include/vdso/time.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_TIME_H +#define __VDSO_TIME_H + +#include <uapi/linux/types.h> + +struct timens_offset { + s64 sec; + u64 nsec; +}; + +#endif /* __VDSO_TIME_H */ diff --git a/include/vdso/time32.h b/include/vdso/time32.h new file mode 100644 index 000000000..fdf56f932 --- /dev/null +++ b/include/vdso/time32.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_TIME32_H +#define __VDSO_TIME32_H + +typedef s32 old_time32_t; + +struct old_timespec32 { + old_time32_t tv_sec; + s32 tv_nsec; +}; + +struct old_timeval32 { + old_time32_t tv_sec; + s32 tv_usec; +}; + +#endif /* __VDSO_TIME32_H */ diff --git a/include/vdso/time64.h b/include/vdso/time64.h new file mode 100644 index 000000000..b40cfa2aa --- /dev/null +++ b/include/vdso/time64.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_TIME64_H +#define __VDSO_TIME64_H + +/* Parameters used to convert the timespec values: */ +#define MSEC_PER_SEC 1000L +#define USEC_PER_MSEC 1000L +#define NSEC_PER_USEC 1000L +#define NSEC_PER_MSEC 1000000L +#define USEC_PER_SEC 1000000L +#define NSEC_PER_SEC 1000000000L +#define PSEC_PER_SEC 1000000000000LL +#define FSEC_PER_SEC 1000000000000000LL + +#endif /* __VDSO_TIME64_H */ diff --git a/include/vdso/vsyscall.h b/include/vdso/vsyscall.h new file mode 100644 index 000000000..b0fdc9c6b --- /dev/null +++ b/include/vdso/vsyscall.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_VSYSCALL_H +#define __VDSO_VSYSCALL_H + +#ifndef __ASSEMBLY__ + +#include <asm/vdso/vsyscall.h> + +unsigned long vdso_update_begin(void); +void vdso_update_end(unsigned long flags); + +#endif /* !__ASSEMBLY__ */ + +#endif /* __VDSO_VSYSCALL_H */ |