// SPDX-License-Identifier: GPL-2.0
|
/*
|
* Generic userspace implementations of gettimeofday() and similar.
|
*/
|
#include <vdso/datapage.h>
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#include <vdso/helpers.h>
|
|
static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
|
struct __kernel_timespec *ts);
|
|
#ifndef vdso_clocksource_ok
|
static inline bool vdso_clocksource_ok(const struct vdso_data *vd)
|
{
|
return vd->clock_mode != VDSO_CLOCKMODE_NONE;
|
}
|
#endif
|
|
#ifndef vdso_cycles_ok
|
static inline bool vdso_cycles_ok(u64 cycles)
|
{
|
return true;
|
}
|
#endif
|
|
#if defined(CONFIG_GENERIC_CLOCKSOURCE_VDSO) && !defined(BUILD_VDSO32)
|
|
#include <linux/fcntl.h>
|
#include <linux/io.h>
|
#include <linux/ioctl.h>
|
#include <uapi/linux/clocksource.h>
|
|
static notrace u64 readl_mmio_up(const struct clksrc_info *vinfo)
|
{
|
const struct clksrc_user_mmio_info *info = &vinfo->mmio;
|
return readl_relaxed(info->reg_lower);
|
}
|
|
static notrace u64 readl_mmio_down(const struct clksrc_info *vinfo)
|
{
|
const struct clksrc_user_mmio_info *info = &vinfo->mmio;
|
return ~(u64)readl_relaxed(info->reg_lower) & info->mask_lower;
|
}
|
|
static notrace u64 readw_mmio_up(const struct clksrc_info *vinfo)
|
{
|
const struct clksrc_user_mmio_info *info = &vinfo->mmio;
|
return readw_relaxed(info->reg_lower);
|
}
|
|
static notrace u64 readw_mmio_down(const struct clksrc_info *vinfo)
|
{
|
const struct clksrc_user_mmio_info *info = &vinfo->mmio;
|
return ~(u64)readl_relaxed(info->reg_lower) & info->mask_lower;
|
}
|
|
static notrace u64 readl_dmmio_up(const struct clksrc_info *vinfo)
|
{
|
const struct clksrc_user_mmio_info *info = &vinfo->mmio;
|
void __iomem *reg_lower, *reg_upper;
|
u32 upper, old_upper, lower;
|
|
reg_lower = info->reg_lower;
|
reg_upper = info->reg_upper;
|
|
upper = readl_relaxed(reg_upper);
|
do {
|
old_upper = upper;
|
lower = readl_relaxed(reg_lower);
|
upper = readl_relaxed(reg_upper);
|
} while (upper != old_upper);
|
|
return (((u64)upper) << info->bits_lower) | lower;
|
}
|
|
static notrace u64 readw_dmmio_up(const struct clksrc_info *vinfo)
|
{
|
const struct clksrc_user_mmio_info *info = &vinfo->mmio;
|
void __iomem *reg_lower, *reg_upper;
|
u16 upper, old_upper, lower;
|
|
reg_lower = info->reg_lower;
|
reg_upper = info->reg_upper;
|
|
upper = readw_relaxed(reg_upper);
|
do {
|
old_upper = upper;
|
lower = readw_relaxed(reg_lower);
|
upper = readw_relaxed(reg_upper);
|
} while (upper != old_upper);
|
|
return (((u64)upper) << info->bits_lower) | lower;
|
}
|
|
static notrace __cold vdso_read_cycles_t *get_mmio_read_cycles(unsigned int type)
|
{
|
switch (type) {
|
case CLKSRC_MMIO_L_UP:
|
return &readl_mmio_up;
|
case CLKSRC_MMIO_L_DOWN:
|
return &readl_mmio_down;
|
case CLKSRC_MMIO_W_UP:
|
return &readw_mmio_up;
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case CLKSRC_MMIO_W_DOWN:
|
return &readw_mmio_down;
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case CLKSRC_DMMIO_L_UP:
|
return &readl_dmmio_up;
|
case CLKSRC_DMMIO_W_UP:
|
return &readw_dmmio_up;
|
default:
|
return NULL;
|
}
|
}
|
|
static __always_inline u16 to_cs_type(u32 cs_type_seq)
|
{
|
return cs_type_seq >> 16;
|
}
|
|
static __always_inline u16 to_seq(u32 cs_type_seq)
|
{
|
return cs_type_seq;
|
}
|
|
static __always_inline u32 to_cs_type_seq(u16 type, u16 seq)
|
{
|
return (u32)type << 16U | seq;
|
}
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|
static notrace noinline __cold
|
void map_clocksource(const struct vdso_data *vd, struct vdso_priv *vp,
|
u32 seq, u32 new_cs_type_seq)
|
{
|
vdso_read_cycles_t *read_cycles = NULL;
|
u32 new_cs_seq, new_cs_type;
|
struct clksrc_info *info;
|
int fd, ret;
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|
new_cs_seq = to_seq(new_cs_type_seq);
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new_cs_type = to_cs_type(new_cs_type_seq);
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info = &vp->clksrc_info[new_cs_type];
|
|
if (new_cs_type < CLOCKSOURCE_VDSO_MMIO)
|
goto done;
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|
fd = clock_open_device(vd->cs_mmdev, O_RDONLY);
|
if (fd < 0)
|
goto fallback_to_syscall;
|
|
if (vdso_read_retry(vd, seq)) {
|
vdso_read_begin(vd);
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if (to_seq(vd->cs_type_seq) != new_cs_seq) {
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/*
|
* cs_mmdev no longer corresponds to
|
* vd->cs_type_seq.
|
*/
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clock_close_device(fd);
|
return;
|
}
|
}
|
|
ret = clock_ioctl_device(fd, CLKSRC_USER_MMIO_MAP, (long)&info->mmio);
|
clock_close_device(fd);
|
if (ret < 0)
|
goto fallback_to_syscall;
|
|
read_cycles = get_mmio_read_cycles(info->mmio.type);
|
if (read_cycles == NULL) /* Mmhf, misconfigured. */
|
goto fallback_to_syscall;
|
done:
|
info->read_cycles = read_cycles;
|
smp_wmb();
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new_cs_type_seq = to_cs_type_seq(new_cs_type, new_cs_seq);
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WRITE_ONCE(vp->current_cs_type_seq, new_cs_type_seq);
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|
return;
|
|
fallback_to_syscall:
|
new_cs_type = CLOCKSOURCE_VDSO_NONE;
|
info = &vp->clksrc_info[new_cs_type];
|
goto done;
|
}
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|
static inline notrace
|
bool get_hw_counter(const struct vdso_data *vd, u32 *r_seq, u64 *cycles)
|
{
|
const struct clksrc_info *info;
|
struct vdso_priv *vp;
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u32 seq, cs_type_seq;
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unsigned int cs;
|
|
vp = __arch_get_vdso_priv();
|
|
for (;;) {
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seq = vdso_read_begin(vd);
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cs_type_seq = READ_ONCE(vp->current_cs_type_seq);
|
if (likely(to_seq(cs_type_seq) == to_seq(vd->cs_type_seq)))
|
break;
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map_clocksource(vd, vp, seq, vd->cs_type_seq);
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}
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|
switch (to_cs_type(cs_type_seq)) {
|
case CLOCKSOURCE_VDSO_NONE:
|
return false; /* Use fallback. */
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case CLOCKSOURCE_VDSO_ARCHITECTED:
|
if (unlikely(!vdso_clocksource_ok(vd)))
|
return false;
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*cycles = __arch_get_hw_counter(vd->clock_mode, vd);
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if (unlikely(!vdso_cycles_ok(*cycles)))
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return false;
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break;
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default:
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cs = to_cs_type(READ_ONCE(cs_type_seq));
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info = &vp->clksrc_info[cs];
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*cycles = info->read_cycles(info);
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break;
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}
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*r_seq = seq;
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|
return true;
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}
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|
#else
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|
static inline notrace
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bool get_hw_counter(const struct vdso_data *vd, u32 *r_seq, u64 *cycles)
|
{
|
*r_seq = vdso_read_begin(vd);
|
|
/*
|
* CAUTION: checking the clocksource mode must happen inside
|
* the seqlocked section.
|
*/
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if (unlikely(!vdso_clocksource_ok(vd)))
|
return false;
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*cycles = __arch_get_hw_counter(vd->clock_mode, vd);
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if (unlikely(!vdso_cycles_ok(*cycles)))
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return false;
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|
return true;
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}
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#endif /* CONFIG_GENERIC_CLOCKSOURCE_VDSO */
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#ifndef vdso_calc_delta
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/*
|
* Default implementation which works for all sane clocksources. That
|
* obviously excludes x86/TSC.
|
*/
|
static __always_inline
|
u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
|
{
|
return ((cycles - last) & mask) * mult;
|
}
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#endif
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#ifndef vdso_shift_ns
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static __always_inline u64 vdso_shift_ns(u64 ns, u32 shift)
|
{
|
return ns >> shift;
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}
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#endif
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#ifndef __arch_vdso_hres_capable
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static inline bool __arch_vdso_hres_capable(void)
|
{
|
return true;
|
}
|
#endif
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#ifdef CONFIG_TIME_NS
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static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
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struct __kernel_timespec *ts)
|
{
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const struct vdso_data *vd = __arch_get_timens_vdso_data();
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const struct timens_offset *offs = &vdns->offset[clk];
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const struct vdso_timestamp *vdso_ts;
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u64 cycles, last, ns;
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u32 seq;
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s64 sec;
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if (clk != CLOCK_MONOTONIC_RAW)
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vd = &vd[CS_HRES_COARSE];
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else
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vd = &vd[CS_RAW];
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vdso_ts = &vd->basetime[clk];
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do {
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if (!get_hw_counter(vd, &seq, &cycles))
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return -1;
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ns = vdso_ts->nsec;
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last = vd->cycle_last;
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ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
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ns = vdso_shift_ns(ns, vd->shift);
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sec = vdso_ts->sec;
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} while (unlikely(vdso_read_retry(vd, seq)));
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/* Add the namespace offset */
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sec += offs->sec;
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ns += offs->nsec;
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/*
|
* Do this outside the loop: a race inside the loop could result
|
* in __iter_div_u64_rem() being extremely slow.
|
*/
|
ts->tv_sec = sec + __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
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ts->tv_nsec = ns;
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|
return 0;
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}
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#else
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static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
|
{
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return NULL;
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}
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static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
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struct __kernel_timespec *ts)
|
{
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return -EINVAL;
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}
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#endif
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static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
|
struct __kernel_timespec *ts)
|
{
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const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
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u64 cycles, last, sec, ns;
|
u32 seq;
|
|
/* Allows to compile the high resolution parts out */
|
if (!__arch_vdso_hres_capable())
|
return -1;
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|
do {
|
/*
|
* Open coded to handle VDSO_CLOCKMODE_TIMENS. Time
|
* namespace enabled tasks have a special VVAR page
|
* installed which has vd->seq set to 1 and
|
* vd->clock_mode set to VDSO_CLOCKMODE_TIMENS. For
|
* non time namespace affected tasks this does not
|
* affect performance because if vd->seq is odd,
|
* i.e. a concurrent update is in progress the extra
|
* check for vd->clock_mode is just a few extra
|
* instructions while spin waiting for vd->seq to
|
* become even again.
|
*/
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while (unlikely((seq = READ_ONCE(vd->seq)) & 1)) {
|
if (IS_ENABLED(CONFIG_TIME_NS) &&
|
vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
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return do_hres_timens(vd, clk, ts);
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cpu_relax();
|
}
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|
smp_rmb();
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if (!get_hw_counter(vd, &seq, &cycles))
|
return -1;
|
|
ns = vdso_ts->nsec;
|
last = vd->cycle_last;
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ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
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ns = vdso_shift_ns(ns, vd->shift);
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sec = vdso_ts->sec;
|
} while (unlikely(vdso_read_retry(vd, seq)));
|
|
/*
|
* Do this outside the loop: a race inside the loop could result
|
* in __iter_div_u64_rem() being extremely slow.
|
*/
|
ts->tv_sec = sec + __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
|
ts->tv_nsec = ns;
|
|
return 0;
|
}
|
|
#ifdef CONFIG_TIME_NS
|
static __always_inline int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
|
struct __kernel_timespec *ts)
|
{
|
const struct vdso_data *vd = __arch_get_timens_vdso_data();
|
const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
|
const struct timens_offset *offs = &vdns->offset[clk];
|
u64 nsec;
|
s64 sec;
|
s32 seq;
|
|
do {
|
seq = vdso_read_begin(vd);
|
sec = vdso_ts->sec;
|
nsec = vdso_ts->nsec;
|
} while (unlikely(vdso_read_retry(vd, seq)));
|
|
/* Add the namespace offset */
|
sec += offs->sec;
|
nsec += offs->nsec;
|
|
/*
|
* Do this outside the loop: a race inside the loop could result
|
* in __iter_div_u64_rem() being extremely slow.
|
*/
|
ts->tv_sec = sec + __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec);
|
ts->tv_nsec = nsec;
|
return 0;
|
}
|
#else
|
static __always_inline int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
|
struct __kernel_timespec *ts)
|
{
|
return -1;
|
}
|
#endif
|
|
static __always_inline int do_coarse(const struct vdso_data *vd, clockid_t clk,
|
struct __kernel_timespec *ts)
|
{
|
const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
|
u32 seq;
|
|
do {
|
/*
|
* Open coded to handle VDSO_CLOCK_TIMENS. See comment in
|
* do_hres().
|
*/
|
while ((seq = READ_ONCE(vd->seq)) & 1) {
|
if (IS_ENABLED(CONFIG_TIME_NS) &&
|
vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
|
return do_coarse_timens(vd, clk, ts);
|
cpu_relax();
|
}
|
smp_rmb();
|
|
ts->tv_sec = vdso_ts->sec;
|
ts->tv_nsec = vdso_ts->nsec;
|
} while (unlikely(vdso_read_retry(vd, seq)));
|
|
return 0;
|
}
|
|
static __always_inline int
|
__cvdso_clock_gettime_common(const struct vdso_data *vd, clockid_t clock,
|
struct __kernel_timespec *ts)
|
{
|
u32 msk;
|
|
/* Check for negative values or invalid clocks */
|
if (unlikely((u32) clock >= MAX_CLOCKS))
|
return -1;
|
|
/*
|
* Convert the clockid to a bitmask and use it to check which
|
* clocks are handled in the VDSO directly.
|
*/
|
msk = 1U << clock;
|
if (likely(msk & VDSO_HRES))
|
vd = &vd[CS_HRES_COARSE];
|
else if (msk & VDSO_COARSE)
|
return do_coarse(&vd[CS_HRES_COARSE], clock, ts);
|
else if (msk & VDSO_RAW)
|
vd = &vd[CS_RAW];
|
else
|
return -1;
|
|
return do_hres(vd, clock, ts);
|
}
|
|
static __maybe_unused int
|
__cvdso_clock_gettime_data(const struct vdso_data *vd, clockid_t clock,
|
struct __kernel_timespec *ts)
|
{
|
int ret = __cvdso_clock_gettime_common(vd, clock, ts);
|
|
if (unlikely(ret))
|
return clock_gettime_fallback(clock, ts);
|
return 0;
|
}
|
|
static __maybe_unused int
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__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
|
{
|
return __cvdso_clock_gettime_data(__arch_get_vdso_data(), clock, ts);
|
}
|
|
#ifdef BUILD_VDSO32
|
static __maybe_unused int
|
__cvdso_clock_gettime32_data(const struct vdso_data *vd, clockid_t clock,
|
struct old_timespec32 *res)
|
{
|
struct __kernel_timespec ts;
|
int ret;
|
|
ret = __cvdso_clock_gettime_common(vd, clock, &ts);
|
|
if (unlikely(ret))
|
return clock_gettime32_fallback(clock, res);
|
|
/* For ret == 0 */
|
res->tv_sec = ts.tv_sec;
|
res->tv_nsec = ts.tv_nsec;
|
|
return ret;
|
}
|
|
static __maybe_unused int
|
__cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res)
|
{
|
return __cvdso_clock_gettime32_data(__arch_get_vdso_data(), clock, res);
|
}
|
#endif /* BUILD_VDSO32 */
|
|
static __maybe_unused int
|
__cvdso_gettimeofday_data(const struct vdso_data *vd,
|
struct __kernel_old_timeval *tv, struct timezone *tz)
|
{
|
|
if (likely(tv != NULL)) {
|
struct __kernel_timespec ts;
|
|
if (do_hres(&vd[CS_HRES_COARSE], CLOCK_REALTIME, &ts))
|
return gettimeofday_fallback(tv, tz);
|
|
tv->tv_sec = ts.tv_sec;
|
tv->tv_usec = (u32)ts.tv_nsec / NSEC_PER_USEC;
|
}
|
|
if (unlikely(tz != NULL)) {
|
if (IS_ENABLED(CONFIG_TIME_NS) &&
|
vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
|
vd = __arch_get_timens_vdso_data();
|
|
tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
|
tz->tz_dsttime = vd[CS_HRES_COARSE].tz_dsttime;
|
}
|
|
return 0;
|
}
|
|
static __maybe_unused int
|
__cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
|
{
|
return __cvdso_gettimeofday_data(__arch_get_vdso_data(), tv, tz);
|
}
|
|
#ifdef VDSO_HAS_TIME
|
static __maybe_unused __kernel_old_time_t
|
__cvdso_time_data(const struct vdso_data *vd, __kernel_old_time_t *time)
|
{
|
__kernel_old_time_t t;
|
|
if (IS_ENABLED(CONFIG_TIME_NS) &&
|
vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
|
vd = __arch_get_timens_vdso_data();
|
|
t = READ_ONCE(vd[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec);
|
|
if (time)
|
*time = t;
|
|
return t;
|
}
|
|
static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *time)
|
{
|
return __cvdso_time_data(__arch_get_vdso_data(), time);
|
}
|
#endif /* VDSO_HAS_TIME */
|
|
#ifdef VDSO_HAS_CLOCK_GETRES
|
static __maybe_unused
|
int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock,
|
struct __kernel_timespec *res)
|
{
|
u32 msk;
|
u64 ns;
|
|
/* Check for negative values or invalid clocks */
|
if (unlikely((u32) clock >= MAX_CLOCKS))
|
return -1;
|
|
if (IS_ENABLED(CONFIG_TIME_NS) &&
|
vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
|
vd = __arch_get_timens_vdso_data();
|
|
/*
|
* Convert the clockid to a bitmask and use it to check which
|
* clocks are handled in the VDSO directly.
|
*/
|
msk = 1U << clock;
|
if (msk & (VDSO_HRES | VDSO_RAW)) {
|
/*
|
* Preserves the behaviour of posix_get_hrtimer_res().
|
*/
|
ns = READ_ONCE(vd[CS_HRES_COARSE].hrtimer_res);
|
} else if (msk & VDSO_COARSE) {
|
/*
|
* Preserves the behaviour of posix_get_coarse_res().
|
*/
|
ns = LOW_RES_NSEC;
|
} else {
|
return -1;
|
}
|
|
if (likely(res)) {
|
res->tv_sec = 0;
|
res->tv_nsec = ns;
|
}
|
return 0;
|
}
|
|
static __maybe_unused
|
int __cvdso_clock_getres_data(const struct vdso_data *vd, clockid_t clock,
|
struct __kernel_timespec *res)
|
{
|
int ret = __cvdso_clock_getres_common(vd, clock, res);
|
|
if (unlikely(ret))
|
return clock_getres_fallback(clock, res);
|
return 0;
|
}
|
|
static __maybe_unused
|
int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res)
|
{
|
return __cvdso_clock_getres_data(__arch_get_vdso_data(), clock, res);
|
}
|
|
#ifdef BUILD_VDSO32
|
static __maybe_unused int
|
__cvdso_clock_getres_time32_data(const struct vdso_data *vd, clockid_t clock,
|
struct old_timespec32 *res)
|
{
|
struct __kernel_timespec ts;
|
int ret;
|
|
ret = __cvdso_clock_getres_common(vd, clock, &ts);
|
|
if (unlikely(ret))
|
return clock_getres32_fallback(clock, res);
|
|
if (likely(res)) {
|
res->tv_sec = ts.tv_sec;
|
res->tv_nsec = ts.tv_nsec;
|
}
|
return ret;
|
}
|
|
static __maybe_unused int
|
__cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res)
|
{
|
return __cvdso_clock_getres_time32_data(__arch_get_vdso_data(),
|
clock, res);
|
}
|
#endif /* BUILD_VDSO32 */
|
#endif /* VDSO_HAS_CLOCK_GETRES */
|
