summaryrefslogtreecommitdiffstats
path: root/arch/sparc/vdso/vclock_gettime.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sparc/vdso/vclock_gettime.c')
-rw-r--r--arch/sparc/vdso/vclock_gettime.c373
1 files changed, 373 insertions, 0 deletions
diff --git a/arch/sparc/vdso/vclock_gettime.c b/arch/sparc/vdso/vclock_gettime.c
new file mode 100644
index 000000000..e794edde6
--- /dev/null
+++ b/arch/sparc/vdso/vclock_gettime.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2006 Andi Kleen, SUSE Labs.
+ *
+ * Fast user context implementation of clock_gettime, gettimeofday, and time.
+ *
+ * The code should have no internal unresolved relocations.
+ * Check with readelf after changing.
+ * Also alternative() doesn't work.
+ */
+/*
+ * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <linux/string.h>
+#include <asm/io.h>
+#include <asm/unistd.h>
+#include <asm/timex.h>
+#include <asm/clocksource.h>
+#include <asm/vvar.h>
+
+#ifdef CONFIG_SPARC64
+#define SYSCALL_STRING \
+ "ta 0x6d;" \
+ "bcs,a 1f;" \
+ " sub %%g0, %%o0, %%o0;" \
+ "1:"
+#else
+#define SYSCALL_STRING \
+ "ta 0x10;" \
+ "bcs,a 1f;" \
+ " sub %%g0, %%o0, %%o0;" \
+ "1:"
+#endif
+
+#define SYSCALL_CLOBBERS \
+ "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
+ "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
+ "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23", \
+ "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31", \
+ "f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46", \
+ "f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62", \
+ "cc", "memory"
+
+/*
+ * Compute the vvar page's address in the process address space, and return it
+ * as a pointer to the vvar_data.
+ */
+notrace static __always_inline struct vvar_data *get_vvar_data(void)
+{
+ unsigned long ret;
+
+ /*
+ * vdso data page is the first vDSO page so grab the PC
+ * and move up a page to get to the data page.
+ */
+ __asm__("rd %%pc, %0" : "=r" (ret));
+ ret &= ~(8192 - 1);
+ ret -= 8192;
+
+ return (struct vvar_data *) ret;
+}
+
+notrace static long vdso_fallback_gettime(long clock, struct __kernel_old_timespec *ts)
+{
+ register long num __asm__("g1") = __NR_clock_gettime;
+ register long o0 __asm__("o0") = clock;
+ register long o1 __asm__("o1") = (long) ts;
+
+ __asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
+ "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
+ return o0;
+}
+
+notrace static long vdso_fallback_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
+{
+ register long num __asm__("g1") = __NR_gettimeofday;
+ register long o0 __asm__("o0") = (long) tv;
+ register long o1 __asm__("o1") = (long) tz;
+
+ __asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
+ "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
+ return o0;
+}
+
+#ifdef CONFIG_SPARC64
+notrace static __always_inline u64 vread_tick(void)
+{
+ u64 ret;
+
+ __asm__ __volatile__("rd %%tick, %0" : "=r" (ret));
+ return ret;
+}
+
+notrace static __always_inline u64 vread_tick_stick(void)
+{
+ u64 ret;
+
+ __asm__ __volatile__("rd %%asr24, %0" : "=r" (ret));
+ return ret;
+}
+#else
+notrace static __always_inline u64 vread_tick(void)
+{
+ register unsigned long long ret asm("o4");
+
+ __asm__ __volatile__("rd %%tick, %L0\n\t"
+ "srlx %L0, 32, %H0"
+ : "=r" (ret));
+ return ret;
+}
+
+notrace static __always_inline u64 vread_tick_stick(void)
+{
+ register unsigned long long ret asm("o4");
+
+ __asm__ __volatile__("rd %%asr24, %L0\n\t"
+ "srlx %L0, 32, %H0"
+ : "=r" (ret));
+ return ret;
+}
+#endif
+
+notrace static __always_inline u64 vgetsns(struct vvar_data *vvar)
+{
+ u64 v;
+ u64 cycles;
+
+ cycles = vread_tick();
+ v = (cycles - vvar->clock.cycle_last) & vvar->clock.mask;
+ return v * vvar->clock.mult;
+}
+
+notrace static __always_inline u64 vgetsns_stick(struct vvar_data *vvar)
+{
+ u64 v;
+ u64 cycles;
+
+ cycles = vread_tick_stick();
+ v = (cycles - vvar->clock.cycle_last) & vvar->clock.mask;
+ return v * vvar->clock.mult;
+}
+
+notrace static __always_inline int do_realtime(struct vvar_data *vvar,
+ struct __kernel_old_timespec *ts)
+{
+ unsigned long seq;
+ u64 ns;
+
+ do {
+ seq = vvar_read_begin(vvar);
+ ts->tv_sec = vvar->wall_time_sec;
+ ns = vvar->wall_time_snsec;
+ ns += vgetsns(vvar);
+ ns >>= vvar->clock.shift;
+ } while (unlikely(vvar_read_retry(vvar, seq)));
+
+ ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
+ ts->tv_nsec = ns;
+
+ return 0;
+}
+
+notrace static __always_inline int do_realtime_stick(struct vvar_data *vvar,
+ struct __kernel_old_timespec *ts)
+{
+ unsigned long seq;
+ u64 ns;
+
+ do {
+ seq = vvar_read_begin(vvar);
+ ts->tv_sec = vvar->wall_time_sec;
+ ns = vvar->wall_time_snsec;
+ ns += vgetsns_stick(vvar);
+ ns >>= vvar->clock.shift;
+ } while (unlikely(vvar_read_retry(vvar, seq)));
+
+ ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
+ ts->tv_nsec = ns;
+
+ return 0;
+}
+
+notrace static __always_inline int do_monotonic(struct vvar_data *vvar,
+ struct __kernel_old_timespec *ts)
+{
+ unsigned long seq;
+ u64 ns;
+
+ do {
+ seq = vvar_read_begin(vvar);
+ ts->tv_sec = vvar->monotonic_time_sec;
+ ns = vvar->monotonic_time_snsec;
+ ns += vgetsns(vvar);
+ ns >>= vvar->clock.shift;
+ } while (unlikely(vvar_read_retry(vvar, seq)));
+
+ ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
+ ts->tv_nsec = ns;
+
+ return 0;
+}
+
+notrace static __always_inline int do_monotonic_stick(struct vvar_data *vvar,
+ struct __kernel_old_timespec *ts)
+{
+ unsigned long seq;
+ u64 ns;
+
+ do {
+ seq = vvar_read_begin(vvar);
+ ts->tv_sec = vvar->monotonic_time_sec;
+ ns = vvar->monotonic_time_snsec;
+ ns += vgetsns_stick(vvar);
+ ns >>= vvar->clock.shift;
+ } while (unlikely(vvar_read_retry(vvar, seq)));
+
+ ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
+ ts->tv_nsec = ns;
+
+ return 0;
+}
+
+notrace static int do_realtime_coarse(struct vvar_data *vvar,
+ struct __kernel_old_timespec *ts)
+{
+ unsigned long seq;
+
+ do {
+ seq = vvar_read_begin(vvar);
+ ts->tv_sec = vvar->wall_time_coarse_sec;
+ ts->tv_nsec = vvar->wall_time_coarse_nsec;
+ } while (unlikely(vvar_read_retry(vvar, seq)));
+ return 0;
+}
+
+notrace static int do_monotonic_coarse(struct vvar_data *vvar,
+ struct __kernel_old_timespec *ts)
+{
+ unsigned long seq;
+
+ do {
+ seq = vvar_read_begin(vvar);
+ ts->tv_sec = vvar->monotonic_time_coarse_sec;
+ ts->tv_nsec = vvar->monotonic_time_coarse_nsec;
+ } while (unlikely(vvar_read_retry(vvar, seq)));
+
+ return 0;
+}
+
+notrace int
+__vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts)
+{
+ struct vvar_data *vvd = get_vvar_data();
+
+ switch (clock) {
+ case CLOCK_REALTIME:
+ if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
+ break;
+ return do_realtime(vvd, ts);
+ case CLOCK_MONOTONIC:
+ if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
+ break;
+ return do_monotonic(vvd, ts);
+ case CLOCK_REALTIME_COARSE:
+ return do_realtime_coarse(vvd, ts);
+ case CLOCK_MONOTONIC_COARSE:
+ return do_monotonic_coarse(vvd, ts);
+ }
+ /*
+ * Unknown clock ID ? Fall back to the syscall.
+ */
+ return vdso_fallback_gettime(clock, ts);
+}
+int
+clock_gettime(clockid_t, struct __kernel_old_timespec *)
+ __attribute__((weak, alias("__vdso_clock_gettime")));
+
+notrace int
+__vdso_clock_gettime_stick(clockid_t clock, struct __kernel_old_timespec *ts)
+{
+ struct vvar_data *vvd = get_vvar_data();
+
+ switch (clock) {
+ case CLOCK_REALTIME:
+ if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
+ break;
+ return do_realtime_stick(vvd, ts);
+ case CLOCK_MONOTONIC:
+ if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
+ break;
+ return do_monotonic_stick(vvd, ts);
+ case CLOCK_REALTIME_COARSE:
+ return do_realtime_coarse(vvd, ts);
+ case CLOCK_MONOTONIC_COARSE:
+ return do_monotonic_coarse(vvd, ts);
+ }
+ /*
+ * Unknown clock ID ? Fall back to the syscall.
+ */
+ return vdso_fallback_gettime(clock, ts);
+}
+
+notrace int
+__vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
+{
+ struct vvar_data *vvd = get_vvar_data();
+
+ if (likely(vvd->vclock_mode != VCLOCK_NONE)) {
+ if (likely(tv != NULL)) {
+ union tstv_t {
+ struct __kernel_old_timespec ts;
+ struct __kernel_old_timeval tv;
+ } *tstv = (union tstv_t *) tv;
+ do_realtime(vvd, &tstv->ts);
+ /*
+ * Assign before dividing to ensure that the division is
+ * done in the type of tv_usec, not tv_nsec.
+ *
+ * There cannot be > 1 billion usec in a second:
+ * do_realtime() has already distributed such overflow
+ * into tv_sec. So we can assign it to an int safely.
+ */
+ tstv->tv.tv_usec = tstv->ts.tv_nsec;
+ tstv->tv.tv_usec /= 1000;
+ }
+ if (unlikely(tz != NULL)) {
+ /* Avoid memcpy. Some old compilers fail to inline it */
+ tz->tz_minuteswest = vvd->tz_minuteswest;
+ tz->tz_dsttime = vvd->tz_dsttime;
+ }
+ return 0;
+ }
+ return vdso_fallback_gettimeofday(tv, tz);
+}
+int
+gettimeofday(struct __kernel_old_timeval *, struct timezone *)
+ __attribute__((weak, alias("__vdso_gettimeofday")));
+
+notrace int
+__vdso_gettimeofday_stick(struct __kernel_old_timeval *tv, struct timezone *tz)
+{
+ struct vvar_data *vvd = get_vvar_data();
+
+ if (likely(vvd->vclock_mode != VCLOCK_NONE)) {
+ if (likely(tv != NULL)) {
+ union tstv_t {
+ struct __kernel_old_timespec ts;
+ struct __kernel_old_timeval tv;
+ } *tstv = (union tstv_t *) tv;
+ do_realtime_stick(vvd, &tstv->ts);
+ /*
+ * Assign before dividing to ensure that the division is
+ * done in the type of tv_usec, not tv_nsec.
+ *
+ * There cannot be > 1 billion usec in a second:
+ * do_realtime() has already distributed such overflow
+ * into tv_sec. So we can assign it to an int safely.
+ */
+ tstv->tv.tv_usec = tstv->ts.tv_nsec;
+ tstv->tv.tv_usec /= 1000;
+ }
+ if (unlikely(tz != NULL)) {
+ /* Avoid memcpy. Some old compilers fail to inline it */
+ tz->tz_minuteswest = vvd->tz_minuteswest;
+ tz->tz_dsttime = vvd->tz_dsttime;
+ }
+ return 0;
+ }
+ return vdso_fallback_gettimeofday(tv, tz);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-08 07:36:19 +0000