1 files changed, 264 insertions, 0 deletions
diff --git a/arch/sparc/vdso/vclock_gettime.c b/arch/sparc/vdso/vclock_gettime.c
new file mode 100644
index 000000000000..3feb3d960ca5
--- /dev/null
+++ b/arch/sparc/vdso/vclock_gettime.c
@@ -0,0 +1,264 @@
+/*
+ * Copyright 2006 Andi Kleen, SUSE Labs.
+ * Subject to the GNU Public License, v.2
+ *
+ * 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.
+ */
+
+/* Disable profiling for userspace code: */
+#ifndef	DISABLE_BRANCH_PROFILING
+#define	DISABLE_BRANCH_PROFILING
+#endif
+
+#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>
+
+#undef	TICK_PRIV_BIT
+#ifdef	CONFIG_SPARC64
+#define	TICK_PRIV_BIT	(1UL << 63)
+#else
+#define	TICK_PRIV_BIT	(1ULL << 63)
+#endif
+
+#define SYSCALL_STRING							\
+	"ta	0x6d;"							\
+	"sub	%%g0, %%o0, %%o0;"					\
+
+#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.
+ */
+static notrace noinline struct vvar_data *
+get_vvar_data(void)
+{
+	unsigned long ret;
+
+	/*
+	 * vdso data page is the first vDSO page so grab the return address
+	 * and move up a page to get to the data page.
+	 */
+	ret = (unsigned long)__builtin_return_address(0);
+	ret &= ~(8192 - 1);
+	ret -= 8192;
+
+	return (struct vvar_data *) ret;
+}
+
+static notrace long
+vdso_fallback_gettime(long clock, struct 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;
+}
+
+static notrace __always_inline long
+vdso_fallback_gettimeofday(struct 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
+static notrace noinline u64
+vread_tick(void) {
+	u64	ret;
+
+	__asm__ __volatile__("rd	%%asr24, %0 \n"
+			     ".section	.vread_tick_patch, \"ax\" \n"
+			     "rd	%%tick, %0 \n"
+			     ".previous \n"
+			     : "=&r" (ret));
+	return ret & ~TICK_PRIV_BIT;
+}
+#else
+static notrace noinline u64
+vread_tick(void)
+{
+	unsigned int lo, hi;
+
+	__asm__ __volatile__("rd	%%asr24, %%g1\n\t"
+			     "srlx	%%g1, 32, %1\n\t"
+			     "srl	%%g1, 0, %0\n"
+			     ".section	.vread_tick_patch, \"ax\" \n"
+			     "rd	%%tick, %%g1\n"
+			     ".previous \n"
+			     : "=&r" (lo), "=&r" (hi)
+			     :
+			     : "g1");
+	return lo | ((u64)hi << 32);
+}
+#endif
+
+static notrace 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;
+}
+
+static notrace noinline int
+do_realtime(struct vvar_data *vvar, struct timespec *ts)
+{
+	unsigned long seq;
+	u64 ns;
+
+	ts->tv_nsec = 0;
+	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)));
+
+	timespec_add_ns(ts, ns);
+
+	return 0;
+}
+
+static notrace noinline int
+do_monotonic(struct vvar_data *vvar, struct timespec *ts)
+{
+	unsigned long seq;
+	u64 ns;
+
+	ts->tv_nsec = 0;
+	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)));
+
+	timespec_add_ns(ts, ns);
+
+	return 0;
+}
+
+static notrace noinline int
+do_realtime_coarse(struct vvar_data *vvar, struct 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;
+}
+
+static notrace noinline int
+do_monotonic_coarse(struct vvar_data *vvar, struct 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 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 timespec *)
+	__attribute__((weak, alias("__vdso_clock_gettime")));
+
+notrace int
+__vdso_gettimeofday(struct 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 timespec ts;
+				struct 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 timeval *, struct timezone *)
+	__attribute__((weak, alias("__vdso_gettimeofday")));