Open source GPL/LGPL release

drivers/gpu/nvgpu/os/linux/timers.c

@@ -0,0 +1,299 @@
+/*
+ * Copyright (c) 2016-2020, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/ktime.h>
+#include <linux/delay.h>
+
+#include <nvgpu/timers.h>
+#include <nvgpu/soc.h>
+#include <nvgpu/gk20a.h>
+
+#include "platform_gk20a.h"
+
+/*
+ * Returns 1 if the platform is pre-Si and should ignore the timeout checking.
+ * Setting %NVGPU_TIMER_NO_PRE_SI will make this always return 0 (i.e do the
+ * timeout check regardless of platform).
+ */
+static int nvgpu_timeout_is_pre_silicon(struct nvgpu_timeout *timeout)
+{
+	if (timeout->flags & NVGPU_TIMER_NO_PRE_SI)
+		return 0;
+
+	return !nvgpu_platform_is_silicon(timeout->g);
+}
+
+/**
+ * nvgpu_timeout_init - Init timer.
+ *
+ * @g        - nvgpu device.
+ * @timeout  - The timer.
+ * @duration - Timeout in milliseconds or number of retries.
+ * @flags    - Flags for timer.
+ *
+ * This configures the timeout to start the timeout duration now, i.e: when this
+ * function is called. Available flags to pass to @flags:
+ *
+ *   %NVGPU_TIMER_CPU_TIMER
+ *   %NVGPU_TIMER_RETRY_TIMER
+ *   %NVGPU_TIMER_NO_PRE_SI
+ *   %NVGPU_TIMER_SILENT_TIMEOUT
+ *
+ * If neither %NVGPU_TIMER_CPU_TIMER or %NVGPU_TIMER_RETRY_TIMER is passed then
+ * a CPU timer is used by default.
+ */
+int nvgpu_timeout_init(struct gk20a *g, struct nvgpu_timeout *timeout,
+		       u32 duration, unsigned long flags)
+{
+	if (flags & ~NVGPU_TIMER_FLAG_MASK)
+		return -EINVAL;
+
+	(void) memset(timeout, 0, sizeof(*timeout));
+
+	timeout->g = g;
+	timeout->flags = flags;
+
+	if (flags & NVGPU_TIMER_RETRY_TIMER)
+		timeout->retries.max_attempts = duration;
+	else
+		timeout->time = ktime_to_ns(ktime_add_ns(ktime_get(),
+					(s64)NSEC_PER_MSEC * duration));
+
+	return 0;
+}
+
+static int nvgpu_timeout_expired_msg_cpu(struct nvgpu_timeout *timeout,
+					 void *caller,
+					 const char *fmt, va_list args)
+{
+	struct gk20a *g = timeout->g;
+	ktime_t now = ktime_get();
+
+	if (nvgpu_timeout_is_pre_silicon(timeout))
+		return 0;
+
+	if (ktime_after(now, ns_to_ktime(timeout->time))) {
+		if (!(timeout->flags & NVGPU_TIMER_SILENT_TIMEOUT)) {
+			char buf[128];
+
+			(void) vsnprintf(buf, sizeof(buf), fmt, args);
+
+			nvgpu_err(g, "Timeout detected @ %pF %s", caller, buf);
+		}
+
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int nvgpu_timeout_expired_msg_retry(struct nvgpu_timeout *timeout,
+					   void *caller,
+					   const char *fmt, va_list args)
+{
+	struct gk20a *g = timeout->g;
+
+	if (nvgpu_timeout_is_pre_silicon(timeout))
+		return 0;
+
+	if (timeout->retries.attempted >= timeout->retries.max_attempts) {
+		if (!(timeout->flags & NVGPU_TIMER_SILENT_TIMEOUT)) {
+			char buf[128];
+
+			(void) vsnprintf(buf, sizeof(buf), fmt, args);
+
+			nvgpu_err(g, "No more retries @ %pF %s", caller, buf);
+		}
+
+		return -ETIMEDOUT;
+	}
+
+	timeout->retries.attempted++;
+
+	return 0;
+}
+
+/**
+ * nvgpu_timeout_expired_msg_impl - Check if a timeout has expired.
+ *
+ * @timeout - The timeout to check.
+ * @caller  - Address of the caller of this function.
+ * @fmt     - The fmt string.
+ *
+ * Returns -ETIMEDOUT if the timeout has expired, 0 otherwise.
+ *
+ * If a timeout occurs and %NVGPU_TIMER_SILENT_TIMEOUT is not set in the timeout
+ * then a message is printed based on %fmt.
+ */
+int nvgpu_timeout_expired_msg_impl(struct nvgpu_timeout *timeout,
+			      void *caller, const char *fmt, ...)
+{
+	int ret;
+	va_list args;
+
+	va_start(args, fmt);
+	if (timeout->flags & NVGPU_TIMER_RETRY_TIMER)
+		ret = nvgpu_timeout_expired_msg_retry(timeout, caller, fmt,
+						      args);
+	else
+		ret = nvgpu_timeout_expired_msg_cpu(timeout, caller, fmt,
+						    args);
+	va_end(args);
+
+	return ret;
+}
+
+/**
+ * nvgpu_timeout_peek_expired - Check the status of a timeout.
+ *
+ * @timeout - The timeout to check.
+ *
+ * Returns true if the timeout is expired, false otherwise. In the case of
+ * retry timers this will not increment the underlying retry count. Also if the
+ * timer has expired no messages will be printed.
+ *
+ * This function honors the pre-Si check as well.
+ */
+bool nvgpu_timeout_peek_expired(struct nvgpu_timeout *timeout)
+{
+	if (nvgpu_timeout_is_pre_silicon(timeout))
+		return false;
+
+	if (timeout->flags & NVGPU_TIMER_RETRY_TIMER)
+		return timeout->retries.attempted >=
+					timeout->retries.max_attempts;
+	else
+		return ktime_after(ktime_get(), ns_to_ktime(timeout->time));
+}
+
+/**
+ * nvgpu_udelay - Delay for some number of microseconds.
+ *
+ * @usecs - Microseconds to wait for.
+ *
+ * Wait for at least @usecs microseconds. This is not guaranteed to be perfectly
+ * accurate. This is normally backed by a busy-loop so this means waits should
+ * be kept short, below 100us. If longer delays are necessary then
+ * nvgpu_msleep() should be preferred.
+ *
+ * Alternatively, on some platforms, nvgpu_usleep_range() is usable. This
+ * function will attempt to not use a busy-loop.
+ */
+void nvgpu_udelay(unsigned int usecs)
+{
+	udelay(usecs);
+}
+
+/**
+ * nvgpu_usleep_range - Sleep for a range of microseconds.
+ *
+ * @min_us - Minimum wait time.
+ * @max_us - Maximum wait time.
+ *
+ * Wait for some number of microseconds between @min_us and @max_us. This,
+ * unlike nvgpu_udelay(), will attempt to sleep for the passed number of
+ * microseconds instead of busy looping. Not all platforms support this,
+ * and in that case this reduces to nvgpu_udelay(min_us).
+ *
+ * Linux note: this is not safe to use in atomic context. If you are in
+ * atomic context you must use nvgpu_udelay().
+ */
+void nvgpu_usleep_range(unsigned int min_us, unsigned int max_us)
+{
+	usleep_range(min_us, max_us);
+}
+
+/**
+ * nvgpu_msleep - Sleep for some milliseconds.
+ *
+ * @msecs - Sleep for at least this many milliseconds.
+ *
+ * Sleep for at least @msecs of milliseconds. For small @msecs (less than 20 ms
+ * or so) the sleep will be significantly longer due to scheduling overhead and
+ * mechanics.
+ */
+void nvgpu_msleep(unsigned int msecs)
+{
+	msleep(msecs);
+}
+
+/**
+ * nvgpu_current_time_ms - Time in milliseconds from a monotonic clock.
+ *
+ * Return a clock in millisecond units. The start time of the clock is
+ * unspecified; the time returned can be compared with older ones to measure
+ * durations. The source clock does not jump when the system clock is adjusted.
+ */
+s64 nvgpu_current_time_ms(void)
+{
+	return ktime_to_ms(ktime_get());
+}
+
+/**
+ * nvgpu_current_time_us - Time in microseconds from a monotonic clock.
+ *
+ * Return a clock in microsecond units. The start time of the clock is
+ * unspecified; the time returned can be compared with older ones to measure
+ * durations. The source clock does not jump when the system clock is adjusted.
+ */
+s64 nvgpu_current_time_us(void)
+{
+	return ktime_to_us(ktime_get());
+}
+
+u64 nvgpu_us_counter(void)
+{
+	return (u64)nvgpu_current_time_us();
+}
+
+/**
+ * nvgpu_current_time_ns - Time in nanoseconds from a monotonic clock.
+ *
+ * Return a clock in nanosecond units. The start time of the clock is
+ * unspecified; the time returned can be compared with older ones to measure
+ * durations. The source clock does not jump when the system clock is adjusted.
+ */
+s64 nvgpu_current_time_ns(void)
+{
+	return ktime_to_ns(ktime_get());
+}
+
+/**
+ * nvgpu_hr_timestamp_us - Time in microseconds from a monotonic clock.
+ *
+ * Return a clock in microsecond units. The start time of the clock is
+ * unspecified; the time returned can be compared with older ones to measure
+ * durations. The source clock does not jump when the system clock is adjusted.
+ */
+u64 nvgpu_hr_timestamp_us(void)
+{
+	return nvgpu_us_counter();
+}
+
+/**
+ * nvgpu_hr_timestamp - Opaque 'high resolution' time stamp.
+ *
+ * Return a "high resolution" time stamp. It does not really matter exactly what
+ * it is, so long as it generally returns unique values and monotonically
+ * increases - wrap around _is_ possible though in a system running for long
+ * enough.
+ *
+ * Note: what high resolution means is system dependent.
+ */
+u64 nvgpu_hr_timestamp(void)
+{
+	return get_cycles();
+}