+++ /dev/null
-/*
- * TimeSync API driver.
- *
- * Copyright 2016 Google Inc.
- * Copyright 2016 Linaro Ltd.
- *
- * Released under the GPLv2 only.
- */
-#include <linux/debugfs.h>
-#include <linux/hrtimer.h>
-#include "greybus.h"
-#include "timesync.h"
-#include "greybus_trace.h"
-
-/*
- * Minimum inter-strobe value of one millisecond is chosen because it
- * just-about fits the common definition of a jiffy.
- *
- * Maximum value OTOH is constrained by the number of bits the SVC can fit
- * into a 16 bit up-counter. The SVC configures the timer in microseconds
- * so the maximum allowable value is 65535 microseconds. We clip that value
- * to 10000 microseconds for the sake of using nice round base 10 numbers
- * and since right-now there's no imaginable use-case requiring anything
- * other than a one millisecond inter-strobe time, let alone something
- * higher than ten milliseconds.
- */
-#define GB_TIMESYNC_STROBE_DELAY_US 1000
-#define GB_TIMESYNC_DEFAULT_OFFSET_US 1000
-
-/* Work queue timers long, short and SVC strobe timeout */
-#define GB_TIMESYNC_DELAYED_WORK_LONG msecs_to_jiffies(10)
-#define GB_TIMESYNC_DELAYED_WORK_SHORT msecs_to_jiffies(1)
-#define GB_TIMESYNC_MAX_WAIT_SVC msecs_to_jiffies(5000)
-#define GB_TIMESYNC_KTIME_UPDATE msecs_to_jiffies(1000)
-#define GB_TIMESYNC_MAX_KTIME_CONVERSION 15
-
-/* Maximum number of times we'll retry a failed synchronous sync */
-#define GB_TIMESYNC_MAX_RETRIES 5
-
-/* Reported nanoseconds/femtoseconds per clock */
-static u64 gb_timesync_ns_per_clock;
-static u64 gb_timesync_fs_per_clock;
-
-/* Maximum difference we will accept converting FrameTime to ktime */
-static u32 gb_timesync_max_ktime_diff;
-
-/* Reported clock rate */
-static unsigned long gb_timesync_clock_rate;
-
-/* Workqueue */
-static void gb_timesync_worker(struct work_struct *work);
-
-/* List of SVCs with one FrameTime per SVC */
-static LIST_HEAD(gb_timesync_svc_list);
-
-/* Synchronize parallel contexts accessing a valid timesync_svc pointer */
-static DEFINE_MUTEX(gb_timesync_svc_list_mutex);
-
-/* Structure to convert from FrameTime to timespec/ktime */
-struct gb_timesync_frame_time_data {
- u64 frame_time;
- struct timespec ts;
-};
-
-struct gb_timesync_svc {
- struct list_head list;
- struct list_head interface_list;
- struct gb_svc *svc;
- struct gb_timesync_host_device *timesync_hd;
-
- spinlock_t spinlock; /* Per SVC spinlock to sync with ISR */
- struct mutex mutex; /* Per SVC mutex for regular synchronization */
-
- struct dentry *frame_time_dentry;
- struct dentry *frame_ktime_dentry;
- struct workqueue_struct *work_queue;
- wait_queue_head_t wait_queue;
- struct delayed_work delayed_work;
- struct timer_list ktime_timer;
-
- /* The current local FrameTime */
- u64 frame_time_offset;
- struct gb_timesync_frame_time_data strobe_data[GB_TIMESYNC_MAX_STROBES];
- struct gb_timesync_frame_time_data ktime_data;
-
- /* The SVC FrameTime and relative AP FrameTime @ last TIMESYNC_PING */
- u64 svc_ping_frame_time;
- u64 ap_ping_frame_time;
-
- /* Transitory settings */
- u32 strobe_mask;
- bool offset_down;
- bool print_ping;
- bool capture_ping;
- int strobe;
-
- /* Current state */
- int state;
-};
-
-struct gb_timesync_host_device {
- struct list_head list;
- struct gb_host_device *hd;
- u64 ping_frame_time;
-};
-
-struct gb_timesync_interface {
- struct list_head list;
- struct gb_interface *interface;
- u64 ping_frame_time;
-};
-
-enum gb_timesync_state {
- GB_TIMESYNC_STATE_INVALID = 0,
- GB_TIMESYNC_STATE_INACTIVE = 1,
- GB_TIMESYNC_STATE_INIT = 2,
- GB_TIMESYNC_STATE_WAIT_SVC = 3,
- GB_TIMESYNC_STATE_AUTHORITATIVE = 4,
- GB_TIMESYNC_STATE_PING = 5,
- GB_TIMESYNC_STATE_ACTIVE = 6,
-};
-
-static void gb_timesync_ktime_timer_fn(unsigned long data);
-
-static u64 gb_timesync_adjust_count(struct gb_timesync_svc *timesync_svc,
- u64 counts)
-{
- if (timesync_svc->offset_down)
- return counts - timesync_svc->frame_time_offset;
- else
- return counts + timesync_svc->frame_time_offset;
-}
-
-/*
- * This function provides the authoritative FrameTime to a calling function. It
- * is designed to be lockless and should remain that way the caller is assumed
- * to be state-aware.
- */
-static u64 __gb_timesync_get_frame_time(struct gb_timesync_svc *timesync_svc)
-{
- u64 clocks = gb_timesync_platform_get_counter();
-
- return gb_timesync_adjust_count(timesync_svc, clocks);
-}
-
-static void gb_timesync_schedule_svc_timeout(struct gb_timesync_svc
- *timesync_svc)
-{
- queue_delayed_work(timesync_svc->work_queue,
- ×ync_svc->delayed_work,
- GB_TIMESYNC_MAX_WAIT_SVC);
-}
-
-static void gb_timesync_set_state(struct gb_timesync_svc *timesync_svc,
- int state)
-{
- switch (state) {
- case GB_TIMESYNC_STATE_INVALID:
- timesync_svc->state = state;
- wake_up(×ync_svc->wait_queue);
- break;
- case GB_TIMESYNC_STATE_INACTIVE:
- timesync_svc->state = state;
- wake_up(×ync_svc->wait_queue);
- break;
- case GB_TIMESYNC_STATE_INIT:
- if (timesync_svc->state != GB_TIMESYNC_STATE_INVALID) {
- timesync_svc->strobe = 0;
- timesync_svc->frame_time_offset = 0;
- timesync_svc->state = state;
- cancel_delayed_work(×ync_svc->delayed_work);
- queue_delayed_work(timesync_svc->work_queue,
- ×ync_svc->delayed_work,
- GB_TIMESYNC_DELAYED_WORK_LONG);
- }
- break;
- case GB_TIMESYNC_STATE_WAIT_SVC:
- if (timesync_svc->state == GB_TIMESYNC_STATE_INIT)
- timesync_svc->state = state;
- break;
- case GB_TIMESYNC_STATE_AUTHORITATIVE:
- if (timesync_svc->state == GB_TIMESYNC_STATE_WAIT_SVC) {
- timesync_svc->state = state;
- cancel_delayed_work(×ync_svc->delayed_work);
- queue_delayed_work(timesync_svc->work_queue,
- ×ync_svc->delayed_work, 0);
- }
- break;
- case GB_TIMESYNC_STATE_PING:
- if (timesync_svc->state == GB_TIMESYNC_STATE_ACTIVE) {
- timesync_svc->state = state;
- queue_delayed_work(timesync_svc->work_queue,
- ×ync_svc->delayed_work,
- GB_TIMESYNC_DELAYED_WORK_SHORT);
- }
- break;
- case GB_TIMESYNC_STATE_ACTIVE:
- if (timesync_svc->state == GB_TIMESYNC_STATE_AUTHORITATIVE ||
- timesync_svc->state == GB_TIMESYNC_STATE_PING) {
- timesync_svc->state = state;
- wake_up(×ync_svc->wait_queue);
- }
- break;
- }
-
- if (WARN_ON(timesync_svc->state != state)) {
- pr_err("Invalid state transition %d=>%d\n",
- timesync_svc->state, state);
- }
-}
-
-static void gb_timesync_set_state_atomic(struct gb_timesync_svc *timesync_svc,
- int state)
-{
- unsigned long flags;
-
- spin_lock_irqsave(×ync_svc->spinlock, flags);
- gb_timesync_set_state(timesync_svc, state);
- spin_unlock_irqrestore(×ync_svc->spinlock, flags);
-}
-
-static u64 gb_timesync_diff(u64 x, u64 y)
-{
- if (x > y)
- return x - y;
- else
- return y - x;
-}
-
-static void gb_timesync_adjust_to_svc(struct gb_timesync_svc *svc,
- u64 svc_frame_time, u64 ap_frame_time)
-{
- if (svc_frame_time > ap_frame_time) {
- svc->frame_time_offset = svc_frame_time - ap_frame_time;
- svc->offset_down = false;
- } else {
- svc->frame_time_offset = ap_frame_time - svc_frame_time;
- svc->offset_down = true;
- }
-}
-
-/*
- * Associate a FrameTime with a ktime timestamp represented as struct timespec
- * Requires the calling context to hold timesync_svc->mutex
- */
-static void gb_timesync_store_ktime(struct gb_timesync_svc *timesync_svc,
- struct timespec ts, u64 frame_time)
-{
- timesync_svc->ktime_data.ts = ts;
- timesync_svc->ktime_data.frame_time = frame_time;
-}
-
-/*
- * Find the two pulses that best-match our expected inter-strobe gap and
- * then calculate the difference between the SVC time at the second pulse
- * to the local time at the second pulse.
- */
-static void gb_timesync_collate_frame_time(struct gb_timesync_svc *timesync_svc,
- u64 *frame_time)
-{
- int i = 0;
- u64 delta, ap_frame_time;
- u64 strobe_delay_ns = GB_TIMESYNC_STROBE_DELAY_US * NSEC_PER_USEC;
- u64 least = 0;
-
- for (i = 1; i < GB_TIMESYNC_MAX_STROBES; i++) {
- delta = timesync_svc->strobe_data[i].frame_time -
- timesync_svc->strobe_data[i - 1].frame_time;
- delta *= gb_timesync_ns_per_clock;
- delta = gb_timesync_diff(delta, strobe_delay_ns);
-
- if (!least || delta < least) {
- least = delta;
- gb_timesync_adjust_to_svc(timesync_svc, frame_time[i],
- timesync_svc->strobe_data[i].frame_time);
-
- ap_frame_time = timesync_svc->strobe_data[i].frame_time;
- ap_frame_time = gb_timesync_adjust_count(timesync_svc,
- ap_frame_time);
- gb_timesync_store_ktime(timesync_svc,
- timesync_svc->strobe_data[i].ts,
- ap_frame_time);
-
- pr_debug("adjust %s local %llu svc %llu delta %llu\n",
- timesync_svc->offset_down ? "down" : "up",
- timesync_svc->strobe_data[i].frame_time,
- frame_time[i], delta);
- }
- }
-}
-
-static void gb_timesync_teardown(struct gb_timesync_svc *timesync_svc)
-{
- struct gb_timesync_interface *timesync_interface;
- struct gb_svc *svc = timesync_svc->svc;
- struct gb_interface *interface;
- struct gb_host_device *hd;
- int ret;
-
- list_for_each_entry(timesync_interface,
- ×ync_svc->interface_list, list) {
- interface = timesync_interface->interface;
- ret = gb_interface_timesync_disable(interface);
- if (ret) {
- dev_err(&interface->dev,
- "interface timesync_disable %d\n", ret);
- }
- }
-
- hd = timesync_svc->timesync_hd->hd;
- ret = hd->driver->timesync_disable(hd);
- if (ret < 0) {
- dev_err(&hd->dev, "host timesync_disable %d\n",
- ret);
- }
-
- gb_svc_timesync_wake_pins_release(svc);
- gb_svc_timesync_disable(svc);
- gb_timesync_platform_unlock_bus();
-
- gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_INACTIVE);
-}
-
-static void gb_timesync_platform_lock_bus_fail(struct gb_timesync_svc
- *timesync_svc, int ret)
-{
- if (ret == -EAGAIN) {
- gb_timesync_set_state(timesync_svc, timesync_svc->state);
- } else {
- pr_err("Failed to lock timesync bus %d\n", ret);
- gb_timesync_set_state(timesync_svc, GB_TIMESYNC_STATE_INACTIVE);
- }
-}
-
-static void gb_timesync_enable(struct gb_timesync_svc *timesync_svc)
-{
- struct gb_svc *svc = timesync_svc->svc;
- struct gb_host_device *hd;
- struct gb_timesync_interface *timesync_interface;
- struct gb_interface *interface;
- u64 init_frame_time;
- unsigned long clock_rate = gb_timesync_clock_rate;
- int ret;
-
- /*
- * Get access to the wake pins in the AP and SVC
- * Release these pins either in gb_timesync_teardown() or in
- * gb_timesync_authoritative()
- */
- ret = gb_timesync_platform_lock_bus(timesync_svc);
- if (ret < 0) {
- gb_timesync_platform_lock_bus_fail(timesync_svc, ret);
- return;
- }
- ret = gb_svc_timesync_wake_pins_acquire(svc, timesync_svc->strobe_mask);
- if (ret) {
- dev_err(&svc->dev,
- "gb_svc_timesync_wake_pins_acquire %d\n", ret);
- gb_timesync_teardown(timesync_svc);
- return;
- }
-
- /* Choose an initial time in the future */
- init_frame_time = __gb_timesync_get_frame_time(timesync_svc) + 100000UL;
-
- /* Send enable command to all relevant participants */
- list_for_each_entry(timesync_interface, ×ync_svc->interface_list,
- list) {
- interface = timesync_interface->interface;
- ret = gb_interface_timesync_enable(interface,
- GB_TIMESYNC_MAX_STROBES,
- init_frame_time,
- GB_TIMESYNC_STROBE_DELAY_US,
- clock_rate);
- if (ret) {
- dev_err(&interface->dev,
- "interface timesync_enable %d\n", ret);
- }
- }
-
- hd = timesync_svc->timesync_hd->hd;
- ret = hd->driver->timesync_enable(hd, GB_TIMESYNC_MAX_STROBES,
- init_frame_time,
- GB_TIMESYNC_STROBE_DELAY_US,
- clock_rate);
- if (ret < 0) {
- dev_err(&hd->dev, "host timesync_enable %d\n",
- ret);
- }
-
- gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_WAIT_SVC);
- ret = gb_svc_timesync_enable(svc, GB_TIMESYNC_MAX_STROBES,
- init_frame_time,
- GB_TIMESYNC_STROBE_DELAY_US,
- clock_rate);
- if (ret) {
- dev_err(&svc->dev,
- "gb_svc_timesync_enable %d\n", ret);
- gb_timesync_teardown(timesync_svc);
- return;
- }
-
- /* Schedule a timeout waiting for SVC to complete strobing */
- gb_timesync_schedule_svc_timeout(timesync_svc);
-}
-
-static void gb_timesync_authoritative(struct gb_timesync_svc *timesync_svc)
-{
- struct gb_svc *svc = timesync_svc->svc;
- struct gb_host_device *hd;
- struct gb_timesync_interface *timesync_interface;
- struct gb_interface *interface;
- u64 svc_frame_time[GB_TIMESYNC_MAX_STROBES];
- int ret;
-
- /* Get authoritative time from SVC and adjust local clock */
- ret = gb_svc_timesync_authoritative(svc, svc_frame_time);
- if (ret) {
- dev_err(&svc->dev,
- "gb_svc_timesync_authoritative %d\n", ret);
- gb_timesync_teardown(timesync_svc);
- return;
- }
- gb_timesync_collate_frame_time(timesync_svc, svc_frame_time);
-
- /* Transmit authoritative time to downstream slaves */
- hd = timesync_svc->timesync_hd->hd;
- ret = hd->driver->timesync_authoritative(hd, svc_frame_time);
- if (ret < 0)
- dev_err(&hd->dev, "host timesync_authoritative %d\n", ret);
-
- list_for_each_entry(timesync_interface,
- ×ync_svc->interface_list, list) {
- interface = timesync_interface->interface;
- ret = gb_interface_timesync_authoritative(
- interface,
- svc_frame_time);
- if (ret) {
- dev_err(&interface->dev,
- "interface timesync_authoritative %d\n", ret);
- }
- }
-
- /* Release wake pins */
- gb_svc_timesync_wake_pins_release(svc);
- gb_timesync_platform_unlock_bus();
-
- /* Transition to state ACTIVE */
- gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_ACTIVE);
-
- /* Schedule a ping to verify the synchronized system time */
- timesync_svc->print_ping = true;
- gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_PING);
-}
-
-static int __gb_timesync_get_status(struct gb_timesync_svc *timesync_svc)
-{
- int ret = -EINVAL;
-
- switch (timesync_svc->state) {
- case GB_TIMESYNC_STATE_INVALID:
- case GB_TIMESYNC_STATE_INACTIVE:
- ret = -ENODEV;
- break;
- case GB_TIMESYNC_STATE_INIT:
- case GB_TIMESYNC_STATE_WAIT_SVC:
- case GB_TIMESYNC_STATE_AUTHORITATIVE:
- ret = -EAGAIN;
- break;
- case GB_TIMESYNC_STATE_PING:
- case GB_TIMESYNC_STATE_ACTIVE:
- ret = 0;
- break;
- }
- return ret;
-}
-
-/*
- * This routine takes a FrameTime and derives the difference with-respect
- * to a reference FrameTime/ktime pair. It then returns the calculated
- * ktime based on the difference between the supplied FrameTime and
- * the reference FrameTime.
- *
- * The time difference is calculated to six decimal places. Taking 19.2MHz
- * as an example this means we have 52.083333~ nanoseconds per clock or
- * 52083333~ femtoseconds per clock.
- *
- * Naively taking the count difference and converting to
- * seconds/nanoseconds would quickly see the 0.0833 component produce
- * noticeable errors. For example a time difference of one second would
- * loose 19200000 * 0.08333x nanoseconds or 1.59 seconds.
- *
- * In contrast calculating in femtoseconds the same example of 19200000 *
- * 0.000000083333x nanoseconds per count of error is just 1.59 nanoseconds!
- *
- * Continuing the example of 19.2 MHz we cap the maximum error difference
- * at a worst-case 0.3 microseconds over a potential calculation window of
- * abount 15 seconds, meaning you can convert a FrameTime that is <= 15
- * seconds older/younger than the reference time with a maximum error of
- * 0.2385 useconds. Note 19.2MHz is an example frequency not a requirement.
- */
-static int gb_timesync_to_timespec(struct gb_timesync_svc *timesync_svc,
- u64 frame_time, struct timespec *ts)
-{
- unsigned long flags;
- u64 delta_fs, counts, sec, nsec;
- bool add;
- int ret = 0;
-
- memset(ts, 0x00, sizeof(*ts));
- mutex_lock(×ync_svc->mutex);
- spin_lock_irqsave(×ync_svc->spinlock, flags);
-
- ret = __gb_timesync_get_status(timesync_svc);
- if (ret)
- goto done;
-
- /* Support calculating ktime upwards or downwards from the reference */
- if (frame_time < timesync_svc->ktime_data.frame_time) {
- add = false;
- counts = timesync_svc->ktime_data.frame_time - frame_time;
- } else {
- add = true;
- counts = frame_time - timesync_svc->ktime_data.frame_time;
- }
-
- /* Enforce the .23 of a usecond boundary @ 19.2MHz */
- if (counts > gb_timesync_max_ktime_diff) {
- ret = -EINVAL;
- goto done;
- }
-
- /* Determine the time difference in femtoseconds */
- delta_fs = counts * gb_timesync_fs_per_clock;
-
- /* Convert to seconds */
- sec = delta_fs;
- do_div(sec, NSEC_PER_SEC);
- do_div(sec, 1000000UL);
-
- /* Get the nanosecond remainder */
- nsec = do_div(delta_fs, sec);
- do_div(nsec, 1000000UL);
-
- if (add) {
- /* Add the calculated offset - overflow nanoseconds upwards */
- ts->tv_sec = timesync_svc->ktime_data.ts.tv_sec + sec;
- ts->tv_nsec = timesync_svc->ktime_data.ts.tv_nsec + nsec;
- if (ts->tv_nsec >= NSEC_PER_SEC) {
- ts->tv_sec++;
- ts->tv_nsec -= NSEC_PER_SEC;
- }
- } else {
- /* Subtract the difference over/underflow as necessary */
- if (nsec > timesync_svc->ktime_data.ts.tv_nsec) {
- sec++;
- nsec = nsec + timesync_svc->ktime_data.ts.tv_nsec;
- nsec = do_div(nsec, NSEC_PER_SEC);
- } else {
- nsec = timesync_svc->ktime_data.ts.tv_nsec - nsec;
- }
- /* Cannot return a negative second value */
- if (sec > timesync_svc->ktime_data.ts.tv_sec) {
- ret = -EINVAL;
- goto done;
- }
- ts->tv_sec = timesync_svc->ktime_data.ts.tv_sec - sec;
- ts->tv_nsec = nsec;
- }
-done:
- spin_unlock_irqrestore(×ync_svc->spinlock, flags);
- mutex_unlock(×ync_svc->mutex);
- return ret;
-}
-
-static size_t gb_timesync_log_frame_time(struct gb_timesync_svc *timesync_svc,
- char *buf, size_t buflen)
-{
- struct gb_svc *svc = timesync_svc->svc;
- struct gb_host_device *hd;
- struct gb_timesync_interface *timesync_interface;
- struct gb_interface *interface;
- unsigned int len;
- size_t off;
-
- /* AP/SVC */
- off = snprintf(buf, buflen, "%s frametime: ap=%llu %s=%llu ",
- greybus_bus_type.name,
- timesync_svc->ap_ping_frame_time, dev_name(&svc->dev),
- timesync_svc->svc_ping_frame_time);
- len = buflen - off;
-
- /* APB/GPB */
- if (len < buflen) {
- hd = timesync_svc->timesync_hd->hd;
- off += snprintf(&buf[off], len, "%s=%llu ", dev_name(&hd->dev),
- timesync_svc->timesync_hd->ping_frame_time);
- len = buflen - off;
- }
-
- list_for_each_entry(timesync_interface,
- ×ync_svc->interface_list, list) {
- if (len < buflen) {
- interface = timesync_interface->interface;
- off += snprintf(&buf[off], len, "%s=%llu ",
- dev_name(&interface->dev),
- timesync_interface->ping_frame_time);
- len = buflen - off;
- }
- }
- if (len < buflen)
- off += snprintf(&buf[off], len, "\n");
- return off;
-}
-
-static size_t gb_timesync_log_frame_ktime(struct gb_timesync_svc *timesync_svc,
- char *buf, size_t buflen)
-{
- struct gb_svc *svc = timesync_svc->svc;
- struct gb_host_device *hd;
- struct gb_timesync_interface *timesync_interface;
- struct gb_interface *interface;
- struct timespec ts;
- unsigned int len;
- size_t off;
-
- /* AP */
- gb_timesync_to_timespec(timesync_svc, timesync_svc->ap_ping_frame_time,
- &ts);
- off = snprintf(buf, buflen, "%s frametime: ap=%lu.%lu ",
- greybus_bus_type.name, ts.tv_sec, ts.tv_nsec);
- len = buflen - off;
- if (len >= buflen)
- goto done;
-
- /* SVC */
- gb_timesync_to_timespec(timesync_svc, timesync_svc->svc_ping_frame_time,
- &ts);
- off += snprintf(&buf[off], len, "%s=%lu.%lu ", dev_name(&svc->dev),
- ts.tv_sec, ts.tv_nsec);
- len = buflen - off;
- if (len >= buflen)
- goto done;
-
- /* APB/GPB */
- hd = timesync_svc->timesync_hd->hd;
- gb_timesync_to_timespec(timesync_svc,
- timesync_svc->timesync_hd->ping_frame_time,
- &ts);
- off += snprintf(&buf[off], len, "%s=%lu.%lu ",
- dev_name(&hd->dev),
- ts.tv_sec, ts.tv_nsec);
- len = buflen - off;
- if (len >= buflen)
- goto done;
-
- list_for_each_entry(timesync_interface,
- ×ync_svc->interface_list, list) {
- interface = timesync_interface->interface;
- gb_timesync_to_timespec(timesync_svc,
- timesync_interface->ping_frame_time,
- &ts);
- off += snprintf(&buf[off], len, "%s=%lu.%lu ",
- dev_name(&interface->dev),
- ts.tv_sec, ts.tv_nsec);
- len = buflen - off;
- if (len >= buflen)
- goto done;
- }
- off += snprintf(&buf[off], len, "\n");
-done:
- return off;
-}
-
-/*
- * Send an SVC initiated wake 'ping' to each TimeSync participant.
- * Get the FrameTime from each participant associated with the wake
- * ping.
- */
-static void gb_timesync_ping(struct gb_timesync_svc *timesync_svc)
-{
- struct gb_svc *svc = timesync_svc->svc;
- struct gb_host_device *hd;
- struct gb_timesync_interface *timesync_interface;
- struct gb_control *control;
- u64 *ping_frame_time;
- int ret;
-
- /* Get access to the wake pins in the AP and SVC */
- ret = gb_timesync_platform_lock_bus(timesync_svc);
- if (ret < 0) {
- gb_timesync_platform_lock_bus_fail(timesync_svc, ret);
- return;
- }
- ret = gb_svc_timesync_wake_pins_acquire(svc, timesync_svc->strobe_mask);
- if (ret) {
- dev_err(&svc->dev,
- "gb_svc_timesync_wake_pins_acquire %d\n", ret);
- gb_timesync_teardown(timesync_svc);
- return;
- }
-
- /* Have SVC generate a timesync ping */
- timesync_svc->capture_ping = true;
- timesync_svc->svc_ping_frame_time = 0;
- ret = gb_svc_timesync_ping(svc, ×ync_svc->svc_ping_frame_time);
- timesync_svc->capture_ping = false;
- if (ret) {
- dev_err(&svc->dev,
- "gb_svc_timesync_ping %d\n", ret);
- gb_timesync_teardown(timesync_svc);
- return;
- }
-
- /* Get the ping FrameTime from each APB/GPB */
- hd = timesync_svc->timesync_hd->hd;
- timesync_svc->timesync_hd->ping_frame_time = 0;
- ret = hd->driver->timesync_get_last_event(hd,
- ×ync_svc->timesync_hd->ping_frame_time);
- if (ret)
- dev_err(&hd->dev, "host timesync_get_last_event %d\n", ret);
-
- list_for_each_entry(timesync_interface,
- ×ync_svc->interface_list, list) {
- control = timesync_interface->interface->control;
- timesync_interface->ping_frame_time = 0;
- ping_frame_time = ×ync_interface->ping_frame_time;
- ret = gb_control_timesync_get_last_event(control,
- ping_frame_time);
- if (ret) {
- dev_err(×ync_interface->interface->dev,
- "gb_control_timesync_get_last_event %d\n", ret);
- }
- }
-
- /* Ping success - move to timesync active */
- gb_svc_timesync_wake_pins_release(svc);
- gb_timesync_platform_unlock_bus();
- gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_ACTIVE);
-}
-
-static void gb_timesync_log_ping_time(struct gb_timesync_svc *timesync_svc)
-{
- char *buf;
-
- if (!timesync_svc->print_ping)
- return;
-
- buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
- if (buf) {
- gb_timesync_log_frame_time(timesync_svc, buf, PAGE_SIZE);
- dev_dbg(×ync_svc->svc->dev, "%s", buf);
- kfree(buf);
- }
-}
-
-/*
- * Perform the actual work of scheduled TimeSync logic.
- */
-static void gb_timesync_worker(struct work_struct *work)
-{
- struct delayed_work *delayed_work = to_delayed_work(work);
- struct gb_timesync_svc *timesync_svc =
- container_of(delayed_work, struct gb_timesync_svc, delayed_work);
-
- mutex_lock(×ync_svc->mutex);
-
- switch (timesync_svc->state) {
- case GB_TIMESYNC_STATE_INIT:
- gb_timesync_enable(timesync_svc);
- break;
-
- case GB_TIMESYNC_STATE_WAIT_SVC:
- dev_err(×ync_svc->svc->dev,
- "timeout SVC strobe completion %d/%d\n",
- timesync_svc->strobe, GB_TIMESYNC_MAX_STROBES);
- gb_timesync_teardown(timesync_svc);
- break;
-
- case GB_TIMESYNC_STATE_AUTHORITATIVE:
- gb_timesync_authoritative(timesync_svc);
- break;
-
- case GB_TIMESYNC_STATE_PING:
- gb_timesync_ping(timesync_svc);
- gb_timesync_log_ping_time(timesync_svc);
- break;
-
- default:
- pr_err("Invalid state %d for delayed work\n",
- timesync_svc->state);
- break;
- }
-
- mutex_unlock(×ync_svc->mutex);
-}
-
-/*
- * Schedule a new TimeSync INIT or PING operation serialized w/r to
- * gb_timesync_worker().
- */
-static int gb_timesync_schedule(struct gb_timesync_svc *timesync_svc, int state)
-{
- int ret = 0;
-
- if (state != GB_TIMESYNC_STATE_INIT && state != GB_TIMESYNC_STATE_PING)
- return -EINVAL;
-
- mutex_lock(×ync_svc->mutex);
- if (timesync_svc->state != GB_TIMESYNC_STATE_INVALID)
- gb_timesync_set_state_atomic(timesync_svc, state);
- else
- ret = -ENODEV;
-
- mutex_unlock(×ync_svc->mutex);
- return ret;
-}
-
-static int __gb_timesync_schedule_synchronous(
- struct gb_timesync_svc *timesync_svc, int state)
-{
- unsigned long flags;
- int ret;
-
- ret = gb_timesync_schedule(timesync_svc, state);
- if (ret)
- return ret;
-
- ret = wait_event_interruptible(timesync_svc->wait_queue,
- (timesync_svc->state == GB_TIMESYNC_STATE_ACTIVE ||
- timesync_svc->state == GB_TIMESYNC_STATE_INACTIVE ||
- timesync_svc->state == GB_TIMESYNC_STATE_INVALID));
- if (ret)
- return ret;
-
- mutex_lock(×ync_svc->mutex);
- spin_lock_irqsave(×ync_svc->spinlock, flags);
-
- ret = __gb_timesync_get_status(timesync_svc);
-
- spin_unlock_irqrestore(×ync_svc->spinlock, flags);
- mutex_unlock(×ync_svc->mutex);
-
- return ret;
-}
-
-static struct gb_timesync_svc *gb_timesync_find_timesync_svc(
- struct gb_host_device *hd)
-{
- struct gb_timesync_svc *timesync_svc;
-
- list_for_each_entry(timesync_svc, &gb_timesync_svc_list, list) {
- if (timesync_svc->svc == hd->svc)
- return timesync_svc;
- }
- return NULL;
-}
-
-static struct gb_timesync_interface *gb_timesync_find_timesync_interface(
- struct gb_timesync_svc *timesync_svc,
- struct gb_interface *interface)
-{
- struct gb_timesync_interface *timesync_interface;
-
- list_for_each_entry(timesync_interface, ×ync_svc->interface_list, list) {
- if (timesync_interface->interface == interface)
- return timesync_interface;
- }
- return NULL;
-}
-
-int gb_timesync_schedule_synchronous(struct gb_interface *interface)
-{
- int ret;
- struct gb_timesync_svc *timesync_svc;
- int retries;
-
- if (!(interface->features & GREYBUS_INTERFACE_FEATURE_TIMESYNC))
- return 0;
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- for (retries = 0; retries < GB_TIMESYNC_MAX_RETRIES; retries++) {
- timesync_svc = gb_timesync_find_timesync_svc(interface->hd);
- if (!timesync_svc) {
- ret = -ENODEV;
- goto done;
- }
-
- ret = __gb_timesync_schedule_synchronous(timesync_svc,
- GB_TIMESYNC_STATE_INIT);
- if (!ret)
- break;
- }
- if (ret && retries == GB_TIMESYNC_MAX_RETRIES)
- ret = -ETIMEDOUT;
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(gb_timesync_schedule_synchronous);
-
-void gb_timesync_schedule_asynchronous(struct gb_interface *interface)
-{
- struct gb_timesync_svc *timesync_svc;
-
- if (!(interface->features & GREYBUS_INTERFACE_FEATURE_TIMESYNC))
- return;
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- timesync_svc = gb_timesync_find_timesync_svc(interface->hd);
- if (!timesync_svc)
- goto done;
-
- gb_timesync_schedule(timesync_svc, GB_TIMESYNC_STATE_INIT);
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
- return;
-}
-EXPORT_SYMBOL_GPL(gb_timesync_schedule_asynchronous);
-
-static ssize_t gb_timesync_ping_read(struct file *file, char __user *ubuf,
- size_t len, loff_t *offset, bool ktime)
-{
- struct gb_timesync_svc *timesync_svc = file_inode(file)->i_private;
- char *buf;
- ssize_t ret = 0;
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- mutex_lock(×ync_svc->mutex);
- if (list_empty(×ync_svc->interface_list))
- ret = -ENODEV;
- timesync_svc->print_ping = false;
- mutex_unlock(×ync_svc->mutex);
- if (ret)
- goto done;
-
- ret = __gb_timesync_schedule_synchronous(timesync_svc,
- GB_TIMESYNC_STATE_PING);
- if (ret)
- goto done;
-
- buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
- if (!buf) {
- ret = -ENOMEM;
- goto done;
- }
-
- if (ktime)
- ret = gb_timesync_log_frame_ktime(timesync_svc, buf, PAGE_SIZE);
- else
- ret = gb_timesync_log_frame_time(timesync_svc, buf, PAGE_SIZE);
- if (ret > 0)
- ret = simple_read_from_buffer(ubuf, len, offset, buf, ret);
- kfree(buf);
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
- return ret;
-}
-
-static ssize_t gb_timesync_ping_read_frame_time(struct file *file,
- char __user *buf,
- size_t len, loff_t *offset)
-{
- return gb_timesync_ping_read(file, buf, len, offset, false);
-}
-
-static ssize_t gb_timesync_ping_read_frame_ktime(struct file *file,
- char __user *buf,
- size_t len, loff_t *offset)
-{
- return gb_timesync_ping_read(file, buf, len, offset, true);
-}
-
-static const struct file_operations gb_timesync_debugfs_frame_time_ops = {
- .read = gb_timesync_ping_read_frame_time,
-};
-
-static const struct file_operations gb_timesync_debugfs_frame_ktime_ops = {
- .read = gb_timesync_ping_read_frame_ktime,
-};
-
-static int gb_timesync_hd_add(struct gb_timesync_svc *timesync_svc,
- struct gb_host_device *hd)
-{
- struct gb_timesync_host_device *timesync_hd;
-
- timesync_hd = kzalloc(sizeof(*timesync_hd), GFP_KERNEL);
- if (!timesync_hd)
- return -ENOMEM;
-
- WARN_ON(timesync_svc->timesync_hd);
- timesync_hd->hd = hd;
- timesync_svc->timesync_hd = timesync_hd;
-
- return 0;
-}
-
-static void gb_timesync_hd_remove(struct gb_timesync_svc *timesync_svc,
- struct gb_host_device *hd)
-{
- if (timesync_svc->timesync_hd->hd == hd) {
- kfree(timesync_svc->timesync_hd);
- timesync_svc->timesync_hd = NULL;
- return;
- }
- WARN_ON(1);
-}
-
-int gb_timesync_svc_add(struct gb_svc *svc)
-{
- struct gb_timesync_svc *timesync_svc;
- int ret;
-
- timesync_svc = kzalloc(sizeof(*timesync_svc), GFP_KERNEL);
- if (!timesync_svc)
- return -ENOMEM;
-
- timesync_svc->work_queue =
- create_singlethread_workqueue("gb-timesync-work_queue");
-
- if (!timesync_svc->work_queue) {
- kfree(timesync_svc);
- return -ENOMEM;
- }
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- INIT_LIST_HEAD(×ync_svc->interface_list);
- INIT_DELAYED_WORK(×ync_svc->delayed_work, gb_timesync_worker);
- mutex_init(×ync_svc->mutex);
- spin_lock_init(×ync_svc->spinlock);
- init_waitqueue_head(×ync_svc->wait_queue);
-
- timesync_svc->svc = svc;
- timesync_svc->frame_time_offset = 0;
- timesync_svc->capture_ping = false;
- gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_INACTIVE);
-
- timesync_svc->frame_time_dentry =
- debugfs_create_file("frame-time", S_IRUGO, svc->debugfs_dentry,
- timesync_svc,
- &gb_timesync_debugfs_frame_time_ops);
- timesync_svc->frame_ktime_dentry =
- debugfs_create_file("frame-ktime", S_IRUGO, svc->debugfs_dentry,
- timesync_svc,
- &gb_timesync_debugfs_frame_ktime_ops);
-
- list_add(×ync_svc->list, &gb_timesync_svc_list);
- ret = gb_timesync_hd_add(timesync_svc, svc->hd);
- if (ret) {
- list_del(×ync_svc->list);
- debugfs_remove(timesync_svc->frame_ktime_dentry);
- debugfs_remove(timesync_svc->frame_time_dentry);
- destroy_workqueue(timesync_svc->work_queue);
- kfree(timesync_svc);
- goto done;
- }
-
- init_timer(×ync_svc->ktime_timer);
- timesync_svc->ktime_timer.function = gb_timesync_ktime_timer_fn;
- timesync_svc->ktime_timer.expires = jiffies + GB_TIMESYNC_KTIME_UPDATE;
- timesync_svc->ktime_timer.data = (unsigned long)timesync_svc;
- add_timer(×ync_svc->ktime_timer);
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(gb_timesync_svc_add);
-
-void gb_timesync_svc_remove(struct gb_svc *svc)
-{
- struct gb_timesync_svc *timesync_svc;
- struct gb_timesync_interface *timesync_interface;
- struct gb_timesync_interface *next;
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- timesync_svc = gb_timesync_find_timesync_svc(svc->hd);
- if (!timesync_svc)
- goto done;
-
- cancel_delayed_work_sync(×ync_svc->delayed_work);
-
- mutex_lock(×ync_svc->mutex);
-
- gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_INVALID);
- del_timer_sync(×ync_svc->ktime_timer);
- gb_timesync_teardown(timesync_svc);
-
- gb_timesync_hd_remove(timesync_svc, svc->hd);
- list_for_each_entry_safe(timesync_interface, next,
- ×ync_svc->interface_list, list) {
- list_del(×ync_interface->list);
- kfree(timesync_interface);
- }
- debugfs_remove(timesync_svc->frame_ktime_dentry);
- debugfs_remove(timesync_svc->frame_time_dentry);
- destroy_workqueue(timesync_svc->work_queue);
- list_del(×ync_svc->list);
-
- mutex_unlock(×ync_svc->mutex);
-
- kfree(timesync_svc);
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
-}
-EXPORT_SYMBOL_GPL(gb_timesync_svc_remove);
-
-/*
- * Add a Greybus Interface to the set of TimeSync Interfaces.
- */
-int gb_timesync_interface_add(struct gb_interface *interface)
-{
- struct gb_timesync_svc *timesync_svc;
- struct gb_timesync_interface *timesync_interface;
- int ret = 0;
-
- if (!(interface->features & GREYBUS_INTERFACE_FEATURE_TIMESYNC))
- return 0;
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- timesync_svc = gb_timesync_find_timesync_svc(interface->hd);
- if (!timesync_svc) {
- ret = -ENODEV;
- goto done;
- }
-
- timesync_interface = kzalloc(sizeof(*timesync_interface), GFP_KERNEL);
- if (!timesync_interface) {
- ret = -ENOMEM;
- goto done;
- }
-
- mutex_lock(×ync_svc->mutex);
- timesync_interface->interface = interface;
- list_add(×ync_interface->list, ×ync_svc->interface_list);
- timesync_svc->strobe_mask |= 1 << interface->interface_id;
- mutex_unlock(×ync_svc->mutex);
-
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(gb_timesync_interface_add);
-
-/*
- * Remove a Greybus Interface from the set of TimeSync Interfaces.
- */
-void gb_timesync_interface_remove(struct gb_interface *interface)
-{
- struct gb_timesync_svc *timesync_svc;
- struct gb_timesync_interface *timesync_interface;
-
- if (!(interface->features & GREYBUS_INTERFACE_FEATURE_TIMESYNC))
- return;
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- timesync_svc = gb_timesync_find_timesync_svc(interface->hd);
- if (!timesync_svc)
- goto done;
-
- timesync_interface = gb_timesync_find_timesync_interface(timesync_svc,
- interface);
- if (!timesync_interface)
- goto done;
-
- mutex_lock(×ync_svc->mutex);
- timesync_svc->strobe_mask &= ~(1 << interface->interface_id);
- list_del(×ync_interface->list);
- kfree(timesync_interface);
- mutex_unlock(×ync_svc->mutex);
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
-}
-EXPORT_SYMBOL_GPL(gb_timesync_interface_remove);
-
-/*
- * Give the authoritative FrameTime to the calling function. Returns zero if we
- * are not in GB_TIMESYNC_STATE_ACTIVE.
- */
-static u64 gb_timesync_get_frame_time(struct gb_timesync_svc *timesync_svc)
-{
- unsigned long flags;
- u64 ret;
-
- spin_lock_irqsave(×ync_svc->spinlock, flags);
- if (timesync_svc->state == GB_TIMESYNC_STATE_ACTIVE)
- ret = __gb_timesync_get_frame_time(timesync_svc);
- else
- ret = 0;
- spin_unlock_irqrestore(×ync_svc->spinlock, flags);
- return ret;
-}
-
-u64 gb_timesync_get_frame_time_by_interface(struct gb_interface *interface)
-{
- struct gb_timesync_svc *timesync_svc;
- u64 ret = 0;
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- timesync_svc = gb_timesync_find_timesync_svc(interface->hd);
- if (!timesync_svc)
- goto done;
-
- ret = gb_timesync_get_frame_time(timesync_svc);
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(gb_timesync_get_frame_time_by_interface);
-
-u64 gb_timesync_get_frame_time_by_svc(struct gb_svc *svc)
-{
- struct gb_timesync_svc *timesync_svc;
- u64 ret = 0;
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- timesync_svc = gb_timesync_find_timesync_svc(svc->hd);
- if (!timesync_svc)
- goto done;
-
- ret = gb_timesync_get_frame_time(timesync_svc);
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(gb_timesync_get_frame_time_by_svc);
-
-/* Incrementally updates the conversion base from FrameTime to ktime */
-static void gb_timesync_ktime_timer_fn(unsigned long data)
-{
- struct gb_timesync_svc *timesync_svc =
- (struct gb_timesync_svc *)data;
- unsigned long flags;
- u64 frame_time;
- struct timespec ts;
-
- spin_lock_irqsave(×ync_svc->spinlock, flags);
-
- if (timesync_svc->state != GB_TIMESYNC_STATE_ACTIVE)
- goto done;
-
- ktime_get_ts(&ts);
- frame_time = __gb_timesync_get_frame_time(timesync_svc);
- gb_timesync_store_ktime(timesync_svc, ts, frame_time);
-
-done:
- spin_unlock_irqrestore(×ync_svc->spinlock, flags);
- mod_timer(×ync_svc->ktime_timer,
- jiffies + GB_TIMESYNC_KTIME_UPDATE);
-}
-
-int gb_timesync_to_timespec_by_svc(struct gb_svc *svc, u64 frame_time,
- struct timespec *ts)
-{
- struct gb_timesync_svc *timesync_svc;
- int ret = 0;
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- timesync_svc = gb_timesync_find_timesync_svc(svc->hd);
- if (!timesync_svc) {
- ret = -ENODEV;
- goto done;
- }
- ret = gb_timesync_to_timespec(timesync_svc, frame_time, ts);
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(gb_timesync_to_timespec_by_svc);
-
-int gb_timesync_to_timespec_by_interface(struct gb_interface *interface,
- u64 frame_time, struct timespec *ts)
-{
- struct gb_timesync_svc *timesync_svc;
- int ret = 0;
-
- mutex_lock(&gb_timesync_svc_list_mutex);
- timesync_svc = gb_timesync_find_timesync_svc(interface->hd);
- if (!timesync_svc) {
- ret = -ENODEV;
- goto done;
- }
-
- ret = gb_timesync_to_timespec(timesync_svc, frame_time, ts);
-done:
- mutex_unlock(&gb_timesync_svc_list_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(gb_timesync_to_timespec_by_interface);
-
-void gb_timesync_irq(struct gb_timesync_svc *timesync_svc)
-{
- unsigned long flags;
- u64 strobe_time;
- bool strobe_is_ping = true;
- struct timespec ts;
-
- ktime_get_ts(&ts);
- strobe_time = __gb_timesync_get_frame_time(timesync_svc);
-
- spin_lock_irqsave(×ync_svc->spinlock, flags);
-
- if (timesync_svc->state == GB_TIMESYNC_STATE_PING) {
- if (!timesync_svc->capture_ping)
- goto done_nolog;
- timesync_svc->ap_ping_frame_time = strobe_time;
- goto done_log;
- } else if (timesync_svc->state != GB_TIMESYNC_STATE_WAIT_SVC) {
- goto done_nolog;
- }
-
- timesync_svc->strobe_data[timesync_svc->strobe].frame_time = strobe_time;
- timesync_svc->strobe_data[timesync_svc->strobe].ts = ts;
-
- if (++timesync_svc->strobe == GB_TIMESYNC_MAX_STROBES) {
- gb_timesync_set_state(timesync_svc,
- GB_TIMESYNC_STATE_AUTHORITATIVE);
- }
- strobe_is_ping = false;
-done_log:
- trace_gb_timesync_irq(strobe_is_ping, timesync_svc->strobe,
- GB_TIMESYNC_MAX_STROBES, strobe_time);
-done_nolog:
- spin_unlock_irqrestore(×ync_svc->spinlock, flags);
-}
-EXPORT_SYMBOL(gb_timesync_irq);
-
-int __init gb_timesync_init(void)
-{
- int ret = 0;
-
- ret = gb_timesync_platform_init();
- if (ret) {
- pr_err("timesync platform init fail!\n");
- return ret;
- }
-
- gb_timesync_clock_rate = gb_timesync_platform_get_clock_rate();
-
- /* Calculate nanoseconds and femtoseconds per clock */
- gb_timesync_fs_per_clock = FSEC_PER_SEC;
- do_div(gb_timesync_fs_per_clock, gb_timesync_clock_rate);
- gb_timesync_ns_per_clock = NSEC_PER_SEC;
- do_div(gb_timesync_ns_per_clock, gb_timesync_clock_rate);
-
- /* Calculate the maximum number of clocks we will convert to ktime */
- gb_timesync_max_ktime_diff =
- GB_TIMESYNC_MAX_KTIME_CONVERSION * gb_timesync_clock_rate;
-
- pr_info("Time-Sync @ %lu Hz max ktime conversion +/- %d seconds\n",
- gb_timesync_clock_rate, GB_TIMESYNC_MAX_KTIME_CONVERSION);
- return 0;
-}
-
-void gb_timesync_exit(void)
-{
- gb_timesync_platform_exit();
-}
projects / mirror_ubuntu-artful-kernel.git / commitdiff