[PATCH 15/25] cobalt/tick: dovetail: install/uninstall proxy tick device

[Jan Kiszka via Xenomai]

From: Hongzhan Chen <hongzhan.c...@intel.com>

Signed-off-by: Hongzhan Chen <hongzhan.c...@intel.com>
[Philippe: protect xntimer_start with nklock]
Signed-off-by: Philippe Gerum <r...@xenomai.org>
Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
 kernel/cobalt/dovetail/tick.c | 83 ++++++++++++++++++++++++++++++++++-
 1 file changed, 81 insertions(+), 2 deletions(-)

diff --git a/kernel/cobalt/dovetail/tick.c b/kernel/cobalt/dovetail/tick.c
index 01927f7089..fba9f78d00 100644
--- a/kernel/cobalt/dovetail/tick.c
+++ b/kernel/cobalt/dovetail/tick.c
@@ -6,8 +6,87 @@
  */
 
 #include <linux/tick.h>
+#include <linux/clockchips.h>
 #include <cobalt/kernel/intr.h>
 #include <pipeline/tick.h>
+#include <cobalt/kernel/sched.h>
+#include <cobalt/kernel/timer.h>
+
+static DEFINE_PER_CPU(struct clock_proxy_device *, proxy_device);
+
+static int proxy_set_next_ktime(ktime_t expires,
+                               struct clock_event_device *proxy_dev)
+{
+       struct xnsched *sched;
+       ktime_t delta;
+       unsigned long flags;
+       int ret;
+
+       /*
+        * When Negative delta have been observed, we set delta zero.
+        * Or else exntimer_start() will return -ETIMEDOUT and do not
+        * trigger shot
+        */
+       delta = ktime_sub(expires, ktime_get_mono_fast_ns());
+       if (delta < 0)
+               delta = 0;
+
+       xnlock_get_irqsave(&nklock, flags);
+       sched = xnsched_current();
+       ret = xntimer_start(&sched->htimer, delta, XN_INFINITE, XN_RELATIVE);
+       xnlock_put_irqrestore(&nklock, flags);
+
+       return ret ? -ETIME : 0;
+}
+
+void xn_core_tick(struct clock_event_device *dummy) /* hard irqs off */
+{
+       xnintr_core_clock_handler();
+}
+
+static int proxy_set_oneshot_stopped(struct clock_event_device *proxy_dev)
+{
+       struct clock_event_device *real_dev;
+       struct clock_proxy_device *dev;
+       struct xnsched *sched;
+       spl_t s;
+
+       dev = container_of(proxy_dev, struct clock_proxy_device, proxy_device);
+
+       /*
+        * In-band wants to disable the clock hardware on entering a
+        * tickless state, so we have to stop our in-band tick
+        * emulation. Propagate the request for shutting down the
+        * hardware to the real device only if we have no outstanding
+        * OOB timers. CAUTION: the in-band timer is counted when
+        * assessing the RQ_IDLE condition, so we need to stop it
+        * prior to testing the latter.
+        */
+       xnlock_get_irqsave(&nklock, s);
+       sched = xnsched_current();
+       xntimer_stop(&sched->htimer);
+
+       if (sched->lflags & XNIDLE) {
+               real_dev = dev->real_device;
+               real_dev->set_state_oneshot_stopped(real_dev);
+       }
+
+       xnlock_put_irqrestore(&nklock, s);
+
+       return 0;
+}
+
+static void setup_proxy(struct clock_proxy_device *dev)
+{
+       struct clock_event_device *proxy_dev = &dev->proxy_device;
+
+       dev->handle_oob_event = xn_core_tick;
+       proxy_dev->features |= CLOCK_EVT_FEAT_KTIME;
+       proxy_dev->set_next_ktime = proxy_set_next_ktime;
+       if (proxy_dev->set_state_oneshot_stopped)
+               proxy_dev->set_state_oneshot_stopped = 
proxy_set_oneshot_stopped;
+       __this_cpu_write(proxy_device, dev);
+}
 
 int pipeline_install_tick_proxy(void)
 {
@@ -18,7 +97,7 @@ int pipeline_install_tick_proxy(void)
                return ret;
 
        /* Install the proxy tick device */
-       TODO(); ret = 0;
+       ret = tick_install_proxy(setup_proxy, &xnsched_realtime_cpus);
        if (ret)
                goto fail_proxy;
 
@@ -33,7 +112,7 @@ fail_proxy:
 void pipeline_uninstall_tick_proxy(void)
 {
        /* Uninstall the proxy tick device. */
-       TODO();
+       tick_uninstall_proxy(&xnsched_realtime_cpus);
 
        pipeline_free_timer_ipi();
 }
-- 
2.26.2