cobalt/syscall: dovetail: do not expose clock frequency to user

We don't need this with Dovetail, there is no timestamp arithmetics to
perform in userland whatsoever: we get timestamps from the regular
vDSO-based clock_gettime() call.

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

include/cobalt/kernel/dovetail/pipeline/pipeline.h

@@ -7,6 +7,7 @@
 
 #include <linux/irq_pipeline.h>
 #include <cobalt/kernel/assert.h>
+#include <asm/xenomai/features.h>
 
 typedef unsigned long spl_t;
 
@@ -102,4 +103,9 @@ static inline void pipeline_prepare_panic(void)
 	/* N/A */
 }
 
+static inline void pipeline_collect_features(struct cobalt_featinfo *f)
+{
+	f->clock_freq = 0;	/* N/A */
+}
+
 #endif /* !_COBALT_KERNEL_DOVETAIL_PIPELINE_H */

include/cobalt/kernel/ipipe/pipeline/pipeline.h

@@ -10,6 +10,7 @@
 #endif
 
 #include <pipeline/machine.h>
+#include <asm/xenomai/features.h>
 
 #define xnsched_realtime_domain  cobalt_pipeline.domain
 
@@ -75,4 +76,9 @@ static inline void pipeline_prepare_panic(void)
 	ipipe_prepare_panic();
 }
 
+static inline void pipeline_collect_features(struct cobalt_featinfo *f)
+{
+	f->clock_freq = cobalt_pipeline.clock_freq;
+}
+
 #endif /* !_COBALT_KERNEL_IPIPE_PIPELINE_H */

kernel/cobalt/posix/syscall.c

@@ -332,7 +332,7 @@ static COBALT_SYSCALL(bind, lostage,
 	f->feat_abirev = XENOMAI_ABI_REV;
 	collect_arch_features(f);
 
-	f->clock_freq = cobalt_pipeline.clock_freq;
+	pipeline_collect_features(f);
 	f->vdso_offset = cobalt_umm_offset(&cobalt_ppd_get(1)->umm, nkvdso);
 
 	if (cobalt_copy_to_user(u_breq, &breq, sizeof(breq)))