Hi,
the hostrt stuff did not compile on ARM, at this chance, I had a look
and found a few things which I did not like:
- the kernel-space and user-space did not use seqcount implementations
from the same header, and what is more, seqcount is not available on 2.4
kernels. Since we provide an implementation anyway, I changed the code
so that only this implementation is used both in kernel-space and
user-space. Prefixing everything with xn to avoid namespace clashes.
- the xnarch_hostrt_data also had two different definitions, one for
user-space, one for kernel-space, since this definition is supposed to
come from newer I-pipe in kernel-space, the code did not compile with
older I-pipe patches. I separated xnarch_hostrt_data, the structure
passed by the I-pipe to do_hostrt_event, from xnvdso_hostrt_data, the
structure, part of the vdso used for exchanges between user-space and
kernel-space. We can now get xnvdso_hostrt_data defined all the time. We
can probably even move xnvdso_hostrt_data definition to vdso.h
- avoided cycle_t and u32 in order to avoid user-space namespace
pollution and need for many typedefs with 2.4 kernels. Using unsigned
long long directly instead of cycle_t revealed a bug in clocktest.c.
Here is the patch.
diff --git a/include/nucleus/Makefile.am b/include/nucleus/Makefile.am
index 9a72b24..5fc1c21 100644
diff --git a/include/nucleus/Makefile.in b/include/nucleus/Makefile.in
index 5e93dc9..a6fa801 100644
diff --git a/include/nucleus/hostrt.h b/include/nucleus/hostrt.h
index 70ffbfe..85b8e88 100644
--- a/include/nucleus/hostrt.h
+++ b/include/nucleus/hostrt.h
@@ -23,32 +23,24 @@
* 02111-1307, USA.
*/
-#include <nucleus/types.h>
-#ifdef __KERNEL__
-#include <asm-generic/xenomai/system.h>
-#else /* !__KERNEL__ */
+#ifndef __KERNEL__
#include <time.h>
#include <sys/types.h>
-#include <nucleus/seqlock_user.h>
-typedef u_int32_t u32;
-typedef u_int64_t cycle_t;
+#else /* __KERNEL__ */
+#include <asm-generic/xenomai/system.h>
+#endif /* __KERNEL__ */
+#include <nucleus/seqlock.h>
-/*
- * xnarch_hostrt_data must be kept in sync with the corresponding ipipe
- * definitions in ipipe_tickdev.h We cannot directly include the file
- * here because the definitions are also required in Xenomai userland.
- */
-struct xnarch_hostrt_data {
+struct xnvdso_hostrt_data {
short live;
- seqcount_t seqcount;
+ xnseqcount_t seqcount;
time_t wall_time_sec;
- u32 wall_time_nsec;
+ unsigned wall_time_nsec;
struct timespec wall_to_monotonic;
- cycle_t cycle_last;
- cycle_t mask;
- u32 mult;
- u32 shift;
+ unsigned long long cycle_last;
+ unsigned long long mask;
+ unsigned mult;
+ unsigned shift;
};
-#endif /* !__KERNEL__ */
#endif
diff --git a/include/nucleus/seqlock.h b/include/nucleus/seqlock.h
new file mode 100644
index 0000000..897d411
--- /dev/null
+++ b/include/nucleus/seqlock.h
@@ -0,0 +1,57 @@
+#ifndef __SEQLOCK_H
+#define __SEQLOCK_H
+
+/* Originally from the linux kernel, adapted for userland and Xenomai */
+
+#include <asm/xenomai/atomic.h>
+
+typedef struct xnseqcount {
+ unsigned sequence;
+} xnseqcount_t;
+
+#define XNSEQCNT_ZERO { 0 }
+#define xnseqcount_init(x) do { *(x) = (xnseqcount_t) SEQCNT_ZERO; } while (0)
+
+/* Start of read using pointer to a sequence counter only. */
+static inline unsigned xnread_seqcount_begin(const xnseqcount_t *s)
+{
+ unsigned ret;
+
+repeat:
+ ret = s->sequence;
+ xnarch_read_memory_barrier();
+ if (unlikely(ret & 1)) {
+ cpu_relax();
+ goto repeat;
+ }
+ return ret;
+}
+
+/*
+ * Test if reader processed invalid data because sequence number has changed.
+ */
+static inline int xnread_seqcount_retry(const xnseqcount_t *s, unsigned start)
+{
+ xnarch_read_memory_barrier();
+
+ return s->sequence != start;
+}
+
+
+/*
+ * The sequence counter only protects readers from concurrent writers.
+ * Writers must use their own locking.
+ */
+static inline void xnwrite_seqcount_begin(xnseqcount_t *s)
+{
+ s->sequence++;
+ xnarch_write_memory_barrier();
+}
+
+static inline void xnwrite_seqcount_end(xnseqcount_t *s)
+{
+ xnarch_write_memory_barrier();
+ s->sequence++;
+}
+
+#endif /* __SEQLOCK_H */
diff --git a/include/nucleus/seqlock_user.h b/include/nucleus/seqlock_user.h
deleted file mode 100644
index 598d4da..0000000
--- a/include/nucleus/seqlock_user.h
+++ /dev/null
@@ -1,57 +0,0 @@
-#ifndef __SEQLOCK_USER_H
-#define __SEQLOCK_USER_H
-
-/* Originally from the linux kernel, adapted for userland and Xenomai */
-
-#include <asm/xenomai/atomic.h>
-
-typedef struct seqcount {
- unsigned sequence;
-} seqcount_t;
-
-#define SEQCNT_ZERO { 0 }
-#define seqcount_init(x) do { *(x) = (seqcount_t) SEQCNT_ZERO; } while (0)
-
-/* Start of read using pointer to a sequence counter only. */
-static inline unsigned read_seqcount_begin(const seqcount_t *s)
-{
- unsigned ret;
-
-repeat:
- ret = s->sequence;
- xnarch_read_memory_barrier();
- if (unlikely(ret & 1)) {
- cpu_relax();
- goto repeat;
- }
- return ret;
-}
-
-/*
- * Test if reader processed invalid data because sequence number has changed.
- */
-static inline int read_seqcount_retry(const seqcount_t *s, unsigned start)
-{
- xnarch_read_memory_barrier();
-
- return s->sequence != start;
-}
-
-
-/*
- * The sequence counter only protects readers from concurrent writers.
- * Writers must use their own locking.
- */
-static inline void write_seqcount_begin(seqcount_t *s)
-{
- s->sequence++;
- xnarch_write_memory_barrier();
-}
-
-static inline void write_seqcount_end(seqcount_t *s)
-{
- xnarch_write_memory_barrier();
- s->sequence++;
-}
-
-#endif
diff --git a/include/nucleus/vdso.h b/include/nucleus/vdso.h
index bce4c5a..279574b 100644
--- a/include/nucleus/vdso.h
+++ b/include/nucleus/vdso.h
@@ -34,7 +34,7 @@
struct xnvdso {
unsigned long long features;
- struct xnarch_hostrt_data hostrt_data;
+ struct xnvdso_hostrt_data hostrt_data;
/*
* Embed further domain specific structures that
* describe the shared data here
@@ -61,7 +61,7 @@ struct xnvdso {
extern struct xnvdso *nkvdso;
-static inline struct xnarch_hostrt_data *get_hostrt_data(void)
+static inline struct xnvdso_hostrt_data *get_hostrt_data(void)
{
return &nkvdso->hostrt_data;
}
diff --git a/ksrc/nucleus/module.c b/ksrc/nucleus/module.c
index 3f962ba..fc8ceac 100644
--- a/ksrc/nucleus/module.c
+++ b/ksrc/nucleus/module.c
@@ -69,7 +69,7 @@ static inline void do_hostrt_event(struct xnarch_hostrt_data
*hostrt)
*/
spin_lock_irqsave(&__hostrtlock, flags);
- write_seqcount_begin(&nkvdso->hostrt_data.seqcount);
+ xnwrite_seqcount_begin(&nkvdso->hostrt_data.seqcount);
nkvdso->hostrt_data.live = 1;
nkvdso->hostrt_data.cycle_last = hostrt->cycle_last;
@@ -80,7 +80,7 @@ static inline void do_hostrt_event(struct xnarch_hostrt_data
*hostrt)
nkvdso->hostrt_data.wall_time_nsec = hostrt->wall_time_nsec;
nkvdso->hostrt_data.wall_to_monotonic = hostrt->wall_to_monotonic;
- write_seqcount_end(&nkvdso->hostrt_data.seqcount);
+ xnwrite_seqcount_end(&nkvdso->hostrt_data.seqcount);
spin_unlock_irqrestore(&__hostrtlock, flags);
}
diff --git a/src/skins/posix/clock.c b/src/skins/posix/clock.c
index 7232c48..4f2171b 100644
--- a/src/skins/posix/clock.c
+++ b/src/skins/posix/clock.c
@@ -25,7 +25,6 @@
#include <time.h>
#include <asm/xenomai/arith.h>
#include <asm-generic/xenomai/timeconv.h>
-#include <nucleus/seqlock_user.h>
#include <sys/types.h>
#include <nucleus/vdso.h>
@@ -63,9 +62,9 @@ int __do_clock_host_realtime(struct timespec *ts, void *tzp)
{
#ifdef XNARCH_HAVE_NONPRIV_TSC
unsigned int seq;
- cycle_t now, base, mask, cycle_delta;
+ unsigned long long now, base, mask, cycle_delta;
unsigned long mult, shift, nsec, rem;
- struct xnarch_hostrt_data *hostrt_data;
+ struct xnvdso_hostrt_data *hostrt_data;
if (!xnvdso_test_feature(XNVDSO_FEAT_HOST_REALTIME))
return -1;
@@ -80,7 +79,7 @@ int __do_clock_host_realtime(struct timespec *ts, void *tzp)
* mechanism in the kernel.
*/
retry:
- seq = read_seqcount_begin(&hostrt_data->seqcount);
+ seq = xnread_seqcount_begin(&hostrt_data->seqcount);
now = __xn_rdtsc();
base = hostrt_data->cycle_last;
@@ -92,7 +91,7 @@ retry:
/* If the data changed during the read, try the
alternative data element */
- if (read_seqcount_retry(&hostrt_data->seqcount, seq))
+ if (xnread_seqcount_retry(&hostrt_data->seqcount, seq))
goto retry;
cycle_delta = (now - base) & mask;
diff --git a/src/testsuite/clocktest/clocktest.c
b/src/testsuite/clocktest/clocktest.c
index bf4feb6..038cfbc 100644
--- a/src/testsuite/clocktest/clocktest.c
+++ b/src/testsuite/clocktest/clocktest.c
@@ -99,8 +99,8 @@ static void show_hostrt_diagnostics(void)
(intmax_t)nkvdso->hostrt_data.wall_to_monotonic.tv_sec);
printf(" tv_nsec : %ld\n",
nkvdso->hostrt_data.wall_to_monotonic.tv_nsec);
- printf("cycle_last : %lu\n", nkvdso->hostrt_data.cycle_last);
- printf("mask : 0x%lx\n", nkvdso->hostrt_data.mask);
+ printf("cycle_last : %Lu\n", nkvdso->hostrt_data.cycle_last);
+ printf("mask : 0x%Lx\n", nkvdso->hostrt_data.mask);
printf("mult : %u\n", nkvdso->hostrt_data.mult);
printf("shift : %u\n\n", nkvdso->hostrt_data.shift);
}
Everybody OK?
--
Gilles.
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