[PATCH v2] uapi, posix-timers: provide clockid-related macros and functions to UAPI

From: Eugene Syromiatnikov
Date: Mon Sep 23 2019 - 09:05:58 EST


As of now, there is no interface exposed for converting pid/fd into
clockid and vice versa; linuxptp, for example, has been carrying these
definitions in missing.h header for quite some time[1].

[1] https://sourceforge.net/p/linuxptp/code/ci/af380e86/tree/missing.h

Signed-off-by: Eugene Syromiatnikov <esyr@xxxxxxxxxx>
---
Changes since v1[1]:
* Actually tried to build with the patch and fixed the build error
reported by kbuild test robot[2].

[1] https://lkml.org/lkml/2019/9/20/698
[2] https://lkml.org/lkml/2019/9/22/13
---
include/linux/posix-timers.h | 47 +------------------------------------------
include/uapi/linux/time.h | 48 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 49 insertions(+), 46 deletions(-)

diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 3d10c84..ddc7e6e6 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -4,58 +4,13 @@

#include <linux/spinlock.h>
#include <linux/list.h>
+#include <linux/time.h>
#include <linux/alarmtimer.h>
#include <linux/timerqueue.h>

struct kernel_siginfo;
struct task_struct;

-/*
- * Bit fields within a clockid:
- *
- * The most significant 29 bits hold either a pid or a file descriptor.
- *
- * Bit 2 indicates whether a cpu clock refers to a thread or a process.
- *
- * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
- *
- * A clockid is invalid if bits 2, 1, and 0 are all set.
- */
-#define CPUCLOCK_PID(clock) ((pid_t) ~((clock) >> 3))
-#define CPUCLOCK_PERTHREAD(clock) \
- (((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
-
-#define CPUCLOCK_PERTHREAD_MASK 4
-#define CPUCLOCK_WHICH(clock) ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
-#define CPUCLOCK_CLOCK_MASK 3
-#define CPUCLOCK_PROF 0
-#define CPUCLOCK_VIRT 1
-#define CPUCLOCK_SCHED 2
-#define CPUCLOCK_MAX 3
-#define CLOCKFD CPUCLOCK_MAX
-#define CLOCKFD_MASK (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)
-
-static inline clockid_t make_process_cpuclock(const unsigned int pid,
- const clockid_t clock)
-{
- return ((~pid) << 3) | clock;
-}
-static inline clockid_t make_thread_cpuclock(const unsigned int tid,
- const clockid_t clock)
-{
- return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK);
-}
-
-static inline clockid_t fd_to_clockid(const int fd)
-{
- return make_process_cpuclock((unsigned int) fd, CLOCKFD);
-}
-
-static inline int clockid_to_fd(const clockid_t clk)
-{
- return ~(clk >> 3);
-}
-
#ifdef CONFIG_POSIX_TIMERS

/**
diff --git a/include/uapi/linux/time.h b/include/uapi/linux/time.h
index 958932e..58a78a7 100644
--- a/include/uapi/linux/time.h
+++ b/include/uapi/linux/time.h
@@ -70,4 +70,52 @@ struct itimerval {
*/
#define TIMER_ABSTIME 0x01

+/*
+ * Bit fields within a clockid:
+ *
+ * The most significant 29 bits hold either a pid or a file descriptor.
+ *
+ * Bit 2 indicates whether a cpu clock refers to a thread or a process.
+ *
+ * Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
+ *
+ * A clockid is invalid if bits 2, 1, and 0 are all set.
+ */
+#define CPUCLOCK_PID(clock) ((pid_t) ~((clock) >> 3))
+#define CPUCLOCK_PERTHREAD(clock) \
+ (((clock) & (__kernel_clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
+
+#define CPUCLOCK_PERTHREAD_MASK 4
+#define CPUCLOCK_WHICH(clock) \
+ ((clock) & (__kernel_clockid_t) CPUCLOCK_CLOCK_MASK)
+#define CPUCLOCK_CLOCK_MASK 3
+#define CPUCLOCK_PROF 0
+#define CPUCLOCK_VIRT 1
+#define CPUCLOCK_SCHED 2
+#define CPUCLOCK_MAX 3
+#define CLOCKFD CPUCLOCK_MAX
+#define CLOCKFD_MASK (CPUCLOCK_PERTHREAD_MASK|CPUCLOCK_CLOCK_MASK)
+
+static inline __kernel_clockid_t make_process_cpuclock(const unsigned int pid,
+ const clockid_t clock)
+{
+ return ((~pid) << 3) | clock;
+}
+static inline __kernel_clockid_t make_thread_cpuclock(const unsigned int tid,
+ const clockid_t clock)
+{
+ return make_process_cpuclock(tid, clock | CPUCLOCK_PERTHREAD_MASK);
+}
+
+static inline __kernel_clockid_t fd_to_clockid(const int fd)
+{
+ return make_process_cpuclock((unsigned int) fd, CLOCKFD);
+}
+
+static inline int clockid_to_fd(const __kernel_clockid_t clk)
+{
+ return ~(clk >> 3);
+}
+
+
#endif /* _UAPI_LINUX_TIME_H */
--
2.1.4