mirror_ubuntu-kernels/kernel
Lakshmi Sowjanya D 02ecee07ca timekeeping: Add function to convert realtime to base clock
PPS (Pulse Per Second) generates a hardware pulse every second based on
CLOCK_REALTIME. This works fine when the pulse is generated in software
from a hrtimer callback function.

For hardware which generates the pulse by programming a timer it is
required to convert CLOCK_REALTIME to the underlying hardware clock.

The X86 Timed IO device is based on the Always Running Timer (ART), which
is the base clock of the TSC, which is usually the system clocksource on
X86.

The core code already has functionality to convert base clock timestamps to
system clocksource timestamps, but there is no support for converting the
other way around.

Provide the required functionality to support such devices in a generic
way to avoid code duplication in drivers:

  1) ktime_real_to_base_clock() to convert a CLOCK_REALTIME timestamp to a
     base clock timestamp

  2) timekeeping_clocksource_has_base() to allow drivers to validate that
     the system clocksource is based on a particular clocksource ID.

[ tglx: Simplify timekeeping_clocksource_has_base() and add missing READ_ONCE() ]

Co-developed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Christopher S. Hall <christopher.s.hall@intel.com>
Signed-off-by: Christopher S. Hall <christopher.s.hall@intel.com>
Signed-off-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240513103813.5666-10-lakshmi.sowjanya.d@intel.com
2024-06-03 11:18:51 +02:00
..
bpf bpf-for-netdev 2024-05-27 16:26:30 -07:00
cgroup Misc fixes: 2024-05-19 11:38:15 -07:00
configs hardening updates for 6.10-rc1 2024-05-13 14:14:05 -07:00
debug kdb: Simplify management of tmpbuffer in kdb_read() 2024-04-26 17:13:31 +01:00
dma dma-mapping: benchmark: handle NUMA_NO_NODE correctly 2024-05-23 15:06:48 +02:00
entry entry: Respect changes to system call number by trace_sys_enter() 2024-03-12 13:23:32 +01:00
events The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
futex printk: Change type of CONFIG_BASE_SMALL to bool 2024-05-06 17:39:09 +02:00
gcov gcov: annotate struct gcov_iterator with __counted_by 2023-10-18 14:43:22 -07:00
irq genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after() 2024-05-24 12:49:35 +02:00
kcsan kcsan, compiler_types: Introduce __data_racy type qualifier 2024-05-07 11:39:50 -07:00
livepatch livepatch: Rename KLP_* to KLP_TRANSITION_* 2024-05-09 15:48:01 +02:00
locking - Core Frameworks 2024-05-22 10:49:54 -07:00
module Driver core changes for 6.10-rc1 2024-05-22 12:13:40 -07:00
power vfs-6.10-rc2.fixes 2024-05-27 08:09:12 -07:00
printk TTY/Serial changes for 6.10-rc1 2024-05-22 11:53:02 -07:00
rcu Merge branches 'fixes.2024.04.15a', 'misc.2024.04.12a', 'rcu-sync-normal-improve.2024.04.15a', 'rcu-tasks.2024.04.15a' and 'rcutorture.2024.04.15a' into rcu-merge.2024.04.15a 2024-05-01 13:04:02 +02:00
sched bitmap patches for 6.10 2024-05-21 15:29:01 -07:00
time timekeeping: Add function to convert realtime to base clock 2024-06-03 11:18:51 +02:00
trace Including fixes from bpf and netfilter. 2024-05-30 08:33:04 -07:00
.gitignore
acct.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
async.c async: Use a dedicated unbound workqueue with raised min_active 2024-02-09 11:13:59 -10:00
audit_fsnotify.c
audit_tree.c fsnotify: create a wrapper fsnotify_find_inode_mark() 2024-04-04 16:24:16 +02:00
audit_watch.c fsnotify: create a wrapper fsnotify_find_inode_mark() 2024-04-04 16:24:16 +02:00
audit.c audit: use KMEM_CACHE() instead of kmem_cache_create() 2024-01-25 10:12:22 -05:00
audit.h audit: correct audit_filter_inodes() definition 2023-07-21 12:17:25 -04:00
auditfilter.c audit: remove unnecessary assignment in audit_dupe_lsm_field() 2024-01-25 09:59:27 -05:00
auditsc.c audit,io_uring: io_uring openat triggers audit reference count underflow 2023-10-13 18:34:46 +02:00
backtracetest.c backtracetest: Convert from tasklet to BH workqueue 2024-02-05 13:22:34 -10:00
bounds.c bounds: Use the right number of bits for power-of-two CONFIG_NR_CPUS 2024-04-29 08:29:29 -07:00
capability.c lsm: constify the 'target' parameter in security_capget() 2023-08-08 16:48:47 -04:00
cfi.c
compat.c
configs.c
context_tracking.c context_tracking: Make context_tracking_key __ro_after_init 2024-03-22 11:18:18 +01:00
cpu_pm.c
cpu.c cgroup: Changes for v6.10 2024-05-15 17:06:08 -07:00
crash_core.c Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
crash_reserve.c crash: add prefix for crash dumping messages 2024-05-08 08:41:26 -07:00
cred.c cred: Use KMEM_CACHE() instead of kmem_cache_create() 2024-02-23 17:33:31 -05:00
delayacct.c delayacct: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:54 +02:00
dma.c
elfcorehdr.c crash: remove dependency of FA_DUMP on CRASH_DUMP 2024-02-23 17:48:22 -08:00
exec_domain.c
exit.c virtio: features, fixes, cleanups 2024-05-23 12:04:36 -07:00
exit.h exit: add internal include file with helpers 2023-09-21 12:03:50 -06:00
extable.c
fail_function.c
fork.c mm: rename mm_put_huge_zero_page to mm_put_huge_zero_folio 2024-04-25 20:56:20 -07:00
freezer.c Linux 6.7-rc6 2023-12-23 15:52:13 +01:00
gen_kheaders.sh kheaders: use command -v to test for existence of cpio 2024-05-30 01:13:20 +09:00
groups.c groups: Convert group_info.usage to refcount_t 2023-09-29 11:28:39 -07:00
hung_task.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
iomem.c kernel/iomem.c: remove __weak ioremap_cache helper 2023-08-21 13:37:28 -07:00
irq_work.c
jump_label.c jump_label,module: Don't alloc static_key_mod for __ro_after_init keys 2024-03-22 11:18:16 +01:00
kallsyms_internal.h kallsyms: Avoid weak references for kallsyms symbols 2024-05-02 19:48:26 +09:00
kallsyms_selftest.c mm: vmalloc: enable memory allocation profiling 2024-04-25 20:55:57 -07:00
kallsyms_selftest.h
kallsyms.c kallsyms: Avoid weak references for kallsyms symbols 2024-05-02 19:48:26 +09:00
kcmp.c file: convert to SLAB_TYPESAFE_BY_RCU 2023-10-19 11:02:48 +02:00
Kconfig.freezer
Kconfig.hz
Kconfig.kexec crash: clean up kdump related config items 2024-02-23 17:48:22 -08:00
Kconfig.locks
Kconfig.preempt
kcov.c kcov: avoid clang out-of-range warning 2024-04-25 21:07:04 -07:00
kexec_core.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
kexec_elf.c
kexec_file.c crash: add a new kexec flag for hotplug support 2024-04-23 14:59:01 +10:00
kexec_internal.h crash: remove dependency of FA_DUMP on CRASH_DUMP 2024-02-23 17:48:22 -08:00
kexec.c crash: add a new kexec flag for hotplug support 2024-04-23 14:59:01 +10:00
kheaders.c
kprobes.c kprobe/ftrace: fix build error due to bad function definition 2024-05-17 19:17:55 -07:00
ksyms_common.c kallsyms: make kallsyms_show_value() as generic function 2023-06-08 12:27:20 -07:00
ksysfs.c vmlinux: Avoid weak reference to notes section 2024-05-02 19:48:26 +09:00
kthread.c kunit: Handle test faults 2024-05-06 14:22:02 -06:00
latencytop.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
Makefile crash: split crash dumping code out from kexec_core.c 2024-02-23 17:48:22 -08:00
module_signature.c
notifier.c
nsproxy.c pidfd: add pidfs 2024-03-01 12:23:37 +01:00
numa.c kernel/numa.c: Move logging out of numa.h 2023-12-20 19:26:30 -05:00
padata.c padata: Disable BH when taking works lock on MT path 2024-04-12 15:07:51 +08:00
panic.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
params.c params: Fix multi-line comment style 2023-12-01 09:51:44 -08:00
pid_namespace.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
pid_sysctl.h kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
pid.c pidfs: remove config option 2024-03-13 12:53:53 -07:00
profile.c profiling: Remove create_prof_cpu_mask(). 2024-04-27 11:17:48 -07:00
ptrace.c ptrace_attach: shift send(SIGSTOP) into ptrace_set_stopped() 2024-02-22 15:38:52 -08:00
range.c
reboot.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
regset.c regset: use kvzalloc() for regset_get_alloc() 2024-04-25 21:07:03 -07:00
relay.c kernel: relay: remove relay_file_splice_read dead code, doesn't work 2023-12-29 12:22:27 -08:00
resource_kunit.c
resource.c Quite a lot of kexec work this time around. Many singleton patches in 2024-01-09 11:46:20 -08:00
rseq.c
scftorture.c scftorture: Pause testing after memory-allocation failure 2023-07-14 15:02:57 -07:00
scs.c
seccomp.c sysctl changes for v6.10-rc1 2024-05-17 17:31:24 -07:00
signal.c virtio: features, fixes, cleanups 2024-05-23 12:04:36 -07:00
smp.c CSD lock commits for v6.7 2023-10-30 17:56:53 -10:00
smpboot.c kthread: add kthread_stop_put 2023-10-04 10:41:57 -07:00
smpboot.h
softirq.c softirq: Fix suspicious RCU usage in __do_softirq() 2024-04-29 05:03:51 +02:00
stackleak.c sysctl changes for v6.10-rc1 2024-05-17 17:31:24 -07:00
stacktrace.c stacktrace: fix kernel-doc typo 2023-12-29 12:22:29 -08:00
static_call_inline.c
static_call.c
stop_machine.c
sys_ni.c mseal: wire up mseal syscall 2024-05-23 19:40:26 -07:00
sys.c RISC-V Patches for the 6.10 Merge Window, Part 1 2024-05-22 09:56:00 -07:00
sysctl-test.c
sysctl.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
task_work.c task_work: add kerneldoc annotation for 'data' argument 2023-09-19 13:21:32 -07:00
taskstats.c taskstats: fill_stats_for_tgid: use for_each_thread() 2023-10-04 10:41:57 -07:00
torture.c torture: Print out torture module parameters 2023-09-24 17:24:01 +02:00
tracepoint.c
tsacct.c
ucount.c sysctl changes for v6.10-rc1 2024-05-17 17:31:24 -07:00
uid16.c
uid16.h
umh.c umh: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
up.c smp: Change function signatures to use call_single_data_t 2023-09-13 14:59:24 +02:00
user_namespace.c user_namespace: remove unnecessary NULL values from kbuf 2024-02-22 15:38:52 -08:00
user-return-notifier.c
user.c printk: Change type of CONFIG_BASE_SMALL to bool 2024-05-06 17:39:09 +02:00
usermode_driver.c
utsname_sysctl.c kernel misc: Remove the now superfluous sentinel elements from ctl_table array 2024-04-24 09:43:53 +02:00
utsname.c
vhost_task.c vhost_task: Handle SIGKILL by flushing work and exiting 2024-05-22 08:31:15 -04:00
vmcore_info.c mm: free up PG_slab 2024-04-25 20:56:00 -07:00
watch_queue.c watch_queue: fix kcalloc() arguments order 2023-12-21 13:17:54 +01:00
watchdog_buddy.c watchdog/hardlockup: move SMP barriers from common code to buddy code 2023-06-19 16:25:28 -07:00
watchdog_perf.c kernel/watchdog_perf.c: tidy up kerneldoc 2024-05-08 08:41:29 -07:00
watchdog.c Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
workqueue_internal.h workqueue: Drop the special locking rule for worker->flags and worker_pool->flags 2023-08-07 15:57:22 -10:00
workqueue.c Merge branch 'for-6.10' into test-merge-for-6.10 2024-05-15 11:40:33 -10:00