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authorLinus Torvalds <torvalds@linux-foundation.org>2022-12-12 12:52:02 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-12-12 12:52:02 -0800
commit0a1d4434db5f86c50018fe0aab299ac97dc15b76 (patch)
tree69574d3ef27cbf6527bcc38cd035d8bdf854203c /Documentation
parent79ad89123c2523a7982d457641dd64f339307e6c (diff)
parent18a207849218d8c15072f449e6d0b901262290c9 (diff)
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Merge tag 'timers-core-2022-12-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner: "Updates for timers, timekeeping and drivers: Core: - The timer_shutdown[_sync]() infrastructure: Tearing down timers can be tedious when there are circular dependencies to other things which need to be torn down. A prime example is timer and workqueue where the timer schedules work and the work arms the timer. What needs to prevented is that pending work which is drained via destroy_workqueue() does not rearm the previously shutdown timer. Nothing in that shutdown sequence relies on the timer being functional. The conclusion was that the semantics of timer_shutdown_sync() should be: - timer is not enqueued - timer callback is not running - timer cannot be rearmed Preventing the rearming of shutdown timers is done by discarding rearm attempts silently. A warning for the case that a rearm attempt of a shutdown timer is detected would not be really helpful because it's entirely unclear how it should be acted upon. The only way to address such a case is to add 'if (in_shutdown)' conditionals all over the place. This is error prone and in most cases of teardown not required all. - The real fix for the bluetooth HCI teardown based on timer_shutdown_sync(). A larger scale conversion to timer_shutdown_sync() is work in progress. - Consolidation of VDSO time namespace helper functions - Small fixes for timer and timerqueue Drivers: - Prevent integer overflow on the XGene-1 TVAL register which causes an never ending interrupt storm. - The usual set of new device tree bindings - Small fixes and improvements all over the place" * tag 'timers-core-2022-12-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) dt-bindings: timer: renesas,cmt: Add r8a779g0 CMT support dt-bindings: timer: renesas,tmu: Add r8a779g0 support clocksource/drivers/arm_arch_timer: Use kstrtobool() instead of strtobool() clocksource/drivers/timer-ti-dm: Fix missing clk_disable_unprepare in dmtimer_systimer_init_clock() clocksource/drivers/timer-ti-dm: Clear settings on probe and free clocksource/drivers/timer-ti-dm: Make timer_get_irq static clocksource/drivers/timer-ti-dm: Fix warning for omap_timer_match clocksource/drivers/arm_arch_timer: Fix XGene-1 TVAL register math error clocksource/drivers/timer-npcm7xx: Enable timer 1 clock before use dt-bindings: timer: nuvoton,npcm7xx-timer: Allow specifying all clocks dt-bindings: timer: rockchip: Add rockchip,rk3128-timer clockevents: Repair kernel-doc for clockevent_delta2ns() clocksource/drivers/ingenic-ost: Define pm functions properly in platform_driver struct clocksource/drivers/sh_cmt: Access registers according to spec vdso/timens: Refactor copy-pasted find_timens_vvar_page() helper into one copy Bluetooth: hci_qca: Fix the teardown problem for real timers: Update the documentation to reflect on the new timer_shutdown() API timers: Provide timer_shutdown[_sync]() timers: Add shutdown mechanism to the internal functions timers: Split [try_to_]del_timer[_sync]() to prepare for shutdown mode ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/RCU/Design/Requirements/Requirements.rst2
-rw-r--r--Documentation/core-api/local_ops.rst2
-rw-r--r--Documentation/devicetree/bindings/timer/nuvoton,npcm7xx-timer.yaml8
-rw-r--r--Documentation/devicetree/bindings/timer/renesas,cmt.yaml2
-rw-r--r--Documentation/devicetree/bindings/timer/renesas,tmu.yaml1
-rw-r--r--Documentation/devicetree/bindings/timer/rockchip,rk-timer.yaml1
-rw-r--r--Documentation/kernel-hacking/locking.rst17
-rw-r--r--Documentation/timers/hrtimers.rst2
-rw-r--r--Documentation/translations/it_IT/kernel-hacking/locking.rst14
-rw-r--r--Documentation/translations/zh_CN/core-api/local_ops.rst2
10 files changed, 31 insertions, 20 deletions
diff --git a/Documentation/RCU/Design/Requirements/Requirements.rst b/Documentation/RCU/Design/Requirements/Requirements.rst
index a0f8164c8513..49387d823619 100644
--- a/Documentation/RCU/Design/Requirements/Requirements.rst
+++ b/Documentation/RCU/Design/Requirements/Requirements.rst
@@ -1858,7 +1858,7 @@ unloaded. After a given module has been unloaded, any attempt to call
one of its functions results in a segmentation fault. The module-unload
functions must therefore cancel any delayed calls to loadable-module
functions, for example, any outstanding mod_timer() must be dealt
-with via del_timer_sync() or similar.
+with via timer_shutdown_sync() or similar.
Unfortunately, there is no way to cancel an RCU callback; once you
invoke call_rcu(), the callback function is eventually going to be
diff --git a/Documentation/core-api/local_ops.rst b/Documentation/core-api/local_ops.rst
index 2ac3f9f29845..0b42ceaaf3c4 100644
--- a/Documentation/core-api/local_ops.rst
+++ b/Documentation/core-api/local_ops.rst
@@ -191,7 +191,7 @@ Here is a sample module which implements a basic per cpu counter using
static void __exit test_exit(void)
{
- del_timer_sync(&test_timer);
+ timer_shutdown_sync(&test_timer);
}
module_init(test_init);
diff --git a/Documentation/devicetree/bindings/timer/nuvoton,npcm7xx-timer.yaml b/Documentation/devicetree/bindings/timer/nuvoton,npcm7xx-timer.yaml
index 737af78ad70c..d53e1bb98b8a 100644
--- a/Documentation/devicetree/bindings/timer/nuvoton,npcm7xx-timer.yaml
+++ b/Documentation/devicetree/bindings/timer/nuvoton,npcm7xx-timer.yaml
@@ -25,7 +25,13 @@ properties:
- description: The timer interrupt of timer 0
clocks:
- maxItems: 1
+ items:
+ - description: The reference clock for timer 0
+ - description: The reference clock for timer 1
+ - description: The reference clock for timer 2
+ - description: The reference clock for timer 3
+ - description: The reference clock for timer 4
+ minItems: 1
required:
- compatible
diff --git a/Documentation/devicetree/bindings/timer/renesas,cmt.yaml b/Documentation/devicetree/bindings/timer/renesas,cmt.yaml
index bde6c9b66bf4..a0be1755ea28 100644
--- a/Documentation/devicetree/bindings/timer/renesas,cmt.yaml
+++ b/Documentation/devicetree/bindings/timer/renesas,cmt.yaml
@@ -102,12 +102,14 @@ properties:
- enum:
- renesas,r8a779a0-cmt0 # 32-bit CMT0 on R-Car V3U
- renesas,r8a779f0-cmt0 # 32-bit CMT0 on R-Car S4-8
+ - renesas,r8a779g0-cmt0 # 32-bit CMT0 on R-Car V4H
- const: renesas,rcar-gen4-cmt0 # 32-bit CMT0 on R-Car Gen4
- items:
- enum:
- renesas,r8a779a0-cmt1 # 48-bit CMT on R-Car V3U
- renesas,r8a779f0-cmt1 # 48-bit CMT on R-Car S4-8
+ - renesas,r8a779g0-cmt1 # 48-bit CMT on R-Car V4H
- const: renesas,rcar-gen4-cmt1 # 48-bit CMT on R-Car Gen4
reg:
diff --git a/Documentation/devicetree/bindings/timer/renesas,tmu.yaml b/Documentation/devicetree/bindings/timer/renesas,tmu.yaml
index 60f4c059bcff..a67e427a9e7e 100644
--- a/Documentation/devicetree/bindings/timer/renesas,tmu.yaml
+++ b/Documentation/devicetree/bindings/timer/renesas,tmu.yaml
@@ -38,6 +38,7 @@ properties:
- renesas,tmu-r8a77995 # R-Car D3
- renesas,tmu-r8a779a0 # R-Car V3U
- renesas,tmu-r8a779f0 # R-Car S4-8
+ - renesas,tmu-r8a779g0 # R-Car V4H
- const: renesas,tmu
reg:
diff --git a/Documentation/devicetree/bindings/timer/rockchip,rk-timer.yaml b/Documentation/devicetree/bindings/timer/rockchip,rk-timer.yaml
index dc3bc1e62fe9..b61ed1a431bb 100644
--- a/Documentation/devicetree/bindings/timer/rockchip,rk-timer.yaml
+++ b/Documentation/devicetree/bindings/timer/rockchip,rk-timer.yaml
@@ -18,6 +18,7 @@ properties:
- enum:
- rockchip,rv1108-timer
- rockchip,rk3036-timer
+ - rockchip,rk3128-timer
- rockchip,rk3188-timer
- rockchip,rk3228-timer
- rockchip,rk3229-timer
diff --git a/Documentation/kernel-hacking/locking.rst b/Documentation/kernel-hacking/locking.rst
index 6805ae6e86e6..c756786e17ae 100644
--- a/Documentation/kernel-hacking/locking.rst
+++ b/Documentation/kernel-hacking/locking.rst
@@ -967,7 +967,7 @@ you might do the following::
while (list) {
struct foo *next = list->next;
- del_timer(&list->timer);
+ timer_delete(&list->timer);
kfree(list);
list = next;
}
@@ -981,7 +981,7 @@ the lock after we spin_unlock_bh(), and then try to free
the element (which has already been freed!).
This can be avoided by checking the result of
-del_timer(): if it returns 1, the timer has been deleted.
+timer_delete(): if it returns 1, the timer has been deleted.
If 0, it means (in this case) that it is currently running, so we can
do::
@@ -990,7 +990,7 @@ do::
while (list) {
struct foo *next = list->next;
- if (!del_timer(&list->timer)) {
+ if (!timer_delete(&list->timer)) {
/* Give timer a chance to delete this */
spin_unlock_bh(&list_lock);
goto retry;
@@ -1005,9 +1005,12 @@ do::
Another common problem is deleting timers which restart themselves (by
calling add_timer() at the end of their timer function).
Because this is a fairly common case which is prone to races, you should
-use del_timer_sync() (``include/linux/timer.h``) to
-handle this case. It returns the number of times the timer had to be
-deleted before we finally stopped it from adding itself back in.
+use timer_delete_sync() (``include/linux/timer.h``) to handle this case.
+
+Before freeing a timer, timer_shutdown() or timer_shutdown_sync() should be
+called which will keep it from being rearmed. Any subsequent attempt to
+rearm the timer will be silently ignored by the core code.
+
Locking Speed
=============
@@ -1335,7 +1338,7 @@ lock.
- kfree()
-- add_timer() and del_timer()
+- add_timer() and timer_delete()
Mutex API reference
===================
diff --git a/Documentation/timers/hrtimers.rst b/Documentation/timers/hrtimers.rst
index c1c20a693e8f..7ac448908d1f 100644
--- a/Documentation/timers/hrtimers.rst
+++ b/Documentation/timers/hrtimers.rst
@@ -118,7 +118,7 @@ existing timer wheel code, as it is mature and well suited. Sharing code
was not really a win, due to the different data structures. Also, the
hrtimer functions now have clearer behavior and clearer names - such as
hrtimer_try_to_cancel() and hrtimer_cancel() [which are roughly
-equivalent to del_timer() and del_timer_sync()] - so there's no direct
+equivalent to timer_delete() and timer_delete_sync()] - so there's no direct
1:1 mapping between them on the algorithmic level, and thus no real
potential for code sharing either.
diff --git a/Documentation/translations/it_IT/kernel-hacking/locking.rst b/Documentation/translations/it_IT/kernel-hacking/locking.rst
index 51af37f2d621..b8ecf41273c5 100644
--- a/Documentation/translations/it_IT/kernel-hacking/locking.rst
+++ b/Documentation/translations/it_IT/kernel-hacking/locking.rst
@@ -990,7 +990,7 @@ potreste fare come segue::
while (list) {
struct foo *next = list->next;
- del_timer(&list->timer);
+ timer_delete(&list->timer);
kfree(list);
list = next;
}
@@ -1003,7 +1003,7 @@ e prenderà il *lock* solo dopo spin_unlock_bh(), e cercherà
di eliminare il suo oggetto (che però è già stato eliminato).
Questo può essere evitato controllando il valore di ritorno di
-del_timer(): se ritorna 1, il temporizzatore è stato già
+timer_delete(): se ritorna 1, il temporizzatore è stato già
rimosso. Se 0, significa (in questo caso) che il temporizzatore è in
esecuzione, quindi possiamo fare come segue::
@@ -1012,7 +1012,7 @@ esecuzione, quindi possiamo fare come segue::
while (list) {
struct foo *next = list->next;
- if (!del_timer(&list->timer)) {
+ if (!timer_delete(&list->timer)) {
/* Give timer a chance to delete this */
spin_unlock_bh(&list_lock);
goto retry;
@@ -1026,10 +1026,8 @@ esecuzione, quindi possiamo fare come segue::
Un altro problema è l'eliminazione dei temporizzatori che si riavviano
da soli (chiamando add_timer() alla fine della loro esecuzione).
Dato che questo è un problema abbastanza comune con una propensione
-alle corse critiche, dovreste usare del_timer_sync()
-(``include/linux/timer.h``) per gestire questo caso. Questa ritorna il
-numero di volte che il temporizzatore è stato interrotto prima che
-fosse in grado di fermarlo senza che si riavviasse.
+alle corse critiche, dovreste usare timer_delete_sync()
+(``include/linux/timer.h``) per gestire questo caso.
Velocità della sincronizzazione
===============================
@@ -1374,7 +1372,7 @@ contesto, o trattenendo un qualsiasi *lock*.
- kfree()
-- add_timer() e del_timer()
+- add_timer() e timer_delete()
Riferimento per l'API dei Mutex
===============================
diff --git a/Documentation/translations/zh_CN/core-api/local_ops.rst b/Documentation/translations/zh_CN/core-api/local_ops.rst
index 41e4525038e8..eb5423f60f17 100644
--- a/Documentation/translations/zh_CN/core-api/local_ops.rst
+++ b/Documentation/translations/zh_CN/core-api/local_ops.rst
@@ -185,7 +185,7 @@ UP之间没有不同的行为,在你的架构的 ``local.h`` 中包括 ``asm-g
static void __exit test_exit(void)
{
- del_timer_sync(&test_timer);
+ timer_shutdown_sync(&test_timer);
}
module_init(test_init);