kernel/drivers/counter/interrupt-cnt.c, branch linux-rolling-stable

counter: interrupt-cnt: Drop IRQF_NO_THREAD flag

2026-01-17T15:35:12Z

commit 23f9485510c338476b9735d516c1d4aacb810d46 upstream. An IRQ handler can either be IRQF_NO_THREAD or acquire spinlock_t, as CONFIG_PROVE_RAW_LOCK_NESTING warns: ============================= [ BUG: Invalid wait context ] 6.18.0-rc1+git... #1 ----------------------------- some-user-space-process/1251 is trying to lock: (&counter->events_list_lock){....}-{3:3}, at: counter_push_event [counter] other info that might help us debug this: context-{2:2} no locks held by some-user-space-process/.... stack backtrace: CPU: 0 UID: 0 PID: 1251 Comm: some-user-space-process 6.18.0-rc1+git... #1 PREEMPT Call trace: show_stack (C) dump_stack_lvl dump_stack __lock_acquire lock_acquire _raw_spin_lock_irqsave counter_push_event [counter] interrupt_cnt_isr [interrupt_cnt] __handle_irq_event_percpu handle_irq_event handle_simple_irq handle_irq_desc generic_handle_domain_irq gpio_irq_handler handle_irq_desc generic_handle_domain_irq gic_handle_irq call_on_irq_stack do_interrupt_handler el0_interrupt __el0_irq_handler_common el0t_64_irq_handler el0t_64_irq ... and Sebastian correctly points out. Remove IRQF_NO_THREAD as an alternative to switching to raw_spinlock_t, because the latter would limit all potential nested locks to raw_spinlock_t only. Cc: Sebastian Andrzej Siewior Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20251117151314.xwLAZrWY@linutronix.de/ Fixes: a55ebd47f21f ("counter: add IRQ or GPIO based counter") Signed-off-by: Alexander Sverdlin Reviewed-by: Sebastian Andrzej Siewior Reviewed-by: Oleksij Rempel Link: https://lore.kernel.org/r/20251118083603.778626-1-alexander.sverdlin@siemens.com Signed-off-by: William Breathitt Gray Signed-off-by: Greg Kroah-Hartman

Merge tag 'counter-updates-for-6.16' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wbg/counter into char-misc-next

2025-05-21T12:07:53Z

William writes: Counter updates for 6.16 An update to allow for larger count values in interrupt-cnt. * tag 'counter-updates-for-6.16' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wbg/counter: counter: interrupt-cnt: Convert atomic_t -> atomic_long_t

counter: interrupt-cnt: Protect enable/disable OPs with mutex

2025-05-02T23:45:11Z

Enable/disable seems to be racy on SMP, consider the following scenario: CPU0 CPU1 interrupt_cnt_enable_write(true) { if (priv->enabled == enable) return 0; if (enable) { priv->enabled = true; interrupt_cnt_enable_write(false) { if (priv->enabled == enable) return 0; if (enable) { priv->enabled = true; enable_irq(priv->irq); } else { disable_irq(priv->irq) priv->enabled = false; } enable_irq(priv->irq); } else { disable_irq(priv->irq); priv->enabled = false; } The above would result in priv->enabled == false, but IRQ left enabled. Protect both write (above race) and read (to propagate the value on SMP) callbacks with a mutex. Signed-off-by: Alexander Sverdlin Fixes: a55ebd47f21f ("counter: add IRQ or GPIO based counter") Acked-by: Oleksij Rempel Link: https://lore.kernel.org/r/20250331163642.2382651-1-alexander.sverdlin@siemens.com Signed-off-by: William Breathitt Gray

counter: interrupt-cnt: Convert atomic_t -> atomic_long_t

2025-05-02T13:46:01Z

Convert the internal counter type to atomic_long_t, which: - doesn't change much for existing in-tree users as they are 32-bit anyway (stm32/i.MX6) - doesn't introduce performace penalty on 32-bit platforms - provides 64-bit resolution on 64-bit platforms with virtually no preformance penalty Signed-off-by: Alexander Sverdlin Acked-by: Oleksij Rempel Link: https://lore.kernel.org/r/20250331152222.2263776-1-alexander.sverdlin@siemens.com Signed-off-by: William Breathitt Gray

module: Convert symbol namespace to string literal

2024-12-02T19:34:44Z

Clean up the existing export namespace code along the same lines of commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo) to __section("foo")") and for the same reason, it is not desired for the namespace argument to be a macro expansion itself. Scripted using git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file; do awk -i inplace ' /^#define EXPORT_SYMBOL_NS/ { gsub(/__stringify$ns$/, "ns"); print; next; } /^#define MODULE_IMPORT_NS/ { gsub(/__stringify$ns$/, "ns"); print; next; } /MODULE_IMPORT_NS/ { $0 = gensub(/MODULE_IMPORT_NS$([^)]*)$/, "MODULE_IMPORT_NS(\"\\1\")", "g"); } /EXPORT_SYMBOL_NS/ { if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)$([^,]+),/) { if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)$/ && $0 !~ /(EXPORT_SYMBOL_NS[^(]*)/ && $0 !~ /^my/) { getline line; gsub(/[[:space:]]*\\$/, ""); gsub(/[[:space:]]/, "", line); $0 = $0 " " line; } $0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)$([^,]+), ([^)]+)$/, "\\1(\\2, \"\\3\")", "g"); } } { print }' $file; done Requested-by: Masahiro Yamada Signed-off-by: Peter Zijlstra (Intel) Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc Acked-by: Greg KH Signed-off-by: Linus Torvalds

counter: interrupt-cnt: Implement watch_validate callback

2022-09-30T12:32:35Z

The interrupt-cnt counter driver only pushes one type of event on only one channel: COUNTER_EVENT_CHANGE_OF_STATE on channel 0. The interrupt_cnt_watch_validate() watch_valid callback is implemented to ensure watch configurations are valid for this driver. Cc: Oleksij Rempel Cc: Pengutronix Kernel Team Link: https://lore.kernel.org/r/20220815225058.144203-1-william.gray@linaro.org/ Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/r/c50b5eede7d3f523de8dc3937dc44680f2773e1d.1664318353.git.william.gray@linaro.org Signed-off-by: Greg Kroah-Hartman

counter: Move symbols into COUNTER namespace

2022-09-30T12:32:35Z

Counter subsystem symbols are only relevant to counter drivers. A COUNTER namespace is created to control the availability of these symbols to modules that import this namespace explicitly. Cc: Patrick Havelange Cc: Jarkko Nikula Cc: Oleksij Rempel Cc: Pengutronix Kernel Team Cc: Kamel Bouhara Cc: Fabrice Gasnier Cc: Maxime Coquelin Cc: Alexandre Torgue Acked-by: David Lechner Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/20220815220321.74161-1-william.gray@linaro.org/ Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/r/8a756df96c24946547a7ece5caa5f654809c5e7f.1664318353.git.william.gray@linaro.org Signed-off-by: Greg Kroah-Hartman

counter: interrupt-cnt: add counter_push_event()

2022-03-18T13:04:30Z

Add counter_push_event() to notify user space about new pulses Link: https://lore.kernel.org/r/20220203135727.2374052-3-o.rempel@pengutronix.de Signed-off-by: Oleksij Rempel Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/r/9da3460113b5092e8658e12f23578567aab7cc5f.1647373009.git.vilhelm.gray@gmail.com Signed-off-by: Greg Kroah-Hartman

counter: interrupt-cnt: Convert to new counter registration

2021-12-30T16:44:07Z

This fixes device lifetime issues where it was possible to free a live struct device. Fixes: a55ebd47f21f ("counter: add IRQ or GPIO based counter") Reviewed-by: Jonathan Cameron Acked-by: William Breathitt Gray Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20211230150300.72196-17-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

counter: interrupt-cnt: Convert to counter_priv() wrapper

2021-12-30T16:44:06Z

This is a straight forward conversion to the new counter_priv() wrapper. Acked-by: Jonathan Cameron Acked-by: William Breathitt Gray Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20211230150300.72196-7-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman