linux.git/drivers/mailbox/mailbox.c, branch v5.12 Linux kernel source tree mailbox: avoid timer start from callback 2020-10-17T00:09:17+00:00 Jassi Brar jaswinder.singh@linaro.org 2020-10-16T17:20:56+00:00 c7dacf5b0f32957b24ef29df1207dc2cd8307743 If the txdone is done by polling, it is possible for msg_submit() to start the timer while txdone_hrtimer() callback is running. If the timer needs recheduling, it could already be enqueued by the time hrtimer_forward_now() is called, leading hrtimer to loudly complain. WARNING: CPU: 3 PID: 74 at kernel/time/hrtimer.c:932 hrtimer_forward+0xc4/0x110 CPU: 3 PID: 74 Comm: kworker/u8:1 Not tainted 5.9.0-rc2-00236-gd3520067d01c-dirty #5 Hardware name: Libre Computer AML-S805X-AC (DT) Workqueue: events_freezable_power_ thermal_zone_device_check pstate: 20000085 (nzCv daIf -PAN -UAO BTYPE=--) pc : hrtimer_forward+0xc4/0x110 lr : txdone_hrtimer+0xf8/0x118 [...] This can be fixed by not starting the timer from the callback path. Which requires the timer reloading as long as any message is queued on the channel, and not just when current tx is not done yet. Fixes: 0cc67945ea59 ("mailbox: switch to hrtimer for tx_complete polling") Reported-by: Da Xue <da@libre.computer> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Jerome Brunet <jbrunet@baylibre.com> Tested-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> 
If the txdone is done by polling, it is possible for msg_submit() to start
the timer while txdone_hrtimer() callback is running. If the timer needs
recheduling, it could already be enqueued by the time hrtimer_forward_now()
is called, leading hrtimer to loudly complain.

WARNING: CPU: 3 PID: 74 at kernel/time/hrtimer.c:932 hrtimer_forward+0xc4/0x110
CPU: 3 PID: 74 Comm: kworker/u8:1 Not tainted 5.9.0-rc2-00236-gd3520067d01c-dirty #5
Hardware name: Libre Computer AML-S805X-AC (DT)
Workqueue: events_freezable_power_ thermal_zone_device_check
pstate: 20000085 (nzCv daIf -PAN -UAO BTYPE=--)
pc : hrtimer_forward+0xc4/0x110
lr : txdone_hrtimer+0xf8/0x118
[...]

This can be fixed by not starting the timer from the callback path. Which
requires the timer reloading as long as any message is queued on the
channel, and not just when current tx is not done yet.

Fixes: 0cc67945ea59 ("mailbox: switch to hrtimer for tx_complete polling")
Reported-by: Da Xue <da@libre.computer>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Tested-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
mailbox: handle failed named mailbox channel request 2019-07-11T15:19:00+00:00 morten petersen morten_bp@live.dk 2019-07-08T11:41:54+00:00 25777e5784a7b417967460d4fcf9660d05a0c320 Previously, if mbox_request_channel_byname was used with a name which did not exist in the "mbox-names" property of a mailbox client, the mailbox corresponding to the last entry in the "mbox-names" list would be incorrectly selected. With this patch, -EINVAL is returned if the named mailbox is not found. Signed-off-by: Morten Borup Petersen <morten_bp@live.dk> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> 
Previously, if mbox_request_channel_byname was used with a name
which did not exist in the "mbox-names" property of a mailbox
client, the mailbox corresponding to the last entry in the
"mbox-names" list would be incorrectly selected.
With this patch, -EINVAL is returned if the named mailbox is
not found.

Signed-off-by: Morten Borup Petersen <morten_bp@live.dk>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19T15:09:55+00:00 Thomas Gleixner tglx@linutronix.de 2019-06-04T08:11:33+00:00 d2912cb15bdda8ba4a5dd73396ad62641af2f520 Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mailbox: Export mbox_flush() 2019-02-18T16:39:17+00:00 Thierry Reding treding@nvidia.com 2019-02-04T14:07:06+00:00 4f0557795e76d049f0a1687f1f050addf4df2dac The mbox_flush() function can be used by drivers that are built as modules, so the function needs to be exported. Reported-by: Mark Brown <broonie@kernel.org> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> 
The mbox_flush() function can be used by drivers that are built as
modules, so the function needs to be exported.

Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
mailbox: Allow multiple controllers per device 2018-12-22T04:31:26+00:00 Mikko Perttunen mperttunen@nvidia.com 2018-11-28T09:54:11+00:00 8ed82e23875e6014d9aa8e03bf4301b27d614050 Look through the whole controller list when mapping device tree phandles to controllers instead of stopping at the first one. Each controller is intended to only contain one kind of mailbox, but some devices (like Tegra HSP) implement multiple kinds and use the same device tree node for all of them. As such, we need to allow multiple mbox_controllers per device tree node. Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> 
Look through the whole controller list when mapping device tree
phandles to controllers instead of stopping at the first one.

Each controller is intended to only contain one kind of mailbox,
but some devices (like Tegra HSP) implement multiple kinds and use
the same device tree node for all of them. As such, we need to allow
multiple mbox_controllers per device tree node.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
mailbox: Support blocking transfers in atomic context 2018-12-22T04:31:26+00:00 Thierry Reding treding@nvidia.com 2018-11-28T09:54:10+00:00 a8803d7421cc2be2ac12a8155e5d824f04259eff The mailbox framework supports blocking transfers via completions for clients that can sleep. In order to support blocking transfers in cases where the transmission is not permitted to sleep, add a new ->flush() callback that controller drivers can implement to busy loop until the transmission has been completed. A new mbox_flush() function can be called by mailbox consumers in atomic context to make sure a transfer has completed. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> 
The mailbox framework supports blocking transfers via completions for
clients that can sleep. In order to support blocking transfers in cases
where the transmission is not permitted to sleep, add a new ->flush()
callback that controller drivers can implement to busy loop until the
transmission has been completed. A new mbox_flush() function can be
called by mailbox consumers in atomic context to make sure a transfer
has completed.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
mailbox: Add device-managed registration functions 2018-12-21T22:49:25+00:00 Thierry Reding treding@nvidia.com 2018-12-20T17:19:44+00:00 e898d9cdd3a9f105863d63dd3b46443742a4757c Add device-managed equivalents of the mbox_controller_register() and mbox_controller_unregister() functions that can be used to have the devres infrastructure automatically unregister mailbox controllers on driver probe failure or driver removal. This can help remove a lot of boiler plate code from drivers. Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> 
Add device-managed equivalents of the mbox_controller_register() and
mbox_controller_unregister() functions that can be used to have the
devres infrastructure automatically unregister mailbox controllers on
driver probe failure or driver removal. This can help remove a lot of
boiler plate code from drivers.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
mailbox: reset txdone_method TXDONE_BY_POLL if client knows_txdone 2017-11-14T14:51:28+00:00 Sudeep Holla sudeep.holla@arm.com 2017-09-28T10:18:52+00:00 33cd7123ac0ba5360656ae27db453de5b9aa711f Currently the mailbox framework sets txdone_method to TXDONE_BY_POLL if the controller sets txdone_by_poll. However some clients can have a mechanism to do TXDONE_BY_ACK which they can specify by knows_txdone. However, we endup setting both TXDONE_BY_POLL and TXDONE_BY_ACK in that case. In such scenario, we may end up with below warnings as the tx ticker is run both by mailbox framework and the client. WARNING: CPU: 1 PID: 0 at kernel/time/hrtimer.c:805 hrtimer_forward+0x88/0xd8 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.12.0-rc5 #242 Hardware name: ARM LTD ARM Juno Development Platform task: ffff8009768ca700 task.stack: ffff8009768f8000 PC is at hrtimer_forward+0x88/0xd8 LR is at txdone_hrtimer+0xd4/0xf8 Call trace: hrtimer_forward+0x88/0xd8 __hrtimer_run_queues+0xe4/0x158 hrtimer_interrupt+0xa4/0x220 arch_timer_handler_phys+0x30/0x40 handle_percpu_devid_irq+0x78/0x130 generic_handle_irq+0x24/0x38 __handle_domain_irq+0x5c/0xb8 gic_handle_irq+0x54/0xa8 This patch fixes the issue by resetting TXDONE_BY_POLL if client has set knows_txdone. Cc: Alexey Klimov <alexey.klimov@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> 
Currently the mailbox framework sets txdone_method to TXDONE_BY_POLL if
the controller sets txdone_by_poll. However some clients can have a
mechanism to do TXDONE_BY_ACK which they can specify by knows_txdone.
However, we endup setting both TXDONE_BY_POLL and TXDONE_BY_ACK in that
case. In such scenario, we may end up with below warnings as the tx
ticker is run both by mailbox framework and the client.

WARNING: CPU: 1 PID: 0 at kernel/time/hrtimer.c:805 hrtimer_forward+0x88/0xd8
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.12.0-rc5 #242
Hardware name: ARM LTD ARM Juno Development Platform
task: ffff8009768ca700 task.stack: ffff8009768f8000
PC is at hrtimer_forward+0x88/0xd8
LR is at txdone_hrtimer+0xd4/0xf8
Call trace:
 hrtimer_forward+0x88/0xd8
 __hrtimer_run_queues+0xe4/0x158
 hrtimer_interrupt+0xa4/0x220
 arch_timer_handler_phys+0x30/0x40
 handle_percpu_devid_irq+0x78/0x130
 generic_handle_irq+0x24/0x38
 __handle_domain_irq+0x5c/0xb8
 gic_handle_irq+0x54/0xa8

This patch fixes the issue by resetting TXDONE_BY_POLL if client has set
knows_txdone.

Cc: Alexey Klimov <alexey.klimov@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
mailbox: Make startup and shutdown ops optional 2017-06-14T12:17:09+00:00 Bjorn Andersson bjorn.andersson@linaro.org 2017-05-27T23:14:02+00:00 b7133d6fcd9a9eb4633357d4a27430d4e0c794ad Some mailbox hardware doesn't have to perform any additional operations on startup of shutdown, so make these optional. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> 
Some mailbox hardware doesn't have to perform any additional operations
on startup of shutdown, so make these optional.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
mailbox: handle empty message in tx_tick 2017-04-27T10:50:04+00:00 Sudeep Holla sudeep.holla@arm.com 2017-03-21T11:30:16+00:00 cb710ab1d8a23f68ff8f45aedf3e552bb90e70de We already check if the message is empty before calling the client tx_done callback. Calling completion on a wait event is also invalid if the message is empty. This patch moves the existing empty message check earlier. Fixes: 2b6d83e2b8b7 ("mailbox: Introduce framework for mailbox") Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org> 
We already check if the message is empty before calling the client
tx_done callback. Calling completion on a wait event is also invalid
if the message is empty.

This patch moves the existing empty message check earlier.

Fixes: 2b6d83e2b8b7 ("mailbox: Introduce framework for mailbox")
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>