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path: root/drivers/mailbox/mailbox.c
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* mailbox: reset txdone_method TXDONE_BY_POLL if client knows_txdoneSudeep Holla2017-11-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 optionalBjorn Andersson2017-06-141-6/+10
| | | | | | | | 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_tickSudeep Holla2017-04-271-1/+4
| | | | | | | | | | | | 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>
* mailbox: skip complete wait event if timer expiredSudeep Holla2017-04-271-3/+3
| | | | | | | | | | | | | | | | | | If a wait_for_completion_timeout() call returns due to a timeout, complete() can get called after returning from the wait which is incorrect and can cause subsequent transmissions on a channel to fail. Since the wait_for_completion_timeout() sees the completion variable is non-zero caused by the erroneous/spurious complete() call, and it immediately returns without waiting for the time as expected by the client. This patch fixes the issue by skipping complete() call for the timer expiry. Fixes: 2b6d83e2b8b7 ("mailbox: Introduce framework for mailbox") Reported-by: 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: always wait in mbox_send_message for blocking Tx modeSudeep Holla2017-04-271-1/+1
| | | | | | | | | | | | | | | | There exists a race when msg_submit return immediately as there was an active request being processed which may have completed just before it's checked again in mbox_send_message. This will result in return to the caller without waiting in mbox_send_message even when it's blocking Tx. This patch fixes the issue by waiting for the completion always if Tx is in blocking mode. Fixes: 2b6d83e2b8b7 ("mailbox: Introduce framework for mailbox") Reported-by: Alexey Klimov <alexey.klimov@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Alexey Klimov <alexey.klimov@arm.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
* mailbox: check ->last_tx_done for NULL in case of timer-based pollingAlexey Klimov2017-03-281-0/+6
| | | | | | | | | | | | | | | It is allowed by code to register mailbox controller that sets txdone_poll flag to request timer-based polling with missed ->last_tx_done() method. If such thing happens and since presence of last_tx_done() is not checked it will fail in hrtimer callback function txdone_hrtimer() when first message will be transmitted. This patch adds check for this method and logging of error on registration of mailbox controller if it requested timer-based polling. Signed-off-by: Alexey Klimov <alexey.klimov@arm.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
* ktime: Cleanup ktime_set() usageThomas Gleixner2016-12-251-2/+1
| | | | | | | | | | ktime_set(S,N) was required for the timespec storage type and is still useful for situations where a Seconds and Nanoseconds part of a time value needs to be converted. For anything where the Seconds argument is 0, this is pointless and can be replaced with a simple assignment. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
* mailbox: Stop using ENOSYS for anything other than unimplemented syscallsLee Jones2016-04-121-2/+2
| | | | | | | | | | | In accordance with e15f431fe2d5 ("errno.h: Improve ENOSYS's comment") and 91c9afaf97ee ("checkpatch.pl: new instances of ENOSYS are errors") we're converting from the old meaning of: ENOSYS "Function not implemented" to a more standard EINVAL. Reported-by: Seraphin Bonnaffe <seraphin.bonnaffe@st.com> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
* mailbox: switch to hrtimer for tx_complete pollingSudeep Holla2015-08-101-12/+15
| | | | | | | | | | | | | | | | | The mailbox core uses jiffy based timer to handle polling for the transmit completion. If the client/protocol have/support notification of the last packet transmit completion via ACK packet, then we tick the Tx state machine immediately in the callback. However if the client doesn't support that mechanism we might end-up waiting for atleast a jiffy even though the remote is ready to receive the next request. This patch switches the timer used for that polling from jiffy-based to hrtimer-based so that we can support polling at much higher time resolution. Reported-and-suggested-by: Juri Lelli <Juri.Lelli@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
* mailbox: Add ability for clients to request channels by nameLee Jones2015-06-111-0/+29
| | | | | | | | | | | | This patch supplies a new framework API; mbox_request_channel_byname(). It works by supplying the usual client pointer as the first argument and a string as the second. The API will search the client's node for a 'mbox-names' property then request a channel in the normal way using the requested string's index as the expected second 'index' argument. Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
* mailbox: Fix up error handling in mbox_request_channel()Benson Leung2015-05-121-3/+8
| | | | | | | | | | | | | | | mbox_request_channel() currently returns EBUSY in the event the controller is not present or if of_xlate() fails, but in neither case is EBUSY really appropriate. Return EPROBE_DEFER if the controller is not yet present and change of_xlate() to return an ERR_PTR instead of NULL so that the error can be propagated back to the caller of mbox_request_channel(). Signed-off-by: Benson Leung <bleung@chromium.org> Signed-off-by: Andrew Bresticker <abrestic@chromium.org> Acked-by: Suman Anna <s-anna@ti.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
* mailbox: check for bit set before pollingJassi Brar2015-02-061-1/+1
| | | | | | | | Before polling we just need to see if the TXDONE_BY_POLL bit is set in txdone_method. There may be another bit (method) specified as well, like TXDONE_BY_ACK. Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
* Mailbox: Add support for Platform Communication ChannelAshwin Chaugule2014-11-271-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | ACPI 5.0+ spec defines a generic mode of communication between the OS and a platform such as the BMC. This medium (PCC) is typically used by CPPC (ACPI CPU Performance management), RAS (ACPI reliability protocol) and MPST (ACPI Memory power states). This patch adds PCC support as a Mailbox Controller. As of ACPI v5.1 there is no provision for clients to lookup mailbox controllers in a way that Linux expects. e.g. in DT the clients can list the mailboxes they can associate with in the DT binding and then provide a unique index to lookup a channel within a mailbox. Since the ACPI spec doesn't have anything similar, we introduce a mailbox controller specific API so that when the client calls it, we know to lookup in the context of a specific controller. This also helps in keeping a consistent interface across DT and ACPI for such drivers. This patch implements basic PCC support using the ACPI v5.1 structures. IRQ mode support will be provided as follow up patches. Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> Reviewed-by: Mark Brown <broonie@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
* mailbox: add tx_prepare client callbackSudeep Holla2014-11-271-0/+2
| | | | | | | | | | | | | | | | | | If the mailbox controller expects the payload is in place before initiating the transmit, then it's impossible to reuse the list maintained by core mailbox code currently. Maintaining another list for sending the message in the controller seems totally unnecessary as core mailbox library already provides that feature. This patch introduces tx_prepare callback in mbox_client which can be used by the core mailbox library before initiating the transaction through mbox->ops->send_data. The client driver can implement this callback to ensure the payload is copied to the shared memory. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
* mailbox: Don't unnecessarily re-arm the polling timerAndrew Bresticker2014-11-271-5/+8
| | | | | | | | | | | | | | | poll_txdone() will unconditionally re-arm the polling timer if there was an active request, even if the active request completed and no other requests were submitted. This is fixed by: - only re-arming the timer if the controller reported that the current transmission has not completed, and, - moving the call to poll_txdone() into msg_submit() so that the controller gets polled (and the timer re-armed, if necessary) whenever a new message is submitted. Signed-off-by: Andrew Bresticker <abrestic@chromium.org> Reviewed-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
* mailbox: Introduce framework for mailboxJassi Brar2014-10-081-0/+465
Introduce common framework for client/protocol drivers and controller drivers of Inter-Processor-Communication (IPC). Client driver developers should have a look at include/linux/mailbox_client.h to understand the part of the API exposed to client drivers. Similarly controller driver developers should have a look at include/linux/mailbox_controller.h Reviewed-by: Mark Brown <broonie@linaro.org> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
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