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path: root/drivers/mailbox/mailbox.c
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2019-08-04mailbox: handle failed named mailbox channel requestmorten petersen1-2/+4
[ Upstream commit 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2017-08-07mailbox: handle empty message in tx_tickSudeep Holla1-1/+4
commit cb710ab1d8a23f68ff8f45aedf3e552bb90e70de upstream. 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> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-07mailbox: skip complete wait event if timer expiredSudeep Holla1-3/+3
commit cc6eeaa3029a6dbcb4ad41b1f92876483bd88965 upstream. 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> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-07mailbox: always wait in mbox_send_message for blocking Tx modeSudeep Holla1-1/+1
commit c61b781ee084e69855477d23dd33e7e6caad652c upstream. 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> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12mailbox: Stop using ENOSYS for anything other than unimplemented syscallsLee Jones1-2/+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>
2015-08-10mailbox: switch to hrtimer for tx_complete pollingSudeep Holla1-12/+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>
2015-06-11mailbox: Add ability for clients to request channels by nameLee Jones1-0/+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>
2015-05-12mailbox: Fix up error handling in mbox_request_channel()Benson Leung1-3/+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>
2015-02-06mailbox: check for bit set before pollingJassi Brar1-1/+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>
2014-11-27Mailbox: Add support for Platform Communication ChannelAshwin Chaugule1-3/+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>
2014-11-27mailbox: add tx_prepare client callbackSudeep Holla1-0/+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>
2014-11-27mailbox: Don't unnecessarily re-arm the polling timerAndrew Bresticker1-5/+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>
2014-10-08mailbox: Introduce framework for mailboxJassi Brar1-0/+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>