Add support for .mark_txdone and .poll_done transport operations to SCMI
VirtIO transport as pre-requisites to enable atomic operations.
Add a Kernel configuration option to enable SCMI VirtIO transport polling
and atomic mode for selected SCMI transactions while leaving it default
disabled.
Link: https://lore.kernel.org/r/20220217131234.50328-4-cristian.marussi@arm.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Igor Skalkin <igor.skalkin@opensynergy.com>
Cc: Peter Hilber <peter.hilber@opensynergy.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Add a new spinlock dedicated to the access of the TX free list and a couple
of helpers to get and put messages back and forth from the free_list.
Link: https://lore.kernel.org/r/20220217131234.50328-3-cristian.marussi@arm.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Igor Skalkin <igor.skalkin@opensynergy.com>
Cc: Peter Hilber <peter.hilber@opensynergy.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Currently SCMI VirtIO channels are marked with a ready flag and related
lock to track channel lifetime and support proper synchronization at
shutdown when virtqueues have to be stopped.
This leads to some extended spinlocked sections with IRQs off on the RX
path to keep hold of the ready flag and does not scale well especially when
SCMI VirtIO polling mode will be introduced.
Add an SCMI VirtIO channel dedicated refcount to track active users on both
the TX and the RX path and properly enforce synchronization and cleanup at
shutdown, inhibiting further usage of the channel once freed.
Link: https://lore.kernel.org/r/20220217131234.50328-2-cristian.marussi@arm.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Igor Skalkin <igor.skalkin@opensynergy.com>
Cc: Peter Hilber <peter.hilber@opensynergy.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Couple of main additions:
- Support for OPTEE based SCMI transport to enable using SCMI service
provided by OPTEE on some platforms
- Support for atomic SCMI transports which enables few SCMI transactions
to be completed in atomic context. This involves other refactoring work
associated with it. It also marks SMC and OPTEE as atomic transport as
the commands are completed once the return
Other changes involves some trace and log enhancements and a miscellaneous
bug fix.
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Merge tag 'scmi-updates-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into for-next/scmi
Arm SCMI firmware interface updates for v5.17
Couple of main additions:
- Support for OPTEE based SCMI transport to enable using SCMI service
provided by OPTEE on some platforms
- Support for atomic SCMI transports which enables few SCMI transactions
to be completed in atomic context. This involves other refactoring work
associated with it. It also marks SMC and OPTEE as atomic transport as
the commands are completed once the return
Other changes involves some trace and log enhancements and a miscellaneous
bug fix.
* tag 'scmi-updates-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
firmware: arm_scmi: Add new parameter to mark_txdone
firmware: arm_scmi: Add atomic mode support to smc transport
firmware: arm_scmi: Add support for atomic transports
firmware: arm_scmi: Make optee support sync_cmds_completed_on_ret
firmware: arm_scmi: Make smc support sync_cmds_completed_on_ret
firmware: arm_scmi: Add sync_cmds_completed_on_ret transport flag
firmware: arm_scmi: Make smc transport use common completions
firmware: arm_scmi: Add configurable polling mode for transports
firmware: arm_scmi: Use new trace event scmi_xfer_response_wait
include: trace: Add new scmi_xfer_response_wait event
firmware: arm_scmi: Refactor message response path
firmware: arm_scmi: Set polling timeout to max_rx_timeout_ms
firmware: arm_scmi: Perform earlier cinfo lookup call in do_xfer
firmware: arm_scmi: optee: Drop the support for the OPTEE shared dynamic buffer
firmware: arm_scmi: optee: Fix missing mutex_init()
firmware: arm_scmi: Make virtio Version_1 compliance optional
firmware: arm_scmi: Add optee transport
dt-bindings: arm: Add OP-TEE transport for SCMI
firmware: arm_scmi: Review some virtio log messages
This will enable cleanups down the road.
The idea is to disable cbs, then add "flush_queued_cbs" callback
as a parameter, this way drivers can flush any work
queued after callbacks have been disabled.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Introduce a compilation option to disable strict enforcement of compliance
against VirtIO Version_1 backends, so as to allow to support also Legacy
VirtIO devices implementations.
Link: https://lore.kernel.org/r/20211115102910.7639-1-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Be more verbose avoiding to use _once flavour of dev_info/_err/_notice.
Remove usage of __func_ to identify which vqueue is referred in some error
messages and explicitly name the TX/RX vqueue.
Link: https://lore.kernel.org/r/20210916103336.7243-1-cristian.marussi@arm.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
During channel setup a failure in the call of scmi_vio_feed_vq_rx() leads
to an attempt to access a dev pointer by dereferencing vioch->cinfo at
a time when vioch->cinfo has still to be initialized.
Fix it by providing the device reference directly to scmi_vio_feed_vq_rx.
Link: https://lore.kernel.org/r/20211112180705.41601-1-cristian.marussi@arm.com
Fixes: 46abe13b5e ("firmware: arm_scmi: Add virtio transport")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Only one single SCMI Virtio device is currently supported by this driver
and it is referenced using a static global variable which is initialized
once for all during probing and nullified at virtio device removal.
Add proper SMP barriers to protect accesses to such device reference to
ensure that the initialzation state of such device is correctly observed by
all PEs at any time.
Return -EBUSY, instead of -EINVAL, and a descriptive error message if more
than one SCMI Virtio device is ever found and probed.
Link: https://lore.kernel.org/r/20210916103336.7243-3-cristian.marussi@arm.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Remove unneeded nested irqsave/irqrestore spinlocks.
Add also a few descriptive comments to explain better the system behaviour
at shutdown time.
Link: https://lore.kernel.org/r/20210916103336.7243-2-cristian.marussi@arm.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
virtio_scmi_exit() is only called from __exit function, so the annotation
is correct, but when the driver is built-in, the section gets discarded
and the reference from a callback pointer causes a link-time error:
`virtio_scmi_exit' referenced in section `.rodata' of drivers/firmware/arm_scmi/virtio.o:
defined in discarded section `.exit.text' of drivers/firmware/arm_scmi/virtio.o
I could not figure out a better workaround, so let's just remove that
annotation even if it wastes a couple of bytes in .text.
Link: https://lore.kernel.org/r/20210920100301.1466486-2-arnd@kernel.org
Fixes: 46abe13b5e ("firmware: arm_scmi: Add virtio transport")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
drivers/firmware/arm_scmi/virtio.c:225:40-45: WARNING: conversion to bool not needed here
Remove unneeded conversion to bool
Semantic patch information:
Relational and logical operators evaluate to bool,
explicit conversion is overly verbose and unneeded.
Generated by: scripts/coccinelle/misc/boolconv.cocci
Link: https://lore.kernel.org/r/20210807173127.GA43248@a24dbc127934
CC: Igor Skalkin <igor.skalkin@opensynergy.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
This transport enables communications with an SCMI platform through virtio;
the SCMI platform will be represented by a virtio device.
Implement an SCMI virtio driver according to the virtio SCMI device spec
[1]. Virtio device id 32 has been reserved for the SCMI device [2].
The virtio transport has one Tx channel (virtio cmdq, A2P channel) and
at most one Rx channel (virtio eventq, P2A channel).
The following feature bit defined in [1] is not implemented:
VIRTIO_SCMI_F_SHARED_MEMORY.
The number of messages which can be pending simultaneously is restricted
according to the virtqueue capacity negotiated at probing time.
As soon as Rx channel message buffers are allocated or have been read
out by the arm-scmi driver, feed them back to the virtio device.
Since some virtio devices may not have the short response time exhibited
by SCMI platforms using other transports, set a generous response
timeout.
SCMI polling mode is not supported by this virtio transport since deemed
meaningless: polling mode operation is offered by the SCMI core to those
transports that could not provide a completion interrupt on the TX path,
which is never the case for virtio whose core callbacks can easily call
into core scmi_rx_callback upon messages reception.
[1] https://github.com/oasis-tcs/virtio-spec/blob/master/virtio-scmi.tex
[2] https://www.oasis-open.org/committees/ballot.php?id=3496
Link: https://lore.kernel.org/r/20210803131024.40280-16-cristian.marussi@arm.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Co-developed-by: Peter Hilber <peter.hilber@opensynergy.com>
Co-developed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Igor Skalkin <igor.skalkin@opensynergy.com>
[ Peter: Adapted patch for submission to upstream. ]
Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
[ Cristian: simplified driver logic, changed link_supplier and channel
available/setup logic, removed dummy callbacks ]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
