[ Upstream commit ad78b81a1077f7d956952cd8bdfe1e61504e3eb8 ]
A misbheaving SCMI platform firmware could reply with out-of-spec messages,
shorter than the mimimum size comprising a header and a status field.
Harden shmem_fetch_response to properly truncate such a bad messages.
Fixes: 5c8a47a5a9 ("firmware: arm_scmi: Make scmi core independent of the transport type")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221222183823.518856-3-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3f4071cbd2063b917486d1047a4da47718215fee ]
Platform drivers .remove callbacks are not supposed to fail and report
errors. Such errors are indeed ignored by the core platform drivers
and the driver unbind process is anyway completed.
The SCMI core platform driver as it is now, instead, bails out reporting
an error in case of an explicit unbind request.
Fix the removal path by adding proper device links between the core SCMI
device and the SCMI protocol devices so that a full SCMI stack unbind is
triggered when the core driver is removed. The remove process does not
bail out anymore on the anomalous conditions triggered by an explicit
unbind but the user is still warned.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221028140833.280091-1-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit be9ba1f7f9e0b565b19f4294f5871da9d654bc6d ]
SCMI Rx channels are optional and they can fail to be setup when not
present but anyway channels setup routines must bail-out on memory errors.
Make channels setup, and related probing, fail when memory errors are
reported on Rx channels.
Fixes: 5c8a47a5a9 ("firmware: arm_scmi: Make scmi core independent of the transport type")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221028140833.280091-4-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dea796fcab0a219830831c070b8dc367d7e0f708 ]
Currently, when removing the SCMI PM driver not all the resources
registered with genpd subsystem are properly de-registered.
As a side effect of this after a driver unload/load cycle you get a
splat with a few warnings like this:
| debugfs: Directory 'BIG_CPU0' with parent 'pm_genpd' already present!
| debugfs: Directory 'BIG_CPU1' with parent 'pm_genpd' already present!
| debugfs: Directory 'LITTLE_CPU0' with parent 'pm_genpd' already present!
| debugfs: Directory 'LITTLE_CPU1' with parent 'pm_genpd' already present!
| debugfs: Directory 'LITTLE_CPU2' with parent 'pm_genpd' already present!
| debugfs: Directory 'LITTLE_CPU3' with parent 'pm_genpd' already present!
| debugfs: Directory 'BIG_SSTOP' with parent 'pm_genpd' already present!
| debugfs: Directory 'LITTLE_SSTOP' with parent 'pm_genpd' already present!
| debugfs: Directory 'DBGSYS' with parent 'pm_genpd' already present!
| debugfs: Directory 'GPUTOP' with parent 'pm_genpd' already present!
Add a proper scmi_pm_domain_remove callback to the driver in order to
take care of all the needed cleanups not handled by devres framework.
Link: https://lore.kernel.org/r/20220817172731.1185305-7-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 76f89c954788763db575fb512a40bd483864f1e9 ]
Accessing sensor domains descriptors by the index upon the SCMI drivers
requests through the SCMI sensor operations interface can potentially
lead to out-of-bound violations if the SCMI driver misbehave.
Add an internal consistency check before any such domains descriptors
accesses.
Link: https://lore.kernel.org/r/20220817172731.1185305-4-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1ecb7d27b1af6705e9a4e94415b4d8cc8cf2fbfb ]
SCMI protocols abstract and expose a number of protocol specific
resources like clocks, sensors and so on. Information about such
specific domain resources are generally exposed via an `info_get`
protocol operation.
Improve the sanity check on these operations where needed.
Link: https://lore.kernel.org/r/20220817172731.1185305-3-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3c6656337852e9f1a4079d172f3fddfbf00868f9 upstream.
This reverts commit a3b884cef8 ("firmware: arm_scmi: Add clock management
to the SCMI power domain").
Using the GENPD_FLAG_PM_CLK tells genpd to gate/ungate the consumer
device's clock(s) during runtime suspend/resume through the PM clock API.
More precisely, in genpd_runtime_resume() the clock(s) for the consumer
device would become ungated prior to the driver-level ->runtime_resume()
callbacks gets invoked.
This behaviour isn't a good fit for all platforms/drivers. For example, a
driver may need to make some preparations of its device in its
->runtime_resume() callback, like calling clk_set_rate() before the
clock(s) should be ungated. In these cases, it's easier to let the clock(s)
to be managed solely by the driver, rather than at the PM domain level.
For these reasons, let's drop the use GENPD_FLAG_PM_CLK for the SCMI PM
domain, as to enable it to be more easily adopted across ARM platforms.
Fixes: a3b884cef8 ("firmware: arm_scmi: Add clock management to the SCMI power domain")
Cc: Nicolas Pitre <npitre@baylibre.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20220919122033.86126-1-ulf.hansson@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b75c83d9b961fd3abf7310f8d36d5e6e9f573efb ]
SCMI Reset protocol specification allows the asynchronous reset request
only when an autonomous reset action is specified. Reset requests based
on explicit assert/deassert of signals should not be served
asynchronously.
Current implementation will instead issue an asynchronous request in any
case, as long as the reset domain had advertised to support asynchronous
resets.
Avoid requesting the asynchronous resets when the reset action is not
of the autonomous type, even if the target reset domain does, in general,
support the asynchronous requests.
Link: https://lore.kernel.org/r/20220817172731.1185305-6-cristian.marussi@arm.com
Fixes: 95a15d80aa ("firmware: arm_scmi: Add RESET protocol in SCMI v2.0")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e9076ffbcaed5da6c182b144ef9f6e24554af268 ]
Accessing reset domains descriptors by the index upon the SCMI drivers
requests through the SCMI reset operations interface can potentially
lead to out-of-bound violations if the SCMI driver misbehave.
Add an internal consistency check before any such domains descriptors
accesses.
Link: https://lore.kernel.org/r/20220817172731.1185305-5-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Stable-dep-of: b75c83d9b961 ("firmware: arm_scmi: Fix the asynchronous reset requests")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8009120e0354a67068e920eb10dce532391361d0 ]
While enumerating protocols implemented by the SCMI platform using
BASE_DISCOVER_LIST_PROTOCOLS, the number of returned protocols is
currently validated in an improper way since the check employs a sum
between unsigned integers that could overflow and cause the check itself
to be silently bypassed if the returned value 'loop_num_ret' is big
enough.
Fix the validation avoiding the addition.
Link: https://lore.kernel.org/r/20220330150551.2573938-4-cristian.marussi@arm.com
Fixes: b6f20ff8bd ("firmware: arm_scmi: add common infrastructure and support for base protocol")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 23274739a5b6166f74d8d9cb5243d7bf6b46aab9 ]
During SCMI Clock protocol initialization, after having retrieved from the
SCMI platform all the available discrete rates for a specific clock, the
clock rates array is sorted, unfortunately using a pointer to its end as
a base instead of its start, so that sorting does not work.
Fix invocation of sort() passing as base a pointer to the start of the
retrieved clock rates array.
Link: https://lore.kernel.org/r/20220318092813.49283-1-cristian.marussi@arm.com
Fixes: dccec73de9 ("firmware: arm_scmi: Keep the discrete clock rates sorted")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 98f0d68f94ea21541e0050cc64fa108ade779839 ]
On SCMI transports whose channels are based on a shared resource the TX
channel area has to be acquired by the agent before placing the desired
command into the channel and it will be then relinquished by the platform
once the related reply has been made available into the channel.
On an RX channel the logic is reversed with the platform acquiring the
channel area and the agent reliquishing it once done by calling the
scmi_clear_channel() helper.
As a consequence, even in case of error, the agent must never try to clear
a TX channel from its side: restrict the existing clear channel call on the
the reply path only to delayed responses since they are indeed coming from
the RX channel.
Link: https://lore.kernel.org/r/20220224152404.12877-1-cristian.marussi@arm.com
Fixes: e9b21c9618 ("firmware: arm_scmi: Make .clear_channel optional")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d1cbd9e0f7e51ae8e3638a36ba884fdbb2fc967e ]
According to scmi specification, the response of the discover agent request
is made of:
- int32 status
- uint32 agent_id
- uint8 name[16]
but the current implementation doesn't take into account the agent_id field
and only allocates a rx buffer of SCMI_MAX_STR_SIZE length
Allocate the correct length for rx buffer and copy the name from the
correct offset in the response.
While no error were returned until v5.15, v5.16-rc1 fails with virtio_scmi
transport channel:
| arm-scmi firmware:scmi0: SCMI Notifications - Core Enabled.
| arm-scmi firmware:scmi0: SCMI Protocol v2.0 'Linaro:PMWG' Firmware version 0x2090000
| scmi-virtio virtio0: tx:used len 28 is larger than in buflen 24
Link: https://lore.kernel.org/r/20211117081856.9932-1-vincent.guittot@linaro.org
Fixes: b6f20ff8bd ("firmware: arm_scmi: add common infrastructure and support for base protocol")
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 95161165727650a707bc34ecfac286a418b6bb00 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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>
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>
ARM_SCMI_TRANSPORT_VIRTIO is a 'bool' Kconfig used to include support for
the SCMI virtio transport inside the core SCMI stack; a bare transport
dependency attached here to this option, though, cannot be properly
propagated to the parent ARM_SCMI_PROTOCOL option and, as a result, it is
currently possible to configure a Kernel where SCMI core is builtin
and includes support for virtio while VirtIO core is =m.
This allowed combination breaks linking:
ARM_SCMI_PROTOCOL=y
ARM_SCMI_TRANSPORT_VIRTIO=y
VIRTIO=m
Bind the dependency in ARM_SCMI_TRANSPORT_VIRTIO to the chosen kind of
compilation of ARM_SCMI_PROTOCOL.
Link: https://lore.kernel.org/r/20210816141609.41751-1-cristian.marussi@arm.com
Fixes: 46abe13b5e ("firmware: arm_scmi: Add virtio transport")
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Arnd Bergmann <arnd@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Pull ARM SoC driver updates from Arnd Bergmann:
"These are updates for drivers that are tied to a particular SoC,
including the correspondig device tree bindings:
- A couple of reset controller changes for unisoc, uniphier, renesas
and zte platforms
- memory controller driver fixes for omap and tegra
- Rockchip io domain driver updates
- Lots of updates for qualcomm platforms, mostly touching their
firmware and power management drivers
- Tegra FUSE and firmware driver updateѕ
- Support for virtio transports in the SCMI firmware framework
- cleanup of ixp4xx drivers, towards enabling multiplatform support
and bringing it up to date with modern platforms
- Minor updates for keystone, mediatek, omap, renesas"
* tag 'drivers-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (96 commits)
reset: simple: remove ZTE details in Kconfig help
soc: rockchip: io-domain: Remove unneeded semicolon
soc: rockchip: io-domain: add rk3568 support
dt-bindings: power: add rk3568-pmu-io-domain support
bus: ixp4xx: return on error in ixp4xx_exp_probe()
soc: renesas: Prefer memcpy() over strcpy()
firmware: tegra: Stop using seq_get_buf()
soc/tegra: fuse: Enable fuse clock on suspend for Tegra124
soc/tegra: fuse: Add runtime PM support
soc/tegra: fuse: Clear fuse->clk on driver probe failure
soc/tegra: pmc: Prevent racing with cpuilde driver
soc/tegra: bpmp: Remove unused including <linux/version.h>
dt-bindings: soc: ti: pruss: Add dma-coherent property
soc: ti: Remove pm_runtime_irq_safe() usage for smartreflex
soc: ti: pruss: Enable support for ICSSG subsystems on K3 AM64x SoCs
dt-bindings: soc: ti: pruss: Update bindings for K3 AM64x SoCs
firmware: arm_scmi: Use WARN_ON() to check configured transports
firmware: arm_scmi: Fix boolconv.cocci warnings
soc: mediatek: mmsys: Fix missing UFOE component in mt8173 table routing
soc: mediatek: mmsys: add MT8365 support
...
Use a WARN_ON() when SCMI stack is loaded to check the consistency of
configured SCMI transports instead of the current compile-time check
BUILD_BUG_ON() to avoid breaking bot-builds on random bad configs.
Bail-out early and noisy during SCMI stack initialization if no transport
was enabled in configuration since SCMI cannot work without at least one
enabled transport and such constraint cannot be enforced in Kconfig due to
circular dependency issues.
Link: https://lore.kernel.org/r/20210809092245.8730-1-cristian.marussi@arm.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
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>
Mailbox channels for the base protocol are setup during probe.
There can be a scenario where probe fails to acquire the base
protocol due to a timeout leading to cleaning up of all device
managed memory including the scmi_mailbox structure setup during
mailbox_chan_setup function.
| arm-scmi soc:qcom,scmi: timed out in resp(caller: version_get+0x84/0x140)
| arm-scmi soc:qcom,scmi: unable to communicate with SCMI
| arm-scmi: probe of soc:qcom,scmi failed with error -110
Now when a message arrives at cpu slightly after the timeout, the mailbox
controller will try to call the rx_callback of the client and might end
up accessing freed memory.
| rx_callback+0x24/0x160
| mbox_chan_received_data+0x44/0x94
| __handle_irq_event_percpu+0xd4/0x240
This patch frees the mailbox channels setup during probe and adds some more
error handling in case the probe fails.
Link: https://lore.kernel.org/r/1628111999-21595-1-git-send-email-rishabhb@codeaurora.org
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
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>
Add a new opaque void *priv parameter to scmi_rx_callback which can be
optionally provided by the transport layer when invoking scmi_rx_callback
and that will be passed back to the transport layer in xfer->priv.
This can be used by transports that needs to keep track of their specific
data structures together with the valid xfers.
Link: https://lore.kernel.org/r/20210803131024.40280-15-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Some transports are also effectively registered with other kernel subsystem
in order to be properly probed and initialized; as a consequence such kind
of transports, and their related devices, might still not have been probed
and initialized at the time the main SCMI core driver is probed.
Add an optional .link_supplier() transport operation which can be used by
the core SCMI stack to dynamically check if the transport is ready and
dynamically link its device to the SCMI platform instance device.
Link: https://lore.kernel.org/r/20210803131024.40280-13-cristian.marussi@arm.com
Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
[ Cristian: reworded commit message ]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Add abstractions for future transports using message passing, such as
virtio. Derive the abstractions from the shared memory abstractions.
Abstract the transport SDU through the opaque struct scmi_msg_payld.
Also enable the transport to determine all other required information
about the transport SDU.
Link: https://lore.kernel.org/r/20210803131024.40280-12-cristian.marussi@arm.com
Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
[ Cristian: Adapted to new SCMI Kconfig layout, updated Copyrights ]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
The maximum number of simultaneously pending messages is a transport
specific quantity that is usually described statically in struct scmi_desc.
Some transports, though, can calculate such number only at run-time after
some initial transport specific setup and probing is completed; moreover
the resulting max message numbers could also be different between rx and
tx channels.
Add an optional get_max_msg() operation so that a transport can report more
accurate max message numbers for each channel type.
The value in scmi_desc.max_msg is still used as default when transport does
not provide any get_max_msg() method.
Link: https://lore.kernel.org/r/20210803131024.40280-11-cristian.marussi@arm.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: refactored how get_max_msg() is used to minimize core changes ]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Add configuration options to be able to select which SCMI transports have
to be compiled into the SCMI stack.
Mailbox and SMC are by default enabled if their related dependencies are
satisfied.
While doing that move all SCMI related config options in their own
dedicated submenu.
Link: https://lore.kernel.org/r/20210803131024.40280-9-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Even though in case of asynchronous commands an SCMI platform is
constrained to emit the delayed response message only after the related
message response has been sent, the configured underlying transport could
still deliver such messages together or in inverted order, causing races
due to the concurrent or out-of-order access to the underlying xfer.
Introduce a mechanism to grant exclusive access to an xfer in order to
properly serialize concurrent accesses to the same xfer originating from
multiple correlated messages.
Add additional state information to xfer descriptors so as to be able to
identify out-of-order message deliveries and act accordingly:
- when a delayed response is expected but delivered before the related
response, the synchronous response is considered as successfully
received and the delayed response processing is carried on as usual.
- when/if the missing synchronous response is subsequently received, it
is discarded as not congruent with the current state of the xfer, or
simply, because the xfer has been already released and so, now, the
monotonically increasing sequence number carried by the late response
is stale.
Link: https://lore.kernel.org/r/20210803131024.40280-6-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Tokens are sequence numbers embedded in the each SCMI message header: they
are used to correlate commands with responses (and delayed responses), but
their usage and policy of selection is entirely up to the caller (usually
the OSPM agent), while they are completely opaque to the callee (i.e. SCMI
platform) which merely copies them back from the command into the response
message header.
This also means that the platform does not, can not and should not enforce
any kind of policy on received messages depending on the contained sequence
number: platform can perfectly handle concurrent requests carrying the same
identifiying token if that should happen.
Moreover the platform is not required to produce in-order responses to
agent requests, the only constraint in these regards is that in case of
an asynchronous message the delayed response must be sent after the
immediate response for the synchronous part of the command transaction.
Currenly the SCMI stack of the OSPM agent selects a token for the egressing
commands picking the lowest possible number which is not already in use by
an existing in-flight transaction, which means, in other words, that we
immediately reuse any token after its transaction has completed or it has
timed out: this policy indeed does simplify management and lookup of tokens
and associated xfers.
Under the above assumptions and constraints, since there is really no state
shared between the agent and the platform to let the platform know when a
token and its associated message has timed out, the current policy of early
reuse of tokens can easily lead to the situation in which a spurious or
late received response (or delayed_response), related to an old stale and
timed out transaction, can be wrongly associated to a newer valid in-flight
xfer that just happens to have reused the same token.
This misbehaviour on such late/spurious responses is more easily exposed on
those transports that naturally have an higher level of parallelism in
processing multiple concurrent in-flight messages.
This commit introduces a new policy of selection of tokens for the OSPM
agent: each new command transfer now gets the next available, monotonically
increasing token, until tokens are exhausted and the counter rolls over.
Such new policy mitigates the above issues with late/spurious responses
since the tokens are now reused as late as possible (when they roll back
ideally) and so it is much easier to identify such late/spurious responses
to stale timed out transactions: this also helps in simplifying the
specific transports implementation since stale transport messages can be
easily identified and discarded early on in the rx path without the need
to cross check their actual state with the core transport layer.
This mitigation is even more effective when, as is usually the case, the
maximum number of pending messages is capped by the platform to a much
lower number than the whole possible range of tokens values (2^10).
This internal policy change in the core SCMI transport layer is fully
transparent to the specific transports so it has not and should not have
any impact on the transports implementation.
Link: https://lore.kernel.org/r/20210803131024.40280-5-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Some SCMI transport could need to perform some transport specific setup
before they can be used by the SCMI core transport layer: typically this
early setup consists in registering with some other kernel subsystem.
Add the optional capability for a transport to provide a couple of init
and exit functions that are assured to be called early during the SCMI
core initialization phase, well before the SCMI core probing step.
[ Peter: Adapted RFC patch by Cristian for submission to upstream. ]
Link: https://lore.kernel.org/r/20210803131024.40280-4-cristian.marussi@arm.com
Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
[ Cristian: Fixed scmi_transports_exit point of invocation ]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
SCMI message headers carry a sequence number and such field is sized to
allow for MSG_TOKEN_MAX distinct numbers; moreover zero is not really an
acceptable maximum number of pending in-flight messages.
Fix accordingly the checks performed on the value exported by transports
in scmi_desc.max_msg
Link: https://lore.kernel.org/r/20210712141833.6628-3-cristian.marussi@arm.com
Reported-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
[sudeep.holla: updated the patch title and error message]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
scmi_resp_sensor_reading_complete structure is meant to represent an
SCMI asynchronous reading complete message. The readings field with
a 64bit type forces padding and breaks reads in scmi_sensor_reading_get.
Split it in two adjacent 32bit readings_low/high subfields to avoid the
padding within the structure. Alternatively we could to mark the structure
packed.
Link: https://lore.kernel.org/r/20210628170042.34105-1-cristian.marussi@arm.com
Fixes: e2083d3673 ("firmware: arm_scmi: Add SCMI v3.0 sensors timestamped reads")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Kernel doc validation script still complains about the following:
|No description found for return value of 'scmi_get_protocol_device'
|No description found for return value of 'scmi_devm_notifier_register'
|No description found for return value of 'scmi_devm_notifier_unregister'
Fix adding missing Return kernel-doc statements.
Link: https://lore.kernel.org/r/20210712143504.33541-1-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
The scmi_linux_errmap buffer access index is supposed to depend on the
array size to prevent element out of bounds access. It uses SCMI_ERR_MAX
to check bounds but that can mismatch with the array size. It also
changes the success into -EIO though scmi_linux_errmap is never used in
case of success, it is expected to work for success case too.
It is slightly confusing code as the negative of the error code
is used as index to the buffer. Fix it by negating it at the start and
make it more readable.
Link: https://lore.kernel.org/r/20210707135028.1869642-1-sudeep.holla@arm.com
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
