Pull EFI fixes from Ard Biesheuvel:

 - A pair of tweaks to the EFI random seed code so that externally
   provided version of this config table are handled more robustly

 - Another fix for the v6.0 EFI variable refactor that turned out to
   break Apple machines which don't provide QueryVariableInfo()

 - Add some guard rails to the EFI runtime service call wrapper so we
   can recover from synchronous exceptions caused by firmware

* tag 'efi-fixes-for-v6.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  arm64: efi: Recover from synchronous exceptions occurring in firmware
  efi: efivars: Fix variable writes with unsupported query_variable_store()
  efi: random: Use 'ACPI reclaim' memory for random seed
  efi: random: reduce seed size to 32 bytes
  efi/tpm: Pass correct address to memblock_reserve

Arm SCMI fixes for v6.1

A bunch of fixes to handle:
1. A possible resource leak in scmi_remove(). The returned error
   value gets ignored by the driver core and can remove the device and
   free the devm-allocated resources. As a simple solution to be able to
   easily backport, the bind attributes in the driver is suppressed as
   there is no need to support it. Additionally the remove path is cleaned
   up by adding device links between the core and the protocol devices
   so that a proper and complete unbinding happens.
2. A possible spin-loop in the SCMI transmit path in case of misbehaving
   platform firmware. A timeout is added to the existing loop so that
   the SCMI stack can bailout aborting the transmission with warnings.
3. Optional Rx channel correctly by reporting any memory errors instead
   of ignoring the same with other allowed errors.
4. The use of proper device for all the device managed allocations in the
   virtio transport.
5. Incorrect deferred_tx_wq release on the error paths by using devres
   API(devm_add_action_or_reset) to manage the release in the error path.

* tag 'scmi-fixes-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  firmware: arm_scmi: Fix deferred_tx_wq release on error paths
  firmware: arm_scmi: Fix devres allocation device in virtio transport
  firmware: arm_scmi: Make Rx chan_setup fail on memory errors
  firmware: arm_scmi: Make tx_prepare time out eventually
  firmware: arm_scmi: Suppress the driver's bind attributes
  firmware: arm_scmi: Cleanup the core driver removal callback

Link: https://lore.kernel.org/r/20221102140142.2758107-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Use devres to allocate the dedicated deferred_tx_wq polling workqueue so
as to automatically trigger the proper resource release on error path.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 5a3b7185c47c ("firmware: arm_scmi: Add atomic mode support to virtio transport")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221028140833.280091-6-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

SCMI virtio transport device managed allocations must use the main
platform device in devres operations instead of the channel devices.

Cc: Peter Hilber <peter.hilber@opensynergy.com>
Fixes: 46abe13b5e3d ("firmware: arm_scmi: Add virtio transport")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221028140833.280091-5-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

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: 5c8a47a5a91d ("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>

SCMI transports based on shared memory, at start of transmissions, have
to wait for the shared Tx channel area to be eventually freed by the
SCMI platform before accessing the channel. In fact the channel is owned
by the SCMI platform until marked as free by the platform itself and,
as such, cannot be used by the agent until relinquished.

As a consequence a badly misbehaving SCMI platform firmware could lock
the channel indefinitely and make the kernel side SCMI stack loop
forever waiting for such channel to be freed, possibly hanging the
whole boot sequence.

Add a timeout to the existent Tx waiting spin-loop so that, when the
system ends up in this situation, the SCMI stack can at least bail-out,
nosily warn the user, and abort the transmission.

Reported-by: YaxiongTian <iambestgod@outlook.com>
Suggested-by: YaxiongTian <iambestgod@outlook.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Etienne Carriere <etienne.carriere@linaro.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221028140833.280091-3-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Suppress the capability to unbind the core SCMI driver since all the
SCMI stack protocol drivers depend on it.

Fixes: aa4f886f3893 ("firmware: arm_scmi: add basic driver infrastructure for SCMI")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221028140833.280091-2-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

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>

Commit 8a254d90a775 ("efi: efivars: Fix variable writes without
query_variable_store()") addressed an issue that was introduced during
the EFI variable store refactor, where alternative implementations of
the efivars layer that lacked query_variable_store() would no longer
work.

Unfortunately, there is another case to consider here, which was missed:
if the efivars layer is backed by the EFI runtime services as usual, but
the EFI implementation predates the introduction of QueryVariableInfo(),
we will return EFI_UNSUPPORTED, and this is no longer being dealt with
correctly.

So let's fix this, and while at it, clean up the code a bit, by merging
the check_var_size() routines as well as their callers.

Cc: <stable@vger.kernel.org> # v6.0
Fixes: bbc6d2c6ef22 ("efi: vars: Switch to new wrapper layer")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Aditya Garg <gargaditya08@live.com>

EFI runtime services data is guaranteed to be preserved by the OS,
making it a suitable candidate for the EFI random seed table, which may
be passed to kexec kernels as well (after refreshing the seed), and so
we need to ensure that the memory is preserved without support from the
OS itself.

However, runtime services data is intended for allocations that are
relevant to the implementations of the runtime services themselves, and
so they are unmapped from the kernel linear map, and mapped into the EFI
page tables that are active while runtime service invocations are in
progress. None of this is needed for the RNG seed.

So let's switch to EFI 'ACPI reclaim' memory: in spite of the name,
there is nothing exclusively ACPI about it, it is simply a type of
allocation that carries firmware provided data which may or may not be
relevant to the OS, and it is left up to the OS to decide whether to
reclaim it after having consumed its contents.

Given that in Linux, we never reclaim these allocations, it is a good
choice for the EFI RNG seed, as the allocation is guaranteed to survive
kexec reboots.

One additional reason for changing this now is to align it with the
upcoming recommendation for EFI bootloader provided RNG seeds, which
must not use EFI runtime services code/data allocations.

Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>