commit 2ab4f4018cb6b8010ca5002c3bdc37783b5d28c2 upstream.
When mailboxes are used as a transport it is possible to setup the SCMI
transport layer, depending on the underlying channels configuration, to use
one or two mailboxes, associated, respectively, to one or two, distinct,
shared memory areas: any other combination should be treated as invalid.
Add more strict checking of SCMI mailbox transport device node descriptors.
Fixes: 5c8a47a5a9 ("firmware: arm_scmi: Make scmi core independent of the transport type")
Cc: <stable@vger.kernel.org> # 4.19
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20230307162324.891866-1-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
scmi_mailbox is obtained from cinfo->transport_info and the first
call to mailbox_chan_free frees the channel and sets cinfo->transport_info
to NULL. Care is taken to check for non NULL smbox->chan but smbox can
itself be NULL. Fix it by checking for it without which, kernel crashes
with below NULL pointer dereference and eventually kernel panic.
Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000038
Modules linked in: scmi_module(-)
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno
Development Platform, BIOS EDK II Sep 2 2020
pstate: 80000005 (Nzcv daif -PAN -UAO BTYPE=--)
pc : mailbox_chan_free+0x2c/0x70 [scmi_module]
lr : idr_for_each+0x6c/0xf8
Call trace:
mailbox_chan_free+0x2c/0x70 [scmi_module]
idr_for_each+0x6c/0xf8
scmi_remove+0xa8/0xf0 [scmi_module]
platform_drv_remove+0x34/0x58
device_release_driver_internal+0x118/0x1f0
driver_detach+0x58/0xe8
bus_remove_driver+0x64/0xe0
driver_unregister+0x38/0x68
platform_driver_unregister+0x1c/0x28
scmi_driver_exit+0x38/0x44 [scmi_module]
---[ end trace 17bde19f50436de9 ]---
Kernel panic - not syncing: Fatal exception
SMP: stopping secondary CPUs
Kernel Offset: 0x1d0000 from 0xffff800010000000
PHYS_OFFSET: 0x80000000
CPU features: 0x0240022,25806004
Memory Limit: none
---[ end Kernel panic - not syncing: Fatal exception ]---
Link: https://lore.kernel.org/r/20200908112611.31515-1-sudeep.holla@arm.com
Fixes: 5c8a47a5a9 ("firmware: arm_scmi: Make scmi core independent of the transport type")
Cc: Cristian Marussi <cristian.marussi@arm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
SCMI transport operation .clear_notification() is indeed a generic method
to clear the channel in a transport dependent way, as such it could be a
useful helper also in other contexts.
Rename such method as .clear_channel(), renaming accordingly also its
already existent call-sites.
No functional change.
Link: https://lore.kernel.org/r/20200420152315.21008-2-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
The SCMI specification is fairly independent of the transport protocol,
which can be a simple mailbox (already implemented) or anything else.
The current Linux implementation however is very much dependent on the
mailbox transport layer.
This patch makes the SCMI core code (driver.c) independent of the
mailbox transport layer and moves all mailbox related code to a new
file: mailbox.c and all struct shared_mem related code to a new file:
shmem.c.
We can now implement more transport protocols to transport SCMI
messages.
The transport protocols just need to provide struct scmi_transport_ops,
with its version of the callbacks to enable exchange of SCMI messages.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/8698a3cec199b8feab35c2339f02dc232bfd773b.1580448239.git.viresh.kumar@linaro.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
