Commit Graph

109 Commits

Author SHA1 Message Date
Sudeep Holla a0edee6350 firmware: arm_scmi: Use NULL instead of integer 0 for rate pointer
Kbuild test robot reports the following sparse warning:

drivers/firmware/arm_scmi/clock.c:142:21:
	sparse: Using plain integer as NULL pointer

Use NULL pointer instead of integer 0 for rate pointer and fix the
warning.

Link: https://lore.kernel.org/r/20200717140405.17905-1-sudeep.holla@arm.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2020-07-17 16:06:54 +02:00
Cristian Marussi 72a5eb9d9c firmware: arm_scmi: Remove fixed size fields from reports/scmi_event_header
Event reports are used to convey information describing events to the
registered user-callbacks: they are necessarily derived from the underlying
raw SCMI events' messages but they are not meant to expose or directly
mirror any of those messages data layout, which belong to the protocol
layer.

Using fixed size types for report fields, mirroring messages structure,
is at odd with this: get rid of them using more generic, equivalent,
typing.

Substitute scmi_event_header fixed size fields with generic types too and
shuffle around fields definitions to minimize implicit padding while
adapting involved functions.

Link: https://lore.kernel.org/r/20200710133919.39792-3-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-13 09:40:21 +01:00
Cristian Marussi 33ee97f823 firmware: arm_scmi: Remove unneeded __packed attribute
Remove __packed attribute from struct scmi_event_header.

Link: https://lore.kernel.org/r/20200710133919.39792-2-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-13 09:40:21 +01:00
Sudeep Holla a4ee9d0194 firmware: arm_scmi: Provide a missing function param description
gcc as well as clang now produce warnings for missing kerneldoc function
parameter.

Fix the following W=1 kernel build warning:

drivers/firmware/arm_scmi/smc.c:32:
 warning: Function parameter or member 'shmem_lock' not described in 'scmi_smc'

Link: https://lore.kernel.org/r/20200709153155.22573-1-sudeep.holla@arm.com
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-13 09:40:21 +01:00
Sudeep Holla dccec73de9 firmware: arm_scmi: Keep the discrete clock rates sorted
Instead of relying on the firmware to keep the clock rates sorted, let
us sort the list. This is not essential for clock layer but it helps
to find the min and max rates easily from the list.

Link: https://lore.kernel.org/r/20200709081705.46084-1-sudeep.holla@arm.com
Fixes: 5f6c6430e9 ("firmware: arm_scmi: add initial support for clock protocol")
Reported-and-tested-by: Dien Pham <dien.pham.ry@renesas.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-10 12:06:27 +01:00
Cristian Marussi 585dfab3fb firmware: arm_scmi: Add base notifications support
Make SCMI base protocol register with the notification core.

Link: https://lore.kernel.org/r/20200701155348.52864-10-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-01 17:07:26 +01:00
Cristian Marussi 469ca1822d firmware: arm_scmi: Add reset notifications support
Make SCMI reset protocol register with the notification core.

Link: https://lore.kernel.org/r/20200701155348.52864-9-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-01 17:07:26 +01:00
Cristian Marussi 128e3e9311 firmware: arm_scmi: Add sensor notifications support
Make SCMI sensor protocol register with the notification core.

Link: https://lore.kernel.org/r/20200701155348.52864-8-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-01 17:07:26 +01:00
Cristian Marussi fb5086dc47 firmware: arm_scmi: Add perf notifications support
Make SCMI perf protocol register with the notification core.

Link: https://lore.kernel.org/r/20200701155348.52864-7-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-01 17:07:26 +01:00
Cristian Marussi e27077bc04 firmware: arm_scmi: Add power notifications support
Make SCMI power protocol register with the notification core.

Link: https://lore.kernel.org/r/20200701155348.52864-6-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-01 17:07:26 +01:00
Cristian Marussi 6b8a69131d firmware: arm_scmi: Enable notification core
Initialize and enable SCMI notifications core support during bus/driver
probe phase, so that protocols can start registering their supported
events during their initialization.

Link: https://lore.kernel.org/r/20200701155348.52864-5-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-01 17:07:26 +01:00
Cristian Marussi bd31b24969 firmware: arm_scmi: Add notification dispatch and delivery
Add the core SCMI notifications dispatch and delivery support logic
which is able to dispatch well-known received events from the Rx
interrupt handler to the dedicated deferred worker. From there, it will
deliver the events to the registered users' callbacks.

Dispatch and delivery support is just added here, still not enabled.

Link: https://lore.kernel.org/r/20200701155348.52864-4-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-01 17:07:25 +01:00
Cristian Marussi e7c215f358 firmware: arm_scmi: Add notification callbacks-registration
Add the core SCMI notifications callbacks-registration support: allow
users to register their own callbacks against the desired events.

Whenever a registration request is issued against a still non existent
event, mark such request as pending for later processing, in order to
account for possible late initializations of SCMI Protocols associated
to loadable drivers.

Link: https://lore.kernel.org/r/20200701155348.52864-3-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-01 17:07:25 +01:00
Cristian Marussi 1fc2dd1864 firmware: arm_scmi: Add notification protocol-registration
Add the core SCMI notifications protocol-registration support: allow
protocols to register their own set of supported events, during their
initialization phase. Notification core can track multiple platform
instances by their handles.

Link: https://lore.kernel.org/r/20200701155348.52864-2-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-07-01 17:07:25 +01:00
Cristian Marussi e0f1a30cf1 firmware: arm_scmi: Fix SCMI genpd domain probing
When, at probe time, an SCMI communication failure inhibits the capacity
to query power domains states, such domains should be skipped.

Registering partially initialized SCMI power domains with genpd will
causes kernel panic.

 arm-scmi timed out in resp(caller: scmi_power_state_get+0xa4/0xd0)
 scmi-power-domain scmi_dev.2: failed to get state for domain 9
 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
 Mem abort info:
   ESR = 0x96000006
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
 Data abort info:
   ISV = 0, ISS = 0x00000006
   CM = 0, WnR = 0
 user pgtable: 4k pages, 48-bit VAs, pgdp=00000009f3691000
 [0000000000000000] pgd=00000009f1ca0003, p4d=00000009f1ca0003, pud=00000009f35ea003, pmd=0000000000000000
 Internal error: Oops: 96000006 [#1] PREEMPT SMP
 CPU: 2 PID: 381 Comm: bash Not tainted 5.8.0-rc1-00011-gebd118c2cca8 #2
 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Jan  3 2020
 Internal error: Oops: 96000006 [#1] PREEMPT SMP
 pstate: 80000005 (Nzcv daif -PAN -UAO BTYPE=--)
 pc : of_genpd_add_provider_onecell+0x98/0x1f8
 lr : of_genpd_add_provider_onecell+0x48/0x1f8
 Call trace:
  of_genpd_add_provider_onecell+0x98/0x1f8
  scmi_pm_domain_probe+0x174/0x1e8
  scmi_dev_probe+0x90/0xe0
  really_probe+0xe4/0x448
  driver_probe_device+0xfc/0x168
  device_driver_attach+0x7c/0x88
  bind_store+0xe8/0x128
  drv_attr_store+0x2c/0x40
  sysfs_kf_write+0x4c/0x60
  kernfs_fop_write+0x114/0x230
  __vfs_write+0x24/0x50
  vfs_write+0xbc/0x1e0
  ksys_write+0x70/0xf8
  __arm64_sys_write+0x24/0x30
  el0_svc_common.constprop.3+0x94/0x160
  do_el0_svc+0x2c/0x98
  el0_sync_handler+0x148/0x1a8
  el0_sync+0x158/0x180

Do not register any power domain that failed to be queried with genpd.

Fixes: 898216c97e ("firmware: arm_scmi: add device power domain support using genpd")
Link: https://lore.kernel.org/r/20200619220330.12217-1-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-06-30 14:08:18 +01:00
Sudeep Holla d764282377 firmware: arm_scmi: Use HAVE_ARM_SMCCC_DISCOVERY instead of ARM_PSCI_FW
Commit e5bfb21d98 ("firmware: smccc: Add HAVE_ARM_SMCCC_DISCOVERY to
identify SMCCC v1.1 and above") introduced new config option to identify
the availability of SMCCC discoverability of version and features
transparently hiding the indirect dependency on ARM_PSCI_FW.

Commit 5a897e3ab4 ("firmware: arm_scmi: fix psci dependency") just
worked around the build dependency making SCMI SMC/HVC transport depend
on ARM_PSCI_FW at the time. Since it really just relies on SMCCC directly
and not on ARM_PSCI_FW, let us move to use CONFIG_HAVE_ARM_SMCCC_DISCOVERY
instead of CONFIG_ARM_PSCI_FW.

Link: https://lore.kernel.org/r/20200625101937.51939-1-sudeep.holla@arm.com
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-06-30 14:08:10 +01:00
Nicola Mazzucato 1909872ff2 firmware: arm_scmi: Add fast_switch_possible() interface
Add a new fast_switch_possible interface to the existing perf_ops to
export the information of whether or not fast_switch is possible for a
given device.

This can be used by the cpufreq driver and framework to choose proper
mechanism for frequency change.

Link: https://lore.kernel.org/r/20200617094332.8391-1-nicola.mazzucato@arm.com
Suggested-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Nicola Mazzucato <nicola.mazzucato@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-06-30 14:07:15 +01:00
Sudeep Holla bad0d73b65 firmware: arm_scmi: Use signed integer to report transfer status
Currently the trace event 'scmi_xfer_end' reports the status of the
transfer using the unsigned status field read from the firmware which
may not be easy to interpret. It may also miss to emit any timeouts
that happen in the driver resulting in emitting garbage in the status
field in those scenarios.

Let us use signed integer so that error values are emitted out after
they are mapped from firmware error formats to standard linux error
codes. While at this, also include any timeouts in the driver itself.

Link: https://lore.kernel.org/r/20200609134503.55860-1-sudeep.holla@arm.com
Cc: Jim Quinlan <james.quinlan@broadcom.com>
Cc: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-06-30 14:07:08 +01:00
Sudeep Holla 5a897e3ab4 firmware: arm_scmi: fix psci dependency
When CONFIG_ARM_PSCI_FW is disabled but CONFIG_HAVE_ARM_SMCCC is enabled,
arm-scmi runs into a link failure:

arm-linux-gnueabi-ld: drivers/firmware/arm_scmi/smc.o: in function `smc_send_message':
smc.c:(.text+0x200): undefined reference to `arm_smccc_1_1_get_conduit'

Change from HAVE_ARM_SMCCC to ARM_PSCI_FW config dependency for now.
We rely on PSCI bindings anyways for the conduit and this should be
fine.

Link: https://lore.kernel.org/r/20200507144905.11397-1-sudeep.holla@arm.com
Fixes: 1dc6558062 ("firmware: arm_scmi: Add smc/hvc transport")
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-05-07 16:28:56 +01:00
Sudeep Holla f7199cf489 firmware: arm_scmi: Fix return error code in smc_send_message
SMCCC can return NOT_SUPPORTED(-1). Map it to appropriate Linux error
codes namely -EOPNOTSUPP.

Link: https://lore.kernel.org/r/20200417103232.6896-1-sudeep.holla@arm.com
Reported-and-Tested-by:: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-20 17:57:34 +01:00
Cristian Marussi c5bceb98ce firmware: arm_scmi: Fix handling of unexpected delayed responses
Upon reception of an unexpected bogus delayed response, clear the channel
and bail-out safely.

Link: https://lore.kernel.org/r/20200420152315.21008-5-cristian.marussi@arm.com
Fixes: 4d09852b6f ("firmware: arm_scmi: Add support for notifications message processing")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-20 17:25:26 +01:00
Cristian Marussi d04fb2b2dd firmware: arm_scmi: Clear channel for delayed responses
Clear channel properly when done processing a delayed response.
This will let the platform firmware know that the channel is now free to
use it for any new delayed response or notification.

Link: https://lore.kernel.org/r/20200420152315.21008-4-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
(sudeep.holla: Updated commit log to reflect that channel is now free for
 platform to use)
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-20 17:25:26 +01:00
Cristian Marussi b37f5cc8d2 firmware: arm_scmi: Clear channel on reception of unexpected responses
When an unexpected response message is received we currently warn the user
and bail-out, ensure to also free the channel by invoking the transport
independent operation .clear_channel()

Link: https://lore.kernel.org/r/20200420152315.21008-3-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-20 17:25:26 +01:00
Cristian Marussi 87dff4e63c firmware: arm_scmi: Rename .clear_notification() transport_ops
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>
2020-04-20 17:25:26 +01:00
Sudeep Holla 4d09852b6f firmware: arm_scmi: Add support for notifications message processing
Add the mechanisms to distinguish notifications from delayed responses
and command responses. Also add support to properly fetch notification
messages upon reception. Notifications processing does not continue any
further after the fetch phase.

Link: https://lore.kernel.org/r/20200327143438.5382-5-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
[Reworked/renamed scmi_handle_xfer_delayed_resp()]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-14 09:31:49 +01:00
Cristian Marussi d5141f37c4 firmware: arm_scmi: Add notifications support in transport layer
Add common transport-layer methods to:
 - fetch a notification instead of a response
 - clear a pending notification

Add also all the needed support in mailbox/shmem transports.

Link: https://lore.kernel.org/r/20200327143438.5382-4-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-14 09:31:49 +01:00
Sudeep Holla 2264417a9a firmware: arm_scmi: Update protocol commands and notification list
Add commands' enumerations and messages definitions for all existing
notify-enable commands across all protocols.

Link: https://lore.kernel.org/r/20200327143438.5382-3-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-14 09:31:49 +01:00
Sudeep Holla 4ebd8f6dea firmware: arm_scmi: Add receive buffer support for notifications
With all the plumbing in place, let's just add the separate dedicated
receive buffers to handle notifications that can arrive asynchronously
from the platform firmware to OS.

Also add one check to see if the platform supports any receive channels
before allocating the receive buffers: since those buffers are optionally
supported though, the whole xfer initialization is also postponed to be
able to check for their existence in advance.

Link: https://lore.kernel.org/r/20200327143438.5382-2-cristian.marussi@arm.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
[Changed parameters in __scmi_xfer_info_init()]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-14 09:31:49 +01:00
Sudeep Holla 4e44590ee4 firmware: arm_scmi: Drop checking for shmem property in parent node
The scmi protocol core driver checks for the channel availability
before evaluating the shmem property. If the individual protocols
don't have separate channel assigned to them, the channel alloted
for the BASE protocol is reused automatically.

Therefore there is no need to check for the shmem property in the
parent node if it is absent in the child protocol node.

Link: https://lore.kernel.org/r/20200327163654.13389-5-sudeep.holla@arm.com
Tested-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-14 09:31:49 +01:00
Sudeep Holla 8aa6e12bbf firmware: arm_scmi: Check shmem property for channel availablity
Instead of declaring the channel availabilty unconditionally, let us
check for the presence of "shmem" property and return the channel
availablity accordingly.

Link: https://lore.kernel.org/r/20200327163654.13389-4-sudeep.holla@arm.com
Tested-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-14 09:31:48 +01:00
Sudeep Holla b9d15ee21c firmware: arm_scmi: Drop empty stub for smc_mark_txdone
The scmi protocol core driver check for non NULL mark_txdone before
invoking the same. There is no need to provide a empty stub. SMC/HVC
calls are synchronous and the call return indicates the completion.

Link: https://lore.kernel.org/r/20200327163654.13389-3-sudeep.holla@arm.com
Tested-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-14 09:31:48 +01:00
Sudeep Holla 18988265b8 firmware: arm_scmi: Make mutex channel specific
In order to support multiple SMC/HVC transport channels with associated
shared memory, it is better to maintain the mutex per channel instead of
existing global one.

Move the smc_mutex into the scmi_smc structure and also rename it to
shmem_lock which is more appropriate for it's use.

Link: https://lore.kernel.org/r/20200327163654.13389-2-sudeep.holla@arm.com
Tested-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-14 09:31:48 +01:00
Peng Fan 1dc6558062 firmware: arm_scmi: Add smc/hvc transport
Use the value of "arm,smc-id" property from the device tree as the first
argument for SMCCC call leaving all the other arguments as zero for now.

There is no Rx, only Tx because of smc/hvc not support Rx.

Link: https://lore.kernel.org/r/1583673879-20714-3-git-send-email-peng.fan@nxp.com
Signed-off-by: Peng Fan <peng.fan@nxp.com>
[sudeep.holla: reworded commit log/subject and fixed !HAVE_ARM_SMCCC build]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-04-14 09:31:48 +01:00
Gustavo A. R. Silva 8694548ae1 firmware: arm_scmi/perf: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Replace the zero-length member "opp" in scmi_msg_resp_perf_describe_levels
structure with flexible-array.

Link: https://lore.kernel.org/r/20200211231252.GA14830@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-02-20 17:12:24 +00:00
Gustavo A. R. Silva 4ddfb4af07 firmware: arm_scmi: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Replace the zero-length member "msg_payload" in scmi_shared_mem
structure with flexible-array.

Link: https://lore.kernel.org/r/20200211231045.GA13956@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
[ rebased the change as files are moved around ]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-02-20 17:11:28 +00:00
Viresh Kumar 5c8a47a5a9 firmware: arm_scmi: Make scmi core independent of the transport type
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>
2020-02-10 11:50:51 +00:00
Viresh Kumar c4eb83660a firmware: arm_scmi: Move macros and helpers to common.h
Move message header specific macros and helper routines to common.h as
they will be used outside of driver.c in a later commit.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/6615db480370719b0a0241447a5f3feb8eea421f.1580448239.git.viresh.kumar@linaro.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-02-10 11:50:47 +00:00
Viresh Kumar 71af05a7d0 firmware: arm_scmi: Update doc style comments
Fix minor formatting issues with the doc style comments.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/1bff7c0d1ad2c8b6eeff9660421f414f8c612eb2.1580448239.git.viresh.kumar@linaro.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2020-02-10 11:50:41 +00:00
Lukasz Luba 729d3530a5 drivers: firmware: scmi: Extend SCMI transport layer by trace events
The SCMI transport layer communicates via mailboxes and shared memory with
firmware running on a microcontroller. It is platform specific how long it
takes to pass a SCMI message. The most sensitive requests are coming from
CPUFreq subsystem, which might be used by the scheduler.
Thus, there is a need to measure these delays and capture anomalies.
This change introduces trace events wrapped around transfer code.

According to Jim's suggestion a unique transfer_id is to distinguish
similar entries which might have the same message id, protocol id and
sequence. This is a case then there are some timeouts in transfers.

Suggested-by: Jim Quinlan <james.quinlan@broadcom.com>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-30 12:34:37 +00:00
Sudeep Holla 2deb267b26 firmware: arm_scmi: Skip protocol initialisation for additional devices
The scmi bus now supports adding multiple devices per protocol,
and since scmi_protocol_init is called for each scmi device created,
we must avoid allocating protocol private data and initialising the
protocol itself if it is already initialised.

In order to achieve the same, we can simple replace the idr pointer
from protocol initialisation function to a dummy function.

Suggested-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-24 11:36:26 +00:00
Sudeep Holla b55b06b794 firmware: arm_scmi: Stash version in protocol init functions
In order to avoid querying the individual protocol versions multiple
time with more that one device created for each protocol, we can simple
store the copy in the protocol specific private data and use them whenever
required.

Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-24 11:35:49 +00:00
Sudeep Holla 50872a9463 firmware: arm_scmi: Match scmi device by both name and protocol id
The scmi bus now has support to match the driver with devices not only
based on their protocol id but also based on their device name if one is
available. This was added to cater the need to support multiple devices
and drivers for the same protocol.

Let us add the name "genpd" to scmi_device_id table in the driver so
that in matches only with device with the same name and protocol id
SCMI_PROTOCOL_POWER.

Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-24 11:35:49 +00:00
Sudeep Holla 4605e224db firmware: arm_scmi: Add versions and identifier attributes using dev_groups
Platform drivers now have the option to have the platform core create
and remove any needed sysfs attribute files. Using the same, let's add
the scmi firmware and protocol version attributes as well as vendor and
sub-vendor identifiers to sysfs.

It helps to identify the firmware details from the sysfs entries similar
to ARM SCPI implementation.

Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-24 11:35:49 +00:00
Sudeep Holla 9c5c463f2a firmware: arm_scmi: Add names to scmi devices created
Now that scmi bus provides option to create named scmi device, let us
create the default devices with names. This will help to add names for
matching to respective drivers and eventually to add multiple devices
and drivers per protocol.

Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-24 11:35:49 +00:00
Sudeep Holla 11040889af firmware: arm_scmi: Skip scmi mbox channel setup for addtional devices
Now that the scmi bus supports adding multiple devices per protocol,
and since scmi_create_protocol_device calls scmi_mbox_chan_setup,
we must avoid allocating and initialising the mbox channel if it is
already initialised.

Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-24 11:35:49 +00:00
Sudeep Holla ee7a9c9f67 firmware: arm_scmi: Add support for multiple device per protocol
Currently only one scmi device is created for each protocol enumerated.
However, there is requirement to make use of some procotols by multiple
kernel subsystems/frameworks. One such example is SCMI PERFORMANCE
protocol which can be used by both cpufreq and devfreq drivers.
Similarly, SENSOR protocol may be used by hwmon and iio subsystems,
and POWER protocol may be used by genpd and regulator drivers.

In order to achieve that, let us extend the scmi bus to match based
not only protocol id but also the scmi device name if one is available.

Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-12-24 11:35:48 +00:00
Wen Yang 8305e90a89 firmware: arm_scmi: Avoid double free in error flow
If device_register() fails, both put_device() and kfree() are called,
ending with a double free of the scmi_dev.

Calling kfree() is needed only when a failure happens between the
allocation of the scmi_dev and its registration, so move it to there
and remove it from the error flow.

Fixes: 46edb8d132 ("firmware: arm_scmi: provide the mandatory device release callback")
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-11-26 10:50:30 +00:00
Sudeep Holla 7bd39bc6bf firmware: arm_scmi: Fix doorbell ring logic for !CONFIG_64BIT
The logic to ring the scmi performance fastchannel ignores the
value read from the doorbell register in case of !CONFIG_64BIT.
This bug also shows up as warning with '-Wunused-but-set-variable' gcc
flag:

drivers/firmware/arm_scmi/perf.c: In function scmi_perf_fc_ring_db:
drivers/firmware/arm_scmi/perf.c:323:7: warning: variable val set but
			not used [-Wunused-but-set-variable]

Fix the same by aligning the logic with CONFIG_64BIT as used in the
macro SCMI_PERF_FC_RING_DB().

Fixes: 823839571d ("firmware: arm_scmi: Make use SCMI v2.0 fastchannel for performance protocol")
Reported-by: Hulk Robot <hulkci@huawei.com>
Reported-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-11-14 11:13:50 +00:00
Sudeep Holla 11ed5cf064 firmware: arm_scmi: reset: fix reset_state assignment in scmi_domain_reset
Fix the copy paste typo that incorrectly assigns domain_id with the
passed 'state' parameter instead of reset_state.

Fixes: 95a15d80aa ("firmware: arm_scmi: Add RESET protocol in SCMI v2.0")
Reported-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-09-18 13:42:16 +01:00
Sudeep Holla 95a15d80aa firmware: arm_scmi: Add RESET protocol in SCMI v2.0
SCMIv2.0 adds a new Reset Management Protocol to manage various reset
states a given device or domain can enter. Device(s) that can be
collectively reset through a common reset signal constitute a reset
domain for the firmware.

A reset domain can be reset autonomously or explicitly through assertion
and de-assertion of the signal. When autonomous reset is chosen, the
firmware is responsible for taking the necessary steps to reset the
domain and to subsequently bring it out of reset. When explicit reset is
chosen, the caller has to specifically assert and then de-assert the
reset signal by issuing two separate RESET commands.

Add the basic SCMI reset infrastructure that can be used by Linux
reset controller driver.

Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2019-08-12 12:23:02 +01:00