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[2620:137:e000::1:20]) by mx.google.com with ESMTP id a15-20020a170902eccf00b0017f7faef235si21728635plh.148.2022.10.19.13.49.40; Wed, 19 Oct 2022 13:50:08 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=arm.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231241AbiJSUqp (ORCPT + 99 others); Wed, 19 Oct 2022 16:46:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229982AbiJSUqn (ORCPT ); Wed, 19 Oct 2022 16:46:43 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 441EC1BBEC3 for ; Wed, 19 Oct 2022 13:46:42 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EC4641424; Wed, 19 Oct 2022 13:46:47 -0700 (PDT) Received: from e120937-lin.home (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 993753F792; Wed, 19 Oct 2022 13:46:39 -0700 (PDT) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: sudeep.holla@arm.com, james.quinlan@broadcom.com, Jonathan.Cameron@Huawei.com, f.fainelli@gmail.com, etienne.carriere@linaro.org, vincent.guittot@linaro.org, souvik.chakravarty@arm.com, wleavitt@marvell.com, peter.hilber@opensynergy.com, nicola.mazzucato@arm.com, tarek.el-sherbiny@arm.com, quic_kshivnan@quicinc.com, cristian.marussi@arm.com Subject: [PATCH v4 0/11] Introduce a unified API for SCMI Server testing Date: Wed, 19 Oct 2022 21:46:15 +0100 Message-Id: <20221019204626.3813043-1-cristian.marussi@arm.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW, SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1747150551811563744?= X-GMAIL-MSGID: =?utf-8?q?1747150551811563744?= Hi all, This series aims to introduce a new SCMI unified userspace interface meant to ease testing an SCMI Server implementation for compliance, fuzzing etc., from the perspective of the OSPM agent (non-secure world only ...) It is proposed as a testing/development facility, it is NOT meant to be a feature to use in production, but only enabled in Kconfig for test deployments. Currently an SCMI Compliance Suite like the one at [1] can only work by injecting SCMI messages at the SCMI transport layer using the mailbox test driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at the related replies from the SCMI backend Server. This approach has a few drawbacks: - the SCMI Server under test MUST be reachable through a mailbox based SCMI transport: any other SCMI Server placement is not possible (like in a VM reachable via SCMI Virtio). In order to cover other placements in the current scenario we should write some sort of test driver for each and every existent SCMI transport and for any future additional transport ...this clearly does not scale. - even in the mailbox case the userspace Compliance suite cannot simply send and receive bare SCMI messages BUT it has to properly lay them out into the shared memory exposed by the mailbox test driver as expected by the transport definitions. In other words such a userspace test application has to, not only use a proper transport driver for the system at hand, but it also has to have a comprehensive knowledge of the internals of the underlying transport in order to operate. - last but not least, the system under test has to be specifically configured and built, in terms of Kconfig and DT, to perform such kind of testing, it cannot be used for anything else, which is unfortunate for CI/CD deployments. This series introduces a new SCMI Raw mode support feature that, when configured and enabled exposes a new interface in debugfs through which: - a userspace application can inject bare SCMI binary messages into the SCMI core stack; such messages will be routed by the SCMI regular kernel stack to the backend Server using the currently configured transport transparently: in other words you can test the SCMI server, no matter where it is placed, as long as it is reachable from the currently configured SCMI stack. Same goes the other way around on the reading path: any SCMI server reply can be read as a bare SCMI binary message from the same debugfs path. - as a direct consequence of this way of injecting bare messages in the middle of the SCMI stack (instead of beneath it at the transport layer) the user application has to handle only bare SCMI messages without having to worry about the specific underlying transport internals that will be taken care of by the SCMI core stack itself using its own machinery, without duplicating such logic. - a system under test, once configured with SCMI Raw support enabled in Kconfig, can be booted without any particular DT change. In V2 the runtime enable/disable switching capability has been removed (for now) since still not deemed to be stable/reliable enough: as a consequence when SCMI Raw support is compiled in, the regular SCMI stack drivers are now inhibited permanently for that Kernel. In V4 it has been added the support for transports lacking a completion_irq or configured forcibly in polled mode. A quick and trivial example from the shell...reading from a sensor injecting a properly crafted packet in raw mode: # INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian) root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message # READING BACK THE REPLY... root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/message | od --endian=little -t x4 0000000 00005406 00000000 00000335 00000000 0000020 while doing that, since Raw mode makes (partial) use of the regular SCMI stack, you can observe the messages going through the SCMI stack with the usual traces: bash-329 [000] ..... 14183.446808: scmi_msg_dump: pt=15 t=CMND msg_id=06 seq=0000 s=0 pyld=0100000000000000 irq/35-mhu_db_l-81 [000] ..... 14183.447809: scmi_msg_dump: pt=15 t=RESP msg_id=06 seq=0000 s=0 pyld=3503000000000000 ..trying to read in async when the backend server does NOT supports asyncs: # AN ASYNC SENSOR READING REQUEST... root@deb-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x01\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message_async bash-329 [000] ..... 16415.938739: scmi_msg_dump: pt=15 t=CMND msg_id=06 seq=0000 s=0 pyld=0100000001000000 irq/35-mhu_db_l-81 [000] ..... 16415.944129: scmi_msg_dump: pt=15 t=RESP msg_id=06 seq=0000 s=-1 pyld= # RETURNS A STATUS -1 FROM THE SERVER NOT SUPPORTING IT root@deb-buster-arm64:~# cat /sys/kernel/debug/scmi_raw/message | od --endian=little -t x4 0000000 00005406 ffffffff 0000010 Note that this was on a JUNO, BUT exactly the same steps can be used to reach an SCMI Server living on a VM reachable via virtio as long as the system under test if properly configured to work with a virtio transport. In a nutshell the exposed API is as follows: /sys/kernel/debug/scmi_raw/ ├── errors ├── message ├── message_async ├── notification ├── reset ├── transport_max_msg_size ├── transport_rx_timeout_ms └── transport_tx_max_msg where: - message*: used to send sync/async commands and read back immediate and delayed responses (if any) - errors: used to report timeout and unexpected replies - reset: used to reset the SCMI Raw stack, flushing all queues from received messages still pending to be read out (useful to be sure to cleanup between test suite runs...) - notification: used to read any notification being spit by the system (if previously enabled by the user app) - transport*: a bunch of configuration useful to setup the user application expectations in terms of timeouts and message characteristics. Each write corresponds to one command request and the replies or delayed response are read back one message at time (receiving an EOF at each message boundary). The user application running the test is in charge of handling timeouts and properly choosing SCMI sequence numbers for the outgoing requests: note that the same fixed number can be re-used (...though discouraged...) as long as the suite does NOT expect to send multiple in-flight commands concurrently. Since the SCMI core regular stack is partially used to deliver and collect the messages, late replies after timeouts and any other sort of unexpected message sent by the SCMI server platform back can be identified by the SCMI core as usual and it will be reported under /errors for later analysis. (a userspace test-app will have anyway properly detected the timeout on /message* ...) All of the above has been roughly tested against a standard JUNO SCP SCMI Server (mailbox trans) and an emulated SCMI Server living in a VM (virtio trans) using a custom experimental version of the scmi-tests Compliance suite patched to support Raw mode and posted at [2]. (still in development ...merge requests are in progress...for now it is just a mean for me to test the testing API ... O_o) The series is based on v6.1-rc1. Having said that (in such a concise and brief way :P) ... ...any feedback/comments are welcome ! Thanks, Cristian Tested-by: Vincent Guittot Signed-off-by: Cristian Marussi --- V3 --> v4 - rebased on v6.1-rc1 - addedd missing support for 'polled' transports and transport lacking a completion_irq (like smc/optee) - removed a few inlines - refactored SCMI Raw RX patch to make use more extensively of the regular non-Raw RX path - fix handling of O_NONBLOCK raw_mode read requests v2 --> v3 - fixed some sparse warning on LE and __poll_t - reworked and simplified deferred worker in charge of xfer delayed waiting - allow for injection of DT-unknown protocols messages when in Raw mode (needed for any kind of fuzzing...) v1 --> v2 - added comments and debugfs docs - added dedicated transport devices for channels initialization - better channels handling in Raw mode - removed runtime enable, moved to static compile time exclusion of SCMI regular stack [1]: https://gitlab.arm.com/tests/scmi-tests [2]: https://gitlab.arm.com/tests/scmi-tests/-/commits/raw_mode_support_devel/ Cristian Marussi (11): firmware: arm_scmi: Refactor xfer in-flight registration routines firmware: arm_scmi: Simplify chan_available transport operation firmware: arm_scmi: Use dedicated devices to initialize channels firmware: arm_scmi: Refactor polling helpers firmware: arm_scmi: Refactor scmi_wait_for_message_response firmware: arm_scmi: Add xfer raw helpers firmware: arm_scmi: Move errors defs and code to common.h firmware: arm_scmi: Add raw transmission support firmware: arm_scmi: Add debugfs ABI documentation for Raw mode firmware: arm_scmi: Reject SCMI drivers while in Raw mode firmware: arm_scmi: Call Raw mode hooks from the core stack Documentation/ABI/testing/debugfs-scmi-raw | 88 ++ drivers/firmware/arm_scmi/Kconfig | 13 + drivers/firmware/arm_scmi/Makefile | 1 + drivers/firmware/arm_scmi/common.h | 72 +- drivers/firmware/arm_scmi/driver.c | 521 +++++--- drivers/firmware/arm_scmi/mailbox.c | 4 +- drivers/firmware/arm_scmi/optee.c | 4 +- drivers/firmware/arm_scmi/raw_mode.c | 1244 ++++++++++++++++++++ drivers/firmware/arm_scmi/raw_mode.h | 29 + drivers/firmware/arm_scmi/smc.c | 4 +- drivers/firmware/arm_scmi/virtio.c | 2 +- 11 files changed, 1827 insertions(+), 155 deletions(-) create mode 100644 Documentation/ABI/testing/debugfs-scmi-raw create mode 100644 drivers/firmware/arm_scmi/raw_mode.c create mode 100644 drivers/firmware/arm_scmi/raw_mode.h