kernel.git/drivers/thunderbolt/tb.h, branch linux-5.0.y

thunderbolt: Take domain lock in switch sysfs attribute callbacks

2019-05-31T13:45:04Z

[ Upstream commit 09f11b6c99feaf86a26444bca85dc693b3f58f8b ] switch_lock was introduced because it allowed serialization of device authorization requests from userspace without need to take the big domain lock (tb->lock). This was fine because device authorization with ICM is just one command that is sent to the firmware. Now that we start to handle all tunneling in the driver switch_lock is not enough because we need to walk over the topology to establish paths. For this reason drop switch_lock from the driver completely in favour of big domain lock. There is one complication, though. If userspace is waiting for the lock in tb_switch_set_authorized(), it keeps the device_del() from removing the sysfs attribute because it waits for active users to release the attribute first which leads into following splat: INFO: task kworker/u8:3:73 blocked for more than 61 seconds. Tainted: G W 5.1.0-rc1+ #244 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u8:3 D12976 73 2 0x80000000 Workqueue: thunderbolt0 tb_handle_hotplug [thunderbolt] Call Trace: ? __schedule+0x2e5/0x740 ? _raw_spin_lock_irqsave+0x12/0x40 ? prepare_to_wait_event+0xc5/0x160 schedule+0x2d/0x80 __kernfs_remove.part.17+0x183/0x1f0 ? finish_wait+0x80/0x80 kernfs_remove_by_name_ns+0x4a/0x90 remove_files.isra.1+0x2b/0x60 sysfs_remove_group+0x38/0x80 sysfs_remove_groups+0x24/0x40 device_remove_attrs+0x3d/0x70 device_del+0x14c/0x360 device_unregister+0x15/0x50 tb_switch_remove+0x9e/0x1d0 [thunderbolt] tb_handle_hotplug+0x119/0x5a0 [thunderbolt] ? process_one_work+0x1b7/0x420 process_one_work+0x1b7/0x420 worker_thread+0x37/0x380 ? _raw_spin_unlock_irqrestore+0xf/0x30 ? process_one_work+0x420/0x420 kthread+0x118/0x130 ? kthread_create_on_node+0x60/0x60 ret_from_fork+0x35/0x40 We deal this by following what network stack did for some of their attributes and use mutex_trylock() with restart_syscall(). This makes userspace release the attribute allowing sysfs attribute removal to progress before the write is restarted and eventually fail when the attribute is removed. Signed-off-by: Mika Westerberg Signed-off-by: Sasha Levin

thunderbolt: Add Intel as copyright holder

2018-10-02T22:52:08Z

Intel has done pretty major changes to the driver and we continue to do so in the future as well. Add Intel as copyright holder of the files we have done changes. While there drop "Cactus Ridge" from the headers because this driver works also with other Thunderbolt controllers. No functional changes intended. Signed-off-by: Mika Westerberg Acked-by: Yehezkel Bernat Signed-off-by: Greg Kroah-Hartman

thunderbolt: Make the driver less verbose

2018-10-02T22:52:08Z

Currently the driver logs quite a lot to the system message buffer even when doing normal operations. This information is not useful for ordinary users and might even annoy some. For this reason convert most of the logs at info level to happen at debug level instead. The nice output formatting is untouched. Logging can be easily re-enabled by passing "thunderbolt.dyndbg" in the kernel command line (or using the corresponding control file runtime). Signed-off-by: Mika Westerberg Acked-by: Yehezkel Bernat Signed-off-by: Greg Kroah-Hartman

thunderbolt: Add support for runtime PM

2018-07-25T08:55:29Z

When Thunderbolt host controller is set to RTD3 mode (Runtime D3) it is present all the time. Because of this it is important to runtime suspend the controller whenever possible. In case of ICM we have following rules which all needs to be true before the host controller can be put to D3: - The controller firmware reports to support RTD3 - All the connected devices announce support for RTD3 - There is no active XDomain connection Implement this using standard Linux runtime PM APIs so that when all the children devices are runtime suspended, the Thunderbolt host controller PCI device is runtime suspended as well. The ICM firmware then starts powering down power domains towards RTD3 but it can prevent this if it detects that there is an active Display Port stream (this is not visible to the software, though). The Thunderbolt host controller will be runtime resumed either when there is a remote wake event (device is connected or disconnected), or when there is access from userspace that requires hardware access. Signed-off-by: Mika Westerberg Signed-off-by: Greg Kroah-Hartman

thunderbolt: Add support for preboot ACL

2018-03-09T09:54:11Z

Preboot ACL is a mechanism that allows connecting Thunderbolt devices boot time in more secure way than the legacy Thunderbolt boot support. As with the legacy boot option, this also needs to be enabled from the BIOS before booting is allowed. Difference to the legacy mode is that the userspace software explicitly adds device UUIDs by sending a special message to the ICM firmware. Only the devices listed in the boot ACL are connected automatically during the boot. This works in both "user" and "secure" security levels. We implement this in Linux by exposing a new sysfs attribute (boot_acl) below each Thunderbolt domain. The userspace software can then update the full list as needed. Signed-off-by: Mika Westerberg Reviewed-by: Andy Shevchenko

thunderbolt: Add 'boot' attribute for devices

2018-03-09T09:54:11Z

In various cases, Thunderbolt device can be connected by ICM on boot without waiting for approval from user. Most cases are related to OEM-specific BIOS configurations. This information is interesting for user-space as if the device isn't in SW ACL, it may create a friction in the user experience where the device is automatically authorized if it's connected on boot but requires an explicit user action if connected after OS is up. User-space can use this information to suggest adding the device to SW ACL for auto-authorization on later connections. Signed-off-by: Yehezkel Bernat Signed-off-by: Mika Westerberg Reviewed-by: Andy Shevchenko

thunderbolt: Add tb_switch_find_by_route()

2018-03-09T09:54:10Z

With the new ICM messaging there is need for find switch by route string instead of link and depth. Add new function that makes it possible. Signed-off-by: Radion Mirchevsky Signed-off-by: Mika Westerberg Reviewed-by: Andy Shevchenko

thunderbolt: Add tb_switch_get()

2018-03-09T09:54:10Z

Sometimes there is need for increasing reference count of a switch as well. This also follows what we have for xdomains. Signed-off-by: Mika Westerberg Reviewed-by: Andy Shevchenko

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-11-04T00:26:51Z

Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman