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path: root/drivers/misc/vcpu_stall_detector.c
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2024-12-01Get rid of 'remove_new' relic from platform driver structLinus Torvalds
The continual trickle of small conversion patches is grating on me, and is really not helping. Just get rid of the 'remove_new' member function, which is just an alias for the plain 'remove', and had a comment to that effect: /* * .remove_new() is a relic from a prototype conversion of .remove(). * New drivers are supposed to implement .remove(). Once all drivers are * converted to not use .remove_new any more, it will be dropped. */ This was just a tree-wide 'sed' script that replaced '.remove_new' with '.remove', with some care taken to turn a subsequent tab into two tabs to make things line up. I did do some minimal manual whitespace adjustment for places that used spaces to line things up. Then I just removed the old (sic) .remove_new member function, and this is the end result. No more unnecessary conversion noise. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-07-04misc: Register a PPI for the vcpu stall detection virtual deviceSebastian Ene
Request a PPI for each vCPU during probe which will be used by the host to communicate a stall detected event on the vCPU. When the host raises this interrupt from the virtual machine monitor, the guest is expected to handle the interrupt and panic. Signed-off-by: Sebastian Ene <sebastianene@google.com> Link: https://lore.kernel.org/r/20240703153732.3214238-3-sebastianene@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-05misc: vcpu_stall_detector: Convert to platform remove callback returning voidUwe Kleine-König
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/4b964bd133f5af11cabd51a4d8ed95025583eb93.1708508896.git.u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-04misc: Explicitly include correct DT includesRob Herring
The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Acked-by: Andrew Donnellan <ajd@linux.ibm.com> # cxl Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20230718143102.1065481-1-robh@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-14misc: Add a mechanism to detect stalls on guest vCPUsSebastian Ene
This driver creates per-cpu hrtimers which are required to do the periodic 'pet' operation. On a conventional watchdog-core driver, the userspace is responsible for delivering the 'pet' events by writing to the particular /dev/watchdogN node. In this case we require a strong thread affinity to be able to account for lost time on a per vCPU. This part of the driver is the 'frontend' which is reponsible for delivering the periodic 'pet' events, configuring the virtual peripheral and listening for cpu hotplug events. The other part of the driver is an emulated MMIO device which is part of the KVM virtual machine monitor and this part accounts for lost time by looking at the /proc/{}/task/{}/stat entries. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Will Deacon <will@kernel.org> Signed-off-by: Sebastian Ene <sebastianene@google.com> Link: https://lore.kernel.org/r/20220711081720.2870509-3-sebastianene@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>