kernel.git/arch/um/drivers/line.c, branch linux-5.13.y

um: Support dynamic IRQ allocation

2020-12-13T21:22:08Z

It's cumbersome and error-prone to keep adding fixed IRQ numbers, and for proper device wakeup support for the virtio/vhost-user support we need to have different IRQs for each device. Even if in theory two IRQs (with and without wake) might be sufficient, it's much easier to reason about it when we have dynamic number assignment. It also makes it easier to add new devices that may dynamically exist or depending on the configuration, etc. Add support for this, up to 64 IRQs (the same limit as epoll FDs we have right now). Since it's not easy to port all the existing places to dynamic allocation (some data is statically initialized) keep the low numbers are reserved for the existing hard-coded IRQ numbers. Acked-By: Anton Ivanov Signed-off-by: Johannes Berg Acked-By: Anton Ivanov Signed-off-by: Richard Weinberger

um: line: Don't free winch (with IRQ) under spinlock

2020-12-13T21:21:55Z

Lockdep correctly complains that one shouldn't call um_free_irq() with free_irq() inside under a spinlock since that will attempt to acquire a mutex. Rearrange the code to keep the list manipulations under the lock while moving the actual freeing outside of it, to avoid this. In particular, this removes the lockdep complaint at shutdown that I was seeing with lockdep enabled. Signed-off-by: Johannes Berg Acked-By: anton.ivanov@cambridgegreys.com Signed-off-by: Richard Weinberger

um: line, remove put_char

2020-06-24T14:53:37Z

um's put_char only calls write. And the tty layer/disciplines do the same if put_char is NULL. So we can safely remove this put_char wrapper. Signed-off-by: Jiri Slaby Cc: Jeff Dike Cc: Richard Weinberger Cc: Anton Ivanov Link: https://lore.kernel.org/r/20200615074856.18949-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

um: Add SPDX headers for files in arch/um/drivers

2019-09-15T19:37:16Z

Convert files to use SPDX header. All files are licensed under the GPLv2. Signed-off-by: Alex Dewar Signed-off-by: Richard Weinberger

um: Remove obsolete reenable_XX calls

2018-12-27T21:48:35Z

reenable_fd has been a NOP since the introduction of the EPOLL based interrupt controller. reenable_channel() is no longer needed as the flow control is now handled via the write IRQs on the channel. Signed-off-by: Anton Ivanov Signed-off-by: Richard Weinberger

um: Make line/tty semantics use true write IRQ

2018-10-29T21:34:16Z

This fixes a long standing bug where large amounts of output could freeze the tty (most commonly seen on stdio console). While the bug has always been there it became more pronounced after moving to the new interrupt controller. The line semantics are now changed to have true IRQ write semantics which should further improve the tty/line subsystem stability and performance Signed-off-by: Anton Ivanov Signed-off-by: Richard Weinberger

Epoll based IRQ controller

2018-02-19T18:38:51Z

1. Removes the need to walk the IRQ/Device list to determine who triggered the IRQ. 2. Improves scalability (up to several times performance improvement for cases with 10s of devices). 3. Improves UML baseline IO performance for one disk + one NIC use case by up to 10%. 4. Introduces write poll triggered IRQs. 5. Prerequisite for introducing high performance mmesg family of functions in network IO. 6. Fixes RNG shutdown which was leaking a file descriptor Signed-off-by: Anton Ivanov Signed-off-by: Richard Weinberger

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:29Z

We are going to split out of , which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder file that just maps to to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

uml: Fix unsafe pid reference to foreground process group

2014-11-06T00:26:13Z

Although the tty core maintains a pid reference for the foreground process group, if the foreground process group is changed that pid reference is dropped. Thus, the pid reference used for signalling could become stale. Safely obtain a pid reference to the foreground process group and release the reference after signalling is complete. cc: Jeff Dike Acked-by: Richard Weinberger Signed-off-by: Peter Hurley Reviewed-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

Merge 3.9-rc3 into tty-next

2013-03-21T23:07:34Z