kernel/linux.git/include/linux/cpu_rmap.h, branch v6.6.131

lib: cpu_rmap: Add irq_cpu_rmap_remove to complement irq_cpu_rmap_add

2023-03-24T23:04:21+00:00

Add a function to complement irq_cpu_rmap_add(). It removes the irq from the reverse mapping by setting the notifier to NULL. The function calls irq_set_affinity_notifier() with NULL at the notify argument which then cancel any pending notifier work and decrement reference on the notifier. When ref count reaches zero, the glue pointer is kfree and the rmap entry is set to NULL serving both to avoid second attempt to release it and also making the rmap entry available for subsequent mapping. It should be noted the drivers usually creates the reverse mapping at initialization time and remove it at unload time so we do not expect failures in allocating rmap due to kref holding the glue entry. Cc: Thomas Gleixner Signed-off-by: Eli Cohen Signed-off-by: Saeed Mahameed Reviewed-by: Jacob Keller

lib: cpu_rmap: Use allocator for rmap entries

2023-03-24T23:04:10+00:00

Use a proper allocator for rmap entries using a naive for loop. The allocator relies on whether an entry is NULL to be considered free. Remove the used field of rmap which is not needed. Also, avoid crashing the kernel if an entry is not available. Cc: Thomas Gleixner Signed-off-by: Eli Cohen Signed-off-by: Saeed Mahameed Reviewed-by: Jacob Keller

lib: cpu_rmap: Replace zero-length array with flexible-array member

2020-04-18T20:44:55+00:00

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 inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] 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 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman

Remove GENERIC_HARDIRQ config option

2013-09-13T13:09:52+00:00

After the last architecture switched to generic hard irqs the config options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code for !CONFIG_GENERIC_HARDIRQS can be removed. Signed-off-by: Martin Schwidefsky

lib: cpu_rmap: avoid flushing all workqueues

2013-01-11T22:54:54+00:00

In some cases, free_irq_cpu_rmap() is called while holding a lock (eg rtnl). This can lead to deadlocks, because it invokes flush_scheduled_work() which ends up waiting for whole system workqueue to flush, but some pending works might try to acquire the lock we are already holding. This commit uses reference-counting to replace irq_run_affinity_notifiers(). It also removes irq_run_affinity_notifiers() altogether. [akpm@linux-foundation.org: eliminate free_cpu_rmap, rename cpu_rmap_reclaim() to cpu_rmap_release(), propagate kref_put() retval from cpu_rmap_put()] Signed-off-by: David Decotigny Reviewed-by: Ben Hutchings Acked-by: Eric Dumazet Reviewed-by: Josh Triplett Cc: "David S. Miller" Cc: Or Gerlitz Acked-by: Amir Vadai Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

net/rps: Protect cpu_rmap.h from double inclusion

2012-07-19T15:34:37+00:00

Signed-off-by: Amir Vadai Signed-off-by: Or Gerlitz Acked-by: Ben Hutchings Signed-off-by: David S. Miller

lib: cpu_rmap: CPU affinity reverse-mapping

2011-01-24T22:51:56+00:00

When initiating I/O on a multiqueue and multi-IRQ device, we may want to select a queue for which the response will be handled on the same or a nearby CPU. This requires a reverse-map of IRQ affinity. Add library functions to support a generic reverse-mapping from CPUs to objects with affinity and the specific case where the objects are IRQs. Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller