[tip: irq/core] genirq: Merge irqaction::{dev_id,percpu_dev_id}

tip-bot2 for Marc Zyngier
2025-10-27T16:31:11Z

The following commit has been merged into the irq/core branch of tip:

Commit-ID: 5c2b2cc472e015e79c4f0170893a1e0883bd3bb4
Gitweb: https://git.kernel.org/tip/5c2b2cc472e015e79c4f0170893a1e0883bd3bb4
Author: Marc Zyngier <maz@kernel.org>
AuthorDate: Mon, 20 Oct 2025 13:29:29 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 27 Oct 2025 17:16:34 +01:00

genirq: Merge irqaction::{dev_id,percpu_dev_id}

When irqaction::percpu_dev_id was introduced, it was hoped that it could be
part of an anonymous union with dev_id, as the two fields are mutually
exclusive.

However, toolchains used at the time were often showing terrible support
for anonymous unions, breaking the build on a number of architectures. It
was therefore decided to keep the two fields separate and address this down
the line.

14 years later, the compiler dark age is over, and there is universal
support for anonymous unions. Get a whole pointer back that can immediately
be spent on something else.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20251020122944.3074811-13-maz@kernel.org
---
include/linux/interrupt.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 51b6484..0ec1a71 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -121,8 +121,10 @@ typedef irqreturn_t (*irq_handler_t)(int, void *);
*/
struct irqaction {
irq_handler_t handler;
- void *dev_id;
- void __percpu *percpu_dev_id;
+ union {
+ void *dev_id;
+ void __percpu *percpu_dev_id;
+ };
struct irqaction *next;
irq_handler_t thread_fn;
struct task_struct *thread;