From: Shay Drory <shayd@nvidia.com>
Date: Tue, 6 Aug 2024 07:20:44 +0000 (+0300)
Subject: genirq/irqdesc: Honor caller provided affinity in alloc_desc()
X-Git-Tag: v6.11-rc3~3^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=edbbaae42a56f9a2b39c52ef2504dfb3fb0a7858;p=thirdparty%2Fkernel%2Flinux.git

genirq/irqdesc: Honor caller provided affinity in alloc_desc()

Currently, whenever a caller is providing an affinity hint for an
interrupt, the allocation code uses it to calculate the node and copies the
cpumask into irq_desc::affinity.

If the affinity for the interrupt is not marked 'managed' then the startup
of the interrupt ignores irq_desc::affinity and uses the system default
affinity mask.

Prevent this by setting the IRQD_AFFINITY_SET flag for the interrupt in the
allocator, which causes irq_setup_affinity() to use irq_desc::affinity on
interrupt startup if the mask contains an online CPU.

[ tglx: Massaged changelog ]

Fixes: 45ddcecbfa94 ("genirq: Use affinity hint in irqdesc allocation")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/all/20240806072044.837827-1-shayd@nvidia.com
---

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 07e99c936ba5d..1dee88ba0ae44 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -530,6 +530,7 @@ static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 				flags = IRQD_AFFINITY_MANAGED |
 					IRQD_MANAGED_SHUTDOWN;
 			}
+			flags |= IRQD_AFFINITY_SET;
 			mask = &affinity->mask;
 			node = cpu_to_node(cpumask_first(mask));
 			affinity++;