Messages in this thread Patch in this message |  | | From | "H. Peter Anvin" <> | Subject | [PATCH v2.1 7/8] x86/irq: WARN_ONCE() if irq_move_cleanup is called on a pending interrupt | Date | Sat, 15 May 2021 02:59:07 -0700 |
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From: "H. Peter Anvin (Intel)" <hpa@zytor.com>
The current IRQ vector allocation code should be "clean" and never issue a IRQ_MOVE_CLEANUP_VECTOR IPI for an interrupt that could still be pending. This should make it possible to move it to the "normal" system IRQ vector range. This should probably be a three-step process:
1. Introduce this WARN_ONCE() on this event ever occurring. 2. Remove the self-IPI hack. 3. Move the IRQ_MOVE_CLEANUP_VECTOR to the sysvec range.
This implements step 1.
[ Previous versions of this patch had steps 2 and 3 reversed. ]
Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> --- arch/x86/kernel/apic/vector.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index 6dbdc7c22bb7..7ba2982a3585 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -939,9 +939,14 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_irq_move_cleanup) * to this CPU. IRQ_MOVE_CLEANUP_VECTOR is the lowest * priority external vector, so on return from this * interrupt the device interrupt will happen first. + * + * *** This should never happen with the current IRQ + * cleanup code, so WARN_ONCE() for now, and + * eventually get rid of this hack. */ irr = apic_read(APIC_IRR + (vector / 32 * 0x10)); if (irr & (1U << (vector % 32))) { + WARN_ONCE(1, "irq_move_cleanup called on still pending interrupt\n"); apic->send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR); continue; } -- 2.31.1
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