From: "H. Peter Anvin" <hpa@zytor.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Andy Lutomirski <luto@kernel.org>,
Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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 [thread overview]
Message-ID: <20210515095907.3020486-1-hpa@zytor.com> (raw)
In-Reply-To: <20210515014400.2999028-8-hpa@zytor.com>
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
next prev parent reply other threads:[~2021-05-15 9:59 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-15 1:43 [PATCH v2 0/8] x86/irq: trap and interrupt cleanups H. Peter Anvin
2021-05-15 1:43 ` [PATCH v2 1/9] x86/traps: add X86_NR_HW_TRAPS to <asm/trapnr.h> H. Peter Anvin
2021-05-15 1:43 ` [PATCH v2 2/9] x86/irqvector: add NR_EXTERNAL_VECTORS and NR_SYSTEM_VECTORS H. Peter Anvin
2021-05-15 1:43 ` [PATCH v2 3/9] x86/irq: remove unused vectors from <asm/irq_vectors.h> H. Peter Anvin
2021-05-15 1:43 ` [PATCH v2 4/9] x86/idt: remove address argument to idt_invalidate() H. Peter Anvin
2021-05-15 15:27 ` Andy Lutomirski
2021-05-15 1:43 ` [PATCH v2 5/9] x86/desc: add native_[ig]dt_invalidate() to <asm/desc.h> H. Peter Anvin
2021-05-15 15:29 ` Andy Lutomirski
2021-05-15 1:43 ` [PATCH v2 6/9] x86/kexec: set_[gi]dt() -> native_[gi]dt_invalidate() in machine_kexec_*.c H. Peter Anvin
2021-05-15 15:30 ` Andy Lutomirski
2021-05-15 1:43 ` [PATCH v2 7/9] x86/irq: WARN_ONCE() if irq_move_cleanup is called on a pending interrupt H. Peter Anvin
2021-05-15 6:24 ` H. Peter Anvin
2021-05-15 9:59 ` H. Peter Anvin [this message]
2021-05-15 1:44 ` [PATCH v2 8/9] x86/irq: merge and functionalize common code in DECLARE/DEFINE_IDTENTRY_* H. Peter Anvin
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