109 lines
3.6 KiB
Diff
109 lines
3.6 KiB
Diff
From: Thomas Gleixner <tglx@linutronix.de>
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Date: Tue, 17 Jul 2018 18:25:31 +0200
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Subject: [PATCH 013/290] x86/ioapic: Don't let setaffinity unmask threaded EOI
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interrupt too early
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Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=269b937b10ea6588bf79b4d789c40cc5214711cf
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There is an issue with threaded interrupts which are marked ONESHOT
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and using the fasteoi handler.
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if (IS_ONESHOT())
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mask_irq();
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....
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....
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cond_unmask_eoi_irq()
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chip->irq_eoi();
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So if setaffinity is pending then the interrupt will be moved and then
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unmasked, which is wrong as it should be kept masked up to the point where
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the threaded handler finished. It's not a real problem, the interrupt will
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just be able to fire before the threaded handler has finished, though the irq
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masked state will be wrong for a bit.
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The patch below should cure the issue. It also renames the horribly
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misnomed functions so it becomes clear what they are supposed to do.
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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[bigeasy: add the body of the patch, use the same functions in both
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ifdef paths (spotted by Andy Shevchenko)]
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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arch/x86/kernel/apic/io_apic.c | 23 +++++++++++++----------
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1 file changed, 13 insertions(+), 10 deletions(-)
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diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
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index ab22eded61d2..91db2ec0c10a 100644
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--- a/arch/x86/kernel/apic/io_apic.c
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+++ b/arch/x86/kernel/apic/io_apic.c
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@@ -1722,19 +1722,20 @@ static bool io_apic_level_ack_pending(struct mp_chip_data *data)
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return false;
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}
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-static inline bool ioapic_irqd_mask(struct irq_data *data)
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+static inline bool ioapic_prepare_move(struct irq_data *data)
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{
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/* If we are moving the irq we need to mask it */
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if (unlikely(irqd_is_setaffinity_pending(data))) {
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- mask_ioapic_irq(data);
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+ if (!irqd_irq_masked(data))
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+ mask_ioapic_irq(data);
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return true;
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}
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return false;
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}
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-static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked)
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+static inline void ioapic_finish_move(struct irq_data *data, bool moveit)
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{
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- if (unlikely(masked)) {
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+ if (unlikely(moveit)) {
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/* Only migrate the irq if the ack has been received.
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*
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* On rare occasions the broadcast level triggered ack gets
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@@ -1763,15 +1764,17 @@ static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked)
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*/
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if (!io_apic_level_ack_pending(data->chip_data))
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irq_move_masked_irq(data);
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- unmask_ioapic_irq(data);
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+ /* If the irq is masked in the core, leave it */
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+ if (!irqd_irq_masked(data))
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+ unmask_ioapic_irq(data);
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}
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}
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#else
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-static inline bool ioapic_irqd_mask(struct irq_data *data)
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+static inline bool ioapic_prepare_move(struct irq_data *data)
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{
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return false;
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}
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-static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked)
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+static inline void ioapic_finish_move(struct irq_data *data, bool moveit)
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{
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}
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#endif
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@@ -1780,11 +1783,11 @@ static void ioapic_ack_level(struct irq_data *irq_data)
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{
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struct irq_cfg *cfg = irqd_cfg(irq_data);
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unsigned long v;
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- bool masked;
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+ bool moveit;
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int i;
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irq_complete_move(cfg);
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- masked = ioapic_irqd_mask(irq_data);
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+ moveit = ioapic_prepare_move(irq_data);
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/*
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* It appears there is an erratum which affects at least version 0x11
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@@ -1839,7 +1842,7 @@ static void ioapic_ack_level(struct irq_data *irq_data)
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eoi_ioapic_pin(cfg->vector, irq_data->chip_data);
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}
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- ioapic_irqd_unmask(irq_data, masked);
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+ ioapic_finish_move(irq_data, moveit);
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}
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static void ioapic_ir_ack_level(struct irq_data *irq_data)
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