From: Valentin Schneider <valentin.schneider@arm.com> To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Marc Zyngier <maz@kernel.org>, Thomas Gleixner <tglx@linutronix.de>, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, Vincenzo Frascino <vincenzo.frascino@arm.com> Subject: [RFC PATCH v2 06/10] genirq: Don't mask IRQ within flow handler if IRQ is flow-masked Date: Tue, 25 May 2021 18:32:51 +0100 [thread overview] Message-ID: <20210525173255.620606-7-valentin.schneider@arm.com> (raw) In-Reply-To: <20210525173255.620606-1-valentin.schneider@arm.com> mask_irq() lets an IRQ with IRQD_IRQ_FLOW_MASKED set be further masked via chip->irq_mask(). This is necessary for unhandled IRQs as we want to keep them masked beyond eoi_irq() (which clears IRQD_IRQ_FLOW_MASKED). This is however not necessary in paths that do end up handling the IRQ and are bounded by a final eoi_irq() - this is the case for chips with IRQCHIP_AUTOMASKS_FLOW and IRQCHIP_EOI_THREADED. Make handle_strict_flow_irq() leverage IRQCHIP_AUTOMASKS_FLOW and issue an ack_irq() rather than a mask_ack_irq() when possible. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> --- kernel/irq/chip.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 699e70b51aae..c2ca6b748987 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -896,6 +896,12 @@ void handle_edge_eoi_irq(struct irq_desc *desc) } #endif +/* + * AUTOMASKS_FLOW tells us ack/eoi handle the masking, EOI_THREADED tells us + * that masking will persist until irq_finalize_oneshot() + */ +#define ONESHOT_AUTOMASK_FLAGS (IRQCHIP_AUTOMASKS_FLOW | IRQCHIP_EOI_THREADED) + /** * handle_strict_flow_irq - irq handler for strict controllers * @desc: the interrupt description structure for this irq @@ -909,10 +915,9 @@ void handle_strict_flow_irq(struct irq_desc *desc) struct irq_chip *chip = desc->irq_data.chip; raw_spin_lock(&desc->lock); - mask_ack_irq(desc); if (!irq_may_run(desc)) - goto out; + goto out_mask; desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING); @@ -922,10 +927,20 @@ void handle_strict_flow_irq(struct irq_desc *desc) */ if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) { desc->istate |= IRQS_PENDING; - goto out; + goto out_mask; } kstat_incr_irqs_this_cpu(desc); + /* + * Masking is required if IRQ is ONESHOT and we can't rely on the + * flow-masking persisting down to irq_finalize_oneshot() + * (in the IRQ thread). + */ + if ((desc->istate & IRQS_ONESHOT) && + ((chip->flags & ONESHOT_AUTOMASK_FLAGS) != ONESHOT_AUTOMASK_FLAGS)) + mask_ack_irq(desc); + else + ack_irq(desc); handle_irq_event(desc); @@ -933,7 +948,8 @@ void handle_strict_flow_irq(struct irq_desc *desc) raw_spin_unlock(&desc->lock); return; -out: +out_mask: + mask_ack_irq(desc); /* * XXX: this is where IRQCHIP_EOI_IF_HANDLED would be checked, but * it's conceptually incompatible with this handler (it breaks the -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Valentin Schneider <valentin.schneider@arm.com> To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Marc Zyngier <maz@kernel.org>, Thomas Gleixner <tglx@linutronix.de>, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, Vincenzo Frascino <vincenzo.frascino@arm.com> Subject: [RFC PATCH v2 06/10] genirq: Don't mask IRQ within flow handler if IRQ is flow-masked Date: Tue, 25 May 2021 18:32:51 +0100 [thread overview] Message-ID: <20210525173255.620606-7-valentin.schneider@arm.com> (raw) In-Reply-To: <20210525173255.620606-1-valentin.schneider@arm.com> mask_irq() lets an IRQ with IRQD_IRQ_FLOW_MASKED set be further masked via chip->irq_mask(). This is necessary for unhandled IRQs as we want to keep them masked beyond eoi_irq() (which clears IRQD_IRQ_FLOW_MASKED). This is however not necessary in paths that do end up handling the IRQ and are bounded by a final eoi_irq() - this is the case for chips with IRQCHIP_AUTOMASKS_FLOW and IRQCHIP_EOI_THREADED. Make handle_strict_flow_irq() leverage IRQCHIP_AUTOMASKS_FLOW and issue an ack_irq() rather than a mask_ack_irq() when possible. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> --- kernel/irq/chip.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 699e70b51aae..c2ca6b748987 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -896,6 +896,12 @@ void handle_edge_eoi_irq(struct irq_desc *desc) } #endif +/* + * AUTOMASKS_FLOW tells us ack/eoi handle the masking, EOI_THREADED tells us + * that masking will persist until irq_finalize_oneshot() + */ +#define ONESHOT_AUTOMASK_FLAGS (IRQCHIP_AUTOMASKS_FLOW | IRQCHIP_EOI_THREADED) + /** * handle_strict_flow_irq - irq handler for strict controllers * @desc: the interrupt description structure for this irq @@ -909,10 +915,9 @@ void handle_strict_flow_irq(struct irq_desc *desc) struct irq_chip *chip = desc->irq_data.chip; raw_spin_lock(&desc->lock); - mask_ack_irq(desc); if (!irq_may_run(desc)) - goto out; + goto out_mask; desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING); @@ -922,10 +927,20 @@ void handle_strict_flow_irq(struct irq_desc *desc) */ if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) { desc->istate |= IRQS_PENDING; - goto out; + goto out_mask; } kstat_incr_irqs_this_cpu(desc); + /* + * Masking is required if IRQ is ONESHOT and we can't rely on the + * flow-masking persisting down to irq_finalize_oneshot() + * (in the IRQ thread). + */ + if ((desc->istate & IRQS_ONESHOT) && + ((chip->flags & ONESHOT_AUTOMASK_FLAGS) != ONESHOT_AUTOMASK_FLAGS)) + mask_ack_irq(desc); + else + ack_irq(desc); handle_irq_event(desc); @@ -933,7 +948,8 @@ void handle_strict_flow_irq(struct irq_desc *desc) raw_spin_unlock(&desc->lock); return; -out: +out_mask: + mask_ack_irq(desc); /* * XXX: this is where IRQCHIP_EOI_IF_HANDLED would be checked, but * it's conceptually incompatible with this handler (it breaks the -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-05-25 17:33 UTC|newest] Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-25 17:32 [RFC PATCH v2 00/10] irqchip/irq-gic: Optimize masking by leveraging EOImode=1 Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider 2021-05-25 17:32 ` [RFC PATCH v2 01/10] genirq: Add chip flag to denote automatic IRQ (un)masking Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider 2021-05-25 17:32 ` [RFC PATCH v2 02/10] genirq: Define irq_ack() and irq_eoi() helpers Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider 2021-05-25 20:54 ` kernel test robot 2021-05-27 10:55 ` Marc Zyngier 2021-05-27 10:55 ` Marc Zyngier 2021-05-27 10:58 ` Marc Zyngier 2021-05-27 10:58 ` Marc Zyngier 2021-06-01 10:25 ` Valentin Schneider 2021-06-01 10:25 ` Valentin Schneider 2021-05-25 17:32 ` [RFC PATCH v2 03/10] genirq: Employ ack_irq() and eoi_irq() where relevant Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider 2021-05-25 17:32 ` [RFC PATCH v2 04/10] genirq: Add handle_strict_flow_irq() flow handler Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider 2021-05-25 17:32 ` [RFC PATCH v2 05/10] genirq: Let purely flow-masked ONESHOT irqs through unmask_threaded_irq() Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider [this message] 2021-05-25 17:32 ` [RFC PATCH v2 06/10] genirq: Don't mask IRQ within flow handler if IRQ is flow-masked Valentin Schneider 2021-05-25 17:32 ` [RFC PATCH v2 07/10] genirq, irq-gic-v3: Make NMI flow handlers use ->irq_ack() if available Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider 2021-05-25 17:32 ` [RFC PATCH v2 08/10] irqchip/gic-v3-its: Use irq_chip_ack_parent() Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider 2021-05-27 12:17 ` Marc Zyngier 2021-05-27 12:17 ` Marc Zyngier 2021-06-01 10:25 ` Valentin Schneider 2021-06-01 10:25 ` Valentin Schneider 2021-05-25 17:32 ` [RFC PATCH v2 09/10] irqchip/gic: Convert to handle_strict_flow_irq() Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider 2021-05-27 12:21 ` Marc Zyngier 2021-05-27 12:21 ` Marc Zyngier 2021-06-01 10:25 ` Valentin Schneider 2021-06-01 10:25 ` Valentin Schneider 2021-06-15 15:20 ` Valentin Schneider 2021-06-15 15:20 ` Valentin Schneider 2021-05-25 17:32 ` [RFC PATCH v2 10/10] irqchip/gic-v3: " Valentin Schneider 2021-05-25 17:32 ` Valentin Schneider 2021-05-25 17:34 ` [RFC PATCH v2 00/10] irqchip/irq-gic: Optimize masking by leveraging EOImode=1 Valentin Schneider 2021-05-25 17:34 ` Valentin Schneider 2021-05-27 11:17 ` Marc Zyngier 2021-05-27 11:17 ` Marc Zyngier 2021-06-01 10:25 ` Valentin Schneider 2021-06-01 10:25 ` Valentin Schneider 2021-06-03 15:32 ` Valentin Schneider 2021-06-03 15:32 ` Valentin Schneider 2021-06-08 15:29 ` Marc Zyngier 2021-06-08 15:29 ` Marc Zyngier 2021-06-08 17:58 ` Lorenzo Pieralisi 2021-06-08 17:58 ` Lorenzo Pieralisi
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