From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 26 Jan 2015 11:46:03 +0100 (CET) Received: from terminus.zytor.com ([198.137.202.10]:58362 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27010935AbbAZKqBjxQ1U (ORCPT ); Mon, 26 Jan 2015 11:46:01 +0100 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.14.8/8.14.7) with ESMTP id t0QAjXqZ000983; Mon, 26 Jan 2015 02:45:38 -0800 Received: (from tipbot@localhost) by terminus.zytor.com (8.14.8/8.14.7/Submit) id t0QAjXYm000980; Mon, 26 Jan 2015 02:45:33 -0800 Date: Mon, 26 Jan 2015 02:45:33 -0800 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Qais Yousef Message-ID: Cc: linux-mips@linux-mips.org, abrestic@chromium.org, jason@lakedaemon.net, mingo@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, qais.yousef@imgtec.com, hpa@zytor.com Reply-To: abrestic@chromium.org, linux-mips@linux-mips.org, jason@lakedaemon.net, linux-kernel@vger.kernel.org, qais.yousef@imgtec.com, tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com In-Reply-To: <1421668289-828-1-git-send-email-qais.yousef@imgtec.com> References: <1421668289-828-1-git-send-email-qais.yousef@imgtec.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:irq/core] irqchip: mips-gic: Handle pending interrupts once in __gic_irq_dispatch() Git-Commit-ID: d7eb4f2ecccd71f701bc8873bcf07c2d3b0375f6 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Precedence: bulk Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 45476 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: tipbot@zytor.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips Commit-ID: d7eb4f2ecccd71f701bc8873bcf07c2d3b0375f6 Gitweb: http://git.kernel.org/tip/d7eb4f2ecccd71f701bc8873bcf07c2d3b0375f6 Author: Qais Yousef AuthorDate: Mon, 19 Jan 2015 11:51:29 +0000 Committer: Thomas Gleixner CommitDate: Mon, 26 Jan 2015 11:38:23 +0100 irqchip: mips-gic: Handle pending interrupts once in __gic_irq_dispatch() When an interrupt occurs __gic_irq_dispatch() continuously reads local and shared pending registers until all is serviced before returning. The problem with that is that it could introduce a long delay before returning if a piece of hardware keeps triggering while in one of these loops. To ensure fairness and priority doesn't get skewed a lot, read local and shared pending registers once to service each pending IRQ once. If another interupt triggers while servicing the current ones, then we shall re-enter the handler after we return. Signed-off-by: Qais Yousef Cc: Jason Cooper Cc: Andrew Bresticker Cc: Link: http://lkml.kernel.org/r/1421668289-828-1-git-send-email-qais.yousef@imgtec.com Signed-off-by: Thomas Gleixner --- drivers/irqchip/irq-mips-gic.c | 44 +++++++++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 18 deletions(-) diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c index 2b0468e..f3f9873 100644 --- a/drivers/irqchip/irq-mips-gic.c +++ b/drivers/irqchip/irq-mips-gic.c @@ -234,9 +234,9 @@ int gic_get_c0_perfcount_int(void) GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_PERFCTR)); } -static unsigned int gic_get_int(void) +static void gic_handle_shared_int(void) { - unsigned int i; + unsigned int i, intr, virq; unsigned long *pcpu_mask; unsigned long pending_reg, intrmask_reg; DECLARE_BITMAP(pending, GIC_MAX_INTRS); @@ -258,7 +258,16 @@ static unsigned int gic_get_int(void) bitmap_and(pending, pending, intrmask, gic_shared_intrs); bitmap_and(pending, pending, pcpu_mask, gic_shared_intrs); - return find_first_bit(pending, gic_shared_intrs); + intr = find_first_bit(pending, gic_shared_intrs); + while (intr != gic_shared_intrs) { + virq = irq_linear_revmap(gic_irq_domain, + GIC_SHARED_TO_HWIRQ(intr)); + do_IRQ(virq); + + /* go to next pending bit */ + bitmap_clear(pending, intr, 1); + intr = find_first_bit(pending, gic_shared_intrs); + } } static void gic_mask_irq(struct irq_data *d) @@ -385,16 +394,26 @@ static struct irq_chip gic_edge_irq_controller = { #endif }; -static unsigned int gic_get_local_int(void) +static void gic_handle_local_int(void) { unsigned long pending, masked; + unsigned int intr, virq; pending = gic_read(GIC_REG(VPE_LOCAL, GIC_VPE_PEND)); masked = gic_read(GIC_REG(VPE_LOCAL, GIC_VPE_MASK)); bitmap_and(&pending, &pending, &masked, GIC_NUM_LOCAL_INTRS); - return find_first_bit(&pending, GIC_NUM_LOCAL_INTRS); + intr = find_first_bit(&pending, GIC_NUM_LOCAL_INTRS); + while (intr != GIC_NUM_LOCAL_INTRS) { + virq = irq_linear_revmap(gic_irq_domain, + GIC_LOCAL_TO_HWIRQ(intr)); + do_IRQ(virq); + + /* go to next pending bit */ + bitmap_clear(&pending, intr, 1); + intr = find_first_bit(&pending, GIC_NUM_LOCAL_INTRS); + } } static void gic_mask_local_irq(struct irq_data *d) @@ -453,19 +472,8 @@ static struct irq_chip gic_all_vpes_local_irq_controller = { static void __gic_irq_dispatch(void) { - unsigned int intr, virq; - - while ((intr = gic_get_local_int()) != GIC_NUM_LOCAL_INTRS) { - virq = irq_linear_revmap(gic_irq_domain, - GIC_LOCAL_TO_HWIRQ(intr)); - do_IRQ(virq); - } - - while ((intr = gic_get_int()) != gic_shared_intrs) { - virq = irq_linear_revmap(gic_irq_domain, - GIC_SHARED_TO_HWIRQ(intr)); - do_IRQ(virq); - } + gic_handle_local_int(); + gic_handle_shared_int(); } static void gic_irq_dispatch(unsigned int irq, struct irq_desc *desc)