From patchwork Tue Apr 6 09:35:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 12184675 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 08A4BC43460 for ; Tue, 6 Apr 2021 09:36:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9079613DF for ; Tue, 6 Apr 2021 09:36:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244881AbhDFJgc (ORCPT ); Tue, 6 Apr 2021 05:36:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:54984 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244860AbhDFJgc (ORCPT ); Tue, 6 Apr 2021 05:36:32 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 775D36124B; Tue, 6 Apr 2021 09:36:24 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lTi8E-005owA-Q8; Tue, 06 Apr 2021 10:36:22 +0100 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org Cc: Daniel Mack , Robert Jarzmik , Haojian Zhuang , Yoshinori Sato , Rich Felker , Thomas Bogendoerfer , Michael Ellerman , Thomas Gleixner Subject: [PATCH 1/9] irqdomain: Reimplement irq_linear_revmap() with irq_find_mapping() Date: Tue, 6 Apr 2021 10:35:49 +0100 Message-Id: <20210406093557.1073423-2-maz@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210406093557.1073423-1-maz@kernel.org> References: <20210406093557.1073423-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, daniel@zonque.org, robert.jarzmik@free.fr, haojian.zhuang@gmail.com, ysato@users.sourceforge.jp, dalias@libc.org, tsbogend@alpha.franken.de, mpe@ellerman.id.au, tglx@linutronix.de X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org irq_linear_revmap() is supposed to be a fast path for domain lookups, but it only exposes low-level details of the irqdomain implementation, details which are better kept private. The *overhead* between the two is only a function call and a couple of tests, so it is likely that noone can show any meaningful difference compared to the cost of taking an interrupt. Reimplement irq_linear_revmap() with irq_find_mapping() in order to preserve source code compatibility, and rename the internal field for a measure. Signed-off-by: Marc Zyngier --- include/linux/irqdomain.h | 22 +++++++++------------- kernel/irq/irqdomain.c | 6 +++--- 2 files changed, 12 insertions(+), 16 deletions(-) diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index 33cacc8af26d..b9600f24878a 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -154,9 +154,9 @@ struct irq_domain_chip_generic; * Revmap data, used internally by irq_domain * @revmap_direct_max_irq: The largest hwirq that can be set for controllers that * support direct mapping - * @revmap_size: Size of the linear map table @linear_revmap[] + * @revmap_size: Size of the linear map table @revmap[] * @revmap_tree: Radix map tree for hwirqs that don't fit in the linear map - * @linear_revmap: Linear table of hwirq->virq reverse mappings + * @revmap: Linear table of hwirq->virq reverse mappings */ struct irq_domain { struct list_head link; @@ -180,7 +180,7 @@ struct irq_domain { unsigned int revmap_size; struct radix_tree_root revmap_tree; struct mutex revmap_tree_mutex; - unsigned int linear_revmap[]; + unsigned int revmap[]; }; /* Irq domain flags */ @@ -396,24 +396,20 @@ static inline unsigned int irq_create_mapping(struct irq_domain *host, return irq_create_mapping_affinity(host, hwirq, NULL); } - /** - * irq_linear_revmap() - Find a linux irq from a hw irq number. + * irq_find_mapping() - Find a linux irq from a hw irq number. * @domain: domain owning this hardware interrupt * @hwirq: hardware irq number in that domain space - * - * This is a fast path alternative to irq_find_mapping() that can be - * called directly by irq controller code to save a handful of - * instructions. It is always safe to call, but won't find irqs mapped - * using the radix tree. */ +extern unsigned int irq_find_mapping(struct irq_domain *host, + irq_hw_number_t hwirq); + static inline unsigned int irq_linear_revmap(struct irq_domain *domain, irq_hw_number_t hwirq) { - return hwirq < domain->revmap_size ? domain->linear_revmap[hwirq] : 0; + return irq_find_mapping(domain, hwirq); } -extern unsigned int irq_find_mapping(struct irq_domain *host, - irq_hw_number_t hwirq); + extern unsigned int irq_create_direct_mapping(struct irq_domain *host); extern int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base, diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index d10ab1d689d5..dfa716305ea9 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -486,7 +486,7 @@ static void irq_domain_clear_mapping(struct irq_domain *domain, irq_hw_number_t hwirq) { if (hwirq < domain->revmap_size) { - domain->linear_revmap[hwirq] = 0; + domain->revmap[hwirq] = 0; } else { mutex_lock(&domain->revmap_tree_mutex); radix_tree_delete(&domain->revmap_tree, hwirq); @@ -499,7 +499,7 @@ static void irq_domain_set_mapping(struct irq_domain *domain, struct irq_data *irq_data) { if (hwirq < domain->revmap_size) { - domain->linear_revmap[hwirq] = irq_data->irq; + domain->revmap[hwirq] = irq_data->irq; } else { mutex_lock(&domain->revmap_tree_mutex); radix_tree_insert(&domain->revmap_tree, hwirq, irq_data); @@ -920,7 +920,7 @@ unsigned int irq_find_mapping(struct irq_domain *domain, /* Check if the hwirq is in the linear revmap. */ if (hwirq < domain->revmap_size) - return domain->linear_revmap[hwirq]; + return domain->revmap[hwirq]; rcu_read_lock(); data = radix_tree_lookup(&domain->revmap_tree, hwirq);