From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965319Ab2DKXpK (ORCPT ); Wed, 11 Apr 2012 19:45:10 -0400 Received: from gate.crashing.org ([63.228.1.57]:47684 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965172Ab2DKXpD (ORCPT ); Wed, 11 Apr 2012 19:45:03 -0400 Message-ID: <1334187888.2984.50.camel@pasglop> Subject: Re: [PATCH 1/3] irq_domain: remove "hint" when allocating irq numbers From: Benjamin Herrenschmidt To: Grant Likely Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Milton Miller , Olof Johansson Date: Thu, 12 Apr 2012 09:44:48 +1000 In-Reply-To: <1334186326-22649-2-git-send-email-grant.likely@secretlab.ca> References: <1334186326-22649-1-git-send-email-grant.likely@secretlab.ca> <1334186326-22649-2-git-send-email-grant.likely@secretlab.ca> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.2- Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2012-04-11 at 17:18 -0600, Grant Likely wrote: > The 'hint' used to try and line up irq numbers with hw irq numbers is > rather a hack and not very useful. It also had some value when irq > reverse mapping was lazy, and not done right at map time. However, the > lazy mapping is to be removed, so keeping around 'hint' isn't helpful > anymore. This patch removes it. Please document that this also removes the support for irq_virq_count, which breaks PS3, to be "fixed" by your patch 3/3 (you may want to re-order the patches here) and that fixes an actual bug with mapping of interrupts above NR_IRQS Cheers, Ben. > v2: Rebase onto v3.4-rc2 > > Signed-off-by: Grant Likely > Cc: Benjamin Herrenschmidt > Cc: Thomas Gleixner > Cc: Milton Miller > Cc: Olof Johansson > --- > kernel/irq/irqdomain.c | 23 ++++++----------------- > 1 files changed, 6 insertions(+), 17 deletions(-) > > diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c > index eb05e40..041710d 100644 > --- a/kernel/irq/irqdomain.c > +++ b/kernel/irq/irqdomain.c > @@ -4,6 +4,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -350,7 +351,6 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain) > unsigned int irq_create_mapping(struct irq_domain *domain, > irq_hw_number_t hwirq) > { > - unsigned int hint; > int virq; > > pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq); > @@ -378,14 +378,9 @@ unsigned int irq_create_mapping(struct irq_domain *domain, > return irq_domain_legacy_revmap(domain, hwirq); > > /* Allocate a virtual interrupt number */ > - hint = hwirq % irq_virq_count; > - if (hint == 0) > - hint++; > - virq = irq_alloc_desc_from(hint, 0); > - if (virq <= 0) > - virq = irq_alloc_desc_from(1, 0); > + virq = irq_alloc_desc_from(1, 0); > if (virq <= 0) { > - pr_debug("irq: -> virq allocation failed\n"); > + pr_debug("irq: irq_desc allocation failed\n"); > return 0; > } > > @@ -516,7 +511,7 @@ unsigned int irq_find_mapping(struct irq_domain *domain, > irq_hw_number_t hwirq) > { > unsigned int i; > - unsigned int hint = hwirq % irq_virq_count; > + struct irq_desc *desc; > > /* Look for default domain if nececssary */ > if (domain == NULL) > @@ -529,17 +524,11 @@ unsigned int irq_find_mapping(struct irq_domain *domain, > return irq_domain_legacy_revmap(domain, hwirq); > > /* Slow path does a linear search of the map */ > - if (hint == 0) > - hint = 1; > - i = hint; > - do { > + for_each_irq_desc(i, desc) { > struct irq_data *data = irq_get_irq_data(i); > if (data && (data->domain == domain) && (data->hwirq == hwirq)) > return i; > - i++; > - if (i >= irq_virq_count) > - i = 1; > - } while(i != hint); > + } > return 0; > } > EXPORT_SYMBOL_GPL(irq_find_mapping);