From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752596AbcHLKj2 (ORCPT ); Fri, 12 Aug 2016 06:39:28 -0400 Received: from smtpoutz300.laposte.net ([178.22.154.200]:57967 "EHLO smtp.laposte.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751529AbcHLKj0 (ORCPT ); Fri, 12 Aug 2016 06:39:26 -0400 Subject: Re: [PATCH 1/2] genirq: Generic chip: add irq_unmap_generic_chip To: Thomas Gleixner , Marc Zyngier , Jason Cooper References: <579F5C5A.2070507@laposte.net> Cc: LKML , Mason From: Sebastian Frias Message-ID: <57ADA75A.8040001@laposte.net> Date: Fri, 12 Aug 2016 12:39:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <579F5C5A.2070507@laposte.net> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-VR-SrcIP: 78.31.43.6 X-VR-FullState: 0 X-VR-Score: -100 X-VR-Cause-1: gggruggvucftvghtrhhoucdtuddrfeeluddruddtgdefudculddtuddrfeeltddrtddtmdcutefuodet X-VR-Cause-2: ggdotefrodftvfcurfhrohhfihhlvgemucfntefrqffuvffgnecuuegrihhlohhuthemucehtddtnecu X-VR-Cause-3: secvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefuvfhfhffkffgfgggjtgfgsehtjegr X-VR-Cause-4: tddtfeejnecuhfhrohhmpefuvggsrghsthhirghnucfhrhhirghsuceoshhfkeegsehlrghpohhsthgv X-VR-Cause-5: rdhnvghtqeenucfkphepjeekrdefuddrgeefrdeinecurfgrrhgrmhepmhhouggvpehsmhhtphhouhht X-VR-Cause-6: pdhhvghloheplgdujedvrddvjedrtddrvddugegnpdhinhgvthepjeekrdefuddrgeefrdeipdhmrghi X-VR-Cause-7: lhhfrhhomhepshhfkeegsehlrghpohhsthgvrdhnvghtpdhrtghpthhtohepthhglhigsehlihhnuhht X-VR-Cause-8: rhhonhhigidruggv X-VR-AvState: No X-VR-State: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I don't know if somebody has had the time to look at these patches, but if you have comments (even if related to removing the "fixes" tag if you don't consider this a fix) please let me know. Best regards, Sebastian On 08/01/2016 04:27 PM, Sebastian Frias wrote: > Without this patch irq_domain_disassociate() cannot properly release the > interrupt. > Indeed, irq_map_generic_chip() checks a bit on 'gc->installed' but said bit > is never cleared, only set. > > Commit 088f40b7b027 ("genirq: Generic chip: Add linear irq domain support") > added irq_map_generic_chip() function and also stated "This lacks a removal > function for now". > > This commit provides with an implementation of an unmap function that can > be called by irq_domain_disassociate(). > > Fixes: 088f40b7b027 ("genirq: Generic chip: Add linear irq domain support") > > Signed-off-by: Sebastian Frias > --- > > This is required by loadable modules requesting IRQs. > In our case rmmod will perform free_irq() + irq_dispose_mapping(). > Without the unmap call the module cannot request the IRQ after "rmmod" > because it is marked as "installed" by the first successful "insmod". > > NOTE: While the proposed unmap() function attempts to undo as much things > as done by the map() function, I did not find a way to undo the following: > > a) irq_gc_init_mask_cache(gc, dgc->gc_flags) > b) irq_set_lockdep_class(virq, &irq_nested_lock_class) > c) irq_modify_status(virq, dgc->irq_flags_to_clear, dgc->irq_flags_to_set) > > Feel free to comment on that matter. > > --- > kernel/irq/generic-chip.c | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) > > diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c > index abd286a..7b464cd 100644 > --- a/kernel/irq/generic-chip.c > +++ b/kernel/irq/generic-chip.c > @@ -411,8 +411,34 @@ int irq_map_generic_chip(struct irq_domain *d, unsigned int virq, > } > EXPORT_SYMBOL_GPL(irq_map_generic_chip); > > +void irq_unmap_generic_chip(struct irq_domain *d, unsigned int virq) > +{ > + struct irq_data *data = irq_domain_get_irq_data(d, virq); > + struct irq_domain_chip_generic *dgc = d->gc; > + struct irq_chip_generic *gc; > + unsigned int hw_irq = data->hwirq; > + int chip_idx, irq_idx; > + > + if (!d->gc) > + return; > + > + chip_idx = hw_irq / dgc->irqs_per_chip; > + if (chip_idx >= dgc->num_chips) > + return; > + gc = dgc->gc[chip_idx]; > + > + irq_idx = hw_irq % dgc->irqs_per_chip; > + > + clear_bit(irq_idx, &gc->installed); > + irq_domain_set_info(d, virq, hw_irq, > + &no_irq_chip, NULL, NULL, NULL, NULL); > + > +} > +EXPORT_SYMBOL_GPL(irq_unmap_generic_chip); > + > struct irq_domain_ops irq_generic_chip_ops = { > .map = irq_map_generic_chip, > + .unmap = irq_unmap_generic_chip, > .xlate = irq_domain_xlate_onetwocell, > }; > EXPORT_SYMBOL_GPL(irq_generic_chip_ops); >