From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EFCAC433F5 for ; Sat, 27 Nov 2021 01:32:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352393AbhK0BgB (ORCPT ); Fri, 26 Nov 2021 20:36:01 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:40092 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350403AbhK0BcV (ORCPT ); Fri, 26 Nov 2021 20:32:21 -0500 Message-ID: <20211126232735.849307742@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1637976188; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=xspuuPHlg8ajQhUdujNFqpIxuocRS6Wrk8AGGuaaprc=; b=oUuhV6YNhYZSsu1xSqQ/Wyja4+NJPkNHsuav44foB2ugTFqopGzpnbU4yb3Gzps5UMkQuB zJNAWBtedRCkjC6laDiKJUQ7AaUmOQtb4txh40q3NZqYAyvXc0fP8t9Ccbmv5gwNJpGLHd 54j8d36EYt6fczm2qWEVWXZJjrC4lAkg7WfB3F5vU34UYprsEVUC87c3Jj4yR/6WRa+aK1 9ipfTM2cvFPzA20SeR6+1aaMPEAr2MbpxO0SgHu6xfZXJJj8cBKdgcC/JDx9vLQJWIHHZB vP1IT5Pe7I5siDK7Atsq4asW1IB/ME1tb/PybUurnpSkyz4LJWYDV/IufJSr3A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1637976188; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=xspuuPHlg8ajQhUdujNFqpIxuocRS6Wrk8AGGuaaprc=; b=A2TVGNfto9HCZW0DlFRRHzreuhjNi+k0EYZYgBhiMpZeTUgzrftb9Gh1xklQ/0yWo84QUg DL0SDAQTJNmWFaCg== From: Thomas Gleixner To: LKML Cc: Bjorn Helgaas , Marc Zygnier , Alex Williamson , Kevin Tian , Jason Gunthorpe , Megha Dey , Ashok Raj , linux-pci@vger.kernel.org, Greg Kroah-Hartman , linux-s390@vger.kernel.org, Heiko Carstens , Christian Borntraeger , Jon Mason , Dave Jiang , Allen Hubbe , linux-ntb@googlegroups.com Subject: [patch 26/32] platform-msi: Simplify platform device MSI code References: <20211126230957.239391799@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Sat, 27 Nov 2021 02:23:07 +0100 (CET) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The allocation code is overly complex. It tries to have the MSI index space packed, which is not working when an interrupt is freed. There is no requirement for this. The only requirement is that the MSI index is unique. Move the MSI descriptor allocation into msi_domain_populate_irqs() and use the Linux interrupt number as MSI index which fulfils the unique requirement. This requires to lock the MSI descriptors which makes the lock order reverse to the regular MSI alloc/free functions vs. the domain mutex. Assign a seperate lockdep class for these MSI device domains. Signed-off-by: Thomas Gleixner --- drivers/base/platform-msi.c | 88 +++++++++----------------------------------- kernel/irq/msi.c | 46 +++++++++++------------ 2 files changed, 40 insertions(+), 94 deletions(-) --- a/drivers/base/platform-msi.c +++ b/drivers/base/platform-msi.c @@ -246,6 +246,8 @@ void *platform_msi_get_host_data(struct return data->host_data; } +static struct lock_class_key platform_device_msi_lock_class; + /** * __platform_msi_create_device_domain - Create a platform-msi device domain * @@ -278,6 +280,13 @@ struct irq_domain * if (err) return NULL; + /* + * Use a separate lock class for the MSI descriptor mutex on + * platform MSI device domains because the descriptor mutex nests + * into the domain mutex. See alloc/free below. + */ + lockdep_set_class(&dev->msi.data->mutex, &platform_device_msi_lock_class); + data = dev->msi.data->platform_data; data->host_data = host_data; domain = irq_domain_create_hierarchy(dev->msi.domain, 0, @@ -300,75 +309,23 @@ struct irq_domain * return NULL; } -static void platform_msi_free_descs(struct device *dev, int base, int nvec) -{ - struct msi_desc *desc, *tmp; - - list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) { - if (desc->msi_index >= base && - desc->msi_index < (base + nvec)) { - list_del(&desc->list); - free_msi_entry(desc); - } - } -} - -static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq, - int nvec) -{ - struct msi_desc *desc; - int i, base = 0; - - if (!list_empty(dev_to_msi_list(dev))) { - desc = list_last_entry(dev_to_msi_list(dev), - struct msi_desc, list); - base = desc->msi_index + 1; - } - - for (i = 0; i < nvec; i++) { - desc = alloc_msi_entry(dev, 1, NULL); - if (!desc) - break; - - desc->msi_index = base + i; - desc->irq = virq + i; - - list_add_tail(&desc->list, dev_to_msi_list(dev)); - } - - if (i != nvec) { - /* Clean up the mess */ - platform_msi_free_descs(dev, base, nvec); - return -ENOMEM; - } - - return 0; -} - /** * platform_msi_device_domain_free - Free interrupts associated with a platform-msi * device domain * * @domain: The platform-msi device domain * @virq: The base irq from which to perform the free operation - * @nvec: How many interrupts to free from @virq + * @nr_irqs: How many interrupts to free from @virq */ void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int virq, - unsigned int nvec) + unsigned int nr_irqs) { struct platform_msi_priv_data *data = domain->host_data; - struct msi_desc *desc, *tmp; - for_each_msi_entry_safe(desc, tmp, data->dev) { - if (WARN_ON(!desc->irq || desc->nvec_used != 1)) - return; - if (!(desc->irq >= virq && desc->irq < (virq + nvec))) - continue; - - irq_domain_free_irqs_common(domain, desc->irq, 1); - list_del(&desc->list); - free_msi_entry(desc); - } + msi_lock_descs(data->dev); + irq_domain_free_irqs_common(domain, virq, nr_irqs); + msi_free_msi_descs_range(data->dev, MSI_DESC_ALL, virq, nr_irqs); + msi_unlock_descs(data->dev); } /** @@ -377,7 +334,7 @@ void platform_msi_device_domain_free(str * * @domain: The platform-msi device domain * @virq: The base irq from which to perform the allocate operation - * @nr_irqs: How many interrupts to free from @virq + * @nr_irqs: How many interrupts to allocate from @virq * * Return 0 on success, or an error code on failure. Must be called * with irq_domain_mutex held (which can only be done as part of a @@ -387,16 +344,7 @@ int platform_msi_device_domain_alloc(str unsigned int nr_irqs) { struct platform_msi_priv_data *data = domain->host_data; - int err; - - err = platform_msi_alloc_descs_with_irq(data->dev, virq, nr_irqs); - if (err) - return err; - - err = msi_domain_populate_irqs(domain->parent, data->dev, - virq, nr_irqs, &data->arg); - if (err) - platform_msi_device_domain_free(domain, virq, nr_irqs); + struct device *dev = data->dev; - return err; + return msi_domain_populate_irqs(domain->parent, dev, virq, nr_irqs, &data->arg); } --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -775,43 +775,41 @@ int msi_domain_prepare_irqs(struct irq_d } int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev, - int virq, int nvec, msi_alloc_info_t *arg) + int virq_base, int nvec, msi_alloc_info_t *arg) { struct msi_domain_info *info = domain->host_data; struct msi_domain_ops *ops = info->ops; struct msi_desc *desc; - int ret = 0; + int ret, virq; - for_each_msi_entry(desc, dev) { - /* Don't even try the multi-MSI brain damage. */ - if (WARN_ON(!desc->irq || desc->nvec_used != 1)) { - ret = -EINVAL; - break; + msi_lock_descs(dev); + for (virq = virq_base; virq < virq_base + nvec; virq++) { + desc = alloc_msi_entry(dev, 1, NULL); + if (!desc) { + ret = -ENOMEM; + goto fail; } - if (!(desc->irq >= virq && desc->irq < (virq + nvec))) - continue; + desc->msi_index = virq; + desc->irq = virq; + list_add_tail(&desc->list, &dev->msi.data->list); + dev->msi.data->num_descs++; ops->set_desc(arg, desc); - /* Assumes the domain mutex is held! */ - ret = irq_domain_alloc_irqs_hierarchy(domain, desc->irq, 1, - arg); + ret = irq_domain_alloc_irqs_hierarchy(domain, virq, 1, arg); if (ret) - break; + goto fail; - irq_set_msi_desc_off(desc->irq, 0, desc); - } - - if (ret) { - /* Mop up the damage */ - for_each_msi_entry(desc, dev) { - if (!(desc->irq >= virq && desc->irq < (virq + nvec))) - continue; - - irq_domain_free_irqs_common(domain, desc->irq, 1); - } + irq_set_msi_desc(virq, desc); } + msi_unlock_descs(dev); + return 0; +fail: + for (--virq; virq >= virq_base; virq--) + irq_domain_free_irqs_common(domain, virq, 1); + msi_free_msi_descs_range(dev, MSI_DESC_ALL, virq_base, nvec); + msi_unlock_descs(dev); return ret; } From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C609AC433F5 for ; Sat, 27 Nov 2021 02:15:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351433AbhK0CS3 (ORCPT ); Fri, 26 Nov 2021 21:18:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350174AbhK0CQO (ORCPT ); Fri, 26 Nov 2021 21:16:14 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0002BC08EB4C; Fri, 26 Nov 2021 17:31:24 -0800 (PST) Message-ID: <20211126232735.849307742@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1637976249; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=xspuuPHlg8ajQhUdujNFqpIxuocRS6Wrk8AGGuaaprc=; b=jtV6ouorVBb/GrbthCOgEhUZyBdycqhWRxLpHbnWIc9J/a0nDPIUtBiG44gqB4Lh6vbz65 xSy34oq2FNJ05jCfJIzKy9oSHDrttXEj08NSiX39dRoDU19wjRe4Wumukj96KlVVXFl3ou BKD76/9odmsTxqHrJaPPWGLxYVvINn/MzfYI6te7x6EEOXGTduwH7h/j485Gzgqt6vkV+e 48ehWb0bb3vPpCLXgeYR7c8fTHF606R+/huCx7xkiV3/43hCo16CysjGwSRnX0wIr/Lr8M jJNDOM+kBVvJhNaTl3bekIkcfDhcBYEf3ysSJvSiLlbETDRiTxe9etj+Ns3QQg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1637976249; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=xspuuPHlg8ajQhUdujNFqpIxuocRS6Wrk8AGGuaaprc=; b=B5LYXKw7uwS97i+rtjs5rjPXl2JMsgRBJiLmtKWZWgdfGQhjH9cXDzmSsSC6J76A/kHJhZ Be6SzShoYJmRZwAw== From: Thomas Gleixner To: LKML Cc: Bjorn Helgaas , Marc Zygnier , Alex Williamson , Kevin Tian , Jason Gunthorpe , Megha Dey , Ashok Raj , linux-pci@vger.kernel.org, Greg Kroah-Hartman , linux-s390@vger.kernel.org, Heiko Carstens , Christian Borntraeger , Jon Mason , Dave Jiang , Allen Hubbe , linux-ntb@googlegroups.com Subject: [patch 26/32] platform-msi: Simplify platform device MSI code References: <20211126230957.239391799@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Sat, 27 Nov 2021 02:24:09 +0100 (CET) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Message-ID: <20211127012409.2PbvYZdCmNDQ2_yYmKPEOax2whcBwd6qsT5p5AqcqVU@z> The allocation code is overly complex. It tries to have the MSI index space packed, which is not working when an interrupt is freed. There is no requirement for this. The only requirement is that the MSI index is unique. Move the MSI descriptor allocation into msi_domain_populate_irqs() and use the Linux interrupt number as MSI index which fulfils the unique requirement. This requires to lock the MSI descriptors which makes the lock order reverse to the regular MSI alloc/free functions vs. the domain mutex. Assign a seperate lockdep class for these MSI device domains. Signed-off-by: Thomas Gleixner --- drivers/base/platform-msi.c | 88 +++++++++----------------------------------- kernel/irq/msi.c | 46 +++++++++++------------ 2 files changed, 40 insertions(+), 94 deletions(-) --- a/drivers/base/platform-msi.c +++ b/drivers/base/platform-msi.c @@ -246,6 +246,8 @@ void *platform_msi_get_host_data(struct return data->host_data; } +static struct lock_class_key platform_device_msi_lock_class; + /** * __platform_msi_create_device_domain - Create a platform-msi device domain * @@ -278,6 +280,13 @@ struct irq_domain * if (err) return NULL; + /* + * Use a separate lock class for the MSI descriptor mutex on + * platform MSI device domains because the descriptor mutex nests + * into the domain mutex. See alloc/free below. + */ + lockdep_set_class(&dev->msi.data->mutex, &platform_device_msi_lock_class); + data = dev->msi.data->platform_data; data->host_data = host_data; domain = irq_domain_create_hierarchy(dev->msi.domain, 0, @@ -300,75 +309,23 @@ struct irq_domain * return NULL; } -static void platform_msi_free_descs(struct device *dev, int base, int nvec) -{ - struct msi_desc *desc, *tmp; - - list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) { - if (desc->msi_index >= base && - desc->msi_index < (base + nvec)) { - list_del(&desc->list); - free_msi_entry(desc); - } - } -} - -static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq, - int nvec) -{ - struct msi_desc *desc; - int i, base = 0; - - if (!list_empty(dev_to_msi_list(dev))) { - desc = list_last_entry(dev_to_msi_list(dev), - struct msi_desc, list); - base = desc->msi_index + 1; - } - - for (i = 0; i < nvec; i++) { - desc = alloc_msi_entry(dev, 1, NULL); - if (!desc) - break; - - desc->msi_index = base + i; - desc->irq = virq + i; - - list_add_tail(&desc->list, dev_to_msi_list(dev)); - } - - if (i != nvec) { - /* Clean up the mess */ - platform_msi_free_descs(dev, base, nvec); - return -ENOMEM; - } - - return 0; -} - /** * platform_msi_device_domain_free - Free interrupts associated with a platform-msi * device domain * * @domain: The platform-msi device domain * @virq: The base irq from which to perform the free operation - * @nvec: How many interrupts to free from @virq + * @nr_irqs: How many interrupts to free from @virq */ void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int virq, - unsigned int nvec) + unsigned int nr_irqs) { struct platform_msi_priv_data *data = domain->host_data; - struct msi_desc *desc, *tmp; - for_each_msi_entry_safe(desc, tmp, data->dev) { - if (WARN_ON(!desc->irq || desc->nvec_used != 1)) - return; - if (!(desc->irq >= virq && desc->irq < (virq + nvec))) - continue; - - irq_domain_free_irqs_common(domain, desc->irq, 1); - list_del(&desc->list); - free_msi_entry(desc); - } + msi_lock_descs(data->dev); + irq_domain_free_irqs_common(domain, virq, nr_irqs); + msi_free_msi_descs_range(data->dev, MSI_DESC_ALL, virq, nr_irqs); + msi_unlock_descs(data->dev); } /** @@ -377,7 +334,7 @@ void platform_msi_device_domain_free(str * * @domain: The platform-msi device domain * @virq: The base irq from which to perform the allocate operation - * @nr_irqs: How many interrupts to free from @virq + * @nr_irqs: How many interrupts to allocate from @virq * * Return 0 on success, or an error code on failure. Must be called * with irq_domain_mutex held (which can only be done as part of a @@ -387,16 +344,7 @@ int platform_msi_device_domain_alloc(str unsigned int nr_irqs) { struct platform_msi_priv_data *data = domain->host_data; - int err; - - err = platform_msi_alloc_descs_with_irq(data->dev, virq, nr_irqs); - if (err) - return err; - - err = msi_domain_populate_irqs(domain->parent, data->dev, - virq, nr_irqs, &data->arg); - if (err) - platform_msi_device_domain_free(domain, virq, nr_irqs); + struct device *dev = data->dev; - return err; + return msi_domain_populate_irqs(domain->parent, dev, virq, nr_irqs, &data->arg); } --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -775,43 +775,41 @@ int msi_domain_prepare_irqs(struct irq_d } int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev, - int virq, int nvec, msi_alloc_info_t *arg) + int virq_base, int nvec, msi_alloc_info_t *arg) { struct msi_domain_info *info = domain->host_data; struct msi_domain_ops *ops = info->ops; struct msi_desc *desc; - int ret = 0; + int ret, virq; - for_each_msi_entry(desc, dev) { - /* Don't even try the multi-MSI brain damage. */ - if (WARN_ON(!desc->irq || desc->nvec_used != 1)) { - ret = -EINVAL; - break; + msi_lock_descs(dev); + for (virq = virq_base; virq < virq_base + nvec; virq++) { + desc = alloc_msi_entry(dev, 1, NULL); + if (!desc) { + ret = -ENOMEM; + goto fail; } - if (!(desc->irq >= virq && desc->irq < (virq + nvec))) - continue; + desc->msi_index = virq; + desc->irq = virq; + list_add_tail(&desc->list, &dev->msi.data->list); + dev->msi.data->num_descs++; ops->set_desc(arg, desc); - /* Assumes the domain mutex is held! */ - ret = irq_domain_alloc_irqs_hierarchy(domain, desc->irq, 1, - arg); + ret = irq_domain_alloc_irqs_hierarchy(domain, virq, 1, arg); if (ret) - break; + goto fail; - irq_set_msi_desc_off(desc->irq, 0, desc); - } - - if (ret) { - /* Mop up the damage */ - for_each_msi_entry(desc, dev) { - if (!(desc->irq >= virq && desc->irq < (virq + nvec))) - continue; - - irq_domain_free_irqs_common(domain, desc->irq, 1); - } + irq_set_msi_desc(virq, desc); } + msi_unlock_descs(dev); + return 0; +fail: + for (--virq; virq >= virq_base; virq--) + irq_domain_free_irqs_common(domain, virq, 1); + msi_free_msi_descs_range(dev, MSI_DESC_ALL, virq_base, nvec); + msi_unlock_descs(dev); return ret; }