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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 15D26C433F5 for ; Tue, 7 Dec 2021 21:03:53 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4J7t7q4Ybdz3cZF for ; Wed, 8 Dec 2021 08:03:51 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=XufeyuxA; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=145.40.73.55; helo=sin.source.kernel.org; envelope-from=helgaas@kernel.org; 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h=Date:From:To:Cc:Subject:In-Reply-To:From; b=XufeyuxA4HkM8C1emNf201uZTgp+dVqYnNX9ceYmkxirOcGK1GaoHMbJIhyz3E3+D cblky2T1a1/xUWCxvj7lXEc5xpM/dggclpp5CX7k6YatZZnXrjghPJwp9SiEWV/q8O VHUPzss9MvVyzoAJaMBsVgQVwIQWM4SF/FV26sZrL5XAcC2xU1v6GOa1BhFJPeHS5T wvm6bhOMRM9UNs8NKfy77ac0jMKUcnEUjJMGKEcxsgJrKNuqoW7tZRxDuYb0xt7/s7 4sSISKBZ3qSg8+5KsVWmnqztHkST9BbG9ZkniYgH9dpNrFmiv0QYea1HSrPMTJm/hB pRBsYEeNdamow== Date: Tue, 7 Dec 2021 15:02:19 -0600 From: Bjorn Helgaas To: Thomas Gleixner Subject: Re: [patch V2 22/23] genirq/msi: Handle PCI/MSI allocation fail in core code Message-ID: <20211207210219.GA77501@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211206210225.046615302@linutronix.de> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-hyperv@vger.kernel.org, linux-mips@vger.kernel.org, Paul Mackerras , sparclinux@vger.kernel.org, Wei Liu , Ashok Raj , x86@kernel.org, Christian Borntraeger , Megha Dey , Jason Gunthorpe , linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, ath11k@lists.infradead.org, Kevin Tian , Heiko Carstens , Alex Williamson , Cedric Le Goater , Kalle Valo , Juergen Gross , Thomas Bogendoerfer , Greg Kroah-Hartman , LKML , Marc Zygnier , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Dec 06, 2021 at 11:27:59PM +0100, Thomas Gleixner wrote: > Get rid of yet another irqdomain callback and let the core code return the > already available information of how many descriptors could be allocated. > > Signed-off-by: Thomas Gleixner > Tested-by: Juergen Gross > Reviewed-by: Jason Gunthorpe Acked-by: Bjorn Helgaas # PCI > --- > drivers/pci/msi/irqdomain.c | 13 ------------- > include/linux/msi.h | 5 +---- > kernel/irq/msi.c | 29 +++++++++++++++++++++++++---- > 3 files changed, 26 insertions(+), 21 deletions(-) > > --- a/drivers/pci/msi/irqdomain.c > +++ b/drivers/pci/msi/irqdomain.c > @@ -95,16 +95,6 @@ static int pci_msi_domain_check_cap(stru > return 0; > } > > -static int pci_msi_domain_handle_error(struct irq_domain *domain, > - struct msi_desc *desc, int error) > -{ > - /* Special handling to support __pci_enable_msi_range() */ > - if (pci_msi_desc_is_multi_msi(desc) && error == -ENOSPC) > - return 1; > - > - return error; > -} > - > static void pci_msi_domain_set_desc(msi_alloc_info_t *arg, > struct msi_desc *desc) > { > @@ -115,7 +105,6 @@ static void pci_msi_domain_set_desc(msi_ > static struct msi_domain_ops pci_msi_domain_ops_default = { > .set_desc = pci_msi_domain_set_desc, > .msi_check = pci_msi_domain_check_cap, > - .handle_error = pci_msi_domain_handle_error, > }; > > static void pci_msi_domain_update_dom_ops(struct msi_domain_info *info) > @@ -129,8 +118,6 @@ static void pci_msi_domain_update_dom_op > ops->set_desc = pci_msi_domain_set_desc; > if (ops->msi_check == NULL) > ops->msi_check = pci_msi_domain_check_cap; > - if (ops->handle_error == NULL) > - ops->handle_error = pci_msi_domain_handle_error; > } > } > > --- a/include/linux/msi.h > +++ b/include/linux/msi.h > @@ -286,7 +286,6 @@ struct msi_domain_info; > * @msi_check: Callback for verification of the domain/info/dev data > * @msi_prepare: Prepare the allocation of the interrupts in the domain > * @set_desc: Set the msi descriptor for an interrupt > - * @handle_error: Optional error handler if the allocation fails > * @domain_alloc_irqs: Optional function to override the default allocation > * function. > * @domain_free_irqs: Optional function to override the default free > @@ -295,7 +294,7 @@ struct msi_domain_info; > * @get_hwirq, @msi_init and @msi_free are callbacks used by the underlying > * irqdomain. > * > - * @msi_check, @msi_prepare, @handle_error and @set_desc are callbacks used by > + * @msi_check, @msi_prepare and @set_desc are callbacks used by > * msi_domain_alloc/free_irqs(). > * > * @domain_alloc_irqs, @domain_free_irqs can be used to override the > @@ -332,8 +331,6 @@ struct msi_domain_ops { > msi_alloc_info_t *arg); > void (*set_desc)(msi_alloc_info_t *arg, > struct msi_desc *desc); > - int (*handle_error)(struct irq_domain *domain, > - struct msi_desc *desc, int error); > int (*domain_alloc_irqs)(struct irq_domain *domain, > struct device *dev, int nvec); > void (*domain_free_irqs)(struct irq_domain *domain, > --- a/kernel/irq/msi.c > +++ b/kernel/irq/msi.c > @@ -538,6 +538,27 @@ static bool msi_check_reservation_mode(s > return desc->pci.msi_attrib.is_msix || desc->pci.msi_attrib.can_mask; > } > > +static int msi_handle_pci_fail(struct irq_domain *domain, struct msi_desc *desc, > + int allocated) > +{ > + switch(domain->bus_token) { > + case DOMAIN_BUS_PCI_MSI: > + case DOMAIN_BUS_VMD_MSI: > + if (IS_ENABLED(CONFIG_PCI_MSI)) > + break; > + fallthrough; > + default: > + return -ENOSPC; > + } > + > + /* Let a failed PCI multi MSI allocation retry */ > + if (desc->nvec_used > 1) > + return 1; > + > + /* If there was a successful allocation let the caller know */ > + return allocated ? allocated : -ENOSPC; > +} > + > int __msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, > int nvec) > { > @@ -546,6 +567,7 @@ int __msi_domain_alloc_irqs(struct irq_d > struct irq_data *irq_data; > struct msi_desc *desc; > msi_alloc_info_t arg = { }; > + int allocated = 0; > int i, ret, virq; > bool can_reserve; > > @@ -560,16 +582,15 @@ int __msi_domain_alloc_irqs(struct irq_d > dev_to_node(dev), &arg, false, > desc->affinity); > if (virq < 0) { > - ret = -ENOSPC; > - if (ops->handle_error) > - ret = ops->handle_error(domain, desc, ret); > - return ret; > + ret = msi_handle_pci_fail(domain, desc, allocated); > + goto cleanup; > } > > for (i = 0; i < desc->nvec_used; i++) { > irq_set_msi_desc_off(virq, i, desc); > irq_debugfs_copy_devname(virq + i, dev); > } > + allocated++; > } > > can_reserve = msi_check_reservation_mode(domain, info, dev); >