From patchwork Fri Nov 11 13:58:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 13040444 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 4C83AC4167B for ; Fri, 11 Nov 2022 14:08:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234418AbiKKOIC (ORCPT ); Fri, 11 Nov 2022 09:08:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234538AbiKKOHE (ORCPT ); Fri, 11 Nov 2022 09:07:04 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BABF8BA9A; Fri, 11 Nov 2022 05:59:54 -0800 (PST) Message-ID: <20221111135206.577311313@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1668175128; 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=mJmHAB47qeb6IUi2Y32Du0kAFRIPWB4ryIU41lcPdlU=; b=Es3G7f5rs9OUwN0q+XJwuuFDMW8Sa2dIkA12T5rGe149QBr/Clg5tg3h8KS6Y3lqOa7DKX kRVv6kb2e1gjqdIFdViIls/t/v7qWcRjlwusBOAPvVXM5t4H8Esa7Q+iMTqIR5+AJzwiXs IW6Gooq0mT56hnTJuFQXGQXcIj1u4OEyGOLCgAn01oR1ZupSRLuzXFYR5tcxQDzui+mBD/ 2xQ7yV6JTIadLwBURynsakqriTw8lPNKvEliTG5+gUmnTqjxx7ikY5tPYJ2h2eBxDP1tKN Vx04jvfc/6f67c//TP5yJY2hJRNY/TI7zHpp3Jwm9igMThHROOXGFSOhSr3Tqg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1668175128; 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=mJmHAB47qeb6IUi2Y32Du0kAFRIPWB4ryIU41lcPdlU=; b=6ykBQdi9Jjv/HQF5V93KoQiWqbkwO8yTGjUI40h6Kqi9dJ6z7H6qF/h2kI9Cag9s/igkqe zkr2QnymqOLTMXDQ== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Joerg Roedel , Will Deacon , linux-pci@vger.kernel.org, Bjorn Helgaas , Lorenzo Pieralisi , Marc Zyngier , Greg Kroah-Hartman , Jason Gunthorpe , Dave Jiang , Alex Williamson , Kevin Tian , Dan Williams , Logan Gunthorpe , Ashok Raj , Jon Mason , Allen Hubbe , "Ahmed S. Darwish" , Reinette Chatre Subject: [patch 23/33] PCI/MSI: Split MSIX descriptor setup References: <20221111133158.196269823@linutronix.de> MIME-Version: 1.0 Date: Fri, 11 Nov 2022 14:58:47 +0100 (CET) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The upcoming mechanism to allocate MSI-X vectors after enabling MSI-X needs to share some of the MSI-X descriptor setup. The regular descriptor setup on enable has the following code flow: 1) Allocate descriptor 2) Setup descriptor with PCI specific data 3) Insert descriptor 4) Allocate interrupts which in turn scans the inserted descriptors This cannot be easily changed because the PCI/MSI code needs to handle the legacy architecture specific allocation model and the irq domain model where quite some domains have the assumption that the above flow is how it works. Ideally the code flow should look like this: 1) Invoke allocation at the MSI core 2) MSI core allocates descriptor 3) MSI core calls back into the irq domain which fills in the domain specific parts This could be done for underlying parent MSI domains which support post-enable allocation/free but that would create significantly different code pathes for MSI/MSI-X enable. Though for dynamic allocation which wants to share the allocation code with the upcoming PCI/IMS support its the right thing to do. Split the MSIX descriptor setup into the preallocation part which just sets the index and fills in the horrible hack of virtual IRQs and the real PCI specific MSI-X setup part which solely depends on the index in the descriptor. This allows to provide a common dynami allocation interface at the MSI core level for both PCI/MSI-X and PCI/IMS. Signed-off-by: Thomas Gleixner Acked-by: Bjorn Helgaas --- drivers/pci/msi/msi.c | 72 +++++++++++++++++++++++++++++++------------------- drivers/pci/msi/msi.h | 2 + 2 files changed, 47 insertions(+), 27 deletions(-) --- a/drivers/pci/msi/msi.c +++ b/drivers/pci/msi/msi.c @@ -569,34 +569,56 @@ static void __iomem *msix_map_region(str return ioremap(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE); } -static int msix_setup_msi_descs(struct pci_dev *dev, void __iomem *base, - struct msix_entry *entries, int nvec, - struct irq_affinity_desc *masks) +/** + * msix_prepare_msi_desc - Prepare a half initialized MSI descriptor for operation + * @dev: The PCI device for which the descriptor is prepared + * @desc: The MSI descriptor for preparation + * + * This is seperate from msix_setup_msi_descs() below to handle dynamic + * allocations for MSIX after initial enablement. + * + * Ideally the whole MSIX setup would work that way, but there is no way to + * support this for the legacy arch_setup_msi_irqs() mechanism and for the + * fake irq domains like the x86 XEN one. Sigh... + * + * The descriptor is zeroed and only @desc::msi_index and @desc::affinity + * are set. When called from msix_setup_msi_descs() then the is_virtual + * attribute is initialized as well. + * + * Fill in the rest. + */ +void msix_prepare_msi_desc(struct pci_dev *dev, struct msi_desc *desc) +{ + desc->nvec_used = 1; + desc->pci.msi_attrib.is_msix = 1; + desc->pci.msi_attrib.is_64 = 1; + desc->pci.msi_attrib.default_irq = dev->irq; + desc->pci.mask_base = dev->msix_base; + desc->pci.msi_attrib.can_mask = !pci_msi_ignore_mask && + !desc->pci.msi_attrib.is_virtual; + + if (desc->pci.msi_attrib.can_mask) { + void __iomem *addr = pci_msix_desc_addr(desc); + + desc->pci.msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL); + } +} + +static int msix_setup_msi_descs(struct pci_dev *dev, struct msix_entry *entries, + int nvec, struct irq_affinity_desc *masks) { int ret = 0, i, vec_count = pci_msix_vec_count(dev); struct irq_affinity_desc *curmsk; struct msi_desc desc; - void __iomem *addr; memset(&desc, 0, sizeof(desc)); - desc.nvec_used = 1; - desc.pci.msi_attrib.is_msix = 1; - desc.pci.msi_attrib.is_64 = 1; - desc.pci.msi_attrib.default_irq = dev->irq; - desc.pci.mask_base = base; - for (i = 0, curmsk = masks; i < nvec; i++, curmsk++) { desc.msi_index = entries ? entries[i].entry : i; desc.affinity = masks ? curmsk : NULL; desc.pci.msi_attrib.is_virtual = desc.msi_index >= vec_count; - desc.pci.msi_attrib.can_mask = !pci_msi_ignore_mask && - !desc.pci.msi_attrib.is_virtual; - if (desc.pci.msi_attrib.can_mask) { - addr = pci_msix_desc_addr(&desc); - desc.pci.msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL); - } + msix_prepare_msi_desc(dev, &desc); ret = msi_insert_msi_desc(&dev->dev, &desc); if (ret) @@ -629,9 +651,8 @@ static void msix_mask_all(void __iomem * writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL); } -static int msix_setup_interrupts(struct pci_dev *dev, void __iomem *base, - struct msix_entry *entries, int nvec, - struct irq_affinity *affd) +static int msix_setup_interrupts(struct pci_dev *dev, struct msix_entry *entries, + int nvec, struct irq_affinity *affd) { struct irq_affinity_desc *masks = NULL; int ret; @@ -640,7 +661,7 @@ static int msix_setup_interrupts(struct masks = irq_create_affinity_masks(nvec, affd); msi_lock_descs(&dev->dev); - ret = msix_setup_msi_descs(dev, base, entries, nvec, masks); + ret = msix_setup_msi_descs(dev, entries, nvec, masks); if (ret) goto out_free; @@ -678,7 +699,6 @@ static int msix_setup_interrupts(struct static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries, int nvec, struct irq_affinity *affd) { - void __iomem *base; int ret, tsize; u16 control; @@ -696,15 +716,13 @@ static int msix_capability_init(struct p pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control); /* Request & Map MSI-X table region */ tsize = msix_table_size(control); - base = msix_map_region(dev, tsize); - if (!base) { + dev->msix_base = msix_map_region(dev, tsize); + if (!dev->msix_base) { ret = -ENOMEM; goto out_disable; } - dev->msix_base = base; - - ret = msix_setup_interrupts(dev, base, entries, nvec, affd); + ret = msix_setup_interrupts(dev, entries, nvec, affd); if (ret) goto out_disable; @@ -719,7 +737,7 @@ static int msix_capability_init(struct p * which takes the MSI-X mask bits into account even * when MSI-X is disabled, which prevents MSI delivery. */ - msix_mask_all(base, tsize); + msix_mask_all(dev->msix_base, tsize); pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0); pcibios_free_irq(dev); --- a/drivers/pci/msi/msi.h +++ b/drivers/pci/msi/msi.h @@ -84,6 +84,8 @@ static inline __attribute_const__ u32 ms return (1 << (1 << desc->pci.msi_attrib.multi_cap)) - 1; } +void msix_prepare_msi_desc(struct pci_dev *dev, struct msi_desc *desc); + /* Subsystem variables */ extern int pci_msi_enable;