From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from galois.linutronix.de (Galois.linutronix.de. [2a0a:51c0:0:12e:550::1]) by gmr-mx.google.com with ESMTPS id z64si92196wmc.0.2021.12.06.14.51.11 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Dec 2021 14:51:11 -0800 (PST) Message-ID: <20211206210747.873833567@linutronix.de> From: Thomas Gleixner Subject: [patch V2 05/31] genirq/msi: Provide msi_alloc_msi_desc() and a simple allocator References: <20211206210600.123171746@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Mon, 6 Dec 2021 23:51:10 +0100 (CET) To: LKML Cc: Bjorn Helgaas , Marc Zygnier , Alex Williamson , Kevin Tian , Jason Gunthorpe , Megha Dey , Ashok Raj , linux-pci@vger.kernel.org, Cedric Le Goater , xen-devel@lists.xenproject.org, Juergen Gross , Greg Kroah-Hartman , Niklas Schnelle , linux-s390@vger.kernel.org, Heiko Carstens , Christian Borntraeger , Logan Gunthorpe , Jon Mason , Dave Jiang , Allen Hubbe , linux-ntb@googlegroups.com List-ID: Provide msi_alloc_msi_desc() which takes a template MSI descriptor for initializing a newly allocated descriptor. This allows to simplify various usage sites of alloc_msi_entry() and moves the storage handling into the core code. For simple cases where only a linear vector space is required provide msi_add_simple_msi_descs() which just allocates a linear range of MSI descriptors and fills msi_desc::msi_index accordingly. Signed-off-by: Thomas Gleixner --- include/linux/msi.h | 2 + kernel/irq/msi.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 61 insertions(+) --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -264,6 +264,8 @@ static inline void pci_write_msi_msg(uns } #endif /* CONFIG_PCI_MSI */ +int msi_add_msi_desc(struct device *dev, struct msi_desc *init_desc); + struct msi_desc *alloc_msi_entry(struct device *dev, int nvec, const struct irq_affinity_desc *affinity); void free_msi_entry(struct msi_desc *entry); --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -61,6 +61,65 @@ void free_msi_entry(struct msi_desc *ent } /** + * msi_add_msi_desc - Allocate and initialize a MSI descriptor + * @dev: Pointer to the device for which the descriptor is allocated + * @init_desc: Pointer to an MSI descriptor to initialize the new descriptor + * + * Return: 0 on success or an appropriate failure code. + */ +int msi_add_msi_desc(struct device *dev, struct msi_desc *init_desc) +{ + struct msi_desc *desc; + + lockdep_assert_held(&dev->msi.data->mutex); + + desc = alloc_msi_entry(dev, init_desc->nvec_used, init_desc->affinity); + if (!desc) + return -ENOMEM; + + /* Copy the MSI index and type specific data to the new descriptor. */ + desc->msi_index = init_desc->msi_index; + desc->pci = init_desc->pci; + + list_add_tail(&desc->list, &dev->msi.data->list); + return 0; +} + +/** + * msi_add_simple_msi_descs - Allocate and initialize MSI descriptors + * @dev: Pointer to the device for which the descriptors are allocated + * @index: Index for the first MSI descriptor + * @ndesc: Number of descriptors to allocate + * + * Return: 0 on success or an appropriate failure code. + */ +static int msi_add_simple_msi_descs(struct device *dev, unsigned int index, unsigned int ndesc) +{ + struct msi_desc *desc, *tmp; + LIST_HEAD(list); + unsigned int i; + + lockdep_assert_held(&dev->msi.data->mutex); + + for (i = 0; i < ndesc; i++) { + desc = alloc_msi_entry(dev, 1, NULL); + if (!desc) + goto fail; + desc->msi_index = index + i; + list_add_tail(&desc->list, &list); + } + list_splice_tail(&list, &dev->msi.data->list); + return 0; + +fail: + list_for_each_entry_safe(desc, tmp, &list, list) { + list_del(&desc->list); + free_msi_entry(desc); + } + return -ENOMEM; +} + +/** * msi_device_set_properties - Set device specific MSI properties * @dev: Pointer to the device which is queried * @prop: Properties to set