From: Ming Lei <ming.lei@redhat.com> To: linux-nvme@lists.infradead.org, Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com>, Jens Axboe <axboe@fb.com>, Keith Busch <keith.busch@intel.com>, linux-pci@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com> Subject: [PATCH V2 1/3] PCI/MSI: preference to returning -ENOSPC from pci_alloc_irq_vectors_affinity Date: Sat, 29 Dec 2018 11:26:48 +0800 [thread overview] Message-ID: <20181229032650.27256-2-ming.lei@redhat.com> (raw) In-Reply-To: <20181229032650.27256-1-ming.lei@redhat.com> The API of pci_alloc_irq_vectors_affinity() requires to return -ENOSPC if leass than @min_vecs interrupt vectors are available for @dev. However, this way may be changed by falling back to __pci_enable_msi_range(), for example, if the device isn't capable of MSI, __pci_enable_msi_range() will return -EINVAL, and finally it is returned to users of pci_alloc_irq_vectors_affinity() even though there are quite MSIX vectors available. This way violates the interface. Users of pci_alloc_irq_vectors_affinity() may try to reduce irq vectors and allocate vectors again in case that -ENOSPC is returned, such as NVMe, so we need to respect the current interface and give preference to -ENOSPC. Cc: Jens Axboe <axboe@fb.com>, Cc: Keith Busch <keith.busch@intel.com>, Cc: linux-pci@vger.kernel.org, Cc: Bjorn Helgaas <bhelgaas@google.com>, Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/pci/msi.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 7a1c8a09efa5..91b4f03fee91 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -1168,7 +1168,8 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, const struct irq_affinity *affd) { static const struct irq_affinity msi_default_affd; - int vecs = -ENOSPC; + int msix_vecs = -ENOSPC; + int msi_vecs = -ENOSPC; if (flags & PCI_IRQ_AFFINITY) { if (!affd) @@ -1179,16 +1180,17 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, } if (flags & PCI_IRQ_MSIX) { - vecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs, - affd); - if (vecs > 0) - return vecs; + msix_vecs = __pci_enable_msix_range(dev, NULL, min_vecs, + max_vecs, affd); + if (msix_vecs > 0) + return msix_vecs; } if (flags & PCI_IRQ_MSI) { - vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd); - if (vecs > 0) - return vecs; + msi_vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, + affd); + if (msi_vecs > 0) + return msi_vecs; } /* use legacy irq if allowed */ @@ -1199,7 +1201,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, } } - return vecs; + return msix_vecs == -ENOSPC ? msix_vecs : msi_vecs; } EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity); -- 2.9.5
WARNING: multiple messages have this Message-ID (diff)
From: ming.lei@redhat.com (Ming Lei) Subject: [PATCH V2 1/3] PCI/MSI: preference to returning -ENOSPC from pci_alloc_irq_vectors_affinity Date: Sat, 29 Dec 2018 11:26:48 +0800 [thread overview] Message-ID: <20181229032650.27256-2-ming.lei@redhat.com> (raw) In-Reply-To: <20181229032650.27256-1-ming.lei@redhat.com> The API of pci_alloc_irq_vectors_affinity() requires to return -ENOSPC if leass than @min_vecs interrupt vectors are available for @dev. However, this way may be changed by falling back to __pci_enable_msi_range(), for example, if the device isn't capable of MSI, __pci_enable_msi_range() will return -EINVAL, and finally it is returned to users of pci_alloc_irq_vectors_affinity() even though there are quite MSIX vectors available. This way violates the interface. Users of pci_alloc_irq_vectors_affinity() may try to reduce irq vectors and allocate vectors again in case that -ENOSPC is returned, such as NVMe, so we need to respect the current interface and give preference to -ENOSPC. Cc: Jens Axboe <axboe at fb.com>, Cc: Keith Busch <keith.busch at intel.com>, Cc: linux-pci at vger.kernel.org, Cc: Bjorn Helgaas <bhelgaas at google.com>, Signed-off-by: Ming Lei <ming.lei at redhat.com> --- drivers/pci/msi.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 7a1c8a09efa5..91b4f03fee91 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -1168,7 +1168,8 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, const struct irq_affinity *affd) { static const struct irq_affinity msi_default_affd; - int vecs = -ENOSPC; + int msix_vecs = -ENOSPC; + int msi_vecs = -ENOSPC; if (flags & PCI_IRQ_AFFINITY) { if (!affd) @@ -1179,16 +1180,17 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, } if (flags & PCI_IRQ_MSIX) { - vecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs, - affd); - if (vecs > 0) - return vecs; + msix_vecs = __pci_enable_msix_range(dev, NULL, min_vecs, + max_vecs, affd); + if (msix_vecs > 0) + return msix_vecs; } if (flags & PCI_IRQ_MSI) { - vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd); - if (vecs > 0) - return vecs; + msi_vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, + affd); + if (msi_vecs > 0) + return msi_vecs; } /* use legacy irq if allowed */ @@ -1199,7 +1201,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, } } - return vecs; + return msix_vecs == -ENOSPC ? msix_vecs : msi_vecs; } EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity); -- 2.9.5
next prev parent reply other threads:[~2018-12-29 4:45 UTC|newest] Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-12-29 3:26 [PATCH V2 0/3] nvme pci: two fixes on nvme_setup_irqs Ming Lei 2018-12-29 3:26 ` Ming Lei 2018-12-29 3:26 ` Ming Lei [this message] 2018-12-29 3:26 ` [PATCH V2 1/3] PCI/MSI: preference to returning -ENOSPC from pci_alloc_irq_vectors_affinity Ming Lei 2018-12-31 22:00 ` Bjorn Helgaas 2018-12-31 22:00 ` Bjorn Helgaas 2018-12-31 22:41 ` Keith Busch 2018-12-31 22:41 ` Keith Busch 2019-01-01 5:24 ` Ming Lei 2019-01-01 5:24 ` Ming Lei 2019-01-02 21:02 ` Bjorn Helgaas 2019-01-02 21:02 ` Bjorn Helgaas 2019-01-02 22:46 ` Keith Busch 2019-01-02 22:46 ` Keith Busch 2018-12-29 3:26 ` [PATCH V2 2/3] nvme pci: fix nvme_setup_irqs() Ming Lei 2018-12-29 3:26 ` [PATCH V2 3/3] nvme pci: introduce module parameter of 'default_queues' Ming Lei 2018-12-31 21:24 ` Bjorn Helgaas 2019-01-01 5:47 ` Ming Lei 2019-01-02 2:14 ` Shan Hai [not found] ` <20190102073607.GA25590@ming.t460p> [not found] ` <d59007c6-af13-318c-5c9d-438ad7d9149d@oracle.com> [not found] ` <20190102083901.GA26881@ming.t460p> 2019-01-03 2:04 ` Shan Hai 2019-01-02 20:11 ` Bjorn Helgaas 2019-01-03 2:12 ` Ming Lei 2019-01-03 2:52 ` Shan Hai 2019-01-03 3:11 ` Shan Hai 2019-01-03 3:31 ` Ming Lei 2019-01-03 4:36 ` Shan Hai 2019-01-03 10:34 ` Ming Lei 2019-01-04 2:53 ` Shan Hai 2019-01-03 4:51 ` Shan Hai 2019-01-03 3:21 ` Ming Lei 2019-01-14 13:13 ` [PATCH V2 0/3] nvme pci: two fixes on nvme_setup_irqs John Garry 2019-01-14 13:13 ` John Garry
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