diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2022-11-11 14:55:09 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2022-11-17 15:15:22 +0100 |
| commit | d2a463b297415ca6dd4d60bb1c867dd7c931587b (patch) | |
| tree | a6a2c0b1123cd0e5934f46a31c56301cef9134a2 /drivers/pci/msi | |
| parent | bab65e48cb064d67b488efb6888c06fd977a8245 (diff) | |
PCI/MSI: Reject multi-MSI early
When hierarchical MSI interrupt domains are enabled then there is no point
to do tons of work and detect the missing support for multi-MSI late in the
allocation path.
Just query the domain feature flags right away. The query function is going
to be used for other purposes later and has a mode argument which influences
the result:
ALLOW_LEGACY returns true when:
- there is no irq domain attached (legacy support)
- there is a irq domain attached which has the feature flag set
DENY_LEGACY returns only true when:
- there is a irq domain attached which has the feature flag set
This allows to use the function universally without ifdeffery in the
calling code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20221111122015.574339988@linutronix.de
Diffstat (limited to 'drivers/pci/msi')
| -rw-r--r-- | drivers/pci/msi/irqdomain.c | 22 | ||||
| -rw-r--r-- | drivers/pci/msi/msi.c | 4 | ||||
| -rw-r--r-- | drivers/pci/msi/msi.h | 9 |
3 files changed, 35 insertions, 0 deletions
diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c index edd0cc204e06..666ed21f2924 100644 --- a/drivers/pci/msi/irqdomain.c +++ b/drivers/pci/msi/irqdomain.c @@ -187,6 +187,28 @@ struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode, } EXPORT_SYMBOL_GPL(pci_msi_create_irq_domain); +/** + * pci_msi_domain_supports - Check for support of a particular feature flag + * @pdev: The PCI device to operate on + * @feature_mask: The feature mask to check for (full match) + * @mode: If ALLOW_LEGACY this grants the feature when there is no irq domain + * associated to the device. If DENY_LEGACY the lack of an irq domain + * makes the feature unsupported + */ +bool pci_msi_domain_supports(struct pci_dev *pdev, unsigned int feature_mask, + enum support_mode mode) +{ + struct msi_domain_info *info; + struct irq_domain *domain; + + domain = dev_get_msi_domain(&pdev->dev); + + if (!domain || !irq_domain_is_hierarchy(domain)) + return mode == ALLOW_LEGACY; + info = domain->host_data; + return (info->flags & feature_mask) == feature_mask; +} + /* * Users of the generic MSI infrastructure expect a device to have a single ID, * so with DMA aliases we have to pick the least-worst compromise. Devices with diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c index 794ec97c5b70..bc84647c6dbd 100644 --- a/drivers/pci/msi/msi.c +++ b/drivers/pci/msi/msi.c @@ -347,6 +347,10 @@ static int msi_capability_init(struct pci_dev *dev, int nvec, struct msi_desc *entry; int ret; + /* Reject multi-MSI early on irq domain enabled architectures */ + if (nvec > 1 && !pci_msi_domain_supports(dev, MSI_FLAG_MULTI_PCI_MSI, ALLOW_LEGACY)) + return 1; + /* * Disable MSI during setup in the hardware, but mark it enabled * so that setup code can evaluate it. diff --git a/drivers/pci/msi/msi.h b/drivers/pci/msi/msi.h index 8170ef2c5ad0..9d75b6fb3e0c 100644 --- a/drivers/pci/msi/msi.h +++ b/drivers/pci/msi/msi.h @@ -97,6 +97,15 @@ int __pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int void __pci_restore_msi_state(struct pci_dev *dev); void __pci_restore_msix_state(struct pci_dev *dev); +/* irq_domain related functionality */ + +enum support_mode { + ALLOW_LEGACY, + DENY_LEGACY, +}; + +bool pci_msi_domain_supports(struct pci_dev *dev, unsigned int feature_mask, enum support_mode mode); + /* Legacy (!IRQDOMAIN) fallbacks */ #ifdef CONFIG_PCI_MSI_ARCH_FALLBACKS |