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authorMarc Zyngier <maz@kernel.org>2021-11-04 21:01:29 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-11-21 15:44:14 +0300
commit06ce633b3bfd1077922c9ce76e0da0c3d1c527ed (patch)
tree3b28ee25d2c4cd409d7fce0b5253e87058086880
parenta912418410ab64eec86d31cc166b4df48b7bd9e9 (diff)
downloadlinux-06ce633b3bfd1077922c9ce76e0da0c3d1c527ed.tar.xz
PCI/MSI: Deal with devices lying about their MSI mask capability
commit 2226667a145db2e1f314d7f57fd644fe69863ab9 upstream. It appears that some devices are lying about their mask capability, pretending that they don't have it, while they actually do. The net result is that now that we don't enable MSIs on such endpoint. Add a new per-device flag to deal with this. Further patches will make use of it, sadly. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20211104180130.3825416-2-maz@kernel.org Cc: Bjorn Helgaas <helgaas@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/pci/msi.c3
-rw-r--r--include/linux/pci.h2
2 files changed, 5 insertions, 0 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index ea6371eb9b25..e2dedfa9072d 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -477,6 +477,9 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
goto out;
pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
+ /* Lies, damned lies, and MSIs */
+ if (dev->dev_flags & PCI_DEV_FLAGS_HAS_MSI_MASKING)
+ control |= PCI_MSI_FLAGS_MASKBIT;
entry->msi_attrib.is_msix = 0;
entry->msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index cd8aa6fce204..152a4d74f87f 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -233,6 +233,8 @@ enum pci_dev_flags {
PCI_DEV_FLAGS_NO_FLR_RESET = (__force pci_dev_flags_t) (1 << 10),
/* Don't use Relaxed Ordering for TLPs directed at this device */
PCI_DEV_FLAGS_NO_RELAXED_ORDERING = (__force pci_dev_flags_t) (1 << 11),
+ /* Device does honor MSI masking despite saying otherwise */
+ PCI_DEV_FLAGS_HAS_MSI_MASKING = (__force pci_dev_flags_t) (1 << 12),
};
enum pci_irq_reroute_variant {