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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 15:49:09 +0300
commit18c55aed17b2d9b34c8b4946bc7eeb0a51ce8d10 (patch)
tree80099f337314373cab30cc04b8209930ed0b4bcd
parentf64af173573104dd896a75b1b9116031b35bbb95 (diff)
downloadlinux-18c55aed17b2d9b34c8b4946bc7eeb0a51ce8d10.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 30bec2482e27..da5fbfcda433 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -585,6 +585,9 @@ 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 acbed2ecf6e8..25acd447c922 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -227,6 +227,8 @@ 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 {