From a632cb0b4013ff9ba8ce5f062a45e5652975a68b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 4 Nov 2021 18:01:29 +0000 Subject: [PATCH] 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 Signed-off-by: Thomas Gleixner Reviewed-by: Thomas Gleixner Link: https://lore.kernel.org/r/20211104180130.3825416-2-maz@kernel.org Cc: Bjorn Helgaas Signed-off-by: Greg Kroah-Hartman --- drivers/pci/msi.c | 3 +++ include/linux/pci.h | 2 ++ 2 files changed, 5 insertions(+) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index c824764f44ff7..d42c84a2d2eba 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -569,6 +569,9 @@ msi_setup_entry(struct pci_dev *dev, int nvec, const 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 6f9ca2f278b32..a4bbce871e08e 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -205,6 +205,8 @@ 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 { -- 2.51.0