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| author | Vidya Sagar <vidyas@nvidia.com> | 2020-12-03 12:51:10 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2020-12-04 12:17:04 -0600 |
| commit | 2053230af11dc651ee3024682df12668496adad2 (patch) | |
| tree | 18d930b9f83c6ce0b56e26ba4ce54cf5aca9e33a /drivers/pci/msi.c | |
| parent | 830dfe88ea37881cbb7d390e90b45611929d5943 (diff) | |
| download | lwn-2053230af11dc651ee3024682df12668496adad2.tar.gz lwn-2053230af11dc651ee3024682df12668496adad2.zip | |
PCI/MSI: Set device flag indicating only 32-bit MSI support
The MSI-X Capability requires devices to support 64-bit Message Addresses,
but the MSI Capability can support either 32- or 64-bit addresses.
Previously, we set dev->no_64bit_msi for a few broken devices that
advertise 64-bit MSI support but don't correctly support it.
In addition, check the MSI "64-bit Address Capable" bit for all devices and
set dev->no_64bit_msi for devices that don't advertise 64-bit support.
This allows msi_verify_entries() to catch arch code defects that assign
64-bit addresses when they're not supported.
The warning is helpful to find defects like the one fixed by
https://lore.kernel.org/r/20201117165312.25847-1-vidyas@nvidia.com
[bhelgaas: set no_64bit_msi in pci_msi_init(), commit log]
Link: https://lore.kernel.org/r/20201124105035.24573-1-vidyas@nvidia.com
Link: https://lore.kernel.org/r/20201203185110.1583077-4-helgaas@kernel.org
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/pci/msi.c')
| -rw-r--r-- | drivers/pci/msi.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 4c41e9ac62ec..3162f88fe940 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -623,11 +623,11 @@ static int msi_verify_entries(struct pci_dev *dev) struct msi_desc *entry; for_each_pci_msi_entry(entry, dev) { - if (!dev->no_64bit_msi || !entry->msg.address_hi) - continue; - pci_err(dev, "Device has broken 64-bit MSI but arch" - " tried to assign one above 4G\n"); - return -EIO; + if (entry->msg.address_hi && dev->no_64bit_msi) { + pci_err(dev, "arch assigned 64-bit MSI address %#x%08x but device only supports 32 bits\n", + entry->msg.address_hi, entry->msg.address_lo); + return -EIO; + } } return 0; } @@ -1619,6 +1619,9 @@ void pci_msi_init(struct pci_dev *dev) if (ctrl & PCI_MSI_FLAGS_ENABLE) pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, ctrl & ~PCI_MSI_FLAGS_ENABLE); + + if (!(ctrl & PCI_MSI_FLAGS_64BIT)) + dev->no_64bit_msi = 1; } void pci_msix_init(struct pci_dev *dev) |