PCI/MSI: Set device flag indicating only 32-bit MSI support
authorVidya Sagar <vidyas@nvidia.com>
Thu, 3 Dec 2020 18:51:10 +0000 (12:51 -0600)
committerBjorn Helgaas <bhelgaas@google.com>
Fri, 4 Dec 2020 18:17:04 +0000 (12:17 -0600)
commit2053230af11dc651ee3024682df12668496adad2
tree18d930b9f83c6ce0b56e26ba4ce54cf5aca9e33a
parent830dfe88ea37881cbb7d390e90b45611929d5943
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>
drivers/pci/msi.c