[PATCH] PCI/MSI: Set device flag indicating only 32-bit MSI support

From: Vidya Sagar
Date: Tue Nov 17 2020 - 09:57:59 EST


There are devices (Ex:- Marvell SATA controller) that don't support
64-bit MSIs and the same is advertised through their MSI capability
register. Set no_64bit_msi flag explicitly for such devices in the
MSI setup code so that the msi_verify_entries() API would catch
if the MSI arch code tries to use 64-bit MSI.

Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
---
drivers/pci/msi.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d52d118979a6..af49da28854e 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -581,10 +581,12 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));

- if (control & PCI_MSI_FLAGS_64BIT)
+ if (control & PCI_MSI_FLAGS_64BIT) {
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
- else
+ } else {
entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
+ dev->no_64bit_msi = 1;
+ }

/* Save the initial mask status */
if (entry->msi_attrib.maskbit)
--
2.17.1