PCI/MSI: Do not set invalid bits in MSI mask

msi_mask_irq() takes a mask and a flags argument. The mask argument is used
to mask out bits from the cached mask and the flags argument to set bits.

Some places invoke it with a flags argument which sets bits which are not
used by the device, i.e. when the device supports up to 8 vectors a full
unmask in some places sets the mask to 0xFFFFFF00. While devices probably
do not care, it's still bad practice.

Fixes: 7ba1930db02f ("PCI MSI: Unmask MSI if setup failed")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210729222542.568173099@linutronix.de

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 434c704..e27ac6b 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -656,21 +656,21 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
        /* Configure MSI capability structure */
        ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
        if (ret) {
-               msi_mask_irq(entry, mask, ~mask);
+               msi_mask_irq(entry, mask, 0);
                free_msi_irqs(dev);
                return ret;
        }
 
        ret = msi_verify_entries(dev);
        if (ret) {
-               msi_mask_irq(entry, mask, ~mask);
+               msi_mask_irq(entry, mask, 0);
                free_msi_irqs(dev);
                return ret;
        }
 
        ret = populate_msi_sysfs(dev);
        if (ret) {
-               msi_mask_irq(entry, mask, ~mask);
+               msi_mask_irq(entry, mask, 0);
                free_msi_irqs(dev);
                return ret;
        }
@@ -962,7 +962,7 @@ static void pci_msi_shutdown(struct pci_dev *dev)
        /* Return the device with MSI unmasked as initial states */
        mask = msi_mask(desc->msi_attrib.multi_cap);
        /* Keep cached state to be restored */
-       __pci_msi_desc_mask_irq(desc, mask, ~mask);
+       __pci_msi_desc_mask_irq(desc, mask, 0);
 
        /* Restore dev->irq to its default pin-assertion IRQ */
        dev->irq = desc->msi_attrib.default_irq;