PCI: Test INTx masking during enumeration, not at run-time
The test for INTx masking via PCI_COMMAND_INTX_DISABLE performed in
pci_intx_mask_supported() should be done before the device can be used.
This is to avoid writing PCI_COMMAND while the driver owns the device, in
case that has any effect on MSI/MSI-X interrupts.
Move the content of pci_intx_mask_supported() to pci_intx_mask_broken() and
call it from pci_setup_device().
The test result can be queried at any time later using the same
pci_intx_mask_supported() interface as before (though with changed
implementation), so callers (uio, vfio) should be unaffected.
Signed-off-by: Piotr Gregor <piotrgregor@rsyncme.org>
[bhelgaas: changelog, remove quirk check, remove locking, move
dev->broken_intx_masking assignment to caller]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 33c2b0b..4f0613d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -366,7 +366,7 @@ struct pci_dev {
unsigned int is_thunderbolt:1; /* Thunderbolt controller */
unsigned int __aer_firmware_first_valid:1;
unsigned int __aer_firmware_first:1;
- unsigned int broken_intx_masking:1;
+ unsigned int broken_intx_masking:1; /* INTx masking can't be used */
unsigned int io_window_1k:1; /* Intel P2P bridge 1K I/O windows */
unsigned int irq_managed:1;
unsigned int has_secondary_link:1;
@@ -1003,6 +1003,15 @@ int __must_check pci_reenable_device(struct pci_dev *);
int __must_check pcim_enable_device(struct pci_dev *pdev);
void pcim_pin_device(struct pci_dev *pdev);
+static inline bool pci_intx_mask_supported(struct pci_dev *pdev)
+{
+ /*
+ * INTx masking is supported if PCI_COMMAND_INTX_DISABLE is
+ * writable and no quirk has marked the feature broken.
+ */
+ return !pdev->broken_intx_masking;
+}
+
static inline int pci_is_enabled(struct pci_dev *pdev)
{
return (atomic_read(&pdev->enable_cnt) > 0);
@@ -1026,7 +1035,6 @@ int __must_check pci_set_mwi(struct pci_dev *dev);
int pci_try_set_mwi(struct pci_dev *dev);
void pci_clear_mwi(struct pci_dev *dev);
void pci_intx(struct pci_dev *dev, int enable);
-bool pci_intx_mask_supported(struct pci_dev *dev);
bool pci_check_and_mask_intx(struct pci_dev *dev);
bool pci_check_and_unmask_intx(struct pci_dev *dev);
int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask);