[PATCH v2] PCI: Mark broken INTx masking for Mellanox devices

[Gavin Shan <gwshan@linux.vnet.ibm.com>]

The VFIO driver is routing LSI interrupts by capturing, masking,
and then delivering. When passing though Mallanox adapters from
host to guest, interrupt storm was reported from host and guest.
That's because we can't mask the LSI interrupt with help of PCI
command register.

[root@ncc-1701 ~]# lspci | grep Mellanox
0001:05:00.0 Ethernet controller: Mellanox Technologies MT27500 \
             Family [ConnectX-3]
0005:01:00.0 Ethernet controller: Mellanox Technologies MT26448 \
             [ConnectX EN 10GigE, PCIe 2.0 5GT/s] (rev b0)

The patch marks broken INTx masking for Mellanox devices so that
the VFIO driver will always mask the interrupt from interrupt
controller side to avoid interrupt storm.

Cc: Amir Vadai <amirv@mellanox.com>
Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
 drivers/pci/quirks.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index d0f6926..8c2b96f 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2977,6 +2977,10 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, 0x0030,
 			 quirk_broken_intx_masking);
 DECLARE_PCI_FIXUP_HEADER(0x1814, 0x0601, /* Ralink RT2800 802.11n PCI */
 			 quirk_broken_intx_masking);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, 0x1003,
+			 quirk_broken_intx_masking);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, 0x6750,
+			 quirk_broken_intx_masking);
 /*
  * Realtek RTL8169 PCI Gigabit Ethernet Controller (rev 10)
  * Subsystem: Realtek RTL8169/8110 Family PCI Gigabit Ethernet NIC
-- 
1.8.3.2