[PATCH 5/5] PCI/switchtec: Add check of event support

[<kelvin.cao@microchip.com>]

From: Logan Gunthorpe <logang@deltatee.com>

Not all events are supported by every gen/variant of the Switchtec
firmware. To solve this, since Gen4, a new bit in each event header
is introduced to indicate if an event is supported by the firmware.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
---
 drivers/pci/switch/switchtec.c | 8 +++++++-
 include/linux/switchtec.h      | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c
index 20cec2367084..739e063a6b85 100644
--- a/drivers/pci/switch/switchtec.c
+++ b/drivers/pci/switch/switchtec.c
@@ -1016,6 +1016,9 @@ static int event_ctl(struct switchtec_dev *stdev,
 		return PTR_ERR(reg);
 
 	hdr = ioread32(reg);
+	if (hdr & SWITCHTEC_EVENT_NOT_SUPP)
+		return -EOPNOTSUPP;
+
 	for (i = 0; i < ARRAY_SIZE(ctl->data); i++)
 		ctl->data[i] = ioread32(&reg[i + 1]);
 
@@ -1088,7 +1091,7 @@ static int ioctl_event_ctl(struct switchtec_dev *stdev,
 		for (ctl.index = 0; ctl.index < nr_idxs; ctl.index++) {
 			ctl.flags = event_flags;
 			ret = event_ctl(stdev, &ctl);
-			if (ret < 0)
+			if (ret < 0 && ret != -EOPNOTSUPP)
 				return ret;
 		}
 	} else {
@@ -1395,6 +1398,9 @@ static int mask_event(struct switchtec_dev *stdev, int eid, int idx)
 	hdr_reg = event_regs[eid].map_reg(stdev, off, idx);
 	hdr = ioread32(hdr_reg);
 
+	if (hdr & SWITCHTEC_EVENT_NOT_SUPP)
+		return 0;
+
 	if (!(hdr & SWITCHTEC_EVENT_OCCURRED && hdr & SWITCHTEC_EVENT_EN_IRQ))
 		return 0;
 
diff --git a/include/linux/switchtec.h b/include/linux/switchtec.h
index 082f1d51957a..be24056ac00f 100644
--- a/include/linux/switchtec.h
+++ b/include/linux/switchtec.h
@@ -19,6 +19,7 @@
 #define SWITCHTEC_EVENT_EN_CLI   BIT(2)
 #define SWITCHTEC_EVENT_EN_IRQ   BIT(3)
 #define SWITCHTEC_EVENT_FATAL    BIT(4)
+#define SWITCHTEC_EVENT_NOT_SUPP BIT(31)
 
 #define SWITCHTEC_DMA_MRPC_EN	BIT(0)
 
-- 
2.25.1