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[2/6] ntb_hw_switchtec: Fix bug with more than 32 partitions

Message ID 20211224012334.89173-3-kelvin.cao@microchip.com (mailing list archive)
State Handled Elsewhere
Delegated to: Bjorn Helgaas
Headers show
Series Switchtec NTB Fixes and Improvements | expand

Commit Message

Kelvin Cao Dec. 24, 2021, 1:23 a.m. UTC 
From: Wesley Sheng <wesley.sheng@microchip.com>

Switchtec could support as mush as 48 partitions, but ffs & fls are
for 32 bit argument, in case of partition index larger than 31, the
current code could not parse the peer partition index correctly.
Change to the 64 bit version __ffs64 & fls64 accordingly to fix this
bug.

Fixes: 3df54c870f52 ("ntb_hw_switchtec: Allow using Switchtec NTB in multi-partition setups")
Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com>
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
---
 drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
index 6603c77c0a84..ec9cb6c81eda 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -840,7 +840,6 @@  static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
 	u64 tpart_vec;
 	int self;
 	u64 part_map;
-	int bit;
 
 	sndev->ntb.pdev = sndev->stdev->pdev;
 	sndev->ntb.topo = NTB_TOPO_SWITCH;
@@ -861,29 +860,28 @@  static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
 	part_map = ioread64(&sndev->mmio_ntb->ep_map);
 	part_map &= ~(1 << sndev->self_partition);
 
-	if (!ffs(tpart_vec)) {
+	if (!tpart_vec) {
 		if (sndev->stdev->partition_count != 2) {
 			dev_err(&sndev->stdev->dev,
 				"ntb target partition not defined\n");
 			return -ENODEV;
 		}
 
-		bit = ffs(part_map);
-		if (!bit) {
+		if (!part_map) {
 			dev_err(&sndev->stdev->dev,
 				"peer partition is not NT partition\n");
 			return -ENODEV;
 		}
 
-		sndev->peer_partition = bit - 1;
+		sndev->peer_partition = __ffs64(part_map);
 	} else {
-		if (ffs(tpart_vec) != fls(tpart_vec)) {
+		if (__ffs64(tpart_vec) != (fls64(tpart_vec) - 1)) {
 			dev_err(&sndev->stdev->dev,
 				"ntb driver only supports 1 pair of 1-1 ntb mapping\n");
 			return -ENODEV;
 		}
 
-		sndev->peer_partition = ffs(tpart_vec) - 1;
+		sndev->peer_partition = __ffs64(tpart_vec);
 		if (!(part_map & (1ULL << sndev->peer_partition))) {
 			dev_err(&sndev->stdev->dev,
 				"ntb target partition is not NT partition\n");