[PATCH 1/1] selftest: drivers: Add support its msi hwirq checking

[Joseph Jang <jjang@nvidia.com>]

Validate there are no duplicate ITS-MSI hwirqs from the
/sys/kernel/irq/*/hwirq.

One example log show 2 duplicated MSI entries in the /proc/interrupts.

150: 0 ... ITS-MSI 3355443200 Edge      pciehp
152: 0 ... ITS-MSI 3355443200 Edge      pciehp

Kernel patch ("PCI/MSI: Fix MSI hwirq truncation") [1] fix above issue.
[1]: https://lore.kernel.org/all/20240115135649.708536-1-vidyas@nvidia.com/

Reviewed-by: Matthew R. Ochs <mochs@nvidia.com>
Signed-off-by: Joseph Jang <jjang@nvidia.com>
---
 tools/testing/selftests/drivers/irq/Makefile  |  5 +++++
 .../selftests/drivers/irq/its-msi-irq-test.sh | 20 +++++++++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 tools/testing/selftests/drivers/irq/Makefile
 create mode 100755 tools/testing/selftests/drivers/irq/its-msi-irq-test.sh

diff --git a/tools/testing/selftests/drivers/irq/Makefile b/tools/testing/selftests/drivers/irq/Makefile
new file mode 100644
index 000000000000..569df5de22ee
--- /dev/null
+++ b/tools/testing/selftests/drivers/irq/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
+TEST_PROGS := its-msi-irq-test.sh
+
+include ../../lib.mk
diff --git a/tools/testing/selftests/drivers/irq/its-msi-irq-test.sh b/tools/testing/selftests/drivers/irq/its-msi-irq-test.sh
new file mode 100755
index 000000000000..87c88674903f
--- /dev/null
+++ b/tools/testing/selftests/drivers/irq/its-msi-irq-test.sh
@@ -0,0 +1,20 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+if [ -z "$(grep "ITS-MSI" /proc/interrupts)" ]; then
+	echo "SKIP: no ITS-MSI irq."
+	exit 4
+fi
+
+# Get ITS-MSI hwirq list from /sys/kernel/irq/*/hwirq.
+its_msi_irq_list=$(grep "ITS-MSI" /sys/kernel/irq/*/chip_name |
+				   awk -F ':' '{print $1}' |
+				   xargs -I {} sh -c 'cat $(dirname {})/hwirq' | sort -V)
+
+# Check whether could find duplicated its-msi hwirq or not.
+if [ -n "$(echo "$its_msi_irq_list" | uniq -cd)" ]; then
+	echo "ERROR: find duplicated its-msi hwirq."
+	exit 1
+fi
+
+exit 0
-- 
2.34.1