Re: [PATCH] selftest: drivers: Add support to check duplicate hwirq

[Shuah Khan <skhan@linuxfoundation.org>]

On 10/17/24 22:29, Joseph Jang wrote:
> 
> 
> On 2024/9/4 9:44 AM, Joseph Jang wrote:
>> Validate there are no duplicate hwirq from the irq debug
>> file system /sys/kernel/debug/irq/irqs/* per chip name.
>>
>> One example log show 2 duplicated hwirq in the irq debug
>> file system.
>>
>> $ sudo cat /sys/kernel/debug/irq/irqs/163
>> handler:  handle_fasteoi_irq
>> device:   0019:00:00.0
>>       <SNIP>
>> node:     1
>> affinity: 72-143
>> effectiv: 76
>> domain:  irqchip@0x0000100022040000-3
>>   hwirq:   0xc8000000
>>   chip:    ITS-MSI
>>    flags:   0x20
>>
>> $ sudo cat /sys/kernel/debug/irq/irqs/174
>> handler:  handle_fasteoi_irq
>> device:   0039:00:00.0
>>      <SNIP>
>> node:     3
>> affinity: 216-287
>> effectiv: 221
>> domain:  irqchip@0x0000300022040000-3
>>   hwirq:   0xc8000000
>>   chip:    ITS-MSI
>>    flags:   0x20
>>
>> The irq-check.sh can help to collect hwirq and chip name from
>> /sys/kernel/debug/irq/irqs/* and print error log when find duplicate
>> hwirq per chip name.
>>
>> Kernel patch ("PCI/MSI: Fix MSI hwirq truncation") [1] fix above issue.
>> [1]: https://lore.kernel.org/all/20240115135649.708536-1-vidyas@nvidia.com/
>>
>> Signed-off-by: Joseph Jang <jjang@nvidia.com>
>> Reviewed-by: Matthew R. Ochs <mochs@nvidia.com>
>> ---
>>   tools/testing/selftests/drivers/irq/Makefile  |  5 +++
>>   tools/testing/selftests/drivers/irq/config    |  2 +
>>   .../selftests/drivers/irq/irq-check.sh        | 39 +++++++++++++++++++
>>   3 files changed, 46 insertions(+)
>>   create mode 100644 tools/testing/selftests/drivers/irq/Makefile
>>   create mode 100644 tools/testing/selftests/drivers/irq/config
>>   create mode 100755 tools/testing/selftests/drivers/irq/irq-check.sh
>>
>> diff --git a/tools/testing/selftests/drivers/irq/Makefile b/tools/testing/selftests/drivers/irq/Makefile
>> new file mode 100644
>> index 000000000000..d6998017c861
>> --- /dev/null
>> +++ b/tools/testing/selftests/drivers/irq/Makefile
>> @@ -0,0 +1,5 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +
>> +TEST_PROGS := irq-check.sh
>> +
>> +include ../../lib.mk
>> diff --git a/tools/testing/selftests/drivers/irq/config b/tools/testing/selftests/drivers/irq/config
>> new file mode 100644
>> index 000000000000..a53d3b713728
>> --- /dev/null
>> +++ b/tools/testing/selftests/drivers/irq/config
>> @@ -0,0 +1,2 @@
>> +CONFIG_GENERIC_IRQ_DEBUGFS=y
>> +CONFIG_GENERIC_IRQ_INJECTION=y
>> diff --git a/tools/testing/selftests/drivers/irq/irq-check.sh b/tools/testing/selftests/drivers/irq/irq-check.sh
>> new file mode 100755
>> index 000000000000..e784777043a1
>> --- /dev/null
>> +++ b/tools/testing/selftests/drivers/irq/irq-check.sh
>> @@ -0,0 +1,39 @@
>> +#!/bin/bash
>> +# SPDX-License-Identifier: GPL-2.0
>> +
>> +# This script need root permission
>> +uid=$(id -u)
>> +if [ $uid -ne 0 ]; then
>> +    echo "SKIP: Must be run as root"
>> +    exit 4
>> +fi
>> +
>> +# Ensure debugfs is mounted
>> +mount -t debugfs nodev /sys/kernel/debug 2>/dev/null
>> +if [ ! -d "/sys/kernel/debug/irq/irqs" ]; then
>> +    echo "SKIP: irq debugfs not found"
>> +    exit 4
>> +fi
>> +
>> +# Traverse the irq debug file system directory to collect chip_name and hwirq
>> +hwirq_list=$(for irq_file in /sys/kernel/debug/irq/irqs/*; do
>> +    # Read chip name and hwirq from the irq_file
>> +    chip_name=$(cat "$irq_file" | grep -m 1 'chip:' | awk '{print $2}')
>> +    hwirq=$(cat "$irq_file" | grep -m 1 'hwirq:' | awk '{print $2}' )
>> +
>> +    if [ -z "$chip_name" ] || [ -z "$hwirq" ]; then
>> +        continue
>> +    fi
>> +
>> +    echo "$chip_name $hwirq"
>> +done)
>> +
>> +dup_hwirq_list=$(echo "$hwirq_list" | sort | uniq -cd)
>> +
>> +if [ -n "$dup_hwirq_list" ]; then
>> +    echo "ERROR: Found duplicate hwirq"
>> +    echo "$dup_hwirq_list"
>> +    exit 1
>> +fi
>> +
>> +exit 0
> 
> Hi Tglx,
> 
> I follow your suggestions https://www.mail-archive.com/linux-kselftest@vger.kernel.org/msg16952.html to enable IRQ DEBUG_FS and create a new script to scan duplicated hwirq. If you have available time, would you please help to take a look at new patch again ?
> 
> 
> https://lore.kernel.org/all/20240904014426.3404397-1-jjang@nvidia.com/T/
> 
> 
> Hi Shuah,
> 
> If you have time, could you help to take a look at the new patch ?
> 

Once Thomas reviews this and gives me okay - I will accept the patch.

thanks,
-- Shuah