hwtracing: hisi_ptt: Handle the interrupt in hardirq context
authorYicong Yang <yangyicong@hisilicon.com>
Tue, 10 Oct 2023 08:47:28 +0000 (16:47 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 20 Jan 2024 10:51:39 +0000 (11:51 +0100)
commit5e67b92b8b2b9b5bdd126bdfed49f7bdad09329a
tree7b0de4266d58f00de619d8f2223471dc86f89b6e
parenta4848c45a3f01d6af48ce0101b103fcb3f251ba1
hwtracing: hisi_ptt: Handle the interrupt in hardirq context

[ Upstream commit e0dd27ad8af00f147ac3c9de88e0687986afc3ea ]

Handle the trace interrupt in the hardirq context, make sure the irq
core won't threaded it by declaring IRQF_NO_THREAD and userspace won't
balance it by declaring IRQF_NOBALANCING. Otherwise we may violate the
synchronization requirements of the perf core, referenced to the
change of arm-ccn PMU
  commit 0811ef7e2f54 ("bus: arm-ccn: fix PMU interrupt flags").

In the interrupt handler we mainly doing 2 things:
- Copy the data from the local DMA buffer to the AUX buffer
- Commit the data in the AUX buffer

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
[ Fixed commit description to suppress checkpatch warning ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231010084731.30450-3-yangyicong@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/hwtracing/ptt/hisi_ptt.c