Junhao He 5fa1552877 coresight: trbe: Fix TRBE potential sleep in atomic context
[ Upstream commit c0a232f1e19e378c5c4e5973a996392942c80090 ]

smp_call_function_single() will allocate an IPI interrupt vector to
the target processor and send a function call request to the interrupt
vector. After the target processor receives the IPI interrupt, it will
execute arm_trbe_remove_coresight_cpu() call request in the interrupt
handler.

According to the device_unregister() stack information, if other process
is useing the device, the down_write() may sleep, and trigger deadlocks
or unexpected errors.

  arm_trbe_remove_coresight_cpu
    coresight_unregister
      device_unregister
        device_del
          kobject_del
            __kobject_del
              sysfs_remove_dir
                kernfs_remove
                  down_write ---------> it may sleep

Add a helper arm_trbe_disable_cpu() to disable TRBE precpu irq and reset
per TRBE.
Simply call arm_trbe_remove_coresight_cpu() directly without useing the
smp_call_function_single(), which is the same as registering the TRBE
coresight device.

Fixes: 3fbf7f011f24 ("coresight: sink: Add TRBE driver")
Signed-off-by: Junhao He <hejunhao3@huawei.com>
Link: https://lore.kernel.org/r/20230814093813.19152-2-hejunhao3@huawei.com
[ Remove duplicate cpumask checks during removal ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[ v3 - Remove the operation of assigning NULL to cpudata->drvdata ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230818084052.10116-1-hejunhao3@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-13 09:42:56 +02:00
..
2021-04-16 07:26:50 +02:00