coresigh: Updates for v6.6

Coresight and hwtracing subsystem updates for Linux v6.6 includes:

 - ACPI support for CoreSight ETMv4x via system instructions and Arm ETE (v9.x).
 - Fix potential sleeping in atomic context for TRBE driver
 - Fix memory leak in ACPI platform parsing code
 - Fix all warnings with W=1
 - Fix warning with double free attempt for TRBE platform data
 - Miscellaneous cleanups and fixes

 Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
coresight: trbe: Fix TRBE potential sleep in atomic context

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
1 file changed