linux

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Peter Oberparleiter d72541f945 s390/debug: add early tracing support

Debug areas can currently only be used after s390dbf initialization
which occurs as a postcore_initcall. This is too late for tracing
earlier code such as that related to console_init().

This patch introduces a macro for defining a statically initialized
debug area that can be used to trace very early code. The macro is made
available for built-in code only because modules are never running
during early boot.

Example usage:

1. Define static debug area:

  DEFINE_STATIC_DEBUG_INFO(my_debug, "my_debug", 4, 1, 16,
			   &debug_hex_ascii_view);

2. Add trace entry:

  debug_event(&my_debug, 0, "DATA", 4);

Note: The debug area is automatically registered in debugfs during boot.
      A driver must not call any of the debug_register()/_unregister()
      functions on a static debug_info_t!

Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

2021-08-25 11:03:35 +02:00

alpha

Kbuild updates for v5.14

2021-07-10 11:01:38 -07:00

arc

Kbuild updates for v5.14

2021-07-10 11:01:38 -07:00

arm

ARM: SoC fixes for v5.14

2021-07-17 15:58:24 -07:00

arm64

USB fixes for 5.14-rc3