microblaze: add loglvl to microblaze_unwind()

Currently, the log-level of show_stack() depends on a platform
realization. It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).

Furthermore, it forces the logic decision from user to an architecture
side. In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages. And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.

Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers. Also, it will consolidate
printings with headers.

Add log level parameter to microblaze_unwind() as a preparation to add
show_stack_loglvl().

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Simek <monstr@monstr.eu>
Link: http://lkml.kernel.org/r/20200418201944.482088-20-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

microblaze: Do not use module.h in files which are not modules

Based on the patch:
"lib: reduce the use of module.h wherever possible"
(sha1: 8bc3bcc93a2b4e47d5d410146f6546bca6171663)
fix all microblaze files which are not modules.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

microblaze: Add stack unwinder

Implement intelligent backtracing by searching for stack frame creation,
and emitting only return addresses. Use print_hex_dump() to display the
entire binary kernel stack.

Limitation: MMU kernels are not currently able to trace beyond a system trap
(interrupt, syscall, etc.). It is the intent of this patch to provide
infrastructure that can be extended to add this capability later.

Changes from V1:
* Removed checks in find_frame_creation() that prevented location of the frame
creation instruction in heavily optimized code
* Various formatting/commenting/file location tweaks per review comments
* Dropped Kconfig option to enable STACKTRACE as something logically separate

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>

microblaze: Stack trace support

This is working implemetation but the problem is that
Microblaze misses frame pointer that's why is there
big loop which trace and show all addresses which are in text.
It shows addresses which are in registers, etc.

This is problem and this is the reason why all Microblaze
traces are wrong. There is an option to do hacks and trace
the kernel code but this is too complicated.

Signed-off-by: Michal Simek <monstr@monstr.eu>