linux-toradex.git/arch/powerpc/kernel/udbg.c, branch v6.7

powerpc: Add support for early debugging via Serial 16550 console

2022-09-28T09:22:09+00:00

Currently powerpc early debugging contains lot of platform specific
options, but does not support standard UART / serial 16550 console.

Later legacy_serial.c code supports registering UART as early debug console
from device tree but it is not early during booting, but rather later after
machine description code finishes.

So for real early debugging via UART is current code unsuitable.

Add support for new early debugging option CONFIG_PPC_EARLY_DEBUG_16550
which enable Serial 16550 console on address defined by new option
CONFIG_PPC_EARLY_DEBUG_16550_PHYSADDR and by stride by option
CONFIG_PPC_EARLY_DEBUG_16550_STRIDE.

With this change it is possible to debug powerpc machine descriptor code.
For example this early debugging code can print on serial console also
"No suitable machine description found" error which is done before
legacy_serial.c code.

Signed-off-by: Pali Rohár 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220822231501.16827-1-pali@kernel.org

isystem: ship and use stdarg.h

2021-08-19T00:02:55+00:00

Ship minimal stdarg.h (1 type, 4 macros) as .
stdarg.h is the only userspace header commonly used in the kernel.

GPL 2 version of  can be extracted from
http://archive.debian.org/debian/pool/main/g/gcc-4.2/gcc-4.2_4.2.4.orig.tar.gz

Signed-off-by: Alexey Dobriyan 
Acked-by: Rafael J. Wysocki 
Acked-by: Ard Biesheuvel 
Signed-off-by: Masahiro Yamada

powerpc/udbg: Make it safe to call udbg_printf() always

2019-10-11T08:33:25+00:00

Make udbg_printf() check if udbg_putc is set, and if not just return.
This makes it safe to call udbg_printf() anytime, even when a udbg
backend has not been registered, which means we can avoid some ifdefs
at call sites.

Signed-off-by: Qian Cai 
[mpe: Split out of larger patch, write change log]
Signed-off-by: Michael Ellerman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

powerpc: use a CONSOLE_LOGLEVEL_DEBUG macro

2019-01-14T09:39:27+00:00

Use a CONSOLE_LOGLEVEL_DEBUG macro for console_loglevel rather
than a naked number.

Signed-off-by: Sergey Senozhatsky 
Signed-off-by: Michael Ellerman

powerpc: Remove the celleb support

2015-04-07T07:15:13+00:00

The celleb code has seen no actual development for ~7 years.

We (maintainers) have no access to test hardware, and it is highly
likely the code has bit-rotted.

As far as we're aware the hardware was never widely available, and is
certainly no longer available, and no one on the list has shown any
interest in it over the years.

So remove it. If anyone has one and cares please speak up.

Signed-off-by: Michael Ellerman 
Acked-by: Benjamin Herrenschmidt 
Acked-by: Jeremy Kerr

powerpc: Remove platforms/wsp and associated pieces

2014-06-11T06:35:38+00:00

__attribute__ ((unused))

WSP is the last user of CONFIG_PPC_A2, so we remove that as well.

Although CONFIG_PPC_ICSWX still exists, it's no longer selectable for
any Book3E platform, so we can remove the code in mmu-book3e.h that
depended on it.

Signed-off-by: Michael Ellerman 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Add a configuration option for early BootX/OpenFirmware debug

2013-06-20T06:55:12+00:00

Signed-off-by: Alistair Popple 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Add an in memory udbg console

2013-05-07T20:36:49+00:00

This patch adds a new udbg early debug console which utilises
statically defined input and output buffers stored within the kernel
BSS. It is primarily designed to assist with bring up of new hardware
which may not have a working console but which has a method of
reading/writing kernel memory.

This version incorporates comments made by Ben H (thanks!).

Changes from v1:
	- Add memory barriers.
	- Ensure updating of read/write positions is atomic.

Signed-off-by: Alistair Popple 
Signed-off-by: Benjamin Herrenschmidt

early_printk: consolidate random copies of identical code

2013-04-30T01:28:13+00:00

The early console implementations are the same all over the place.  Move
the print function to kernel/printk and get rid of the copies.

[akpm@linux-foundation.org: arch/mips/kernel/early_printk.c needs kernel.h for va_list]
[paul.gortmaker@windriver.com: sh4: make the bios early console support depend on EARLY_PRINTK]
Signed-off-by: Thomas Gleixner 
Signed-off-by: Paul Gortmaker 
Cc: Russell King 
Acked-by: Mike Frysinger 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mundt 
Cc: "David S. Miller" 
Cc: Chris Metcalf 
Cc: Richard Weinberger 
Reviewed-by: Ingo Molnar 
Tested-by: Paul Gortmaker 
Cc: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds