linux-toradex.git/arch/powerpc/Kconfig.debug, branch v3.1 Linux kernel for Apalis and Colibri modules powerpc/pseries: Re-implement HVSI as part of hvc_vio 2011-06-29T07:48:35+00:00 Benjamin Herrenschmidt benh@kernel.crashing.org 2011-05-12T03:46:38+00:00 4d2bb3f5003617cb42b89faefd0009c505c3abd5 On pseries machines, consoles are provided by the hypervisor using a low level get_chars/put_chars type interface. However, this is really just a transport to the service processor which implements them either as "raw" console (networked consoles, HMC, ...) or as "hvsi" serial ports. The later is a simple packet protocol on top of the raw character interface that is supposed to convey additional "serial port" style semantics. In practice however, all it does is provide a way to read the CD line and set/clear our DTR line, that's it. We currently implement the "raw" protocol as an hvc console backend (/dev/hvcN) and the "hvsi" protocol using a separate tty driver (/dev/hvsi0). However this is quite impractical. The arbitrary difference between the two type of devices has been a major source of user (and distro) confusion. Additionally, there's an additional mini -hvsi implementation in the pseries platform code for our low level debug console and early boot kernel messages, which means code duplication, though that low level variant is impractical as it's incapable of doing the initial protocol negociation to establish the link to the FSP. This essentially replaces the dedicated hvsi driver and the platform udbg code completely by extending the existing hvc_vio backend used in "raw" mode so that: - It now supports HVSI as well - We add support for hvc backend providing tiocm{get,set} - It also provides a udbg interface for early debug and boot console This is overall less code, though this will only be obvious once we remove the old "hvsi" driver, which is still available for now. When the old driver is enabled, the new code still kicks in for the low level udbg console, replacing the old mini implementation in the platform code, it just doesn't provide the higher level "hvc" interface. In addition to producing generally simler code, this has several benefits over our current situation: - The user/distro only has to deal with /dev/hvcN for the hypervisor console, avoiding all sort of confusion that has plagued us in the past - The tty, kernel and low level debug console all use the same code base which supports the full protocol establishment process, thus the console is now available much earlier than it used to be with the old HVSI driver. The kernel console works much earlier and udbg is available much earlier too. Hackers can enable a hard coded very-early debug console as well that works with HVSI (previously that was only supported for the "raw" mode). I've tried to keep the same semantics as hvsi relative to how I react to things like CD changes, with some subtle differences though: - I clear DTR on close if HUPCL is set - Current hvsi triggers a hangup if it detects a up->down transition on CD (you can still open a console with CD down). My new implementation triggers a hangup if the link to the FSP is severed, and severs it upon detecting a up->down transition on CD. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> 
On pseries machines, consoles are provided by the hypervisor using
a low level get_chars/put_chars type interface. However, this is
really just a transport to the service processor which implements
them either as "raw" console (networked consoles, HMC, ...) or as
"hvsi" serial ports.

The later is a simple packet protocol on top of the raw character
interface that is supposed to convey additional "serial port" style
semantics. In practice however, all it does is provide a way to
read the CD line and set/clear our DTR line, that's it.

We currently implement the "raw" protocol as an hvc console backend
(/dev/hvcN) and the "hvsi" protocol using a separate tty driver
(/dev/hvsi0).

However this is quite impractical. The arbitrary difference between
the two type of devices has been a major source of user (and distro)
confusion. Additionally, there's an additional mini -hvsi implementation
in the pseries platform code for our low level debug console and early
boot kernel messages, which means code duplication, though that low
level variant is impractical as it's incapable of doing the initial
protocol negociation to establish the link to the FSP.

This essentially replaces the dedicated hvsi driver and the platform
udbg code completely by extending the existing hvc_vio backend used
in "raw" mode so that:

 - It now supports HVSI as well
 - We add support for hvc backend providing tiocm{get,set}
 - It also provides a udbg interface for early debug and boot console

This is overall less code, though this will only be obvious once we
remove the old "hvsi" driver, which is still available for now. When
the old driver is enabled, the new code still kicks in for the low
level udbg console, replacing the old mini implementation in the platform
code, it just doesn't provide the higher level "hvc" interface.

In addition to producing generally simler code, this has several benefits
over our current situation:

 - The user/distro only has to deal with /dev/hvcN for the hypervisor
console, avoiding all sort of confusion that has plagued us in the past

 - The tty, kernel and low level debug console all use the same code
base which supports the full protocol establishment process, thus the
console is now available much earlier than it used to be with the
old HVSI driver. The kernel console works much earlier and udbg is
available much earlier too. Hackers can enable a hard coded very-early
debug console as well that works with HVSI (previously that was only
supported for the "raw" mode).

I've tried to keep the same semantics as hvsi relative to how I react
to things like CD changes, with some subtle differences though:

 - I clear DTR on close if HUPCL is set

 - Current hvsi triggers a hangup if it detects a up->down transition
   on CD (you can still open a console with CD down). My new implementation
   triggers a hangup if the link to the FSP is severed, and severs it upon
   detecting a up->down transition on CD.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
lib: consolidate DEBUG_STACK_USAGE option 2011-05-25T15:39:54+00:00 Stephen Boyd sboyd@codeaurora.org 2011-05-25T00:13:36+00:00 5ca43f6c3b365024d889bc77064bb331f5a72a45 Most arches define CONFIG_DEBUG_STACK_USAGE exactly the same way. Move it to lib/Kconfig.debug so each arch doesn't have to define it. This obviously makes the option generic, but that's fine because the config is already used in generic code. It's not obvious to me that sysrq-P actually does anything caution by keeping the most inclusive wording. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Richard Weinberger <richard@nod.at> Acked-by: Mike Frysinger <vapier@gentoo.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Hirokazu Takata <takata@linux-m32r.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Most arches define CONFIG_DEBUG_STACK_USAGE exactly the same way.  Move it
to lib/Kconfig.debug so each arch doesn't have to define it.  This
obviously makes the option generic, but that's fine because the config is
already used in generic code.

It's not obvious to me that sysrq-P actually does anything caution by
keeping the most inclusive wording.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib: consolidate DEBUG_PER_CPU_MAPS 2011-05-25T15:39:53+00:00 Stephen Boyd sboyd@codeaurora.org 2011-05-25T00:13:32+00:00 44ec7abe359204cc9186e32d31ef5b34c8d17274 DEBUG_PER_CPU_MAPS is used in lib/cpumask.c as well as in inlcude/linux/cpumask.h and thus it has outgrown its use within x86 and powerpc alone. Any arch with SMP support may want to get some more debugging, so make this option generic. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: <linux-arch@vger.kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
DEBUG_PER_CPU_MAPS is used in lib/cpumask.c as well as in
inlcude/linux/cpumask.h and thus it has outgrown its use within x86 and
powerpc alone.  Any arch with SMP support may want to get some more
debugging, so make this option generic.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: <linux-arch@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
powerpc: Add early debug for WSP platforms 2011-05-06T03:32:41+00:00 Jack Miller jack@codezen.org 2011-04-14T22:32:08+00:00 a0496d450ab8c17f6c4d86979b1f6ba486fe9365 Signed-off-by: Jack Miller <jack@codezen.org> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> 
Signed-off-by: Jack Miller <jack@codezen.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
powerpc: Unconditionally enabled irq stacks 2010-06-15T05:02:37+00:00 Christoph Hellwig hch@lst.de 2010-06-02T22:24:26+00:00 f1ba9a5b2ab7d3f5a910d93371c4f22b636b7683 Irq stacks provide an essential protection from stack overflows through external interrupts, at the cost of two additionals stacks per CPU. Enable them unconditionally to simplify the kernel build and prevent people from accidentally disabling them. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> 
Irq stacks provide an essential protection from stack overflows through
external interrupts, at the cost of two additionals stacks per CPU.

Enable them unconditionally to simplify the kernel build and prevent
people from accidentally disabling them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
powerpc/cpumask: Add DEBUG_PER_CPU_MAPS option 2010-05-06T08:05:26+00:00 Anton Blanchard anton@samba.org 2010-04-26T15:32:46+00:00 ceba1abcb00b0ef0b1efcd715285f6e05523edef Enable the DEBUG_PER_CPU_MAPS option so we can look for problems with cpumasks . Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> 
Enable the DEBUG_PER_CPU_MAPS option so we can look for problems with
cpumasks .

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Merge branch 'next' of git://git.secretlab.ca/git/linux-2.6 2009-12-16T21:26:53+00:00 Linus Torvalds torvalds@linux-foundation.org 2009-12-16T21:26:53+00:00 a73611b6aafa3b902524dad2d68e378c4ec9f4db * 'next' of git://git.secretlab.ca/git/linux-2.6: (23 commits) powerpc: fix up for mmu_mapin_ram api change powerpc: wii: allow ioremap within the memory hole powerpc: allow ioremap within reserved memory regions wii: use both mem1 and mem2 as ram wii: bootwrapper: add fixup to calc useable mem2 powerpc: gamecube/wii: early debugging using usbgecko powerpc: reserve fixmap entries for early debug powerpc: wii: default config powerpc: wii: platform support powerpc: wii: hollywood interrupt controller support powerpc: broadway processor support powerpc: wii: bootwrapper bits powerpc: wii: device tree powerpc: gamecube: default config powerpc: gamecube: platform support powerpc: gamecube/wii: flipper interrupt controller support powerpc: gamecube/wii: udbg support for usbgecko powerpc: gamecube/wii: do not include PCI support powerpc: gamecube/wii: declare as non-coherent platforms powerpc: gamecube/wii: introduce GAMECUBE_COMMON ... Fix up conflicts in arch/powerpc/mm/fsl_booke_mmu.c. Hopefully even close to correctly. 
* 'next' of git://git.secretlab.ca/git/linux-2.6: (23 commits)
  powerpc: fix up for mmu_mapin_ram api change
  powerpc: wii: allow ioremap within the memory hole
  powerpc: allow ioremap within reserved memory regions
  wii: use both mem1 and mem2 as ram
  wii: bootwrapper: add fixup to calc useable mem2
  powerpc: gamecube/wii: early debugging using usbgecko
  powerpc: reserve fixmap entries for early debug
  powerpc: wii: default config
  powerpc: wii: platform support
  powerpc: wii: hollywood interrupt controller support
  powerpc: broadway processor support
  powerpc: wii: bootwrapper bits
  powerpc: wii: device tree
  powerpc: gamecube: default config
  powerpc: gamecube: platform support
  powerpc: gamecube/wii: flipper interrupt controller support
  powerpc: gamecube/wii: udbg support for usbgecko
  powerpc: gamecube/wii: do not include PCI support
  powerpc: gamecube/wii: declare as non-coherent platforms
  powerpc: gamecube/wii: introduce GAMECUBE_COMMON
  ...

Fix up conflicts in arch/powerpc/mm/fsl_booke_mmu.c.

Hopefully even close to correctly.
powerpc: gamecube/wii: early debugging using usbgecko 2009-12-13T05:24:31+00:00 Albert Herranz albert_herranz@yahoo.es 2009-12-12T06:31:51+00:00 d1d56f8c1d5a622228177eca47e9dcff0498bddb Add support for using the USB Gecko adapter as an early debugging console on the Nintendo GameCube and Wii video game consoles. The USB Gecko is a 3rd party memory card interface adapter that provides a EXI (External Interface) to USB serial converter. Signed-off-by: Albert Herranz <albert_herranz@yahoo.es> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> 
Add support for using the USB Gecko adapter as an early debugging
console on the Nintendo GameCube and Wii video game consoles.
The USB Gecko is a 3rd party memory card interface adapter that provides
a EXI (External Interface) to USB serial converter.

Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
powerpc: tracing: Add hypervisor call tracepoints 2009-10-28T05:13:04+00:00 Anton Blanchard anton@samba.org 2009-10-26T18:50:29+00:00 c8cd093a6e9f96ea6b871576fd4e46d7c818bb89 Add hcall_entry and hcall_exit tracepoints. This replaces the inline assembly HCALL_STATS code and converts it to use the new tracepoints. To keep the disabled case as quick as possible, we embed a status word in the TOC so we can get at it with a single load. By doing so we keep the overhead at a minimum. Time taken for a null hcall: No tracepoint code: 135.79 cycles Disabled tracepoints: 137.95 cycles For reference, before this patch enabling HCALL_STATS resulted in a null hcall of 201.44 cycles! Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org> 
Add hcall_entry and hcall_exit tracepoints.  This replaces the inline
assembly HCALL_STATS code and converts it to use the new tracepoints.

To keep the disabled case as quick as possible, we embed a status word
in the TOC so we can get at it with a single load.  By doing so we
keep the overhead at a minimum.  Time taken for a null hcall:

No tracepoint code:	135.79 cycles
Disabled tracepoints:	137.95 cycles

For reference, before this patch enabling HCALL_STATS resulted in a null
hcall of 201.44 cycles!

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
powerpc: Add configurable -Werror for arch/powerpc 2009-06-16T04:15:45+00:00 Michael Ellerman michael@ellerman.id.au 2009-06-09T20:48:51+00:00 ba55bd74360ea4b8b95e73ed79474d37ff482b36 Add the option to build the code under arch/powerpc with -Werror. The intention is to make it harder for people to inadvertantly introduce warnings in the arch/powerpc code. It needs to be configurable so that if a warning is introduced, people can easily work around it while it's being fixed. The option is a negative, ie. don't enable -Werror, so that it will be turned on for allyes and allmodconfig builds. The default is n, in the hope that developers will build with -Werror, that will probably lead to some build breaks, I am prepared to be flamed. It's not enabled for math-emu, which is a steaming pile of warnings. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> 
Add the option to build the code under arch/powerpc with -Werror.

The intention is to make it harder for people to inadvertantly introduce
warnings in the arch/powerpc code. It needs to be configurable so that
if a warning is introduced, people can easily work around it while it's
being fixed.

The option is a negative, ie. don't enable -Werror, so that it will be
turned on for allyes and allmodconfig builds.

The default is n, in the hope that developers will build with -Werror,
that will probably lead to some build breaks, I am prepared to be flamed.

It's not enabled for math-emu, which is a steaming pile of warnings.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>