linux.git/arch/powerpc/kernel/Makefile, branch v3.14

clk: mpc5xxx: switch to COMMON_CLK, retire PPC_CLOCK

2014-01-12T17:53:04+00:00

the setup before the change was
- arch/powerpc/Kconfig had the PPC_CLOCK option, off by default
- depending on the PPC_CLOCK option the arch/powerpc/kernel/clock.c file
  was built, which implements the clk.h API but always returns -ENOSYS
  unless a platform registers specific callbacks
- the MPC52xx platform selected PPC_CLOCK but did not register any
  callbacks, thus all clk.h API calls keep resulting in -ENOSYS errors
  (which is OK, all peripheral drivers deal with the situation)
- the MPC512x platform selected PPC_CLOCK and registered specific
  callbacks implemented in arch/powerpc/platforms/512x/clock.c, thus
  provided real support for the clock API
- no other powerpc platform did select PPC_CLOCK

the situation after the change is
- the MPC512x platform implements the COMMON_CLK interface, and thus the
  PPC_CLOCK approach in arch/powerpc/platforms/512x/clock.c has become
  obsolete
- the MPC52xx platform still lacks genuine support for the clk.h API
  while this is not a change against the previous situation (the error
  code returned from COMMON_CLK stubs differs but every call still
  results in an error)
- with all references gone, the arch/powerpc/kernel/clock.c wrapper and
  the PPC_CLOCK option have become obsolete, as did the clk_interface.h
  header file

the switch from PPC_CLOCK to COMMON_CLK is done for all platforms within
the same commit such that multiplatform kernels (the combination of 512x
and 52xx within one executable) keep working

Cc: Mike Turquette 
Cc: Anatolij Gustschin 
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Gerhard Sittig 
Signed-off-by: Anatolij Gustschin

powerpc/book3s: Decode and save machine check event.

2013-12-05T05:05:20+00:00

Now that we handle machine check in linux, the MCE decoding should also
take place in linux host. This info is crucial to log before we go down
in case we can not handle the machine check errors. This patch decodes
and populates a machine check event which contain high level meaning full
MCE information.

We do this in real mode C code with ME bit on. The MCE information is still
available on emergency stack (in pt_regs structure format). Even if we take
another exception at this point the MCE early handler will allocate a new
stack frame on top of current one. So when we return back here we still have
our MCE information safe on current stack.

We use per cpu buffer to save high level MCE information. Each per cpu buffer
is an array of machine check event structure indexed by per cpu counter
mce_nest_count. The mce_nest_count is incremented every time we enter
machine check early handler in real mode to get the current free slot
(index = mce_nest_count - 1). The mce_nest_count is decremented once the
MCE info is consumed by virtual mode machine exception handler.

This patch provides save_mce_event(), get_mce_event() and release_mce_event()
generic routines that can be used by machine check handlers to populate and
retrieve the event. The routine release_mce_event() will free the event slot so
that it can be reused. Caller can invoke get_mce_event() with a release flag
either to release the event slot immediately OR keep it so that it can be
fetched again. The event slot can be also released anytime by invoking
release_mce_event().

This patch also updates kvm code to invoke get_mce_event to retrieve generic
mce event rather than paca->opal_mce_evt.

The KVM code always calls get_mce_event() with release flags set to false so
that event is available for linus host machine

If machine check occurs while we are in guest, KVM tries to handle the error.
If KVM is able to handle MC error successfully, it enters the guest and
delivers the machine check to guest. If KVM is not able to handle MC error, it
exists the guest and passes the control to linux host machine check handler
which then logs MC event and decides how to handle it in linux host. In failure
case, KVM needs to make sure that the MC event is available for linux host to
consume. Hence KVM always calls get_mce_event() with release flags set to false
and later it invokes release_mce_event() only if it succeeds to handle error.

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt

powerpc/book3s: Flush SLB/TLBs if we get SLB/TLB machine check errors on power7.

2013-12-05T05:04:39+00:00

If we get a machine check exception due to SLB or TLB errors, then flush
SLBs/TLBs and reload SLBs to recover. We do this in real mode before turning
on MMU. Otherwise we would run into nested machine checks.

If we get a machine check when we are in guest, then just flush the
SLBs and continue. This patch handles errors for power7. The next
patch will handle errors for power8

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Paul Mackerras 
Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Move lparcfg.c to platforms/pseries

2013-08-28T01:20:54+00:00

This file is entirely pseries specific nowadays, so move it out
of arch/powerpc/kernel where it doesn't belong anymore.

Signed-off-by: Benjamin Herrenschmidt

powerpc/8xx: Remove last traces of 8XX_MINIMAL_FPEMU

2013-08-14T04:58:53+00:00

The Kconfig symbol 8XX_MINIMAL_FPEMU was removed in commit 968219fa33
("powerpc/8xx: Remove 8xx specific "minimal FPU emulation""). But that
commit didn't remove all code depending on that symbol. Do so now.

Signed-off-by: Paul Bolle 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Better split CONFIG_PPC_INDIRECT_PIO and CONFIG_PPC_INDIRECT_MMIO

2013-08-14T04:57:50+00:00

Remove the generic PPC_INDIRECT_IO and ensure we only add overhead
to the right accessors. IE. If only CONFIG_PPC_INDIRECT_PIO is set,
we don't add overhead to all MMIO accessors.

Signed-off-by: Benjamin Herrenschmidt

powerpc/eeh: Move common part to kernel directory

2013-06-20T07:05:35+00:00

The patch moves the common part of EEH core into arch/powerpc/kernel
directory so that we needn't PPC_PSERIES while compiling POWERNV
platform:

        * Move the EEH common part into arch/powerpc/kernel
        * Move the functions for PCI hotplug from pSeries platform to
          arch/powerpc/kernel/pci-hotplug.c
        * Move CONFIG_EEH from arch/powerpc/platforms/pseries/Kconfig to
          arch/powerpc/platforms/Kconfig
        * Adjust makefile accordingly

Signed-off-by: Gavin Shan 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Add helper functions for transactional memory context switching

2013-02-15T05:58:52+00:00

Here we add the helper functions to be used when context switching.  These
allow us to fully reclaim and recheckpoint a transaction.

We introduce a new paca field called tm_scratch to help us store away register
values when doing the low level tm reclaim register save.

Signed-off-by: Matt Evans 
Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Build kernel with -mcmodel=medium

2013-01-10T06:00:31+00:00

Finally remove the two level TOC and build with -mcmodel=medium.

Unfortunately we can't build modules with -mcmodel=medium due to
the tricks the kernel module loader plays with percpu data:

# -mcmodel=medium breaks modules because it uses 32bit offsets from
# the TOC pointer to create pointers where possible. Pointers into the
# percpu data area are created by this method.
#
# The kernel module loader relocates the percpu data section from the
# original location (starting with 0xd...) to somewhere in the base
# kernel percpu data space (starting with 0xc...). We need a full
# 64bit relocation for this to work, hence -mcmodel=large.

On older kernels we fall back to the two level TOC (-mminimal-toc)

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Relocate prom_init.c on 64bit

2013-01-10T06:00:25+00:00

The ppc64 kernel can get loaded at any address which means
our very early init code in prom_init.c must be relocatable. We do
this with a pretty nasty RELOC() macro that we wrap accesses of
variables with. It is very fragile and sometimes we forget to add a
RELOC() to an uncommon path or sometimes a compiler change breaks it.

32bit has a much more elegant solution where we build prom_init.c
with -mrelocatable and then process the relocations manually.
Unfortunately we can't do the equivalent on 64bit and we would
have to build the entire kernel relocatable (-pie), resulting in a
large increase in kernel footprint (megabytes of relocation data).
The relocation data will be marked __initdata but it still creates
more pressure on our already tight memory layout at boot.

Alan Modra pointed out that the 64bit ABI is relocatable even
if we don't build with -pie, we just need to relocate the TOC.
This patch implements that idea and relocates the TOC entries of
prom_init.c. An added bonus is there are very few relocations to
process which helps keep boot times on simulators down.

gcc does not put 64bit integer constants into the TOC but to be
safe we may want a build time script which passes through the
prom_init.c TOC entries to make sure everything looks reasonable.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt