[PATCH 6/6] powerpc: Implement PPR save/restore

When the task enters in to kernel space, the user defined priority (PPR)
will be saved in to PACA at the beginning of first level exception
vector and then copy from PACA to thread_info in second level vector.
PPR will be restored from thread_info before exits the kernel space.

P7/P8 temporarily raises the thread priority to higher level during
exception until the program executes HMT_* calls. But it will not modify
PPR register. So we save PPR value whenever some register is available
to use and then calls HMT_MEDIUM to increase the priority. This feature
supports on P7 or later processors.

We save/ restore PPR for all exception vectors except system call entry.
GLIBC will be saving / restore for system calls. So the default PPR
value (3) will be set for the system call exit when the task returned
to the user space.
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[PATCH 5/6] powerpc: Macros for saving/restore PPR

Several macros are defined for saving and restore user defined PPR value.
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[PATCH 4/6] powerpc: Define ppr in thread_struct

ppr in thread_struct is used to save PPR and restore it before process exits
from kernel.

This patch sets the default priority to 3 when tasks are created such
that users can use 4 for higher priority tasks.
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[PATCH 3/6] powerpc: Increase exceptions arrays in paca struct to save PPR

Using paca to save user defined PPR value in the first level exception vector.
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[PATCH 2/6] powerpc: Enable PPR save/restore

SMT thread status register (PPR) is used to set thread priority. This patch
enables PPR save/restore feature (CPU_FTR_HAS_PPR) on POWER7 and POWER8 systems.
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[PATCH 1/6] powerpc: Move branch instruction from ACCOUNT_CPU_USER_ENTRY to caller

The first instruction in ACCOUNT_CPU_USER_ENTRY is 'beq' which checks for
exceptions coming from kernel mode. PPR value will be saved immediately after
ACCOUNT_CPU_USER_ENTRY and is also for user level exceptions. So moved this
branch instruction in the caller code.
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Support for stalled-cycles-frontend and stalled-cycles-backend is
added for e500-based processors.

The following mappings are used:

stalled-cycles-frontend or idle-cycles-frontend:
Com:18 Cycles decode stalled

stalled-cycles-backend or idle-cycles-backend
Com:19 cycles issue stalled
Signed-off-by: Chris Freehill <chrisf@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

By using the compiler intrinsics instead of hand-crafted opaque inline
assembler for byte-swapping, we let the compiler see what's actually
happening and it gets to use lwbrx/stwbrx instructions instead of a
normal load/store coupled with a sequence of rlwimi instructions to
move bits around.

Compiled-tested only. It gave a code size reduction of almost 4% for
ext2, and more like 2.5% for ext3/ext4.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Use for_each_compatible_node() macro instead of open coding it.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Use for_each_compatible_node() macro instead of open coding it.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Use for_each_compatible_node() macro instead of open coding it.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

For PR KVM we allow userspace to map 0xc000000000000000. Because
transitioning from userspace to the guest kernel may use the relocated
exception vectors we have to disable relocation on exceptions whenever
PR KVM is active as we cannot trust that address.

This issue does not apply to HV KVM, since changing from a guest to the
hypervisor will never use the relocated exception vectors.

Currently the hypervisor interface only allows us to toggle relocation
on exceptions on a partition wide scope, so we need to globally disable
relocation on exceptions when the first PR KVM instance is started and
only re-enable them when all PR KVM instances have been destroyed.

It's a bit heavy handed, but until the hypervisor gives us a lightweight
way to toggle relocation on exceptions on a single thread it's only real
option.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Motivation:
IBM Blue Gene/Q comes with some very strange firmware that I'm trying to get out
of using in the kernel.  So instead I spin all the threads in the boot wrapper
(using the firmware) and have them enter the kexec stub, pre-translated at the
virtual "linear" address, never touching firmware again.

This works strategy works wonderfully, but I need the following patch in the
kexec stub. I believe it should not effect Book3S and Book3E does not appear
to be here yet so I'd love to get any criticisms up front.

This patch adds two items:

1) Book3e requires that GPR4 survive the "hold" process, so we make
   sure that happens.
2) Book3e has no real mode, and the hold code exploits this.  Since
   these processors ares always translated, we arrange for the kexeced
   threads to enter the hold code using the normal kernel linear mapping.
Signed-off-by: Jimi Xenidis <jimix@pobox.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Use for_each_node_by_type() macro instead of open coding it.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This patch fixes MAX_STACK_TRACE_ENTRIES too low warning for ppc32,
which is similar to commit 12660b17.
Reported-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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 <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Now we relocate prom_init.c on 64bit we can finally remove the
nasty RELOC() macro.

Finally a patch that I can claim has a net positive effect on
the kernel. It doesn't happen very often.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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 <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Enable PRINTK_TIME in pasemi_defconfig. Also regenerate it, it seems
that a lot of options have moved around since last time savedefconfig
was ran on it.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The third argument for of_get_property() is a pointer, hence pass
NULL instead of 0.
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Change the representation of the PMU flags from decimal to hex since they
are bitfields which are easier to read in hex.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This patch actually hooks up doorbell interrupts on POWER8:

- Select the PPC_DOORBELL Kconfig option from PPC_PSERIES

- Add the doorbell CPU feature bit to POWER8

- We define a new pSeries_cause_ipi_mux() function that issues a
  doorbell interrupt if the recipient is another thread within the same
  core as the sender. If the recipient is in a different core it falls
  back to using XICS to deliver the IPI as before.

- During pSeries_smp_probe() at boot, we check if doorbell interrupts
  are supported. If they are we set the cause_ipi function pointer to
  the above mentioned function, otherwise we leave it as whichever XICS
  cause_ipi function was determined by xics_smp_probe().
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Tested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Move the rule to build doorbell support out of the Makefile and into a
new Kconfig boolean that platforms can select.

We will add doorbell support to pseries as well in the next patch.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Tested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This patch adds the logic to properly handle doorbells that come in when
interrupts have been soft disabled and to replay them when interrupts
are re-enabled:

- masked_##_H##interrupt is modified to leave interrupts enabled when a
  doorbell has come in since doorbells are edge sensitive and as such
  won't be automatically re-raised.

- __check_irq_replay now tests if a doorbell happened on book3s, and
  returns either 0xe80 or 0xa00 depending on whether we are the
  hypervisor or not.

- restore_check_irq_replay now tests for the two possible server
  doorbell vector numbers to replay.

- __replay_interrupt also adds tests for the two server doorbell vector
  numbers, and is modified to use a compare instruction rather than an
  andi. on the single bit difference between 0x500 and 0x900.

The last two use a CPU feature section to avoid needlessly testing
against the hypervisor vector if it is not the hypervisor, and vice
versa.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

On book3s we have two msgsnd instructions with differing privilege
levels. This patch selects the appropriate instruction to use whenever
we send a doorbell interrupt.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Tested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Directed Privileged Doorbell Interrupts come in at 0xa00 (or
0xc000000000004a00 if relocation on exception is enabled), so add
exception vectors at these locations.

If doorbell support is not compiled in we handle it as an
unknown_exception.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Tested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Directed Hypervisor Doorbell Interrupts come in at 0xe80 (or
0xc000000000004e80 if relocation on exceptions is enabled), so add
exception vectors at these locations.

If doorbell support is not compiled in we handle it as an
unknown_exception.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Tested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

There are a few key differences between doorbells on server compared
with embedded that we care about on Linux, namely:

- We have a new msgsndp instruction for directed privileged doorbells.
  msgsnd is used for directed hypervisor doorbells.
- The tag we use in the instruction is the Thread Identification
  Register of the recipient thread (since server doorbells can only
  occur between threads within a single core), and is only 7 bits wide.
- A new message type is introduced for server doorbells (none of the
  existing book3e message types are currently supported on book3s).
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Tested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This adds the marvel phy which is present on the ml507 board.
Without this ethtool causes kernel-oopses.

Tested on ml507 board.
Signed-off-by: Gernot Vormayr <gvormayr@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This patch consists of:
- Add driver for OCM component
- Export OCM Information at /sys/kernel/debug/ppc4xx_ocm/info
Signed-off-by: Vinh Nguyen Huu Tuong <vhtnguyen@apm.com>
Acked-by: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we search for the best_energy hcall using a custom function.  Move
this to using the firmware_feature_table.
Signed-off-by: Michael Neuling <mikey@neuling.org>
cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
cc: Linux PPC dev <linuxppc-dev@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This allows firmware_features_table names to add a '*' at the end so that only
partial strings are matched.

When a '*' is added, only upto the '*' is matched when setting firmware feature
bits.

This is useful for the matching best energy feature.
Signed-off-by: Michael Neuling <mikey@neuling.org>
cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
cc: Linux PPC dev <linuxppc-dev@ozlabs.org>
Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The watchdog and FIT code has been #if 0'd for ever, if the CPU takes
an exception to either of those vectors it will jump into the middle
of the PIT or Data TLB code and surely crash.

At least some (all?) 405 cores have both the WDT and FIT
vectors defined, so lets have proper entry points for them.

Tested that the WDT vector works on a 405F6 core.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The pseries CPU hotplug code uses cede_processor without properly
synchronizing the SW and HW interrupt enable state. This fixes
it using the same helpers that were written for the idle code.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>

=======================
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

This patch adds a crypto driver which provides a powerpc accelerated
implementation of SHA-1, accelerated in that it is written in asm.

Original patch by Paul, minor fixups for upstream by moi.

Lightly tested on 64-bit with the test program here:

 http://michael.ellerman.id.au/files/junkcode/sha1test.c

Seems to work, and is "not slower" than the generic version.

Needs testing on 32-bit.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Pull ARM fixes from Russell King.

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7616/1: cache-l2x0: aurora: Use writel_relaxed instead of writel
  ARM: 7615/1: cache-l2x0: aurora: Invalidate during clean operation with WT enable
  ARM: 7614/1: mm: fix wrong branch from Cortex-A9 to PJ4b
  ARM: 7612/1: imx: Do not select some errata that depends on !ARCH_MULTIPLATFORM
  ARM: 7611/1: VIC: fix bug in VIC irqdomain code
  ARM: 7610/1: versatile: bump IRQ numbers
  ARM: 7609/1: disable errata work-arounds which access secure registers
  ARM: 7608/1: l2x0: Only set .set_debug on PL310 r3p0 and earlier

Pull EDAC fixes from Borislav Petkov:
 "Two error path fixes causing a crash and a Kconfig fix for an issue
  which spilled all EDAC suboptions into the 'Device Drivers' menu."

* tag 'edac_fixes_for_3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  EDAC: Cleanup device deregistering path
  EDAC: Fix EDAC Kconfig menu
  EDAC: Fix kernel panic on module unloading

The check for a pmd being in the process of being split was dropped by
mistake by commit d10e63f2 ("mm: numa: Create basic numa page
hinting infrastructure"). Put it back.
Reported-by: Dave Jones <davej@redhat.com>
Debugged-by: Hillf Danton <dhillf@gmail.com>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Kirill Shutemov <kirill@shutemov.name>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 3a50597d ("KEYS: Make the session and process keyrings
per-thread") removed the definition of the thread_group_cred structure,
but left a now unused pointer in struct cred.
Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ARM SoC fixes from Olof Johansson:
 "People are back from the holiday breaks, and it shows.  Here are a
  bunch of fixes for a number of platforms:
   - A couple of small fixes for Nomadik
   - A larger set of changes for kirkwood/mvebu
     - uart driver selection, dt clocks, gpio-poweroff fixups, a few
       __init annotation fixes and some error handling improvement in
       their xor dma driver.
   - i.MX had a couple of minor fixes (and a critical one for flexcan2
     clock setup)
   - MXS has a small board fix and a framebuffer bugfix
   - A set of fixes for Samsung Exynos, fixing default bootargs and some
     Exynos5440 clock issues
   - A set of OMAP changes including PM fixes and a few sparse warning
     fixups

  All in all a bit more positive code delta than we'd ideally want to
  see here, mostly from the OMAP PM changes, but nothing overly crazy."

* tag 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (44 commits)
  ARM: clps711x: Fix bad merge of clockevents setup
  ARM: highbank: save and restore L2 cache and GIC on suspend
  ARM: highbank: add a power request clear
  ARM: highbank: fix secondary boot and hotplug
  ARM: highbank: fix typos with hignbank in power request functions
  ARM: dts: fix highbank cpu mpidr values
  ARM: dts: add device_type prop to cpu nodes on Calxeda platforms
  ARM: mx5: Fix MX53 flexcan2 clock
  ARM: OMAP2+: am33xx-hwmod: Fix wrongly terminated am33xx_usbss_mpu_irqs array
  pinctrl: mvebu: make pdma clock on dove mandatory
  ARM: Dove: Add pinctrl clock to DT
  dma: mv_xor: fix error handling for clocks
  dma: mv_xor: fix error handling of mv_xor_channel_add()
  arm: mvebu: Add missing ; for cpu node.
  arm: mvebu: Armada XP MV78230 has only three Ethernet interfaces
  arm: mvebu: Armada XP MV78230 has two cores, not one
  clk: mvebu: Remove inappropriate __init tagging
  ARM: Kirkwood: Use fixed-regulator instead of board gpio call
  ARM: Kirkwood: Fix missing sdio clock
  ARM: Kirkwood: Switch TWSI1 of 88f6282 to DT clock providers
  ...