Commit Graph

119 Commits

Author SHA1 Message Date
Andrew Donnellan bd59380c5b powerpc/rtas: Restrict RTAS requests from userspace
A number of userspace utilities depend on making calls to RTAS to retrieve
information and update various things.

The existing API through which we expose RTAS to userspace exposes more
RTAS functionality than we actually need, through the sys_rtas syscall,
which allows root (or anyone with CAP_SYS_ADMIN) to make any RTAS call they
want with arbitrary arguments.

Many RTAS calls take the address of a buffer as an argument, and it's up to
the caller to specify the physical address of the buffer as an argument. We
allocate a buffer (the "RMO buffer") in the Real Memory Area that RTAS can
access, and then expose the physical address and size of this buffer in
/proc/powerpc/rtas/rmo_buffer. Userspace is expected to read this address,
poke at the buffer using /dev/mem, and pass an address in the RMO buffer to
the RTAS call.

However, there's nothing stopping the caller from specifying whatever
address they want in the RTAS call, and it's easy to construct a series of
RTAS calls that can overwrite arbitrary bytes (even without /dev/mem
access).

Additionally, there are some RTAS calls that do potentially dangerous
things and for which there are no legitimate userspace use cases.

In the past, this would not have been a particularly big deal as it was
assumed that root could modify all system state freely, but with Secure
Boot and lockdown we need to care about this.

We can't fundamentally change the ABI at this point, however we can address
this by implementing a filter that checks RTAS calls against a list
of permitted calls and forces the caller to use addresses within the RMO
buffer.

The list is based off the list of calls that are used by the librtas
userspace library, and has been tested with a number of existing userspace
RTAS utilities. For compatibility with any applications we are not aware of
that require other calls, the filter can be turned off at build time.

Cc: stable@vger.kernel.org
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200820044512.7543-1-ajd@linux.ibm.com
2020-10-06 23:22:27 +11:00
Nathan Lynch ec2fc2a9e9 powerpc/rtas: don't online CPUs for partition suspend
Partition suspension, used for hibernation and migration, requires
that the OS place all but one of the LPAR's processor threads into one
of two states prior to calling the ibm,suspend-me RTAS function:

  * the architected offline state (via RTAS stop-self); or
  * the H_JOIN hcall, which does not return until the partition
    resumes execution

Using H_CEDE as the offline mode, introduced by
commit 3aa565f53c ("powerpc/pseries: Add hooks to put the CPU into
an appropriate offline state"), means that any threads which are
offline from Linux's point of view must be moved to one of those two
states before a partition suspension can proceed.

This was eventually addressed in commit 120496ac2d ("powerpc: Bring
all threads online prior to migration/hibernation"), which added code
to temporarily bring up any offline processor threads so they can call
H_JOIN. Conceptually this is fine, but the implementation has had
multiple races with cpu hotplug operations initiated from user
space[1][2][3], the error handling is fragile, and it generates
user-visible cpu hotplug events which is a lot of noise for a platform
feature that's supposed to minimize disruption to workloads.

With commit 3aa565f53c ("powerpc/pseries: Add hooks to put the CPU
into an appropriate offline state") reverted, this code becomes
unnecessary, so remove it. Since any offline CPUs now are truly
offline from the platform's point of view, it is no longer necessary
to bring up CPUs only to have them call H_JOIN and then go offline
again upon resuming. Only active threads are required to call H_JOIN;
stopped threads can be left alone.

[1] commit a6717c01dd ("powerpc/rtas: use device model APIs and
    serialization during LPM")
[2] commit 9fb603050f ("powerpc/rtas: retry when cpu offline races
    with suspend/migration")
[3] commit dfd718a2ed ("powerpc/rtas: Fix a potential race between
    CPU-Offline & Migration")

Fixes: 120496ac2d ("powerpc: Bring all threads online prior to migration/hibernation")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200612051238.1007764-3-nathanl@linux.ibm.com
2020-07-16 13:12:35 +10:00
Leonardo Bras b664db8e3f powerpc/rtas: Implement reentrant rtas call
Implement rtas_call_reentrant() for reentrant rtas-calls:
"ibm,int-on", "ibm,int-off",ibm,get-xive" and  "ibm,set-xive".

On LoPAPR Version 1.1 (March 24, 2016), from 7.3.10.1 to 7.3.10.4,
items 2 and 3 say:

2 - For the PowerPC External Interrupt option: The * call must be
reentrant to the number of processors on the platform.
3 - For the PowerPC External Interrupt option: The * argument call
buffer for each simultaneous call must be physically unique.

So, these rtas-calls can be called in a lockless way, if using
a different buffer for each cpu doing such rtas call.

For this, it was suggested to add the buffer (struct rtas_args)
in the PACA struct, so each cpu can have it's own buffer.
The PACA struct received a pointer to rtas buffer, which is
allocated in the memory range available to rtas 32-bit.

Reentrant rtas calls are useful to avoid deadlocks in crashing,
where rtas-calls are needed, but some other thread crashed holding
the rtas.lock.

This is a backtrace of a deadlock from a kdump testing environment:

  #0 arch_spin_lock
  #1  lock_rtas ()
  #2  rtas_call (token=8204, nargs=1, nret=1, outputs=0x0)
  #3  ics_rtas_mask_real_irq (hw_irq=4100)
  #4  machine_kexec_mask_interrupts
  #5  default_machine_crash_shutdown
  #6  machine_crash_shutdown
  #7  __crash_kexec
  #8  crash_kexec
  #9  oops_end

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
[mpe: Move under #ifdef PSERIES to avoid build breakage]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200518234245.200672-3-leobras.c@gmail.com
2020-06-02 20:59:08 +10:00
Nathan Lynch 10e4850d7c powerpc/rtas: allow rescheduling while changing cpu states
rtas_cpu_state_change_mask() potentially operates on scores of cpus,
so explicitly allow rescheduling in the loop body.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802192926.19277-3-nathanl@linux.ibm.com
2019-08-20 21:22:27 +10:00
Nathan Lynch a6717c01dd powerpc/rtas: use device model APIs and serialization during LPM
The LPAR migration implementation and userspace-initiated cpu hotplug
can interleave their executions like so:

1. Set cpu 7 offline via sysfs.

2. Begin a partition migration, whose implementation requires the OS
   to ensure all present cpus are online; cpu 7 is onlined:

     rtas_ibm_suspend_me -> rtas_online_cpus_mask -> cpu_up

   This sets cpu 7 online in all respects except for the cpu's
   corresponding struct device; dev->offline remains true.

3. Set cpu 7 online via sysfs. _cpu_up() determines that cpu 7 is
   already online and returns success. The driver core (device_online)
   sets dev->offline = false.

4. The migration completes and restores cpu 7 to offline state:

     rtas_ibm_suspend_me -> rtas_offline_cpus_mask -> cpu_down

This leaves cpu7 in a state where the driver core considers the cpu
device online, but in all other respects it is offline and
unused. Attempts to online the cpu via sysfs appear to succeed but the
driver core actually does not pass the request to the lower-level
cpuhp support code. This makes the cpu unusable until the cpu device
is manually set offline and then online again via sysfs.

Instead of directly calling cpu_up/cpu_down, the migration code should
use the higher-level device core APIs to maintain consistent state and
serialize operations.

Fixes: 120496ac2d ("powerpc: Bring all threads online prior to migration/hibernation")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802192926.19277-2-nathanl@linux.ibm.com
2019-08-20 21:22:27 +10:00
Nathan Lynch ae2e953fdc powerpc/rtas: Unexport rtas_online_cpus_mask, rtas_offline_cpus_mask
These aren't used by modular code, nor should they be.

Fixes: 120496ac2d ("powerpc: Bring all threads online prior to migration/hibernation")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190718162214.5694-1-nathanl@linux.ibm.com
2019-08-05 18:53:03 +10:00
Linus Torvalds 192f0f8e9d powerpc updates for 5.3
Notable changes:
 
  - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver, as well
    as some other functions only used by drivers that haven't (yet?) made it
    upstream.
 
  - A fix for a bug in our handling of hardware watchpoints (eg. perf record -e
    mem: ...) which could lead to register corruption and kernel crashes.
 
  - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for vmalloc
    when using the Radix MMU.
 
  - A large but incremental rewrite of our exception handling code to use gas
    macros rather than multiple levels of nested CPP macros.
 
 And the usual small fixes, cleanups and improvements.
 
 Thanks to:
   Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju
   T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Cédric Le Goater,
   Christian Lamparter, Christophe Leroy, Christophe Lombard, Christoph Hellwig,
   Daniel Axtens, Denis Efremov, Enrico Weigelt, Frederic Barrat, Gautham R.
   Shenoy, Geert Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg
   Kurz, Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro
   Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N. Rao,
   Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi Bangoria,
   Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher Boessenkool, Shaokun
   Zhang, Shawn Anastasio, Stewart Smith, Suraj Jitindar Singh, Thiago Jung
   Bauermann, YueHaibing.
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Merge tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver,
     as well as some other functions only used by drivers that haven't
     (yet?) made it upstream.

   - A fix for a bug in our handling of hardware watchpoints (eg. perf
     record -e mem: ...) which could lead to register corruption and
     kernel crashes.

   - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for
     vmalloc when using the Radix MMU.

   - A large but incremental rewrite of our exception handling code to
     use gas macros rather than multiple levels of nested CPP macros.

  And the usual small fixes, cleanups and improvements.

  Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab,
  Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann,
  Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe
  Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis
  Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert
  Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz,
  Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro
  Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N.
  Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi
  Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher
  Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj
  Jitindar Singh, Thiago Jung Bauermann, YueHaibing"

* tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits)
  powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state.
  powerpc/eeh: Handle hugepages in ioremap space
  ocxl: Update for AFU descriptor template version 1.1
  powerpc/boot: pass CONFIG options in a simpler and more robust way
  powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h
  powerpc/irq: Don't WARN continuously in arch_local_irq_restore()
  powerpc/module64: Use symbolic instructions names.
  powerpc/module32: Use symbolic instructions names.
  powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h
  powerpc/module64: Fix comment in R_PPC64_ENTRY handling
  powerpc/boot: Add lzo support for uImage
  powerpc/boot: Add lzma support for uImage
  powerpc/boot: don't force gzipped uImage
  powerpc/8xx: Add microcode patch to move SMC parameter RAM.
  powerpc/8xx: Use IO accessors in microcode programming.
  powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c
  powerpc/8xx: refactor programming of microcode CPM params.
  powerpc/8xx: refactor printing of microcode patch name.
  powerpc/8xx: Refactor microcode write
  powerpc/8xx: refactor writing of CPM microcode arrays
  ...
2019-07-13 16:08:36 -07:00
Linus Torvalds e0e86b111b Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP/hotplug updates from Thomas Gleixner:
 "A small set of updates for SMP and CPU hotplug:

   - Abort disabling secondary CPUs in the freezer when a wakeup is
     pending instead of evaluating it only after all CPUs have been
     offlined.

   - Remove the shared annotation for the strict per CPU cfd_data in the
     smp function call core code.

   - Remove the return values of smp_call_function() and on_each_cpu()
     as they are unconditionally 0. Fixup the few callers which actually
     bothered to check the return value"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Remove smp_call_function() and on_each_cpu() return values
  smp: Do not mark call_function_data as shared
  cpu/hotplug: Abort disabling secondary CPUs if wakeup is pending
  cpu/hotplug: Fix notify_cpu_starting() reference in bringup_wait_for_ap()
2019-07-08 10:39:56 -07:00
Nathan Lynch 9fb603050f powerpc/rtas: retry when cpu offline races with suspend/migration
The protocol for suspending or migrating an LPAR requires all present
processor threads to enter H_JOIN. So if we have threads offline, we
have to temporarily bring them up. This can race with administrator
actions such as SMT state changes. As of dfd718a2ed ("powerpc/rtas:
Fix a potential race between CPU-Offline & Migration"),
rtas_ibm_suspend_me() accounts for this, but errors out with -EBUSY
for what almost certainly is a transient condition in any reasonable
scenario.

Callers of rtas_ibm_suspend_me() already retry when -EAGAIN is
returned, and it is typical during a migration for that to happen
repeatedly for several minutes polling the H_VASI_STATE hcall result
before proceeding to the next stage.

So return -EAGAIN instead of -EBUSY when this race is
encountered. Additionally: logging this event is still appropriate but
use pr_info instead of pr_err; and remove use of unlikely() while here
as this is not a hot path at all.

Fixes: dfd718a2ed ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:54 +10:00
Nadav Amit caa759323c smp: Remove smp_call_function() and on_each_cpu() return values
The return value is fixed. Remove it and amend the callers.

[ tglx: Fixup arm/bL_switcher and powerpc/rtas ]

Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20190613064813.8102-2-namit@vmware.com
2019-06-23 14:26:26 +02:00
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
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 <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Mike Rapoport 0ba9e6edd4 memblock: drop memblock_alloc_base()
The memblock_alloc_base() function tries to allocate a memory up to the
limit specified by its max_addr parameter and panics if the allocation
fails.  Replace its usage with memblock_phys_alloc_range() and make the
callers check the return value and panic in case of error.

Link: http://lkml.kernel.org/r/1548057848-15136-10-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>		[powerpc]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com>				[c-sky]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Juergen Gross <jgross@suse.com>			[Xen]
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-12 10:04:01 -07:00
Gautham R. Shenoy dfd718a2ed powerpc/rtas: Fix a potential race between CPU-Offline & Migration
Live Partition Migrations require all the present CPUs to execute the
H_JOIN call, and hence rtas_ibm_suspend_me() onlines any offline CPUs
before initiating the migration for this purpose.

The commit 85a88cabad
("powerpc/pseries: Disable CPU hotplug across migrations")
disables any CPU-hotplug operations once all the offline CPUs are
brought online to prevent any further state change. Once the
CPU-Hotplug operation is disabled, the code assumes that all the CPUs
are online.

However, there is a minor window in rtas_ibm_suspend_me() between
onlining the offline CPUs and disabling CPU-Hotplug when a concurrent
CPU-offline operations initiated by the userspace can succeed thereby
nullifying the the aformentioned assumption. In this unlikely case
these offlined CPUs will not call H_JOIN, resulting in a system hang.

Fix this by verifying that all the present CPUs are actually online
after CPU-Hotplug has been disabled, failing which we restore the
state of the offline CPUs in rtas_ibm_suspend_me() and return an
-EBUSY.

Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-13 22:21:25 +11:00
Michael Bringmann 65b9fdadfc powerpc/pseries/mobility: Extend start/stop topology update scope
The powerpc mobility code may receive RTAS requests to perform PRRN
(Platform Resource Reassignment Notification) topology changes at any
time, including during LPAR migration operations.

In some configurations where the affinity of CPUs or memory is being
changed on that platform, the PRRN requests may apply or refer to
outdated information prior to the complete update of the device-tree.

This patch changes the duration for which topology updates are
suppressed during LPAR migrations from just the rtas_ibm_suspend_me()
/ 'ibm,suspend-me' call(s) to cover the entire migration_store()
operation to allow all changes to the device-tree to be applied prior
to accepting and applying any PRRN requests.

For tracking purposes, pr_info notices are added to the functions
start_topology_update() and stop_topology_update() of 'numa.c'.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-13 22:21:25 +11:00
Nathan Fontenot 85a88cabad powerpc/pseries: Disable CPU hotplug across migrations
When performing partition migrations all present CPUs must be online
as all present CPUs must make the H_JOIN call as part of the migration
process. Once all present CPUs make the H_JOIN call, one CPU is returned
to make the rtas call to perform the migration to the destination system.

During testing of migration and changing the SMT state we have found
instances where CPUs are offlined, as part of the SMT state change,
before they make the H_JOIN call. This results in a hung system where
every CPU is either in H_JOIN or offline.

To prevent this this patch disables CPU hotplug during the migration
process.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Paul Burton ac85174403 powerpc: Remove -Wattribute-alias pragmas
With SYSCALL_DEFINEx() disabling -Wattribute-alias generically, there's
no need to duplicate that for PowerPC syscalls.

This reverts commit 4155203739 ("powerpc: fix build failure by
disabling attribute-alias warning in pci_32") and commit 2479bfc9bc
("powerpc: Fix build by disabling attribute-alias warning for
SYSCALL_DEFINEx").

Signed-off-by: Paul Burton <paul.burton@mips.com>
Acked-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-25 23:21:13 +09:00
Christophe Leroy 2479bfc9bc powerpc: Fix build by disabling attribute-alias warning for SYSCALL_DEFINEx
GCC 8.1 emits warnings such as the following. As arch/powerpc code is
built with -Werror, this breaks the build with GCC 8.1.

  In file included from arch/powerpc/kernel/pci_64.c:23:
  ./include/linux/syscalls.h:233:18: error: 'sys_pciconfig_iobase' alias
  between functions of incompatible types 'long int(long int, long
  unsigned int, long unsigned int)' and 'long int(long int, long int,
  long int)' [-Werror=attribute-alias]
    asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
                    ^~~
  ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx'
    __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)

This patch inhibits those warnings.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Trim change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:24 +10:00
Al Viro 4c392e6591 powerpc/syscalls: switch rtas(2) to SYSCALL_DEFINE
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mpe: Update sys_ni.c for s/ppc_rtas/sys_rtas/]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:14 +10:00
Will Deacon 58788a9b60 locking/arch, powerpc/rtas: Use arch_spin_lock() instead of arch_spin_lock_flags()
arch_spin_lock_flags() is an internal part of the spinlock implementation
and is no longer available when SMP=n and DEBUG_SPINLOCK=y, so the PPC
RTAS code fails to compile in this configuration:

   arch/powerpc/kernel/rtas.c: In function 'lock_rtas':
>> arch/powerpc/kernel/rtas.c:81:2: error: implicit declaration of function 'arch_spin_lock_flags' [-Werror=implicit-function-declaration]
     arch_spin_lock_flags(&rtas.lock, flags);
     ^~~~~~~~~~~~~~~~~~~~

Since there's no good reason to use arch_spin_lock_flags() here (the code
in question already calls local_irq_save(flags)), switch it over to
arch_spin_lock and get things building again.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1508327469-20231-1-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-18 15:15:07 +02:00
Michal Hocko 0ee931c4e3 mm: treewide: remove GFP_TEMPORARY allocation flag
GFP_TEMPORARY was introduced by commit e12ba74d8f ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE.  It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation.  As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag.  How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.

The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory.  So
this is rather misleading and hard to evaluate for any benefits.

I have checked some random users and none of them has added the flag
with a specific justification.  I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring.  This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.

I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse.  Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL.  Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.

I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.

This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic.  It
seems to be a heuristic without any measured advantage for most (if not
all) its current users.  The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers.  So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.

[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org

[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
  Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-13 18:53:16 -07:00
Gavin Shan 8b25778321 powerpc/kernel: Fix unbalanced refcount on RTAS device node
The RTAS device-tree node's refcount has been increased by one in
the function call of_find_node_by_name(), but it's missed to be
decreased by one in the error path. It leads to unbalanced refcount
on RTAS device-tree node.

This fixes above issue by decreasing RTAS device-tree node's refcount
in error path.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-01-25 13:34:21 +11:00
Gavin Shan de6d2d1b7b powerpc/kernel: Use of_property_read_u32() in rtas_initialize()
This uses of_property_read_u32() in rtas_initialize() so that we
needn't explicitly care the CPU's endian.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-01-25 13:34:20 +11:00
Gavin Shan dbecd50930 powerpc/kernel: Remove nested if statements in rtas_initialize()
This removes the unnecessary nested if statements in function
rtas_initialize(), to simplify the code. No functional changes
introduced.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-01-25 13:34:20 +11:00
Linus Torvalds 7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24 11:46:01 -08:00
Daniel Axtens 95ec77c06e powerpc: Make ppc_md.{halt, restart} __noreturn
powernv marks it's halt and restart calls as __noreturn. However,
ppc_md does not have this annotation. Add the annotation to ppc_md,
and then to every halt/restart function that is missing it.

Additionally, I have verified that all of these functions do not
return. Occasionally I have added a spin loop to be sure.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-14 21:12:06 +10:00
Benjamin Herrenschmidt 484cc1ed3c powerpc/rtas: Don't test for machine type in rtas_initialize()
The test is unnecessary, the FW_FEATURE_LPAR is sufficient as there
exist no other LPAR type that has RTAS.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-13 18:15:38 +10:00
Andrew Donnellan a9862c7440 powerpc/rtas: Fix array overrun in ppc_rtas() syscall
If ppc_rtas() is called with args.nargs == 16 and args.nret == 0,
args.rets is set to point to &args.args[16], which is beyond the end of
the args.args array. This results in a minor read overrun of the array
when we check the first return code (which, per PAPR, is a required
output of all RTAS calls) to see if there's been a hardware error.

Change the nargs/nret check to ensure nargs is <= 15, allowing room for
the status code. Users shouldn't be calling with nret == 0, but there's
no real harm if they do, so we don't stop them.

Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 23:49:52 +10:00
Michael Ellerman cd5cdeb6c8 powerpc/rtas: Make enter_rtas() private
There are no longer any users of enter_rtas() outside of rtas.c, so make
it "private", by moving the declaration inside rtas.c. Hopefully this
will encourage people to use one of the wrappers which takes the sharp
edges off the RTAS calling sequence.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-17 22:40:56 +11:00
Michael Ellerman 4456f45246 powerpc/rtas: Use rtas_call_unlocked() in call_rtas_display_status()
Although call_rtas_display_status() does actually want to use the
regular RTAS locking, it doesn't want the extra logic that is in
rtas_call(), so currently it open codes the logic.

Instead we can use rtas_call_unlocked(), after taking the RTAS lock.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-17 22:40:56 +11:00
Michael Ellerman 209eb4e5cb powerpc/rtas: Add rtas_call_unlocked()
Most users of RTAS (Run-Time Abstraction Services) use rtas_call(),
which deals with locking as well as endian handling.

However we have two users outside of rtas.c that can't use rtas_call()
because they have different locking requirements.

The hotplug CPU code can't take the RTAS lock because the CPU would go
offline with the lock held and no other CPUs would be able to call RTAS
until the CPU came back online.

The xmon code doesn't want to take the lock because it would risk dead
locking when we are trying to recover from a crash.

Both sites required multiple patches when we added little endian
support, proving that programmers can't do endian right.

Although that ship has sailed, we can still clean the code up by
providing an unlocked version of rtas_call() which avoids the need to
open code the logic elsewhere.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-17 22:40:55 +11:00
Vasant Hegde 8832317f66 powerpc/rtas: Validate rtas.entry before calling enter_rtas()
Currently we do not validate rtas.entry before calling enter_rtas(). This
leads to a kernel oops when user space calls rtas system call on a powernv
platform (see below). This patch adds code to validate rtas.entry before
making enter_rtas() call.

  Oops: Exception in kernel mode, sig: 4 [#1]
  SMP NR_CPUS=1024 NUMA PowerNV
  task: c000000004294b80 ti: c0000007e1a78000 task.ti: c0000007e1a78000
  NIP: 0000000000000000 LR: 0000000000009c14 CTR: c000000000423140
  REGS: c0000007e1a7b920 TRAP: 0e40   Not tainted  (3.18.17-340.el7_1.pkvm3_1_0.2400.1.ppc64le)
  MSR: 1000000000081000 <HV,ME>  CR: 00000000  XER: 00000000
  CFAR: c000000000009c0c SOFTE: 0
  NIP [0000000000000000]           (null)
  LR [0000000000009c14] 0x9c14
  Call Trace:
  [c0000007e1a7bba0] [c00000000041a7f4] avc_has_perm_noaudit+0x54/0x110 (unreliable)
  [c0000007e1a7bd80] [c00000000002ddc0] ppc_rtas+0x150/0x2d0
  [c0000007e1a7be30] [c000000000009358] syscall_exit+0x0/0x98

Cc: stable@vger.kernel.org # v3.2+
Fixes: 55190f8878 ("powerpc: Add skeleton PowerNV platform")
Reported-by: NAGESWARA R. SASTRY <nasastry@in.ibm.com>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: Reword change log, trim oops, and add stable + fixes]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-22 11:03:25 +11:00
Thomas Huth 1c2cb59444 powerpc/rtas: Introduce rtas_get_sensor_fast() for IRQ handlers
The EPOW interrupt handler uses rtas_get_sensor(), which in turn
uses rtas_busy_delay() to wait for RTAS becoming ready in case it
is necessary. But rtas_busy_delay() is annotated with might_sleep()
and thus may not be used by interrupts handlers like the EPOW handler!
This leads to the following BUG when CONFIG_DEBUG_ATOMIC_SLEEP is
enabled:

 BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:496
 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1
 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.2.0-rc2-thuth #6
 Call Trace:
 [c00000007ffe7b90] [c000000000807670] dump_stack+0xa0/0xdc (unreliable)
 [c00000007ffe7bc0] [c0000000000e1f14] ___might_sleep+0x134/0x180
 [c00000007ffe7c20] [c00000000002aec0] rtas_busy_delay+0x30/0xd0
 [c00000007ffe7c50] [c00000000002bde4] rtas_get_sensor+0x74/0xe0
 [c00000007ffe7ce0] [c000000000083264] ras_epow_interrupt+0x44/0x450
 [c00000007ffe7d90] [c000000000120260] handle_irq_event_percpu+0xa0/0x300
 [c00000007ffe7e70] [c000000000120524] handle_irq_event+0x64/0xc0
 [c00000007ffe7eb0] [c000000000124dbc] handle_fasteoi_irq+0xec/0x260
 [c00000007ffe7ef0] [c00000000011f4f0] generic_handle_irq+0x50/0x80
 [c00000007ffe7f20] [c000000000010f3c] __do_irq+0x8c/0x200
 [c00000007ffe7f90] [c0000000000236cc] call_do_irq+0x14/0x24
 [c00000007e6f39e0] [c000000000011144] do_IRQ+0x94/0x110
 [c00000007e6f3a30] [c000000000002594] hardware_interrupt_common+0x114/0x180

Fix this issue by introducing a new rtas_get_sensor_fast() function
that does not use rtas_busy_delay() - and thus can only be used for
sensors that do not cause a BUSY condition - known as "fast" sensors.

The EPOW sensor is defined to be "fast" in sPAPR - mpe.

Fixes: 587f83e8dd ("powerpc/pseries: Use rtas_get_sensor in RAS code")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-07-23 19:43:11 +10:00
Thomas Huth 9ef03193a9 powerpc/rtas: Replace magic values with defines
rtas.h already has some nice #defines for RTAS return status
codes - let's use them instead of hard-coded "magic" values!

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-07-23 16:27:05 +10:00
Michael Ellerman f691fa1080 powerpc: Replace mem_init_done with slab_is_available()
We have a powerpc specific global called mem_init_done which is "set on
boot once kmalloc can be called".

But that's not *quite* true. We set it at the bottom of mem_init(), and
rely on the fact that mm_init() calls kmem_cache_init() immediately
after that, and nothing is running in parallel.

So replace it with the generic and 100% correct slab_is_available().

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-04-10 20:02:48 +10:00
Tyrel Datwyler c03e73740d powerpc/pseries: Simplify check for suspendability during suspend/migration
During suspend/migration operation we must wait for the VASI state reported
by the hypervisor to become Suspending prior to making the ibm,suspend-me
RTAS call. Calling routines to rtas_ibm_supend_me() pass a vasi_state variable
that exposes the VASI state to the caller. This is unnecessary as the caller
only really cares about the following three conditions; if there is an error
we should bailout, success indicating we have suspended and woken back up so
proceed to device tree update, or we are not suspendable yet so try calling
rtas_ibm_suspend_me again shortly.

This patch removes the extraneous vasi_state variable and simply uses the
return code to communicate how to proceed. We either succeed, fail, or get
-EAGAIN in which case we sleep for a second before trying to call
rtas_ibm_suspend_me again. The behaviour of ppc_rtas() remains the same,
but migrate_store() now returns the propogated error code on failure.
Previously -1 was returned from migrate_store() in the  failure case which
equates to -EPERM and was clearly wrong.

Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Cc: Nathan Fontenont <nfont@linux.vnet.ibm.com>
Cc: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-28 12:20:39 +11:00
Cyril Bur 3df76a9dcc powerpc/pseries: Fix endian problems with LE migration
RTAS events require arguments be passed in big endian while hypercalls
have their arguments passed in registers and the values should therefore
be in CPU endian.

The "ibm,suspend_me" 'RTAS' call makes a sequence of hypercalls to setup
one true RTAS call. This means that "ibm,suspend_me" is handled
specially in the ppc_rtas() syscall.

The ppc_rtas() syscall has its arguments in big endian and can therefore
pass these arguments directly to the RTAS call. "ibm,suspend_me" is
handled specially from within ppc_rtas() (by calling rtas_ibm_suspend_me())
which has left an endian bug on little endian systems due to the
requirement of hypercalls. The return value from rtas_ibm_suspend_me()
gets returned in cpu endian, and is left unconverted, also a bug on
little endian systems.

rtas_ibm_suspend_me() does not actually make use of the rtas_args that
it is passed. This patch removes the convoluted use of the rtas_args
struct to pass params to rtas_ibm_suspend_me() in favour of passing what
it needs as actual arguments. This patch also ensures the two callers of
rtas_ibm_suspend_me() pass function parameters in cpu endian and in the
case of ppc_rtas(), converts the return value.

migrate_store() (the other caller of rtas_ibm_suspend_me()) is from a
sysfs file which deals with everything in cpu endian so this function
only underwent cleanup.

This patch has been tested with KVM both LE and BE and on PowerVM both
LE and BE. Under QEMU/KVM the migration happens without touching these
code pathes.

For PowerVM there is no obvious regression on BE and the LE code path
now provides the correct parameters to the hypervisor.

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-01-27 14:03:53 +11:00
Anton Blanchard 14ed740957 powerpc: Remove some old bootmem related comments
Now bootmem is gone from powerpc we can remove comments mentioning it.

Signed-off-by: Anton Blanchard <anton@samba.org>
Tested-by: Emil Medve <Emilian.Medve@Freescale.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-10 09:59:25 +11:00
Rob Herring 9d0c4dfedd of/fdt: update of_get_flat_dt_prop in prep for libfdt
Make of_get_flat_dt_prop arguments compatible with libfdt fdt_getprop
call in preparation to convert FDT code to use libfdt. Make the return
value const and the property length ptr type an int.

Signed-off-by: Rob Herring <robh@kernel.org>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Tested-by: Grant Likely <grant.likely@linaro.org>
Tested-by: Stephen Chivers <schivers@csc.com>
2014-04-30 00:59:15 -05:00
Greg Kurz a08a53ea4c powerpc/le: Enable RTAS events support
The current kernel code assumes big endian and parses RTAS events all
wrong. The most visible effect is that we cannot honor EPOW events,
meaning, for example, we cannot shut down a guest properly from the
hypervisor.

This new patch is largely inspired by Nathan's work: we get rid of all
the bit fields in the RTAS event structures (even the unused ones, for
consistency). We also introduce endian safe accessors for the fields used
by the kernel (trivial rtas_error_type() accessor added for consistency).

Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-07 10:33:12 +10:00
Greg Kurz 599d287042 powerpc/le: Big endian arguments for ppc_rtas()
The ppc_rtas() syscall allows userspace to interact directly with RTAS.
For the moment, it assumes every thing is big endian and returns either
EINVAL or EFAULT when called in a little endian environment.

As suggested by Benjamin, to avoid bugs when userspace wants to pass
a non 32 bit value to RTAS, it is far better to stick with a simple
rationale: ppc_rtas() should be called with a big endian rtas_args
structure.

With this patch, it is now up to userspace to forge big endian arguments,
as expected by RTAS.

Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-03-24 09:48:36 +11:00
Anton Blanchard 2712826491 powerpc: Make RTAS calls endian safe
RTAS expects arguments in the call buffer to be big endian so we
need to byteswap on little endian builds

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-14 15:33:22 +10:00
Anton Blanchard 08bc1dc51f powerpc: Make RTAS device tree accesses endian safe
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-14 15:33:20 +10:00
Paul Gortmaker 061d19f279 powerpc: Delete __cpuinit usage from all users
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the powerpc uses of the __cpuinit macros.  There
are no __CPUINIT users in assembly files in powerpc.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01 11:10:36 +10:00
Robert Jennings 120496ac2d powerpc: Bring all threads online prior to migration/hibernation
This patch brings online all threads which are present but not online
prior to migration/hibernation.  After migration/hibernation those
threads are taken back offline.

During migration/hibernation all online CPUs must call H_JOIN, this is
required by the hypervisor.  Without this patch, threads that are offline
(H_CEDE'd) will not be woken to make the H_JOIN call and the OS will be
deadlocked (all threads either JOIN'd or CEDE'd).

Cc: <stable@kernel.org>
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 14:36:29 +10:00
Nathan Fontenot f459d63e16 powerpc+of: Remove the pSeries_reconfig.h file
Remove the pSeries_reconfig.h header file. At this point there is only one
definition in the file, pSeries_coalesce_init(), which can be
moved to rtas.h.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-11-15 12:56:55 +11:00
Linus Torvalds 0195c00244 Disintegrate and delete asm/system.h
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...
2012-03-28 15:58:21 -07:00
David Howells ae3a197e3d Disintegrate asm/system.h for PowerPC
Disintegrate asm/system.h for PowerPC.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
cc: linuxppc-dev@lists.ozlabs.org
2012-03-28 18:30:02 +01:00
Anton Blanchard 6431f20879 powerpc: Make function that parses RTAS error logs global
The IO event interrupt code has a function that finds specific
sections in an RTAS error log. We want to use it in the EPOW
code so make it global.

Rename things to make it less cryptic:

find_xelog_section() -> get_pseries_errorlog()
struct pseries_elog_section -> struct pseries_errorlog

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-28 11:31:58 +11:00
Brian King 444080d13d powerpc/pseries: Fix partition migration hang in stop_topology_update
This fixes a hang that was observed during live partition migration.
Since stop_topology_update must not be called from an interrupt
context, call it earlier in the migration process. The hang observed
can be seen below:

WARNING: at kernel/timer.c:1011
Modules linked in: ip6t_LOG xt_tcpudp xt_pkttype ipt_LOG xt_limit ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_raw xt_NOTRACK ipt_REJECT xt_state iptable_raw iptable_filter ip6table_mangle nf_conntrack_netbios_ns nf_conntrack_broadcast nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 ip_tables ip6table_filter ip6_tables x_tables ipv6 fuse loop ibmveth sg ext3 jbd mbcache raid456 async_raid6_recov async_pq raid6_pq async_xor xor async_memcpy async_tx raid10 raid1 raid0 scsi_dh_alua scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc dm_round_robin dm_multipath scsi_dh sd_mod crc_t10dif ibmvfc scsi_transport_fc scsi_tgt scsi_mod dm_snapshot dm_mod
NIP: c0000000000c52d8 LR: c00000000004be28 CTR: 0000000000000000
REGS: c00000005ffd77d0 TRAP: 0700   Not tainted  (3.2.0-git-00001-g07d106d)
MSR: 8000000000021032 <ME,CE,IR,DR>  CR: 48000084  XER: 00000001
CFAR: c00000000004be20
TASK = c00000005ec78860[0] 'swapper/3' THREAD: c00000005ec98000 CPU: 3
GPR00: 0000000000000001 c00000005ffd7a50 c000000000fbbc98 c000000000ec8340
GPR04: 00000000282a0020 0000000000000000 0000000000004000 0000000000000101
GPR08: 0000000000000012 c00000005ffd4000 0000000000000020 c000000000f3ba88
GPR12: 0000000000000000 c000000007f40900 0000000000000001 0000000000000004
GPR16: 0000000000000001 0000000000000000 0000000000000000 c000000001022310
GPR20: 0000000000000001 0000000000000000 0000000000200200 c000000001029e14
GPR24: 0000000000000000 0000000000000001 0000000000000040 c00000003f74bc80
GPR28: c00000003f74bc84 c000000000f38038 c000000000f16b58 c000000000ec8340
NIP [c0000000000c52d8] .del_timer_sync+0x28/0x60
LR [c00000000004be28] .stop_topology_update+0x20/0x38
Call Trace:
[c00000005ffd7a50] [c00000005ec78860] 0xc00000005ec78860 (unreliable)
[c00000005ffd7ad0] [c00000000004be28] .stop_topology_update+0x20/0x38
[c00000005ffd7b40] [c000000000028378] .__rtas_suspend_last_cpu+0x58/0x260
[c00000005ffd7bf0] [c0000000000fa230] .generic_smp_call_function_interrupt+0x160/0x358
[c00000005ffd7cf0] [c000000000036ec8] .smp_ipi_demux+0x88/0x100
[c00000005ffd7d80] [c00000000005c154] .icp_hv_ipi_action+0x5c/0x80
[c00000005ffd7e00] [c00000000012a088] .handle_irq_event_percpu+0x100/0x318
[c00000005ffd7f00] [c00000000012e774] .handle_percpu_irq+0x84/0xd0
[c00000005ffd7f90] [c000000000022ba8] .call_handle_irq+0x1c/0x2c
[c00000005ec9ba20] [c00000000001157c] .do_IRQ+0x22c/0x2a8
[c00000005ec9bae0] [c0000000000054bc] hardware_interrupt_entry+0x18/0x1c
Exception: 501 at .cpu_idle+0x194/0x2f8
    LR = .cpu_idle+0x194/0x2f8
[c00000005ec9bdd0] [c000000000017e58] .cpu_idle+0x188/0x2f8 (unreliable)
[c00000005ec9be90] [c00000000067ec18] .start_secondary+0x3e4/0x524
[c00000005ec9bf90] [c0000000000093e8] .start_secondary_prolog+0x10/0x14
Instruction dump:
ebe1fff8 4e800020 fbe1fff8 7c0802a6 f8010010 7c7f1b78 f821ff81 78290464
80090014 5400019e 7c0000d0 78000fe0 <0b000000> 4800000c 7c210b78 7c421378

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-02-14 15:01:39 +11:00
Paul Gortmaker 4b16f8e2d6 powerpc: various straight conversions from module.h --> export.h
All these files were including module.h just for the basic
EXPORT_SYMBOL infrastructure.  We can shift them off to the
export.h header which is a way smaller footprint and thus
realize some compile time gains.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:44 -04:00