Commit Graph

1862 Commits

Author SHA1 Message Date
Linus Torvalds c90fca951e powerpc updates for 4.18
Notable changes:
 
  - Support for split PMD page table lock on 64-bit Book3S (Power8/9).
 
  - Add support for HAVE_RELIABLE_STACKTRACE, so we properly support live
    patching again.
 
  - Add support for patching barrier_nospec in copy_from_user() and syscall entry.
 
  - A couple of fixes for our data breakpoints on Book3S.
 
  - A series from Nick optimising TLB/mm handling with the Radix MMU.
 
  - Numerous small cleanups to squash sparse/gcc warnings from Mathieu Malaterre.
 
  - Several series optimising various parts of the 32-bit code from Christophe Leroy.
 
  - Removal of support for two old machines, "SBC834xE" and "C2K" ("GEFanuc,C2K"),
    which is why the diffstat has so many deletions.
 
 And many other small improvements & fixes.
 
 There's a few out-of-area changes. Some minor ftrace changes OK'ed by Steve, and
 a fix to our powernv cpuidle driver. Then there's a series touching mm, x86 and
 fs/proc/task_mmu.c, which cleans up some details around pkey support. It was
 ack'ed/reviewed by Ingo & Dave and has been in next for several weeks.
 
 Thanks to:
   Akshay Adiga, Alastair D'Silva, Alexey Kardashevskiy, Al Viro, Andrew
   Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Balbir Singh,
   Cédric Le Goater, Christophe Leroy, Christophe Lombard, Colin Ian King, Dave
   Hansen, Fabio Estevam, Finn Thain, Frederic Barrat, Gautham R. Shenoy, Haren
   Myneni, Hari Bathini, Ingo Molnar, Jonathan Neuschäfer, Josh Poimboeuf,
   Kamalesh Babulal, Madhavan Srinivasan, Mahesh Salgaonkar, Mark Greer, Mathieu
   Malaterre, Matthew Wilcox, Michael Neuling, Michal Suchanek, Naveen N. Rao,
   Nicholas Piggin, Nicolai Stange, Olof Johansson, Paul Gortmaker, Paul
   Mackerras, Peter Rosin, Pridhiviraj Paidipeddi, Ram Pai, Rashmica Gupta, Ravi
   Bangoria, Russell Currey, Sam Bobroff, Samuel Mendoza-Jonas, Segher
   Boessenkool, Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stewart Smith,
   Thiago Jung Bauermann, Torsten Duwe, Vaibhav Jain, Wei Yongjun, Wolfram Sang,
   Yisheng Xie, YueHaibing.
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Merge tag 'powerpc-4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Support for split PMD page table lock on 64-bit Book3S (Power8/9).

   - Add support for HAVE_RELIABLE_STACKTRACE, so we properly support
     live patching again.

   - Add support for patching barrier_nospec in copy_from_user() and
     syscall entry.

   - A couple of fixes for our data breakpoints on Book3S.

   - A series from Nick optimising TLB/mm handling with the Radix MMU.

   - Numerous small cleanups to squash sparse/gcc warnings from Mathieu
     Malaterre.

   - Several series optimising various parts of the 32-bit code from
     Christophe Leroy.

   - Removal of support for two old machines, "SBC834xE" and "C2K"
     ("GEFanuc,C2K"), which is why the diffstat has so many deletions.

  And many other small improvements & fixes.

  There's a few out-of-area changes. Some minor ftrace changes OK'ed by
  Steve, and a fix to our powernv cpuidle driver. Then there's a series
  touching mm, x86 and fs/proc/task_mmu.c, which cleans up some details
  around pkey support. It was ack'ed/reviewed by Ingo & Dave and has
  been in next for several weeks.

  Thanks to: Akshay Adiga, Alastair D'Silva, Alexey Kardashevskiy, Al
  Viro, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Arnd
  Bergmann, Balbir Singh, Cédric Le Goater, Christophe Leroy, Christophe
  Lombard, Colin Ian King, Dave Hansen, Fabio Estevam, Finn Thain,
  Frederic Barrat, Gautham R. Shenoy, Haren Myneni, Hari Bathini, Ingo
  Molnar, Jonathan Neuschäfer, Josh Poimboeuf, Kamalesh Babulal,
  Madhavan Srinivasan, Mahesh Salgaonkar, Mark Greer, Mathieu Malaterre,
  Matthew Wilcox, Michael Neuling, Michal Suchanek, Naveen N. Rao,
  Nicholas Piggin, Nicolai Stange, Olof Johansson, Paul Gortmaker, Paul
  Mackerras, Peter Rosin, Pridhiviraj Paidipeddi, Ram Pai, Rashmica
  Gupta, Ravi Bangoria, Russell Currey, Sam Bobroff, Samuel
  Mendoza-Jonas, Segher Boessenkool, Shilpasri G Bhat, Simon Guo,
  Souptick Joarder, Stewart Smith, Thiago Jung Bauermann, Torsten Duwe,
  Vaibhav Jain, Wei Yongjun, Wolfram Sang, Yisheng Xie, YueHaibing"

* tag 'powerpc-4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (251 commits)
  powerpc/64s/radix: Fix missing ptesync in flush_cache_vmap
  cpuidle: powernv: Fix promotion from snooze if next state disabled
  powerpc: fix build failure by disabling attribute-alias warning in pci_32
  ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()
  powerpc-opal: fix spelling mistake "Uniterrupted" -> "Uninterrupted"
  powerpc: fix spelling mistake: "Usupported" -> "Unsupported"
  powerpc/pkeys: Detach execute_only key on !PROT_EXEC
  powerpc/powernv: copy/paste - Mask SO bit in CR
  powerpc: Remove core support for Marvell mv64x60 hostbridges
  powerpc/boot: Remove core support for Marvell mv64x60 hostbridges
  powerpc/boot: Remove support for Marvell mv64x60 i2c controller
  powerpc/boot: Remove support for Marvell MPSC serial controller
  powerpc/embedded6xx: Remove C2K board support
  powerpc/lib: optimise PPC32 memcmp
  powerpc/lib: optimise 32 bits __clear_user()
  powerpc/time: inline arch_vtime_task_switch()
  powerpc/Makefile: set -mcpu=860 flag for the 8xx
  powerpc: Implement csum_ipv6_magic in assembly
  powerpc/32: Optimise __csum_partial()
  powerpc/lib: Adjust .balign inside string functions for PPC32
  ...
2018-06-07 10:23:33 -07:00
Ram Pai eabdb8ca86 powerpc/pkeys: Detach execute_only key on !PROT_EXEC
Disassociate the exec_key from a VMA if the VMA permission is not
PROT_EXEC anymore. Otherwise the exec_only key continues to be
associated with the vma, causing unexpected behavior.

The problem was reported on x86 by Shakeel Butt, which is also
applicable on powerpc.

Fixes: 5586cf61e1 ("powerpc: introduce execute-only pkey")
Cc: stable@vger.kernel.org # v4.16+
Reported-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-05 11:03:25 +10:00
Linus Torvalds 93e95fa574 Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull siginfo updates from Eric Biederman:
 "This set of changes close the known issues with setting si_code to an
  invalid value, and with not fully initializing struct siginfo. There
  remains work to do on nds32, arc, unicore32, powerpc, arm, arm64, ia64
  and x86 to get the code that generates siginfo into a simpler and more
  maintainable state. Most of that work involves refactoring the signal
  handling code and thus careful code review.

  Also not included is the work to shrink the in kernel version of
  struct siginfo. That depends on getting the number of places that
  directly manipulate struct siginfo under control, as it requires the
  introduction of struct kernel_siginfo for the in kernel things.

  Overall this set of changes looks like it is making good progress, and
  with a little luck I will be wrapping up the siginfo work next
  development cycle"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
  signal/sh: Stop gcc warning about an impossible case in do_divide_error
  signal/mips: Report FPE_FLTUNK for undiagnosed floating point exceptions
  signal/um: More carefully relay signals in relay_signal.
  signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR}
  signal: Remove unncessary #ifdef SEGV_PKUERR in 32bit compat code
  signal/signalfd: Add support for SIGSYS
  signal/signalfd: Remove __put_user from signalfd_copyinfo
  signal/xtensa: Use force_sig_fault where appropriate
  signal/xtensa: Consistenly use SIGBUS in do_unaligned_user
  signal/um: Use force_sig_fault where appropriate
  signal/sparc: Use force_sig_fault where appropriate
  signal/sparc: Use send_sig_fault where appropriate
  signal/sh: Use force_sig_fault where appropriate
  signal/s390: Use force_sig_fault where appropriate
  signal/riscv: Replace do_trap_siginfo with force_sig_fault
  signal/riscv: Use force_sig_fault where appropriate
  signal/parisc: Use force_sig_fault where appropriate
  signal/parisc: Use force_sig_mceerr where appropriate
  signal/openrisc: Use force_sig_fault where appropriate
  signal/nios2: Use force_sig_fault where appropriate
  ...
2018-06-04 15:23:48 -07:00
Christophe Leroy c865c95587 powerpc/mm: Remove stale_map[] handling on non SMP processors
stale_map[] bits are only set in steal_context_smp() so
on UP processors this map is useless. Only manage it for SMP
processors.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-04 00:39:16 +10:00
Christophe Leroy 9e4f02e24e powerpc/mm: constify LAST_CONTEXT in mmu_context_nohash
last_context is 16 on the 8xx, 65535 on the 47x and 255 on other ones.

The kernel is exclusively built for the 8xx, for the 47x or for
another processor so the last context can be defined as a constant
depending on the processor.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Reformat old comment]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-04 00:39:16 +10:00
Christophe Leroy 48bdcace59 powerpc/mm: Avoid unnecessary test and reduce code size
no_selective_tlbil hence the use of either steal_all_contexts()
or steal_context_up() depends on the subarch, it won't change
during run. Only the 8xx uses steal_all_contexts and CONFIG_PPC_8xx
is exclusive of other processors.

This patch replaces the test of no_selective_tlbil global var by
a test of CONFIG_PPC_8xx selection. It avoids the test and
removes unnecessary code.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-04 00:39:15 +10:00
Christophe Leroy 8820a44738 powerpc/mm: constify FIRST_CONTEXT in mmu_context_nohash
First context is now 1 for all supported platforms, so it
can be made a constant.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-04 00:39:15 +10:00
Aneesh Kumar K.V a5db5060e0 powerpc/mm/hash: hard disable irq in the SLB insert path
When inserting SLB entries for EA above 512TB, we need to hard disable irq.
This will make sure we don't take a PMU interrupt that can possibly touch
user space address via a stack dump. To prevent this, we need to hard disable
the interrupt.

Also add a comment explaining why we don't need context synchronizing isync
with slbmte.

Fixes: f384796c4 ("powerpc/mm: Add support for handling > 512TB address in SLB miss")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:38 +10:00
Aneesh Kumar K.V ed515b6898 powerpc/mm/hugetlb: Update hugetlb related locks
With split pmd page table lock enabled, we don't use mm->page_table_lock when
updating pmd entries. This patch update hugetlb path to use the right lock
when inserting huge page directory entries into page table.

ex: if we are using hugepd and inserting hugepd entry at the pmd level, we
use pmd_lockptr, which based on config can be split pmd lock.

For update huge page directory entries itself we use mm->page_table_lock. We
do have a helper huge_pte_lockptr() for that.

Fixes: 675d99529 ("powerpc/book3s64: Enable split pmd ptlock")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:37 +10:00
Nicholas Piggin 926bc2f100 powerpc/64s: Fix compiler store ordering to SLB shadow area
The stores to update the SLB shadow area must be made as they appear
in the C code, so that the hypervisor does not see an entry with
mismatched vsid and esid. Use WRITE_ONCE for this.

GCC has been observed to elide the first store to esid in the update,
which means that if the hypervisor interrupts the guest after storing
to vsid, it could see an entry with old esid and new vsid, which may
possibly result in memory corruption.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:37 +10:00
Nicholas Piggin 0cef77c779 powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask
When a single-threaded process has a non-local mm_cpumask, try to use
that point to flush the TLBs out of other CPUs in the cpumask.

An IPI is used for clearing remote CPUs for a few reasons:
- An IPI can end lazy TLB use of the mm, which is required to prevent
  TLB entries being created on the remote CPU. The alternative is to
  drop lazy TLB switching completely, which costs 7.5% in a context
  switch ping-pong test betwee a process and kernel idle thread.
- An IPI can have remote CPUs flush the entire PID, but the local CPU
  can flush a specific VA. tlbie would require over-flushing of the
  local CPU (where the process is running).
- A single threaded process that is migrated to a different CPU is
  likely to have a relatively small mm_cpumask, so IPI is reasonable.

No other thread can concurrently switch to this mm, because it must
have been given a reference to mm_users by the current thread before it
can use_mm. mm_users can be asynchronously incremented (by
mm_activate or mmget_not_zero), but those users must use remote mm
access and can't use_mm or access user address space. Existing code
makes the this assumption already, for example sparc64 has reset
mm_cpumask using this condition since the start of history, see
arch/sparc/kernel/smp_64.c.

This reduces tlbies for a kernel compile workload from 0.90M to 0.12M,
tlbiels are increased significantly due to the PID flushing for the
cleaning up remote CPUs, and increased local flushes (PID flushes take
128 tlbiels vs 1 tlbie).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:36 +10:00
Nicholas Piggin 85bcfaf69c powerpc/64s/radix: optimise pte_update
Implementing pte_update with pte_xchg (which uses cmpxchg) is
inefficient. A single larx/stcx. works fine, no need for the less
efficient cmpxchg sequence.

Then remove the memory barriers from the operation. There is a
requirement for TLB flushing to load mm_cpumask after the store
that reduces pte permissions, which is moved into the TLB flush
code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:36 +10:00
Nicholas Piggin f1cb8f9beb powerpc/64s/radix: avoid ptesync after set_pte and ptep_set_access_flags
The ISA suggests ptesync after setting a pte, to prevent a table walk
initiated by a subsequent access from missing that store and causing a
spurious fault. This is an architectual allowance that allows an
implementation's page table walker to be incoherent with the store
queue.

However there is no correctness problem in taking a spurious fault in
userspace -- the kernel copes with these at any time, so the updated
pte will be found eventually. Spurious kernel faults on vmap memory
must be avoided, so a ptesync is put into flush_cache_vmap.

On POWER9 so far I have not found a measurable window where this can
result in more minor faults, so as an optimisation, remove the costly
ptesync from pte updates. If an implementation benefits from ptesync,
it would be better to add it back in update_mmu_cache, so it's not
done for things like fork(2).

fork --fork --exec benchmark improved 5.2% (12400->13100).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:36 +10:00
Nicholas Piggin 68662f85f3 powerpc/64s/radix: prefetch user address in update_mmu_cache
Prefetch the faulting address in update_mmu_cache to give the page
table walker perhaps 100 cycles head start as locks are dropped and
the interrupt completed.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:35 +10:00
Nicholas Piggin e5f7cb58c2 powerpc/64s/radix: do not flush TLB when relaxing access
Radix flushes the TLB when updating ptes to increase permissiveness
of protection (increase access authority). Book3S does not require
TLB flushing in this case, and it is not done on hash. This patch
avoids the flush for radix.

>From Power ISA v3.0B, p.1090:

    Setting a Reference or Change Bit or Upgrading Access Authority
    (PTE Subject to Atomic Hardware Updates)

    If the only change being made to a valid PTE that is subject to
    atomic hardware updates is to set the Reference or Change bit to 1
    or to add access authorities, a simpler sequence suffices because
    the translation hardware will refetch the PTE if an access is
    attempted for which the only problems were reference and/or change
    bits needing to be set or insufficient access authority.

The nest MMU on POWER9 does not re-fetch the PTE after such an access
attempt before faulting, so address spaces with a coprocessor
attached will continue to flush in these cases.

This reduces tlbies for a kernel compile workload from 1.28M to 0.95M,
tlbiels from 20.17M 19.68M.

fork --fork --exec benchmark improved 2.77% (12000->12300).

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:34 +10:00
Aneesh Kumar K.V bd5050e38a powerpc/mm/radix: Change pte relax sequence to handle nest MMU hang
When relaxing access (read -> read_write update), pte needs to be marked invalid
to handle a nest MMU bug. We also need to do a tlb flush after the pte is
marked invalid before updating the pte with new access bits.

We also move tlb flush to platform specific __ptep_set_access_flags. This will
help us to gerid of unnecessary tlb flush on BOOK3S 64 later. We don't do that
in this patch. This also helps in avoiding multiple tlbies with coprocessor
attached.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:34 +10:00
Aneesh Kumar K.V e4c1112c3f powerpc/mm: Change function prototype
In later patch, we use the vma and psize to do tlb flush. Do the prototype
update in separate patch to make the review easy.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:34 +10:00
Aneesh Kumar K.V 044003b52a powerpc/mm/radix: Move function from radix.h to pgtable-radix.c
In later patch we will update them which require them to be moved
to pgtable-radix.c. Keeping the function in radix.h results in
compile warning as below.

./arch/powerpc/include/asm/book3s/64/radix.h: In function ‘radix__ptep_set_access_flags’:
./arch/powerpc/include/asm/book3s/64/radix.h:196:28: error: dereferencing pointer to incomplete type ‘struct vm_area_struct’
  struct mm_struct *mm = vma->vm_mm;
                            ^~
./arch/powerpc/include/asm/book3s/64/radix.h:204:6: error: implicit declaration of function ‘atomic_read’; did you mean ‘__atomic_load’? [-Werror=implicit-function-declaration]
      atomic_read(&mm->context.copros) > 0) {
      ^~~~~~~~~~~
      __atomic_load
./arch/powerpc/include/asm/book3s/64/radix.h:204:21: error: dereferencing pointer to incomplete type ‘struct mm_struct’
      atomic_read(&mm->context.copros) > 0) {

Instead of fixing header dependencies, we move the function to pgtable-radix.c
Also the function is now large to be a static inline . Doing the
move in separate patch helps in review.

No functional change in this patch. Only code movement.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:34 +10:00
Aneesh Kumar K.V f069ff396d powerpc/mm/hugetlb: Update huge_ptep_set_access_flags to call __ptep_set_access_flags directly
In a later patch, we want to update __ptep_set_access_flags take page size
arg. This makes ptep_set_access_flags only work with mmu_virtual_psize.
To simplify the code make huge_ptep_set_access_flags directly call
__ptep_set_access_flags so that we can compute the hugetlb page size in
hugetlb function.

Now that ptep_set_access_flags won't be called for hugetlb remove
the is_vm_hugetlb_page() check and add the assert of pte lock
unconditionally.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:33 +10:00
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
Michael Ellerman 481c63acba Merge branch 'topic/ppc-kvm' into next
Merge in some commits we're sharing with the kvm-ppc tree.
2018-06-03 20:23:54 +10:00
Mathieu Malaterre d8731527ac powerpc/sparse: Fix plain integer as NULL pointer warning
Trivial fix to remove the following sparse warnings:

  arch/powerpc/kernel/module_32.c:112:74: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/module_32.c:117:74: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1155:28: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1230:20: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1385:36: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:1752:23: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2084:19: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2110:32: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2167:19: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:2183:19: warning: Using plain integer as NULL pointer
  drivers/macintosh/via-pmu.c:277:20: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:155:67: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:247:27: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:249:27: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/setup.c:252:37: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:127:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:148:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:44:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:57:21: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/tlb_hash32.c:87:21: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:160:31: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:167:22: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:274:21: warning: Using plain integer as NULL pointer
  arch/powerpc/kernel/btext.c:285:31: warning: Using plain integer as NULL pointer
  arch/powerpc/include/asm/hugetlb.h:204:16: warning: Using plain integer as NULL pointer
  arch/powerpc/mm/ppc_mmu_32.c:170:21: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/pci.c:1227:23: warning: Using plain integer as NULL pointer
  arch/powerpc/platforms/powermac/pci.c:65:24: warning: Using plain integer as NULL pointer

Also use `--fix` command line option from `script/checkpatch --strict` to
remove the following:

  CHECK: Comparison to NULL could be written "!dispDeviceBase"
  #72: FILE: arch/powerpc/kernel/btext.c:160:
  +	if (dispDeviceBase == NULL)

  CHECK: Comparison to NULL could be written "!vbase"
  #80: FILE: arch/powerpc/kernel/btext.c:167:
  +	if (vbase == NULL)

  CHECK: Comparison to NULL could be written "!base"
  #89: FILE: arch/powerpc/kernel/btext.c:274:
  +	if (base == NULL)

  CHECK: Comparison to NULL could be written "!dispDeviceBase"
  #98: FILE: arch/powerpc/kernel/btext.c:285:
  +	if (dispDeviceBase == NULL)

  CHECK: Comparison to NULL could be written "strstr"
  #117: FILE: arch/powerpc/kernel/module_32.c:117:
  +		if (strstr(secstrings + sechdrs[i].sh_name, ".debug") != NULL)

  CHECK: Comparison to NULL could be written "!Hash"
  #130: FILE: arch/powerpc/mm/ppc_mmu_32.c:170:
  +	if (Hash == NULL)

  CHECK: Comparison to NULL could be written "Hash"
  #143: FILE: arch/powerpc/mm/tlb_hash32.c:44:
  +	if (Hash != NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #152: FILE: arch/powerpc/mm/tlb_hash32.c:57:
  +	if (Hash == NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #161: FILE: arch/powerpc/mm/tlb_hash32.c:87:
  +	if (Hash == NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #170: FILE: arch/powerpc/mm/tlb_hash32.c:127:
  +	if (Hash == NULL) {

  CHECK: Comparison to NULL could be written "!Hash"
  #179: FILE: arch/powerpc/mm/tlb_hash32.c:148:
  +	if (Hash == NULL) {

  ERROR: space required after that ';' (ctx:VxV)
  #192: FILE: arch/powerpc/platforms/powermac/pci.c:65:
  +	for (; node != NULL;node = node->sibling) {

  CHECK: Comparison to NULL could be written "node"
  #192: FILE: arch/powerpc/platforms/powermac/pci.c:65:
  +	for (; node != NULL;node = node->sibling) {

  CHECK: Comparison to NULL could be written "!region"
  #201: FILE: arch/powerpc/platforms/powermac/pci.c:1227:
  +	if (region == NULL)

  CHECK: Comparison to NULL could be written "of_get_property"
  #214: FILE: arch/powerpc/platforms/powermac/setup.c:155:
  +		if (of_get_property(np, "cache-unified", NULL) != NULL && dc) {

  CHECK: Comparison to NULL could be written "!np"
  #223: FILE: arch/powerpc/platforms/powermac/setup.c:247:
  +		if (np == NULL)

  CHECK: Comparison to NULL could be written "np"
  #226: FILE: arch/powerpc/platforms/powermac/setup.c:249:
  +		if (np != NULL) {

  CHECK: Comparison to NULL could be written "l2cr"
  #230: FILE: arch/powerpc/platforms/powermac/setup.c:252:
  +			if (l2cr != NULL) {

  CHECK: Comparison to NULL could be written "via"
  #243: FILE: drivers/macintosh/via-pmu.c:277:
  +	if (via != NULL)

  CHECK: Comparison to NULL could be written "current_req"
  #252: FILE: drivers/macintosh/via-pmu.c:1155:
  +	if (current_req != NULL) {

  CHECK: Comparison to NULL could be written "!req"
  #261: FILE: drivers/macintosh/via-pmu.c:1230:
  +	if (req == NULL || pmu_state != idle

  CHECK: Comparison to NULL could be written "!req"
  #270: FILE: drivers/macintosh/via-pmu.c:1385:
  +			if (req == NULL) {

  CHECK: Comparison to NULL could be written "!pp"
  #288: FILE: drivers/macintosh/via-pmu.c:2084:
  +	if (pp == NULL)

  CHECK: Comparison to NULL could be written "!pp"
  #297: FILE: drivers/macintosh/via-pmu.c:2110:
  +	if (count < 1 || pp == NULL)

  CHECK: Comparison to NULL could be written "!pp"
  #306: FILE: drivers/macintosh/via-pmu.c:2167:
  +	if (pp == NULL)

  CHECK: Comparison to NULL could be written "pp"
  #315: FILE: drivers/macintosh/via-pmu.c:2183:
  +	if (pp != NULL) {

Link: https://github.com/linuxppc/linux/issues/37
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-25 12:04:38 +10:00
Christophe Leroy 0e36b0d125 powerpc/mm: Only read faulting instruction when necessary in do_page_fault()
Commit a7a9dcd882 ("powerpc: Avoid taking a data miss on every
userspace instruction miss") has shown that limiting the read of
faulting instruction to likely cases improves performance.

This patch goes further into this direction by limiting the read
of the faulting instruction to the only cases where it is likely
needed.

On an MPC885, with the same benchmark app as in the commit referred
above, we see a reduction of about 3900 dTLB misses (approx 3%):

Before the patch:
 Performance counter stats for './fault 500' (10 runs):

         683033312      cpu-cycles                                                    ( +-  0.03% )
            134538      dTLB-load-misses                                              ( +-  0.03% )
             46099      iTLB-load-misses                                              ( +-  0.02% )
             19681      faults                                                        ( +-  0.02% )

       5.389747878 seconds time elapsed                                          ( +-  0.06% )

With the patch:

 Performance counter stats for './fault 500' (10 runs):

         682112862      cpu-cycles                                                    ( +-  0.03% )
            130619      dTLB-load-misses                                              ( +-  0.03% )
             46073      iTLB-load-misses                                              ( +-  0.05% )
             19681      faults                                                        ( +-  0.01% )

       5.381342641 seconds time elapsed                                          ( +-  0.07% )

The proper work of the huge stack expansion was tested with the
following app:

int main(int argc, char **argv)
{
	char buf[1024 * 1025];

	sprintf(buf, "Hello world !\n");
	printf(buf);

	exit(0);
}

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add include of pagemap.h to fix build errors]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-25 00:08:25 +10:00
Christophe Leroy 8a0b1120cb powerpc/mm: Use instruction symbolic names in store_updates_sp()
Use symbolic names defined in asm/ppc-opcode.h
instead of hardcoded values.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-25 00:08:24 +10:00
Simon Guo eacbb218fb powerpc: Export tm_enable()/tm_disable/tm_abort() APIs
This patch exports tm_enable()/tm_disable/tm_abort() APIs, which
will be used for PR KVM transactional memory logic.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-24 16:04:02 +10:00
Nicholas Piggin 0078778a86 powerpc/mm/radix: implement LPID based TLB flushes to be used by KVM
Implement a local TLB flush for invalidating an LPID with variants for
process or partition scope. And a global TLB flush for invalidating
a partition scoped page of an LPID.

These will be used by KVM in subsequent patches.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-17 11:13:29 +10:00
Aneesh Kumar K.V 738f964555 powerpc/mm: Use page fragments for allocation page table at PMD level
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:29:12 +10:00
Aneesh Kumar K.V 8a6c697b99 powerpc/mm: Implement helpers for pagetable fragment support at PMD level
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:29:12 +10:00
Aneesh Kumar K.V 0c4d268029 powerpc/book3s64/mm: Simplify the rcu callback for page table free
Instead of encoding shift in the table address, use an enumerated index value.
This allow us to do different things in the callback for pte and pmd.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:29:11 +10:00
Aneesh Kumar K.V 1c7ec8a40a powerpc/mm/book3s64/4k: Switch 4k pagesize config to use pagetable fragment
4K config use one full page at level 4 of the pagetable. Add support for single
fragment allocation in pagetable fragment code and and use that for 4K config.
This makes both 4k and 64k use the same code path. Later we will switch pmd to
use the page table fragment code. This is done only for 64bit platforms which
is using page table fragment support.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:29:11 +10:00
Aneesh Kumar K.V 702346768c powerpc/mm/nohash: Remove pte fragment dependency from nohash
Now that we have removed 64K page size support, the RCU page table free can
be much simpler for nohash. Make a copy of the the rcu callback to pgalloc.h
header similar to nohash 32. We could possibly merge 32 and 64 bit there. But
that is for a later patch

We also move the book3s specific handler to pgtable_book3s64.c. This will be
updated in a later patch to handle split pmd ptlock.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:29:11 +10:00
Aneesh Kumar K.V 8ce74cffff powerpc/mm: Rename pte fragment functions
We rename the alloc and get_from_cache to indicate they operate on pte
fragments. In later patch we will add pmd fragment support.

No functional change in this patch.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:29:10 +10:00
Aneesh Kumar K.V af60a4cf87 powerpc/mm: Use pmd_lockptr instead of opencoding it
In later patch we switch pmd_lock from mm->page_table_lock to split pmd ptlock.
It avoid compilations issues, use pmd_lockptr helper.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:29:09 +10:00
Aneesh Kumar K.V 59879d542a powerpc/mm/book3s64: Move book3s64 code to pgtable-book3s64
Only code movement and avoid #ifdef.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15 22:29:09 +10:00
Al Viro 3691d61455 powerpc/syscalls: Switch trivial cases to SYSCALL_DEFINE
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-10 23:25:12 +10:00
Hari Bathini 8597538712 powerpc/fadump: Do not use hugepages when fadump is active
FADump capture kernel boots in restricted memory environment preserving
the context of previous kernel to save vmcore. Supporting hugepages in
such environment makes things unnecessarily complicated, as hugepages
need memory set aside for them. This means most of the capture kernel's
memory is used in supporting hugepages. In most cases, this results in
out-of-memory issues while booting FADump capture kernel. But hugepages
are not of much use in capture kernel whose only job is to save vmcore.
So, disabling hugepages support, when fadump is active, is a reliable
solution for the out of memory issues. Introducing a flag variable to
disable HugeTLB support when fadump is active.

Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03 23:09:25 +10:00
Eric W. Biederman 3eb0f5193b signal: Ensure every siginfo we send has all bits initialized
Call clear_siginfo to ensure every stack allocated siginfo is properly
initialized before being passed to the signal sending functions.

Note: It is not safe to depend on C initializers to initialize struct
siginfo on the stack because C is allowed to skip holes when
initializing a structure.

The initialization of struct siginfo in tracehook_report_syscall_exit
was moved from the helper user_single_step_siginfo into
tracehook_report_syscall_exit itself, to make it clear that the local
variable siginfo gets fully initialized.

In a few cases the scope of struct siginfo has been reduced to make it
clear that siginfo siginfo is not used on other paths in the function
in which it is declared.

Instances of using memset to initialize siginfo have been replaced
with calls clear_siginfo for clarity.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:40:51 -05:00
Balbir Singh fb5924fddf powerpc/mm: Flush cache on memory hot(un)plug
This patch adds support for flushing potentially dirty cache lines
when memory is hot-plugged/hot-un-plugged. The support is currently
limited to 64 bit systems.

The bug was exposed when mappings for a device were actually
hot-unplugged and plugged in back later. A similar issue was observed
during the development of memtrace, but memtrace does it's own
flushing of region via a custom routine.

These patches do a flush both on hotplug/unplug to clear any stale
data in the cache w.r.t mappings, there is a small race window where a
clean cache line may be created again just prior to tearing down the
mapping.

The patches were tested by disabling the flush routines in memtrace
and doing I/O on the trace file. The system immediately
checkstops (quite reliablly if prior to the hot-unplug of the memtrace
region, we memset the regions we are about to hot unplug). After these
patches no custom flushing is needed in the memtrace code.

Fixes: 9d5171a8f2 ("powerpc/powernv: Enable removal of memory for in memory tracing")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Reza Arbab <arbab@linux.ibm.com>
Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-24 09:46:56 +10:00
Linus Torvalds b1cb4f93b5 powerpc fixes for 4.17 #2
- Fix crashes when loading modules built with a different CONFIG_RELOCATABLE
    value by adding CONFIG_RELOCATABLE to vermagic.
 
  - Fix busy loops in the OPAL NVRAM driver if we get certain error conditions
    from firmware.
 
  - Remove tlbie trace points from KVM code that's called in real mode, because
    it causes crashes.
 
  - Fix checkstops caused by invalid tlbiel on Power9 Radix.
 
  - Ensure the set of CPU features we "know" are always enabled is actually the
    minimal set when we build with support for firmware supplied CPU features.
 
 Thanks to:
   Aneesh Kumar K.V, Anshuman Khandual, Nicholas Piggin.
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Merge tag 'powerpc-4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - Fix crashes when loading modules built with a different
   CONFIG_RELOCATABLE value by adding CONFIG_RELOCATABLE to vermagic.

 - Fix busy loops in the OPAL NVRAM driver if we get certain error
   conditions from firmware.

 - Remove tlbie trace points from KVM code that's called in real mode,
   because it causes crashes.

 - Fix checkstops caused by invalid tlbiel on Power9 Radix.

 - Ensure the set of CPU features we "know" are always enabled is
   actually the minimal set when we build with support for firmware
   supplied CPU features.

Thanks to: Aneesh Kumar K.V, Anshuman Khandual, Nicholas Piggin.

* tag 'powerpc-4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Fix CPU_FTRS_ALWAYS vs DT CPU features
  powerpc/mm/radix: Fix checkstops caused by invalid tlbiel
  KVM: PPC: Book3S HV: trace_tlbie must not be called in realmode
  powerpc/8xx: Fix build with hugetlbfs enabled
  powerpc/powernv: Fix OPAL NVRAM driver OPAL_BUSY loops
  powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops
  powerpc/fscr: Enable interrupts earlier before calling get_user()
  powerpc/64s: Fix section mismatch warnings from setup_rfi_flush()
  powerpc/modules: Fix crashes by adding CONFIG_RELOCATABLE to vermagic
2018-04-15 11:57:12 -07:00
Michael Ellerman 2675c13b29 powerpc/mm/radix: Fix checkstops caused by invalid tlbiel
In tlbiel_radix_set_isa300() we use the PPC_TLBIEL() macro to
construct tlbiel instructions. The instruction takes 5 fields, two of
which are registers, and the others are constants. But because it's
constructed with inline asm the compiler doesn't know that.

We got the constraint wrong on the 'r' field, using "r" tells the
compiler to put the value in a register. The value we then get in the
macro is the *register number*, not the value of the field.

That means when we mask the register number with 0x1 we get 0 or 1
depending on which register the compiler happens to put the constant
in, eg:

  li      r10,1
  tlbiel  r8,r9,2,0,0

  li      r7,1
  tlbiel  r10,r6,0,0,1

If we're unlucky we might generate an invalid instruction form, for
example RIC=0, PRS=1 and R=0, tlbiel r8,r7,0,1,0, this has been
observed to cause machine checks:

  Oops: Machine check, sig: 7 [#1]
  CPU: 24 PID: 0 Comm: swapper
  NIP:  00000000000385f4 LR: 000000000100ed00 CTR: 000000000000007f
  REGS: c00000000110bb40 TRAP: 0200
  MSR:  9000000000201003 <SF,HV,ME,RI,LE>  CR: 48002222  XER: 20040000
  CFAR: 00000000000385d0 DAR: 0000000000001c00 DSISR: 00000200 SOFTE: 1

If the machine check happens early in boot while we have MSR_ME=0 it
will escalate into a checkstop and kill the box entirely.

To fix it we could change the inline asm constraint to "i" which
tells the compiler the value is a constant. But a better fix is to just
pass a literal 1 into the macro, which bypasses any problems with inline
asm constraints.

Fixes: d4748276ae ("powerpc/64s: Improve local TLB flush for boot and MCE on POWER9")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
2018-04-12 23:49:55 +10:00
Kees Cook 8f2af155b5 exec: pass stack rlimit into mm layout functions
Patch series "exec: Pin stack limit during exec".

Attempts to solve problems with the stack limit changing during exec
continue to be frustrated[1][2].  In addition to the specific issues
around the Stack Clash family of flaws, Andy Lutomirski pointed out[3]
other places during exec where the stack limit is used and is assumed to
be unchanging.  Given the many places it gets used and the fact that it
can be manipulated/raced via setrlimit() and prlimit(), I think the only
way to handle this is to move away from the "current" view of the stack
limit and instead attach it to the bprm, and plumb this down into the
functions that need to know the stack limits.  This series implements
the approach.

[1] 04e35f4495 ("exec: avoid RLIMIT_STACK races with prlimit()")
[2] 779f4e1c6c ("Revert "exec: avoid RLIMIT_STACK races with prlimit()"")
[3] to security@kernel.org, "Subject: existing rlimit races?"

This patch (of 3):

Since it is possible that the stack rlimit can change externally during
exec (either via another thread calling setrlimit() or another process
calling prlimit()), provide a way to pass the rlimit down into the
per-architecture mm layout functions so that the rlimit can stay in the
bprm structure instead of sitting in the signal structure until exec is
finalized.

Link: http://lkml.kernel.org/r/1518638796-20819-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Greg KH <greg@kroah.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Cc: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:37 -07:00
Michal Hocko 666feb21a0 mm, migrate: remove reason argument from new_page_t
No allocation callback is using this argument anymore.  new_page_node
used to use this parameter to convey node_id resp.  migration error up
to move_pages code (do_move_page_to_node_array).  The error status never
made it into the final status field and we have a better way to
communicate node id to the status field now.  All other allocation
callbacks simply ignored the argument so we can drop it finally.

[mhocko@suse.com: fix migration callback]
  Link: http://lkml.kernel.org/r/20180105085259.GH2801@dhcp22.suse.cz
[akpm@linux-foundation.org: fix alloc_misplaced_dst_page()]
[mhocko@kernel.org: fix build]
  Link: http://lkml.kernel.org/r/20180103091134.GB11319@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20180103082555.14592-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Andrea Reale <ar@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:32 -07:00
Aneesh Kumar K.V 032900e62c powerpc/8xx: Fix build with hugetlbfs enabled
8xx uses the slice code when hugetlbfs is enabled. We missed a header
include on 8xx which resulted in the below build failure:

  config: mpc885_ads_defconfig + CONFIG_HUGETLBFS

  arch/powerpc/mm/slice.c: In function 'slice_get_unmapped_area':
  arch/powerpc/mm/slice.c:655:2: error: implicit declaration of function 'need_extra_context'
  arch/powerpc/mm/slice.c:656:3: error: implicit declaration of function 'alloc_extended_context'

on PPC64 the mmu_context.h was included via linux/pkeys.h

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-11 12:00:23 +10:00
Linus Torvalds 49a695ba72 powerpc updates for 4.17
Notable changes:
 
  - Support for 4PB user address space on 64-bit, opt-in via mmap().
 
  - Removal of POWER4 support, which was accidentally broken in 2016 and no one
    noticed, and blocked use of some modern instructions.
 
  - Workarounds so that the hypervisor can enable Transactional Memory on Power9.
 
  - A series to disable the DAWR (Data Address Watchpoint Register) on Power9.
 
  - More information displayed in the meltdown/spectre_v1/v2 sysfs files.
 
  - A vpermxor (Power8 Altivec) implementation for the raid6 Q Syndrome.
 
  - A big series to make the allocation of our pacas (per cpu area), kernel page
    tables, and per-cpu stacks NUMA aware when using the Radix MMU on Power9.
 
 And as usual many fixes, reworks and cleanups.
 
 Thanks to:
   Aaro Koskinen, Alexandre Belloni, Alexey Kardashevskiy, Alistair Popple, Andy
   Shevchenko, Aneesh Kumar K.V, Anshuman Khandual, Balbir Singh, Benjamin
   Herrenschmidt, Christophe Leroy, Christophe Lombard, Cyril Bur, Daniel Axtens,
   Dave Young, Finn Thain, Frederic Barrat, Gustavo Romero, Horia Geantă,
   Jonathan Neuschäfer, Kees Cook, Larry Finger, Laurent Dufour, Laurent Vivier,
   Logan Gunthorpe, Madhavan Srinivasan, Mark Greer, Mark Hairgrove, Markus
   Elfring, Mathieu Malaterre, Matt Brown, Matt Evans, Mauricio Faria de
   Oliveira, Michael Neuling, Naveen N. Rao, Nicholas Piggin, Paul Mackerras,
   Philippe Bergheaud, Ram Pai, Rob Herring, Sam Bobroff, Segher Boessenkool,
   Simon Guo, Simon Horman, Stewart Smith, Sukadev Bhattiprolu, Suraj Jitindar
   Singh, Thiago Jung Bauermann, Vaibhav Jain, Vaidyanathan Srinivasan, Vasant
   Hegde, Wei Yongjun.
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Merge tag 'powerpc-4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Support for 4PB user address space on 64-bit, opt-in via mmap().

   - Removal of POWER4 support, which was accidentally broken in 2016
     and no one noticed, and blocked use of some modern instructions.

   - Workarounds so that the hypervisor can enable Transactional Memory
     on Power9.

   - A series to disable the DAWR (Data Address Watchpoint Register) on
     Power9.

   - More information displayed in the meltdown/spectre_v1/v2 sysfs
     files.

   - A vpermxor (Power8 Altivec) implementation for the raid6 Q
     Syndrome.

   - A big series to make the allocation of our pacas (per cpu area),
     kernel page tables, and per-cpu stacks NUMA aware when using the
     Radix MMU on Power9.

  And as usual many fixes, reworks and cleanups.

  Thanks to: Aaro Koskinen, Alexandre Belloni, Alexey Kardashevskiy,
  Alistair Popple, Andy Shevchenko, Aneesh Kumar K.V, Anshuman Khandual,
  Balbir Singh, Benjamin Herrenschmidt, Christophe Leroy, Christophe
  Lombard, Cyril Bur, Daniel Axtens, Dave Young, Finn Thain, Frederic
  Barrat, Gustavo Romero, Horia Geantă, Jonathan Neuschäfer, Kees Cook,
  Larry Finger, Laurent Dufour, Laurent Vivier, Logan Gunthorpe,
  Madhavan Srinivasan, Mark Greer, Mark Hairgrove, Markus Elfring,
  Mathieu Malaterre, Matt Brown, Matt Evans, Mauricio Faria de Oliveira,
  Michael Neuling, Naveen N. Rao, Nicholas Piggin, Paul Mackerras,
  Philippe Bergheaud, Ram Pai, Rob Herring, Sam Bobroff, Segher
  Boessenkool, Simon Guo, Simon Horman, Stewart Smith, Sukadev
  Bhattiprolu, Suraj Jitindar Singh, Thiago Jung Bauermann, Vaibhav
  Jain, Vaidyanathan Srinivasan, Vasant Hegde, Wei Yongjun"

* tag 'powerpc-4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (207 commits)
  powerpc/64s/idle: Fix restore of AMOR on POWER9 after deep sleep
  powerpc/64s: Fix POWER9 DD2.2 and above in cputable features
  powerpc/64s: Fix pkey support in dt_cpu_ftrs, add CPU_FTR_PKEY bit
  powerpc/64s: Fix dt_cpu_ftrs to have restore_cpu clear unwanted LPCR bits
  Revert "powerpc/64s/idle: POWER9 ESL=0 stop avoid save/restore overhead"
  powerpc: iomap.c: introduce io{read|write}64_{lo_hi|hi_lo}
  powerpc: io.h: move iomap.h include so that it can use readq/writeq defs
  cxl: Fix possible deadlock when processing page faults from cxllib
  powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it
  powerpc/mm/radix: Update command line parsing for disable_radix
  powerpc/mm/radix: Parse disable_radix commandline correctly.
  powerpc/mm/hugetlb: initialize the pagetable cache correctly for hugetlb
  powerpc/mm/radix: Update pte fragment count from 16 to 256 on radix
  powerpc/mm/keys: Update documentation and remove unnecessary check
  powerpc/64s/idle: POWER9 ESL=0 stop avoid save/restore overhead
  powerpc/64s/idle: Consolidate power9_offline_stop()/power9_idle_stop()
  powerpc/powernv: Always stop secondaries before reboot/shutdown
  powerpc: hard disable irqs in smp_send_stop loop
  powerpc: use NMI IPI for smp_send_stop
  powerpc/powernv: Fix SMT4 forcing idle code
  ...
2018-04-07 12:08:19 -07:00
Dan Williams 09135cc594 mm, powerpc: use vma_kernel_pagesize() in vma_mmu_pagesize()
Patch series "mm, smaps: MMUPageSize for device-dax", v3.

Similar to commit 31383c6865 ("mm, hugetlbfs: introduce ->split() to
vm_operations_struct") here is another occasion where we want
special-case hugetlbfs/hstate enabling to also apply to device-dax.

This prompts the question what other hstate conversions we might do
beyond ->split() and ->pagesize(), but this appears to be the last of
the usages of hstate_vma() in generic/non-hugetlbfs specific code paths.

This patch (of 3):

The current powerpc definition of vma_mmu_pagesize() open codes looking
up the page size via hstate.  It is identical to the generic
vma_kernel_pagesize() implementation.

Now, vma_kernel_pagesize() is growing support for determining the page
size of Device-DAX vmas in addition to the existing Hugetlbfs page size
determination.

Ideally, if the powerpc vma_mmu_pagesize() used vma_kernel_pagesize() it
would automatically benefit from any new vma-type support that is added
to vma_kernel_pagesize().  However, the powerpc vma_mmu_pagesize() is
prevented from calling vma_kernel_pagesize() due to a circular header
dependency that requires vma_mmu_pagesize() to be defined before
including <linux/hugetlb.h>.

Break this circular dependency by defining the default vma_mmu_pagesize()
as a __weak symbol to be overridden by the powerpc version.

Link: http://lkml.kernel.org/r/151996254179.27922.2213728278535578744.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Jane Chu <jane.chu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-05 21:36:26 -07:00
Anshuman Khandual 310253514b mm/migrate: rename migration reason MR_CMA to MR_CONTIG_RANGE
alloc_contig_range() initiates compaction and eventual migration for the
purpose of either CMA or HugeTLB allocations.  At present, the reason
code remains the same MR_CMA for either of these cases.  Let's make it
MR_CONTIG_RANGE which will appropriately reflect the reason code in both
these cases.

Link: http://lkml.kernel.org/r/20180202091518.18798-1-khandual@linux.vnet.ibm.com
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-05 21:36:24 -07:00
Aneesh Kumar K.V cec4e9b28f powerpc/mm/radix: Parse disable_radix commandline correctly.
kernel parameter disable_radix takes different options
disable_radix=yes|no|1|0 or just disable_radix. When using the later
format we get below error.

 `Malformed early option 'disable_radix'`

Fixes: 1fd6c02207 ("powerpc/mm: Add a CONFIG option to choose if radix is used by default")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-04 16:59:36 +10:00
Aneesh Kumar K.V 6fa504835d powerpc/mm/hugetlb: initialize the pagetable cache correctly for hugetlb
With 64k page size, we have hugetlb pte entries at the pmd and pud level for
book3s64. We don't need to create a separate page table cache for that. With 4k
we need to make sure hugepd page table cache for 16M is placed at PUD level
and 16G at the PGD level.

Simplify all these by not using HUGEPD_PD_SHIFT which is confusing for book3s64.

Without this patch, with 64k page size we create pagetable caches with shift
value 10 and 7 which are not used at all.

Fixes: 419df06eea ("powerpc: Reduce the PTE_INDEX_SIZE")

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-04 16:58:53 +10:00
Aneesh Kumar K.V fb4e5dbd44 powerpc/mm/radix: Update pte fragment count from 16 to 256 on radix
With split PTL (page table lock) config, we allocate the level
4 (leaf) page table using pte fragment framework instead of slab cache
like other levels. This was done to enable us to have split page table
lock at the level 4 of the page table. We use page->plt backing the
all the level 4 pte fragment for the lock.

Currently with Radix, we use only 16 fragments out of the allocated
page. In radix each fragment is 256 bytes which means we use only 4k
out of the allocated 64K page wasting 60k of the allocated memory.
This was done earlier to keep it closer to hash.

This patch update the pte fragment count to 256, thereby using the
full 64K page and reducing the memory usage. Performance tests shows
really low impact even with THP disabled. With THP disabled we will be
contenting further less on level 4 ptl and hence the impact should be
further low.

  256 threads:
    without patch (10 runs of ./ebizzy  -m -n 1000 -s 131072 -S 100)
      median = 15678.5
      stdev = 42.1209

    with patch:
      median = 15354
      stdev = 194.743

This is with THP disabled. With THP enabled the impact of the patch
will be less.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-04 16:58:06 +10:00
Aneesh Kumar K.V f2ed480fa4 powerpc/mm/keys: Update documentation and remove unnecessary check
Adds more code comments. We also remove an unnecessary pkey check
after we check for pkey error in this patch.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-04 15:23:09 +10:00
Mathieu Malaterre 19e68b2aec powerpc/mm/radix: Fix always false comparison against MMU_NO_CONTEXT
In commit 9690c15742 ("powerpc/mm/radix: Fix always false comparison
against MMU_NO_CONTEXT") an issue was discovered where `mm->context.id` was
being truncated to an `unsigned int`, while the PID is actually an
`unsigned long`. Update the earlier patch by fixing one remaining
occurrence. Discovered during a compilation with W=1:

  arch/powerpc/mm/tlb-radix.c:702:19: error: comparison is always false due to limited range of data type [-Werror=type-limits]

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-01 22:15:34 +10:00
Nicholas Piggin 471d7ff8b5 powerpc/64s: Remove POWER4 support
POWER4 has been broken since at least the change 49d09bf2a6
("powerpc/64s: Optimise MSR handling in exception handling"), which
requires mtmsrd L=1 support. This was introduced in ISA v2.01, and
POWER4 supports ISA v2.00.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-01 00:47:50 +11:00
Jonathan Neuschäfer 7e1405917c powerpc/mm/32: Remove the reserved memory hack
This hack, introduced in commit c5df7f7751 ("powerpc: allow ioremap
within reserved memory regions") is now unnecessary.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-01 00:47:44 +11:00
Jonathan Neuschäfer 2bbf63264a powerpc/mm/32: Use page_is_ram to check for RAM
On systems where there is MMIO space between different blocks of RAM in
the physical address space, __ioremap_caller did not allow mapping these
MMIO areas, because they were below the end RAM and thus considered RAM
as well.  Use the memblock-based page_is_ram function, which returns
false for such MMIO holes.

v2:
  Keep the check for p < virt_to_phys(high_memory). On 32-bit systems
  with high memory (memory above physical address 4GiB), the high memory
  is expected to be available though ioremap. The high_memory variable
  marks the end of low memory; comparing against it means that only
  ioremap requests for low RAM will be denied.
  Reported by Michael Ellerman.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-01 00:47:43 +11:00
Jonathan Neuschäfer f65e67c7e3 powerpc/mm: Use memblock API for PPC32 page_is_ram
To support accurate checking for different blocks of memory on PPC32,
use the same memblock-based approach that's already used on PPC64 also
on PPC32.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-01 00:47:42 +11:00
Jonathan Neuschäfer 2615c93e5f powerpc/mm: Simplify page_is_ram by using memblock_is_memory
Instead of open-coding the search in page_is_ram, call memblock_is_memory.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-01 00:47:42 +11:00
Michael Ellerman f437c51748 Merge branch 'topic/paca' into next
Bring in yet another series that touches KVM code, and might need to
be merged into the kvm-ppc branch to resolve conflicts.

This required some changes in pnv_power9_force_smt4_catch/release()
due to the paca array becomming an array of pointers.
2018-03-31 09:09:36 +11:00
Aneesh Kumar K.V c2b4d8b741 powerpc/mm/hash64: Increase the VA range
This patch increases the max virtual (effective) address value to 4PB.
With 4K page size config we continue to limit ourself to 64TB.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Keep the H_PGTABLE_RANGE test, update it to work]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-31 00:10:38 +11:00
Aneesh Kumar K.V f384796c40 powerpc/mm: Add support for handling > 512TB address in SLB miss
For addresses above 512TB we allocate additional mmu contexts. To make
it all easy, addresses above 512TB are handled with IR/DR=1 and with
stack frame setup.

The mmu_context_t is also updated to track the new extended_ids. To
support upto 4PB we need a total 8 contexts.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Minor formatting tweaks and comment wording, switch BUG to WARN
      in get_ea_context().]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-31 00:10:38 +11:00
Aneesh Kumar K.V 0dea04b288 powerpc/mm/slice: Consolidate return path in slice_get_unmapped_area()
In a following patch, on finding a free area we will need to do
allocatinon of extra contexts as needed. Consolidating the return path
for slice_get_unmapped_area() will make that easier.

Split into a separate patch to make review easy.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-31 00:10:37 +11:00
Ram Pai f208638680 powerpc/mm: Fix thread_pkey_regs_init()
thread_pkey_regs_init() initializes the pkey related registers
instead of initializing the fields in the task structures.  Fortunately
those key related registers are re-set to zero when the task
gets scheduled on the cpu. However its good to fix this glaringly
visible error.

Fixes: 06bb53b338 ("powerpc: store and restore the pkey state across context switches")
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-31 00:10:33 +11:00
Nicholas Piggin 29ab6c4708 powerpc/mm: Pass node id into create_section_mapping
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Move __map_kernel_page_nid() inside #ifdef SPARSEMEM_VMEMMAP]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-31 00:07:10 +11:00
Nicholas Piggin 2ad452ffaa powerpc/64s/radix: Allocate kernel page tables node-local if possible
Try to allocate kernel page tables for direct mapping and vmemmap
according to the node of the memory they will map. The node is not
available for the linear map in early boot, so use range allocation
to allocate the page tables from the region they map, which is
effectively node-local.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fix build error in radix__create_section_mapping()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-31 00:07:09 +11:00
Nicholas Piggin 0633dafcf8 powerpc/64s/radix: Split early page table mapping to its own function
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-31 00:07:09 +11:00
Nicholas Piggin 9bd9be006c powerpc/mm/numa: move numa topology discovery earlier
Split sparsemem initialisation from basic numa topology discovery.
Move the parsing earlier in boot, before pacas are allocated.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-30 23:34:26 +11:00
Nicholas Piggin 499dcd4137 powerpc/64s: Allocate LPPACAs individually
We no longer allocate lppacas in an array, so this patch removes the
1kB static alignment for the structure, and enforces the PAPR
alignment requirements at allocation time. We can not reduce the 1kB
allocation size however, due to existing KVM hypervisors.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-30 23:34:24 +11:00
Nicholas Piggin d2e60075a3 powerpc/64: Use array of paca pointers and allocate pacas individually
Change the paca array into an array of pointers to pacas. Allocate
pacas individually.

This allows flexibility in where the PACAs are allocated. Future work
will allocate them node-local. Platforms that don't have address limits
on PACAs would be able to defer PACA allocations until later in boot
rather than allocate all possible ones up-front then freeing unused.

This is slightly more overhead (one additional indirection) for cross
CPU paca references, but those aren't too common.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-30 23:34:23 +11:00
Michael Ellerman 95dff480bb Merge branch 'fixes' into next
Merge our fixes branch from the 4.16 cycle.

There were a number of important fixes merged, in particular some Power9
workarounds that we want in next for testing purposes. There's also been
some conflicting changes in the CPU features code which are best merged
and tested before going upstream.
2018-03-28 22:59:50 +11:00
Alexey Kardashevskiy b574df9488 powerpc/mm: Fix typo in comments
Fixes: 912cc87a6 "powerpc/mm/radix: Add LPID based tlb flush helpers"
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27 23:44:56 +11:00
Mauricio Faria de Oliveira bde709a708 powerpc/mm: Fix section mismatch warning in stop_machine_change_mapping()
Fix the warning messages for stop_machine_change_mapping(), and a number
of other affected functions in its call chain.

All modified functions are under CONFIG_MEMORY_HOTPLUG, so __meminit
is okay (keeps them / does not discard them).

Boot-tested on powernv/power9/radix-mmu and pseries/power8/hash-mmu.

    $ make -j$(nproc) CONFIG_DEBUG_SECTION_MISMATCH=y vmlinux
    ...
      MODPOST vmlinux.o
    WARNING: vmlinux.o(.text+0x6b130): Section mismatch in reference from the function stop_machine_change_mapping() to the function .meminit.text:create_physical_mapping()
    The function stop_machine_change_mapping() references
    the function __meminit create_physical_mapping().
    This is often because stop_machine_change_mapping lacks a __meminit
    annotation or the annotation of create_physical_mapping is wrong.

    WARNING: vmlinux.o(.text+0x6b13c): Section mismatch in reference from the function stop_machine_change_mapping() to the function .meminit.text:create_physical_mapping()
    The function stop_machine_change_mapping() references
    the function __meminit create_physical_mapping().
    This is often because stop_machine_change_mapping lacks a __meminit
    annotation or the annotation of create_physical_mapping is wrong.
    ...

Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27 23:44:55 +11:00
Paul Mackerras dbfcf3cb9c powerpc/64: Call H_REGISTER_PROC_TBL when running as a HPT guest on POWER9
On POWER9, since commit cc3d294013 ("powerpc/64: Enable use of radix
MMU under hypervisor on POWER9", 2017-01-30), we set both the radix and
HPT bits in the client-architecture-support (CAS) vector, which tells
the hypervisor that we can do either radix or HPT.  According to PAPR,
if we use this combination we are promising to do a H_REGISTER_PROC_TBL
hcall later on to let the hypervisor know whether we are doing radix
or HPT.  We currently do this call if we are doing radix but not if
we are doing HPT.  If the hypervisor is able to support both radix
and HPT guests, it would be entitled to defer allocation of the HPT
until the H_REGISTER_PROC_TBL call, and to fail any attempts to create
HPTEs until the H_REGISTER_PROC_TBL call.  Thus we need to do a
H_REGISTER_PROC_TBL call when we are doing HPT; otherwise we may
crash at boot time.

This adds the code to call H_REGISTER_PROC_TBL in this case, before
we attempt to create any HPT entries using H_ENTER.

Fixes: cc3d294013 ("powerpc/64: Enable use of radix MMU under hypervisor on POWER9")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27 19:25:08 +11:00
Aneesh Kumar K.V a5d4b5891c powerpc/mm: Fixup tlbie vs store ordering issue on POWER9
On POWER9, under some circumstances, a broadcast TLB invalidation
might complete before all previous stores have drained, potentially
allowing stale stores from becoming visible after the invalidation.
This works around it by doubling up those TLB invalidations which was
verified by HW to be sufficient to close the risk window.

This will be documented in a yet-to-be-published errata.

Fixes: 1a472c9dba ("powerpc/mm/radix: Add tlbflush routines")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Enable the feature in the DT CPU features code for all Power9,
      rename the feature to CPU_FTR_P9_TLBIE_BUG per benh.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23 20:48:03 +11:00
Aneesh Kumar K.V 243fee3249 powerpc/mm/radix: Move the functions that does the actual tlbie closer
No functionality change. Just code movement to ease code changes later

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23 16:17:42 +11:00
Aneesh Kumar K.V 99491e2d0e powerpc/mm/radix: Remove unused code
These function are not used in the code. Remove them.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23 16:17:39 +11:00
Benjamin Herrenschmidt 80a4ae202f powerpc/mm: Workaround Nest MMU bug with TLB invalidations
On POWER9 the Nest MMU may fail to invalidate some translations when
doing a tlbie "by PID" or "by LPID" that is targeted at the TLB only
and not the page walk cache.

This works around it by forcing such invalidations to escalate to
RIC=2 (full invalidation of TLB *and* PWC) when a coprocessor is in
use for the context.

Fixes: 03b8abedf4 ("cxl: Enable global TLBIs for cxl contexts")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[balbirs: fixed spelling and coding style to quiesce checkpatch.pl]
Tested-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23 14:16:58 +11:00
Benjamin Herrenschmidt aff6f8cb3e powerpc/mm: Add tracking of the number of coprocessors using a context
Currently, when using coprocessors (which use the Nest MMU), we
simply increment the active_cpu count to force all TLB invalidations
to be come broadcast.

Unfortunately, due to an errata in POWER9, we will need to know
more specifically that coprocessors are in use.

This maintains a separate copros counter in the MMU context for
that purpose.

NB. The commit mentioned in the fixes tag below is not at fault for
the bug we're fixing in this commit and the next, but this fix applies
on top the infrastructure it introduced.

Fixes: 03b8abedf4 ("cxl: Enable global TLBIs for cxl contexts")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23 14:14:31 +11:00
Nicholas Piggin 014a32b30e powerpc/mm/slice: remove radix calls to the slice code
This is a tidy up which removes radix MMU calls into the slice
code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 23:43:08 +11:00
Nicholas Piggin d262bd5a73 powerpc/mm/slice: Use const pointers to cached slice masks where possible
The slice_mask cache was a basic conversion which copied the slice
mask into caller's structures, because that's how the original code
worked. In most cases the pointer can be used directly instead, saving
a copy and an on-stack structure.

On POWER8, this increases vfork+exec+exit performance by 0.3%
and reduces time to mmap+munmap a 64kB page by 2%.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 23:43:08 +11:00
Nicholas Piggin 7490755830 powerpc/mm/slice: remove dead code
This code is never compiled in, and it gets broken by the next
patch, so remove it.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 23:43:07 +11:00
Nicholas Piggin b8c9354914 powerpc/mm/slice: Switch to 3-operand slice bitops helpers
This converts the slice_mask bit operation helpers to be the usual
3-operand kind, which allows 2 inputs to set a different output
without an extra copy, which is used in the next patch.

Adds slice_copy_mask, which will be used in the next patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 23:43:07 +11:00
Nicholas Piggin ae3066bd1c powerpc/mm/slice: implement slice_check_range_fits
Rather than build slice masks from a range then use that to check for
fit in a candidate mask, implement slice_check_range_fits that checks
if a range fits in a mask directly.

This allows several structures to be removed from stacks, and also we
don't expect a huge range in a lot of these cases, so building and
comparing a full mask is going to be more expensive than testing just
one or two bits of the range.

On POWER8, this increases vfork+exec+exit performance by 0.3%
and reduces time to mmap+munmap a 64kB page by 5%.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 23:43:06 +11:00
Nicholas Piggin 5709f7cfd8 powerpc/mm/slice: implement a slice mask cache
Calculating the slice mask can become a signifcant overhead for
get_unmapped_area. This patch adds a struct slice_mask for
each page size in the mm_context, and keeps these in synch with
the slices psize arrays and slb_addr_limit.

On Book3S/64 this adds 288 bytes to the mm_context_t for the
slice mask caches.

On POWER8, this increases vfork+exec+exit performance by 9.9%
and reduces time to mmap+munmap a 64kB page by 28%.

Reduces time to mmap+munmap by about 10% on 8xx.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 23:43:06 +11:00
Nicholas Piggin 830fd2d45a powerpc/mm/slice: pass pointers to struct slice_mask where possible
Pass around const pointers to struct slice_mask where possible, rather
than copies of slice_mask, to reduce stack and call overhead.

checkstack.pl gives, before:
0x00000d1c slice_get_unmapped_area [slice.o]:		592
0x00001864 is_hugepage_only_range [slice.o]:		448
0x00000754 slice_find_area_topdown [slice.o]:		400
0x00000484 slice_find_area_bottomup.isra.1 [slice.o]:	272
0x000017b4 slice_set_range_psize [slice.o]:		224
0x00000a4c slice_find_area [slice.o]:			128
0x00000160 slice_check_fit [slice.o]:			112

after:
0x00000ad0 slice_get_unmapped_area [slice.o]:		448
0x00001464 is_hugepage_only_range [slice.o]:		288
0x000006c0 slice_find_area [slice.o]:			144
0x0000016c slice_check_fit [slice.o]:			128
0x00000528 slice_find_area_bottomup.isra.2 [slice.o]:	128
0x000013e4 slice_set_range_psize [slice.o]:		128

This increases vfork+exec+exit performance by 1.5%.

Reduces time to mmap+munmap a 64kB page by 17%.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 23:43:05 +11:00
Nicholas Piggin 5a807e04bd powerpc/mm/slice: tidy lpsizes and hpsizes update loops
Make these loops look the same, and change their form so the
important part is not wrapped over so many lines.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 23:43:05 +11:00
Nicholas Piggin 1753dd1830 powerpc/mm/slice: Simplify and optimise slice context initialisation
The slice state of an mm gets zeroed then initialised upon exec.
This is the only caller of slice_set_user_psize now, so that can be
removed and instead implement a faster and simplified approach that
requires no locking or checking existing state.

This speeds up vfork+exec+exit performance on POWER8 by 3%.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 23:43:05 +11:00
Mathieu Malaterre d15a261d87 powerpc/32: Make some functions static
These functions can all be static, make it so.

Signed-off-by: Mathieu Malaterre <malat@debian.org>
[mpe: Combine a patch of Mathieu's with some other static conversions]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 15:50:42 +11:00
Anshuman Khandual 3d4f5f5848 powerpc/mm: Drop the function native_register_proc_table()
This is left over from the segment table implementation and not getting
called from any where now. Hence just drop it.

Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13 15:50:27 +11:00
Christophe Leroy 15472423ce powerpc/mm/slice: Allow up to 64 low slices
While the implementation of the "slices" address space allows
a significant amount of high slices, it limits the number of
low slices to 16 due to the use of a single u64 low_slices_psize
element in struct mm_context_t

On the 8xx, the minimum slice size is the size of the area
covered by a single PMD entry, ie 4M in 4K pages mode and 64M in
16K pages mode. This means we could have at least 64 slices.

In order to override this limitation, this patch switches the
handling of low_slices_psize to char array as done already for
high_slices_psize.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-06 09:21:23 +11:00
Christophe Leroy aa0ab02ba9 powerpc/mm/slice: Fix hugepage allocation at hint address on 8xx
On the 8xx, the page size is set in the PMD entry and applies to
all pages of the page table pointed by the said PMD entry.

When an app has some regular pages allocated (e.g. see below) and tries
to mmap() a huge page at a hint address covered by the same PMD entry,
the kernel accepts the hint allthough the 8xx cannot handle different
page sizes in the same PMD entry.

10000000-10001000 r-xp 00000000 00:0f 2597 /root/malloc
10010000-10011000 rwxp 00000000 00:0f 2597 /root/malloc

mmap(0x10080000, 524288, PROT_READ|PROT_WRITE,
     MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0) = 0x10080000

This results the app remaining forever in do_page_fault()/hugetlb_fault()
and when interrupting that app, we get the following warning:

[162980.035629] WARNING: CPU: 0 PID: 2777 at arch/powerpc/mm/hugetlbpage.c:354 hugetlb_free_pgd_range+0xc8/0x1e4
[162980.035699] CPU: 0 PID: 2777 Comm: malloc Tainted: G W       4.14.6 #85
[162980.035744] task: c67e2c00 task.stack: c668e000
[162980.035783] NIP:  c000fe18 LR: c00e1eec CTR: c00f90c0
[162980.035830] REGS: c668fc20 TRAP: 0700   Tainted: G W        (4.14.6)
[162980.035854] MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 24044224 XER: 20000000
[162980.036003]
[162980.036003] GPR00: c00e1eec c668fcd0 c67e2c00 00000010 c6869410 10080000 00000000 77fb4000
[162980.036003] GPR08: ffff0001 0683c001 00000000 ffffff80 44028228 10018a34 00004008 418004fc
[162980.036003] GPR16: c668e000 00040100 c668e000 c06c0000 c668fe78 c668e000 c6835ba0 c668fd48
[162980.036003] GPR24: 00000000 73ffffff 74000000 00000001 77fb4000 100fffff 10100000 10100000
[162980.036743] NIP [c000fe18] hugetlb_free_pgd_range+0xc8/0x1e4
[162980.036839] LR [c00e1eec] free_pgtables+0x12c/0x150
[162980.036861] Call Trace:
[162980.036939] [c668fcd0] [c00f0774] unlink_anon_vmas+0x1c4/0x214 (unreliable)
[162980.037040] [c668fd10] [c00e1eec] free_pgtables+0x12c/0x150
[162980.037118] [c668fd40] [c00eabac] exit_mmap+0xe8/0x1b4
[162980.037210] [c668fda0] [c0019710] mmput.part.9+0x20/0xd8
[162980.037301] [c668fdb0] [c001ecb0] do_exit+0x1f0/0x93c
[162980.037386] [c668fe00] [c001f478] do_group_exit+0x40/0xcc
[162980.037479] [c668fe10] [c002a76c] get_signal+0x47c/0x614
[162980.037570] [c668fe70] [c0007840] do_signal+0x54/0x244
[162980.037654] [c668ff30] [c0007ae8] do_notify_resume+0x34/0x88
[162980.037744] [c668ff40] [c000dae8] do_user_signal+0x74/0xc4
[162980.037781] Instruction dump:
[162980.037821] 7fdff378 81370000 54a3463a 80890020 7d24182e 7c841a14 712a0004 4082ff94
[162980.038014] 2f890000 419e0010 712a0ff0 408200e0 <0fe00000> 54a9000a 7f984840 419d0094
[162980.038216] ---[ end trace c0ceeca8e7a5800a ]---
[162980.038754] BUG: non-zero nr_ptes on freeing mm: 1
[162985.363322] BUG: non-zero nr_ptes on freeing mm: -1

In order to fix this, this patch uses the address space "slices"
implemented for BOOK3S/64 and enhanced to support PPC32 by the
preceding patch.

This patch modifies the context.id on the 8xx to be in the range
[1:16] instead of [0:15] in order to identify context.id == 0 as
not initialised contexts as done on BOOK3S

This patch activates CONFIG_PPC_MM_SLICES when CONFIG_HUGETLB_PAGE is
selected for the 8xx

Alltough we could in theory have as many slices as PMD entries, the
current slices implementation limits the number of low slices to 16.
This limitation is not preventing us to fix the initial issue allthough
it is suboptimal. It will be cured in a subsequent patch.

Fixes: 4b91428699 ("powerpc/8xx: Implement support of hugepages")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-06 09:21:23 +11:00
Christophe Leroy db3a528db4 powerpc/mm/slice: Enhance for supporting PPC32
In preparation for the following patch which will fix an issue on
the 8xx by re-using the 'slices', this patch enhances the
'slices' implementation to support 32 bits CPUs.

On PPC32, the address space is limited to 4Gbytes, hence only the low
slices will be used.

The high slices use bitmaps. As bitmap functions are not prepared to
handle bitmaps of size 0, this patch ensures that bitmap functions
are called only when SLICE_NUM_HIGH is not nul.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-06 09:21:23 +11:00
Christophe Leroy 326691ad4f powerpc/mm/slice: Remove intermediate bitmap copy
bitmap_or() and bitmap_andnot() can work properly with dst identical
to src1 or src2. There is no need of an intermediate result bitmap
that is copied back to dst in a second step.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-06 09:21:22 +11:00
Bharata B Rao 2f7d03e051 powerpc/mm/drmem: Fix unexpected flag value in ibm,dynamic-memory-v2
Memory addtion and removal by count and indexed-count methods
temporarily mark the LMBs that are being added/removed by a special
flag value DRMEM_LMB_RESERVED. Accessing flags value directly at a few
places without proper accessor method is causing two unexpected
side-effects:

- DRMEM_LMB_RESERVED bit is becoming part of the flags word of
  drconf_cell_v2 entries in ibm,dynamic-memory-v2 DT property.
- This results in extra drconf_cell entries in ibm,dynamic-memory-v2.
  For example if 1G memory is added, it leads to one entry for 3 LMBs
  and 1 separate entry for the last LMB. All the 4 LMBs should be
  defined by one entry here.

Fix this by always accessing the flags by its accessor method
drmem_lmb_flags().

Fixes: 2b31e3aec1 ("powerpc/drmem: Add support for ibm, dynamic-memory-v2 property")
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-23 16:45:51 +11:00
Nathan Fontenot 2c10636a0b powerpc/pseries: Check for zero filled ibm,dynamic-memory property
Some versions of QEMU will produce an ibm,dynamic-reconfiguration-memory
node with a ibm,dynamic-memory property that is zero-filled. This
causes the drmem code to oops trying to parse this property.

The fix for this is to validate that the property does contain LMB
entries before trying to parse it and bail if the count is zero.

  Oops: Kernel access of bad area, sig: 11 [#1]
  DAR: 0000000000000010
  NIP read_drconf_v1_cell+0x54/0x9c
  LR  read_drconf_v1_cell+0x48/0x9c
  Call Trace:
    __param_initcall_debug+0x0/0x28 (unreliable)
    drmem_init+0x144/0x2f8
    do_one_initcall+0x64/0x1d0
    kernel_init_freeable+0x298/0x38c
    kernel_init+0x24/0x160
    ret_from_kernel_thread+0x5c/0xb4

The ibm,dynamic-reconfiguration-memory device tree property generated
that causes this:

  ibm,dynamic-reconfiguration-memory {
          ibm,lmb-size = <0x0 0x10000000>;
          ibm,memory-flags-mask = <0xff>;
          ibm,dynamic-memory = <0x0 0x0 0x0 0x0 0x0 0x0>;
          linux,phandle = <0x7e57eed8>;
          ibm,associativity-lookup-arrays = <0x1 0x4 0x0 0x0 0x0 0x0>;
          ibm,memory-preservation-time = <0x0>;
  };

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Tested-by: Daniel Black <daniel@linux.vnet.ibm.com>
[mpe: Trim oops report]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-16 21:34:14 +11:00
Aneesh Kumar K.V ff31e10546 powerpc/mm/hash64: Store the slot information at the right offset for hugetlb
The hugetlb pte entries are at the PMD and PUD level, so we can't use
PTRS_PER_PTE to find the second half of the page table. Use the right
offset for PUD/PMD to get to the second half of the table.

Fixes: bf9a95f9a6 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-13 22:37:48 +11:00
Aneesh Kumar K.V fae2211697 powerpc/mm: Fix crashes with 16G huge pages
To support memory keys, we moved the hash pte slot information to the
second half of the page table. This was ok with PTE entries at level
4 (PTE page) and level 3 (PMD). We already allocate larger page table
pages at those levels to accomodate extra details. For level 4 we
already have the extra space which was used to track 4k hash page
table entry details and at level 3 the extra space was allocated to
track the THP details.

With hugetlbfs PTE, we used this extra space at the PMD level to store
the slot details. But we also support hugetlbfs PTE at PUD level for
16GB pages and PUD level page didn't allocate extra space. This
resulted in memory corruption.

Fix this by allocating extra space at PUD level when HUGETLB is
enabled.

Fixes: bf9a95f9a6 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-13 22:37:47 +11:00
Alexey Kardashevskiy 62e984ddfd powerpc/mm: Flush radix process translations when setting MMU type
Radix guests do normally invalidate process-scoped translations when a
new pid is allocated but migrated guests do not invalidate these so
migrated guests crash sometime, especially easy to reproduce with
migration happening within first 10 seconds after the guest boot start
on the same machine.

This adds the "Invalidate process-scoped translations" flush to fix
radix guests migration.

Fixes: 2ee13be34b ("KVM: PPC: Book3S HV: Update kvmppc_set_arch_compat() for ISA v3.00")
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Laurent Vivier <lvivier@redhat.com>
Tested-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-13 22:37:47 +11:00
Balbir Singh 4dd5f8a99e powerpc/mm/radix: Split linear mapping on hot-unplug
This patch splits the linear mapping if the hot-unplug range is
smaller than the mapping size. The code detects if the mapping needs
to be split into a smaller size and if so, uses the stop machine
infrastructure to clear the existing mapping and then remap the
remaining range using a smaller page size.

The code will skip any region of the mapping that overlaps with kernel
text and warn about it once. We don't want to remove a mapping where
the kernel text and the LMB we intend to remove overlap in the same
TLB mapping as it may affect the currently executing code.

I've tested these changes under a kvm guest with 2 vcpus, from a split
mapping point of view, some of the caveats mentioned above applied to
the testing I did.

Fixes: 4b5d62ca17 ("powerpc/mm: add radix__remove_section_mapping()")
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Tweak change log to match updated behaviour]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-08 23:56:11 +11:00
Nicholas Piggin eeb715c3e9 powerpc/64s/radix: Boot-time NULL pointer protection using a guard-PID
This change restores and formalises the behaviour that access to NULL
or other user addresses by the kernel during boot should fault rather
than succeed and modify memory. This was inadvertently broken when
fixing another bug, because it was previously not well defined and
only worked by chance.

powerpc/64s/radix uses high address bits to select an address space
"quadrant", which determines which PID and LPID are used to translate
the rest of the address (effective PID, effective LPID). The kernel
mapping at 0xC... selects quadrant 3, which uses PID=0 and LPID=0. So
the kernel page tables are installed in the PID 0 process table entry.

An address at 0x0... selects quadrant 0, which uses PID=PIDR for
translating the rest of the address (that is, it uses the value of the
PIDR register as the effective PID). If PIDR=0, then the translation
is performed with the PID 0 process table entry page tables. This is
the kernel mapping, so we effectively get another copy of the kernel
address space at 0. A NULL pointer access will access physical memory
address 0.

To prevent duplicating the kernel address space in quadrant 0, this
patch allocates a guard PID containing no translations, and
initializes PIDR with this during boot, before the MMU is switched on.
Any kernel access to quadrant 0 will use this guard PID for
translation and find no valid mappings, and therefore fault.

After boot, this PID will be switchd away to user context PIDs, but
those contain user mappings (and usually NULL pointer protection)
rather than kernel mapping, which is much safer (and by design). It
may be in future this is tightened further, which the guard PID could
be used for.

Commit 371b8044 ("powerpc/64s: Initialize ISAv3 MMU registers before
setting partition table"), introduced this problem because it zeroes
PIDR at boot. However previously the value was inherited from firmware
or kexec, which is not robust and can be zero (e.g., mambo).

Fixes: 371b80447f ("powerpc/64s: Initialize ISAv3 MMU registers before setting partition table")
Cc: stable@vger.kernel.org # v4.15+
Reported-by: Florian Weimer <fweimer@redhat.com>
Tested-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-08 23:56:11 +11:00
Nathan Fontenot 1d9a090783 powerpc/numa: Invalidate numa_cpu_lookup_table on cpu remove
When DLPAR removing a CPU, the unmapping of the cpu from a node in
unmap_cpu_from_node() should also invalidate the CPUs entry in the
numa_cpu_lookup_table. There is not a guarantee that on a subsequent
DLPAR add of the CPU the associativity will be the same and thus
could be in a different node. Invalidating the entry in the
numa_cpu_lookup_table causes the associativity to be read from the
device tree at the time of the add.

The current behavior of not invalidating the CPUs entry in the
numa_cpu_lookup_table can result in scenarios where the the topology
layout of CPUs in the partition does not match the device tree
or the topology reported by the HMC.

This bug looks like it was introduced in 2004 in the commit titled
"ppc64: cpu hotplug notifier for numa", which is 6b15e4e87e32 in the
linux-fullhist tree. Hence tag it for all stable releases.

Cc: stable@vger.kernel.org
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>
2018-02-08 23:56:10 +11:00
Ingo Molnar 8284507916 Merge branch 'linus' into sched/urgent, to resolve conflicts
Conflicts:
	arch/arm64/kernel/entry.S
	arch/x86/Kconfig
	include/linux/sched/mm.h
	kernel/fork.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-06 21:12:31 +01:00