Commit Graph

3025 Commits

Author SHA1 Message Date
Nicolas Pitre 77c5b5da02 kmap_atomic_to_page() has no users, remove it
Removal started in commit 5bbeed12bd ("sparc32: drop unused
kmap_atomic_to_page").  Let's do it across the whole tree.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-09 15:11:24 -08:00
Linus Torvalds 2f4bf528ec Merge tag 'powerpc-4.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:

 - Kconfig: remove BE-only platforms from LE kernel build from Boqun
   Feng
 - Refresh ps3_defconfig from Geoff Levand
 - Emit GNU & SysV hashes for the vdso from Michael Ellerman
 - Define an enum for the bolted SLB indexes from Anshuman Khandual
 - Use a local to avoid multiple calls to get_slb_shadow() from Michael
   Ellerman
 - Add gettimeofday() benchmark from Michael Neuling
 - Avoid link stack corruption in __get_datapage() from Michael Neuling
 - Add virt_to_pfn and use this instead of opencoding from Aneesh Kumar
   K.V
 - Add ppc64le_defconfig from Michael Ellerman
 - pseries: extract of_helpers module from Andy Shevchenko
 - Correct string length in pseries_of_derive_parent() from Nathan
   Fontenot
 - Free the MSI bitmap if it was slab allocated from Denis Kirjanov
 - Shorten irq_chip name for the SIU from Christophe Leroy
 - Wait 1s for secondaries to enter OPAL during kexec from Samuel
   Mendoza-Jonas
 - Fix _ALIGN_* errors due to type difference, from Aneesh Kumar K.V
 - powerpc/pseries/hvcserver: don't memset pi_buff if it is null from
   Colin Ian King
 - Disable hugepd for 64K page size, from Aneesh Kumar K.V
 - Differentiate between hugetlb and THP during page walk from Aneesh
   Kumar K.V
 - Make PCI non-optional for pseries from Michael Ellerman
 - Individual System V IPC system calls from Sam bobroff
 - Add selftest of unmuxed IPC calls from Michael Ellerman
 - discard .exit.data at runtime from Stephen Rothwell
 - Delete old orphaned PrPMC 280/2800 DTS and boot file, from Paul
   Gortmaker
 - Use of_get_next_parent to simplify code from Christophe Jaillet
 - Paginate some xmon output from Sam bobroff
 - Add some more elements to the xmon PACA dump from Michael Ellerman
 - Allow the tm-syscall selftest to build with old headers from Michael
   Ellerman
 - Run EBB selftests only on POWER8 from Denis Kirjanov
 - Drop CONFIG_TUNE_CELL in favour of CONFIG_CELL_CPU from Michael
   Ellerman
 - Avoid reference to potentially freed memory in prom.c from Christophe
   Jaillet
 - Quieten boot wrapper output with run_cmd from Geoff Levand
 - EEH fixes and cleanups from Gavin Shan
 - Fix recursive fenced PHB on Broadcom shiner adapter from Gavin Shan
 - Use of_get_next_parent() in of_get_ibm_chip_id() from Michael
   Ellerman
 - Fix section mismatch warning in msi_bitmap_alloc() from Denis
   Kirjanov
 - Fix ps3-lpm white space from Rudhresh Kumar J
 - Fix ps3-vuart null dereference from Colin King
 - nvram: Add missing kfree in error path from Christophe Jaillet
 - nvram: Fix function name in some errors messages, from Christophe
   Jaillet
 - drivers/macintosh: adb: fix misleading Kconfig help text from Aaro
   Koskinen
 - agp/uninorth: fix a memleak in create_gatt_table from Denis Kirjanov
 - cxl: Free virtual PHB when removing from Andrew Donnellan
 - scripts/kconfig/Makefile: Allow KBUILD_DEFCONFIG to be a target from
   Michael Ellerman
 - scripts/kconfig/Makefile: Fix KBUILD_DEFCONFIG check when building
   with O= from Michael Ellerman
 - Freescale updates from Scott: Highlights include 64-bit book3e
   kexec/kdump support, a rework of the qoriq clock driver, device tree
   changes including qoriq fman nodes, support for a new 85xx board, and
   some fixes.
 - MPC5xxx updates from Anatolij: Highlights include a driver for
   MPC512x LocalPlus Bus FIFO with its device tree binding
   documentation, mpc512x device tree updates and some minor fixes.

* tag 'powerpc-4.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (106 commits)
  powerpc/msi: Fix section mismatch warning in msi_bitmap_alloc()
  powerpc/prom: Use of_get_next_parent() in of_get_ibm_chip_id()
  powerpc/pseries: Correct string length in pseries_of_derive_parent()
  powerpc/e6500: hw tablewalk: make sure we invalidate and write to the same tlb entry
  powerpc/mpc85xx: Add FSL QorIQ DPAA FMan support to the SoC device tree(s)
  powerpc/mpc85xx: Create dts components for the FSL QorIQ DPAA FMan
  powerpc/fsl: Add #clock-cells and clockgen label to clockgen nodes
  powerpc: handle error case in cpm_muram_alloc()
  powerpc: mpic: use IRQCHIP_SKIP_SET_WAKE instead of redundant mpic_irq_set_wake
  powerpc/book3e-64: Enable kexec
  powerpc/book3e-64/kexec: Set "r4 = 0" when entering spinloop
  powerpc/booke: Only use VIRT_PHYS_OFFSET on booke32
  powerpc/book3e-64/kexec: Enable SMP release
  powerpc/book3e-64/kexec: create an identity TLB mapping
  powerpc/book3e-64: Don't limit paca to 256 MiB
  powerpc/book3e/kdump: Enable crash_kexec_wait_realmode
  powerpc/book3e: support CONFIG_RELOCATABLE
  powerpc/booke64: Fix args to copy_and_flush
  powerpc/book3e-64: rename interrupt_end_book3e with __end_interrupts
  powerpc/e6500: kexec: Handle hardware threads
  ...
2015-11-05 23:38:43 -08:00
Linus Torvalds 2e3078af2c Merge branch 'akpm' (patches from Andrew)
Merge patch-bomb from Andrew Morton:

 - inotify tweaks

 - some ocfs2 updates (many more are awaiting review)

 - various misc bits

 - kernel/watchdog.c updates

 - Some of mm.  I have a huge number of MM patches this time and quite a
   lot of it is quite difficult and much will be held over to next time.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
  selftests: vm: add tests for lock on fault
  mm: mlock: add mlock flags to enable VM_LOCKONFAULT usage
  mm: introduce VM_LOCKONFAULT
  mm: mlock: add new mlock system call
  mm: mlock: refactor mlock, munlock, and munlockall code
  kasan: always taint kernel on report
  mm, slub, kasan: enable user tracking by default with KASAN=y
  kasan: use IS_ALIGNED in memory_is_poisoned_8()
  kasan: Fix a type conversion error
  lib: test_kasan: add some testcases
  kasan: update reference to kasan prototype repo
  kasan: move KASAN_SANITIZE in arch/x86/boot/Makefile
  kasan: various fixes in documentation
  kasan: update log messages
  kasan: accurately determine the type of the bad access
  kasan: update reported bug types for kernel memory accesses
  kasan: update reported bug types for not user nor kernel memory accesses
  mm/kasan: prevent deadlock in kasan reporting
  mm/kasan: don't use kasan shadow pointer in generic functions
  mm/kasan: MODULE_VADDR is not available on all archs
  ...
2015-11-05 23:10:54 -08:00
Eric B Munson b0f205c2a3 mm: mlock: add mlock flags to enable VM_LOCKONFAULT usage
The previous patch introduced a flag that specified pages in a VMA should
be placed on the unevictable LRU, but they should not be made present when
the area is created.  This patch adds the ability to set this state via
the new mlock system calls.

We add MLOCK_ONFAULT for mlock2 and MCL_ONFAULT for mlockall.
MLOCK_ONFAULT will set the VM_LOCKONFAULT modifier for VM_LOCKED.
MCL_ONFAULT should be used as a modifier to the two other mlockall flags.
When used with MCL_CURRENT, all current mappings will be marked with
VM_LOCKED | VM_LOCKONFAULT.  When used with MCL_FUTURE, the mm->def_flags
will be marked with VM_LOCKED | VM_LOCKONFAULT.  When used with both
MCL_CURRENT and MCL_FUTURE, all current mappings and mm->def_flags will be
marked with VM_LOCKED | VM_LOCKONFAULT.

Prior to this patch, mlockall() will unconditionally clear the
mm->def_flags any time it is called without MCL_FUTURE.  This behavior is
maintained after adding MCL_ONFAULT.  If a call to mlockall(MCL_FUTURE) is
followed by mlockall(MCL_CURRENT), the mm->def_flags will be cleared and
new VMAs will be unlocked.  This remains true with or without MCL_ONFAULT
in either mlockall() invocation.

munlock() will unconditionally clear both vma flags.  munlockall()
unconditionally clears for VMA flags on all VMAs and in the mm->def_flags
field.

Signed-off-by: Eric B Munson <emunson@akamai.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05 19:34:48 -08:00
Linus Torvalds 933425fb00 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
 "First batch of KVM changes for 4.4.

  s390:
     A bunch of fixes and optimizations for interrupt and time handling.

  PPC:
     Mostly bug fixes.

  ARM:
     No big features, but many small fixes and prerequisites including:

      - a number of fixes for the arch-timer

      - introducing proper level-triggered semantics for the arch-timers

      - a series of patches to synchronously halt a guest (prerequisite
        for IRQ forwarding)

      - some tracepoint improvements

      - a tweak for the EL2 panic handlers

      - some more VGIC cleanups getting rid of redundant state

  x86:
     Quite a few changes:

      - support for VT-d posted interrupts (i.e. PCI devices can inject
        interrupts directly into vCPUs).  This introduces a new
        component (in virt/lib/) that connects VFIO and KVM together.
        The same infrastructure will be used for ARM interrupt
        forwarding as well.

      - more Hyper-V features, though the main one Hyper-V synthetic
        interrupt controller will have to wait for 4.5.  These will let
        KVM expose Hyper-V devices.

      - nested virtualization now supports VPID (same as PCID but for
        vCPUs) which makes it quite a bit faster

      - for future hardware that supports NVDIMM, there is support for
        clflushopt, clwb, pcommit

      - support for "split irqchip", i.e.  LAPIC in kernel +
        IOAPIC/PIC/PIT in userspace, which reduces the attack surface of
        the hypervisor

      - obligatory smattering of SMM fixes

      - on the guest side, stable scheduler clock support was rewritten
        to not require help from the hypervisor"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits)
  KVM: VMX: Fix commit which broke PML
  KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0()
  KVM: x86: allow RSM from 64-bit mode
  KVM: VMX: fix SMEP and SMAP without EPT
  KVM: x86: move kvm_set_irq_inatomic to legacy device assignment
  KVM: device assignment: remove pointless #ifdefs
  KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic
  KVM: x86: zero apic_arb_prio on reset
  drivers/hv: share Hyper-V SynIC constants with userspace
  KVM: x86: handle SMBASE as physical address in RSM
  KVM: x86: add read_phys to x86_emulate_ops
  KVM: x86: removing unused variable
  KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs
  KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()
  KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings
  KVM: arm/arm64: Optimize away redundant LR tracking
  KVM: s390: use simple switch statement as multiplexer
  KVM: s390: drop useless newline in debugging data
  KVM: s390: SCA must not cross page boundaries
  KVM: arm: Do not indent the arguments of DECLARE_BITMAP
  ...
2015-11-05 16:26:26 -08:00
Michael Ellerman 8bdf2023e2 Merge branch 'next' of git://git.denx.de/linux-denx-agust into next
MPC5xxx updates from Anatolij:

"Highlights include a driver for MPC512x LocalPlus Bus FIFO with its
device tree binding documentation, mpc512x device tree updates and some
minor fixes."
2015-11-05 19:35:12 +11:00
Paolo Bonzini 197a4f4b06 Merge tag 'kvm-arm-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/ARM Changes for v4.4-rc1

Includes a number of fixes for the arch-timer, introducing proper
level-triggered semantics for the arch-timers, a series of patches to
synchronously halt a guest (prerequisite for IRQ forwarding), some tracepoint
improvements, a tweak for the EL2 panic handlers, some more VGIC cleanups
getting rid of redundant state, and finally a stylistic change that gets rid of
some ctags warnings.

Conflicts:
	arch/x86/include/asm/kvm_host.h
2015-11-04 16:24:17 +01:00
Kevin Hao e1f580e8ce powerpc/e6500: hw tablewalk: make sure we invalidate and write to the same tlb entry
In order to workaround Erratum A-008139, we have to invalidate the
tlb entry with tlbilx before overwriting. Due to the performance
consideration, we don't add any memory barrier when acquire/release
the tcd lock. This means the two load instructions for esel_next do
have the possibility to return different value. This is definitely
not acceptable due to the Erratum A-008139. We have two options to
fix this issue:
  a) Add memory barrier when acquire/release tcd lock to order the
     load/store to esel_next.
  b) Just make sure to invalidate and write to the same tlb entry and
     tolerate the race that we may get the wrong value and overwrite
     the tlb entry just updated by the other thread.

We observe better performance using option b. So reserve an additional
register to save the value of the esel_next.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
2015-10-27 18:14:40 -05:00
Scott Wood 43f2cfcce2 Merge branch 'clock' into HEAD
This is a major overhaul of the clk-qoriq driver, which I'm merging
via PPC with Stephen Boyd's ack in order to apply subsequent PPC patches
that depend on it.
2015-10-27 18:14:16 -05:00
Scott Wood ffda09a994 powerpc/booke: Only use VIRT_PHYS_OFFSET on booke32
The way VIRT_PHYS_OFFSET is not correct on book3e-64, because
it does not account for CONFIG_RELOCATABLE other than via the
32-bit-only virt_phys_offset.

book3e-64 can (and if the comment about a GCC miscompilation is still
relevant, should) use the normal ppc64 __va/__pa.

At this point, only booke-32 will use VIRT_PHYS_OFFSET, so given the
issues with its calculation, restrict its definition to booke-32.

Signed-off-by: Scott Wood <scottwood@freescale.com>
2015-10-27 18:13:29 -05:00
Tiejun Chen 1cb6e06492 powerpc/book3e: support CONFIG_RELOCATABLE
book3e is different with book3s since 3s includes the exception
vectors code in head_64.S as it relies on absolute addressing
which is only possible within this compilation unit. So we have
to get that label address with got.

And when boot a relocated kernel, we should reset ipvr properly again
after .relocate.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
[scottwood: cleanup and ifdef removal]
Signed-off-by: Scott Wood <scottwood@freescale.com>
2015-10-27 18:13:27 -05:00
Linus Torvalds a2c01ed5d4 Merge tag 'powerpc-4.3-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:

 - Revert "Use the POWER8 Micro Partition Prefetch Engine in KVM HV on
   POWER8" from Paul
 - Handle irq_happened flag correctly in off-line loop from Paul
 - Validate rtas.entry before calling enter_rtas() from Vasant

* tag 'powerpc-4.3-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/rtas: Validate rtas.entry before calling enter_rtas()
  powerpc/powernv: Handle irq_happened flag correctly in off-line loop
  powerpc: Revert "Use the POWER8 Micro Partition Prefetch Engine in KVM HV on POWER8"
2015-10-23 18:49:51 +09:00
Christoffer Dall 3217f7c25b KVM: Add kvm_arch_vcpu_{un}blocking callbacks
Some times it is useful for architecture implementations of KVM to know
when the VCPU thread is about to block or when it comes back from
blocking (arm/arm64 needs to know this to properly implement timers, for
example).

Therefore provide a generic architecture callback function in line with
what we do elsewhere for KVM generic-arch interactions.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22 23:01:41 +02:00
Uwe Kleine-König ffcea122c4 powerpc: mpc512x: drop bogus and unused psc register bit definitions
These were introduced in commit 25ae3a0739 ("[POWERPC] mpc512x: Add
MPC512x PSC support to MPC52xx psc driver") and never used. Moreover
according to the datasheet[1] MEMERROR is bit 25 (0x40) and ORERR is
bit 27 (0x10).

[1] MPC5125RM Rev. 2; 11/2009

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
2015-10-22 16:06:08 +02:00
Alexander Popov 1a4bb93f79 powerpc/512x: add LocalPlus Bus FIFO device driver
This driver for Freescale MPC512x LocalPlus Bus FIFO (called SCLPC
in the Reference Manual) allows Direct Memory Access transfers
between RAM and peripheral devices on LocalPlus Bus.

Signed-off-by: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
2015-10-22 15:19:40 +02:00
Scott Wood 9484865447 powerpc/fsl: Move fsl_guts.h out of arch/powerpc
Freescale's Layerscape ARM chips use the same structure.

Signed-off-by: Scott Wood <scottwood@freescale.com>
2015-10-21 18:05:50 -05:00
Paul Mackerras 23316316c1 powerpc: Revert "Use the POWER8 Micro Partition Prefetch Engine in KVM HV on POWER8"
This reverts commit 9678cdaae9 ("Use the POWER8 Micro Partition
Prefetch Engine in KVM HV on POWER8") because the original commit had
multiple, partly self-cancelling bugs, that could cause occasional
memory corruption.

In fact the logmpp instruction was incorrectly using register r0 as the
source of the buffer address and operation code, and depending on what
was in r0, it would either do nothing or corrupt the 64k page pointed to
by r0.

The logmpp instruction encoding and the operation code definitions could
be corrected, but then there is the problem that there is no clearly
defined way to know when the hardware has finished writing to the
buffer.

The original commit attempted to work around this by aborting the
write-out before starting the prefetch, but this is ineffective in the
case where the virtual core is now executing on a different physical
core from the one where the write-out was initiated.

These problems plus advice from the hardware designers not to use the
function (since the measured performance improvement from using the
feature was actually mostly negative), mean that reverting the code is
the best option.

Fixes: 9678cdaae9 ("Use the POWER8 Micro Partition Prefetch Engine in KVM HV on POWER8")
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-21 20:50:30 +11:00
Linus Torvalds ebb65c81e1 Merge tag 'powerpc-4.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
 - Re-enable CONFIG_SCSI_DH in our defconfigs
 - Remove unused os_area_db_id_video_mode
 - cxl: fix leak of IRQ names in cxl_free_afu_irqs() from Andrew
 - cxl: fix leak of ctx->irq_bitmap when releasing context via kernel API from Andrew
 - cxl: fix leak of ctx->mapping when releasing kernel API contexts from Andrew
 - cxl: Workaround malformed pcie packets on some cards from Philippe
 - cxl: Fix number of allocated pages in SPA from Christophe Lombard
 - Fix checkstop in native_hpte_clear() with lockdep from Cyril
 - Panic on unhandled Machine Check on powernv from Daniel
 - selftests/powerpc: Fix build failure of load_unaligned_zeropad test

* tag 'powerpc-4.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  selftests/powerpc: Fix build failure of load_unaligned_zeropad test
  powerpc/powernv: Panic on unhandled Machine Check
  powerpc: Fix checkstop in native_hpte_clear() with lockdep
  cxl: Fix number of allocated pages in SPA
  cxl: Workaround malformed pcie packets on some cards
  cxl: fix leak of ctx->mapping when releasing kernel API contexts
  cxl: fix leak of ctx->irq_bitmap when releasing context via kernel API
  cxl: fix leak of IRQ names in cxl_free_afu_irqs()
  powerpc/ps3: Remove unused os_area_db_id_video_mode
  powerpc/configs: Re-enable CONFIG_SCSI_DH
2015-10-16 12:07:43 -07:00
Sam bobroff a34236155a powerpc: Individual System V IPC system calls
This patch provides individual system call numbers for the following
System V IPC system calls, on PowerPC, so that they do not need to be
multiplexed:
* semop, semget, semctl, semtimedop
* msgsnd, msgrcv, msgget, msgctl
* shmat, shmdt, shmget, shmctl

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-15 20:31:57 +11:00
Tudor Laurentiu 2daab50e17 KVM: PPC: e500: Emulate TMCFG0 TMRN register
Emulate TMCFG0 TMRN register exposing one HW thread per vcpu.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
[Laurentiu.Tudor@freescale.com: rebased on latest kernel, use
 define instead of hardcoded value, moved code in own function]
Signed-off-by: Laurentiu Tudor <Laurentiu.Tudor@freescale.com>
Acked-by: Scott Wood <scotttwood@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2015-10-15 15:58:16 +11:00
Tudor Laurentiu 6a14c22224 powerpc/e6500: add TMCFG0 register definition
The register is not currently used in the base kernel
but will be in a forthcoming kvm patch.

Signed-off-by: Laurentiu Tudor <Laurentiu.Tudor@freescale.com>
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2015-10-15 15:58:16 +11:00
Aneesh Kumar K.V 891121e6c0 powerpc/mm: Differentiate between hugetlb and THP during page walk
We need to properly identify whether a hugepage is an explicit or
a transparent hugepage in follow_huge_addr(). We used to depend
on hugepage shift argument to do that. But in some case that can
result in wrong results. For ex:

On finding a transparent hugepage we set hugepage shift to PMD_SHIFT.
But we can end up clearing the thp pte, via pmdp_huge_get_and_clear.
We do prevent reusing the pfn page via the usage of
kick_all_cpus_sync(). But that happens after we updated the pte to 0.
Hence in follow_huge_addr() we can find hugepage shift set, but transparent
huge page check fail for a thp pte.

NOTE: We fixed a variant of this race against thp split in commit
691e95fd73
("powerpc/mm/thp: Make page table walk safe against thp split/collapse")

Without this patch, we may hit the BUG_ON(flags & FOLL_GET) in
follow_page_mask occasionally.

In the long term, we may want to switch ppc64 64k page size config to
enable CONFIG_ARCH_WANT_GENERAL_HUGETLB

Reported-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-12 15:30:09 +11:00
Aneesh Kumar K.V ec2640b114 powerpc/mm: Disable hugepd for 64K page size.
After commit e2b3d202d1
("powerpc: Switch 16GB and 16MB explicit hugepages to a
different page table format"), we don't need to support
is_hugepd() for 64K page size.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-12 15:29:59 +11:00
Aneesh Kumar K.V f78f7ed726 powerpc: Fix _ALIGN_* errors due to type difference.
This avoid errors like

        unsigned int usize = 1 << 30;
        int size = 1 << 30;
        unsigned long addr = 64UL << 30 ;

        value = _ALIGN_DOWN(addr, usize); -> 0
        value = _ALIGN_DOWN(addr, size);  -> 0x1000000000

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-09 08:02:25 +11:00
Cyril Bur fdf880a608 powerpc: Fix checkstop in native_hpte_clear() with lockdep
native_hpte_clear() is called in real mode from two places:
- Early in boot during htab initialisation if firmware assisted dump is
  active.
- Late in the kexec path.

In both contexts there is no need to disable interrupts are they are
already disabled. Furthermore, locking around the tlbie() is only required
for pre POWER5 hardware.

On POWER5 or newer hardware concurrent tlbie()s work as expected and on pre
POWER5 hardware concurrent tlbie()s could result in deadlock. This code
would only be executed at crashdump time, during which all bets are off,
concurrent tlbie()s are unlikely and taking locks is unsafe therefore the
best course of action is to simply do nothing. Concurrent tlbie()s are not
possible in the first case as secondary CPUs have not come up yet.

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-09 08:01:38 +11:00