Commit Graph

2341 Commits

Author SHA1 Message Date
Christophe Leroy d80ae83f1f powerpc/ptdump: Fix W+X verification
Verification cannot rely on simple bit checking because on some
platforms PAGE_RW is 0, checking that a page is not W means
checking that PAGE_RO is set instead of checking that PAGE_RW
is not set.

Use pte helpers instead of checking bits.

Fixes: 453d87f6a8 ("powerpc/mm: Warn if W+X pages found on boot")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0d894839fdbb19070f0e1e4140363be4f2bb62fc.1578989540.git.christophe.leroy@c-s.fr
2020-01-23 21:31:13 +11:00
Christophe Leroy e26ad936dd powerpc/ptdump: Fix W+X verification call in mark_rodata_ro()
ptdump_check_wx() also have to be called when pages are mapped
by blocks.

Fixes: 453d87f6a8 ("powerpc/mm: Warn if W+X pages found on boot")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/37517da8310f4457f28921a4edb88fb21d27b62a.1578989531.git.christophe.leroy@c-s.fr
2020-01-23 21:31:12 +11:00
Christophe Leroy 1e1c8b2cc3 powerpc/ptdump: don't entirely rebuild kernel when selecting CONFIG_PPC_DEBUG_WX
Selecting CONFIG_PPC_DEBUG_WX only impacts ptdump and pgtable_32/64
init calls. Declaring related functions in asm/pgtable.h implies
rebuilding almost everything.

Move ptdump_check_wx() declaration in mm/mmu_decl.h

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bf34fd9dca61eadf9a134a9f89ebbc162cfd5f86.1578986011.git.christophe.leroy@c-s.fr
2020-01-23 21:31:11 +11:00
Russell Currey 970d54f99c powerpc/book3s64/hash: Disable 16M linear mapping size if not aligned
With STRICT_KERNEL_RWX on in a relocatable kernel under the hash MMU,
if the position the kernel is loaded at is not 16M aligned things go
horribly wrong. Specifically hash__mark_initmem_nx() will call
hash__change_memory_range() which then aligns down the start address,
and due to the text not being 16M aligned causes some of the kernel
text to be marked non-executable.

We can avoid this when selecting the linear mapping size, so do so and
print a warning. I tested this for various alignments and as long as
the position is 64K aligned it's fine (the base requirement for
powerpc).

Signed-off-by: Russell Currey <ruscur@russell.cc>
[mpe: Add details of the failure mode]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191224064126.183670-1-ruscur@russell.cc
2020-01-16 14:59:36 +10:00
David Hildenbrand feee6b2989 mm/memory_hotplug: shrink zones when offlining memory
We currently try to shrink a single zone when removing memory.  We use
the zone of the first page of the memory we are removing.  If that
memmap was never initialized (e.g., memory was never onlined), we will
read garbage and can trigger kernel BUGs (due to a stale pointer):

    BUG: unable to handle page fault for address: 000000000000353d
    #PF: supervisor write access in kernel mode
    #PF: error_code(0x0002) - not-present page
    PGD 0 P4D 0
    Oops: 0002 [#1] SMP PTI
    CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.3.0-rc5-next-20190820+ #317
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.4
    Workqueue: kacpi_hotplug acpi_hotplug_work_fn
    RIP: 0010:clear_zone_contiguous+0x5/0x10
    Code: 48 89 c6 48 89 c3 e8 2a fe ff ff 48 85 c0 75 cf 5b 5d c3 c6 85 fd 05 00 00 01 5b 5d c3 0f 1f 840
    RSP: 0018:ffffad2400043c98 EFLAGS: 00010246
    RAX: 0000000000000000 RBX: 0000000200000000 RCX: 0000000000000000
    RDX: 0000000000200000 RSI: 0000000000140000 RDI: 0000000000002f40
    RBP: 0000000140000000 R08: 0000000000000000 R09: 0000000000000001
    R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000140000
    R13: 0000000000140000 R14: 0000000000002f40 R15: ffff9e3e7aff3680
    FS:  0000000000000000(0000) GS:ffff9e3e7bb00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 000000000000353d CR3: 0000000058610000 CR4: 00000000000006e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
     __remove_pages+0x4b/0x640
     arch_remove_memory+0x63/0x8d
     try_remove_memory+0xdb/0x130
     __remove_memory+0xa/0x11
     acpi_memory_device_remove+0x70/0x100
     acpi_bus_trim+0x55/0x90
     acpi_device_hotplug+0x227/0x3a0
     acpi_hotplug_work_fn+0x1a/0x30
     process_one_work+0x221/0x550
     worker_thread+0x50/0x3b0
     kthread+0x105/0x140
     ret_from_fork+0x3a/0x50
    Modules linked in:
    CR2: 000000000000353d

Instead, shrink the zones when offlining memory or when onlining failed.
Introduce and use remove_pfn_range_from_zone(() for that.  We now
properly shrink the zones, even if we have DIMMs whereby

 - Some memory blocks fall into no zone (never onlined)

 - Some memory blocks fall into multiple zones (offlined+re-onlined)

 - Multiple memory blocks that fall into different zones

Drop the zone parameter (with a potential dubious value) from
__remove_pages() and __remove_section().

Link: http://lkml.kernel.org/r/20191006085646.5768-6-david@redhat.com
Fixes: f1dd2cd13c ("mm, memory_hotplug: do not associate hotadded memory to zones until online")	[visible after d0dc12e86b]
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: <stable@vger.kernel.org>	[5.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-04 13:55:08 -08:00
Michael Ellerman 91a063c956 powerpc/mm: Mark get_slice_psize() & slice_addr_is_low() as notrace
These slice routines are called from the SLB miss handler, which can
lead to warnings from the IRQ code, because we have not reconciled the
IRQ state properly:

  WARNING: CPU: 72 PID: 30150 at arch/powerpc/kernel/irq.c:258 arch_local_irq_restore.part.0+0xcc/0x100
  Modules linked in:
  CPU: 72 PID: 30150 Comm: ftracetest Not tainted 5.5.0-rc2-gcc9x-g7e0165b2f1a9 #1
  NIP:  c00000000001d83c LR: c00000000029ab90 CTR: c00000000026cf90
  REGS: c0000007eee3b960 TRAP: 0700   Not tainted  (5.5.0-rc2-gcc9x-g7e0165b2f1a9)
  MSR:  8000000000021033 <SF,ME,IR,DR,RI,LE>  CR: 22242844  XER: 20000000
  CFAR: c00000000001d780 IRQMASK: 0
  ...
  NIP arch_local_irq_restore.part.0+0xcc/0x100
  LR  trace_graph_entry+0x270/0x340
  Call Trace:
    trace_graph_entry+0x254/0x340 (unreliable)
    function_graph_enter+0xe4/0x1a0
    prepare_ftrace_return+0xa0/0x130
    ftrace_graph_caller+0x44/0x94	# (get_slice_psize())
    slb_allocate_user+0x7c/0x100
    do_slb_fault+0xf8/0x300
    instruction_access_slb_common+0x140/0x180

Fixes: 48e7b76957 ("powerpc/64s/hash: Convert SLB miss handlers to C")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191221121337.4894-1-mpe@ellerman.id.au
2019-12-23 21:12:51 +11:00
Christophe Leroy 0601546f23 powerpc/8xx: fix bogus __init on mmu_mapin_ram_chunk()
Remove __init qualifier for mmu_mapin_ram_chunk() as it is called by
mmu_mark_initmem_nx() and mmu_mark_rodata_ro() which are not __init
functions.

At the same time, mark it static as it is only used in this file.

Reported-by: kbuild test robot <lkp@intel.com>
Fixes: a2227a2777 ("powerpc/32: Don't populate page tables for block mapped pages except on the 8xx")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/56648921986a6b3e7315b1fbbf4684f21bd2dea8.1576310997.git.christophe.leroy@c-s.fr
2019-12-16 23:15:16 +11:00
Mike Rapoport 8fabc62323 powerpc: Ensure that swiotlb buffer is allocated from low memory
Some powerpc platforms (e.g. 85xx) limit DMA-able memory way below 4G.
If a system has more physical memory than this limit, the swiotlb
buffer is not addressable because it is allocated from memblock using
top-down mode.

Force memblock to bottom-up mode before calling swiotlb_init() to
ensure that the swiotlb buffer is DMA-able.

Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191204123524.22919-1-rppt@kernel.org
2019-12-13 21:27:55 +11:00
Aneesh Kumar K.V 6f4679b956 powerpc/pmem: Fix kernel crash due to wrong range value usage in flush_dcache_range
This patch fix the below kernel crash.

 BUG: Unable to handle kernel data access on read at 0xc000000380000000
 Faulting instruction address: 0xc00000000008b6f0
cpu 0x5: Vector: 300 (Data Access) at [c0000000d8587790]
    pc: c00000000008b6f0: arch_remove_memory+0x150/0x210
    lr: c00000000008b720: arch_remove_memory+0x180/0x210
    sp: c0000000d8587a20
   msr: 800000000280b033
   dar: c000000380000000
 dsisr: 40000000
  current = 0xc0000000d8558600
  paca    = 0xc00000000fff8f00   irqmask: 0x03   irq_happened: 0x01
    pid   = 1220, comm = ndctl
enter ? for help
 memunmap_pages+0x33c/0x410
 devm_action_release+0x30/0x50
 release_nodes+0x30c/0x3a0
 device_release_driver_internal+0x178/0x240
 unbind_store+0x74/0x190
 drv_attr_store+0x44/0x60
 sysfs_kf_write+0x74/0xa0
 kernfs_fop_write+0x1b0/0x260
 __vfs_write+0x3c/0x70
 vfs_write+0xe4/0x200
 ksys_write+0x7c/0x140
 system_call+0x5c/0x68

Fixes: 076265907c ("powerpc: Chunk calls to flush_dcache_range in arch_*_memory")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191204052909.59145-1-aneesh.kumar@linux.ibm.com
2019-12-05 00:11:45 +11:00
Linus Torvalds 596cf45cbf Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:
 "Incoming:

   - a small number of updates to scripts/, ocfs2 and fs/buffer.c

   - most of MM

  I still have quite a lot of material (mostly not MM) staged after
  linux-next due to -next dependencies. I'll send those across next week
  as the preprequisites get merged up"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (135 commits)
  mm/page_io.c: annotate refault stalls from swap_readpage
  mm/Kconfig: fix trivial help text punctuation
  mm/Kconfig: fix indentation
  mm/memory_hotplug.c: remove __online_page_set_limits()
  mm: fix typos in comments when calling __SetPageUptodate()
  mm: fix struct member name in function comments
  mm/shmem.c: cast the type of unmap_start to u64
  mm: shmem: use proper gfp flags for shmem_writepage()
  mm/shmem.c: make array 'values' static const, makes object smaller
  userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK
  fs/userfaultfd.c: wp: clear VM_UFFD_MISSING or VM_UFFD_WP during userfaultfd_register()
  userfaultfd: wrap the common dst_vma check into an inlined function
  userfaultfd: remove unnecessary WARN_ON() in __mcopy_atomic_hugetlb()
  userfaultfd: use vma_pagesize for all huge page size calculation
  mm/madvise.c: use PAGE_ALIGN[ED] for range checking
  mm/madvise.c: replace with page_size() in madvise_inject_error()
  mm/mmap.c: make vma_merge() comment more easy to understand
  mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops
  autonuma: reduce cache footprint when scanning page tables
  autonuma: fix watermark checking in migrate_balanced_pgdat()
  ...
2019-12-01 20:36:41 -08:00
Mike Kravetz 997cdcb068 powerpc/mm: remove pmd_huge/pud_huge stubs and include hugetlb.h
Patch series "hugetlbfs: convert macros to static inline, fix sparse
warning".

The definition for huge_pte_offset() in <linux/hugetlb.h> causes a
sparse warning in the !CONFIG_HUGETLB_PAGE.  Fix this as well as
converting all macros in this block of definitions to static inlines for
better type checking.

When making the above changes, build errors were found in powerpc due to
duplicate definitions.  A separate powerpc specific patch is included as
a requisite to remove the definitions and get them from
<linux/hugetlb.h>.

This patch (of 2):

This removes the power specific stubs created by commit aad71e3928
("powerpc/mm: Fix build break with RADIX=y & HUGETLBFS=n") used when
!CONFIG_HUGETLB_PAGE.  Instead, it addresses the build break by getting
the definitions from <linux/hugetlb.h>.  This allows the macros in
<linux/hugetlb.h> to be replaced with static inlines.

Link: http://lkml.kernel.org/r/20191112194558.139389-2-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ben Dooks <ben.dooks@codethink.co.uk>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01 12:59:08 -08:00
Linus Torvalds 7794b1d418 powerpc updates for 5.5
Highlights:
 
  - Infrastructure for secure boot on some bare metal Power9 machines. The
    firmware support is still in development, so the code here won't actually
    activate secure boot on any existing systems.
 
  - A change to xmon (our crash handler / pseudo-debugger) to restrict it to
    read-only mode when the kernel is lockdown'ed, otherwise it's trivial to drop
    into xmon and modify kernel data, such as the lockdown state.
 
  - Support for KASLR on 32-bit BookE machines (Freescale / NXP).
 
  - Fixes for our flush_icache_range() and __kernel_sync_dicache() (VDSO) to work
    with memory ranges >4GB.
 
  - Some reworks of the pseries CMM (Cooperative Memory Management) driver to
    make it behave more like other balloon drivers and enable some cleanups of
    generic mm code.
 
  - A series of fixes to our hardware breakpoint support to properly handle
    unaligned watchpoint addresses.
 
 Plus a bunch of other smaller improvements, fixes and cleanups.
 
 Thanks to:
   Alastair D'Silva, Andrew Donnellan, Aneesh Kumar K.V, Anthony Steinhauser,
   Cédric Le Goater, Chris Packham, Chris Smart, Christophe Leroy, Christopher M.
   Riedl, Christoph Hellwig, Claudio Carvalho, Daniel Axtens, David Hildenbrand,
   Deb McLemore, Diana Craciun, Eric Richter, Geert Uytterhoeven, Greg
   Kroah-Hartman, Greg Kurz, Gustavo L. F. Walbon, Hari Bathini, Harish, Jason
   Yan, Krzysztof Kozlowski, Leonardo Bras, Mathieu Malaterre, Mauro S. M.
   Rodrigues, Michal Suchanek, Mimi Zohar, Nathan Chancellor, Nathan Lynch, Nayna
   Jain, Nick Desaulniers, Oliver O'Halloran, Qian Cai, Rasmus Villemoes, Ravi
   Bangoria, Sam Bobroff, Santosh Sivaraj, Scott Wood, Thomas Huth, Tyrel
   Datwyler, Vaibhav Jain, Valentin Longchamp, YueHaibing.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCAAxFiEEJFGtCPCthwEv2Y/bUevqPMjhpYAFAl3hBycTHG1wZUBlbGxl
 cm1hbi5pZC5hdQAKCRBR6+o8yOGlgApBEACk91MEQDYJ9MF9I6uN+85qb5p4pMsp
 rGzqnpt+XFidbDAc3eP63pYfIDSo3jtkQ2YL7shAnDOTvkO0md+Vqkl9Aq/G6FIf
 lDBlwbgkXMSxS/O2Lpvfn4NZAoK6dKmiV55LSgfliM62X3e2Saeg6TR55wBTgJ6/
 SlYPDwZfcVHOAiFS3UmfB+hkiIZk+AI5Zr5VAZvT2ZmeH36yAWkq4JgJI1uAk6m1
 /7iCnlfUjx/nl/BhnA3kjjmAgGCJ5s/WuVgwFMz47XpMBWGBhLWpMh/NqDTFb8ca
 kpiVQoVPQe2xyO3pL/kOwBy6sii26ftfHDhLKMy1hJdEhVQzS5LerPIMeh1qsU8Q
 hV/Cj+jfsrS/vBDOehj3jwx93t+861PmTOqgLnpYQ6Ltrt+2B/74+fufGMHE1kI3
 Ffo7xvNw4sw6bSziDxDFqUx2P1dFN5D5EJsJsYM98ekkVAAkzNqCDRvfD2QI8Pif
 VXWPYXqtNJTrVPJA0D7Yfo9FDNwhANd0f1zi7r/U5mVXBFUyKOlGqTQSkXgMrVeK
 3I7wHPOVGgdA5UUkfcd3pcuqsY081U9E//o5PUfj8ybO5JCwly8NoatbG+xHmKia
 a72uJT8MjCo9mGCHKDrwi9l/kqms6ZSv8RP+yMhGuB52YoiGc6PpVyab5jXIUd1N
 yTtBlC0YGW1JYw==
 =JHzg
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Highlights:

   - Infrastructure for secure boot on some bare metal Power9 machines.
     The firmware support is still in development, so the code here
     won't actually activate secure boot on any existing systems.

   - A change to xmon (our crash handler / pseudo-debugger) to restrict
     it to read-only mode when the kernel is lockdown'ed, otherwise it's
     trivial to drop into xmon and modify kernel data, such as the
     lockdown state.

   - Support for KASLR on 32-bit BookE machines (Freescale / NXP).

   - Fixes for our flush_icache_range() and __kernel_sync_dicache()
     (VDSO) to work with memory ranges >4GB.

   - Some reworks of the pseries CMM (Cooperative Memory Management)
     driver to make it behave more like other balloon drivers and enable
     some cleanups of generic mm code.

   - A series of fixes to our hardware breakpoint support to properly
     handle unaligned watchpoint addresses.

  Plus a bunch of other smaller improvements, fixes and cleanups.

  Thanks to: Alastair D'Silva, Andrew Donnellan, Aneesh Kumar K.V,
  Anthony Steinhauser, Cédric Le Goater, Chris Packham, Chris Smart,
  Christophe Leroy, Christopher M. Riedl, Christoph Hellwig, Claudio
  Carvalho, Daniel Axtens, David Hildenbrand, Deb McLemore, Diana
  Craciun, Eric Richter, Geert Uytterhoeven, Greg Kroah-Hartman, Greg
  Kurz, Gustavo L. F. Walbon, Hari Bathini, Harish, Jason Yan, Krzysztof
  Kozlowski, Leonardo Bras, Mathieu Malaterre, Mauro S. M. Rodrigues,
  Michal Suchanek, Mimi Zohar, Nathan Chancellor, Nathan Lynch, Nayna
  Jain, Nick Desaulniers, Oliver O'Halloran, Qian Cai, Rasmus Villemoes,
  Ravi Bangoria, Sam Bobroff, Santosh Sivaraj, Scott Wood, Thomas Huth,
  Tyrel Datwyler, Vaibhav Jain, Valentin Longchamp, YueHaibing"

* tag 'powerpc-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (144 commits)
  powerpc/fixmap: fix crash with HIGHMEM
  x86/efi: remove unused variables
  powerpc: Define arch_is_kernel_initmem_freed() for lockdep
  powerpc/prom_init: Use -ffreestanding to avoid a reference to bcmp
  powerpc: Avoid clang warnings around setjmp and longjmp
  powerpc: Don't add -mabi= flags when building with Clang
  powerpc: Fix Kconfig indentation
  powerpc/fixmap: don't clear fixmap area in paging_init()
  selftests/powerpc: spectre_v2 test must be built 64-bit
  powerpc/powernv: Disable native PCIe port management
  powerpc/kexec: Move kexec files into a dedicated subdir.
  powerpc/32: Split kexec low level code out of misc_32.S
  powerpc/sysdev: drop simple gpio
  powerpc/83xx: map IMMR with a BAT.
  powerpc/32s: automatically allocate BAT in setbat()
  powerpc/ioremap: warn on early use of ioremap()
  powerpc: Add support for GENERIC_EARLY_IOREMAP
  powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt()
  powerpc/8xx: use the fixmapped IMMR in cpm_reset()
  powerpc/8xx: add __init to cpm1 init functions
  ...
2019-11-30 14:35:43 -08:00
Christophe Leroy 2807273f5e powerpc/fixmap: fix crash with HIGHMEM
Commit f2bb86937d ("powerpc/fixmap: don't clear fixmap area in
paging_init()") removed the clearing of fixmap area in order to
avoid clearing fixmapped areas set earlier.

However unlike all other users of fixmap which use __set_fixmap(),
HIGHMEM functions directly use __set_pte_at(). This means
the page table must pre-exist, otherwise the following crash
can be encoutered due to the lack of entry in the PGD.

Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=4K MMU=Hash PowerMac
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 5.4.0+ #2528
NIP:  c0144ce8 LR: c0144ccc CTR: 00000080
REGS: ef0b5aa0 TRAP: 0300   Not tainted  (5.4.0+)
MSR:  00009032 <EE,ME,IR,DR,RI>  CR: 44282842  XER: 00000000
DAR: fffdf000 DSISR: 42000000
GPR00: c0144ccc ef0b5b58 ef0b0000 fffdf000 fffdf000 00000000 c0000f7c 00000000
GPR08: c0833000 fffdf000 00000000 ef1c53c9 24042842 00000000 00000000 00000000
GPR16: 00000000 00000000 ef7e7358 effe8160 00000000 c08a9660 c0851644 00000004
GPR24: c08c70a8 00002dc2 00000000 00000001 00000201 effe8160 effe8160 00000000
NIP [c0144ce8] prep_new_page+0x138/0x178
LR [c0144ccc] prep_new_page+0x11c/0x178
Call Trace:
[ef0b5b58] [c0144ccc] prep_new_page+0x11c/0x178 (unreliable)
[ef0b5b88] [c0147218] get_page_from_freelist+0x1fc/0xd88
[ef0b5c38] [c0148328] __alloc_pages_nodemask+0xd4/0xbb4
[ef0b5cf8] [c0142ba8] __vmalloc_node_range+0x1b4/0x2e0
[ef0b5d38] [c0142dd0] vzalloc+0x48/0x58
[ef0b5d58] [c0301c8c] check_partition+0x58/0x244
[ef0b5d78] [c02ffe80] blk_add_partitions+0x44/0x2cc
[ef0b5db8] [c01a32d8] bdev_disk_changed+0x68/0xfc
[ef0b5de8] [c01a4494] __blkdev_get+0x290/0x460
[ef0b5e28] [c02fdd40] __device_add_disk+0x480/0x4d8
[ef0b5e68] [c0810688] brd_init+0xc0/0x188
[ef0b5e88] [c0005194] do_one_initcall+0x40/0x19c
[ef0b5ee8] [c07dd4dc] kernel_init_freeable+0x164/0x230
[ef0b5f28] [c0005408] kernel_init+0x18/0x10c
[ef0b5f38] [c0014274] ret_from_kernel_thread+0x14/0x1c

Partially revert that commit to still clear the fixmap area dedicated
to HIGHMEM.

Fixes: f2bb86937d ("powerpc/fixmap: don't clear fixmap area in paging_init()")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d42fa9747df5afa41e67b08e374c98d3b40529c9.1574927918.git.christophe.leroy@c-s.fr
2019-11-29 22:41:15 +11:00
Christophe Leroy f2bb86937d powerpc/fixmap: don't clear fixmap area in paging_init()
fixmap is intended to map things permanently like the IMMR region on
FSL SOC (8xx, 83xx, ...), so don't clear it when initialising paging()

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/41c99bc06394a6bc2888631cb98a3ed2ae281ddb.1568295907.git.christophe.leroy@c-s.fr
2019-11-25 21:45:43 +11:00
Christoph Hellwig d7293f79ca Merge branch 'for-next/zone-dma' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into dma-mapping-for-next
Pull in a stable branch from the arm64 tree that adds the zone_dma_bits
variable to avoid creating hard to resolve conflicts with that addition.
2019-11-21 18:13:03 +01:00
Christoph Hellwig 56e35f9c5b dma-mapping: drop the dev argument to arch_sync_dma_for_*
These are pure cache maintainance routines, so drop the unused
struct device argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2019-11-20 20:31:38 +01:00
Christophe Leroy cbcaff7d27 powerpc/32s: automatically allocate BAT in setbat()
If no BAT is given to setbat(), select an available BAT.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a212bd36fbd6179e0929b6c727febc35132ac25c.1568665466.git.christophe.leroy@c-s.fr
2019-11-19 19:38:38 +11:00
Christophe Leroy d538aadc27 powerpc/ioremap: warn on early use of ioremap()
Powerpc now has EARLY_IOREMAP.

Next step is to convert all early users of ioremap() to
early_ioremap().

Add a warning to help locate those users.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b4f03a68ee8e68773c8973d74ec35f9c82c72871.1568295907.git.christophe.leroy@c-s.fr
2019-11-19 19:38:38 +11:00
Christophe Leroy a2227a2777 powerpc/32: Don't populate page tables for block mapped pages except on the 8xx.
Commit d2f15e0979 ("powerpc/32: always populate page tables for
Abatron BDI.") wrongly sets page tables for any PPC32 for using BDI,
and does't update them after init (remove RX on init section, set
text and rodata read-only)

Only the 8xx requires page tables to be populated for using the BDI.
They also need to be populated in order to see the mappings in
/sys/kernel/debug/kernel_page_tables

On BOOK3S_32, pages that are not mapped by page tables are mapped
by BATs. The BDI knows BATs and they can be viewed in
/sys/kernel/debug/powerpc/block_address_translation

Only set pagetables for RAM and IMMR on the 8xx and properly update
them at the end of init.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c8610942203e0d93fcb02ad20c57edd3adb4c9d3.1566554029.git.christophe.leroy@c-s.fr
2019-11-18 22:27:52 +11:00
Christophe Leroy 46ddcb3950 powerpc/mm: Show if a bad page fault on data is read or write.
DSISR (or ESR on some CPUs) has a bit to tell if the fault is due to a
read or a write.

Display it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4f88d7e6fda53b5f80a71040ab400242f6c8cb93.1566400889.git.christophe.leroy@c-s.fr
2019-11-18 22:27:51 +11:00
Michael Ellerman 3df191118b Merge branch 'topic/kaslr-book3e32' into next
This is a slight rebase of Scott's next branch, which contained the
KASLR support for book3e 32-bit, to squash in a couple of small fixes.

See the	original pull request:
  https://lore.kernel.org/r/20191022232155.GA26174@home.buserror.net
2019-11-14 19:23:33 +11:00
Jason Yan 8c2ae87be5 powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter
One may want to disable kaslr when boot, so provide a cmdline parameter
'nokaslr' to support this.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13 19:27:47 +11:00
Jason Yan b396097200 powerpc/fsl_booke/kaslr: clear the original kernel if randomized
The original kernel still exists in the memory, clear it now.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13 19:27:44 +11:00
Jason Yan 6a38ea1d7b powerpc/fsl_booke/32: randomize the kernel image offset
After we have the basic support of relocate the kernel in some
appropriate place, we can start to randomize the offset now.

Entropy is derived from the banner and timer, which will change every
build and boot. This not so much safe so additionally the bootloader may
pass entropy via the /chosen/kaslr-seed node in device tree.

We will use the first 512M of the low memory to randomize the kernel
image. The memory will be split in 64M zones. We will use the lower 8
bit of the entropy to decide the index of the 64M zone. Then we chose a
16K aligned offset inside the 64M zone to put the kernel in.

We also check if we will overlap with some areas like the dtb area, the
initrd area or the crashkernel area. If we cannot find a proper area,
kaslr will be disabled and boot from the original kernel.

Some pieces of code are derived from arch/x86/boot/compressed/kaslr.c or
arch/arm64/kernel/kaslr.c such as rotate_xor(). Credit goes to Kees and
Ard.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13 19:27:41 +11:00
Jason Yan 2b0e86cc5d powerpc/fsl_booke/32: implement KASLR infrastructure
This patch add support to boot kernel from places other than KERNELBASE.
Since CONFIG_RELOCATABLE has already supported, what we need to do is
map or copy kernel to a proper place and relocate. Freescale Book-E
parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1
entries are not suitable to map the kernel directly in a randomized
region, so we chose to copy the kernel to a proper place and restart to
relocate.

The offset of the kernel was not randomized yet(a fixed 64M is set). We
will randomize it in the next patch.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
[mpe: Use PTRRELOC() in early_init()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13 19:27:40 +11:00
Jason Yan c061b38a3e powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper
Add a new helper reloc_kernel_entry() to jump back to the start of the
new kernel. After we put the new kernel in a randomized place we can use
this new helper to enter the kernel and begin to relocate again.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13 19:27:37 +11:00
Jason Yan aa1d2090e6 powerpc/fsl_booke/32: introduce create_kaslr_tlb_entry() helper
Add a new helper create_kaslr_tlb_entry() to create a tlb entry by the
virtual and physical address. This is a preparation to support boot kernel
at a randomized address.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13 19:27:34 +11:00
Jason Yan 39f4b7bf75 powerpc: introduce kernstart_virt_addr to store the kernel base
Now the kernel base is a fixed value - KERNELBASE. To support KASLR, we
need a variable to store the kernel base.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13 19:27:32 +11:00
Jason Yan 4ed47dbefa powerpc: move memstart_addr and kernstart_addr to init-common.c
These two variables are both defined in init_32.c and init_64.c. Move
them to init-common.c and make them __ro_after_init.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-11-13 19:27:28 +11:00
Alastair D'Silva ea458effa8 powerpc: Don't flush caches when adding memory
This operation takes a significant amount of time when hotplugging
large amounts of memory (~50 seconds with 890GB of persistent memory).

This was orignally in commit fb5924fddf
("powerpc/mm: Flush cache on memory hot(un)plug") to support memtrace,
but the flush on add is not needed as it is flushed on remove.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-7-alastair@au1.ibm.com
2019-11-07 23:35:41 +11:00
Alastair D'Silva 076265907c powerpc: Chunk calls to flush_dcache_range in arch_*_memory
When presented with large amounts of memory being hotplugged
(in my test case, ~890GB), the call to flush_dcache_range takes
a while (~50 seconds), triggering RCU stalls.

This patch breaks up the call into 1GB chunks, calling
cond_resched() inbetween to allow the scheduler to run.

Fixes: fb5924fddf ("powerpc/mm: Flush cache on memory hot(un)plug")
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-6-alastair@au1.ibm.com
2019-11-07 23:35:41 +11:00
Alastair D'Silva 23eb7f560a powerpc: Convert flush_icache_range & friends to C
Similar to commit 22e9c88d48
("powerpc/64: reuse PPC32 static inline flush_dcache_range()")
this patch converts the following ASM symbols to C:
    flush_icache_range()
    __flush_dcache_icache()
    __flush_dcache_icache_phys()

This was done as we discovered a long-standing bug where the length of the
range was truncated due to using a 32 bit shift instead of a 64 bit one.

By converting these functions to C, it becomes easier to maintain.

flush_dcache_icache_phys() retains a critical assembler section as we must
ensure there are no memory accesses while the data MMU is disabled
(authored by Christophe Leroy). Since this has no external callers, it has
also been made static, allowing the compiler to inline it within
flush_dcache_icache_page().

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[mpe: Minor fixups, don't export __flush_dcache_icache()]
Link: https://lore.kernel.org/r/20191104023305.9581-5-alastair@au1.ibm.com
2019-11-07 23:35:37 +11:00
Aneesh Kumar K.V 16f6b67cf0 powerpc/book3s64/hash: Add cond_resched to avoid soft lockup warning
With large memory (8TB and more) hotplug, we can get soft lockup
warnings as below. These were caused by a long loop without any
explicit cond_resched which is a problem for !PREEMPT kernels.

Avoid this using cond_resched() while inserting hash page table
entries. We already do similar cond_resched() in __add_pages(), see
commit f64ac5e6e3 ("mm, memory_hotplug: add scheduling point to
__add_pages").

  rcu:     3-....: (24002 ticks this GP) idle=13e/1/0x4000000000000002 softirq=722/722 fqs=12001
   (t=24003 jiffies g=4285 q=2002)
  NMI backtrace for cpu 3
  CPU: 3 PID: 3870 Comm: ndctl Not tainted 5.3.0-197.18-default+ #2
  Call Trace:
    dump_stack+0xb0/0xf4 (unreliable)
    nmi_cpu_backtrace+0x124/0x130
    nmi_trigger_cpumask_backtrace+0x1ac/0x1f0
    arch_trigger_cpumask_backtrace+0x28/0x3c
    rcu_dump_cpu_stacks+0xf8/0x154
    rcu_sched_clock_irq+0x878/0xb40
    update_process_times+0x48/0x90
    tick_sched_handle.isra.16+0x4c/0x80
    tick_sched_timer+0x68/0xe0
    __hrtimer_run_queues+0x180/0x430
    hrtimer_interrupt+0x110/0x300
    timer_interrupt+0x108/0x2f0
    decrementer_common+0x114/0x120
  --- interrupt: 901 at arch_add_memory+0xc0/0x130
      LR = arch_add_memory+0x74/0x130
    memremap_pages+0x494/0x650
    devm_memremap_pages+0x3c/0xa0
    pmem_attach_disk+0x188/0x750
    nvdimm_bus_probe+0xac/0x2c0
    really_probe+0x148/0x570
    driver_probe_device+0x19c/0x1d0
    device_driver_attach+0xcc/0x100
    bind_store+0x134/0x1c0
    drv_attr_store+0x44/0x60
    sysfs_kf_write+0x64/0x90
    kernfs_fop_write+0x1a0/0x270
    __vfs_write+0x3c/0x70
    vfs_write+0xd0/0x260
    ksys_write+0xdc/0x130
    system_call+0x5c/0x68

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191001084656.31277-1-aneesh.kumar@linux.ibm.com
2019-11-05 22:24:57 +11:00
Aneesh Kumar K.V 864edb758c powerpc/mm/book3s64/radix: Flush the full mm even when need_flush_all is set
With the previous patch, we should now not be using need_flush_all for
powerpc. But then make sure we force a PID tlbie flush with RIC=2 if
we ever find need_flush_all set. Also don't reset it after a mmu
gather flush.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024075801.22434-3-aneesh.kumar@linux.ibm.com
2019-11-05 22:24:18 +11:00
Aneesh Kumar K.V 52162ec784 powerpc/mm/book3s64/radix: Use freed_tables instead of need_flush_all
With commit 22a61c3c4f ("asm-generic/tlb: Track freeing of
page-table directories in struct mmu_gather") we now track whether we
freed page table in mmu_gather. Use that to decide whether to flush
Page Walk Cache.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024075801.22434-2-aneesh.kumar@linux.ibm.com
2019-11-05 22:23:55 +11:00
Aneesh Kumar K.V a42d6ba8c5 powerpc/mm/book3s64/radix: Remove unused code.
mm_tlb_flush_nested change was added in the mmu gather tlb flush to
handle the case of parallel pte invalidate happening with mmap_sem
held in read mode. This fix was done by commit
02390f66bd ("powerpc/64s/radix: Fix MADV_[FREE|DONTNEED] TLB flush
miss problem with THP") and the problem is explained in detail in
commit 99baac21e4 ("mm: fix MADV_[FREE|DONTNEED] TLB flush miss
problem")

This was later updated by commit 7a30df49f6 ("mm: mmu_gather: remove
__tlb_reset_range() for force flush") to do a full mm flush rather
than a range flush. By commit dd2283f260 ("mm: mmap: zap pages with
read mmap_sem in munmap") we are also now allowing a page table free
in mmap_sem read mode which means we should do a PWC flush too. Our
current full mm flush imply a PWC flush.

With all the above change the mm_tlb_flush_nested(mm) branch in
radix__tlb_flush will never be taken because for the nested case we
would have taken the if (tlb->fullmm) branch. This patch removes the
unused code. Also, remove the gflush change in
__radix__flush_tlb_range that was added to handle the range tlb flush
code. We only check for THP there because hugetlb is flushed via a
different code path where page size is explicitly specified.

This is a partial revert of commit 02390f66bd ("powerpc/64s/radix:
Fix MADV_[FREE|DONTNEED] TLB flush miss problem with THP")

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024075801.22434-1-aneesh.kumar@linux.ibm.com
2019-11-05 22:23:17 +11:00
Nicolas Saenz Julienne 8b5369ea58 dma/direct: turn ARCH_ZONE_DMA_BITS into a variable
Some architectures, notably ARM, are interested in tweaking this
depending on their runtime DMA addressing limitations.

Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-11-01 09:41:18 +00:00
Aneesh Kumar K.V d78d5dace5 powerpc/book3s64/hash: Use secondary hash for bolted mapping if the primary is full
With bolted hash page table entry, kernel currently only use primary hash group
when inserting the hash page table entry. In the rare case where kernel find all the
8 primary hash slot occupied by bolted entries, this can result in hash page
table insert failure for bolted entries. Avoid this by using the secondary hash
group.

This is different from what kernel does for the non-bolted mapping. With
non-bolted entries kernel will try secondary before removing an existing entry
from hash page table group. With bolted prefer primary hash group and hence
try to insert the page table entry by removing a slot from primary before trying
the secondary hash group.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024093542.29777-3-aneesh.kumar@linux.ibm.com
2019-10-28 21:54:16 +11:00
Aneesh Kumar K.V 75838a3290 powerpc/pseries: Don't fail hash page table insert for bolted mapping
If the hypervisor returned H_PTEG_FULL for H_ENTER hcall, retry a hash page table
insert by removing a random entry from the group.

After some runtime, it is very well possible to find all the 8 hash page table
entry slot in the hpte group used for mapping. Don't fail a bolted entry insert
in that case. With Storage class memory a user can find this error easily since
a namespace enable/disable is equivalent to memory add/remove.

This results in failures as reported below:

$ ndctl create-namespace -r region1 -t pmem -m devdax -a 65536 -s 100M
libndctl: ndctl_dax_enable: dax1.3: failed to enable
  Error: namespace1.2: failed to enable

failed to create namespace: No such device or address

In kernel log we find the details as below:

Unable to create mapping for hot added memory 0xc000042006000000..0xc00004200d000000: -1
dax_pmem: probe of dax1.3 failed with error -14

This indicates that we failed to create a bolted hash table entry for direct-map
address backing the namespace.

We also observe failures such that not all namespaces will be enabled with
ndctl enable-namespace all command.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024093542.29777-2-aneesh.kumar@linux.ibm.com
2019-10-28 21:54:16 +11:00
Aneesh Kumar K.V 5f5d6e40a0 powerpc/nvdimm: Update vmemmap_populated to check sub-section range
With commit: 7cc7867fb0 ("mm/devm_memremap_pages: enable sub-section remap")
pmem namespaces are remapped in 2M chunks. On architectures like ppc64 we
can map the memmap area using 16MB hugepage size and that can cover
a memory range of 16G.

While enabling new pmem namespaces, since memory is added in sub-section chunks,
before creating a new memmap mapping, kernel should check whether there is an
existing memmap mapping covering the new pmem namespace. Currently, this is
validated by checking whether the section covering the range is already
initialized or not. Considering there can be multiple namespaces in the same
section this can result in wrong validation. Update this to check for
sub-sections in the range. This is done by checking for all pfns in the range we
are mapping.

We could optimize this by checking only just one pfn in each sub-section. But
since this is not fast-path we keep this simple.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190917123851.22553-1-aneesh.kumar@linux.ibm.com
2019-10-28 21:54:15 +11:00
Qian Cai 29674a1c71 powerpc/pkeys: remove unused pkey_allows_readwrite
pkey_allows_readwrite() was first introduced in the commit 5586cf61e1
("powerpc: introduce execute-only pkey"), but the usage was removed
entirely in the commit a4fcc877d4 ("powerpc/pkeys: Preallocate
execute-only key").

Found by the "-Wunused-function" compiler warning flag.

Fixes: a4fcc877d4 ("powerpc/pkeys: Preallocate execute-only key")
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1568733750-14580-1-git-send-email-cai@lca.pw
2019-10-11 19:34:10 +11:00
Linus Torvalds a3c0e7b1fe libnvdimm fixes v5.4-rc1
- Complete the reworks to interoperate with powerpc dynamic huge page sizes
 
 - Fix a crash due to missed accounting for the powerpc 'struct
   page'-memmap mapping granularity.
 
 - Fix badblock initialization for volatile (DRAM emulated) pmem ranges.
 
 - Stop triggering request_key() notifications to userspace when
   NVDIMM-security is disabled / not present.
 
 - Miscellaneous small fixups.
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJdkAprAAoJEB7SkWpmfYgCjXoQAIwJE1VzNP1V+ARxfs1rTGVz
 pbNJiBnj4gxDaCkcKoatiadRkytUxeUNEcPslEKsfoNinXYqkpjMQoWm2VpILOMU
 nY+SvIudGRnuesq2/Y+CP8zrX6rV4eBDfHK05RN/Zp1IlW7pTDItUx8mJ7glmDwG
 PW0vkvK7yZ+dRFnpQ7QFjhA0Q3oudO5YcTVBDK5YYtDGlv69xfXqc9LW8SszJ1kU
 rhCIT1kdoL5of0TIgG5pTfmggPSQ9y1xPsKjllOHNa3m50eGOkkQLELOVzQb1frW
 cjAsPLjRDSzvdHHSLyu0Is04Q5JU2CucxHl2SXGHiOt5tigH8dk5XFxWt0Pc8EXx
 acYYiBqUXC3MomSYWeLK4BdO2cRTqcPPXgJYAqXblqr+/0ys+rFepjw+j8JkiLZa
 5UCC30l1GXEpw9u6gdCMqvvHN2gHvDB0BV82Sx8wTewJpeL18wCUJoKVuFmpsHko
 p1cCe7St1TzcK3eO+xfeW1rxNrcXUpKVYXVa/WOJW0vwErqAZ6YCdNuyJHocZzXn
 vNyIQmVDOlubsgBAI2ExxeZO6xc8UIwLhLg7XEJ0mg3k6UXA8HZxH2B2THJk1BSF
 RppodkYiMknh11sqgpGp+Hz5XSEg/jvmCdL/qRDGAwhsFhFaxDH37Kg4Qncj2/dg
 uDvDHXNCjbGpzCo3tyNx
 =Z6Fa
 -----END PGP SIGNATURE-----

Merge tag 'libnvdimm-fixes-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

More libnvdimm updates from Dan Williams:

 - Complete the reworks to interoperate with powerpc dynamic huge page
   sizes

 - Fix a crash due to missed accounting for the powerpc 'struct
   page'-memmap mapping granularity

 - Fix badblock initialization for volatile (DRAM emulated) pmem ranges

 - Stop triggering request_key() notifications to userspace when
   NVDIMM-security is disabled / not present

 - Miscellaneous small fixups

* tag 'libnvdimm-fixes-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm/region: Enable MAP_SYNC for volatile regions
  libnvdimm: prevent nvdimm from requesting key when security is disabled
  libnvdimm/region: Initialize bad block for volatile namespaces
  libnvdimm/nfit_test: Fix acpi_handle redefinition
  libnvdimm/altmap: Track namespace boundaries in altmap
  libnvdimm: Fix endian conversion issues 
  libnvdimm/dax: Pick the right alignment default when creating dax devices
  powerpc/book3s64: Export has_transparent_hugepage() related functions.
2019-09-29 10:33:41 -07:00
Linus Torvalds a2953204b5 powerpc fixes for 5.4 #2
An assortment of fixes that were either missed by me, or didn't arrive quite in
 time for the first v5.4 pull.
 
 Most notable is a fix for an issue with tlbie (broadcast TLB invalidation) on
 Power9, when using the Radix MMU. The tlbie can race with an mtpid (move to PID
 register, essentially MMU context switch) on another thread of the core, which
 can cause stores to continue to go to a page after it's unmapped.
 
 A fix in our KVM code to add a missing barrier, the lack of which has been
 observed to cause missed IPIs and subsequently stuck CPUs in the host.
 
 A change to the way we initialise PCR (Processor Compatibility Register) to make
 it forward compatible with future CPUs.
 
 On some older PowerVM systems our H_BLOCK_REMOVE support could oops, fix it to
 detect such systems and fallback to the old invalidation method.
 
 A fix for an oops seen on some machines when using KASAN on 32-bit.
 
 A handful of other minor fixes, and two new selftests.
 
 Thanks to:
   Alistair Popple, Aneesh Kumar K.V, Christophe Leroy, Gustavo Romero, Joel
   Stanley, Jordan Niethe, Laurent Dufour, Michael Roth, Oliver O'Halloran.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCAAxFiEEJFGtCPCthwEv2Y/bUevqPMjhpYAFAl2PRGITHG1wZUBlbGxl
 cm1hbi5pZC5hdQAKCRBR6+o8yOGlgClRD/9jKIT6GjVpRMc+Dg9zHB5/Pir7gePk
 ztXKI+u15GrrXgjtWEZ1PaaXvtNIfs/IZHDQm5gyJjiBAKcGl2v+9ETaMzO5sjZ7
 GSe1F8VX/MwzRnET8Jph8w/b0cy0Q8xndkEOjcJqJ7+TF+SSWqmJEdmBfkU23jWD
 B3kW4W1x2xt/XGsX25l1HpUgpcJqzukCeYUSCdqUu2j+sXAEZmfgTRG8uD4HffzZ
 3As76TrBiJsDnkyH0qi2G1BuLXrQbAMdjTeSGi+cb0gTIunCr190gI4+Tjdu2/z7
 ywWR2ZUkueCNDcLsqXaqpZx50utPJ44//uY750sk72vixJJOVuOWM6+5HKVW83se
 /v0zkOcI9+ywNHe0vLfP3Jm/OMMHYxkIwz6kVu2NSR6sE79B9AZpBFU+Nynq7kKl
 +Hc6md/HATvR+NK6LtQKtEGydRhvxU5n3KBmjq3SQj+B/ZlU6IdgerfhUWrNvg0B
 zzHeT35X6UBpswonhkQLgqJuaWpkClK9wsUy85MuA7aub1EP8S6/X7paKoiOtAHK
 NjlXM2JYV5OKwhjGgdCiI94Bdune7yudKPdsXV3Gr8Iw7wf2bQk1p7VH+LcruyE9
 YJdXwCgN0PaoFUQh3AR4CqzzFwqDya8FQqdkFN3kqhRLVGAMq/PsV8/Tn+myTgQP
 rZnWnbfZh9BMjw==
 =dF42
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "An assortment of fixes that were either missed by me, or didn't arrive
  quite in time for the first v5.4 pull.

   - Most notable is a fix for an issue with tlbie (broadcast TLB
     invalidation) on Power9, when using the Radix MMU. The tlbie can
     race with an mtpid (move to PID register, essentially MMU context
     switch) on another thread of the core, which can cause stores to
     continue to go to a page after it's unmapped.

   - A fix in our KVM code to add a missing barrier, the lack of which
     has been observed to cause missed IPIs and subsequently stuck CPUs
     in the host.

   - A change to the way we initialise PCR (Processor Compatibility
     Register) to make it forward compatible with future CPUs.

   - On some older PowerVM systems our H_BLOCK_REMOVE support could
     oops, fix it to detect such systems and fallback to the old
     invalidation method.

   - A fix for an oops seen on some machines when using KASAN on 32-bit.

   - A handful of other minor fixes, and two new selftests.

  Thanks to: Alistair Popple, Aneesh Kumar K.V, Christophe Leroy,
  Gustavo Romero, Joel Stanley, Jordan Niethe, Laurent Dufour, Michael
  Roth, Oliver O'Halloran"

* tag 'powerpc-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/eeh: Fix eeh eeh_debugfs_break_device() with SRIOV devices
  powerpc/nvdimm: use H_SCM_QUERY hcall on H_OVERLAP error
  powerpc/nvdimm: Use HCALL error as the return value
  selftests/powerpc: Add test case for tlbie vs mtpidr ordering issue
  powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9
  powerpc/book3s64/radix: Rename CPU_FTR_P9_TLBIE_BUG feature flag
  powerpc/book3s64/mm: Don't do tlbie fixup for some hardware revisions
  powerpc/pseries: Call H_BLOCK_REMOVE when supported
  powerpc/pseries: Read TLB Block Invalidate Characteristics
  KVM: PPC: Book3S HV: use smp_mb() when setting/clearing host_ipi flag
  powerpc/mm: Fix an Oops in kasan_mmu_init()
  powerpc/mm: Add a helper to select PAGE_KERNEL_RO or PAGE_READONLY
  powerpc/64s: Set reserved PCR bits
  powerpc: Fix definition of PCR bits to work with old binutils
  powerpc/book3s64/radix: Remove WARN_ON in destroy_context()
  powerpc/tm: Add tm-poison test
2019-09-28 13:43:00 -07:00
Mark Rutland b4ed71f557 mm: treewide: clarify pgtable_page_{ctor,dtor}() naming
The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-26 10:10:44 -07:00
Kefeng Wang 9ef258bad7 thp: update split_huge_page_pmd() comment
According to 78ddc53473 ("thp: rename split_huge_page_pmd() to
split_huge_pmd()"), update related comment.

Link: http://lkml.kernel.org/r/20190731033406.185285-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:10 -07:00
Matthew Wilcox (Oracle) d8c6546b1a mm: introduce compound_nr()
Replace 1 << compound_order(page) with compound_nr(page).  Minor
improvements in readability.

Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:08 -07:00
Matthew Wilcox (Oracle) 94ad933810 mm: introduce page_shift()
Replace PAGE_SHIFT + compound_order(page) with the new page_shift()
function.  Minor improvements in readability.

[akpm@linux-foundation.org: fix build in tce_page_is_contained()]
  Link: http://lkml.kernel.org/r/201907241853.yNQTrJWd%25lkp@intel.com
Link: http://lkml.kernel.org/r/20190721104612.19120-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:08 -07:00
Aneesh Kumar K.V cf387d9644 libnvdimm/altmap: Track namespace boundaries in altmap
With PFN_MODE_PMEM namespace, the memmap area is allocated from the device
area. Some architectures map the memmap area with large page size. On
architectures like ppc64, 16MB page for memap mapping can map 262144 pfns.
This maps a namespace size of 16G.

When populating memmap region with 16MB page from the device area,
make sure the allocated space is not used to map resources outside this
namespace. Such usage of device area will prevent a namespace destroy.

Add resource end pnf in altmap and use that to check if the memmap area
allocation can map pfn outside the namespace. On ppc64 in such case we fallback
to allocation from memory.

This fix kernel crash reported below:

[  132.034989] WARNING: CPU: 13 PID: 13719 at mm/memremap.c:133 devm_memremap_pages_release+0x2d8/0x2e0
[  133.464754] BUG: Unable to handle kernel data access at 0xc00c00010b204000
[  133.464760] Faulting instruction address: 0xc00000000007580c
[  133.464766] Oops: Kernel access of bad area, sig: 11 [#1]
[  133.464771] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
.....
[  133.464901] NIP [c00000000007580c] vmemmap_free+0x2ac/0x3d0
[  133.464906] LR [c0000000000757f8] vmemmap_free+0x298/0x3d0
[  133.464910] Call Trace:
[  133.464914] [c000007cbfd0f7b0] [c0000000000757f8] vmemmap_free+0x298/0x3d0 (unreliable)
[  133.464921] [c000007cbfd0f8d0] [c000000000370a44] section_deactivate+0x1a4/0x240
[  133.464928] [c000007cbfd0f980] [c000000000386270] __remove_pages+0x3a0/0x590
[  133.464935] [c000007cbfd0fa50] [c000000000074158] arch_remove_memory+0x88/0x160
[  133.464942] [c000007cbfd0fae0] [c0000000003be8c0] devm_memremap_pages_release+0x150/0x2e0
[  133.464949] [c000007cbfd0fb70] [c000000000738ea0] devm_action_release+0x30/0x50
[  133.464955] [c000007cbfd0fb90] [c00000000073a5a4] release_nodes+0x344/0x400
[  133.464961] [c000007cbfd0fc40] [c00000000073378c] device_release_driver_internal+0x15c/0x250
[  133.464968] [c000007cbfd0fc80] [c00000000072fd14] unbind_store+0x104/0x110
[  133.464973] [c000007cbfd0fcd0] [c00000000072ee24] drv_attr_store+0x44/0x70
[  133.464981] [c000007cbfd0fcf0] [c0000000004a32bc] sysfs_kf_write+0x6c/0xa0
[  133.464987] [c000007cbfd0fd10] [c0000000004a1dfc] kernfs_fop_write+0x17c/0x250
[  133.464993] [c000007cbfd0fd60] [c0000000003c348c] __vfs_write+0x3c/0x70
[  133.464999] [c000007cbfd0fd80] [c0000000003c75d0] vfs_write+0xd0/0x250

djbw: Aneesh notes that this crash can likely be triggered in any kernel that
supports 'papr_scm', so flagging that commit for -stable consideration.

Fixes: b5beae5e22 ("powerpc/pseries: Add driver for PAPR SCM regions")
Cc: <stable@vger.kernel.org>
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>
Tested-by: Santosh Sivaraj <santosh@fossix.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Link: https://lore.kernel.org/r/20190910062826.10041-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-09-24 10:24:12 -07:00
Aneesh Kumar K.V a6f197f889 powerpc/book3s64: Export has_transparent_hugepage() related functions.
In later patch, we want to use hash_transparent_hugepage() in a kernel module.
Export two related functions.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20190924042440.27946-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-09-24 10:22:29 -07:00
Aneesh Kumar K.V 047e6575ae powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9
On POWER9, under some circumstances, a broadcast TLB invalidation will
fail to invalidate the ERAT cache on some threads when there are
parallel mtpidr/mtlpidr happening on other threads of the same core.
This can cause stores to continue to go to a page after it's unmapped.

The workaround is to force an ERAT flush using PID=0 or LPID=0 tlbie
flush. This additional TLB flush will cause the ERAT cache
invalidation. Since we are using PID=0 or LPID=0, we don't get
filtered out by the TLB snoop filtering logic.

We need to still follow this up with another tlbie to take care of
store vs tlbie ordering issue explained in commit:
a5d4b5891c ("powerpc/mm: Fixup tlbie vs store ordering issue on
POWER9"). The presence of ERAT cache implies we can still get new
stores and they may miss store queue marking flush.

Cc: stable@vger.kernel.org
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190924035254.24612-3-aneesh.kumar@linux.ibm.com
2019-09-24 20:58:55 +10:00
Aneesh Kumar K.V 09ce98cacd powerpc/book3s64/radix: Rename CPU_FTR_P9_TLBIE_BUG feature flag
Rename the #define to indicate this is related to store vs tlbie
ordering issue. In the next patch, we will be adding another feature
flag that is used to handles ERAT flush vs tlbie ordering issue.

Fixes: a5d4b5891c ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190924035254.24612-2-aneesh.kumar@linux.ibm.com
2019-09-24 20:58:47 +10:00
Linus Torvalds 84da111de0 hmm related patches for 5.4
This is more cleanup and consolidation of the hmm APIs and the very
 strongly related mmu_notifier interfaces. Many places across the tree
 using these interfaces are touched in the process. Beyond that a cleanup
 to the page walker API and a few memremap related changes round out the
 series:
 
 - General improvement of hmm_range_fault() and related APIs, more
   documentation, bug fixes from testing, API simplification &
   consolidation, and unused API removal
 
 - Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE, and
   make them internal kconfig selects
 
 - Hoist a lot of code related to mmu notifier attachment out of drivers by
   using a refcount get/put attachment idiom and remove the convoluted
   mmu_notifier_unregister_no_release() and related APIs.
 
 - General API improvement for the migrate_vma API and revision of its only
   user in nouveau
 
 - Annotate mmu_notifiers with lockdep and sleeping region debugging
 
 Two series unrelated to HMM or mmu_notifiers came along due to
 dependencies:
 
 - Allow pagemap's memremap_pages family of APIs to work without providing
   a struct device
 
 - Make walk_page_range() and related use a constant structure for function
   pointers
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEfB7FMLh+8QxL+6i3OG33FX4gmxoFAl1/nnkACgkQOG33FX4g
 mxqaRg//c6FqowV1pQlLutvAOAgMdpzfZ9eaaDKngy9RVQxz+k/MmJrdRH/p/mMA
 Pq93A1XfwtraGKErHegFXGEDk4XhOustVAVFwvjyXO41dTUdoFVUkti6ftbrl/rS
 6CT+X90jlvrwdRY7QBeuo7lxx7z8Qkqbk1O1kc1IOracjKfNJS+y6LTamy6weM3g
 tIMHI65PkxpRzN36DV9uCN5dMwFzJ73DWHp1b0acnDIigkl6u5zp6orAJVWRjyQX
 nmEd3/IOvdxaubAoAvboNS5CyVb4yS9xshWWMbH6AulKJv3Glca1Aa7QuSpBoN8v
 wy4c9+umzqRgzgUJUe1xwN9P49oBNhJpgBSu8MUlgBA4IOc3rDl/Tw0b5KCFVfkH
 yHkp8n6MP8VsRrzXTC6Kx0vdjIkAO8SUeylVJczAcVSyHIo6/JUJCVDeFLSTVymh
 EGWJ7zX2iRhUbssJ6/izQTTQyCH3YIyZ5QtqByWuX2U7ZrfkqS3/EnBW1Q+j+gPF
 Z2yW8iT6k0iENw6s8psE9czexuywa/Lttz94IyNlOQ8rJTiQqB9wLaAvg9hvUk7a
 kuspL+JGIZkrL3ouCeO/VA6xnaP+Q7nR8geWBRb8zKGHmtWrb5Gwmt6t+vTnCC2l
 olIDebrnnxwfBQhEJ5219W+M1pBpjiTpqK/UdBd92A4+sOOhOD0=
 =FRGg
 -----END PGP SIGNATURE-----

Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull hmm updates from Jason Gunthorpe:
 "This is more cleanup and consolidation of the hmm APIs and the very
  strongly related mmu_notifier interfaces. Many places across the tree
  using these interfaces are touched in the process. Beyond that a
  cleanup to the page walker API and a few memremap related changes
  round out the series:

   - General improvement of hmm_range_fault() and related APIs, more
     documentation, bug fixes from testing, API simplification &
     consolidation, and unused API removal

   - Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE,
     and make them internal kconfig selects

   - Hoist a lot of code related to mmu notifier attachment out of
     drivers by using a refcount get/put attachment idiom and remove the
     convoluted mmu_notifier_unregister_no_release() and related APIs.

   - General API improvement for the migrate_vma API and revision of its
     only user in nouveau

   - Annotate mmu_notifiers with lockdep and sleeping region debugging

  Two series unrelated to HMM or mmu_notifiers came along due to
  dependencies:

   - Allow pagemap's memremap_pages family of APIs to work without
     providing a struct device

   - Make walk_page_range() and related use a constant structure for
     function pointers"

* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (75 commits)
  libnvdimm: Enable unit test infrastructure compile checks
  mm, notifier: Catch sleeping/blocking for !blockable
  kernel.h: Add non_block_start/end()
  drm/radeon: guard against calling an unpaired radeon_mn_unregister()
  csky: add missing brackets in a macro for tlb.h
  pagewalk: use lockdep_assert_held for locking validation
  pagewalk: separate function pointers from iterator data
  mm: split out a new pagewalk.h header from mm.h
  mm/mmu_notifiers: annotate with might_sleep()
  mm/mmu_notifiers: prime lockdep
  mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end
  mm/mmu_notifiers: remove the __mmu_notifier_invalidate_range_start/end exports
  mm/hmm: hmm_range_fault() infinite loop
  mm/hmm: hmm_range_fault() NULL pointer bug
  mm/hmm: fix hmm_range_fault()'s handling of swapped out pages
  mm/mmu_notifiers: remove unregister_no_release
  RDMA/odp: remove ib_ucontext from ib_umem
  RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm'
  RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr
  RDMA/mlx5: Use ib_umem_start instead of umem.address
  ...
2019-09-21 10:07:42 -07:00
Christophe Leroy cbd18991e2 powerpc/mm: Fix an Oops in kasan_mmu_init()
Uncompressing Kernel Image ... OK
   Loading Device Tree to 01ff7000, end 01fff74f ... OK
[    0.000000] printk: bootconsole [udbg0] enabled
[    0.000000] BUG: Unable to handle kernel data access at 0xf818c000
[    0.000000] Faulting instruction address: 0xc0013c7c
[    0.000000] Thread overran stack, or stack corrupted
[    0.000000] Oops: Kernel access of bad area, sig: 11 [#1]
[    0.000000] BE PAGE_SIZE=16K PREEMPT
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.3.0-rc4-s3k-dev-00743-g5abe4a3e8fd3-dirty #2080
[    0.000000] NIP:  c0013c7c LR: c0013310 CTR: 00000000
[    0.000000] REGS: c0c5ff38 TRAP: 0300   Not tainted  (5.3.0-rc4-s3k-dev-00743-g5abe4a3e8fd3-dirty)
[    0.000000] MSR:  00001032 <ME,IR,DR,RI>  CR: 99033955  XER: 80002100
[    0.000000] DAR: f818c000 DSISR: 82000000
[    0.000000] GPR00: c0013310 c0c5fff0 c0ad6ac0 c0c600c0 f818c031 82000000 00000000 ffffffff
[    0.000000] GPR08: 00000000 f1f1f1f1 c0013c2c c0013304 99033955 00400008 00000000 07ff9598
[    0.000000] GPR16: 00000000 07ffb94c 00000000 00000000 00000000 00000000 00000000 f818cfb2
[    0.000000] GPR24: 00000000 00000000 00001000 ffffffff 00000000 c07dbf80 00000000 f818c000
[    0.000000] NIP [c0013c7c] do_page_fault+0x50/0x904
[    0.000000] LR [c0013310] handle_page_fault+0xc/0x38
[    0.000000] Call Trace:
[    0.000000] Instruction dump:
[    0.000000] be010080 91410014 553fe8fe 3d40c001 3d20f1f1 7d800026 394a3c2c 3fffe000
[    0.000000] 6129f1f1 900100c4 9181007c 91410018 <913f0000> 3d2001f4 6129f4f4 913f0004

Don't map the early shadow page read-only yet when creating the new
page tables for the real shadow memory, otherwise the memblock
allocations that immediately follows to create the real shadow pages
that are about to replace the early shadow page trigger a page fault
if they fall into the region being worked on at the moment.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Fixes: 2edb16efc8 ("powerpc/32: Add KASAN support")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fe86886fb8db44360417cee0dc515ad47ca6ef72.1566382750.git.christophe.leroy@c-s.fr
2019-09-21 08:36:53 +10:00
Christophe Leroy 4c0f5d1eb4 powerpc/mm: Add a helper to select PAGE_KERNEL_RO or PAGE_READONLY
In a couple of places there is a need to select whether read-only
protection of shadow pages is performed with PAGE_KERNEL_RO or with
PAGE_READONLY.

Add a helper to avoid duplicating the choice.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9f33f44b9cd741c4a02b3dce7b8ef9438fe2cd2a.1566382750.git.christophe.leroy@c-s.fr
2019-09-21 08:36:53 +10:00
Aneesh Kumar K.V 7aec584eaf powerpc/book3s64/radix: Remove WARN_ON in destroy_context()
On failed task initialization due to memory allocation failures, we can
call into destroy_context() with process_tb entry already populated.
This patch forces the process_tb entry to zero in destroy_context().
With this patch, we lose the ability to track if we are destroying a
context without flushing the process table entry.

  WARNING: CPU: 4 PID: 6368 at arch/powerpc/mm/mmu_context_book3s64.c:246 destroy_context+0x58/0x340
  NIP [c0000000000875f8] destroy_context+0x58/0x340
  LR [c00000000013da18] __mmdrop+0x78/0x270
  Call Trace:
  [c000000f7db77c80] [c00000000013da18] __mmdrop+0x78/0x270
  [c000000f7db77cf0] [c0000000004d6a34] __do_execve_file.isra.13+0xbd4/0x1000
  [c000000f7db77e00] [c0000000004d7428] sys_execve+0x58/0x70
  [c000000f7db77e30] [c00000000000b388] system_call+0x5c/0x70

Reported-by: Priya M.A <priyama2@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Reformat/tweak comment wording]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190918140103.24395-1-aneesh.kumar@linux.ibm.com
2019-09-21 08:36:53 +10:00
Linus Torvalds 45824fc0da powerpc updates for 5.4
- Initial support for running on a system with an Ultravisor, which is software
    that runs below the hypervisor and protects guests against some attacks by
    the hypervisor.
 
  - Support for building the kernel to run as a "Secure Virtual Machine", ie. as
    a guest capable of running on a system with an Ultravisor.
 
  - Some changes to our DMA code on bare metal, to allow devices with medium
    sized DMA masks (> 32 && < 59 bits) to use more than 2GB of DMA space.
 
  - Support for firmware assisted crash dumps on bare metal (powernv).
 
  - Two series fixing bugs in and refactoring our PCI EEH code.
 
  - A large series refactoring our exception entry code to use gas macros, both
    to make it more readable and also enable some future optimisations.
 
 As well as many cleanups and other minor features & fixups.
 
 Thanks to:
   Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh
   Kumar K.V, Anju T Sudhakar, Anshuman Khandual, Balbir Singh, Benjamin
   Herrenschmidt, Cédric Le Goater, Christophe JAILLET, Christophe Leroy,
   Christopher M. Riedl, Christoph Hellwig, Claudio Carvalho, Daniel Axtens,
   David Gibson, David Hildenbrand, Desnes A. Nunes do Rosario, Ganesh Goudar,
   Gautham R. Shenoy, Greg Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari
   Bathini, Joakim Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras,
   Lianbo Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar,
   Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan Chancellor,
   Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Qian Cai, Ram
   Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm, Sam Bobroff, Santosh Sivaraj,
   Segher Boessenkool, Sukadev Bhattiprolu, Thiago Bauermann, Thiago Jung
   Bauermann, Thomas Gleixner, Tom Lendacky, Vasant Hegde.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCAAxFiEEJFGtCPCthwEv2Y/bUevqPMjhpYAFAl2EtEcTHG1wZUBlbGxl
 cm1hbi5pZC5hdQAKCRBR6+o8yOGlgPfsD/9uXyBXn3anI/H08+mk74k5gCsmMQpn
 D442CD/ByogZcccp23yBTlhawtCE03hcHnCLygn0Xgd8a4YvHts/RGHUe3fPHqlG
 bEyZ7jsLVz5ebNZQP7r4eGs2pSzCajwJy2N9HJ/C1ojf15rrfRxoVJtnyhE2wXpm
 DL+6o2K+nUCB3gTQ1Inr3DnWzoGOOUfNTOea2u+J+yfHwGRqOBYpevwqiwy5eelK
 aRjUJCqMTvrzra49MeFwjo0Nt3/Y8UNcwA+JlGdeR8bRuWhFrYmyBRiZEKPaujNO
 5EAfghBBlB0KQCqvF/tRM/c0OftHqK59AMobP9T7u9oOaBXeF/FpZX/iXjzNDPsN
 j9Oo2tKLTu/YVEXqBFuREGP+znANr1Wo4CFyOG8SbvYz0HFjR6XbtRJsS+0e8GWl
 kqX5/ZhYz3lBnKSNe9jgWOrh/J0KCSFigBTEWJT3xsn4YE8x8kK2l9KPqAIldWEP
 sKb2UjGS7v0NKq+NvShH88Q9AeQUEIjTcg/9aDDQDe6FaRQ7KiF8bUxSdwSPi+Fn
 j0lnF6i+1ATWZKuCr85veVi7C5qoe/+MqalnmP7MxULyzgXLLxUgN0SzEYO6QofK
 LQK/VaH2XVr5+M5YAb7K4/NX5gbM3s1bKrCiUy4EyHNvgG7gricYdbz6HgAjKpR7
 oP0rHfgmVYvF1g==
 =WlW+
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "This is a bit late, partly due to me travelling, and partly due to a
  power outage knocking out some of my test systems *while* I was
  travelling.

   - Initial support for running on a system with an Ultravisor, which
     is software that runs below the hypervisor and protects guests
     against some attacks by the hypervisor.

   - Support for building the kernel to run as a "Secure Virtual
     Machine", ie. as a guest capable of running on a system with an
     Ultravisor.

   - Some changes to our DMA code on bare metal, to allow devices with
     medium sized DMA masks (> 32 && < 59 bits) to use more than 2GB of
     DMA space.

   - Support for firmware assisted crash dumps on bare metal (powernv).

   - Two series fixing bugs in and refactoring our PCI EEH code.

   - A large series refactoring our exception entry code to use gas
     macros, both to make it more readable and also enable some future
     optimisations.

  As well as many cleanups and other minor features & fixups.

  Thanks to: Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew
  Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman Khandual,
  Balbir Singh, Benjamin Herrenschmidt, Cédric Le Goater, Christophe
  JAILLET, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig,
  Claudio Carvalho, Daniel Axtens, David Gibson, David Hildenbrand,
  Desnes A. Nunes do Rosario, Ganesh Goudar, Gautham R. Shenoy, Greg
  Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari Bathini, Joakim
  Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras, Lianbo
  Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar,
  Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan
  Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver
  O'Halloran, Qian Cai, Ram Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm,
  Sam Bobroff, Santosh Sivaraj, Segher Boessenkool, Sukadev Bhattiprolu,
  Thiago Bauermann, Thiago Jung Bauermann, Thomas Gleixner, Tom
  Lendacky, Vasant Hegde"

* tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (264 commits)
  powerpc/mm/mce: Keep irqs disabled during lockless page table walk
  powerpc: Use ftrace_graph_ret_addr() when unwinding
  powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
  ftrace: Look up the address of return_to_handler() using helpers
  powerpc: dump kernel log before carrying out fadump or kdump
  docs: powerpc: Add missing documentation reference
  powerpc/xmon: Fix output of XIVE IPI
  powerpc/xmon: Improve output of XIVE interrupts
  powerpc/mm/radix: remove useless kernel messages
  powerpc/fadump: support holes in kernel boot memory area
  powerpc/fadump: remove RMA_START and RMA_END macros
  powerpc/fadump: update documentation about option to release opalcore
  powerpc/fadump: consider f/w load area
  powerpc/opalcore: provide an option to invalidate /sys/firmware/opal/core file
  powerpc/opalcore: export /sys/firmware/opal/core for analysing opal crashes
  powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP
  powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel
  powerpc/fadump: improve how crashed kernel's memory is reserved
  powerpc/fadump: consider reserved ranges while releasing memory
  powerpc/fadump: make crash memory ranges array allocation generic
  ...
2019-09-20 11:48:06 -07:00
Qian Cai ec5b705c48 powerpc/mm/radix: remove useless kernel messages
Booting a POWER9 PowerNV system generates a few messages below with
"____ptrval____" due to the pointers printed without a specifier
extension (i.e unadorned %p) are hashed to prevent leaking information
about the kernel memory layout.

radix-mmu: Initializing Radix MMU
radix-mmu: Partition table (____ptrval____)
radix-mmu: Mapped 0x0000000000000000-0x0000000040000000 with 1.00 GiB
pages (exec)
radix-mmu: Mapped 0x0000000040000000-0x0000002000000000 with 1.00 GiB
pages
radix-mmu: Mapped 0x0000200000000000-0x0000202000000000 with 1.00 GiB
pages
radix-mmu: Process table (____ptrval____) and radix root for kernel:
(____ptrval____)

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1566570120-16529-1-git-send-email-cai@lca.pw
2019-09-14 00:04:46 +10:00
Michael Ellerman dac39f7885 powerpc/64s: Remove overlaps_kvm_tmp()
kvm_tmp is now in .text and so doesn't need a special overlap check.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190911115746.12433-2-mpe@ellerman.id.au
2019-09-14 00:04:40 +10:00
Christoph Hellwig 7b86ac3371 pagewalk: separate function pointers from iterator data
The mm_walk structure currently mixed data and code.  Split out the
operations vectors into a new mm_walk_ops structure, and while we are
changing the API also declare the mm_walk structure inside the
walk_page_range and walk_page_vma functions.

Based on patch from Linus Torvalds.

Link: https://lore.kernel.org/r/20190828141955.22210-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-09-07 04:28:04 -03:00
Christoph Hellwig a520110e4a mm: split out a new pagewalk.h header from mm.h
Add a new header for the two handful of users of the walk_page_range /
walk_page_vma interface instead of polluting all users of mm.h with it.

Link: https://lore.kernel.org/r/20190828141955.22210-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-09-07 04:28:04 -03:00
Nicholas Piggin 2275d7b575 powerpc/64s/radix: introduce options to disable use of the tlbie instruction
Introduce two options to control the use of the tlbie instruction. A
boot time option which completely disables the kernel using the
instruction, this is currently incompatible with HASH MMU, KVM, and
coherent accelerators.

And a debugfs option can be switched at runtime and avoids using tlbie
for invalidating CPU TLBs for normal process and kernel address
mappings. Coherent accelerators are still managed with tlbie, as will
KVM partition scope translations.

Cross-CPU TLB flushing is implemented with IPIs and tlbiel. This is a
basic implementation which does not attempt to make any optimisation
beyond the tlbie implementation.

This is useful for performance testing among other things. For example
in certain situations on large systems, using IPIs may be faster than
tlbie as they can be directed rather than broadcast. Later we may also
take advantage of the IPIs to do more interesting things such as trim
the mm cpumask more aggressively.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190902152931.17840-7-npiggin@gmail.com
2019-09-05 14:22:41 +10:00
Nicholas Piggin 7d805accbe powerpc/64s: remove unnecessary translation cache flushes at boot
The various translation structure invalidations performed in early boot
when the MMU is off are not required, because everything is invalidated
immediately before a CPU first enables its MMU (see early_init_mmu
and early_init_mmu_secondary).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190902152931.17840-6-npiggin@gmail.com
2019-09-05 14:22:41 +10:00
Nicholas Piggin 7e71c428a6 powerpc/64s/pseries: radix flush translations before MMU is enabled at boot
Radix guests are responsible for managing their own translation caches,
so make them match bare metal radix and hash, and make each CPU flush
all its translations right before enabling its MMU.

Radix guests may not flush partition scope translations, so in
tlbiel_all, make these flushes conditional on CPU_FTR_HVMODE. Process
scope translations are the only type visible to the guest.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190902152931.17840-5-npiggin@gmail.com
2019-09-05 14:22:40 +10:00
Nicholas Piggin fd13daea5f powerpc/64s: make mmu_partition_table_set_entry TLB flush optional
No functional change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190902152931.17840-4-npiggin@gmail.com
2019-09-05 14:22:40 +10:00
Nicholas Piggin 99161de3a2 powerpc/64s/radix: tidy up TLB flushing code
There should be no functional changes.

- Use calls to existing radix_tlb.c functions in flush_partition.

- Rename radix__flush_tlb_lpid to radix__flush_all_lpid and similar,
  because they flush everything, matching flush_all_mm rather than
  flush_tlb_mm for the lpid.

- Remove some unused radix_tlb.c flush primitives.

Signed-off: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190902152931.17840-3-npiggin@gmail.com
2019-09-05 14:22:40 +10:00
Nicholas Piggin ed6546bdc6 powerpc/64s: remove register_process_table callback
This callback is only required because the partition table init comes
before process table allocation on powernv (aka bare metal aka native).

Change the order to allocate the process table first, and remove the
callback.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190902152931.17840-2-npiggin@gmail.com
2019-09-05 14:22:40 +10:00
Nicholas Piggin 9b123d1ea2 powerpc/64s/exception: reduce page fault unnecessary loads
This avoids 3 loads in the radix page fault case, 1 load in the
hash fault case, and 2 loads in the hash miss page fault case.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802105709.27696-37-npiggin@gmail.com
2019-08-30 11:14:59 +10:00
Michael Ellerman 9044adca78 Merge branch 'topic/ppc-kvm' into next
Merge our ppc-kvm topic branch to bring in the Ultravisor support
patches.
2019-08-30 09:52:57 +10:00
Claudio Carvalho 5223134029 powerpc/mm: Write to PTCR only if ultravisor disabled
In ultravisor enabled systems, PTCR becomes ultravisor privileged only
for writing and an attempt to write to it will cause a Hypervisor
Emulation Assitance interrupt.

This patch uses the set_ptcr_when_no_uv() function to restrict PTCR
writing to only when ultravisor is disabled.

Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190822034838.27876-6-cclaudio@linux.ibm.com
2019-08-30 09:40:16 +10:00
Michael Anderson 139a1d2842 powerpc/mm: Use UV_WRITE_PATE ucall to register a PATE
When Ultravisor (UV) is enabled, the partition table is stored in secure
memory and can only be accessed via the UV. The Hypervisor (HV) however
maintains a copy of the partition table in normal memory to allow Nest MMU
translations to occur (for normal VMs). The HV copy includes partition
table entries (PATE)s for secure VMs which would currently be unused
(Nest MMU translations cannot access secure memory) but they would be
needed as we add functionality.

This patch adds the UV_WRITE_PATE ucall which is used to update the PATE
for a VM (both normal and secure) when Ultravisor is enabled.

Signed-off-by: Michael Anderson <andmike@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[ cclaudio: Write the PATE in HV's table before doing that in UV's ]
Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Reviewed-by: Ryan Grimm <grimm@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190822034838.27876-5-cclaudio@linux.ibm.com
2019-08-30 09:40:15 +10:00
Christoph Hellwig f2902a2fb4 powerpc: use the generic dma coherent remap allocator
This switches to using common code for the DMA allocations, including
potential use of the CMA allocator if configured.

Switching to the generic code enables DMA allocations from atomic
context, which is required by the DMA API documentation, and also
adds various other minor features drivers start relying upon.  It
also makes sure we have on tested code base for all architectures
that require uncached pte bits for coherent DMA allocations.

Another advantage is that consistent memory allocations now share
the general vmalloc pool instead of needing an explicit careout
from it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> # tested on 8xx
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190814132230.31874-2-hch@lst.de
2019-08-28 23:19:34 +10:00
Christophe Leroy 12c3f1fd87 powerpc/32s: get rid of CPU_FTR_601 feature
Now that 601 is exclusive from other 6xx, CPU_FTR_601 and
associated fixups are useless.

Drop this feature and use #ifdefs instead.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ecdb7194a17dbfa01865df6a82979533adc2c70b.1566834712.git.christophe.leroy@c-s.fr
2019-08-28 23:19:33 +10:00
Christophe Leroy 163918fc57 powerpc/mm: split out early ioremap path.
ioremap does things differently depending on whether
SLAB is available or not at different levels.

Try to separate the early path from the beginning.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3acd2dbe04b04f111475e7a59f2b6f2ab9b95ab6.1566309263.git.christophe.leroy@c-s.fr
2019-08-27 13:03:35 +10:00
Christophe Leroy 4a45b7460c powerpc/mm: refactor ioremap vm area setup.
PPC32 and PPC64 are doing the same once SLAB is available.
Create a do_ioremap() function that calls get_vm_area and
do the mapping.

For PPC64, we add the 4K PFN hack sanity check to __ioremap_caller()
in order to avoid using __ioremap_at(). Other checks in __ioremap_at()
are irrelevant for __ioremap_caller().

On PPC64, VM area is allocated in the range [ioremap_bot ; IOREMAP_END]
On PPC32, VM area is allocated in the range [VMALLOC_START ; VMALLOC_END]

Lets define IOREMAP_START is ioremap_bot for PPC64, and alias
IOREMAP_START/END to VMALLOC_START/END on PPC32

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/42e7e36ad32e0fdf76692426cc642799c9f689b8.1566309263.git.christophe.leroy@c-s.fr
2019-08-27 13:03:35 +10:00
Christophe Leroy 191e42063a powerpc/mm: refactor ioremap_range() and use ioremap_page_range()
book3s64's ioremap_range() is almost same as fallback ioremap_range(),
except that it calls radix__ioremap_range() when radix is enabled.

radix__ioremap_range() is also very similar to the other ones, expect
that it calls ioremap_page_range when slab is available.

PPC32 __ioremap_caller() have a loop doing the same thing as
ioremap_range() so use it on PPC32 as well.

Lets keep only one version of ioremap_range() which calls
ioremap_page_range() on all platforms when slab is available.

At the same time, drop the nid parameter which is not used.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4b1dca7096b01823b101be7338983578641547f1.1566309263.git.christophe.leroy@c-s.fr
2019-08-27 13:03:35 +10:00
Christophe Leroy f381d5711f powerpc/mm: Move ioremap functions out of pgtable_32/64.c
Create ioremap_32.c and ioremap_64.c and move respective ioremap
functions out of pgtable_32.c and pgtable_64.c

In the meantime, fix a few comments and changes a printk() to
pr_warn(). Also fix a few oversplitted lines.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b5c8b02ccefd4ede64c61b53cf64fb5dacb35740.1566309263.git.christophe.leroy@c-s.fr
2019-08-27 13:03:35 +10:00
Christophe Leroy 7cd9b317b6 powerpc/mm: make ioremap_bot common to all
Drop multiple definitions of ioremap_bot and make one common to
all subarches.

Only CONFIG_PPC_BOOK3E_64 had a global static init value for
ioremap_bot. Now ioremap_bot is set in early_init_mmu_global().

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/920eebfd9f36f14c79d1755847f5bf7c83703bdd.1566309262.git.christophe.leroy@c-s.fr
2019-08-27 13:03:34 +10:00
Christophe Leroy edfe1a5679 powerpc/mm: move ioremap_prot() into ioremap.c
Both ioremap_prot() are idenfical, move them into ioremap.c

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0b3eb0e0f1490a99fd6c983e166fb8946233f151.1566309262.git.christophe.leroy@c-s.fr
2019-08-27 13:03:34 +10:00
Christophe Leroy 4634c375db powerpc/mm: move common 32/64 bits ioremap functions into ioremap.c
ioremap(), ioremap_wc() and ioremap_coherent() are now identical on
PPC32 and PPC64 as iowa_is_active() will always return false on
PPC32. Move them into a new common location called ioremap.c

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6223803ce024d6ab4dfaa919f44098aed5b4bc33.1566309262.git.christophe.leroy@c-s.fr
2019-08-27 13:03:34 +10:00
Christophe Leroy 14b4d97669 powerpc/mm: rework io-workaround invocation.
ppc_md.ioremap() is only used for I/O workaround on CELL platform,
so indirect function call can be avoided.

This patch reworks the io-workaround and ioremap() functions to
use the global 'io_workaround_inited' flag for the activation
of io-workaround.

When CONFIG_PPC_IO_WORKAROUNDS or CONFIG_PPC_INDIRECT_MMIO are not
selected, the I/O workaround ioremap() voids and the global flag is
not used.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5fa3ef069fbd0f152512afaae19e7a60161454cf.1566309262.git.christophe.leroy@c-s.fr
2019-08-27 13:03:34 +10:00
Christophe Leroy 492643e81e powerpc/mm: drop function __ioremap()
__ioremap() is not used anymore, drop it.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ccc439f481a0884e00a6be1bab44bab2a4477fea.1566309262.git.christophe.leroy@c-s.fr
2019-08-27 13:03:33 +10:00
Christophe Leroy 8aee077292 powerpc/mm: drop ppc_md.iounmap() and __iounmap()
ppc_md.iounmap() is never set, drop it.

Once ppc_md.iounmap() is gone, iounmap() remains the only user of
__iounmap() and iounmap() does nothing else than calling __iounmap().
So drop iounmap() and make __iounmap() the new iounmap().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d73ba92bb7a387cc58cc34666d7f5158a45851b0.1566309262.git.christophe.leroy@c-s.fr
2019-08-27 13:03:33 +10:00
Nicholas Piggin 31f210cf42 powerpc/64s/radix: Fix memory hot-unplug page table split
create_physical_mapping expects physical addresses, but splitting
these mapping on hot unplug is supplying virtual (effective)
addresses.

Fixes: 4dd5f8a99e ("powerpc/mm/radix: Split linear mapping on hot-unplug")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190724084638.24982-2-npiggin@gmail.com
2019-08-20 21:22:19 +10:00
Nicholas Piggin 8f51e39294 powerpc/64s/radix: Fix memory hotplug section page table creation
create_physical_mapping expects physical addresses, but creating and
splitting these mappings after boot is supplying virtual (effective)
addresses. This can be irritated by booting with mem= to limit memory
then probing an unused physical memory range:

  echo <addr> > /sys/devices/system/memory/probe

This mostly works by accident, firstly because __va(__va(x)) == __va(x)
so the virtual address does not get corrupted. Secondly because pfn_pte
masks out the upper bits of the pfn beyond the physical address limit,
so a pfn constructed with a 0xc000000000000000 virtual linear address
will be masked back to the correct physical address in the pte.

Fixes: 6cc27341b2 ("powerpc/mm: add radix__create_section_mapping()")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190724084638.24982-1-npiggin@gmail.com
2019-08-20 21:22:18 +10:00
Christophe Leroy f204338f8e powerpc/mm: ppc 603 doesn't need update_mmu_cache()
On powerpc 603, there is no hash table so get out of
update_mmu_cache() early.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6133e0f115d955fac4061536dab0fa7480a1c433.1565933217.git.christophe.leroy@c-s.fr
2019-08-20 21:22:14 +10:00
Christophe Leroy f49f4e2b68 powerpc/mm: Simplify update_mmu_cache() on BOOK3S32
On BOOK3S32, hash_preload() neither use is_exec nor trap,
so drop those parameters and simplify update_mmu_cached().

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/35f143c6fe29f9fd25c7f3cd4448ae401029ce3c.1565933217.git.christophe.leroy@c-s.fr
2019-08-20 21:22:14 +10:00
Christophe Leroy e5a1edb9fe powerpc/mm: move update_mmu_cache() into book3s hash utils.
update_mmu_cache() is only for BOOK3S, and can be simplified for
BOOK3S32.

Move it out of mem.c into respective BOOK3S32 and BOOK3S64 files
containing hash utils.

BOOK3S64 version of hash_preload() is only used locally, declare it
static.

Remove the radix_enabled() stuff in BOOK3S32 version.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/107aaf43583a5f5d09e0d4e84c4c4390ecfcd512.1565933217.git.christophe.leroy@c-s.fr
2019-08-20 21:22:14 +10:00
Christophe Leroy 4c1616ef03 powerpc/mm: move FSL_BOOK3 version of update_mmu_cache()
Move FSL_BOOK3E version of update_mmu_cache() at the same
place as book3e_hugetlb_preload() as update_mmu_cache() is
the only user of book3e_hugetlb_preload().

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4d69fdc86df9c74adc71a60331a86f6afb8b5e9e.1565933217.git.christophe.leroy@c-s.fr
2019-08-20 21:22:14 +10:00
Christophe Leroy d964211791 powerpc/mm: define empty update_mmu_cache() as static inline
Only BOOK3S and FSL_BOOK3E have a usefull update_mmu_cache().

For the others, just define it static inline.

In the meantime, simplify the FSL_BOOK3E related ifdef as
book3e_hugetlb_preload() only exists when CONFIG_PPC_FSL_BOOK3E
is selected.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/668aba4db6b9af6d8a151174e11a4289f1a6bbcd.1565933217.git.christophe.leroy@c-s.fr
2019-08-20 21:22:14 +10:00
Christophe Leroy ad628a34ec powerpc/mm: don't display empty early ioremap area
On the 8xx, the layout displayed at boot is:

[    0.000000] Memory: 121856K/131072K available (5728K kernel code, 592K rwdata, 1248K rodata, 560K init, 448K bss, 9216K reserved, 0K cma-reserved)
[    0.000000] Kernel virtual memory layout:
[    0.000000]   * 0xffefc000..0xffffc000  : fixmap
[    0.000000]   * 0xffefc000..0xffefc000  : early ioremap
[    0.000000]   * 0xc9000000..0xffefc000  : vmalloc & ioremap
[    0.000000] SLUB: HWalign=16, Order=0-3, MinObjects=0, CPUs=1, Nodes=1

Remove display of an empty early ioremap.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f6267226038cb25a839b567319e240576e3f8565.1565793287.git.christophe.leroy@c-s.fr
2019-08-20 21:22:13 +10:00
Christophe Leroy 9d6d712fbf powerpc/32s: Fix boot failure with DEBUG_PAGEALLOC without KASAN.
When KASAN is selected, the definitive hash table has to be
set up later, but there is already an early temporary one.

When KASAN is not selected, there is no early hash table,
so the setup of the definitive hash table cannot be delayed.

Fixes: 72f208c6a8 ("powerpc/32s: move hash code patching out of MMU_init_hw()")
Cc: stable@vger.kernel.org # v5.2+
Reported-by: Jonathan Neuschafer <j.neuschaefer@gmx.net>
Tested-by: Jonathan Neuschafer <j.neuschaefer@gmx.net>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b7860c5e1e784d6b96ba67edf47dd6cbc2e78ab6.1565776892.git.christophe.leroy@c-s.fr
2019-08-20 21:22:13 +10:00
Christophe Leroy 663c0c9496 powerpc/kasan: Fix shadow area set up for modules.
When loading modules, from time to time an Oops is encountered during
the init of shadow area for globals. This is due to the last page not
always being mapped depending on the exact distance between the start
and the end of the shadow area and the alignment with the page
addresses.

Fix this by aligning the starting address with the page address.

Fixes: 2edb16efc8 ("powerpc/32: Add KASAN support")
Cc: stable@vger.kernel.org # v5.2+
Reported-by: Erhard F. <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4f887e9b77d0d725cbb52035c7ece485c1c5fc14.1565361881.git.christophe.leroy@c-s.fr
2019-08-20 21:22:11 +10:00
Christophe Leroy 45ff3c5595 powerpc/kasan: Fix parallel loading of modules.
Parallel loading of modules may lead to bad setup of shadow page table
entries.

First, lets align modules so that two modules never share the same
shadow page.

Second, ensure that two modules cannot allocate two page tables for
the same PMD entry at the same time. This is done by using
init_mm.page_table_lock in the same way as __pte_alloc_kernel()

Fixes: 2edb16efc8 ("powerpc/32: Add KASAN support")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c97284f912128cbc3f2fe09d68e90e65fb3e6026.1565361876.git.christophe.leroy@c-s.fr
2019-08-20 21:22:11 +10:00
Christophe Leroy 65e701b2d2 powerpc/ptdump: drop non vital #ifdefs
hashpagetable.c is only compiled when CONFIG_PPC_BOOK3S_64 is
defined, so drop the test and its 'else' branch.

Use IS_ENABLED(CONFIG_PPC_PSERIES) instead of #ifdef, this allows the
code to be checked at any build. It is still optimised out by GCC.

Use IS_ENABLED(CONFIG_PPC_64K_PAGES) instead of #ifdef.

Use IS_ENABLED(CONFIG_SPARSEMEN_VMEMMAP) instead of #ifdef.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c8998ed32e4e3954b56a8dacecfe43319a2a0483.1565786091.git.christophe.leroy@c-s.fr
2019-08-20 21:22:09 +10:00
Christophe Leroy f3a2ac0589 powerpc/ptdump: get out of note_prot_wx() when CONFIG_PPC_DEBUG_WX is not selected.
When CONFIG_PPC_DEBUG_WX, note_prot_wx() is useless.

Get out of it early and inconditionnally in that case,
so that GCC can kick all the code out.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ff6c8f631bd4ce3a10e0cc241eb569816187bc20.1565786091.git.christophe.leroy@c-s.fr
2019-08-20 21:22:09 +10:00
Christophe Leroy 8224235272 powerpc/ptdump: drop dummy KERN_VIRT_START on PPC32
PPC32 doesn't have KERN_VIRT_START. Make PAGE_OFFSET the
default starting address for the dump, and drop the dummy
definition of KERN_VIRT_START. Only use KERN_VIRT_START for
non radix PPC64.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/334632b1df4775b0ccf3bdc8d6b201d14e3daedd.1565786091.git.christophe.leroy@c-s.fr
2019-08-20 21:22:09 +10:00
Christophe Leroy e033829d2a powerpc/ptdump: fix walk_pagetables() address mismatch
walk_pagetables() always walk the entire pgdir from address 0
but considers PAGE_OFFSET or KERN_VIRT_START as the starting
address of the walk, resulting in a possible mismatch in the
displayed addresses.

Ex: on PPC32, when KERN_VIRT_START was locally defined as
PAGE_OFFSET, ptdump displayed 0x80000000
instead of 0xc0000000 for the first kernel page,
because 0xc0000000 + 0xc0000000 = 0x80000000

Start the walk at st->start_address instead of starting at 0.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5aa2ac513295f594cce8ddb1c649f61947bd063d.1565786091.git.christophe.leroy@c-s.fr
2019-08-20 21:22:08 +10:00
Christophe Leroy 7c7a532ba3 powerpc/ptdump: Fix addresses display on PPC32
Commit 453d87f6a8 ("powerpc/mm: Warn if W+X pages found on boot")
wrongly changed KERN_VIRT_START from 0 to PAGE_OFFSET, leading to a
shift in the displayed addresses.

Lets revert that change to resync walk_pagetables()'s addr val and
pgd_t pointer for PPC32.

Fixes: 453d87f6a8 ("powerpc/mm: Warn if W+X pages found on boot")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/eb4d626514e22f85814830012642329018ef6af9.1565786091.git.christophe.leroy@c-s.fr
2019-08-20 21:22:08 +10:00
Gautham R. Shenoy c784be435d powerpc/pseries: Fix cpu_hotplug_lock acquisition in resize_hpt()
The calls to arch_add_memory()/arch_remove_memory() are always made
with the read-side cpu_hotplug_lock acquired via memory_hotplug_begin().
On pSeries, arch_add_memory()/arch_remove_memory() eventually call
resize_hpt() which in turn calls stop_machine() which acquires the
read-side cpu_hotplug_lock again, thereby resulting in the recursive
acquisition of this lock.

In the absence of CONFIG_PROVE_LOCKING, we hadn't observed a system
lockup during a memory hotplug operation because cpus_read_lock() is a
per-cpu rwsem read, which, in the fast-path (in the absence of the
writer, which in our case is a CPU-hotplug operation) simply
increments the read_count on the semaphore. Thus a recursive read in
the fast-path doesn't cause any problems.

However, we can hit this problem in practice if there is a concurrent
CPU-Hotplug operation in progress which is waiting to acquire the
write-side of the lock. This will cause the second recursive read to
block until the writer finishes. While the writer is blocked since the
first read holds the lock. Thus both the reader as well as the writers
fail to make any progress thereby blocking both CPU-Hotplug as well as
Memory Hotplug operations.

Memory-Hotplug				CPU-Hotplug
CPU 0					CPU 1
------                                  ------

1. down_read(cpu_hotplug_lock.rw_sem)
   [memory_hotplug_begin]
					2. down_write(cpu_hotplug_lock.rw_sem)
					[cpu_up/cpu_down]
3. down_read(cpu_hotplug_lock.rw_sem)
   [stop_machine()]

Lockdep complains as follows in these code-paths.

 swapper/0/1 is trying to acquire lock:
 (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: stop_machine+0x2c/0x60

but task is already holding lock:
(____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: mem_hotplug_begin+0x20/0x50

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(cpu_hotplug_lock.rw_sem);
   lock(cpu_hotplug_lock.rw_sem);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 3 locks held by swapper/0/1:
  #0: (____ptrval____) (&dev->mutex){....}, at: __driver_attach+0x12c/0x1b0
  #1: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: mem_hotplug_begin+0x20/0x50
  #2: (____ptrval____) (mem_hotplug_lock.rw_sem){++++}, at: percpu_down_write+0x54/0x1a0

stack backtrace:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc5-58373-gbc99402235f3-dirty #166
 Call Trace:
   dump_stack+0xe8/0x164 (unreliable)
   __lock_acquire+0x1110/0x1c70
   lock_acquire+0x240/0x290
   cpus_read_lock+0x64/0xf0
   stop_machine+0x2c/0x60
   pseries_lpar_resize_hpt+0x19c/0x2c0
   resize_hpt_for_hotplug+0x70/0xd0
   arch_add_memory+0x58/0xfc
   devm_memremap_pages+0x5e8/0x8f0
   pmem_attach_disk+0x764/0x830
   nvdimm_bus_probe+0x118/0x240
   really_probe+0x230/0x4b0
   driver_probe_device+0x16c/0x1e0
   __driver_attach+0x148/0x1b0
   bus_for_each_dev+0x90/0x130
   driver_attach+0x34/0x50
   bus_add_driver+0x1a8/0x360
   driver_register+0x108/0x170
   __nd_driver_register+0xd0/0xf0
   nd_pmem_driver_init+0x34/0x48
   do_one_initcall+0x1e0/0x45c
   kernel_init_freeable+0x540/0x64c
   kernel_init+0x2c/0x160
   ret_from_kernel_thread+0x5c/0x68

Fix this issue by
  1) Requiring all the calls to pseries_lpar_resize_hpt() be made
     with cpu_hotplug_lock held.

  2) In pseries_lpar_resize_hpt() invoke stop_machine_cpuslocked()
     as a consequence of 1)

  3) To satisfy 1), in hpt_order_set(), call mmu_hash_ops.resize_hpt()
     with cpu_hotplug_lock held.

Fixes: dbcf929c00 ("powerpc/pseries: Add support for hash table resizing")
Cc: stable@vger.kernel.org # v4.11+
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1557906352-29048-1-git-send-email-ego@linux.vnet.ibm.com
2019-08-19 13:20:23 +10:00
Michael Ellerman 4215fa2d7d Merge branch 'fixes' into next
Merge in our fixes branch, which brings in clone3() as well as some
implicit fallthrough fixes we want in next.
2019-08-19 12:43:13 +10:00