linux-stable.git/arch/xtensa/include, branch linux-4.3.y

xtensa: fix secondary core boot in SMP

2016-02-19T22:28:28+00:00

commit ab45fb145096799dabd18afc58bb5f97171017cd upstream.

There are multiple factors adding to the issue in different
configurations:

- commit 17290231df16eeee ("xtensa: add fixup for double exception raised
  in window overflow") added function window_overflow_restore_a0_fixup to
  double exception vector overlapping reset vector location of secondary
  processor cores.
- on MMUv2 cores RESET_VECTOR1_VADDR may point to uncached kernel memory
  making code overlapping depend on cache type and size, so that without
  cache or with WT cache reset vector code overwrites double exception
  code, making issue even harder to detect.
- on MMUv3 cores RESET_VECTOR1_VADDR may point to unmapped area, as
  MMUv3 cores change virtual address map to match MMUv2 layout, but
  reset vector virtual address is given for the original MMUv3 mapping.
- physical memory region of the secondary reset vector is not reserved
  in the physical memory map, and thus may be allocated and overwritten
  at arbitrary moment.

Fix it as follows:

- move window_overflow_restore_a0_fixup code to .text section.
- define RESET_VECTOR1_VADDR so that it points to reset vector in the
  cacheable MMUv2 map for cores with MMU.
- reserve reset vector region in the physical memory map. Drop separate
  literal section and build mxhead.S with text section literals.

Signed-off-by: Max Filippov 
Signed-off-by: Greg Kroah-Hartman

xtensa: fixes for configs without loop option

2016-02-19T22:28:28+00:00

commit 5029615e25dc5040beb065f36743c127a8e51497 upstream.

Build-time fixes:
- make lbeg/lend/lcount save/restore conditional on kernel entry;
- don't clear lcount in platform_restart functions unconditionally.

Run-time fixes:
- use correct end of range register in __endla paired with __loopt, not
  the unused temporary register. This fixes .bss zero-initialization.
  Update comments in asmmacro.h;
- don't clobber a10 in the usercopy that leads to access to unmapped
  memory.

Signed-off-by: Max Filippov 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile

2015-10-04T15:31:13+00:00

Pull strscpy string copy function implementation from Chris Metcalf.

Chris sent this during the merge window, but I waffled back and forth on
the pull request, which is why it's going in only now.

The new "strscpy()" function is definitely easier to use and more secure
than either strncpy() or strlcpy(), both of which are horrible nasty
interfaces that have serious and irredeemable problems.

strncpy() has a useless return value, and doesn't NUL-terminate an
overlong result.  To make matters worse, it pads a short result with
zeroes, which is a performance disaster if you have big buffers.

strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking
the insane NUL padding, but having a differently broken return value
which returns the original length of the source string.  Which means
that it will read characters past the count from the source buffer, and
you have to trust the source to be properly terminated.  It also makes
error handling fragile, since the test for overflow is unnecessarily
subtle.

strscpy() avoids both these problems, guaranteeing the NUL termination
(but not excessive padding) if the destination size wasn't zero, and
making the overflow condition very obvious by returning -E2BIG.  It also
doesn't read past the size of the source, and can thus be used for
untrusted source data too.

So why did I waffle about this for so long?

Every time we introduce a new-and-improved interface, people start doing
these interminable series of trivial conversion patches.

And every time that happens, somebody does some silly mistake, and the
conversion patch to the improved interface actually makes things worse.
Because the patch is mindnumbing and trivial, nobody has the attention
span to look at it carefully, and it's usually done over large swatches
of source code which means that not every conversion gets tested.

So I'm pulling the strscpy() support because it *is* a better interface.
But I will refuse to pull mindless conversion patches.  Use this in
places where it makes sense, but don't do trivial patches to fix things
that aren't actually known to be broken.

* 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  tile: use global strscpy() rather than private copy
  string: provide strscpy()
  Make asm/word-at-a-time.h available on all architectures

dma-mapping: consolidate dma_set_mask

2015-09-10T20:29:01+00:00

Almost everyone implements dma_set_mask the same way, although some time
that's hidden in ->set_dma_mask methods.

This patch consolidates those into a common implementation that either
calls ->set_dma_mask if present or otherwise uses the default
implementation.  Some architectures used to only call ->set_dma_mask
after the initial checks, and those instance have been fixed to do the
full work.  h8300 implemented dma_set_mask bogusly as a no-ops and has
been fixed.

Unfortunately some architectures overload unrelated semantics like changing
the dma_ops into it so we still need to allow for an architecture override
for now.

[jcmvbkbc@gmail.com: fix xtensa]
Signed-off-by: Christoph Hellwig 
Cc: Arnd Bergmann 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Cc: Michal Simek 
Cc: Jonas Bonn 
Cc: Chris Metcalf 
Cc: Guan Xuetao 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Andy Shevchenko 
Signed-off-by: Max Filippov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dma-mapping: consolidate dma_supported

2015-09-10T20:29:01+00:00

Most architectures just call into ->dma_supported, but some also return 1
if the method is not present, or 0 if no dma ops are present (although
that should never happeb). Consolidate this more broad version into
common code.

Also fix h8300 which inorrectly always returned 0, which would have been
a problem if it's dma_set_mask implementation wasn't a similarly buggy
noop.

As a few architectures have much more elaborate implementations, we
still allow for arch overrides.

[jcmvbkbc@gmail.com: fix xtensa]
Signed-off-by: Christoph Hellwig 
Cc: Arnd Bergmann 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Cc: Michal Simek 
Cc: Jonas Bonn 
Cc: Chris Metcalf 
Cc: Guan Xuetao 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Andy Shevchenko 
Signed-off-by: Max Filippov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dma-mapping: cosolidate dma_mapping_error

2015-09-10T20:29:01+00:00

Currently there are three valid implementations of dma_mapping_error:

 (1) call ->mapping_error
 (2) check for a hardcoded error code
 (3) always return 0

This patch provides a common implementation that calls ->mapping_error
if present, then checks for DMA_ERROR_CODE if defined or otherwise
returns 0.

[jcmvbkbc@gmail.com: fix xtensa]
Signed-off-by: Christoph Hellwig 
Cc: Arnd Bergmann 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Cc: Michal Simek 
Cc: Jonas Bonn 
Cc: Chris Metcalf 
Cc: Guan Xuetao 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Andy Shevchenko 
Signed-off-by: Max Filippov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dma-mapping: consolidate dma_{alloc,free}_noncoherent

2015-09-10T20:29:01+00:00

Most architectures do not support non-coherent allocations and either
define dma_{alloc,free}_noncoherent to their coherent versions or stub
them out.

Openrisc uses dma_{alloc,free}_attrs to implement them, and only Mips
implements them directly.

This patch moves the Openrisc version to common code, and handles the
DMA_ATTR_NON_CONSISTENT case in the mips dma_map_ops instance.

Note that actual non-coherent allocations require a dma_cache_sync
implementation, so if non-coherent allocations didn't work on
an architecture before this patch they still won't work after it.

[jcmvbkbc@gmail.com: fix xtensa]
Signed-off-by: Christoph Hellwig 
Cc: Arnd Bergmann 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Cc: Michal Simek 
Cc: Jonas Bonn 
Cc: Chris Metcalf 
Cc: Guan Xuetao 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Andy Shevchenko 
Signed-off-by: Max Filippov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}

2015-09-10T20:29:01+00:00

Since 2009 we have a nice asm-generic header implementing lots of DMA API
functions for architectures using struct dma_map_ops, but unfortunately
it's still missing a lot of APIs that all architectures still have to
duplicate.

This series consolidates the remaining functions, although we still need
arch opt outs for two of them as a few architectures have very
non-standard implementations.

This patch (of 5):

The coherent DMA allocator works the same over all architectures supporting
dma_map operations.

This patch consolidates them and converges the minor differences:

 - the debug_dma helpers are now called from all architectures, including
   those that were previously missing them
 - dma_alloc_from_coherent and dma_release_from_coherent are now always
   called from the generic alloc/free routines instead of the ops
   dma-mapping-common.h always includes dma-coherent.h to get the defintions
   for them, or the stubs if the architecture doesn't support this feature
 - checks for ->alloc / ->free presence are removed.  There is only one
   magic instead of dma_map_ops without them (mic_dma_ops) and that one
   is x86 only anyway.

Besides that only x86 needs special treatment to replace a default devices
if none is passed and tweak the gfp_flags.  An optional arch hook is provided
for that.

[linux@roeck-us.net: fix build]
[jcmvbkbc@gmail.com: fix xtensa]
Signed-off-by: Christoph Hellwig 
Cc: Arnd Bergmann 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Cc: Michal Simek 
Cc: Jonas Bonn 
Cc: Chris Metcalf 
Cc: Guan Xuetao 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Andy Shevchenko 
Signed-off-by: Guenter Roeck 
Signed-off-by: Max Filippov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2015-09-08T21:35:59+00:00

Pull libnvdimm updates from Dan Williams:
 "This update has successfully completed a 0day-kbuild run and has
  appeared in a linux-next release.  The changes outside of the typical
  drivers/nvdimm/ and drivers/acpi/nfit.[ch] paths are related to the
  removal of IORESOURCE_CACHEABLE, the introduction of memremap(), and
  the introduction of ZONE_DEVICE + devm_memremap_pages().

  Summary:

   - Introduce ZONE_DEVICE and devm_memremap_pages() as a generic
     mechanism for adding device-driver-discovered memory regions to the
     kernel's direct map.

     This facility is used by the pmem driver to enable pfn_to_page()
     operations on the page frames returned by DAX ('direct_access' in
     'struct block_device_operations').

     For now, the 'memmap' allocation for these "device" pages comes
     from "System RAM".  Support for allocating the memmap from device
     memory will arrive in a later kernel.

   - Introduce memremap() to replace usages of ioremap_cache() and
     ioremap_wt().  memremap() drops the __iomem annotation for these
     mappings to memory that do not have i/o side effects.  The
     replacement of ioremap_cache() with memremap() is limited to the
     pmem driver to ease merging the api change in v4.3.

     Completion of the conversion is targeted for v4.4.

   - Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem
     driver, update the VFS DAX implementation and PMEM api to provide
     persistence guarantees for kernel operations on a DAX mapping.

   - Convert the ACPI NFIT 'BLK' driver to map the block apertures as
     cacheable to improve performance.

   - Miscellaneous updates and fixes to libnvdimm including support for
     issuing "address range scrub" commands, clarifying the optimal
     'sector size' of pmem devices, a clarification of the usage of the
     ACPI '_STA' (status) property for DIMM devices, and other minor
     fixes"

* tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (34 commits)
  libnvdimm, pmem: direct map legacy pmem by default
  libnvdimm, pmem: 'struct page' for pmem
  libnvdimm, pfn: 'struct page' provider infrastructure
  x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB
  add devm_memremap_pages
  mm: ZONE_DEVICE for "device memory"
  mm: move __phys_to_pfn and __pfn_to_phys to asm/generic/memory_model.h
  dax: drop size parameter to ->direct_access()
  nd_blk: change aperture mapping from WC to WB
  nvdimm: change to use generic kvfree()
  pmem, dax: have direct_access use __pmem annotation
  dax: update I/O path to do proper PMEM flushing
  pmem: add copy_from_iter_pmem() and clear_pmem()
  pmem, x86: clean up conditional pmem includes
  pmem: remove layer when calling arch_has_wmb_pmem()
  pmem, x86: move x86 PMEM API to new pmem.h header
  libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option
  pmem: switch to devm_ allocations
  devres: add devm_memremap
  libnvdimm, btt: write and validate parent_uuid
  ...

Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-09-03T22:46:07+00:00

Pull locking and atomic updates from Ingo Molnar:
 "Main changes in this cycle are:

   - Extend atomic primitives with coherent logic op primitives
     (atomic_{or,and,xor}()) and deprecate the old partial APIs
     (atomic_{set,clear}_mask())

     The old ops were incoherent with incompatible signatures across
     architectures and with incomplete support.  Now every architecture
     supports the primitives consistently (by Peter Zijlstra)

   - Generic support for 'relaxed atomics':

       - _acquire/release/relaxed() flavours of xchg(), cmpxchg() and {add,sub}_return()
       - atomic_read_acquire()
       - atomic_set_release()

     This came out of porting qwrlock code to arm64 (by Will Deacon)

   - Clean up the fragile static_key APIs that were causing repeat bugs,
     by introducing a new one:

       DEFINE_STATIC_KEY_TRUE(name);
       DEFINE_STATIC_KEY_FALSE(name);

     which define a key of different types with an initial true/false
     value.

     Then allow:

       static_branch_likely()
       static_branch_unlikely()

     to take a key of either type and emit the right instruction for the
     case.  To be able to know the 'type' of the static key we encode it
     in the jump entry (by Peter Zijlstra)

   - Static key self-tests (by Jason Baron)

   - qrwlock optimizations (by Waiman Long)

   - small futex enhancements (by Davidlohr Bueso)

   - ... and misc other changes"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
  jump_label/x86: Work around asm build bug on older/backported GCCs
  locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operations
  locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.h
  locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics
  locking/qrwlock: Implement queue_write_unlock() using smp_store_release()
  locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition
  locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t'
  locking, asm-generic: Rework atomic-long.h to avoid bulk code duplication
  locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations
  locking, compiler.h: Cast away attributes in the WRITE_ONCE() magic
  locking/static_keys: Make verify_keys() static
  jump label, locking/static_keys: Update docs
  locking/static_keys: Provide a selftest
  jump_label: Provide a self-test
  s390/uaccess, locking/static_keys: employ static_branch_likely()
  x86, tsc, locking/static_keys: Employ static_branch_likely()
  locking/static_keys: Add selftest
  locking/static_keys: Add a new static_key interface
  locking/static_keys: Rework update logic
  locking/static_keys: Add static_key_{en,dis}able() helpers
  ...