linux.git/include/asm-generic, branch v3.15-rc4

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2014-05-04T21:34:50+00:00

Pull arm64 fixes from Catalin Marinas:
 "These are mostly arm64 fixes with an additional arm(64) platform fix
  for the initialisation of vexpress clocks (the latter only affecting
  arm64; the arch/arm64 code is SoC agnostic and does not rely on early
  SoC-specific calls)

   - vexpress platform clocks initialisation moved earlier following the
     arm64 move of of_clk_init() call in a previous commit
   - Default DMA ops changed to non-coherent to preserve compatibility
     with 32-bit ARM DT files.  The "dma-coherent" property can be used
     to explicitly mark a device coherent.  The Applied Micro DT file
     has been updated to avoid DMA cache maintenance for the X-Gene SATA
     controller (the only arm64 related driver with such assumption in
     -rc mainline)
   - Fixmap correction for earlyprintk
   - kern_addr_valid() fix for huge pages"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  vexpress: Initialise the sysregs before setting up the clocks
  arm64: Mark the Applied Micro X-Gene SATA controller as DMA coherent
  arm64: Use bus notifiers to set per-device coherent DMA ops
  arm64: Make default dma_ops to be noncoherent
  arm64: fixmap: fix missing sub-page offset for earlyprintk
  arm64: Fix for the arm64 kern_addr_valid() function

arm64: fixmap: fix missing sub-page offset for earlyprintk

2014-05-03T21:20:31+00:00

Commit d57c33c5daa4 (add generic fixmap.h) added (among other
similar things) set_fixmap_io to deal with early ioremap of devices.

More recently, commit bf4b558eba92 (arm64: add early_ioremap support)
converted the arm64 earlyprintk to use set_fixmap_io. A side effect of
this conversion is that my virtual machines have stopped booting when
I pass "earlyprintk=uart8250-8bit,0x3f8" to the guest kernel.

Turns out that the new earlyprintk code doesn't care at all about
sub-page offsets, and just assumes that the earlyprintk device will
be page-aligned. Obviously, that doesn't play well with the above example.

Further investigation shows that set_fixmap_io uses __set_fixmap instead
of __set_fixmap_offset. A fix is to introduce a set_fixmap_offset_io that
uses the latter, and to remove the superflous call to fix_to_virt
(which only returns the value that set_fixmap_io has already given us).

With this applied, my VMs are back in business. Tested on a Cortex-A57
platform with kvmtool as platform emulation.

Cc: Will Deacon 
Acked-by: Mark Salter 
Acked-by: Arnd Bergmann 
Signed-off-by: Marc Zyngier 
Signed-off-by: Catalin Marinas

word-at-a-time: simplify big-endian zero_bytemask macro

2014-05-01T15:57:44+00:00

This is simpler and cleaner.  Depending on architecture, a smart
compiler may or may not generate the same code.

Acked-by: Will Deacon 
Signed-off-by: Linus Torvalds

word-at-a-time: avoid undefined behaviour in zero_bytemask macro

2014-04-27T22:20:05+00:00

The asm-generic, big-endian version of zero_bytemask creates a mask of
bytes preceding the first zero-byte by left shifting ~0ul based on the
position of the first zero byte.

Unfortunately, if the first (top) byte is zero, the output of
prep_zero_mask has only the top bit set, resulting in undefined C
behaviour as we shift left by an amount equal to the width of the type.
As it happens, GCC doesn't manage to spot this through the call to fls(),
but the issue remains if architectures choose to implement their shift
instructions differently.

An example would be arch/arm/ (AArch32), where LSL Rd, Rn, #32 results
in Rd == 0x0, whilst on arch/arm64 (AArch64) LSL Xd, Xn, #64 results in
Xd == Xn.

Rather than check explicitly for the problematic shift, this patch adds
an extra shift by 1, replacing fls with __fls. Since zero_bytemask is
never called with a zero argument (has_zero() is used to check the data
first), we don't need to worry about calling __fls(0), which is
undefined.

Cc: 
Cc: Victor Kamensky 
Signed-off-by: Will Deacon 
Signed-off-by: Linus Torvalds

mm: use paravirt friendly ops for NUMA hinting ptes

2014-04-18T23:40:09+00:00

David Vrabel identified a regression when using automatic NUMA balancing
under Xen whereby page table entries were getting corrupted due to the
use of native PTE operations.  Quoting him

	Xen PV guest page tables require that their entries use machine
	addresses if the preset bit (_PAGE_PRESENT) is set, and (for
	successful migration) non-present PTEs must use pseudo-physical
	addresses.  This is because on migration MFNs in present PTEs are
	translated to PFNs (canonicalised) so they may be translated back
	to the new MFN in the destination domain (uncanonicalised).

	pte_mknonnuma(), pmd_mknonnuma(), pte_mknuma() and pmd_mknuma()
	set and clear the _PAGE_PRESENT bit using pte_set_flags(),
	pte_clear_flags(), etc.

	In a Xen PV guest, these functions must translate MFNs to PFNs
	when clearing _PAGE_PRESENT and translate PFNs to MFNs when setting
	_PAGE_PRESENT.

His suggested fix converted p[te|md]_[set|clear]_flags to using
paravirt-friendly ops but this is overkill.  He suggested an alternative
of using p[te|md]_modify in the NUMA page table operations but this is
does more work than necessary and would require looking up a VMA for
protections.

This patch modifies the NUMA page table operations to use paravirt
friendly operations to set/clear the flags of interest.  Unfortunately
this will take a performance hit when updating the PTEs on
CONFIG_PARAVIRT but I do not see a way around it that does not break
Xen.

Signed-off-by: Mel Gorman 
Acked-by: David Vrabel 
Tested-by: David Vrabel 
Cc: Ingo Molnar 
Cc: Peter Anvin 
Cc: Fengguang Wu 
Cc: Linus Torvalds 
Cc: Steven Noonan 
Cc: Rik van Riel 
Cc: Peter Zijlstra 
Cc: Andrea Arcangeli 
Cc: Dave Hansen 
Cc: Srikar Dronamraju 
Cc: Cyrill Gorcunov 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'llvmlinux-for-v3.15' of git://git.linuxfoundation.org/llvmlinux/kernel

2014-04-13T00:00:40+00:00

Pull llvm patches from Behan Webster:
 "These are some initial updates to support compiling the kernel with
  clang.

  These patches have been through the proper reviews to the best of my
  ability, and have been soaking in linux-next for a few weeks.  These
  patches by themselves still do not completely allow clang to be used
  with the kernel code, but lay the foundation for other patches which
  are still under review.

  Several other of the LLVMLinux patches have been already added via
  maintainer trees"

* tag 'llvmlinux-for-v3.15' of git://git.linuxfoundation.org/llvmlinux/kernel:
  x86: LLVMLinux: Fix "incomplete type const struct x86cpu_device_id"
  x86 kbuild: LLVMLinux: More cc-options added for clang
  x86, acpi: LLVMLinux: Remove nested functions from Thinkpad ACPI
  LLVMLinux: Add support for clang to compiler.h and new compiler-clang.h
  LLVMLinux: Remove warning about returning an uninitialized variable
  kbuild: LLVMLinux: Fix LINUX_COMPILER definition script for compilation with clang
  Documentation: LLVMLinux: Update Documentation/dontdiff
  kbuild: LLVMLinux: Adapt warnings for compilation with clang
  kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang

Merge git://git.infradead.org/users/eparis/audit

2014-04-12T19:38:53+00:00

Pull audit updates from Eric Paris.

* git://git.infradead.org/users/eparis/audit: (28 commits)
  AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC
  audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range
  audit: do not cast audit_rule_data pointers pointlesly
  AUDIT: Allow login in non-init namespaces
  audit: define audit_is_compat in kernel internal header
  kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c
  sched: declare pid_alive as inline
  audit: use uapi/linux/audit.h for AUDIT_ARCH declarations
  syscall_get_arch: remove useless function arguments
  audit: remove stray newline from audit_log_execve_info() audit_panic() call
  audit: remove stray newlines from audit_log_lost messages
  audit: include subject in login records
  audit: remove superfluous new- prefix in AUDIT_LOGIN messages
  audit: allow user processes to log from another PID namespace
  audit: anchor all pid references in the initial pid namespace
  audit: convert PPIDs to the inital PID namespace.
  pid: get pid_t ppid of task in init_pid_ns
  audit: rename the misleading audit_get_context() to audit_take_context()
  audit: Add generic compat syscall support
  audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL
  ...

LLVMLinux: Remove warning about returning an uninitialized variable

2014-04-09T20:44:35+00:00

Fix uninitialized return code in default case in cmpxchg-local.h

This patch fixes the code to prevent an uninitialized return value that is detected
when compiling with clang. The bug produces numerous warnings when compiling the
Linux kernel with clang.

Signed-off-by: Behan Webster 
Signed-off-by: Mark Charlebois 
Acked-by: David Howells 
Acked-by: Arnd Bergmann

mm: create generic early_ioremap() support

2014-04-07T23:36:15+00:00

This patch creates a generic implementation of early_ioremap() support
based on the existing x86 implementation.  early_ioremp() is useful for
early boot code which needs to temporarily map I/O or memory regions
before normal mapping functions such as ioremap() are available.

Some architectures have optional MMU.  In the no-MMU case, the remap
functions simply return the passed in physical address and the unmap
functions do nothing.

Signed-off-by: Mark Salter 
Acked-by: Catalin Marinas 
Acked-by: H. Peter Anvin 
Cc: Borislav Petkov 
Cc: Dave Young 
Cc: Will Deacon 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

percpu: add raw_cpu_ops

2014-04-07T23:36:13+00:00

The kernel has never been audited to ensure that this_cpu operations are
consistently used throughout the kernel.  The code generated in many
places can be improved through the use of this_cpu operations (which
uses a segment register for relocation of per cpu offsets instead of
performing address calculations).

The patch set also addresses various consistency issues in general with
the per cpu macros.

A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only
   because checks are skipped. This is typically shown through a raw_
   prefix. So this patch set changes the places where __this_cpu_ptr()
   is used to raw_cpu_ptr().

B. There has been the long term wish by some that __this_cpu operations
   would check for preemption. However, there are cases where preemption
   checks need to be skipped. This patch set adds raw_cpu operations that
   do not check for preemption and then adds preemption checks to the
   __this_cpu operations.

C. The use of __get_cpu_var is always a reference to a percpu variable
   that can also be handled via a this_cpu operation. This patch set
   replaces all uses of __get_cpu_var with this_cpu operations.

D. We can then use this_cpu RMW operations in various places replacing
   sequences of instructions by a single one.

E. The use of this_cpu operations throughout will allow other arches than
   x86 to implement optimized references and RMV operations to work with
   per cpu local data.

F. The use of this_cpu operations opens up the possibility to
   further optimize code that relies on synchronization through
   per cpu data.

The patch set works in a couple of stages:

I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr().
    Also converts the existing __this_cpu_xx_# primitive in the x86
    code to raw_cpu_xx_#.

II. Patch 2-4 use the raw_cpu operations in places that would give
     us false positives once they are enabled.

III. Patch 5 adds preemption checks to __this_cpu operations to allow
    checking if preemption is properly disabled when these functions
    are used.

IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var
   with this_cpu_ptr. They do not depend on any changes to the percpu
   code. No preemption tests are skipped if they are applied.

V. Patches 21-46 are conversion patches that use this_cpu operations
   in various kernel subsystems/drivers or arch code.

VI.  Patches 47/48 (not included in this series) remove no longer used
    functions (__this_cpu_ptr and __get_cpu_var).  These should only be
    applied after all the conversion patches have made it and after we
    have done additional passes through the kernel to ensure that none of
    the uses of these functions remain.

This patch (of 46):

The patches following this one will add preemption checks to __this_cpu
ops so we need to have an alternative way to use this_cpu operations
without preemption checks.

raw_cpu_ops will be the basis for all other ops since these will be the
operations that do not implement any checks.

Primitive operations are renamed by this patch from __this_cpu_xxx to
raw_cpu_xxxx.

Also change the uses of the x86 percpu primitives in preempt.h.
These depend directly on asm/percpu.h (header #include nesting issue).

Signed-off-by: Peter Zijlstra 
Signed-off-by: Christoph Lameter 
Acked-by: Ingo Molnar 
Cc: Tejun Heo 
Cc: "James E.J. Bottomley" 
Cc: "Paul E. McKenney" 
Cc: Alex Shi 
Cc: Arnd Bergmann 
Cc: Benjamin Herrenschmidt 
Cc: Bryan Wu 
Cc: Catalin Marinas 
Cc: Chris Metcalf 
Cc: Daniel Lezcano 
Cc: David Daney 
Cc: David Miller 
Cc: David S. Miller 
Cc: Dimitri Sivanich 
Cc: Dipankar Sarma 
Cc: Eric Dumazet 
Cc: Fenghua Yu 
Cc: Frederic Weisbecker 
Cc: Greg Kroah-Hartman 
Cc: H. Peter Anvin 
Cc: Haavard Skinnemoen 
Cc: Hans-Christian Egtvedt 
Cc: Hedi Berriche 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Ivan Kokshaysky 
Cc: James Hogan 
Cc: Jens Axboe 
Cc: John Stultz 
Cc: Martin Schwidefsky 
Cc: Masami Hiramatsu 
Cc: Matt Turner 
Cc: Mike Frysinger 
Cc: Mike Travis 
Cc: Neil Brown 
Cc: Nicolas Pitre 
Cc: Paul Mackerras 
Cc: Paul Mundt 
Cc: Rafael J. Wysocki 
Cc: Ralf Baechle 
Cc: Richard Henderson 
Cc: Robert Richter 
Cc: Russell King 
Cc: Russell King 
Cc: Rusty Russell 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Will Deacon 
Cc: Wim Van Sebroeck 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds