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  1. 13 7月, 2014 3 次提交
  3. 07 7月, 2014 1 次提交
  5. 04 7月, 2014 1 次提交
  7. 30 6月, 2014 1 次提交
  9. 29 6月, 2014 1 次提交
    • T
      ARM: 8076/1: mm: add support for HW coherent systems in PL310 cache · 98ea2dba
      由 Thomas Petazzoni 提交于 
      When a PL310 cache is used on a system that provides hardware
coherency, the outer cache sync operation is useless, and can be
skipped. Moreover, on some systems, it is harmful as it causes
deadlocks between the Marvell coherency mechanism, the Marvell PCIe
controller and the Cortex-A9.

To avoid this, this commit introduces a new Device Tree property
'arm,io-coherent' for the L2 cache controller node, valid only for the
PL310 cache. It identifies the usage of the PL310 cache in an I/O
coherent configuration. Internally, it makes the driver disable the
outer cache sync operation.

Note that technically speaking, a fully coherent system wouldn't
require any of the other .outer_cache operations. However, in
practice, when booting secondary CPUs, these are not yet coherent, and
therefore a set of cache maintenance operations are necessary at this
point. This explains why we keep the other .outer_cache operations and
only ->sync is disabled.

While in theory any write to a PL310 register could cause the
deadlock, in practice, disabling ->sync is sufficient to workaround
the deadlock, since the other cache maintenance operations are only
used in very specific situations.

Contrary to previous versions of this patch, this new version does not
simply NULL-ify the ->sync member, because the l2c_init_data
structures are now 'const' and therefore cannot be modified, which is
a good thing. Therefore, this patch introduces a separate
l2c_init_data instance, called of_l2c310_coherent_data.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      98ea2dba
  11. 25 6月, 2014 3 次提交
  13. 24 6月, 2014 5 次提交
  15. 22 6月, 2014 1 次提交
    • A
      spi: qup: Remove chip select function · 4a8573ab
      由 Andy Gross 提交于 
      This patch removes the chip select function.  Chip select should instead be
supported using GPIOs, defining the DT entry "cs-gpios", and letting the SPI
core assert/deassert the chip select as it sees fit.

The chip select control inside the controller is buggy.  It is supposed to
automatically assert the chip select based on the activity in the controller,
but it is buggy and doesn't work at all.  So instead we elect to use GPIOs.
Signed-off-by: NAndy Gross <agross@codeaurora.org>
Signed-off-by: NMark Brown <broonie@linaro.org>
      4a8573ab
  17. 19 6月, 2014 2 次提交
  19. 17 6月, 2014 4 次提交
  21. 13 6月, 2014 2 次提交
  23. 12 6月, 2014 5 次提交
  25. 11 6月, 2014 5 次提交
  27. 10 6月, 2014 4 次提交
  29. 09 6月, 2014 1 次提交
  31. 07 6月, 2014 1 次提交
    • K
      mm: mark remap_file_pages() syscall as deprecated · 33041a0d
      由 Kirill A. Shutemov 提交于 
      The remap_file_pages() system call is used to create a nonlinear
mapping, that is, a mapping in which the pages of the file are mapped
into a nonsequential order in memory.  The advantage of using
remap_file_pages() over using repeated calls to mmap(2) is that the
former approach does not require the kernel to create additional VMA
(Virtual Memory Area) data structures.

Supporting of nonlinear mapping requires significant amount of
non-trivial code in kernel virtual memory subsystem including hot paths.
Also to get nonlinear mapping work kernel need a way to distinguish
normal page table entries from entries with file offset (pte_file).
Kernel reserves flag in PTE for this purpose.  PTE flags are scarce
resource especially on some CPU architectures.  It would be nice to free
up the flag for other usage.

Fortunately, there are not many users of remap_file_pages() in the wild.
It's only known that one enterprise RDBMS implementation uses the
syscall on 32-bit systems to map files bigger than can linearly fit into
32-bit virtual address space.  This use-case is not critical anymore
since 64-bit systems are widely available.

The plan is to deprecate the syscall and replace it with an emulation.
The emulation will create new VMAs instead of nonlinear mappings.  It's
going to work slower for rare users of remap_file_pages() but ABI is
preserved.

One side effect of emulation (apart from performance) is that user can
hit vm.max_map_count limit more easily due to additional VMAs.  See
comment for DEFAULT_MAX_MAP_COUNT for more details on the limit.

[akpm@linux-foundation.org: fix spello]
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Armin Rigo <arigo@tunes.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      33041a0d