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  1. 29 5月, 2014 1 次提交
  3. 26 4月, 2014 1 次提交
    • L
      mm: split 'tlb_flush_mmu()' into tlb flushing and memory freeing parts · 1cf35d47
      由 Linus Torvalds 提交于 
      The mmu-gather operation 'tlb_flush_mmu()' has done two things: the
actual tlb flush operation, and the batched freeing of the pages that
the TLB entries pointed at.

This splits the operation into separate phases, so that the forced
batched flushing done by zap_pte_range() can now do the actual TLB flush
while still holding the page table lock, but delay the batched freeing
of all the pages to after the lock has been dropped.

This in turn allows us to avoid a race condition between
set_page_dirty() (as called by zap_pte_range() when it finds a dirty
shared memory pte) and page_mkclean(): because we now flush all the
dirty page data from the TLB's while holding the pte lock,
page_mkclean() will be held up walking the (recently cleaned) page
tables until after the TLB entries have been flushed from all CPU's.
Reported-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: NDave Hansen <dave.hansen@intel.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1cf35d47
  5. 25 4月, 2014 1 次提交
  7. 23 4月, 2014 3 次提交
  9. 09 4月, 2014 3 次提交
  11. 04 4月, 2014 1 次提交
    • R
      ARM: Better virt_to_page() handling · e26a9e00
      由 Russell King 提交于 
      virt_to_page() is incredibly inefficient when virt-to-phys patching is
enabled.  This is because we end up with this calculation:

  page = &mem_map[asm virt_to_phys(addr) >> 12 - __pv_phys_offset >> 12]

in assembly.  The asm virt_to_phys() is equivalent this this operation:

  addr - PAGE_OFFSET + __pv_phys_offset

and we can see that because this is assembly, the compiler has no chance
to optimise some of that away.  This should reduce down to:

  page = &mem_map[(addr - PAGE_OFFSET) >> 12]

for the common cases.  Permit the compiler to make this optimisation by
giving it more of the information it needs - do this by providing a
virt_to_pfn() macro.

Another issue which makes this more complex is that __pv_phys_offset is
a 64-bit type on all platforms.  This is needlessly wasteful - if we
store the physical offset as a PFN, we can save a lot of work having
to deal with 64-bit values, which sometimes ends up producing incredibly
horrid code:

     a4c:       e3009000        movw    r9, #0
                        a4c: R_ARM_MOVW_ABS_NC  __pv_phys_offset
     a50:       e3409000        movt    r9, #0          ; r9 = &__pv_phys_offset
                        a50: R_ARM_MOVT_ABS     __pv_phys_offset
     a54:       e3002000        movw    r2, #0
                        a54: R_ARM_MOVW_ABS_NC  __pv_phys_offset
     a58:       e3402000        movt    r2, #0          ; r2 = &__pv_phys_offset
                        a58: R_ARM_MOVT_ABS     __pv_phys_offset
     a5c:       e5999004        ldr     r9, [r9, #4]    ; r9 = high word of __pv_phys_offset
     a60:       e3001000        movw    r1, #0
                        a60: R_ARM_MOVW_ABS_NC  mem_map
     a64:       e592c000        ldr     ip, [r2]        ; ip = low word of __pv_phys_offset
Reviewed-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      e26a9e00
  13. 22 3月, 2014 2 次提交
  15. 20 3月, 2014 3 次提交
  17. 19 3月, 2014 8 次提交
  19. 18 3月, 2014 1 次提交
  21. 17 3月, 2014 1 次提交
  23. 12 3月, 2014 1 次提交
  25. 11 3月, 2014 1 次提交
  27. 08 3月, 2014 1 次提交
    • R
      ARM: fix noMMU kallsyms symbol filtering · 006fa259
      由 Russell King 提交于 
      With noMMU, CONFIG_PAGE_OFFSET was not being set correctly.  As there's
no MMU, PAGE_OFFSET should be equal to PHYS_OFFSET in all cases.  This
commit makes that explicit.

Since we do this, we don't need to mess around in asm/memory.h with
ifdefs to sort this out, so let's get rid of that, and there's no point
offering the "Memory split" option for noMMU as that's meaningless
there.

Fixes: b9b32bf7 ("ARM: use linker magic for vectors and vector stubs")
Cc: <stable@vger.kernel.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      006fa259
  29. 03 3月, 2014 7 次提交
  31. 28 2月, 2014 2 次提交
    • M
      arm: dma-mapping: remove order parameter from arm_iommu_create_mapping() · 68efd7d2
      由 Marek Szyprowski 提交于 
      The 'order' parameter for IOMMU-aware dma-mapping implementation was
introduced mainly as a hack to reduce size of the bitmap used for
tracking IO virtual address space. Since now it is possible to dynamically
resize the bitmap, this hack is not needed and can be removed without any
impact on the client devices. This way the parameters for
arm_iommu_create_mapping() becomes much easier to understand. 'size'
parameter now means the maximum supported IO address space size.

The code will allocate (resize) bitmap in chunks, ensuring that a single
chunk is not larger than a single memory page to avoid unreliable
allocations of size larger than PAGE_SIZE in atomic context.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
      68efd7d2
    • A
      arm: dma-mapping: Add support to extend DMA IOMMU mappings · 4d852ef8
      由 Andreas Herrmann 提交于 
      Instead of using just one bitmap to keep track of IO virtual addresses
(handed out for IOMMU use) introduce an array of bitmaps. This allows
us to extend existing mappings when running out of iova space in the
initial mapping etc.

If there is not enough space in the mapping to service an IO virtual
address allocation request, __alloc_iova() tries to extend the mapping
-- by allocating another bitmap -- and makes another allocation
attempt using the freshly allocated bitmap.

This allows arm iommu drivers to start with a decent initial size when
an dma_iommu_mapping is created and still to avoid running out of IO
virtual addresses for the mapping.
Signed-off-by: NAndreas Herrmann <andreas.herrmann@calxeda.com>
[mszyprow: removed extensions parameter to arm_iommu_create_mapping()
 function, which will be modified in the next patch anyway, also some
 debug messages about extending bitmap]
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
      4d852ef8
  33. 25 2月, 2014 3 次提交