1. 28 Apr, 2016 8 commits
  2. 26 Apr, 2016 8 commits
  3. 25 Apr, 2016 8 commits
  4. 21 Apr, 2016 2 commits
  5. 20 Apr, 2016 8 commits
  6. 19 Apr, 2016 4 commits
  7. 15 Apr, 2016 2 commits
    • Catalin Marinas's avatar
      arm64: Implement ptep_set_access_flags() for hardware AF/DBM · 66dbd6e6
      Catalin Marinas authored
      When hardware updates of the access and dirty states are enabled, the
      default ptep_set_access_flags() implementation based on calling
      set_pte_at() directly is potentially racy. This triggers the "racy dirty
      state clearing" warning in set_pte_at() because an existing writable PTE
      is overridden with a clean entry.
      
      There are two main scenarios for this situation:
      
      1. The CPU getting an access fault does not support hardware updates of
         the access/dirty flags. However, a different agent in the system
         (e.g. SMMU) can do this, therefore overriding a writable entry with a
         clean one could potentially lose the automatically updated dirty
         status
      
      2. A more complex situation is possible when all CPUs support hardware
         AF/DBM:
      
         a) Initial state: shareable + writable vma and pte_none(pte)
         b) Read fault taken by two threads of the same process on different
            CPUs
         c) CPU0 takes the mmap_sem and proceeds to handling the fault. It
            eventually reaches do_set_pte() which sets a writable + clean pte.
            CPU0 releases the mmap_sem
         d) CPU1 acquires the mmap_sem and proceeds to handle_pte_fault(). The
            pte entry it reads is present, writable and clean and it continues
            to pte_mkyoung()
         e) CPU1 calls ptep_set_access_flags()
      
         If between (d) and (e) the hardware (another CPU) updates the dirty
         state (clears PTE_RDONLY), CPU1 will override the PTR_RDONLY bit
         marking the entry clean again.
      
      This patch implements an arm64-specific ptep_set_access_flags() function
      to perform an atomic update of the PTE flags.
      
      Fixes: 2f4b829c
      
       ("arm64: Add support for hardware updates of the access and dirty pte bits")
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Reported-by: default avatarMing Lei <tom.leiming@gmail.com>
      Tested-by: default avatarJulien Grall <julien.grall@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: <stable@vger.kernel.org> # 4.3+
      [will: reworded comment]
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      66dbd6e6
    • Ganapatrao Kulkarni's avatar
      arm64, mm, numa: Add NUMA balancing support for arm64. · 56166230
      Ganapatrao Kulkarni authored
      
      
      Enable NUMA balancing for arm64 platforms.
      Add pte, pmd protnone helpers for use by automatic NUMA balancing.
      Reviewed-by: default avatarSteve Capper <steve.capper@arm.com>
      Reviewed-by: default avatarRobert Richter <rrichter@cavium.com>
      Signed-off-by: default avatarGanapatrao Kulkarni <gkulkarni@caviumnetworks.com>
      Signed-off-by: default avatarDavid Daney <david.daney@cavium.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      56166230