1. 01 2月, 2018 1 次提交
  2. 20 12月, 2017 5 次提交
    • R
      powerpc: Swizzle around 4K PTE bits to free up bit 5 and bit 6 · 273b4936
      Ram Pai 提交于
      We need PTE bits 3 ,4, 5, 6 and 57 to support protection-keys,
      because these are the bits we want to consolidate on across all
      configuration to support protection keys.
      
      Bit 3,4,5 and 6 are currently used on 4K-pte kernels. But bit 9
      and 10 are available. Hence we use the two available bits and
      free up bit 5 and 6. We will still not be able to free up bit 3
      and 4. In the absence of any other free bits, we will have to
      stay satisfied with what we have :-(. This means we will not
      be able to support 32 protection keys, but only 8. The bit
      numbers are big-endian as defined in the ISA3.0
      
      This patch does the following change to 4K PTE.
      
      H_PAGE_F_SECOND (S) which occupied bit 4 moves to bit 7.
      H_PAGE_F_GIX (G,I,X) which occupied bit 5, 6 and 7 also moves
      to bit 8,9, 10 respectively.
      H_PAGE_HASHPTE (H) which occupied bit 8 moves to bit 4.
      
      Before the patch, the 4k PTE format was as follows
      
       0 1 2 3 4  5  6  7  8 9 10....................57.....63
       : : : : :  :  :  :  : : :                      :     :
       v v v v v  v  v  v  v v v                      v     v
      ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-,
      |x|x|x|B|S |G |I |X |H| | |x|x|................| |x|x|x|
      '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_'
      
      After the patch, the 4k PTE format is as follows
      
       0 1 2 3 4  5  6  7  8 9 10....................57.....63
       : : : : :  :  :  :  : : :                      :     :
       v v v v v  v  v  v  v v v                      v     v
      ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-,
      |x|x|x|B|H |  |  |S |G|I|X|x|x|................| |.|.|.|
      '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_'
      
      The patch has no code changes; just swizzles around bits.
      Signed-off-by: NRam Pai <linuxram@us.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      273b4936
    • R
      powerpc: shifted-by-one hidx value · 7b84947c
      Ram Pai 提交于
      0xf is considered invalid hidx value. It indicates absence of a backing
      HPTE. A PTE is initialized to 0xf either
      a) when it is new it is newly allocated to hold 4k-backing-HPTE
      	or
      b) Any time it gets demoted to a 4k-backing-HPTE
      
      This patch shifts the representation by one-modulo-0xf; i.e hidx 0 is
      represented as 1, 1 as 2,... , and 0xf as 0. This convention lets us
      initialize the secondary-part of the PTE to all zeroes. PTEs are anyway
      zero'd when allocated. We do not have to zero them again; thus saving on
      the initialization.
      Signed-off-by: NRam Pai <linuxram@us.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      7b84947c
    • R
      powerpc: Free up four 64K PTE bits in 64K backed HPTE pages · bf9a95f9
      Ram Pai 提交于
      Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6
      in the 64K backed HPTE pages. This along with the earlier
      patch will entirely free up the four bits from 64K PTE.
      The bit numbers are big-endian as defined in the ISA3.0
      
      This patch does the following change to 64K PTE backed
      by 64K HPTE.
      
      H_PAGE_F_SECOND (S) which occupied bit 4 moves to the
      	second part of the pte to bit 60.
      H_PAGE_F_GIX (G,I,X) which occupied bit 5, 6 and 7 also
      	moves to the second part of the pte to bit 61,
       	62, 63, 64 respectively
      
      since bit 7 is now freed up, we move H_PAGE_BUSY (B) from
      bit 9 to bit 7.
      
      The second part of the PTE will hold
      (H_PAGE_F_SECOND|H_PAGE_F_GIX) at bit 60,61,62,63.
      NOTE: None of the bits in the secondary PTE were not used
      by 64k-HPTE backed PTE.
      
      Before the patch, the 64K HPTE backed 64k PTE format was
      as follows
      
       0 1 2 3 4  5  6  7  8 9 10...........................63
       : : : : :  :  :  :  : : :                            :
       v v v v v  v  v  v  v v v                            v
      
      ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-,
      |x|x|x| |S |G |I |X |x|B| |x|x|................|x|x|x|x| <- primary pte
      '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_'
      | | | | |  |  |  |  | | | | |..................| | | | | <- secondary pte
      '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_'
      
      After the patch, the 64k HPTE backed 64k PTE format is
      as follows
      
       0 1 2 3 4  5  6  7  8 9 10...........................63
       : : : : :  :  :  :  : : :                            :
       v v v v v  v  v  v  v v v                            v
      
      ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-,
      |x|x|x| |  |  |  |B |x| | |x|x|................|.|.|.|.| <- primary pte
      '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_'
      | | | | |  |  |  |  | | | | |..................|S|G|I|X| <- secondary pte
      '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_'
      
      The above PTE changes is applicable to hugetlbpages aswell.
      
      The patch does the following code changes:
      
      a) moves the H_PAGE_F_SECOND and H_PAGE_F_GIX to 4k PTE
      	header since it is no more needed b the 64k PTEs.
      b) abstracts out __real_pte() and __rpte_to_hidx() so the
      	caller need not know the bit location of the slot.
      c) moves the slot bits to the secondary pte.
      Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: NRam Pai <linuxram@us.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      bf9a95f9
    • R
      powerpc: Free up four 64K PTE bits in 4K backed HPTE pages · 9d2edb18
      Ram Pai 提交于
      Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6,
      in the 4K backed HPTE pages.These bits continue to be used
      for 64K backed HPTE pages in this patch, but will be freed
      up in the next patch. The bit numbers are big-endian as
      defined in the ISA3.0
      
      The patch does the following change to the 4k HTPE backed
      64K PTE's format.
      
      H_PAGE_BUSY moves from bit 3 to bit 9 (B bit in the figure
      		below)
      V0 which occupied bit 4 is not used anymore.
      V1 which occupied bit 5 is not used anymore.
      V2 which occupied bit 6 is not used anymore.
      V3 which occupied bit 7 is not used anymore.
      
      Before the patch, the 4k backed 64k PTE format was as follows
      
       0 1 2 3 4  5  6  7  8 9 10...........................63
       : : : : :  :  :  :  : : :                            :
       v v v v v  v  v  v  v v v                            v
      
      ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-,
      |x|x|x|B|V0|V1|V2|V3|x| | |x|x|................|x|x|x|x| <- primary pte
      '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_'
      |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte
      '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_'
      
      After the patch, the 4k backed 64k PTE format is as follows
      
       0 1 2 3 4  5  6  7  8 9 10...........................63
       : : : : :  :  :  :  : : :                            :
       v v v v v  v  v  v  v v v                            v
      
      ,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-,
      |x|x|x| |  |  |  |  |x|B| |x|x|................|.|.|.|.| <- primary pte
      '_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_'
      |S|G|I|X|S |G |I |X |S|G|I|X|..................|S|G|I|X| <- secondary pte
      '_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_'
      
      the four bits S,G,I,X (one quadruplet per 4k HPTE) that
      cache the hash-bucket slot value, is initialized to
      1,1,1,1 indicating -- an invalid slot. If a HPTE gets
      cached in a 1111 slot(i.e 7th slot of secondary hash
      bucket), it is released immediately. In other words,
      even though 1111 is a valid slot value in the hash
      bucket, we consider it invalid and release the slot and
      the HPTE. This gives us the opportunity to determine
      the validity of S,G,I,X bits based on its contents and
      not on any of the bits V0,V1,V2 or V3 in the primary PTE
      
      When we release a HPTE cached in the 1111 slot
      we also release a legitimate slot in the primary
      hash bucket and unmap its corresponding HPTE. This
      is to ensure that we do get a HPTE cached in a slot
      of the primary hash bucket, the next time we retry.
      
      Though treating 1111 slot as invalid, reduces the
      number of available slots in the hash bucket and may
      have an effect on the performance, the probabilty of
      hitting a 1111 slot is extermely low.
      
      Compared to the current scheme, the above scheme
      reduces the number of false hash table updates
      significantly and has the added advantage of releasing
      four valuable PTE bits for other purpose.
      
      NOTE:even though bits 3, 4, 5, 6, 7 are not used when
      the 64K PTE is backed by 4k HPTE, they continue to be
      used if the PTE gets backed by 64k HPTE. The next
      patch will decouple that aswell, and truely release the
      bits.
      
      This idea was jointly developed by Paul Mackerras,
      Aneesh, Michael Ellermen and myself.
      
      4K PTE format remains unchanged currently.
      
      The patch does the following code changes
      a) PTE flags are split between 64k and 4k header files.
      b) __hash_page_4K() is reimplemented to reflect the
       above logic.
      Acked-by: NBalbir Singh <bsingharora@gmail.com>
      Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: NRam Pai <linuxram@us.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      9d2edb18
    • R
      powerpc: introduce pte_set_hidx() helper · 59aa31fd
      Ram Pai 提交于
      Introduce pte_set_hidx().It sets the (H_PAGE_F_SECOND|H_PAGE_F_GIX) bits
      at the appropriate location in the PTE of 4K PTE. For 64K PTE, it sets
      the bits in the second part of the PTE. Though the implementation for
      the former just needs the slot parameter, it does take some additional
      parameters to keep the prototype consistent.
      
      This function will be handy as we work towards re-arranging the bits in
      the subsequent patches.
      Acked-by: NBalbir Singh <bsingharora@gmail.com>
      Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: NRam Pai <linuxram@us.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      59aa31fd
  3. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  4. 09 5月, 2017 1 次提交
    • M
      powerpc/mm/book3s/64: Rework page table geometry for lower memory usage · ba95b5d0
      Michael Ellerman 提交于
      Recently in commit f6eedbba ("powerpc/mm/hash: Increase VA range to 128TB")
      we increased the virtual address space for user processes to 128TB by default,
      and up to 512TB if user space opts in.
      
      This obviously required expanding the range of the Linux page tables. For Book3s
      64-bit using hash and with PAGE_SIZE=64K, we increased the PGD to 2^15 entries.
      This meant we could cover the full address range, while still being able to
      insert a 16G hugepage at the PGD level and a 16M hugepage in the PMD.
      
      The downside of that geometry is that it uses a lot of memory for the PGD, and
      in particular makes the PGD a 4-page allocation, which means it's much more
      likely to fail under memory pressure.
      
      Instead we can make the PMD larger, so that a single PUD entry maps 16G,
      allowing the 16G hugepages to sit at that level in the tree. We're then able to
      split the remaining bits between the PUG and PGD. We make the PGD slightly
      larger as that results in lower memory usage for typical programs.
      
      When THP is enabled the PMD actually doubles in size, to 2^11 entries, or 2^14
      bytes, which is large but still < PAGE_SIZE.
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      Reviewed-by: NBalbir Singh <bsingharora@gmail.com>
      Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      ba95b5d0
  5. 31 3月, 2017 3 次提交
  6. 18 11月, 2016 1 次提交
  7. 11 5月, 2016 2 次提交
  8. 01 5月, 2016 7 次提交
  9. 03 3月, 2016 1 次提交
  10. 29 2月, 2016 2 次提交
  11. 27 2月, 2016 1 次提交
    • P
      powerpc/mm/book3s-64: Free up 7 high-order bits in the Linux PTE · f1a9ae03
      Paul Mackerras 提交于
      This frees up bits 57-63 in the Linux PTE on 64-bit Book 3S machines.
      In the 4k page case, this is done just by reducing the size of the
      RPN field to 39 bits, giving 51-bit real addresses.  In the 64k page
      case, we had 10 unused bits in the middle of the PTE, so this moves
      the RPN field down 10 bits to make use of those unused bits.  This
      means the RPN field is now 3 bits larger at 37 bits, giving 53-bit
      real addresses in the normal case, or 49-bit real addresses for the
      special 4k PFN case.
      
      We are doing this in order to be able to move some other PTE bits
      into the positions where PowerISA V3.0 processors will expect to
      find them in radix-tree mode.  Ultimately we will be able to move
      the RPN field to lower bit positions and make it larger.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      f1a9ae03
  12. 16 1月, 2016 1 次提交
  13. 17 12月, 2015 1 次提交
    • L
      powerpc/mm: Add page soft dirty tracking · 7207f436
      Laurent Dufour 提交于
      User space checkpoint and restart tool (CRIU) needs the page's change
      to be soft tracked. This allows to do a pre checkpoint and then dump
      only touched pages.
      
      This is done by using a newly assigned PTE bit (_PAGE_SOFT_DIRTY) when
      the page is backed in memory, and a new _PAGE_SWP_SOFT_DIRTY bit when
      the page is swapped out.
      
      To introduce a new PTE _PAGE_SOFT_DIRTY bit value common to hash 4k
      and hash 64k pte, the bits already defined in hash-*4k.h should be
      shifted left by one.
      
      The _PAGE_SWP_SOFT_DIRTY bit is dynamically put after the swap type in
      the swap pte. A check is added to ensure that the bit is not
      overwritten by _PAGE_HPTEFLAGS.
      Signed-off-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
      CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      7207f436
  14. 14 12月, 2015 10 次提交
  15. 13 8月, 2014 1 次提交
  16. 05 8月, 2014 1 次提交
  17. 14 5月, 2013 1 次提交
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