1. 04 3月, 2008 1 次提交
  2. 24 2月, 2008 3 次提交
  3. 23 2月, 2008 11 次提交
  4. 22 2月, 2008 3 次提交
  5. 20 2月, 2008 1 次提交
  6. 19 2月, 2008 2 次提交
    • J
      libata: eliminate the home grown dma padding in favour of · dde20207
      James Bottomley 提交于
      that provided by the block layer
      
      ATA requires that all DMA transfers begin and end on word boundaries.
      Because of this, a large amount of machinery grew up in ide to adjust
      scatterlists on this basis.  However, as of 2.5, the block layer has a
      dma_alignment variable which ensures both the beginning and length of a
      DMA transfer are aligned on the dma_alignment boundary.  Although the
      block layer does adjust the beginning of the transfer to ensure this
      happens, it doesn't actually adjust the length, it merely makes sure
      that space is allocated for transfers beyond the declared length.  The
      upshot of this is that scatterlists may be padded to any size between
      the actual length and the length adjusted to the dma_alignment safely
      knowing that memory is allocated in this region.
      
      Right at the moment, SCSI takes the default dma_aligment which is on a
      512 byte boundary.  Note that this aligment only applies to transfers
      coming in from user space.  However, since all kernel allocations are
      automatically aligned on a minimum of 32 byte boundaries, it is safe to
      adjust them in this manner as well.
      
      tj: * Adjusting sg after padding is done in block layer.  Make libata
            set queue alignment correctly for ATAPI devices and drop broken
            sg mangling from ata_sg_setup().
          * Use request->raw_data_len for ATAPI transfer chunk size.
          * Killed qc->raw_nbytes.
          * Separated out killing qc->n_iter.
      Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
      Signed-off-by: NTejun Heo <htejun@gmail.com>
      Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      dde20207
    • T
      block: add request->raw_data_len · 6b00769f
      Tejun Heo 提交于
      With padding and draining moved into it, block layer now may extend
      requests as directed by queue parameters, so now a request has two
      sizes - the original request size and the extended size which matches
      the size of area pointed to by bios and later by sgs.  The latter size
      is what lower layers are primarily interested in when allocating,
      filling up DMA tables and setting up the controller.
      
      Both padding and draining extend the data area to accomodate
      controller characteristics.  As any controller which speaks SCSI can
      handle underflows, feeding larger data area is safe.
      
      So, this patch makes the primary data length field, request->data_len,
      indicate the size of full data area and add a separate length field,
      request->raw_data_len, for the unmodified request size.  The latter is
      used to report to higher layer (userland) and where the original
      request size should be fed to the controller or device.
      Signed-off-by: NTejun Heo <htejun@gmail.com>
      Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
      Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      6b00769f
  7. 18 2月, 2008 8 次提交
  8. 13 2月, 2008 3 次提交
  9. 12 2月, 2008 8 次提交