[PATCHSET #upstream] libata: separate out SFF and BMDMA

[Tejun Heo <tj@kernel.org>]

Hello,

This is the first take of separate-out-SFF-and-BMDMA patchset.

Historically, ATA meant SFF (or TASKFILE interface) plus BMDMA and
that holds true for many modern SATA controllers.  This was reflected
in libata implementation and libata core layer and SFF/BMDMA support
used to be all tangled in one piece.

For SFF/BMDMA drivers, this assumption is fine but for drivers which
have native interfaces (e.g. ahci, sata_sil24), this meant that those
drivers had to emulate SFF/BMDMA to ceratin not-so-well defined level
libata core layer expects.  A lot of this vague dependency on
SFF/BMDMA was removed during recent SFF/BMDMA separation but there
still are SFF/BMDMA specific assumptions in libata core layer.

Another issue which surpassed with the addition of all the legacy,
platform and somewhat peculiar PATA drivers is that now there are
enough drivers which use SFF interface but use its own DMA interface
or don't support DMA at all.  This, in similar fashion, led those
drivers to fake certain level of BMDMA functionality to please the
libata SFF/BMDMA layer.  This led to the following interesting
solutions in low level drivers.

1. For BMDMA drivers which don't use traditional BMDMA register,
   ata_bmdma_mode_filter() incorrectly inhibits DMA modes.  Those
   drivers either have to inherit from ata_sff_port_ops or clear
   ->mode_filter explicitly.

2. non-BMDMA drivers call into BMDMA PRD table allocation.  It doesn't
   actually allocate PRD table if bmdma_addr is not initialized but is
   still confusing.

3. For BMDMA drivers which don't use traditional BMDMA register, some
   methods might not be invoked as expected (e.g. bmdma_stop from
   ata_sff_post_internal_cmd()).

4. SFF drivers w/ custom DMA interface implement noop BMDMA ops
   worrying libata core might call into one of them.

This patchset further separates SFF/BMDMA support from the rest of the
libata and separate out BMDMA from SFF.  This patchset contains the
following 22 patches.

 0001-pata_sch-use-ata_pci_sff_init_one.patch
 0002-sata_inic162x-inic162x-is-not-dependent-on-CONFIG_A.patch
 0003-sata_mv-remove-unnecessary-initialization.patch
 0004-libata-sff-clear-IRQ-from-ata_sff_error_handler-o.patch
 0005-libata-sff-kill-unused-prototype-and-make-ata_dev_s.patch
 0006-libata-kill-ATA_FLAG_DISABLED.patch
 0007-sata_inic162x-kill-PORT_PRD_ADDR-initialization.patch
 0008-libata-sff-reorder-SFF-BMDMA-functions.patch
 0009-pata_cmd640-bf54x-icside-fix-inheritance.patch
 0010-libata-sff-clean-up-BMDMA-initialization.patch
 0011-libata-sff-introduce-ata_sff_init-exit-and-ata_sf.patch
 0012-libata-sff-ap-last_-ctl-are-SFF-specific.patch
 0013-libata-sff-port_task-is-SFF-specific.patch
 0014-libata-sff-separate-out-BMDMA-EHs.patch
 0015-libata-sff-ata_sff_-dumb_-qc_prep-are-BMDMA-specifi.patch
 0016-libata-sff-prd-is-BMDMA-specific.patch
 0017-libata-sff-separate-out-BMDMA-qc_issue.patch
 0018-libata-sff-ata_sff_irq_clear-is-BMDMA-specific.patch
 0019-libata-sff-separate-out-BMDMA-irq-handler.patch
 0020-libata-sff-separate-out-BMDMA-init.patch
 0021-sata_qstor-kill-dummy-BMDMA-ops.patch
 0022-libata-sff-make-BMDMA-optional.patch

0001-0010 make things aligned for the future changes.

 0004 changes the default SFF error handler behavior such that
 unnecessary register accesses are removed.  I'm fairly sure this
 change is safe (tested on various SFF/BMDMA controllers) but we'll
 need to look out for problem reports.

 0006 kills ATA_FLAG_DISABLED (finally).  This patch touches SCSI SAS
 drivers.

 0010 cleans up BMDMA initialization and bmdma_addr condition checks.

0011-0013 further separate out SFF assumptions from libata core layer.

0014-0021 separate out BMDMA from SFF.

0022 makes BMDMA optional and reorganizes Kconfig options according to
the groups of drivers they belong to.

This patchset is on top of

  linus#master (2515ddc6db8eb49a79f0fe5e67ff09ac7c81eab4)
+ [1] libata-sff-fix-ata_sff_post_internal_cmd
+ [2] libata-initialize-port_task-when-!CONFIG_ATA_SFF
+ [3] libata-eh-fix-slave-link-EH-action-mask-handling
+ [4] libata-transfer-EHI-control-flags-to-slave-ehc_i

and makes the followings changes.

 drivers/ata/Kconfig                 |  360 +++----
 drivers/ata/Makefile                |   47 
 drivers/ata/ata_piix.c              |    4 
 drivers/ata/libata-core.c           |  172 ---
 drivers/ata/libata-eh.c             |   11 
 drivers/ata/libata-scsi.c           |    3 
 drivers/ata/libata-sff.c            | 1757 ++++++++++++++++++++----------------
 drivers/ata/libata.h                |   37 
 drivers/ata/pata_acpi.c             |   10 
 drivers/ata/pata_ali.c              |    7 
 drivers/ata/pata_amd.c              |    2 
 drivers/ata/pata_artop.c            |    2 
 drivers/ata/pata_atiixp.c           |    4 
 drivers/ata/pata_bf54x.c            |   20 
 drivers/ata/pata_cmd640.c           |   10 
 drivers/ata/pata_cmd64x.c           |    2 
 drivers/ata/pata_cs5520.c           |    4 
 drivers/ata/pata_cs5530.c           |    6 
 drivers/ata/pata_cs5535.c           |    2 
 drivers/ata/pata_cs5536.c           |    2 
 drivers/ata/pata_cypress.c          |    2 
 drivers/ata/pata_efar.c             |    2 
 drivers/ata/pata_hpt366.c           |    4 
 drivers/ata/pata_hpt37x.c           |    6 
 drivers/ata/pata_hpt3x2n.c          |    4 
 drivers/ata/pata_hpt3x3.c           |    2 
 drivers/ata/pata_icside.c           |    7 
 drivers/ata/pata_it8213.c           |    2 
 drivers/ata/pata_it821x.c           |    8 
 drivers/ata/pata_jmicron.c          |    2 
 drivers/ata/pata_marvell.c          |    2 
 drivers/ata/pata_mpc52xx.c          |    1 
 drivers/ata/pata_netcell.c          |    2 
 drivers/ata/pata_ninja32.c          |    2 
 drivers/ata/pata_ns87415.c          |    4 
 drivers/ata/pata_oldpiix.c          |    4 
 drivers/ata/pata_optidma.c          |    2 
 drivers/ata/pata_pdc2027x.c         |    6 
 drivers/ata/pata_pdc202xx_old.c     |    4 
 drivers/ata/pata_platform.c         |    1 
 drivers/ata/pata_radisys.c          |    4 
 drivers/ata/pata_sc1200.c           |    6 
 drivers/ata/pata_scc.c              |   15 
 drivers/ata/pata_sch.c              |   12 
 drivers/ata/pata_serverworks.c      |    8 
 drivers/ata/pata_sil680.c           |    4 
 drivers/ata/pata_sis.c              |    2 
 drivers/ata/pata_sl82c105.c         |    2 
 drivers/ata/pata_triflex.c          |    2 
 drivers/ata/pata_via.c              |    2 
 drivers/ata/pdc_adma.c              |   74 -
 drivers/ata/sata_inic162x.c         |   25 
 drivers/ata/sata_mv.c               |   15 
 drivers/ata/sata_nv.c               |  264 ++---
 drivers/ata/sata_promise.c          |   30 
 drivers/ata/sata_qstor.c            |  102 --
 drivers/ata/sata_sil.c              |    7 
 drivers/ata/sata_sil24.c            |    9 
 drivers/ata/sata_sis.c              |    4 
 drivers/ata/sata_svw.c              |    4 
 drivers/ata/sata_sx4.c              |    9 
 drivers/ata/sata_uli.c              |    6 
 drivers/ata/sata_via.c              |    6 
 drivers/ata/sata_vsc.c              |   12 
 drivers/scsi/ipr.c                  |    7 
 drivers/scsi/libsas/sas_scsi_host.c |    2 
 include/linux/ata.h                 |    2 
 include/linux/libata.h              |   91 +
 68 files changed, 1653 insertions(+), 1602 deletions(-)

Thanks.

--
tejun

[1] http://article.gmane.org/gmane.linux.ide/35364
[2] http://article.gmane.org/gmane.linux.ide/35363
[3] http://article.gmane.org/gmane.linux.ide/35390
[4] http://article.gmane.org/gmane.linux.ide/35393