24 Aug, 2020

1 commit

  • Replace the existing /* fall through */ comments and its variants with
    the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
    fall-through markings when it is the case.

    [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

    Signed-off-by: Gustavo A. R. Silva

    Gustavo A. R. Silva
     

27 Mar, 2020

1 commit


01 Nov, 2019

1 commit

  • In case a driver wants to return an error from qc_prep, return enum
    ata_completion_errors. sata_mv is one of those drivers -- see the next
    patch. Other drivers return the newly defined AC_ERR_OK.

    [v2] use enum ata_completion_errors and AC_ERR_OK.

    Signed-off-by: Jiri Slaby
    Cc: Jens Axboe
    Cc: linux-ide@vger.kernel.org
    Signed-off-by: Jens Axboe

    Jiri Slaby
     

27 Aug, 2019

1 commit


21 May, 2019

1 commit

  • Based on 1 normalized pattern(s):

    this program is free software you can redistribute it and or modify
    it under the terms of the gnu general public license as published by
    the free software foundation either version 2 or at your option any
    later version this program is distributed in the hope that it will
    be useful but without any warranty without even the implied warranty
    of merchantability or fitness for a particular purpose see the gnu
    general public license for more details you should have received a
    copy of the gnu general public license along with this program see
    the file copying if not write to the free software foundation 675
    mass ave cambridge ma 02139 usa

    extracted by the scancode license scanner the SPDX license identifier

    GPL-2.0-or-later

    has been chosen to replace the boilerplate/reference in 52 file(s).

    Signed-off-by: Thomas Gleixner
    Reviewed-by: Jilayne Lovejoy
    Reviewed-by: Steve Winslow
    Reviewed-by: Kate Stewart
    Reviewed-by: Allison Randal
    Cc: linux-spdx@vger.kernel.org
    Link: https://lkml.kernel.org/r/20190519154042.342335923@linutronix.de
    Signed-off-by: Greg Kroah-Hartman

    Thomas Gleixner
     

16 May, 2017

1 commit


08 Apr, 2015

1 commit

  • Replace occurences of the pci api by appropriate call to the dma api.

    A simplified version of the semantic patch that finds this problem is as
    follows: (http://coccinelle.lip6.fr)

    @deprecated@
    idexpression id;
    position p;
    @@

    (
    pci_dma_supported@p ( id, ...)
    |
    pci_alloc_consistent@p ( id, ...)
    )

    @bad1@
    idexpression id;
    position deprecated.p;
    @@
    ...when != &id->dev
    when != pci_get_drvdata ( id )
    when != pci_enable_device ( id )
    (
    pci_dma_supported@p ( id, ...)
    |
    pci_alloc_consistent@p ( id, ...)
    )

    @depends on !bad1@
    idexpression id;
    expression direction;
    position deprecated.p;
    @@

    (
    - pci_dma_supported@p ( id,
    + dma_supported ( &id->dev,
    ...
    + , GFP_ATOMIC
    )
    |
    - pci_alloc_consistent@p ( id,
    + dma_alloc_coherent ( &id->dev,
    ...
    + , GFP_ATOMIC
    )
    )

    Signed-off-by: Quentin Lambert
    Signed-off-by: Tejun Heo

    Quentin Lambert
     

14 Feb, 2014

1 commit


26 Sep, 2013

1 commit


15 May, 2013

1 commit


29 Nov, 2012

1 commit

  • sata_promise's pdc_hard_reset_port() needs to serialize because it
    flips a port-specific bit in controller register that's shared by
    all ports. The code takes the ata host lock for this, but that's
    broken because an interrupt may arrive on our irq during the hard
    reset sequence, and that too will take the ata host lock. With
    lockdep enabled a big nasty warning is seen.

    Fixed by adding private state to the ata host structure, containing
    a second lock used only for serializing the hard reset sequences.
    This eliminated the lockdep warnings both on my test rig and on
    the original reporter's machine.

    Signed-off-by: Mikael Pettersson
    Tested-by: Adko Branil
    Cc: stable@vger.kernel.org
    Signed-off-by: Jeff Garzik

    Mikael Pettersson
     

26 Jul, 2012

1 commit

  • This patch converts the drivers in drivers/ata/* to use module_pci_driver()
    macro which makes the code smaller and a bit simpler.

    Signed-off-by: Axel Lin
    Cc: Alan Cox
    Cc: Jeff Garzik
    Cc: Mikael Pettersson
    Cc: Mark Lord
    Cc: Jeremy Higdon
    Cc: Benjamin Herrenschmidt
    Signed-off-by: Jeff Garzik

    Axel Lin
     

24 Jul, 2011

2 commits

  • Use a single mechanism to show driver version.
    Reduces text a tiny bit too.

    Remove uses of static int printed_version
    Add and use ata_print_version(const struct device *, const char *ver)
    and ata_print_version_once.

    $ size drivers/ata/built-in.*
    text data bss dec hex filename
    544969 73893 116584 735446 b38d6 drivers/ata/built-in.allyesconfig.ata.o
    543870 73893 116592 734355 b34ad drivers/ata/built-in.allyesconfig.print_once.o
    141328 14689 4220 160237 271ed drivers/ata/built-in.defconfig.ata.o
    141212 14689 4220 160121 27179 drivers/ata/built-in.defconfig.print_once.o

    Signed-off-by: Joe Perches
    Signed-off-by: Jeff Garzik

    Joe Perches
     
  • Saves a bit of text as the call takes fewer args.

    Coalesce a few formats.
    Convert a few bare printks to pr_cont.

    $ size drivers/ata/built-in.o*
    text data bss dec hex filename
    558429 73893 117864 750186 b726a drivers/ata/built-in.o.allyesconfig.new
    559574 73893 117888 751355 b76fb drivers/ata/built-in.o.allyesconfig.old
    149567 14689 4220 168476 2921c drivers/ata/built-in.o.defconfig.new
    149851 14689 4220 168760 29338 drivers/ata/built-in.o.defconfig.old

    Signed-off-by: Joe Perches
    Signed-off-by: Jeff Garzik

    Joe Perches
     

02 Mar, 2011

2 commits

  • All checks of ATA_FLAG_NO_LEGACY have been removed by the commits
    c791c30670ea61f19eec390124128bf278e854fe ([libata] minor PCI IDE probe
    fixes and cleanups) and f0d36efdc624beb3d9e29b9ab9e9537bf0f25d5b (libata:
    update libata core layer to use devres), so I think it's time to finally
    get rid of this flag...

    Signed-off-by: Sergei Shtylyov
    Signed-off-by: Jeff Garzik

    Sergei Shtylyov
     
  • Commit 0d5ff566779f894ca9937231a181eb31e4adff0e (libata: convert to iomap)
    removed all checks of ATA_FLAG_MMIO but neglected to remove the flag itself.
    Do it now, at last...

    Signed-off-by: Sergei Shtylyov
    Signed-off-by: Jeff Garzik

    Sergei Shtylyov
     

20 May, 2010

3 commits

  • struct ata_prd and ap->prd are BMDMA specific. Add bmdma_ prefix to
    them and move them inside CONFIG_ATA_SFF.

    Signed-off-by: Tejun Heo
    Signed-off-by: Jeff Garzik

    Tejun Heo
     
  • Some of error handling logic in ata_sff_error_handler() and all of
    ata_sff_post_internal_cmd() are for BMDMA. Create
    ata_bmdma_error_handler() and ata_bmdma_post_internal_cmd() and move
    BMDMA part into those.

    While at it, change DMA protocol check to ata_is_dma(), fix
    post_internal_cmd to call ap->ops->bmdma_stop instead of directly
    calling ata_bmdma_stop() and open code hardreset selection so that
    ata_std_error_handler() doesn't have to know about sff hardreset.

    As these two functions are BMDMA specific, there's no reason to check
    for bmdma_addr before calling bmdma methods if the protocol of the
    failed command is DMA. sata_mv and pata_mpc52xx now don't need to set
    .post_internal_cmd to ATA_OP_NULL and pata_icside and sata_qstor don't
    need to set it to their bmdma_stop routines.

    ata_sff_post_internal_cmd() becomes noop and is removed.

    This fixes p3 described in clean-up-BMDMA-initialization patch.

    Signed-off-by: Tejun Heo
    Signed-off-by: Jeff Garzik

    Tejun Heo
     
  • When BMDMA initialization failed or BMDMA was not available for
    whatever reason, bmdma_addr was left at zero and used as an indication
    that BMDMA shouldn't be used. This leads to the following problems.

    p1. 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.

    p2. 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.

    p3. 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()).

    p4. SFF drivers w/ custom DMA interface implement noop BMDMA ops
    worrying libata core might call into one of them.

    These problems are caused by the muddy line between SFF and BMDMA and
    the assumption that all BMDMA controllers initialize bmdma_addr.

    This patch fixes p1 and p2 by removing the bmdma_addr assumption and
    moving prd allocation to BMDMA port start. Later patches will fix the
    remaining issues.

    This patch improves BMDMA initialization such that

    * When BMDMA register initialization fails, falls back to PIO instead
    of failing. ata_pci_bmdma_init() never fails now.

    * When ata_pci_bmdma_init() falls back to PIO, it clears
    ap->mwdma_mask and udma_mask instead of depending on
    ata_bmdma_mode_filter(). This makes ata_bmdma_mode_filter()
    unnecessary thus resolving p1.

    * ata_port_start() which actually is BMDMA specific is moved to
    ata_bmdma_port_start(). ata_port_start() and ata_sff_port_start()
    are killed.

    * ata_sff_port_start32() is moved and renamed to
    ata_bmdma_port_start32().

    Drivers which no longer call into PRD table allocation are...

    pdc_adma, sata_inic162x, sata_qstor, sata_sx4, pata_cmd640 and all
    drivers which inherit from ata_sff_port_ops.

    pata_icside sets ->port_start to ATA_OP_NULL as it doesn't need PRD
    but is a BMDMA controller and doesn't have custom port_start like
    other such controllers.

    Note that with the previous patch which makes all and only BMDMA
    drivers inherit from ata_bmdma_port_ops, this change doesn't break
    drivers which need PRD table.

    Signed-off-by: Tejun Heo
    Signed-off-by: Jeff Garzik

    Tejun Heo
     

18 May, 2010

1 commit

  • ATA_FLAG_DISABLED is only used by drivers which don't use
    ->error_handler framework and is largely broken. Its only meaningful
    function is to make irq handlers skip processing if the flag is set,
    which is largely useless and even harmful as it makes those ports more
    likely to cause IRQ storms.

    Kill ATA_FLAG_DISABLED and makes the callers disable attached devices
    instead. ata_port_probe() and ata_port_disable() which manipulate the
    flag are also killed.

    This simplifies condition check in IRQ handlers. While updating IRQ
    handlers, remove ap NULL check as libata guarantees consecutive port
    allocation (unoccupied ports are initialized with dummies) and
    long-obsolete ATA_QCFLAG_ACTIVE check (checked by ata_qc_from_tag()).

    Signed-off-by: Tejun Heo
    Signed-off-by: Jeff Garzik

    Tejun Heo
     

30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

13 Jan, 2010

1 commit

  • When sata_promise encounters an overrun or underrun error it
    translates that to a libata AC_ERR_HSM, causing a hard reset.
    Since over/under-runs were thought to be rare and transient,
    this action seemed reasonable.

    Unfortunately it turns out that the controller throws overrun
    errors when e.g. hal polls a CD or DVD writer containing blank
    media, causing long sequences of hard resets and retries before
    EH finally gives up.

    This patch updates sata_promise to classify over/under-runs as
    AC_ERR_OTHER instead. This allows libata EH and upper layers to
    retry or fail the operation as they see fit without the disruption
    caused by repeated hard resets.

    This fixes a problem using a DVD-RAM drive with sata_promise,
    reported by Thomas Schorpp. I also tested it on a DVD-RW drive.

    Signed-off-by: Mikael Pettersson
    Tested-by: thomas schorpp
    Signed-off-by: Jeff Garzik

    Mikael Pettersson
     

18 Sep, 2009

2 commits

  • sata_promise's reset code has deviated quite a bit from
    the Promise reference driver's, and it has been observed
    to fail to recover from errors in some cases.

    This patch thus updates the reset code to more closely
    match the reference driver:

    - soft reset (pdc_reset_port):
    * wait for ATA engine to not be in packet command mode
    (2nd gen only)
    * write reset bit in PDC_CTLSTAT before the first read
    in the loop
    * for 2nd gen SATA follow up with FPDMA reset and clearing
    error status registers
    - hard reset (pdc_sata_hardreset):
    * wait for ATA engine to not be in packet command mode
    (2nd gen only)
    * reset ATA engine via the PCI control register
    * Tejun's change to use non-waiting hardreset + follow-up SRST

    I'm not changing the hotplug mask bits since they are taken care
    of by sata_promise's ->freeze() and ->thaw() operations. And I'm
    not writing the PMP port # because that's always zero (for now).

    Tested here on various controllers. In particular, one disk
    which used to timeout and fail to recover from certain hdparm
    and smartmonctl commands now works nicely.

    Signed-off-by: Mikael Pettersson
    Signed-off-by: Jeff Garzik

    Mikael Pettersson
     
  • 1st generation Promise SATA chips are prone to generating spurious
    hotplug events which can disrupt normal operation. This has been
    observed on 20376 and 20378 chips. This patch thus disables hotplug
    support on 1st gen chips while leaving it enabled for 2nd gen chips.

    The pdc_sata_hotplug_offset() function becomes redundant so it is
    removed.

    Tested on 1st gen 20376 and 20378 mainboard chips and on a 2nd gen
    SATA300 PCI card.

    Signed-off-by: Mikael Pettersson
    Tested-by: Kurt Roeckx
    Signed-off-by: Jeff Garzik

    Mikael Pettersson
     

25 Mar, 2009

2 commits


04 Nov, 2008

1 commit

  • Promise ATA engines need to be reset when errors occur.
    That's currently done for errors detected by sata_promise itself,
    but it's not done for errors like timeouts detected outside of
    the low-level driver.

    The effect of this omission is that a timeout tends to result
    in a sequence of failed COMRESETs after which libata EH gives
    up and disables the port. At that point the port's ATA engine
    hangs and even reloading the driver will not resume it.

    To fix this, make sata_promise override ->hardreset on SATA
    ports with code which calls pdc_reset_port() on the port in
    question before calling libata's hardreset. PATA ports don't
    use ->hardreset, so for those we override ->softreset instead.

    Signed-off-by: Mikael Pettersson
    Signed-off-by: Jeff Garzik

    Mikael Pettersson
     

29 Sep, 2008

1 commit

  • Logically, SCR access ops should take @link; however, there was no
    compelling reason to convert all SCR access ops when adding @link
    abstraction as there's one-to-one mapping between a port and a non-PMP
    link. However, that assumption won't hold anymore with the scheduled
    addition of slave link.

    Make SCR access ops per-link.

    Signed-off-by: Tejun Heo
    Signed-off-by: Jeff Garzik

    Tejun Heo
     

20 May, 2008

3 commits

  • Minor coding-style fixes for sata_promise:
    - remove stray blank lines
    - fix checkpatch.pl errors; warnings about long lines
    remain, but I don't intend to address those at this time
    - remove two inline directives: neither is essential and
    both functions are trivially inlinable anyway by virtue
    of being static and having a single unique call site
    - fix comment in pdc_interrupt(): the bits in PDC_INT_SEQMASK
    denote SEQIDs not tags, the distinction becomes important
    when NCQ gets implemented

    Signed-off-by: Mikael Pettersson
    Signed-off-by: Jeff Garzik

    Mikael Pettersson
     
  • This patch cleans up sata_promise's mmio accesses.

    In sata_promise there are three distinct mmio address spaces:
    1. global registers, offsets from host->iomap[PDC_MMIO_BAR]
    2. per-port ATA registers, offsets from ap->ioaddr.cmd_addr
    3. per-port SATA registers, offsets from ap->ioaddr.scr_addr

    The driver currently often fails to indicate which address space
    a given mmio base pointer refers to, which is a source of bugs
    and confusion (see recent pdc_thaw() irq clearing bug; it's also
    been an obstacle for the pending NCQ extensions).

    To reduce these problems, adopt a coding style where the name of
    a base pointer always indicates which address space it refers to:
    1. global registers: host_mmio
    2. per-port ATA registers: ata_mmio
    3. per-port SATA registers: sata_mmio

    Also rearrange register offset definitions to clearly indicate
    which address space they belong to, and add a symbolic definition
    for the previously hard-coded PHYMODE4 register.

    Signed-off-by: Mikael Pettersson
    Signed-off-by: Jeff Garzik

    Mikael Pettersson
     
  • This patch fixes two bugs in sata_promise's irq status clearing paths:
    1. When clearing the irq status for a specific port, the driver
    read the global SEQMASK register. This is wrong because that
    clears the irq status for _all_ ports.
    2. pdc_thaw() incorrectly added the PDC_INT_SEQMASK host register
    offset to a per-port ata engine base address. This resulted in
    it reading the unrelated PDC_PKT_SUBMIT register, which did not
    have the desired irq status clearing effect.

    In both cases the fix is to read from the port's Command/Status
    register. This also matches what Promise's own driver does.

    Signed-off-by: Mikael Pettersson
    Signed-off-by: Jeff Garzik

    Mikael Pettersson
     

18 Apr, 2008

6 commits

  • Add sff_ prefix to SFF specific port ops.

    This rename is in preparation of separating SFF support out of libata
    core layer. This patch strictly renames ops and doesn't introduce any
    behavior difference.

    Signed-off-by: Tejun Heo

    Tejun Heo
     
  • SFF functions have confusing names. Some have sff prefix, some have
    bmdma, some std, some pci and some none. Unify the naming by...

    * SFF functions which are common to both BMDMA and non-BMDMA are
    prefixed with ata_sff_.

    * SFF functions which are specific to BMDMA are prefixed with
    ata_bmdma_.

    * SFF functions which are specific to PCI but apply to both BMDMA and
    non-BMDMA are prefixed with ata_pci_sff_.

    * SFF functions which are specific to PCI and BMDMA are prefixed with
    ata_pci_bmdma_.

    * Drop generic prefixes from LLD specific routines. For example,
    bfin_std_dev_select -> bfin_dev_select.

    The following renames are noteworthy.

    ata_qc_issue_prot() -> ata_sff_qc_issue()
    ata_pci_default_filter() -> ata_bmdma_mode_filter()
    ata_dev_try_classify() -> ata_sff_dev_classify()

    This rename is in preparation of separating SFF support out of libata
    core layer. This patch strictly renames functions and doesn't
    introduce any behavior difference.

    Signed-off-by: Tejun Heo

    Tejun Heo
     
  • Signed-off-by: Al Viro
    Signed-off-by: Jeff Garzik

    Al Viro
     
  • Currently reset methods are not specified directly in the
    ata_port_operations table. If a LLD wants to use custom reset
    methods, it should construct and use a error_handler which uses those
    reset methods. It's done this way for two reasons.

    First, the ops table already contained too many methods and adding
    four more of them would noticeably increase the amount of necessary
    boilerplate code all over low level drivers.

    Second, as ->error_handler uses those reset methods, it can get
    confusing. ie. By overriding ->error_handler, those reset ops can be
    made useless making layering a bit hazy.

    Now that ops table uses inheritance, the first problem doesn't exist
    anymore. The second isn't completely solved but is relieved by
    providing default values - most drivers can just override what it has
    implemented and don't have to concern itself about higher level
    callbacks. In fact, there currently is no driver which actually
    modifies error handling behavior. Drivers which override
    ->error_handler just wraps the standard error handler only to prepare
    the controller for EH. I don't think making ops layering strict has
    any noticeable benefit.

    This patch makes ->prereset, ->softreset, ->hardreset, ->postreset and
    their PMP counterparts propoer ops. Default ops are provided in the
    base ops tables and drivers are converted to override individual reset
    methods instead of creating custom error_handler.

    * ata_std_error_handler() doesn't use sata_std_hardreset() if SCRs
    aren't accessible. sata_promise doesn't need to use separate
    error_handlers for PATA and SATA anymore.

    * softreset is broken for sata_inic162x and sata_sx4. As libata now
    always prefers hardreset, this doesn't really matter but the ops are
    forced to NULL using ATA_OP_NULL for documentation purpose.

    * pata_hpt374 needs to use different prereset for the first and second
    PCI functions. This used to be done by branching from
    hpt374_error_handler(). The proper way to do this is to use
    separate ops and port_info tables for each function. Converted.

    Signed-off-by: Tejun Heo

    Tejun Heo
     
  • libata lets low level drivers build ata_port_operations table and
    register it with libata core layer. This allows low level drivers
    high level of flexibility but also burdens them with lots of
    boilerplate entries.

    This becomes worse for drivers which support related similar
    controllers which differ slightly. They share most of the operations
    except for a few. However, the driver still needs to list all
    operations for each variant. This results in large number of
    duplicate entries, which is not only inefficient but also error-prone
    as it becomes very difficult to tell what the actual differences are.

    This duplicate boilerplates all over the low level drivers also make
    updating the core layer exteremely difficult and error-prone. When
    compounded with multi-branched development model, it ends up
    accumulating inconsistencies over time. Some of those inconsistencies
    cause immediate problems and fixed. Others just remain there dormant
    making maintenance increasingly difficult.

    To rectify the problem, this patch implements ata_port_operations
    inheritance. To allow LLDs to easily re-use their own ops tables
    overriding only specific methods, this patch implements poor man's
    class inheritance. An ops table has ->inherits field which can be set
    to any ops table as long as it doesn't create a loop. When the host
    is started, the inheritance chain is followed and any operation which
    isn't specified is taken from the nearest ancestor which has it
    specified. This operation is called finalization and done only once
    per an ops table and the LLD doesn't have to do anything special about
    it other than making the ops table non-const such that libata can
    update it.

    libata provides four base ops tables lower drivers can inherit from -
    base, sata, pmp, sff and bmdma. To avoid overriding these ops
    accidentaly, these ops are declared const and LLDs should always
    inherit these instead of using them directly.

    After finalization, all the ops table are identical before and after
    the patch except for setting .irq_handler to ata_interrupt in drivers
    which didn't use to. The .irq_handler doesn't have any actual effect
    and the field will soon be removed by later patch.

    * sata_sx4 is still using old style EH and currently doesn't take
    advantage of ops inheritance.

    Signed-off-by: Tejun Heo

    Tejun Heo
     
  • libata lets low level drivers build scsi_host_template and register it
    to the SCSI layer. This allows low level drivers high level of
    flexibility but also burdens them with lots of boilerplate entries.

    This patch implements SHT initializers which can be used to initialize
    all the boilerplate entries in a sht. Three variants of them are
    implemented - BASE, BMDMA and NCQ - for different types of drivers.
    Note that entries can be overriden by putting individual initializers
    after the helper macro.

    All sht tables are identical before and after this patch.

    Signed-off-by: Tejun Heo

    Tejun Heo
     

25 Mar, 2008

1 commit

  • A Promise SATA controller will signal hotplug events when a hard
    reset (COMRESET) is done on a port. These events aren't masked by
    the driver, and the unexpected interrupts will cause a sequence
    of failed reset attempts util libata's EH finally gives up.

    This has not been a common problem so far, but the pending libata
    hardreset-by-default changes makes it a critical issue.

    The solution is to disable hotplug events before a reset, and to
    reenable them afterwards. (Promise's driver does this too.)

    This patch adds SATA-specific versions of ->freeze() and ->thaw()
    that also disable and enable hotplug events. PATA ports continue
    to use the old versions of ->freeze() and ->thaw().

    Accesses to the hotplug register must be serialised via host->lock.
    We rely on ap->lock == &ap->host->lock and that libata takes this
    lock before ->freeze() and ->thaw(). Document this requirement.
    The interrupt handler is adjusted so its hotplug register accesses
    are inside the region protected by host->lock.

    Tested on various chips (SATA300TX4, SATA300TX2plus, SATAII150TX4,
    FastTrack TX4000) with various combinations of SATA and PATA disks,
    with and without the pending hardreset-by-default changes.

    Signed-off-by: Mikael Pettersson
    Acked-by: Tejun Heo
    Signed-off-by: Jeff Garzik

    Mikael Pettersson
     

16 Feb, 2008

1 commit


23 Jan, 2008

1 commit

  • libata used private sg iterator to handle padding sg. Now that sg can
    be chained, padding can be handled using standard sg ops. Convert to
    chained sg.

    * s/qc->__sg/qc->sg/

    * s/qc->pad_sgent/qc->extra_sg[]/. Because chaining consumes one sg
    entry. There need to be two extra sg entries. The renaming is also
    for future addition of other extra sg entries.

    * Padding setup is moved into ata_sg_setup_extra() which is organized
    in a way that future addition of other extra sg entries is easy.

    * qc->orig_n_elem is unused and removed.

    * qc->n_elem now contains the number of sg entries that LLDs should
    map. qc->mapped_n_elem is added to carry the original number of
    mapped sgs for unmapping.

    * The last sg of the original sg list is used to chain to extra sg
    list. The original last sg is pointed to by qc->last_sg and the
    content is stored in qc->saved_last_sg. It's restored during
    ata_sg_clean().

    * All sg walking code has been updated. Unnecessary assertions and
    checks for conditions the core layer already guarantees are removed.

    Signed-off-by: Tejun Heo
    Cc: Jens Axboe
    Signed-off-by: Jeff Garzik

    Tejun Heo