The function ata_sas_port_init() has always really done its own thing.
However, as a precursor to moving to the libata new eh, it has to be
properly using the standard libata scan paths.  This means separating
the current libata scan paths into pieces which can be shared with
libsas and pieces which cant (really just the async call and the host
scan).
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

In libata, the non-EH code paths should always take and release
ap->lock explicitly when accessing hardware or shared data structures.
However, once EH is active, it's assumed that the port is owned by EH
and EH methods don't explicitly take ap->lock unless race from irq
handler or other code paths are expected.  However, libata EH didn't
guarantee exclusion among EHs for ports of the same host.  IOW,
multiple EHs may execute in parallel on multiple ports of the same
controller.

In many cases, especially in SATA, the ports are completely
independent of each other and this doesn't cause problems; however,
there are cases where different ports share the same resource, which
lead to obscure timing related bugs such as the one fixed by commit
213373cf (ata_piix: fix locking around SIDPR access).

This patch implements exclusion among EHs of the same host.  When EH
begins, it acquires per-host EH ownership by calling ata_eh_acquire().
When EH finishes, the ownership is released by calling
ata_eh_release().  EH ownership is also released whenever the EH
thread goes to sleep from ata_msleep() or explicitly and reacquired
after waking up.

This ensures that while EH is actively accessing the hardware, it has
exclusive access to it while allowing EHs to interleave and progress
in parallel as they hit waiting stages, which dominate the time spent
in EH.  This achieves cross-port EH exclusion without pervasive and
fragile changes while still allowing parallel EH for the most part.

This was first reported by yuanding02@gmail.com more than three years
ago in the following bugzilla.  :-)

  https://bugzilla.kernel.org/show_bug.cgi?id=8223Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Reported-by: yuanding02@gmail.com
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Port multipliers can do DIPM on fan-out links fine.  Implement support
for it.  Tested w/ SIMG 57xx and marvell PMPs.  Both the host and
fan-out links enter power save modes nicely.

SIMG 37xx and 47xx report link offline on SStatus causing EH to detach
the devices.  Blacklisted.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

The current LPM implementation has the following issues.

* Operation order isn't well thought-out.  e.g. HIPM should be
  configured after IPM in SControl is properly configured.  Not the
  other way around.

* Suspend/resume paths call ata_lpm_enable/disable() which must only
  be called from EH context directly.  Also, ata_lpm_enable/disable()
  were called whether LPM was in use or not.

* Implementation is per-port when it should be per-link.  As a result,
  it can't be used for controllers with slave links or PMP.

* LPM state isn't managed consistently.  After a link reset for
  whatever reason including suspend/resume the actual LPM state would
  be reset leaving ap->lpm_policy inconsistent.

* Generic/driver-specific logic boundary isn't clear.  Currently,
  libahci has to mangle stuff which libata EH proper should be
  handling.  This makes the implementation unnecessarily complex and
  fragile.

* Tied to ALPM.  Doesn't consider DIPM only cases and doesn't check
  whether the device allows HIPM.

* Error handling isn't implemented.

Given the extent of mismatch with the rest of libata, I don't think
trying to fix it piecewise makes much sense.  This patch reimplements
LPM support.

* The new implementation is per-link.  The target policy is still
  port-wide (ap->target_lpm_policy) but all the mechanisms and states
  are per-link and integrate well with the rest of link abstraction
  and can work with slave and PMP links.

* Core EH has proper control of LPM state.  LPM state is reconfigured
  when and only when reconfiguration is necessary.  It makes sure that
  LPM state is reset when probing for new device on the link.
  Controller agnostic logic is now implemented in libata EH proper and
  driver implementation only has to deal with controller specifics.

* Proper error handling.  LPM config failure is attributed to the
  device on the link and LPM is disabled for the link if it fails
  repeatedly.

* ops->enable/disable_pm() are replaced with single ops->set_lpm()
  which takes @policy and @hints.  This simplifies driver specific
  implementation.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Link power management is about to be reimplemented.  Prepare for it.

* Implement sata_link_scr_lpm().

* Drop static from ata_dev_set_feature() and make it available to
  other libata files.

* Trivial whitespace adjustments.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Link power management related symbols are in confusing state w/ mixed
usages of lpm, ipm and pm.  This patch cleans up lpm related symbols
and sysfs show/store functions as follows.

* lpm states - NOT_AVAILABLE, MIN_POWER, MAX_PERFORMANCE and
  MEDIUM_POWER are renamed to ATA_LPM_UNKNOWN and
  ATA_LPM_{MIN|MAX|MED}_POWER.

* Pre/postfixes are unified to lpm.

* sysfs show/store functions for link_power_management_policy were
  curiously named get/put and unnecessarily complex.  Renamed to
  show/store and simplified.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

This is a scheleton for libata transport class.
All information is read only, exporting information from libata:
- ata_port class: one per ATA port
- ata_link class: one per ATA port or 15 for SATA Port Multiplier
- ata_device class: up to 2 for PATA link, usually one for SATA.
Signed-off-by: NGwendal Grignou <gwendal@google.com>
Reviewed-by: NGrant Grundler <grundler@google.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

libata has two concurrency related limitations.

a. ata_wq which is used for polling PIO has single thread per CPU.  If
   there are multiple devices doing polling PIO on the same CPU, they
   can't be executed simultaneously.

b. ata_aux_wq which is used for SCSI probing has single thread.  In
   cases where SCSI probing is stalled for extended period of time
   which is possible for ATAPI devices, this will stall all probing.

#a is solved by increasing maximum concurrency of ata_wq.  Please note
that polling PIO might be used under allocation path and thus needs to
be served by a separate wq with a rescuer.

#b is solved by using the default wq instead and achieving exclusion
via per-port mutex.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NJeff Garzik <jgarzik@pobox.com>

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: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

port_task is tightly bound to the standard SFF PIO HSM implementation.
Using it for any other purpose would be error-prone and there's no
such user and if some drivers need such feature, it would be much
better off using its own.  Move it inside CONFIG_ATA_SFF and rename it
to sff_pio_task.

The only function which is exposed to the core layer is
ata_sff_flush_pio_task() which is renamed from ata_port_flush_task()
and now also takes care of resetting hsm_task_state to HSM_ST_IDLE,
which is possible as it's now specific to PIO HSM.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

In preparation of proper SFF/BMDMA separation, introduce
ata_sff_init/exit() and ata_sff_port_init().  These functions
currently don't do anything.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

ata_irq_on() was renamed to ata_sff_irq_on() and exported a while ago
but prototype for the original function lingered in
drivers/ata/libata.h.  Kill it.  Also, ata_dev_select() is only used
inside drivers/ata/libata-sff.c.  Make it static.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Add ->gtf_filter to ata_device and set it to ata_acpi_gtf_filter when
initializing ata_link.  This is to allow quirks which apply different
gtf filters.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

This patch improve libata's output for error/notification messages
to allow easier comprehension and debugging:

When ATAPI commands issued through the SCSI layer fail, use SCSI
functions to print the CDB in human-readable form instead of just
dumping out the CDB in hex.

Print out the name of the failed command (as defined by the ATA
specification) in error handling output along with the raw register
contents.

When reporting status of ACPI taskfile commands executed on resume,
also output the names of the commands being executed (or not) in
readable form.

Since the extra data for printing command names increases kernel
size slightly, a config option has been added to allow disabling
command name output (as well as some of the error register parsing)
for those highly sensitive to kernel text size.
Signed-off-by: NRobert Hancock <hancockrwd@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Signed-off-by: NMark Lord <mlord@pobox.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Add @spd_limit to sata_down_spd_limit() so that the caller can specify
the SPD limit it wants.  This parameter doesn't get in the way even
when it's too low.  The closest possible limit is applied.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

ata_dev_disable() is about to be more tightly integrated into EH
logic.  Move it to libata-eh.c.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

This patch reverts the following three commits which convert libata to
use block layer tagging.

 43a49cbd
 e013e13b
 2fca5ccf

Although using block layer tagging is the right direction, due to the
tight coupling among tag number, data structure allocation and
hardware command slot allocation, libata doesn't work correctly with
the current conversion.

The biggest problem is guaranteeing that tag 0 is always used for
non-NCQ commands.  Due to the way blk-tag is implemented and how SCSI
starts and finishes requests, such guarantee can't be made.  I'm not
sure whether this would actually break any low level driver but it
doesn't look like a good idea to break such assumption given the
frailty of ATA controllers.

So, for the time being, keep using the old dumb in-libata qc
allocation.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Jens Axobe <jens.axboe@oracle.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

libata currently has a pretty dumb ATA_MAX_QUEUE loop for finding
a free tag to use. Instead of fixing that up, convert libata to
using block layer tagging - gets rid of code in libata, and is also
much faster.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.

Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.
Signed-off-by: NMike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Explanation taken from the comment of ata_slave_link_init().

 In libata, a port contains links and a link contains devices.  There
 is single host link but if a PMP is attached to it, there can be
 multiple fan-out links.  On SATA, there's usually a single device
 connected to a link but PATA and SATA controllers emulating TF based
 interface can have two - master and slave.

 However, there are a few controllers which don't fit into this
 abstraction too well - SATA controllers which emulate TF interface
 with both master and slave devices but also have separate SCR
 register sets for each device.  These controllers need separate links
 for physical link handling (e.g. onlineness, link speed) but should
 be treated like a traditional M/S controller for everything else
 (e.g. command issue, softreset).

 slave_link is libata's way of handling this class of controllers
 without impacting core layer too much.  For anything other than
 physical link handling, the default host link is used for both master
 and slave.  For physical link handling, separate @ap->slave_link is
 used.  All dirty details are implemented inside libata core layer.
 From LLD's POV, the only difference is that prereset, hardreset and
 postreset are called once more for the slave link, so the reset
 sequence looks like the following.

 prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
 softreset(M) -> postreset(M) -> postreset(S)

 Note that softreset is called only for the master.  Softreset resets
 both M/S by definition, so SRST on master should handle both (the
 standard method will work just fine).

As slave_link excludes PMP support and only code paths which deal with
the attributes of physical link are affected, all the changes are
localized to libata.h, libata-core.c and libata-eh.c.

 * ata_is_host_link() updated so that slave_link is considered as host
   link too.

 * iterator extended to iterate over the slave_link when using the
   underbarred version.

 * force param handling updated such that devno 16 is mapped to the
   slave link/device.

 * ata_link_on/offline() updated to return the combined result from
   master and slave link.  ata_phys_link_on/offline() are the direct
   versions.

 * EH autopsy and report are performed separately for master slave
   links.  Reset is udpated to implement the above described reset
   sequence.

Except for reset update, most changes are minor, many of them just
modifying dev->link to ata_dev_phys_link(dev) or using phys online
test instead.

After this update, LLDs can take full advantage of per-dev SCR
registers by simply turning on slave link.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Global and per-LLD ATAPI disable checks were done in the command issue
path probably because it was left out during EH conversion.  On
affected machines, this can cause lots of warning messages.  Move them
to where they belong - the probing path.

Reported by Chunbo Luo.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Chunbo Luo <chunbo.luo@windriver.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

ATA_TMOUT_INTERNAL which was 30secs were used for all internal
commands which is way too long when something goes wrong.  This patch
implements command type based stepped timeouts.  Different command
types can use different timeouts and each command type can use
different timeout values after timeouts.

ie. the initial timeout is set to a value which should cover most of
the cases but not too long so that run away cases don't delay things
too much.  After the first try times out, the second try can use
longer timeout and if that one times out too, it can go for full 30sec
timeout.

IDENTIFYs use 5s - 10s - 30s timeout and all other commands use 5s -
10s timeouts.

This patch significantly cuts down the needed time to handle failure
cases while still allowing libata to work with nut job devices through
retries.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

There's no reason to check whether to use DMA or not for no data
commands.  Don't do it.  While at it, make local variable using_pio in
atapi_xlat() set iff ATAPI_PROT_PIO is going to be used and rename
ata_check_atapi_dma() to atapi_check_dma() for consistency.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

* make ata_scsiop_*() static
* make ata_scsi_set_sense() static and move it above its users
* make ata_scsi_rbuf_fill() static
* kill unused ata_scsi_badcmd()
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

sata_set_spd_needed() can now become static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Make PMP support optional by adding CONFIG_SATA_PMP and leaving out
libata-pmp.c if it isn't set.  PMP helpers return constant values if
PMP support is not enabled and PMP declarations alias non-PMP
counterparts.  This makes the compiler to leave out PMP related part
out and LLDs to use non-PMP counterparts automatically.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Most of PMP support code is already in libata-pmp.c.  All that are in
libata-core.c are sata_pmp_port_ops and EXPORTs.  Move them to
libata-pmp.c.  Also, collect PMP related prototypes and declarations
in header files and move them right above of SFF stuff.

This change is to make PMP support optional.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Now that SFF support is completely separated out from the core layer,
it can be made optional.  Add CONFIG_ATA_SFF and let SFF drivers
depend on it.  If CONFIG_ATA_SFF isn't set, all codes in libata-sff.c
and data structures for SFF support are disabled.  This saves good
number of bytes for small systems.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Implement sata_std_hardreset(), which simply wraps around
sata_link_hardreset().  sata_std_hardreset() becomes new standard
hardreset method for sata_port_ops and sata_sff_hardreset() moves from
ata_base_port_ops to ata_sff_port_ops, which is where it really
belongs.

ata_is_builtin_hardreset() is added so that both
ata_std_error_handler() and ata_sff_error_handler() skip both builtin
hardresets if SCR isn't accessible.

piix_sidpr_hardreset() in ata_piix.c is identical to
sata_std_hardreset() in functionality and got replaced with the
standard function.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Factor out waiting logic (which is common to all ATA controllers) from
ata_sff_wait_ready() into ata_wait_ready().  ata_wait_ready() takes
@check_ready function pointer and uses it to poll for readiness.  This
allows non-SFF controllers to use ata_wait_ready() to wait for link
readiness.

This patch also implements ata_wait_after_reset() - generic version of
ata_sff_wait_after_reset() - using ata_wait_ready().

ata_sff_wait_ready() is reimplemented using ata_wait_ready() and
ata_sff_check_ready().  Functionality remains the same.
Signed-off-by: NTejun Heo <htejun@gmail.com>

ata_flush_code() hasn't been in use for quite some time now.  Kill it.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ata_tf_to_lba[48]() currently return LBA in tf + 1 for
ata_read_native_max_address().  Make them return LBA and make it
global so that it can be used to read LBA off TF for other purposes.
ata_read_native_max_address() now adds 1 itself.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

* Move SFF related functions from libata-core.c to libata-sff.c.

  ata_[bmdma_]sff_port_ops, ata_devchk(), ata_dev_try_classify(),
  ata_std_dev_select(), ata_tf_to_host(), ata_busy_sleep(),
  ata_wait_after_reset(), ata_wait_ready(), ata_bus_post_reset(),
  ata_bus_softreset(), ata_bus_reset(), ata_std_softreset(),
  sata_std_hardreset(), ata_fill_sg(), ata_fill_sg_dumb(),
  ata_qc_prep(), ata_dump_qc_prep(), ata_data_xfer(),
  ata_data_xfer_noirq(), ata_pio_sector(), ata_pio_sectors(),
  atapi_send_cdb(), __atapi_pio_bytes(), atapi_pio_bytes(),
  ata_hsm_ok_in_wq(), ata_hsm_qc_complete(), ata_hsm_move(),
  ata_pio_task(), ata_qc_issue_prot(), ata_host_intr(),
  ata_interrupt(), ata_std_ports()

* Make ata_pio_queue_task() global as it's now called from
  libata-sff.c.

* Move SFF related stuff in include/linux/libata.h and
  drivers/ata/libata.h into one place.  While at it, move timing
  constants into the global enum definition and fortify comments a
  bit.

This patch strictly moves stuff around and as such doesn't cause any
functional difference.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

atapi_dmadir can now become static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch implements libata.force module parameter which can
selectively override ATA port, link and device configurations
including cable type, SATA PHY SPD limit, transfer mode and NCQ.

For example, you can say "use 1.5Gbps for all fan-out ports attached
to the second port but allow 3.0Gbps for the PMP device itself, oh,
the device attached to the third fan-out port chokes on NCQ and
shouldn't go over UDMA4" by the following.

 libata.force=2:1.5g,2.15:3.0g,2.03:noncq,udma4
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Move ata_set_mode() to libata-eh.c.  ata_set_mode() is surely an EH
action and will be more tightly coupled with the rest of error
handling.  Move it to libata-eh.c.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ACPI spec (ver 3.0a, p289) requires IDE power on/off executes ACPI _PSx
methods. As recently most PATA drivers use libata, this patch adds _PSx
method support in libata. ACPI spec doesn't mention if SATA requires the
same _PSx method.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Acked-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Historically word 48 in the identify data was used to mean 32bit I/O
was supported for VLB IDE etc. ATA8 reassigns this word to the Trusted
Computing Group, where it is used for TCG features. This means that
an ATA8 TCG drive is going to trigger 32bit I/O on some systems which
will be funny.

Anyway we need to sort this out ready for ATA8 so:
- Reorder the ata.h header a bit so the ata_version function occurs early
  in it
- Make dword_io check the ATA version
- Add an ATA8 version checking TCG presence test

While we are at it the current drafts have a flaw where it may not be
possible to disable TCG features at boot (and opt out of the trusted
model) as TCG intends because it relies on presence of a different
optional feature (DCS). Handle this in software by refusing the TCG
commands if libata.allow_tpm is not set. (We must make it possible
as some environments such as proprietary VDR devices will doubtless
want to use it to lock up content)

Finally as with CPRM print a warning so that the user knows they may
not be able to full access and use the device.
Signed-off-by: NAlan Cox <alan@redhat.com>

Add two hooks - ata_acpi_dissociate() which is called during driver
detach after the whole host is shutdown and ata_acpi_on_disable()
which is called when a device is disabled.
Signed-off-by: NTejun heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>