Traditional IDE interface sucks in that it doesn't have a reliable IRQ
pending bit, so if the controller raises IRQ while the driver is
expecting it not to, the IRQ won't be cleared and eventually the IRQ
line will be killed by interrupt subsystem.  Some controllers have
non-standard mechanism to indicate IRQ pending so that this condition
can be detected and worked around.

This patch adds an optional operation ->sff_irq_check() which will be
called for each port from the ata_sff_interrupt() if an unexpected
interrupt is received.  If the operation returns %true,
->sff_check_status() and ->sff_irq_clear() will be cleared for the
port.  Note that this doesn't mark the interrupt as handled so it
won't prevent IRQ subsystem from killing the IRQ if this mechanism
fails to clear the spurious IRQ.

This patch also implements ->sff_irq_check() for ata_piix.  Note that
this adds slight overhead to shared IRQ operation as IRQs which are
destined for other controllers will trigger extra register accesses to
check whether IDE interrupt is pending but this solves rare screaming
IRQ cases and for some curious reason also helps weird BIOS related
glitch on Samsung n130 as reported in bko#14314.

  http://bugzilla.kernel.org/show_bug.cgi?id=14314

* piix_base_ops dropped as suggested by Sergei.

* Spurious IRQ detection doesn't kick in anymore if polling qc is in
  progress.  This provides less protection but some controllers have
  possible data corruption issues if the wrong register is accessed
  while a command is in progress.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NJohannes Stezenbach <js@sig21.net>
Reported-by: NHans Werner <hwerner4@gmx.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

host->ports[i] is never NULL if i < host->n_ports and non-NULL return
from ata_qc_from_tag() guarantees that the returned qc is active.
Drop unnecessary tests.

Superflous () dropped as suggested by Sergei.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

flush_dcache_page() must be called after (!ATA_TFLAG_WRITE) the
data copying to avoid D-cache aliasing with user space or I-D cache
coherency issues (when reading data from an ATA device using PIO,
the kernel dirties the D-cache but there is no flush_dcache_page()
required on Harvard architectures).
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

When we drain data from a device to clear DRQ during error recovery,
the number of bytes reported as drained is too low by a factor of 2
because the count is actually reporting the number of words drained,
not bytes. Fix this.
Signed-off-by: NRobert Hancock <hancockrwd@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

In libata-sff, ata_sff_post_internal_cmd() directly calls ata_bmdma_stop()
instead of ap->ops->bmdma_stop(). This can be a problem for controllers
that use their own bmdma_stop for which the generic sff one isn't suitable
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NJeff Garzik <jgarzik@redhat.com>

Comment spelling fixes and whitespace adjustment.
Signed-off-by: NKrzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

In libata-sff, ata_sff_post_internal_cmd() directly calls ata_bmdma_stop()
instead of ap->ops->bmdma_stop(). This can be a problem for controllers
that use their own bmdma_stop for which the generic sff one isn't suitable
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Handling of the trailing byte in ata_sff_data_xfer() is suboptimal bacause:

- it always initializes the padding buffer to 0 which is not really needed in
  both the read and write cases;

- it has to use memcpy() to transfer a single byte from/to the padding buffer;

- it uses io{read|write}16() accessors which swap bytes on the big endian CPUs
  and so have to additionally convert the data from/to the little endian format
  instead of using io{read|write}16_rep() accessors which are not supposed to
  change the byte ordering.
Signed-off-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

The legacy old IDE ioctl API for this is a bit primitive so we try
and map stuff sensibly onto it.

- Set PIO over DMA devices to report 32bit
- Add ability to change the PIO32 settings if the controller permits it
- Add that functionality into the sff drivers
- Add that functionality into the VLB legacy driver
- Turn on the 32bit PIO on the ninja32 and add support there
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

On a timeout call a device specific handler early in the recovery so that
we can complete and process successful commands which timed out due to IRQ
loss or the like rather more elegantly.

[Revised to exclude the timeout handling on a few devices that inherit from
 SFF but are not SFF enough to use the default timeout handler]
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

If the device is signalling that there is data to drain after an error we
should read the bytes out and throw them away. Without this some devices
and controllers get wedged and don't recover.

Based on earlier work by Mark Lord
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

libata keeps a shadow copy of the ATA CTL register (which is write only),
and only writes to the hardware when the required value doesn't match
the shadow. However this copy wasn't being maintained when performing
reset functions. This could cause problems for the first operation after
a reset when the correct value might not be written to the CTL register.

This problem was observed when hotplugging a drive: the identify command
was being issued with interrupts enabled, when they should have been
disabled.
Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Commit 871af121 (libata: Add 32bit
PIO support) has caused all kinds of errors on the ATAPI devices, so
it has been empirically proven that one shouldn't try to read/write
an extra data word when a device is not expecting it already. "Don't
do it then"; however, still use a chance to do 32-bit read/write one
last time when there are exactly 3 trailing bytes.

Oh, and stop pointlessly swapping the bytes to and fro on big-endian
machines by using io*_rep() accessors which shouldn't byte-swap.

This patch should fix the kernel.org bug #12609.
Signed-off-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Asus Pundit-R with atiixp controller has the second port missing and,
very unusually, its status is stuck at 0x7f and all others at 0.  This
meanst that it fails TF access test but gets detected as a disk due to
classification code check and then evades polling IDENTIFY presence
detection thanks to the missing BSY in the status value causing
excessive delays during boot.

This patch makes libata-sff HSM set NODEV_HINT if the status is 0x7f
to make polling IDENTIFY presence detection work for these machines.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

The EH message for NODEV_HINT path was describing the opposite
condition.  Fix it.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

This patch fixes a wrong WARN_ON that was triggered by 32bit PIO support:
WARNING: at drivers/ata/libata-sff.c:1017 ata_sff_hsm_move+0x45e/0x750()

__atapi_pio_bytes simply doesnt know enough to decide if there is a bug.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Convert WARN_ON() on command issue/completion paths to WARN_ON_ONCE()
so that libata doesn't spam the machine even when one of those
conditions triggers repeatedly.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

This matters for some controllers and in one or two cases almost doubles
PIO performance. Add a bmdma32 operations set we can inherit and activate
it for some controllers
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Currently libata uses four methods to detect device presence.

1. PHY status if available.
2. TF register R/W test (only promotes presence, never demotes)
3. device signature after reset
4. IDENTIFY failure detection in SFF state machine

Combination of the above works well in most cases but recently there
have been a few reports where a phantom device causes unnecessary
delay during probe.  In both cases, PHY status wasn't available.  In
one case, it passed #2 and #3 and failed IDENTIFY with ATA_ERR which
didn't qualify as #4.  The other failed #2 but as it passed #3 and #4,
it still caused failure.

In both cases, phantom device reported diagnostic failure, so these
cases can be safely worked around by considering any !ATA_DRQ IDENTIFY
failure as NODEV_HINT if diagnostic failure is set.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

ata_sff_post_internal_cmd() needs to grab port lock before calling
ata_bmdma_stop() and also need to clear hsm_task_state.  Fix it.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

On HSM_ST_ERR, ata_hsm_move() triggers WARN_ON() if AC_ERR_DEV or
AC_ERR_HSM is not set.  PHY events may trigger HSM_ST_ERR with other
error codes and, with or without it, there just isn't much reason to
do WARN_ON() on it.  Even if error code is not set there, core EH
logic won't have any problem dealing with the error condition.

OSDL bz#11065 reports this problem.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

libata has been using mix of jiffies and msecs for time druations.
This is getting confusing.  As writing sub HZ values in jiffies is
PITA and msecs_to_jiffies() can't be used as initializer, unify unit
for all time durations to msecs.  So, durations are in msecs and
deadlines are in jiffies.  ata_deadline() is added to compute deadline
from a start time and duration in msecs.

While at it, drop now superflous _msec suffix from arguments and
rename @timeout to @deadline if it represents a fixed point in time
rather than duration.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Improve SFF HSM violation reporting such that each HSM violation can
be distinguished using ehi_desc.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Fix G5 SATA irq 18: nobody cared, reported on -rc5 by Olaf Hering:
fixlet to a57c1bad libata-sff:
Fix oops reported in kerneloops.org for pnp devices with no ctl
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Acked-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Tested-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- Make ata_sff_altstatus private so nobody uses it by mistake
- Drop the 400nS delay from it

Add

ata_sff_irq_status	-	encapsulates the IRQ check logic

This function keeps the existing behaviour for altstatus using devices. I
actually suspect the logic was wrong before the changes but -rc isn't the
time to play with that

ata_sff_sync		-	ensure writes hit the device

Really we want an io* operation for 'is posted' eg ioisposted(ioaddr) so
that we can fix the nasty delay this causes on most systems.

- ata_sff_pause		-	400nS delay

Ensure the command hit the device and delay 400nS

- ata_sff_dma_pause

Ensure the I/O hit the device and enforce an HDMA1:0 transition delay.
Requires altstatus register exists, BUG if not so we don't risk
corruption in MWDMA modes. (UDMA the checksum will save your backside in
theory)

The only other complication then is devices with their own handlers.
rb532 can use dma_pause but scc needs to access its own altstatus
register for internal errata workarounds so directly call the drivers own
altstatus function.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Some controllers (jmb and inic162x) use 0x77 and 0x7f to indicate that
the device isn't ready yet.  It looks like they use 0xff if device
presence is detected but connection isn't established.  0x77 or 0x7f
after connection is established and use the value from signature FIS
after receiving it.

This patch implements ata_check_ready(), which takes TF status value
and determines whether the port is ready or not considering the above
and other conditions, and use it in @check_ready() functions.  This is
safe as both 0x77 and 0x7f aren't valid ready status value even though
they have BSY bit cleared.

This fixes hot plug detection failures which can be triggered with
certain drives if they aren't already spun up when the data connector
is hot plugged.

Tested on sil, sil24, ahci (jmb/ich), piix and inic162x combined with
eight drives from all major vendors.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

WARN_ON()'s in ata_hsm_move() was too liberal and got triggerred when
it shouldn't (e.g. hotplug events at the right moment).  As the HSM
only deals with device errors and state machine violations, make it
check only against them.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Mark Lord <liml@rtr.ca>
Cc: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Currently, SATA softresets should do link onlineness check before
actually performing SRST protocol but it doesn't really belong to
softreset.

This patch moves onlineness check in softreset to ata_eh_reset() and
ata_eh_followup_srst_needed() to clean up code and help future sata_mv
changes which need clear separation between SCR and TF accesses.

sata_fsl is peculiar in that its softreset really isn't softreset but
combination of hardreset and softreset.  This patch adds dummy private
->prereset to keep the current behavior but the driver really should
implement separate hard and soft resets and return -EAGAIN from
hardreset if it should be follwed by softreset.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Now that all SFF stuff is separated out of core layer, core layer
doesn't call ops->tf_read directly.  It gets called only via
ops->qc_fill_rtf() for non-SFF drivers.  This patch directly
implements private ops->qc_fill_rtf() for non-SFF controllers and kill
ops->tf_read().

This is much cleaner for non-SFF controllers as some of them have to
cache SFF register values in private data structure and report the
cached values via ops->tf_read().  Also, ops->tf_read() gets nasty for
controllers which don't have clear notion of TF registers when
operation is not in progress.

As this change makes default ops->qc_fill_rtf unnecessary, move
ata_sff_qc_fill_rtf() form ata_base_port_ops to ata_sff_port_ops where
it belongs.
Signed-off-by: NTejun Heo <htejun@gmail.com>

On command completion, ata_qc_complete() directly called ops->tf_read
to fill qc->result_tf.  This patch adds ops->qc_fill_rtf to replace
hardcoded ops->tf_read usage.

ata_sff_qc_fill_rtf() which uses ops->tf_read to fill result_tf is
implemented and set in ata_base_port_ops and other ops tables which
don't inherit from ata_base_port_ops, so this patch doesn't introduce
any behavior change.

ops->qc_fill_rtf() is similar to ops->sff_tf_read() but can only be
called when a command finishes.  As some non-SFF controllers don't
have TF registers defined unless they're associated with in-flight
commands, this limited operation makes life easier for those drivers
and help lifting SFF assumptions from libata core layer.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Previously, there were two ways to trigger follow-up SRST from
hardreset method - returning -EAGAIN and leaving all device classes
unmodified.  Drivers never used the latter mechanism and the only use
case for the former was when hardreset couldn't classify.

Drop the latter mechanism and let -EAGAIN mean "perform follow-up SRST
if classification is required".  This change removes unnecessary
follow-up SRSTs and simplifies reset implementations.
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>

sata_sff_hardreset() contains link readiness wait logic which isn't
SFF specific.  Move that part into sata_link_hardreset(), which now
takes two more parameters - @online and @check_ready.  Both are
optional.  The former is out parameter for link onlineness after
reset.  The latter is used to wait for link readiness after hardreset.

Users of sata_link_hardreset() is updated to use new funtionality and
ahci_hardreset() is updated to use sata_link_hardreset() instead of
sata_sff_hardreset().  This doesn't really cause any behavior change.
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>

Previously, post-softreset readiness is waited as follows.

1. ata_sff_wait_after_reset() waits for 150ms and then for
   ATA_TMOUT_FF_WAIT if status is 0xff and other conditions meet.

2. ata_bus_softreset() finishes with -ENODEV if status is still 0xff.
   If not, continue to #3.

3. ata_bus_post_reset() waits readiness of dev0 and/or dev1 depending
   on devmask using ata_sff_wait_ready().

And for post-hardreset readiness,

1. ata_sff_wait_after_reset() waits for 150ms and then for
   ATA_TMOUT_FF_WAIT if status is 0xff and other conditions meet.

2. sata_sff_hardreset waits for device readiness using
   ata_sff_wait_ready().

This patch merges and unifies post-reset readiness waits into
ata_sff_wait_ready() and ata_sff_wait_after_reset().

ATA_TMOUT_FF_WAIT handling is merged into ata_sff_wait_ready().  If TF
status is 0xff, link status is unknown and the port is SATA, it will
continue polling till ATA_TMOUT_FF_WAIT.

ata_sff_wait_after_reset() is updated to perform the following steps.

1. waits for 150ms.

2. waits for dev0 readiness using ata_sff_wait_ready().  Note that
   this is done regardless of devmask, as ata_sff_wait_ready() handles
   0xff status correctly, this preserves the original behavior except
   that it may wait longer after softreset if link is online but
   status is 0xff.  This behavior change is very unlikely to cause any
   actual difference and is intended.  It brings softreset behavior to
   that of hardreset.

3. waits for dev1 readiness just the same way ata_bus_post_reset() did.

Now both soft and hard resets call ata_sff_wait_after_reset() after
reset to wait for readiness after resets.  As
ata_sff_wait_after_reset() contains calls to ->sff_dev_select(),
explicit call near the end of sata_sff_hardreset() is removed.

This change makes reset implementation simpler and more consistent.

While at it, make the magical 150ms wait post-reset wait duration a
constant and ata_sff_wait_ready() and ata_sff_wait_after_reset() take
@link instead of @ap.  This is to make them consistent with other
reset helpers and ease core changes.

pata_scc is updated accordingly.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Separate out generic ATA portion from ata_sff_postreset() into
ata_std_postreset() and implement ata_sff_postreset() using the std
version.

ata_base_port_ops now has ata_std_postreset() for its postreset and
ata_sff_port_ops overrides it to ata_sff_postreset().

This change affects pdc_adma, ahci, sata_fsl and sata_sil24.  pdc_adma
now specifies postreset to ata_sff_postreset() explicitly.  sata_fsl
and sata_sil24 now use ata_std_postreset() which makes no difference
to them.  ahci now calls ata_std_postreset() from its own postreset
method, which causes no behavior difference.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Separate out generic ATA portion from ata_sff_prereset() into
ata_std_prereset() and implement ata_sff_prereset() using the std
version.  Waiting for device readiness is the only SFF specific part.

ata_base_port_ops now has ata_std_prereset() for its prereset and
ata_sff_port_ops overrides it to ata_sff_prereset().  This change can
affect pdc_adma, ahci, sata_fsl and sata_sil24.  pdc_adma implements
its own prereset using ata_sff_prereset() and the rest has hardreset
and thus are unaffected by this change.

This change reflects real world situation.  There is no generic way to
wait for device readiness for non-SFF controllers and some of them
don't have any mechanism for that.  Non-sff drivers which don't have
hardreset should wrap ata_std_prereset() and wait for device readiness
itself but there's no such driver now and isn't likely to be popular
in the future either.
Signed-off-by: NTejun Heo <htejun@gmail.com>

->sff_irq_clear() is called only from SFF interrupt handler, so there
is no reason to initialize it for non-SFF controllers.  Also,
ata_sff_irq_clear() can handle both BMDMA and non-BMDMA SFF
controllers.

This patch kills ata_noop_irq_clear() and removes it from base
port_ops and sets ->sff_irq_clear to ata_sff_irq_clear() in sff
port_ops instead of bmdma port_ops.
Signed-off-by: NTejun Heo <htejun@gmail.com>

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: NTejun Heo <htejun@gmail.com>