libata switched to IRQ-driven IDENTIFY when IRQ-driven PIO was
introduced.  This has caused a lot of problems including device
misdetection and phantom device.

ATA_FLAG_DETECT_POLLING was added recently to selectively use polling
IDENTIFY on problemetic drivers but many controllers and devices are
affected by this problem and trying to adding ATA_FLAG_DETECT_POLLING
for each such case is diffcult and not very rewarding.

This patch makes libata always use polling IDENTIFY.  This is
consistent with libata's original behavior and drivers/ide's behavior.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make ata_sg_clean() global and don't allow NCQ for internal commands.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Separate out rw ATA taskfile building from ata_scsi_rw_xlat() into
ata_build_rw_tf().  This will be used to improve media error handling.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Sg'ify ata_exec_internal() and call it ata_exec_internal_sg().
Wrapper function around ata_exec_internal_sg() is implemented to
provide ata_exec_internal() interface.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Now that BMDMA status is recorded in irq handler.  ata_bmdma_freeze()
is free to manipulate host status.  Under certain circumstances, some
controllers (ICH7 in enhanced mode w/ IRQ shared) raise IRQ when CTL
register is written to and ATA_NIEN doesn't mask it.

This patch makes ata_bmdma_freeze() clear all pending IRQs after
freezing a port.  This change makes explicit clearing in
ata_device_add() unnecessary and thus kills it.  The removed code was
SFF-specific and was in the wrong place.

Note that ->freeze() handler is always called under ap->lock held and
irq disabled.  Even if CTL manipulation causes stuck IRQ, it's cleared
immediately.  This should be safe (enough) even in SMP environment.
More correct solution is to mask the IRQ from IRQ controller but that
would be an overkill.
Signed-off-by: NTejun Heo <htejun@gmail.com>

For certain errors, interrupt handler alter BMDMA host status before
entering EH (clears active and intr).  Thus altered BMDMA host status
value is recorded by BMDMA EH and reported to user.  Move BMDMA host
status recording from EH to interrupt handler.
Signed-off-by: NTejun Heo <htejun@gmail.com>

This patch implements ATA_FLAG_SETXFER_POLLING and use in pata_via.
If this flag is set, transfer mode setting performed by polling not by
interrupt.  This should help those controllers which raise interrupt
before the command is actually complete on SETXFER.

Rationale for this approach.

* uses existing facility and relatively simple
* no busy sleep in the interrupt handler
* updating drivers is easy

While at it, kill now unused flag ATA_FLAG_SRST in pata_via.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Implement ata_tf_read_block().
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

libata didn't initialize result_tf.flags which indicates transfer type
(RW/FUA) and address type (CHS/LBA/LBA48).  ata_gen_fixed_sense()
assumed result_tf.flags equals command tf.flags and failed to report
the first failed block to SCSI layer because zero tf flags indicates
CHS and bad block reporting for CHS is not implemented.

Implement fill_result_tf() which sets result_tf.flags to command
tf.flags and use it to fill result_tf.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

There's no need to memset &qc->sgent manually, sg_init_one() clears
sgent inside it.  Also, kill not-so-necessary sg local variable.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

On some controllers (ICHs in piix mode), there is *NO* reliable way to
determine device presence other than issuing IDENTIFY and see how the
transaction proceeds by watching the TF status register.

libata acted this way before irq-pio and phantom devices caused very
little problem but now that IDENTIFY is performed using IRQ drive PIO,
such phantom devices now result in multiple 30sec timeouts during
boot.

This patch implements ATA_FLAG_DETECT_POLLING.  If a LLD sets this
flag, libata core issues the initial IDENTIFY in polling mode and if
the initial data transfer fails w/ HSM violation, the port is
considered to be empty thus replicating the old libata and IDE
behavior.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make ata_dev_read_id() take @flags instead of @post_reset.  Currently
there is only one flag defined - ATA_READID_POSTRESET, which is
equivalent to @post_reset.  This is preparation for polling presence
detection.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Many drives support LBA48 even when its capacity is smaller than
1<<28, as LBA48 is required for many functionalities.  FLUSH_EXT is
mandatory for drives w/ LBA48 support.

Interestingly, at least one of such drives (ST960812A) has problems
dealing with FLUSH_EXT.  It eventually completes the command but takes
around 7 seconds to finish in many cases thus drastically slowing down
IO transactions.  This seems to be a firmware bug which sneaked into
production probably because no other ATA driver including linux IDE
issues FLUSH_EXT to drives which report support for LBA48 & FLUSH_EXT
but is smaller than 1<<28 blocks.

This patch adds ATA_DFLAG_FLUSH_EXT which is set iff the drive
supports LBA48 & FLUSH_EXT and is larger than LBA28 limit.  Both cache
flush paths are updated to issue FLUSH_EXT only when the flag is set.
Note that the changed behavior is more inline with the rest of libata.
libata prefers shorter commands whenever possible.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Danny Kukawka <dkukawka@novell.com>
Cc: Stefan Seyfried <seife@novell.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Move dev->max_sectors configuration from ata_scsi_dev_config() to
ata_dev_configure().

* more consistent.
* allows LLDs to peek at the default dev->max_sectors value.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

libata EH used to perform ata_set_mode() iff the EH session performed
reset as indicated by ATA_EHI_DID_RESET.  This is incorrect because
->dev_config() called by revalidation is allowed to modify transfer
mode which ata_set_mode() should take care of.  This patch implements
the following two flags.

* ATA_EHI_SETMODE: set during EH to schedule ata_set_mode().  Both new
  device attachment and revalidation set this flag.

* ATA_EHI_POST_SETMODE: set while the device is revalidated after
  ata_set_mode().  Post-setmode revalidation is different from initial
  configuaration and EH revalidation in that ->dev_config() is not
  allowed tune transfer mode.  LLD can use this flag to determine
  whether it's allowed to tune transfer mode.  Note that POST_SETMODE
  ->dev_config() is guaranteed to be preceded by non-POST_SETMODE
  ->dev_config().
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ehi flag ATA_EHI_PRINTINFO.  This flag is set when device
configuration needs to print out device info.  This used to be handled
by @print_info argument to ata_dev_configure() but LLDs also need to
know about it in ->dev_config() callback.

This patch replaces @print_info w/ ATA_EHI_PRINTINFO and make sata_sil
print workaround messages only on the initial configuration.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Separate out sata_port_hardreset() from sata_std_hardreset().  This
will be used by LLD hardreset implementation and later by PMP.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

libata waits for !BSY even when the status register reports 0xff.
This causes long boot delays when D8 isn't pulled down properly.  This
patch does the followings.

* don't wait if status register is 0xff in all wait functions

* make ata_busy_sleep() return 0 on success and -errno on failure.
  -ENODEV is returned on 0xff status and -EBUSY on other failures.

* make ata_bus_softreset() succeed on 0xff status.  0xff status is not
  reset failure.  It indicates no device.  This removes unnecessary
  retries on such ports.  Note that the code change assumes unoccupied
  port reporting 0xff status does not produce valid device signature.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Joe Jin <lkmaillist@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

[deweerdt@free.fr: build fix]
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NFrederik Deweerdt <deweerdt@free.fr>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

When building a monolithic kernel, the load order of drivers does not
work for SAS libata users, resulting in a kernel oops.

Convert libata to use subsys_initcall instead of module_init, which
ensures that libata gets loaded before any LLDD.

This is the same thing that scsi core does to solve the problem.  The
load order problem was observed on ipr SAS adapters and should exist for
other SAS users as well.
Signed-off-by: NBrian King <brking@us.ibm.com>
Acked-by: NJeff Garzik <jgarzik@pobox.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

ata_dev_revalidate() isn't used outside of libata core.  Unexport it.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

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

Update copyright year, fix minor stuff 'make xmldocs' complains about.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

We have the info stored in an ata_busy_sleep() variable, so might as
well print it, and provide some additional diagnostic info.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Don't write the same code twice, in two different functions, when they
both call the same initialization function, with the same private_data
pointer info.

Also, note a bug found with a FIXME.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ata_device_add fails, calls ata_host_remove with pointers to unitialized
memory.
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

We don't currently support pure polled operation so when we meet a BIOS
which forgot to assign an IRQ to a PCI device it all goes a little pear
shaped. Trap this case properly.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Our ATA probe code checks that a device is not reporting a diagnostic
failure during start up. Unfortunately at least one device seems to like
doing this - the Gigabyte iRAM.

This is only done for the master right now (which is fine for the iRAM
as it is SATA), as with PATA some combinations of ATAPI device seem to
fool the check into seeing a drive that isn't there if it is applied to
the slave.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Non-uniform ports handling got broken while updating libata to handle
those in the same host.  Only separate irq for the non-uniform
secondary port was implemented while all other fields (host flags,
transfer mode...) of the secondary port simply shared those of the
first.

For ata_piix combined mode, which ATM is the only user of non-uniform
ports, this causes the secondary port assume the wrong type.  This can
cause PATA port to use SATA ops, which results in bogus check on PCS
and detection failure.

This patch adds ata_probe_ent->pinfo2 which points to optional
port_info for the secondary port.  For the time being, this seems to
be the simplest solution.  This workaround will be removed together
with ata_probe_ent itself after init model is updated to allow more
flexibility.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Nelson A. de Oliveira <naoliv@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

The biggest change is that ata_host_set is renamed to ata_host.

* ata_host_set			=> ata_host
* ata_probe_ent->host_flags	=> ata_probe_ent->port_flags
* ata_probe_ent->host_set_flags	=> ata_probe_ent->_host_flags
* ata_host_stats		=> ata_port_stats
* ata_port->host		=> ata_port->scsi_host
* ata_port->host_set		=> ata_port->host
* ata_port_info->host_flags	=> ata_port_info->flags
* ata_(.*)host_set(.*)\(\)	=> ata_\1host\2()

The leading underscore in ata_probe_ent->_host_flags is to avoid
reusing ->host_flags for different purpose.  Currently, the only user
of the field is libata-bmdma.c and probe_ent itself is scheduled to be
removed.

ata_port->host is reused for different purpose but this field is used
inside libata core proper and of different type.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

The CFA world has some additional rules and drive modes we need to support for
newer expansion cards and on embedded boxes
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Kill unused probe_ent/ap->hard_port_no and probe_ent->legacy_mode.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Use dummy port for stolen legacy ports.  This makes ap->port_no always
equal ap->hard_port_no.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Implement dummy port which can be requested by setting appropriate bit
in probe_ent->dummy_port_mask.  The dummy port is used as placeholder
for stolen legacy port.  This allows libata to guarantee that
index_of(ap) == ap->port_no == actual_device_port_no, and thus to
remove error-prone ap->hard_port_no.

As it's used only when one port of a legacy controller is reserved by
some other entity (e.g. IDE), the focus is on keeping the added *code*
complexity at minimum, so dummy port allocates all libata core
resources and acts as a normal port.  It just has all dummy port_ops.

This patch only implements dummy port.  The following patch will make
libata use it for stolen legacy ports.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Kill host_set->next
Fix simplex support
Allow per platform setting of IDE legacy bases

Some of this can be tidied further later on, in particular all the
legacy port gunge belongs as a PCI quirk/PCI header decode to understand
the special legacy IDE rules in the PCI spec.

Longer term Jeff also wants to move the request_irq/free_irq out of core
which will make this even cleaner.

tj: folded in three followup patches - ata_piix-fix, broken-arch-fix
and fix-new-legacy-handling, and separated per-dev xfermask into
separate patch preceding this one.  Folded in fixes are...

* ata_piix-fix: fix build failure due to host_set->next removal
* broken-arch-fix: add missing include/asm-*/libata-portmap.h
* fix-new-legacy-handling:
	* In ata_pci_init_legacy_port(), probe_num was incorrectly
          incremented during initialization of the secondary port and
          probe_ent->n_ports was incorrectly fixed to 1.

	* Both legacy ports ended up having the same hard_port_no.

	* When printing port information, both legacy ports printed
	  the first irq.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NTejun Heo <htejun@gmail.com>

Implement per-dev xfermask.  libata used to determine xfermask
per-port - the fastest mode of the slowest device on the port.  This
patch enables per-dev xfermask.

Original patch is from Alan Cox <alan@redhat.com>.  The following
changes are made by me.

* simplex warning message is added
* remove disabled device handling code which is never invoked
  (originally for choosing port-wide lowest PIO mode)

Cc: Alan Cox <alan@redhat.com>
Signed-off-by: NTejun Heo <htejun@gmail.com>

Eliminate redundant loop variable 'count'
Signed-off-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NTejun Heo <htejun@gmail.com>