Updated diff which doesn't move the comment as per Jeff's request and
corrects the docs as per report on l/k
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Most of these contributed by that mysterious figger known as A.C.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

> Looks like you should use ata_busy_wait() here, rather than reproducing
> the same code again.

It waits in 10uS chunks while 1uS chunks were used in the workaround.
Could indeed do that once I know the fix is right. While I'm at it the
ata_busy_wait kerneldoc is borked so here's a fix
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Some uli controllers have stuck SIMPLEX bit which can't be cleared
with ata_pci_clear_simplex(), but the controller is capable of doing
DMAs on both channels simultaneously.  Implement ATA_FLAG_IGN_SIMPLEX
which makes libata ignore the simplex bit and use it in sata_uli.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

When set_mode() changed ->set_mode didn't adapt. This makes the needed
changes and removes the relevant FIXME case.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Initialize qc->pad_len for each new command. This ensures
that pad_len is not set to a stale value for zero data
length commands.
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Fixup the inialization of qc->n_elem. It currently gets
initialized to 1 for commands that do not transfer any data.
Fix this by initializing n_elem to 0 and only setting to 1
in ata_scsi_qc_new when there is data to transfer. This fixes
some problems seen with SATA devices attached to ipr adapters.
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

libata didn't used to init qc->dma_dir to any specific value on qc
initialization and command translation path didn't set qc->dma_dir if
the command doesn't need data transfer.  This made non-data commands
to have random qc->dma_dir.

This usually doesn't cause problem because LLDs usually check
qc->protocol first and look at qc->dma_dir iff the command needs data
transfer but this doesn't hold for all LLDs.

It might be worthwhile to rename qc->dma_dir to qc->data_dir as we use
the field to tag data direction for both PIO and DMA protocols.

This problem has been spotted by James Bottomley.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

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>

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>

HSM_ST_UNKNOWN is not used anywhere.  Its value is zero and supposed
to serve sanity check purpose but HSM_ST_IDLE is used for that
purpose.  This unused state causes confusion.  After a port is
initialized but before the first command is executed, the idle hsm
state is UNKNOWN.  However, once a command has completed, the idle hsm
state is IDLE.  This defeats sanity check in ata_pio_task() for the
first command.

This patch removes HSM_ST_UNKNOWN and consequently make HSM_ST_IDLE
the default state.
Signed-off-by: NTejun Heo <htejun@gmail.com>

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>

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>

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>

ata_irq_on() isn't used outside of libata core layer.  The function is
TF/SFF interface specific but currently used by core path with some
hack too.  Move it from include/linux/libata.h to
drivers/ata/libata-sff.c.
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>

Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.

For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.

To make this work, an extra flag is introduced into the management side of the
work_struct.  This governs auto-release of the structure upon execution.

Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function.  This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated..  This is a
problem if the auxiliary data is taken away (as done by the last patch).

However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems.  But then the work function must itself release the
work_struct by calling work_release().

In most cases, automatic release is fine, so this is the default.  Special
initiators exist for the non-auto-release case (ending in _NAR).
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

Separate delayable work items from non-delayable work items be splitting them
into a separate structure (delayed_work), which incorporates a work_struct and
the timer_list removed from work_struct.

The work_struct struct is huge, and this limits it's usefulness.  On a 64-bit
architecture it's nearly 100 bytes in size.  This reduces that by half for the
non-delayable type of event.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

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>

Typo fix in commment.
Signed-off-by: NTejun Heo <htejun@gmail.com>
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)

Turn off NCQ if queue depth is adjusted to 1.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Cosmetic changes to ATA_DFLAG_* constants for soon-to-follow NCQ-off
patch.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Signed-off-by: NJeff Garzik <jeff@garzik.org>

They all contain the same thing.  Instead, have a single generic one in
include/asm-generic, and permit an arch to override as needed.
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 vast majority of drivers and changes are from Alan Cox.  Albert Lee
contributed and maintains pata_pdc2027x.  Adrian Bunk, Andrew Morton,
and Tejun Heo contributed various minor fixes and updates.
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>

Also, moved ATA_MAX_SECTORS and ATA_MAX_SECTORS_LBA48 from
linux/libata.h to linux/ata.h, now that they truly reflect the standard
(well... mostly; note TODO comment).

This changes the performance profile (and potential bug profile)
for a bunch of drivers, so be wary.

Kill unused probe_ent/ap->hard_port_no and probe_ent->legacy_mode.
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>

The following patch enhances libata to allow SAS device drivers
to utilize libata to talk to SATA devices. It introduces some
new APIs which allow libata to be used without allocating a
virtual scsi host.

New APIs:

ata_sas_port_alloc - Allocate an ata_port
ata_sas_port_init - Initialize an ata_port (probe device, etc)
ata_sas_port_destroy - Free an ata_port allocated by ata_sas_port_alloc
ata_sas_slave_configure - configure scsi device
ata_sas_queuecmd - queue a scsi command, similar to ata_scsi_queuecomand

These new APIs can be used either directly by a SAS LLDD or could be used
by the SAS transport class.

Possible usage for a SAS LLDD would be:

scsi_scan_host
	target_alloc
		ata_sas_port_alloc
	slave_alloc
		ata_sas_port_init
	slave_configure
		ata_sas_slave_configure

Commands received by the LLDD for SATA devices would call ata_sas_queuecmd.

Device teardown would occur with:

slave_destroy
	port_disable
target_destroy
	ata_sas_port_destroy
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Add ata_host_set_init in preparation for SAS attached SATA.
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>