CONFIG2_FENAB ('feature enable') changed definition between chip
revisions, from 'Latch SCSI Phase' to 'Latch SCSI Phase, display
chip ID upon reset, and enable 24 bit addresses'.
So only enable it for am53c974 where we know what it's doing.
Acked-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

On PCscsi, the FENAB configuration also enables 24-bit DMA
transfer lengths (and provides the chip id in TCHI after reset).
We want to be able to enable this parameter from the DMA driver.

Check if the caller of scsi_esp_register provided a value for esp->config2.
If this is the case, assume this is not an ESP100, skip the detection
phase and leave esp->config2 untouched.  It will be used in esp_reset_esp.
Reviewed-by: NHannes Reinecke <hare@suse.de>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The am53c974 returns the same ID as the FAS236, but implements
things slightly differently. So detect the am53c974 by checking
for ESP_CONFIG4 register.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The am53c974 has an design issue where a single byte might be
left in the SCSI FIFO after a DMA transfer.
As the handling code is currently untested add a WARN_ON()
statement here.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Using DMA for command submission has the drawback that it might
generate additional DMA completion interrupts after the command
has been submitted to the device.
Additionally the am53c974 has a design flaw causing it
to generate spurious interrupts even though DMA completion
interrupts are not enabled.
This can be avoided by using the FIFO for command submission.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

A read to ESP_INTRPT will clear ESP_STATUS and ESP_SSTEP. So read
all status registers in one go to avoid losing information.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Add new debug definitions for event and command logging.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Use dev_printk functions for correct device annotations.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Add a field 'num_tags' to the esp structure to allow drivers
to overwrite the number of avialable tags if required.
Default is ESP_DEFAULT_TAGS.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth.  For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway.  The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>

Allow a driver to ask for block layer tags by setting .use_blk_tags in the
host template, in which case it will always see a valid value in
request->tag, similar to the behavior when using blk-mq.  This means even
SCSI "untagged" commands will now have a tag, which is especially useful
when using a host-wide tag map.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>

Unless we want to build a SPI tag message we should just check SCMD_TAGGED
instead of reverse engineering a tag type through the use of
scsi_populate_tag_msg.

Also rename the function to spi_populate_tag_msg, make it behave like the
other spi message helpers, and move it to the spi transport class.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>

Meelis Roos reports a crash in esp_free_lun_tag() in the presense
of a disk which has died.

The issue is that when we issue an autosense command, we do so by
hijacking the original command that caused the check-condition.

When we do so we clear out the ent->tag[] array when we issue it via
find_and_prep_issuable_command().  This is so that the autosense
command is forced to be issued non-tagged.

That is problematic, because it is the value of ent->tag[] which
determines whether we issued the original scsi command as tagged
vs. non-tagged (see esp_alloc_lun_tag()).

And that, in turn, is what trips up the sanity checks in
esp_free_lun_tag().  That function needs the original ->tag[] values
in order to free up the tag slot properly.

Fix this by remembering the original command's tag values, and
having esp_alloc_lun_tag() and esp_free_lun_tag() use them.
Reported-by: NMeelis Roos <mroos@linux.ee>
Tested-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Emit the function name not the address when possible.

builtin_return_address() gives an address.  When building
a kernel with CONFIG_KALLSYMS, emit the actual function
name not the address.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

- kenrel -> kernel
- whetehr -> whether
- ttt -> tt
- sss -> ss
Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NKirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation.  No locking or other behavior should change
with this patch.  All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
	struct Scsi_Host *
and remove one parameter from queuecommand,
	void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change.  Most drivers
needed only two one-line modifications for their host lock push-down.
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>
Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The mac_esp PIO algorithm no longer works in 2.6.31 and crashes my Centris
660av. So here's a better one.

Also, force async with esp_set_offset() rather than esp_slave_configure().

One of the SCSI drives I tested still doesn't like the PIO mode and fails
with "esp: esp0: Reconnect IRQ2 timeout" (the same drive works fine in
PDMA mode).

This failure happens when esp_reconnect_with_tag() tries to read in two
tag bytes but the chip only provides one (0x20). I don't know what causes
this. I decided not to waste any more time trying to fix it because the
best solution is to rip out the PIO mode altogether and use the DMA
engine.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Use the macro DIV_ROUND_UP and eliminate the variable rounded_up, as
suggested by Matthew Wilcox.
Signed-off-by: NJulia Lawall <julia@diku.dk>
Cc: David Miller <davem@davemloft.net>
Reviewed-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The features enable bit has to be set in the config2 register
before we can be absolutely sure we will probe a correct
part unique ID and family code from the transfer-count-high
register.

Also, reload the CFACT, STP, SOFF, and TIMEO near the end of
esp_reset_esp().

From a patch by Maciej W. Rozycki.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The esp driver currently does hand rolled reference counting of its
target.  It's much easier to do what it needs to do if it's plugged into
the mid-layer callbacks (target_alloc and target_destroy) which were
designed for this case, so do it this way and get rid of the internal
target reference count.
Acked-by: NDavid S. Miller <davem@davemloft.net>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

OOPS reported by Friedrich Oslage <bluebird@porno-bullen.de>

The problem here is that tp->starget is set every time a lun
is allocated for a particular target so we can catch the
sdev_target parent value.

The reset handler uses the NULL'ness of this value to determine
which targets are active.

But esp_slave_destroy() does not NULL out this value when appropriate.

So for every target that doesn't respond, the SCSI bus scan causes
a stale pointer to be left here, with ensuing crashes like you're
seeing.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Replace the mac_esp driver with a new one based on the esp_scsi core.

For esp_scsi: add support for sync transfers for the PIO mode, add a new
esp_driver_ops method to get the maximum dma transfer size (like the old
NCR53C9x driver), and some cleanups.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The esp_reset_cleanup() function is called with the host lock held and
invokes starget_for_each_device() which wants to take it too.  Here is a
fix along the lines of shost_for_each_device()/__shost_for_each_device()
adding a __starget_for_each_device() counterpart which assumes the lock
has already been taken.

Eventually, I think the driver should get modified so that more work is
done as a softirq rather than in the interrupt context, but for now it
fixes a bug that causes the spinlock debugger to fire.

While at it, it fixes a small number of cosmetic problems with
starget_for_each_device() too.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since scsi_esp_{,un}register() are EXPORT_SYMBOL'ed, these functions
(and the functions they use) can't be __dev{init,exit}.

Based on a bug report by Rob Landley.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Because the ->unique_id is set too late, the ESP scsi host
instance numbers in the kernel log during probing are
wrong.

Bug reported by Meelis Roos.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

- convert to use the new accessors for the sg lists and the
parameters.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

esp_reset_cleanup() does everything necessary except clear
the flag, so we never exit resetting state.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NDavid Miller <davem@davemloft.net>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NMartin Habets <errandir_news@mph.eclipse.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

irqreturn.h for irqreturn_t and dma_addr_t being u128 warnings ;-)
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Major features:

1) Tagged queuing support.
2) Will properly negotiate for synchronous transfers even on
   devices that reject the wide negotiation message, such as
   CDROMs
3) Significantly lower kernel stack usage in interrupt
   handler path by elimination of function vector arrays,
   replaced by a top-level switch statement state machine.
4) Uses generic scsi infrastructure as much as possible to
   avoid code duplication.
5) Automatic request of sense data in response to CHECK_CONDITION
6) Portable to other platforms using ESP such as DEC and Sun3
   systems.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>