MESSAGE REJECT does not imply DISCONNECT: the target is about to enter
MESSAGE IN or MESSAGE OUT phase.

This bug fix comes from atari_NCR5380.c. Unfortunately it never made it
into the original NCR5380.c core driver.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some old drivers partially implemented support for linked commands using
a "proposed" next_link pointer in struct scsi_cmnd that never actually
existed. Remove this code.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Remove the DEF_SCSI_QCMD macro (already removed from atari_NCR5380.c). The
lock provided by DEF_SCSI_QCMD is only needed for queue data structures.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The host spin lock needs to be acquired by NCR5380_abort() before it calls
NCR5380_select(). This patch doesn't actually fix the EH issues in this
driver but it does avoid this:

BUG: spinlock already unlocked on CPU#0, kworker/u4:1/14
 lock: 0xc0c0f834, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1
 CPU: 0 PID: 14 Comm: kworker/u4:1 Not tainted 3.15.5 #5
 Workqueue: scsi_tmf_4 scmd_eh_abort_handler
 Call Trace:
 [ef885d70] [c0008acc] show_stack+0x70/0x1bc (unreliable)
 [ef885db0] [c0492a00] dump_stack+0x84/0x684
 [ef885dc0] [c006f314] spin_dump+0xd0/0xe8
 [ef885dd0] [c006f460] do_raw_spin_unlock+0xd4/0xd8
 [ef885df0] [c0491c8c] _raw_spin_unlock_irq+0x10/0x3c
 [ef885e00] [f381fe3c] NCR5380_select+0x3e4/0x6e8 [dmx3191d]
 [ef885e40] [f382026c] NCR5380_abort+0x12c/0x190 [dmx3191d]
 [ef885e60] [c02fec9c] scmd_eh_abort_handler+0x100/0x460
 [ef885e80] [c0046470] process_one_work+0x16c/0x420
 [ef885ea0] [c0046870] worker_thread+0x14c/0x430
 [ef885ed0] [c004e4f4] kthread+0xd8/0xec
 [ef885f40] [c00124d4] ret_from_kernel_thread+0x5c/0x64
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

According to the SCSI-2 draft revision 10L, atari_NCR5380.c is correct
when it says that the phase lines are valid up until ACK is negated
following the transmission of the last byte in MESSAGE IN phase. This is
true for all information transfer phases, from target to initiator.

Sample the phase bits in STATUS_REG so that NCR5380_transfer_pio() can
return the correct result. The return value is presently unused (perhaps
because of bugs like this) but this change at least fixes the caller's
phase variable, which is passed by reference.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The atari_NCR5380.c and NCR5380.c core drivers differ in their handling of
target disconnection. This is partly because atari_NCR5380.c had all of
the polling and sleeping removed to become entirely interrupt-driven, and
it is partly because of damage done to NCR5380.c after atari_NCR5380.c was
forked. See commit 37cd23b44929 ("Linux 2.1.105") in history/history.git.

The polling changes that were made in v2.1.105 are questionable at best:
if REQ is not already asserted when NCR5380_transfer_pio() is invoked, and
if the expected phase is DATA IN or DATA OUT, the function will schedule
main() to execute after USLEEP_SLEEP jiffies and then return. The problems
here are the expected REQ timing and the sleep interval*. Avoid this issue
by using NCR5380_poll_politely() instead of scheduling main().

The atari_NCR5380.c core driver requires the use of the chip interrupt and
always permits target disconnection. It sets the cmd->device->disconnect
flag when a device disconnects, but never tests this flag.

The NCR5380.c core driver permits disconnection only when
instance->irq != NO_IRQ. It sets the cmd->device->disconnect flag when
a device disconnects and it tests this flag in a couple of places:

1. During NCR5380_information_transfer(), following COMMAND OUT phase,
   if !cmd->device->disconnect, the initiator will take a guess as to
   whether or not the target will then choose to go to MESSAGE IN phase
   and disconnect. If the driver guesses "yes", it will schedule main()
   to execute after USLEEP_SLEEP jiffies and then return there.

   Unfortunately the driver may guess "yes" even after it has denied
   the target the disconnection privilege. When the target does not
   disconnect, the sleep can be beneficial, assuming the sleep interval
   is appropriate (mostly it is not*).

   And even if the driver guesses "yes" correctly, and the target would
   then disconnect, the driver still has to go through the MESSAGE IN
   phase in order to get to BUS FREE phase. The main loop can do nothing
   useful until BUS FREE, and sleeping just delays the phase transition.

2. If !cmd->device->disconnect and REQ is not already asserted when
   NCR5380_information_transfer() is invoked, the function polls for REQ
   for USLEEP_POLL jiffies. If REQ is not asserted, it then schedules
   main() to execute after USLEEP_SLEEP jiffies and returns.

   The idea is apparently to yeild the CPU while waiting for REQ.
   This is conditional upon !cmd->device->disconnect, but there seems
   to be no rhyme or reason for that. For example, the flag may be
   unset because disconnection privilege was denied because the driver
   has no IRQ. Or the flag may be unset because the device has never
   needed to disconnect before. Or if the flag is set, disconnection
   may have no relevance to the present bus phase.

Another deficiency of the existing algorithm is as follows. When the
driver has no IRQ, it prevents disconnection, and generally polls and
sleeps more than it would normally. Now, if the driver is going to poll
anyway, why not allow the target to disconnect? That way the driver can do
something useful with the bus instead of polling unproductively!

Avoid this pointless latency, complexity and guesswork by using
NCR5380_poll_politely() instead of scheduling main().

* For g_NCR5380, the time intervals for USLEEP_SLEEP and USLEEP_POLL are
  200 ms and 10 ms, respectively. They are 20 ms and 200 ms respectively
  for the other NCR5380 drivers. There doesn't seem to be any reason for
  this discrepancy. The timing seems to have no relation to the type of
  adapter. Bizarrely, the timing in g_NCR5380 seems to relate only to one
  particular type of target device. This patch attempts to solve the
  problem for all NCR5380 drivers and all target devices.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Follow the example of the atari_NCR5380.c core driver and adopt the
NCR5380_dma_xfer_len() hook. Implement NCR5380_dma_xfer_len() for dtc.c
and g_NCR5380.c to take care of the limitations of these cards. Keep the
default for drivers using PSEUDO_DMA.

Eliminate the unused macro LIMIT_TRANSFERSIZE.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

If NCR5380_select() returns -1, it means arbitration was lost or selection
failed and should be retried. If the main loop simply terminates when there
are still commands on the issue queue, they will remain queued until they
expire.

Fix this by clearing the 'done' flag after selection failure or lost
arbitration.

The "else break" clause in NCR5380_main() that gets removed here appears
to be a vestige of a long-gone loop that iterated over host instances.
See commit 491447e1fcff ("[PATCH] next NCR5380 updates") in
history/history.git.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Linux v2.1.105 changed the algorithm for polling for the BSY signal
in NCR5380_select() and NCR5380_main().

Presently, this code has a bug. Back then, NCR5380_set_timer(hostdata, 1)
meant reschedule main() after sleeping for 10 ms. Repeated 25 times this
provided the recommended 250 ms selection time-out delay. This got broken
when HZ became configurable.

We could fix this but there's no need to reschedule the main loop. This
BSY polling presently happens when the NCR5380_main() work queue item
calls NCR5380_select(), which in turn schedules NCR5380_main(), which
calls NCR5380_select() again, and so on.

This algorithm is a deviation from the simpler one in atari_NCR5380.c.
The extra complexity and state is pointless. There's no reason to
stop selection half-way and return to to the main loop when the main
loop can do nothing useful until selection completes.

So just poll for BSY. We can sleep while polling now that we have a
suitable workqueue.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When in process context, sleep during polling if doing so won't add
significant latency. In interrupt context or if the lock is held, poll
briefly then give up. Keep both core drivers in sync.

Calibrate busy-wait iterations to allow for variation in chip register
access times between different 5380 hardware implementations.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Allocate a work queue that will permit busy waiting and sleeping. This
means NCR5380_init() can potentially fail, so add this error path.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Commit 8b801ead ("[ARM] rpc: update Acorn SCSI drivers to modern ecard
interfaces") neglected to remove a request_region() call in cumana_1.c.

Commit eda32612f7b2 ("[PATCH] give all LLDD driver a ->release method") in
history/history.git added some pointless release_region() calls in dtc.c,
pas16.c and t128.c.

Fix these issues.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Linux 2.1.105 introduced the USLEEP_WAITLONG delay, apparently "needed for
Mustek scanners". It is intended to stall the issue queue for 5 seconds.
There are a number of problems with this.

1. Only g_NCR5380 enables the delay, which implies that the other five
   drivers using the NCR5380.c core driver remain incompatible with
   Mustek scanners.

2. The delay is not implemented by atari_NCR5380.c, which is problematic
   for re-unifying the two core driver forks.

3. The delay is implemented using NCR5380_set_timer() which makes it
   unreliable. A new command queued by the mid-layer cancels the delay.

4. The delay is applied indiscriminately in several situations in which
   NCR5380_select() returns -1. These are-- reselection by the target,
   failure of the target to assert BSY, and failure of the target to
   assert REQ. It's clear from the comments that USLEEP_WAITLONG is not
   relevant to the reselection case. And reportedly, these scanners do
   not disconnect.

5. atari_NCR5380.c was forked before Linux 2.1.105, so it was spared some
   of the damage done to NCR5380.c. In this case, the atari_NCR5380.c core
   driver was more standard-compliant and may not have needed any
   workaround like the USLEEP_WAITLONG kludge. The compliance issue was
   addressed in the previous patch.

If these scanners still don't work, we need a better solution. Retrying
selection until EH aborts a command offers equivalent robustness. Bugs in
the existing driver prevent EH working correctly but this is addressed in
a subsequent patch. Remove USLEEP_WAITLONG.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

NCR5380.c is not compliant with the SCSI-2 standard (at least, not with
the draft revision 10L that I have to refer to). The selection algorithm
in atari_NCR5380.c is correct, so use that.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

If a target disappears from the SCSI bus, NCR5380_select() may
subsequently fail with a time-out. In this situation, scsi_done is
called and NCR5380_select() returns 0. Both hostdata->connected and
hostdata->selecting are NULL and the main loop should proceed with
the next command in the issue queue. Clarify this logic.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Remove the restart_select and targets_present variables introduced in
Linux v1.1.38. The former was used only for a questionable debug printk
and the latter "so we can call a select failure a retryable condition".
Well, retrying select failure in general is a different problem to a
target that doesn't assert BSY. We need to handle these two cases
differently; the latter case can be left to the SCSI ML.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The "failed" label in NCR5380_select() is not helpful. Some failures
return 0, others -1. Use return instead of goto to improve clarity and
brevity, like atari_NCR5380.c does. Fix the relevant comments.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Remove the duplicate write to the Select Enable Register that appeared
in v1.1.38.

Also remove the redundant write to Initiator Command Register prior to
calling do_abort().
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The aborted flag was introduced in v1.1.38 but never used. Remove it.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Make use of do_reset() in the bus reset handler in atari_NCR5380.c. The
version in NCR5380.c already does so. Keep them in sync.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The atari_NCR5380.c core driver now takes care of bus reset upon driver
initialization if required (same as NCR5380.c). Move the Toshiba CD-ROM
support into the core driver, enabled with a host flag, so that all
NCR5380 drivers can make use of it.

Drop the RESET_BOOT macros and the ATARI_SCSI_RESET_BOOT and
ATARI_SCSI_TOSHIBA_DELAY Kconfig symbols, which are now redundant.

Remove the atari_scsi_reset_boot(), mac_scsi_reset_boot() and
sun3_scsi_reset_boot() routines. None of this duplicated code is needed
now that all drivers can use NCR5380_maybe_reset_bus().

This brings atari_scsi, mac_scsi and sun3_scsi into line with all of the
other NCR5380 drivers.

The bus reset may raise an interrupt. That would be new behaviour for
atari_scsi only when CONFIG_ATARI_SCSI_RESET_BOOT=n. The ST DMA interrupt
is not assigned to atari_scsi at this stage, so
CONFIG_ATARI_SCSI_RESET_BOOT=y may well be problematic already.
Regardless, do_reset() now raises and clears the interrupt within
local_irq_save/restore which should avoid problems.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Merge the bus reset code from NCR5380.c into atari_NCR5380.c. This allows
for removal of a lot of duplicated code conditional on the RESET_BOOT
macro (in the next patch).

The atari_NCR5380.c fork lacks the do_reset() and NCR5380_poll_politely()
routines from NCR5380.c, so introduce them. They are indispensible. Keep
the two implementations in sync.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Move board-specific code like this,
	NCR5380_write(C400_CONTROL_STATUS_REG, CSR_BASE);
from the core driver to the board driver. Eliminate the NCR53C400 macro
from the core driver. Removal of all macros like this one will be
necessary in order to have one core driver that can support all kinds of
boards.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch splits the NCR5380_init() function into two parts, similar
to the scheme used with atari_NCR5380.c. This avoids two problems.

Firstly, NCR5380_init() may perform a bus reset, which would cause the
chip to assert IRQ. The chip is unable to mask its bus reset interrupt.
Drivers can't call request_irq() before calling NCR5380_init(), because
initialization must happen before the interrupt handler executes. If
driver initialization causes an interrupt it may be problematic on some
platforms. To avoid that, first move the bus reset code into
NCR5380_maybe_reset_bus().

Secondly, NCR5380_init() contains some board-specific interrupt setup code
for the NCR53C400 that does not belong in the core driver. In moving this
code, better not re-order interrupt initialization and bus reset. Again,
the solution is to move the bus reset code into NCR5380_maybe_reset_bus().
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This macro makes the code cryptic. Remove it.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The NCR5380_local_declare and NCR5380_setup macros exist to define and
initialize a particular local variable, to provide the address of the
chip registers needed for the driver's implementation of its
NCR5380_read/write register access macros.

In cumana_1 and macscsi, these macros generate pointless code like this,
	struct Scsi_Host *_instance;
	_instance = instance;

In pas16, the use of NCR5380_read/write in pas16_hw_detect() requires that
the io_port local variable has been defined and initialized, but the
NCR5380_local_declare and NCR5380_setup macros can't be used for that
purpose because the Scsi_Host struct has not yet been instantiated.

Moreover, these macros were removed from atari_NCR5380.c long ago and
now they constitute yet another discrepancy between the two core driver
forks.

Remove these "optimizations".
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

ASM macro is never defined. rtrc in pas16.c is not used.
NCR5380_map_config, do_NCR5380_intr, do_t128_intr and do_pas16_intr
are unused. NCR_NOT_SET harms readability. Remove them.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Replace {P,T,DTC}DEBUG_INIT with NDEBUG_INIT. Remove dead debugging
code, including code that's conditional upon *DEBUG_TRANSFER.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The NVRAM location of this byte is 16, as documented in
http://toshyp.atari.org/en/004009.html

This was confirmed by Michael Schmitz, by setting the SCSI host ID
under EmuTOS and then checking the value in /proc/driver/nvram and
/dev/nvram under Linux.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This drop enables a future card with a device id of 0x0600 to be
recognized by the cxlflash driver.

As per the design, the Accelerator Function Unit (AFU) for this new IBM
CXL Flash Adapter retains the same host interface as the previous
generation. For the early prototypes of the new card, the driver with
this change behaves exactly as the driver prior to this behaved with the
earlier generation card. Therefore, no card specific programming has
been added. These card specific changes can be staged in later if
needed.
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

If an async error interrupt is generated, and the error requires the FC
link to be reset, it cannot be performed in the interrupt context. So a
work element is scheduled to complete the link reset in a process
context. If either an EEH event or an escalation occurs in between when
the interrupt is generated and the scheduled work is started, the MMIO
space may no longer be available. This will cause an oops in the worker
thread.

[  606.806583] NIP kthread_data+0x28/0x40
[  606.806633] LR wq_worker_sleeping+0x30/0x100
[  606.806694] Call Trace:
[  606.806721] 0x50 (unreliable)
[  606.806796] wq_worker_sleeping+0x30/0x100
[  606.806884] __schedule+0x69c/0x8a0
[  606.806959] schedule+0x44/0xc0
[  606.807034] do_exit+0x770/0xb90
[  606.807109] die+0x300/0x460
[  606.807185] bad_page_fault+0xd8/0x150
[  606.807259] handle_page_fault+0x2c/0x30
[  606.807338] wait_port_offline.constprop.12+0x60/0x130 [cxlflash]

To prevent the problem space area from being unmapped, when there is
pending work, a mapcount (using the kref mechanism) is held.  The
mapcount is released only when the work is completed.  The last
reference release is tied to the unmapping service.
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

After a few iterations of resetting the card, either during EEH
recovery, or a host_reset the following is seen in the logs.  cxlflash
0008:00: cxlflash_queuecommand: could not get a free command

At every reset of the card, the commands that are outstanding are being
leaked.  No effort is being made to reap these commands.  A few more
resets later, the above error message floods the logs and the card is
rendered totally unusable as no free commands are available.

Iterated through the 'cmd' queue and printed out the 'free' counter and
found that on each reset certain commands were in-use and stayed in-use
through subsequent resets.

To resolve this issue, when the card is reset, reap all the commands
that are active/outstanding.
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Having a date for the driver requires it to be updated quite
often. Removing the date which is not necessary. Also made
use of the existing symbol to print the driver name.
Signed-off-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Applications which use virtual LUN's that are backed by a physical LUN
over both adapter ports may experience an I/O failure in the event of a
link loss (e.g. cable pull).

Virtual LUNs may be accessed through one or both ports of the adapter.
This access is encoded in the translation entries that comprise the
virtual LUN and used by the AFU for load-balancing I/O and handling
failover scenarios. In a link loss scenario, even though the AFU is able
to maintain connectivity to the LUN, it is up to the application to
retry the failed I/O. When applications are unaware of the virtual LUN's
underlying topology, they are unable to make a sound decision of when to
retry an I/O and therefore are forced to make their reaction to a failed
I/O absolute. The result is either a failure to retry I/O or increased
latency for scenarios where a retry is pointless.

To remedy this scenario, provide feedback back to the application on
virtual LUN creation as to which ports the LUN may be accessed. LUN's
spanning both ports are candidates for a retry in a presence of an I/O
failure.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: NManoj Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The original fix to escalate a 'login timed out' error to a LINK_RESET
was only made for one of the two ports on the card. This fix resolves
the same issue for the second port (port 1).
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

On the interrupt path, we repeatedly establish the pointer to the
storvsc_device. While the compiler does inline get_in_stor_device() (and
other static functions) in the call chain in the interrupt path, the
compiler is repeatedly inlining the call to get_in_stor_device() each
time it is invoked.  The return value of get_in_stor_device() can be
cached in the interrupt path since there is higher level serialization
in place to ensure correct handling when the module unload races with
the processing of an incoming message from the host.  Optimize this code
path by caching the pointer to storvsc_device and passing it as an
argument.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The function storvsc_channel_init() repeatedly interacts with the host
to extract various channel properties. Refactor this code to eliminate
code repetition.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For FC devices managed by this driver, atttach the appropriate transport
template. This will allow us to create the appropriate sysfs files for
these devices. With this we can publish the wwn for both the port and the node.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NLong Li <longli@microsoft.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The hv_fc_wwn_packet is exchanged over vmbus. Make the definition in
Linux match the Windows definition.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NLong Li <longli@microsoft.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>