scsi: mac_scsi: Mark driver struct with __refdata to prevent section mismatch

As described in the added code comment, a reference to .exit.text is ok for
drivers registered via module_platform_drive

scsi: mac_scsi: Mark driver struct with __refdata to prevent section mismatch

As described in the added code comment, a reference to .exit.text is ok for
drivers registered via module_platform_driver_probe(). Make this explicit
to prevent the following section mismatch warning

WARNING: modpost: drivers/scsi/mac_scsi: section mismatch in reference: mac_scsi_driver+0x8 (section: .data) -> mac_scsi_remove (section: .exit.text)

that triggers on an allmodconfig W=1 build.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/e41d10906948a980e985f6065485445d9bbbd2f7.1711746359.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: mac: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error han

scsi: mac: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

In the error path emit an error message replacing the (less useful)
message by the core. Apart from the improved error message there is no
change in behaviour.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/89ce161dad52d99df07135531512ccecb7f25d14.1701619134.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: NCR5380: Add SCp members to struct NCR5380_cmd

This is necessary for the eventual removal of SCp from struct scsi_cmnd.

Link: https://lore.kernel.org/r/20220218195117.25689-9-bvanassche@acm.o

scsi: NCR5380: Add SCp members to struct NCR5380_cmd

This is necessary for the eventual removal of SCp from struct scsi_cmnd.

Link: https://lore.kernel.org/r/20220218195117.25689-9-bvanassche@acm.org
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Ondrej Zary <linux@zary.sk>
Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: NCR5380: Remove the NCR5380_CMD_SIZE macro

This makes it easier to find users of the NCR5380_cmd data structure with
'grep'.

Link: https://lore.kernel.org/r/20220218195117.25689-8-bvanassche@

scsi: NCR5380: Remove the NCR5380_CMD_SIZE macro

This makes it easier to find users of the NCR5380_cmd data structure with
'grep'.

Link: https://lore.kernel.org/r/20220218195117.25689-8-bvanassche@acm.org
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Ondrej Zary <linux@rainbow-software.org>
Cc: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: NCR5380: Remove context check

NCR5380_poll_politely2() uses in_interrupt() and irqs_disabled() to check
if it is safe to sleep.

Such usage in drivers is phased out and Linus clearly requested

scsi: NCR5380: Remove context check

NCR5380_poll_politely2() uses in_interrupt() and irqs_disabled() to check
if it is safe to sleep.

Such usage in drivers is phased out and Linus clearly requested that code
which changes behaviour depending on context should either be separated, or
the context be explicitly conveyed in an argument passed by the caller.

Below is a context analysis of NCR5380_poll_politely2() uppermost callers:

- NCR5380_maybe_reset_bus(), task, invoked during device probe.
-> NCR5380_poll_politely()
-> do_abort()

- NCR5380_select(), task, but can only sleep in the "release, then
re-acquire" regions of the spinlock held by its caller.
Sleeping invocations (lock released):
-> NCR5380_poll_politely2()

Atomic invocations (lock acquired):
-> NCR5380_reselect()
-> NCR5380_poll_politely()
-> do_abort()
-> NCR5380_transfer_pio()

- NCR5380_intr(), interrupt handler
-> NCR5380_dma_complete()
-> NCR5380_transfer_pio()
-> NCR5380_poll_politely()
-> NCR5380_reselect() (see above)

- NCR5380_information_transfer(), task, but can only sleep in the
"release, then re-acquire" regions of the caller-held spinlock.
Sleeping invocations (lock released):
- NCR5380_transfer_pio() -> NCR5380_poll_politely()
- NCR5380_poll_politely()

Atomic invocations (lock acquired):
- NCR5380_transfer_dma()
-> NCR5380_dma_recv_setup()
=> generic_NCR5380_precv() -> NCR5380_poll_politely()
=> macscsi_pread() -> NCR5380_poll_politely()

-> NCR5380_dma_send_setup()
=> generic_NCR5380_psend -> NCR5380_poll_politely2()
=> macscsi_pwrite() -> NCR5380_poll_politely()

-> NCR5380_poll_politely2()
-> NCR5380_dma_complete()
-> NCR5380_transfer_pio()
-> NCR5380_poll_politely()
- NCR5380_transfer_pio() -> NCR5380_poll_politely

- NCR5380_reselect(), atomic, always called with hostdata spinlock
held.

Since NCR5380_poll_politely2() already takes a "wait" argument in jiffies,
use it to determine if the function can sleep. Modify atomic callers, which
passed an unused wait value in terms of HZ, to pass zero.

Link: https://lore.kernel.org/r/20201206075157.19067-1-a.darwish@linutronix.de
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: <linux-m68k@lists.linux-m68k.org>
Suggested-by: Finn Thain <fthain@telegraphics.com.au>
Co-developed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: atari_scsi: sun3_scsi: Set sg_tablesize to 1 instead of SG_NONE

Since the scsi subsystem adopted the blk-mq API, a host with zero
sg_tablesize crashes with a NULL pointer dereference.

blk_que

scsi: atari_scsi: sun3_scsi: Set sg_tablesize to 1 instead of SG_NONE

Since the scsi subsystem adopted the blk-mq API, a host with zero
sg_tablesize crashes with a NULL pointer dereference.

blk_queue_max_segments: set to minimum 1
scsi 0:0:0:0: Direct-Access QEMU QEMU HARDDISK 2.5+ PQ: 0 ANSI: 5
scsi target0:0:0: Beginning Domain Validation
scsi target0:0:0: Domain Validation skipping write tests
scsi target0:0:0: Ending Domain Validation
blk_queue_max_segments: set to minimum 1
scsi 0:0:1:0: Direct-Access QEMU QEMU HARDDISK 2.5+ PQ: 0 ANSI: 5
scsi target0:0:1: Beginning Domain Validation
scsi target0:0:1: Domain Validation skipping write tests
scsi target0:0:1: Ending Domain Validation
blk_queue_max_segments: set to minimum 1
scsi 0:0:2:0: CD-ROM QEMU QEMU CD-ROM 2.5+ PQ: 0 ANSI: 5
scsi target0:0:2: Beginning Domain Validation
scsi target0:0:2: Domain Validation skipping write tests
scsi target0:0:2: Ending Domain Validation
blk_queue_max_segments: set to minimum 1
blk_queue_max_segments: set to minimum 1
blk_queue_max_segments: set to minimum 1
blk_queue_max_segments: set to minimum 1
sr 0:0:2:0: Power-on or device reset occurred
sd 0:0:0:0: Power-on or device reset occurred
sd 0:0:1:0: Power-on or device reset occurred
sd 0:0:0:0: [sda] 10485762 512-byte logical blocks: (5.37 GB/5.00 GiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
Unable to handle kernel NULL pointer dereference at virtual address (ptrval)
Oops: 00000000
Modules linked in:
PC: [<001cd874>] blk_mq_free_request+0x66/0xe2
SR: 2004 SP: (ptrval) a2: 00874520
d0: 00000000 d1: 00000000 d2: 009ba800 d3: 00000000
d4: 00000000 d5: 08000002 a0: 0087be68 a1: 009a81e0
Process kworker/u2:2 (pid: 15, task=(ptrval))
Frame format=7 eff addr=0000007a ssw=0505 faddr=0000007a
wb 1 stat/addr/data: 0000 00000000 00000000
wb 2 stat/addr/data: 0000 00000000 00000000
wb 3 stat/addr/data: 0000 0000007a 00000000
push data: 00000000 00000000 00000000 00000000
Stack from 0087bd98:
00000002 00000000 0087be72 009a7820 0087bdb4 001c4f6c 009a7820 0087bdd4
0024d200 009a7820 0024d0dc 0087be72 009baa00 0087be68 009a5000 0087be7c
00265d10 009a5000 0087be72 00000003 00000000 00000000 00000000 0087be68
00000bb8 00000005 00000000 00000000 00000000 00000000 00265c56 00000000
009ba60c 0036ddf4 00000002 ffffffff 009baa00 009ba600 009a50d6 0087be74
00227ba0 009baa08 00000001 009baa08 009ba60c 0036ddf4 00000000 00000000
Call Trace: [<001c4f6c>] blk_put_request+0xe/0x14
[<0024d200>] __scsi_execute+0x124/0x174
[<0024d0dc>] __scsi_execute+0x0/0x174
[<00265d10>] sd_revalidate_disk+0xba/0x1f02
[<00265c56>] sd_revalidate_disk+0x0/0x1f02
[<0036ddf4>] strlen+0x0/0x22
[<00227ba0>] device_add+0x3da/0x604
[<0036ddf4>] strlen+0x0/0x22
[<00267e64>] sd_probe+0x30c/0x4b4
[<0002da44>] process_one_work+0x0/0x402
[<0022b978>] really_probe+0x226/0x354
[<0022bc34>] driver_probe_device+0xa4/0xf0
[<0002da44>] process_one_work+0x0/0x402
[<0022bcd0>] __driver_attach_async_helper+0x50/0x70
[<00035dae>] async_run_entry_fn+0x36/0x130
[<0002db88>] process_one_work+0x144/0x402
[<0002e1aa>] worker_thread+0x0/0x570
[<0002e29a>] worker_thread+0xf0/0x570
[<0002e1aa>] worker_thread+0x0/0x570
[<003768d8>] schedule+0x0/0xb8
[<0003f58c>] __init_waitqueue_head+0x0/0x12
[<00033e92>] kthread+0xc2/0xf6
[<000331e8>] kthread_parkme+0x0/0x4e
[<003768d8>] schedule+0x0/0xb8
[<00033dd0>] kthread+0x0/0xf6
[<00002c10>] ret_from_kernel_thread+0xc/0x14
Code: 0280 0006 0800 56c0 4400 0280 0000 00ff <52b4> 0c3a 082b 0006 0013 6706 2042 53a8 00c4 4ab9 0047 3374 6640 202d 000c 670c
Disabling lock debugging due to kernel taint

Avoid this by setting sg_tablesize = 1.

Link: https://lore.kernel.org/r/4567bcae94523b47d6f3b77450ba305823bca479.1572656814.git.fthain@telegraphics.com.au
Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Michael Schmitz <schmitzmic@gmail.com>
References: commit 68ab2d76e4be ("scsi: cxlflash: Set sg_tablesize to 1 instead of SG_NONE")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: mac_scsi: Treat Last Byte Sent time-out as failure

A system bus error during a PDMA send operation can result in bytes being
lost. Theoretically that could cause the target to remain in DATA O

scsi: mac_scsi: Treat Last Byte Sent time-out as failure

A system bus error during a PDMA send operation can result in bytes being
lost. Theoretically that could cause the target to remain in DATA OUT phase
and the initiator (expecting a phase change) would time-out waiting for the
Last Byte Sent flag. Should that happen, fail the transfer so the core
driver will stop using PDMA with this target.

Cc: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: mac_scsi: Enable PDMA on Mac IIfx

Add support for Apple's custom "SCSI DMA" chip. This patch doesn't make use
of its DMA capability. Just the PDMA capability is sufficient to improve
sequentia

scsi: mac_scsi: Enable PDMA on Mac IIfx

Add support for Apple's custom "SCSI DMA" chip. This patch doesn't make use
of its DMA capability. Just the PDMA capability is sufficient to improve
sequential read throughput by a factor of 5.

Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Joshua Thompson <funaho@jurai.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: mac_scsi: Fix pseudo DMA implementation, take 2

A system bus error during a PDMA transfer can mess up the calculation of
the transfer residual (the PDMA handshaking hardware lacks a byte
count

scsi: mac_scsi: Fix pseudo DMA implementation, take 2

A system bus error during a PDMA transfer can mess up the calculation of
the transfer residual (the PDMA handshaking hardware lacks a byte
counter). This results in data corruption.

The algorithm in this patch anticipates a bus error by starting each
transfer with a MOVE.B instruction. If a bus error is caught the transfer
will be retried. If a bus error is caught later in the transfer (for a
MOVE.W instruction) the transfer gets failed and subsequent requests for
that target will use PIO instead of PDMA.

This avoids the "!REQ and !ACK" error so the severity level of that message
is reduced to KERN_DEBUG.

Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org # v4.14+
Fixes: 3a0f64bfa907 ("mac_scsi: Fix pseudo DMA implementation")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reported-by: Chris Jones <chris@martin-jones.com>
Tested-by: Stan Johnson <userm57@yahoo.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: mac_scsi: Increase PIO/PDMA transfer length threshold

Some targets introduce delays when handshaking the response to certain
commands. For example, a disk may send a 96-byte response to an INQ

scsi: mac_scsi: Increase PIO/PDMA transfer length threshold

Some targets introduce delays when handshaking the response to certain
commands. For example, a disk may send a 96-byte response to an INQUIRY
command (or a 24-byte response to a MODE SENSE command) too slowly.

Apparently the first 12 or 14 bytes are handshaked okay but then the system
bus error timeout is reached while transferring the next word.

Since the scsi bus phase hasn't changed, the driver then sets the target
borken flag to prevent further PDMA transfers. The driver also logs the
warning, "switching to slow handshake".

Raise the PDMA threshold to 512 bytes so that PIO transfers will be used
for these commands. This default is sufficiently low that PDMA will still
be used for READ and WRITE commands.

The existing threshold (16 bytes) was chosen more or less at random.
However, best performance requires the threshold to be as low as possible.
Those systems that don't need the PIO workaround at all may benefit from
mac_scsi.setup_use_pdma=1

Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: stable@vger.kernel.org # v4.14+
Fixes: 3a0f64bfa907 ("mac_scsi: Fix pseudo DMA implementation")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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treewide: Add SPDX license identifier for more missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have MODULE_LICENCE("GPL*") inside which

treewide: Add SPDX license identifier for more missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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scsi: remove the use_clustering flag

The same effects can be achieved by setting the dma_boundary to
PAGE_SIZE - 1 and the max_segment_size to PAGE_SIZE, so shift those
settings into the drivers. N

scsi: remove the use_clustering flag

The same effects can be achieved by setting the dma_boundary to
PAGE_SIZE - 1 and the max_segment_size to PAGE_SIZE, so shift those
settings into the drivers. Note that in many cases the setting might
be bogus, but this keeps the status quo.

[mkp: fix myrs and myrb]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: NCR5380: Move bus reset to host reset

The bus reset handler really is a host reset, so move it to
eh_bus_reset_handler.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Finn Thain <ft

scsi: NCR5380: Move bus reset to host reset

The bus reset handler really is a host reset, so move it to
eh_bus_reset_handler.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: ncr5380: Resolve various static checker warnings

Avoid various warnings from "make C=1" by annotating a couple of
unlock-then-lock sequences, replacing a zero with NULL and correcting
some typ

scsi: ncr5380: Resolve various static checker warnings

Avoid various warnings from "make C=1" by annotating a couple of
unlock-then-lock sequences, replacing a zero with NULL and correcting
some type casts.

Also avoid a warning from "make W=1" by adding braces.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: ncr5380: Use correct types for DMA routines

Apply prototypes to get consistent function signatures for the DMA
functions implemented in the board-specific drivers. To avoid using
macros to alt

scsi: ncr5380: Use correct types for DMA routines

Apply prototypes to get consistent function signatures for the DMA
functions implemented in the board-specific drivers. To avoid using
macros to alter actual parameters, some of those functions are reworked
slightly.

This is a step toward the goal of passing the board-specific routines
to the core driver using an ops struct (as in a platform driver or
library module).

This also helps fix some inconsistent types: where the core driver uses
ints (cmd->SCp.this_residual and hostdata->dma_len) for keeping track of
transfers, certain board-specific routines used unsigned long.

While we are fixing these function signatures, pass the hostdata pointer
to DMA routines instead of a Scsi_Host pointer, for shorter and faster
code.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: ncr5380: Pass hostdata pointer to register polling routines

Pass a NCR5380_hostdata struct pointer to the board-specific routines
instead of a Scsi_Host struct pointer. This reduces pointer ch

scsi: ncr5380: Pass hostdata pointer to register polling routines

Pass a NCR5380_hostdata struct pointer to the board-specific routines
instead of a Scsi_Host struct pointer. This reduces pointer chasing in
the PIO and PDMA fast paths. The old way was a mistake because it is
slow and the board-specific code is not concerned with the mid-layer.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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scsi: ncr5380: Use correct types for device register accessors

For timeout values adopt unsigned long, which is the type of jiffies etc.

For chip register values and bit masks pass u8, which is the

scsi: ncr5380: Use correct types for device register accessors

For timeout values adopt unsigned long, which is the type of jiffies etc.

For chip register values and bit masks pass u8, which is the return type
of readb, inb etc.

For device register offsets adopt unsigned int, as it is suitable for
adding to base addresses.

Pass the NCR5380_hostdata pointer to the board-specific routines instead
of the Scsi_Host pointer. The board-specific code is concerned with
hardware and not with SCSI protocol or the mid-layer.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

scsi: ncr5380: Store IO ports and addresses in host private data

The various 5380 drivers inconsistently store register pointers
either in the Scsi_Host struct "legacy crap" area or in special,
boar

scsi: ncr5380: Store IO ports and addresses in host private data

The various 5380 drivers inconsistently store register pointers
either in the Scsi_Host struct "legacy crap" area or in special,
board-specific members of the NCR5380_hostdata struct. Uniform
use of the latter struct makes for simpler and faster code (see
the following patches) and helps to reduce use of the
NCR5380_implementation_fields macro.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

show more ...

mac_scsi: Fix pseudo DMA implementation

Fix various issues: Comments about bus errors are incorrect. The
PDMA asm must return the size of the memory access that faulted so the
transfer count can be

mac_scsi: Fix pseudo DMA implementation

Fix various issues: Comments about bus errors are incorrect. The
PDMA asm must return the size of the memory access that faulted so the
transfer count can be adjusted accordingly. A phase change may cause a
bus error but should not be treated as failure. A bus error does not
always imply a phase change and generally the transfer may continue.
Scatter/gather doesn't seem to work with PDMA due to overruns. This is
a pity because peak throughput seems to double with SG_ALL.
Tested on a Mac LC III and a PowerBook 520.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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ncr5380: Remove disused atari_NCR5380.c core driver

Now that atari_scsi and sun3_scsi have been converted to use the NCR5380.c
core driver, remove atari_NCR5380.c. Also remove the last vestiges of i

ncr5380: Remove disused atari_NCR5380.c core driver

Now that atari_scsi and sun3_scsi have been converted to use the NCR5380.c
core driver, remove atari_NCR5380.c. Also remove the last vestiges of its
Tagged Command Queueing implementation from the wrapper drivers.

The TCQ support in atari_NCR5380.c is abandoned by this patch. It is not
merged into the remaining core driver because,

1) atari_scsi defines SUPPORT_TAGS but leaves FLAG_TAGGED_QUEUING disabled
by default, which indicates that it is mostly undesirable.

2) I'm told that it doesn't work correctly when enabled.

3) The algorithm does not make use of block layer tags which it will have
to do because scmd->tag is deprecated.

4) sun3_scsi doesn't define SUPPORT_TAGS at all, yet the the SUPPORT_TAGS
macro interacts with the CONFIG_SUN3 macro in 'interesting' ways.

5) Compile-time configuration with macros like SUPPORT_TAGS caused the
configuration space to explode, leading to untestable and unmaintainable
code that is too hard to reason about.

The merge_contiguous_buffers() code is also abandoned. This was unused
by sun3_scsi. Only atari_scsi used it and then only on TT, because only TT
supports scatter/gather. I suspect that the TT would work fine with
ENABLE_CLUSTERING instead. If someone can benchmark the difference then
perhaps the merge_contiguous_buffers() code can be be justified. Until
then we are better off without the extra complexity.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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ncr5380: Merge DMA implementation from atari_NCR5380 core driver

Adopt the DMA implementation from atari_NCR5380.c. This means that
atari_scsi and sun3_scsi can make use of the NCR5380.c core driver

ncr5380: Merge DMA implementation from atari_NCR5380 core driver

Adopt the DMA implementation from atari_NCR5380.c. This means that
atari_scsi and sun3_scsi can make use of the NCR5380.c core driver
and the atari_NCR5380.c driver fork can be made redundant.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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ncr5380: Use DMA hooks for PDMA

Those wrapper drivers which use DMA define the REAL_DMA macro and
those which use pseudo DMA define PSEUDO_DMA. These macros need to be
removed for a number of reason

ncr5380: Use DMA hooks for PDMA

Those wrapper drivers which use DMA define the REAL_DMA macro and
those which use pseudo DMA define PSEUDO_DMA. These macros need to be
removed for a number of reasons, not least of which is to have drivers
share more code.

Redefine the PDMA send and receive hooks as DMA setup hooks, so that the
DMA code can be shared by all 5380 wrapper drivers. This will help to
reunify the forked core driver.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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ncr5380: Remove PSEUDO_DMA macro

For those wrapper drivers which only implement Programmed IO, have
NCR5380_dma_xfer_len() evaluate to zero. That allows PDMA to be easily
disabled at run-time and so

ncr5380: Remove PSEUDO_DMA macro

For those wrapper drivers which only implement Programmed IO, have
NCR5380_dma_xfer_len() evaluate to zero. That allows PDMA to be easily
disabled at run-time and so the PSEUDO_DMA macro is no longer needed.

Also remove the spin counters used for debugging pseudo DMA drivers.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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ncr5380: Remove FLAG_NO_PSEUDO_DMA where possible

Drivers that define PSEUDO_DMA also define NCR5380_dma_xfer_len.
The core driver must call NCR5380_dma_xfer_len which means
FLAG_NO_PSEUDO_DMA can b

ncr5380: Remove FLAG_NO_PSEUDO_DMA where possible

Drivers that define PSEUDO_DMA also define NCR5380_dma_xfer_len.
The core driver must call NCR5380_dma_xfer_len which means
FLAG_NO_PSEUDO_DMA can be eradicated from the core driver.

dmx3191d doesn't define PSEUDO_DMA and has no use for FLAG_NO_PSEUDO_DMA,
so remove it there also.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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ncr5380: Fix soft lockups

Because of the rudimentary design of the chip, it is necessary to poll the
SCSI bus signals during PIO and this tends to hog the CPU. The driver will
accept new commands wh

ncr5380: Fix soft lockups

Because of the rudimentary design of the chip, it is necessary to poll the
SCSI bus signals during PIO and this tends to hog the CPU. The driver will
accept new commands while others execute, and this causes a soft lockup
because the workqueue item will not terminate until the issue queue is
emptied.

When exercising dmx3191d using sequential IO from dd, the driver is sent
512 KiB WRITE commands and 128 KiB READs. For a PIO transfer, the rate is
is only about 300 KiB/s, so these are long-running commands. And although
PDMA may run at several MiB/s, interrupts are disabled for the duration
of the transfer.

Fix the unresponsiveness and soft lockup issues by calling cond_resched()
after each command is completed and by limiting max_sectors for drivers
that don't implement real DMA.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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