scsi: esp_scsi: Declare SCSI host template const

Make it explicit that the SCSI host template is not modified.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230322195515.1267197-35-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: esp_scsi: Stop using the SCSI pointer

Set .cmd_size in the SCSI host template instead of using the SCSI pointer
from struct scsi_cmnd. This patch prepares for removal of the SCSI pointer
from struct scsi_cmnd.

Link: https://lore.kernel.org/r/20220218195117.25689-20-bvanassche@acm.org
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: esp_scsi: Add support for FSC chip

The FSC (NCR53CF9x-2 / SYM53CF9x-2) has a different family code than QLogic
or Emulex parts. This caused it to be detected as a FAS100A.

Unforunately, this meant the configuration of the CONFIG3 register was
incorrect. This causes data transfer issues with FAST-SCSI targets.

The FSC also has the CONFIG4 register. It can be used to enable a feature
called Active Negation which should always be enabled according to the data
manual.

Link: https://lore.kernel.org/r/20191119202021.28720-3-jongk@linux-m68k.org
Reviewed-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Kars de Jong <jongk@linux-m68k.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: esp_scsi: Correct ordering of PCSCSI definition in esp_rev enum

The order of the definitions in the esp_rev enum is important. The values
are used in comparisons for chip features.

Add a comment to the enum explaining this.

Also, the actual values for the enum fields are irrelevant, so remove the
explicit values (suggested by Geert Uytterhoeven). This makes adding a new
field in the middle of the enum easier.

Finally, move the PCSCSI definition to the right place in the enum. In its
previous location, at the end of the enum, the wrong values are written to
the CONFIG3 register when used with FAST-SCSI targets.

Link: https://lore.kernel.org/r/20191119202021.28720-2-jongk@linux-m68k.org
Signed-off-by: Kars de Jong <jongk@linux-m68k.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: esp: use sg helper to iterate over scatterlist

Unlike the legacy I/O path, scsi-mq preallocates a large array to hold
the scatterlist for each request. This static allocation can consume
substantial amounts of memory on modern controllers which support a
large number of concurrently outstanding requests.

To facilitate a switch to a smaller static allocation combined with a
dynamic allocation for requests that need it, we need to make sure all
SCSI drivers handle chained scatterlists correctly.

Convert remaining drivers that directly dereference the scatterlist
array to using the iterator functions.

[mkp: clarified commit message]

Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Guenter Roeck <linux@roeck-us.net>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: esp_scsi: De-duplicate PIO routines

As a temporary measure, the code to implement PIO transfers was
duplicated in zorro_esp and mac_esp. Now that it has stabilized move the
common code into the core driver but don't build it unless needed.

This replaces the inline assembler with more portable writesb() calls.
Optimizing the m68k writesb() implementation is a separate patch.

[mkp: applied by hand]

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>

scsi: esp_scsi: Eliminate ESP_FLAG_DOING_SLOWCMD

The concept of a 'slow command' as it appears in esp_scsi is confusing
because it could refer to an ESP command or a SCSI command. It turns out
that it refers to a particular ESP select command which the driver also
tracks as 'ESP_SELECT_MSGOUT'. For readability, it is better to use the
terminology from the datasheets.

The global ESP_FLAG_DOING_SLOWCMD flag is redundant anyway, as it can be
inferred from esp->select_state. Remove the ESP_FLAG_DOING_SLOWCMD cruft
and just use a boolean local variable.

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

scsi: esp_scsi: Track residual for PIO transfers

If a target disconnects during a PIO data transfer the command may fail
when the target reconnects:

scsi host1: DMA length is zero!
scsi host1: cur adr[04380000] len[00000000]

The scsi bus is then reset. This happens because the residual reached
zero before the transfer was completed.

The usual residual calculation relies on the Transfer Count registers.
That works for DMA transfers but not for PIO transfers. Fix the problem
by storing the PIO transfer residual and using that to correctly
calculate bytes_sent.

Fixes: 6fe07aaffbf0 ("[SCSI] m68k: new mac_esp scsi driver")
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: esp_scsi: remove union in esp_cmd_priv

The dma_addr_t member is unused ever since we switched the SCSI
layer to send down single-segement command using a scatterlist
as well many years ago.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: esp_scsi: move dma mapping into the core code

Except for the mac_esp driver, which uses PIO or pseudo DMA, all drivers
share the same dma mapping calls. Move the dma mapping into the core
code using the scsi_dma_map / scsi_dma_unmap helpers, with a special
identify mapping variant triggered off a new ESP_FLAG_NO_DMA_MAP flag
for mac_esp.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: esp_scsi: remove the dev argument to scsi_esp_register

We can simplify use esp->dev now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: esp_scsi: use strong typing for the dev field

esp->dev is a void pointer that points either to a struct device, or a
struct platform_device. As we can easily get from the device to the
platform_device if needed change it to always point to a struct device
and properly type the pointer to avoid errors.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: esp_scsi: Clean up control flow and dead code

This patch improves readability. There are no functional changes.

Since this touches on a questionable ESP_INTR_DC conditional, add some
commentary to help others who may (as I did) find themselves chasing an
"Invalid Command" error after the device flags this condition.

This cleanup also eliminates a warning from "make W=1":
drivers/scsi/esp_scsi.c: In function 'esp_finish_select':
drivers/scsi/esp_scsi.c:1233:5: warning: variable 'orig_select_state' set but not used [-Wunused-but-set-variable]
u8 orig_select_state;

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

esp_scsi: correctly detect am53c974

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: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

am53c974: BLAST residual handling

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: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

esp_scsi: use FIFO for command submission

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: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

esp_scsi: make number of tags configurable

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: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

esp_scsi: spellcheck 'driver'

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

esp_scsi: Fix tag state corruption when autosensing.

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: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>

sparc: Kill SBUS DVMA layer.

This thing was completely pointless.

Just find the OF device in the parent of drivers that want to program
this device, and map the DMA regs inside such drivers too.

This also moves the dummy claim_dma_lock() and release_dma_lock()
implementation to floppy_32.h, which makes it handle this issue
just like floppy_64.h does.

Signed-off-by: David S. Miller <davem@davemloft.net>

[SCSI] esp: tidy up target reference counting

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: David S. Miller <davem@davemloft.net>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] esp: Fix OOPS in esp_reset_cleanup().

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: David S. Miller <davem@davemloft.net>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] m68k: new mac_esp scsi driver

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: Finn Thain <fthain@telegraphics.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] esp_scsi: Make cur_residue and tot_residue signed.

Many of the overflow checks test whether the value has
gone negative, and we want to retain such checks.

Reported by Julia Lawall.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] ESP: Revert ESP_BUS_TIMEOUT back down to 250

This reverts d73f5222a618a91452d41c29f5996ce3d9c63673

The bug that made us increase ESP_BUS_TIMEOUT to 275 turned out to be
a memset bug on 32-bit sparc.

It is better to put this back at the correct timeout value than to
leave it increased when there is no reason for doing so.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] ESP: Increase ESP_BUS_TIMEOUT to 275.

This matches the original driver's value and seems to be
necessary for some disks on sun4c systems.

Reported by Mark Fortescue <mark@mtfhpc.demon.co.uk>

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] esp: use shost_priv

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

[SCSI] SUNESP: Complete driver rewrite to version 2.0

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: David S. Miller <davem@davemloft.net>