Commit 7f832645d0e5 ("dmaengine: ioatdma: remove ioatdma v2 registration")
missed to remove dca2_tag_map_valid() during its removal. Hence, since
then, dca2_tag_map_valid() is unused and make CC=clang W=1 warns:

  drivers/dma/ioat/dca.c:44:19:
    warning: unused function 'dca2_tag_map_valid' [-Wunused-function]

So, remove this unused function and get rid of a -Wused-function warning.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lore.kernel.org/r/20201113081248.26416-1-lukas.bulwahn@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200214171302.GA20586@embeddedor
Signed-off-by: Vinod Koul <vkoul@kernel.org>

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct ioat_dca_priv {
	...
        struct ioat_dca_slot     req_slots[0];
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

So, replace the following form:

sizeof(*ioatdca) + (sizeof(struct ioat_dca_slot) * slots)

with:

struct_size(ioatdca, req_slots, slots)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20190828184015.GA4273@embeddedor
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details the full gnu general public license is included in
  this distribution in the file called copying

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope [that] it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details the full gnu general public license is included in
  this distribution in the file called copying

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 57 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.515993066@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The WARN_TAINT_ONCE() prints out a loud stack trace on broken BIOSes.
The systems that have this problem are several years out of support and
no longer have BIOS updates available.  The stack trace isn't necessary
and a pr_warn_once() will do.

Change WARN_TAINT_ONCE() to pr_warn_once() and taint.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Duyck, Alexander H <alexander.h.duyck@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The dca_ops structure is never modified, so declare it as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Moving the relevant functions to their respective .c files and removal of
dma_v3.c file. Also removed various ioat3 references when appropriate.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Clean out dma_v2 and remove ioat2 calls since we are moving everything
to just ioat.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Removal of support for ioatdma v2 device support.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Cleaning up of ioat1 specific code as it is no longer supported

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>