media: venus: hfi_cmds: Replace one-element array with flex-array member and use __counted_by

Array `data` in `struct hfi_sfr` is being used as a fake flexible array
at run-time:

drivers/media/platform/qcom/venus/hfi_venus.c:
1033 p = memchr(sfr->data, '\0', sfr->buf_size);
1034 /*
1035 * SFR isn't guaranteed to be NULL terminated since SYS_ERROR indicates
1036 * that Venus is in the process of crashing.
1037 */
1038 if (!p)
1039 sfr->data[sfr->buf_size - 1] = '\0';
1040
1041 dev_err_ratelimited(dev, "SFR message from FW: %s\n", sfr->data);

Fake flexible arrays are deprecated, and should be replaced by
flexible-array members. So, replace one-element array with a
flexible-array member in `struct hfi_sfr`.

While there, also annotate array `data` with __counted_by() to prepare
for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

This results in no differences in binary output.

This issue was found with the help of Coccinelle, and audited and fixed
manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Stanimir Varbanov <stanimir.k.varbanov@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

media: venus: hfi_cmds: Replace one-element array with flexible-array member

One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element arrays with flexible-array
members in struct hfi_session_set_buffers_pkt, and refactor the rest of
the code, accordingly.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].

This results in no differences in binary output.

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/292
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Stanimir Varbanov <stanimir.k.varbanov@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: venus: hfi_cmds: Replace fake flex-array with flexible-array member

One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element arrays with flexible-array
members in struct hfi_sys_set_resource_pkt, and refactor the rest of
the code, accordingly.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].

The only binary differences seen before/after changes are the
following:

17ba: mov %rbx,%rdi
17bd: call 17c2 <pkt_sys_set_resource+0x42>
17be: R_X86_64_PLT32 __tsan_write4-0x4
- 17c2: movl $0x14,(%rbx)
+ 17c2: movl $0x10,(%rbx)
17c8: lea 0x4(%rbx),%rdi
17cc: call 17d1 <pkt_sys_set_resource+0x51>
17cd: R_X86_64_PLT32 __tsan_write4-0x4

which is expected once this accounts for the following line of code
at drivers/media/platform/qcom/venus/hfi_cmds.c:73

73 pkt->hdr.size = sizeof(*pkt);

and as *pkt is of type struct hfi_sys_set_resource_pkt, sizeof(*pkt) is
reduced by 4 bytes, due to the flex-array transformation.

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/293
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Stanimir Varbanov <stanimir.k.varbanov@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: venus: set ubwc configuration on specific video hardware

UBWC configuration parameters would vary across video hardware
generations. At the same time, driver is expected to configure these
parameters, without relying on video firmware to use the default
configurations.
Setting the configuration parameters for sc7280.

Signed-off-by: Vikash Garodia <quic_vgarodia@quicinc.com>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: venus: hfi_cmds.h: Replace one-element array with flexible-array member

There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

Use flexible-array member in struct hfi_sys_set_property_pkt instead of
one-element array.

Also, this helps with the ongoing efforts to enable -Warray-bounds and
fix the following warnings:

drivers/media/platform/qcom/venus/hfi_cmds.c: In function ‘pkt_sys_coverage_config’:
drivers/media/platform/qcom/venus/hfi_cmds.c:57:11: warning: array subscript 1 is above array bounds of ‘u32[1]’ {aka ‘unsigned int[1]’} [-Warray-bounds]
57 | pkt->data[1] = mode;
| ~~~~~~~~~^~~

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/602416da.iZqae7Dbk7nyl6OY%25lkp@intel.com/

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: venus: hfi_cmds.h: Replace zero-length array with flexible-array member

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>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 284

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 and
only 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

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 294 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.825281744@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[media] media: venus: hfi: add Host Firmware Interface (HFI)

This is the implementation of HFI. It is charged with the
responsibility to comunicate with the firmware through an
interface commands and messages.

- hfi.c has interface functions used by the core, decoder
and encoder parts to comunicate with the firmware. For example
there are functions for session and core initialisation.

- hfi_cmds has packetization operations which preparing
packets to be send from host to firmware.

- hfi_msgs takes care of messages sent from firmware to the
host.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>