linux/include/sound/sof/channel_map.h
Gustavo A. R. Silva 5224f79096 treewide: Replace zero-length arrays with flexible-array members
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].

This code was transformed with the help of Coccinelle:
(next-20220214$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)

@@
identifier S, member, array;
type T1, T2;
@@

struct S {
  ...
  T1 member;
  T2 array[
- 0
  ];
};

UAPI and wireless changes were intentionally excluded from this patch
and will be sent out separately.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2022-02-17 07:00:39 -06:00

62 lines
2.0 KiB
C

/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
/*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* Copyright(c) 2019 Intel Corporation. All rights reserved.
*/
#ifndef __IPC_CHANNEL_MAP_H__
#define __IPC_CHANNEL_MAP_H__
#include <uapi/sound/sof/header.h>
#include <sound/sof/header.h>
/**
* \brief Channel map, specifies transformation of one-to-many or many-to-one.
*
* In case of one-to-many specifies how the output channels are computed out of
* a single source channel,
* in case of many-to-one specifies how a single target channel is computed
* from a multichannel input stream.
*
* Channel index specifies position of the channel in the stream on the 'one'
* side.
*
* Ext ID is the identifier of external part of the transformation. Depending
* on the context, it may be pipeline ID, dai ID, ...
*
* Channel mask describes which channels are taken into account on the "many"
* side. Bit[i] set to 1 means that i-th channel is used for computation
* (either as source or as a target).
*
* Channel mask is followed by array of coefficients in Q2.30 format,
* one per each channel set in the mask (left to right, LS bit set in the
* mask corresponds to ch_coeffs[0]).
*/
struct sof_ipc_channel_map {
uint32_t ch_index;
uint32_t ext_id;
uint32_t ch_mask;
uint32_t reserved;
int32_t ch_coeffs[];
} __packed;
/**
* \brief Complete map for each channel of a multichannel stream.
*
* num_ch_map Specifies number of items in the ch_map.
* More than one transformation per a single channel is allowed (in case
* multiple external entities are transformed).
* A channel may be skipped in the transformation list, then it is filled
* with 0's by the transformation function.
*/
struct sof_ipc_stream_map {
struct sof_ipc_cmd_hdr hdr;
uint32_t num_ch_map;
uint32_t reserved[3];
struct sof_ipc_channel_map ch_map[];
} __packed;
#endif /* __IPC_CHANNEL_MAP_H__ */