threeeye
bc1d038eac
Squashed backup commit (no shallow-clone history issues) of xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2 branch, upstream commit 9eece662e) plus all fixes applied to get everpal_defconfig building clean against a modern (GCC 15.2.0) toolchain -- see the previous commit message on the lineage-23.2 branch (also in this repo history is not available here since this is a squashed snapshot; full incremental history lives in the local DL380 checkout and the upstream GitHub remote). Upstream: https://github.com/xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2)
96 lines
3.7 KiB
C
96 lines
3.7 KiB
C
/*
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* Copyright (C) 2016 MediaTek Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See http://www.gnu.org/licenses/gpl-2.0.html for more details.
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*/
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#ifndef _RING_H_
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#define _RING_H_
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struct ring {
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/* addr where ring buffer starts */
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void *base;
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/* addr storing the next writable pos, guaranteed to be >= read except when write overflow, but it's ok. */
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unsigned int write;
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/* addr storing the next readable pos, except when read == write as buffer empty */
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unsigned int read;
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/* must be power of 2 */
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unsigned int max_size;
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};
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struct ring_segment {
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/* addr points into ring buffer for read/write */
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void *ring_pt;
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/* size to read/write */
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unsigned int sz;
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/* pos in external data buffer to read/write */
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unsigned int data_pos;
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/* the size to be read/write after this segment completed */
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unsigned int remain;
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};
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void ring_init(void *base, unsigned int max_size, unsigned int read,
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unsigned int write, struct ring *ring);
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unsigned int ring_read_prepare(unsigned int sz, struct ring_segment *seg, struct ring *ring);
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#define ring_read_all_prepare(seg, ring) ring_read_prepare((ring)->max_size, seg, ring)
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unsigned int ring_write_prepare(unsigned int sz, struct ring_segment *seg, struct ring *ring);
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unsigned int ring_overwrite_prepare(unsigned int sz,
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struct ring_segment *seg, struct ring *ring);
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/* making sure max_size is power of 2 */
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#define RING_VALIDATE_SIZE(max_size) WARN_ON(!max_size || (max_size & (max_size - 1)))
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#define RING_EMPTY(ring) ((ring)->read == (ring)->write)
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/* equation works even when write overflow */
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#define RING_SIZE(ring) ((ring)->write - (ring)->read)
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#define RING_FULL(ring) (RING_SIZE(ring) == (ring)->max_size)
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#define RING_WRITE_REMAIN_SIZE(ring) ((ring)->max_size - RING_SIZE(ring))
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#define RING_READ_FOR_EACH(_sz, _seg, _ring) \
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for (ring_read_prepare(_sz, &(_seg), _ring), \
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_ring_segment_prepare((_ring)->read, &(_seg), (_ring)); \
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(_seg).sz > 0; \
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_ring_read_commit(&(_seg), (_ring)), _ring_segment_prepare((_ring)->read, \
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&(_seg), (_ring)))
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#define RING_READ_ALL_FOR_EACH(seg, ring) RING_READ_FOR_EACH((ring)->max_size, seg, ring)
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#define RING_READ_FOR_EACH_ITEM(_sz, _seg, _ring) \
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for (ring_read_prepare(_sz, &(_seg), _ring), \
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_ring_segment_prepare_item((_ring)->read, &(_seg), (_ring)); \
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(_seg).sz > 0; \
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_ring_read_commit(&(_seg), (_ring)), _ring_segment_prepare_item((_ring)->read, \
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&(_seg), (_ring)))
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#define RING_WRITE_FOR_EACH(_sz, _seg, _ring) \
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for (ring_write_prepare(_sz, &(_seg), _ring),\
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_ring_segment_prepare((_ring)->write, &(_seg), (_ring)); \
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(_seg).sz > 0; \
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_ring_write_commit(&(_seg), (_ring)), _ring_segment_prepare((_ring)->write, \
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&(_seg), (_ring)))
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#define RING_OVERWRITE_FOR_EACH(_sz, _seg, _ring) \
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for (ring_overwrite_prepare(_sz, &(_seg), _ring), \
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_ring_segment_prepare((_ring)->write, &(_seg), (_ring)); \
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(_seg).sz > 0; \
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_ring_write_commit(&(_seg), (_ring)), _ring_segment_prepare((_ring)->write, \
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&(_seg), (_ring)))
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void ring_dump(const char *title, struct ring *ring);
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void ring_dump_segment(const char *title, struct ring_segment *seg);
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/* ring Buffer Internal API */
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void _ring_segment_prepare(unsigned int from, struct ring_segment *seg, struct ring *ring);
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void _ring_segment_prepare_item(unsigned int from, struct ring_segment *seg, struct ring *ring);
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void _ring_read_commit(struct ring_segment *seg, struct ring *ring);
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void _ring_write_commit(struct ring_segment *seg, struct ring *ring);
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#endif
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