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)
38 lines
1.1 KiB
C
38 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* See Documentation/circular-buffers.txt for more information.
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*/
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#ifndef _LINUX_CIRC_BUF_H
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#define _LINUX_CIRC_BUF_H 1
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struct circ_buf {
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char *buf;
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int head;
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int tail;
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};
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/* Return count in buffer. */
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#define CIRC_CNT(head,tail,size) (((head) - (tail)) & ((size)-1))
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/* Return space available, 0..size-1. We always leave one free char
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as a completely full buffer has head == tail, which is the same as
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empty. */
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#define CIRC_SPACE(head,tail,size) CIRC_CNT((tail),((head)+1),(size))
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/* Return count up to the end of the buffer. Carefully avoid
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accessing head and tail more than once, so they can change
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underneath us without returning inconsistent results. */
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#define CIRC_CNT_TO_END(head,tail,size) \
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({int end = (size) - (tail); \
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int n = ((head) + end) & ((size)-1); \
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n < end ? n : end;})
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/* Return space available up to the end of the buffer. */
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#define CIRC_SPACE_TO_END(head,tail,size) \
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({int end = (size) - 1 - (head); \
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int n = (end + (tail)) & ((size)-1); \
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n <= end ? n : end+1;})
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#endif /* _LINUX_CIRC_BUF_H */
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