1 /* Copyright (c) 2015, The Linux Foundation. All rights reserved. 2 * 3 * Redistribution and use in source and binary forms, with or without 4 * modification, are permitted provided that the following conditions are 5 * met: 6 * * Redistributions of source code must retain the above copyright 7 * notice, this list of conditions and the following disclaimer. 8 * * Redistributions in binary form must reproduce the above 9 * copyright notice, this list of conditions and the following 10 * disclaimer in the documentation and/or other materials provided 11 * with the distribution. 12 * * Neither the name of The Linux Foundation nor the names of its 13 * contributors may be used to endorse or promote products derived 14 * from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 23 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 25 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN 26 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #ifndef __RING_BUFFER_H 30 #define __RING_BUFFER_H 31 32 /* Ring buffer status codes */ 33 enum rb_status { 34 RB_SUCCESS = 0, 35 RB_FAILURE = 1, 36 }; 37 38 struct rb_stats { 39 u32 total_bytes_written; 40 u32 total_bytes_read; 41 u32 cur_valid_bytes; 42 unsigned int max_num_bufs; 43 size_t each_buf_size; 44 }; 45 46 typedef void (*threshold_call_back) (void *cb_ctx); 47 48 /* intiitalizes the ring buffer and returns the context to it */ 49 void * ring_buffer_init(size_t size_of_buf, int num_bufs); 50 51 /* Frees up the mem allocated for this ring buffer operation */ 52 void ring_buffer_deinit(void *ctx); 53 54 /* Writes writes length of bytes from buf to ring buffer */ 55 enum rb_status rb_write(void *ctx, u8 *buf, size_t length, int overwrite); 56 57 /* Tries to read max_length of bytes from ring buffer to buf 58 * and returns actual length of bytes read from ring buffer 59 */ 60 size_t rb_read(void *ctx, u8 *buf, size_t max_length); 61 62 /* A buffer with possible maximum of bytes that can be read 63 * from a single buffer of ring buffer 64 * Ring buffer module looses the ownership of the buffer returned by this api, 65 * which means the caller has to make sure to free the buffer returned. 66 */ 67 u8 *rb_get_read_buf(void *ctx, size_t *length); 68 69 /* calls callback whenever ring_buffer reaches percent percentage of it'ss 70 * full size 71 */ 72 void rb_config_threshold(void *ctx, 73 unsigned int num_min_bytes, 74 threshold_call_back callback, 75 void *cb_ctx); 76 77 /* Get the current status of ring buffer */ 78 void rb_get_stats(void *ctx, struct rb_stats *rbs); 79 80 #endif /* __RING_BUFFER_H */ 81
