include/linux/simple_ring_buffer.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_SIMPLE_RING_BUFFER_H
   3 #define _LINUX_SIMPLE_RING_BUFFER_H
   4
   5 #include <linux/list.h>
   6 #include <linux/ring_buffer.h>
   7 #include <linux/ring_buffer_types.h>
   8 #include <linux/types.h>
   9
  10 /*
  11  * Ideally those struct would stay private but the caller needs to know
  12  * the allocation size for simple_ring_buffer_init().
  13  */
  14 struct simple_buffer_page {
  15         struct list_head        link;
  16         struct buffer_data_page *page;
  17         u64                     entries;
  18         u32                     write;
  19         u32                     id;
  20 };
  21
  22 struct simple_rb_per_cpu {
  23         struct simple_buffer_page       *tail_page;
  24         struct simple_buffer_page       *reader_page;
  25         struct simple_buffer_page       *head_page;
  26         struct simple_buffer_page       *bpages;
  27         struct trace_buffer_meta        *meta;
  28         u32                             nr_pages;
  29
  30 #define SIMPLE_RB_UNAVAILABLE   0
  31 #define SIMPLE_RB_READY         1
  32 #define SIMPLE_RB_WRITING       2
  33         u32                             status;
  34
  35         u64                             last_overrun;
  36         u64                             write_stamp;
  37
  38         struct simple_rb_cbs            *cbs;
  39 };
  40
  41 int simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, struct simple_buffer_page *bpages,
  42                             const struct ring_buffer_desc *desc);
  43
  44 void simple_ring_buffer_unload(struct simple_rb_per_cpu *cpu_buffer);
  45
  46 void *simple_ring_buffer_reserve(struct simple_rb_per_cpu *cpu_buffer, unsigned long length,
  47                                  u64 timestamp);
  48
  49 void simple_ring_buffer_commit(struct simple_rb_per_cpu *cpu_buffer);
  50
  51 int simple_ring_buffer_enable_tracing(struct simple_rb_per_cpu *cpu_buffer, bool enable);
  52
  53 int simple_ring_buffer_reset(struct simple_rb_per_cpu *cpu_buffer);
  54
  55 int simple_ring_buffer_swap_reader_page(struct simple_rb_per_cpu *cpu_buffer);
  56
  57 int simple_ring_buffer_init_mm(struct simple_rb_per_cpu *cpu_buffer,
  58                                struct simple_buffer_page *bpages,
  59                                const struct ring_buffer_desc *desc,
  60                                void *(*load_page)(unsigned long va),
  61                                void (*unload_page)(void *va));
  62
  63 void simple_ring_buffer_unload_mm(struct simple_rb_per_cpu *cpu_buffer,
  64                                   void (*unload_page)(void *));
  65 #endif