/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _TRACE_MMAP_H_
#define _TRACE_MMAP_H_
#include <linux/types.h>
/**
* struct trace_buffer_meta - Ring-buffer Meta-page description
* @meta_page_size: Size of this meta-page.
* @meta_struct_len: Size of this structure.
* @subbuf_size: Size of each sub-buffer.
* @nr_subbufs: Number of subbfs in the ring-buffer, including the reader.
* @reader.lost_events: Number of events lost at the time of the reader swap.
* @reader.id: subbuf ID of the current reader. ID range [0 : @nr_subbufs - 1]
* @reader.read: Number of bytes read on the reader subbuf.
* @flags: Placeholder for now, 0 until new features are supported.
* @entries: Number of entries in the ring-buffer.
* @overrun: Number of entries lost in the ring-buffer.
* @read: Number of entries that have been read.
* @Reserved1: Internal use only.
* @Reserved2: Internal use only.
*/
struct trace_buffer_meta {
__u32 meta_page_size;
__u32 meta_struct_len;
__u32 subbuf_size;
__u32 nr_subbufs;
struct {
__u64 lost_events;
__u32 id;
__u32 read;
} reader;
__u64 flags;
__u64 entries;
__u64 overrun;
__u64 read;
__u64 Reserved1;
__u64 Reserved2;
};
#define TRACE_MMAP_IOCTL_GET_READER _IO('R', 0x20)
#endif /* _TRACE_MMAP_H_ */