diff options
| author | Vincent Donnefort <vdonnefort@google.com> | 2026-03-09 16:24:51 +0000 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2026-03-09 12:33:53 -0400 |
| commit | 96e43537af5461b26f50904c6055046ba65d742f (patch) | |
| tree | fcd2051d9a97fb7231983bc727dd3098d76f562e /include/linux/trace_remote.h | |
| parent | fbd1743ecba11ea163920279bc16263d79bb0929 (diff) | |
tracing: Introduce trace remotes
A trace remote relies on ring-buffer remotes to read and control
compatible tracing buffers, written by entity such as firmware or
hypervisor.
Add a Tracefs directory remotes/ that contains all instances of trace
remotes. Each instance follows the same hierarchy as any other to ease
the support by existing user-space tools.
This currently does not provide any event support, which will come
later.
Link: https://patch.msgid.link/20260309162516.2623589-6-vdonnefort@google.com
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'include/linux/trace_remote.h')
| -rw-r--r-- | include/linux/trace_remote.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/include/linux/trace_remote.h b/include/linux/trace_remote.h new file mode 100644 index 000000000000..65b7e7b8267c --- /dev/null +++ b/include/linux/trace_remote.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_TRACE_REMOTE_H +#define _LINUX_TRACE_REMOTE_H + +#include <linux/ring_buffer.h> + +/** + * struct trace_remote_callbacks - Callbacks used by Tracefs to control the remote + * @load_trace_buffer: Called before Tracefs accesses the trace buffer for the first + * time. Must return a &trace_buffer_desc + * (most likely filled with trace_remote_alloc_buffer()) + * @unload_trace_buffer: + * Called once Tracefs has no use for the trace buffer + * (most likely call trace_remote_free_buffer()) + * @enable_tracing: Called on Tracefs tracing_on. It is expected from the + * remote to allow writing. + * @swap_reader_page: Called when Tracefs consumes a new page from a + * ring-buffer. It is expected from the remote to isolate a + * new reader-page from the @cpu ring-buffer. + */ +struct trace_remote_callbacks { + struct trace_buffer_desc *(*load_trace_buffer)(unsigned long size, void *priv); + void (*unload_trace_buffer)(struct trace_buffer_desc *desc, void *priv); + int (*enable_tracing)(bool enable, void *priv); + int (*swap_reader_page)(unsigned int cpu, void *priv); +}; + +int trace_remote_register(const char *name, struct trace_remote_callbacks *cbs, void *priv); + +int trace_remote_alloc_buffer(struct trace_buffer_desc *desc, size_t desc_size, size_t buffer_size, + const struct cpumask *cpumask); + +void trace_remote_free_buffer(struct trace_buffer_desc *desc); + +#endif |