perf: Split up buffer handling from core code
And create the internal perf events header.
v2: Keep an internal inlined perf_output_copy()
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Stephane Eranian <eranian@google.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1305827704-5607-1-git-send-email-fweisbec@gmail.com
[ v3: use clearer 'ring_buffer' and 'rb' naming ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
new file mode 100644
index 0000000..114f27f
--- /dev/null
+++ b/kernel/events/internal.h
@@ -0,0 +1,97 @@
+#ifndef _KERNEL_EVENTS_INTERNAL_H
+#define _KERNEL_EVENTS_INTERNAL_H
+
+#define RING_BUFFER_WRITABLE 0x01
+
+struct ring_buffer {
+ atomic_t refcount;
+ struct rcu_head rcu_head;
+#ifdef CONFIG_PERF_USE_VMALLOC
+ struct work_struct work;
+ int page_order; /* allocation order */
+#endif
+ int nr_pages; /* nr of data pages */
+ int writable; /* are we writable */
+
+ atomic_t poll; /* POLL_ for wakeups */
+
+ local_t head; /* write position */
+ local_t nest; /* nested writers */
+ local_t events; /* event limit */
+ local_t wakeup; /* wakeup stamp */
+ local_t lost; /* nr records lost */
+
+ long watermark; /* wakeup watermark */
+
+ struct perf_event_mmap_page *user_page;
+ void *data_pages[0];
+};
+
+
+extern void rb_free(struct ring_buffer *rb);
+extern struct ring_buffer *
+rb_alloc(int nr_pages, long watermark, int cpu, int flags);
+extern void perf_event_wakeup(struct perf_event *event);
+
+extern void
+perf_event_header__init_id(struct perf_event_header *header,
+ struct perf_sample_data *data,
+ struct perf_event *event);
+extern void
+perf_event__output_id_sample(struct perf_event *event,
+ struct perf_output_handle *handle,
+ struct perf_sample_data *sample);
+
+extern struct page *
+perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
+
+#ifdef CONFIG_PERF_USE_VMALLOC
+/*
+ * Back perf_mmap() with vmalloc memory.
+ *
+ * Required for architectures that have d-cache aliasing issues.
+ */
+
+static inline int page_order(struct ring_buffer *rb)
+{
+ return rb->page_order;
+}
+
+#else
+
+static inline int page_order(struct ring_buffer *rb)
+{
+ return 0;
+}
+#endif
+
+static unsigned long perf_data_size(struct ring_buffer *rb)
+{
+ return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
+}
+
+static inline void
+__output_copy(struct perf_output_handle *handle,
+ const void *buf, unsigned int len)
+{
+ do {
+ unsigned long size = min_t(unsigned long, handle->size, len);
+
+ memcpy(handle->addr, buf, size);
+
+ len -= size;
+ handle->addr += size;
+ buf += size;
+ handle->size -= size;
+ if (!handle->size) {
+ struct ring_buffer *rb = handle->rb;
+
+ handle->page++;
+ handle->page &= rb->nr_pages - 1;
+ handle->addr = rb->data_pages[handle->page];
+ handle->size = PAGE_SIZE << page_order(rb);
+ }
+ } while (len);
+}
+
+#endif /* _KERNEL_EVENTS_INTERNAL_H */
