oprofile: add op_cpu_buffer_add_data()

This function can be used to attach data to a sample. It returns the
remaining free buffer size that has been reserved with
op_cpu_buffer_write_reserve().

Signed-off-by: Robert Richter <robert.richter@amd.com>

2 files changed, 13 insertions, 1 deletions

diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index e859d23cfc57..1b6590746be4 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -258,7 +258,7 @@ op_add_code(struct oprofile_cpu_buffer *cpu_buf, unsigned long backtrace,
         sample->event = flags;
 
         if (size)
-                sample->data[0] = (unsigned long)task;
+                op_cpu_buffer_add_data(&entry, (unsigned long)task);
 
         op_cpu_buffer_write_commit(&entry);
 
diff --git a/drivers/oprofile/cpu_buffer.h b/drivers/oprofile/cpu_buffer.h
index e634dcf2f26f..e178dd2799c4 100644
--- a/drivers/oprofile/cpu_buffer.h
+++ b/drivers/oprofile/cpu_buffer.h
@@ -78,6 +78,18 @@ int op_cpu_buffer_write_commit(struct op_entry *entry);
 struct op_sample *op_cpu_buffer_read_entry(struct op_entry *entry, int cpu);
 unsigned long op_cpu_buffer_entries(int cpu);
 
+/* returns the remaining free size of data in the entry */
+static inline
+int op_cpu_buffer_add_data(struct op_entry *entry, unsigned long val)
+{
+        if (!entry->size)
+                return 0;
+        *entry->data = val;
+        entry->size--;
+        entry->data++;
+        return entry->size;
+}
+
 /* extra data flags */
 #define KERNEL_CTX_SWITCH       (1UL << 0)
 #define IS_KERNEL               (1UL << 1)