oprofile: adding cpu buffer r/w access functions

This is in preparation for changes in the cpu buffer implementation.

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

3 files changed, 22 insertions, 12 deletions

diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index 7d61ae8ee8cf..44f676c8a51d 100644
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -331,10 +331,8 @@ static void add_trace_begin(void)
 
 #define IBS_FETCH_CODE_SIZE     2
 #define IBS_OP_CODE_SIZE        5
-#define IBS_EIP(offset)                         \
-        (((struct op_sample *)&cpu_buf->buffer[(offset)])->eip)
-#define IBS_EVENT(offset)                               \
-        (((struct op_sample *)&cpu_buf->buffer[(offset)])->event)
+#define IBS_EIP(cpu_buf)        ((cpu_buffer_read_entry(cpu_buf))->eip)
+#define IBS_EVENT(cpu_buf)      ((cpu_buffer_read_entry(cpu_buf))->event)
 
 /*
  * Add IBS fetch and op entries to event buffer
@@ -349,10 +347,10 @@ static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code,
 
         increment_tail(cpu_buf);        /* move to RIP entry */
 
-        rip = IBS_EIP(cpu_buf->tail_pos);
+        rip = IBS_EIP(cpu_buf);
 
 #ifdef __LP64__
-        rip += IBS_EVENT(cpu_buf->tail_pos) << 32;
+        rip += IBS_EVENT(cpu_buf) << 32;
 #endif
 
         if (mm) {
@@ -376,8 +374,8 @@ static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code,
         add_event_entry(offset);        /* Offset from Dcookie */
 
         /* we send the Dcookie offset, but send the raw Linear Add also*/
-        add_event_entry(IBS_EIP(cpu_buf->tail_pos));
-        add_event_entry(IBS_EVENT(cpu_buf->tail_pos));
+        add_event_entry(IBS_EIP(cpu_buf));
+        add_event_entry(IBS_EVENT(cpu_buf));
 
         if (code == IBS_FETCH_CODE)
                 count = IBS_FETCH_CODE_SIZE;    /*IBS FETCH is 2 int64s*/
@@ -386,8 +384,8 @@ static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code,
 
         for (i = 0; i < count; i++) {
                 increment_tail(cpu_buf);
-                add_event_entry(IBS_EIP(cpu_buf->tail_pos));
-                add_event_entry(IBS_EVENT(cpu_buf->tail_pos));
+                add_event_entry(IBS_EIP(cpu_buf));
+                add_event_entry(IBS_EVENT(cpu_buf));
         }
 }
 
@@ -584,7 +582,7 @@ void sync_buffer(int cpu)
 #else
         while (get_slots(cpu_buf)) {
 #endif
-                struct op_sample *s = &cpu_buf->buffer[cpu_buf->tail_pos];
+                struct op_sample *s = cpu_buffer_read_entry(cpu_buf);
 
                 if (is_code(s->eip)) {
                         switch (s->event) {
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 2c4d54187b90..7e5e650e409f 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -168,7 +168,7 @@ static inline void
 add_sample(struct oprofile_cpu_buffer *cpu_buf,
            unsigned long pc, unsigned long event)
 {
-        struct op_sample *entry = &cpu_buf->buffer[cpu_buf->head_pos];
+        struct op_sample *entry = cpu_buffer_write_entry(cpu_buf);
         entry->eip = pc;
         entry->event = event;
         increment_head(cpu_buf);
diff --git a/drivers/oprofile/cpu_buffer.h b/drivers/oprofile/cpu_buffer.h
index d3cc26264db5..08706991fdd2 100644
--- a/drivers/oprofile/cpu_buffer.h
+++ b/drivers/oprofile/cpu_buffer.h
@@ -52,6 +52,18 @@ DECLARE_PER_CPU(struct oprofile_cpu_buffer, cpu_buffer);
 
 void cpu_buffer_reset(struct oprofile_cpu_buffer *cpu_buf);
 
+static inline
+struct op_sample *cpu_buffer_write_entry(struct oprofile_cpu_buffer *cpu_buf)
+{
+        return &cpu_buf->buffer[cpu_buf->head_pos];
+}
+
+static inline
+struct op_sample *cpu_buffer_read_entry(struct oprofile_cpu_buffer *cpu_buf)
+{
+        return &cpu_buf->buffer[cpu_buf->tail_pos];
+}
+
 /* transient events for the CPU buffer -> event buffer */
 #define CPU_IS_KERNEL 1
 #define CPU_TRACE_BEGIN 2