x86/oprofile: add IBS support for AMD CPUs, IBS buffer handling routines

This patchset supports the new profiling hardware available in the
latest AMD CPUs in the oProfile driver.

Signed-off-by: Barry Kasindorf <barry.kasindorf@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 71 insertions, 1 deletions

diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index 615929f6f0c2..e1782d2df09f 100644
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -5,6 +5,7 @@
  * @remark Read the file COPYING
  *
  * @author John Levon <levon@movementarian.org>
+ * @author Barry Kasindorf
  *
  * This is the core of the buffer management. Each
  * CPU buffer is processed and entered into the
@@ -272,7 +273,7 @@ static void increment_tail(struct oprofile_cpu_buffer *b)
 {
         unsigned long new_tail = b->tail_pos + 1;
 
-        rmb();
+        rmb();  /* be sure fifo pointers are synchromized */
 
         if (new_tail < b->buffer_size)
                 b->tail_pos = new_tail;
@@ -327,6 +328,67 @@ static void add_trace_begin(void)
         add_event_entry(TRACE_BEGIN_CODE);
 }
 
+#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)
+
+/*
+ * Add IBS fetch and op entries to event buffer
+ */
+static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code,
+        int in_kernel, struct mm_struct *mm)
+{
+        unsigned long rip;
+        int i, count;
+        unsigned long ibs_cookie = 0;
+        off_t offset;
+
+        increment_tail(cpu_buf);        /* move to RIP entry */
+
+        rip = IBS_EIP(cpu_buf->tail_pos);
+
+#ifdef __LP64__
+        rip += IBS_EVENT(cpu_buf->tail_pos) << 32;
+#endif
+
+        if (mm) {
+                ibs_cookie = lookup_dcookie(mm, rip, &offset);
+
+                if (ibs_cookie == NO_COOKIE)
+                        offset = rip;
+                if (ibs_cookie == INVALID_COOKIE) {
+                        atomic_inc(&oprofile_stats.sample_lost_no_mapping);
+                        offset = rip;
+                }
+                if (ibs_cookie != last_cookie) {
+                        add_cookie_switch(ibs_cookie);
+                        last_cookie = ibs_cookie;
+                }
+        } else
+                offset = rip;
+
+        add_event_entry(ESCAPE_CODE);
+        add_event_entry(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));
+
+        if (code == IBS_FETCH_CODE)
+                count = IBS_FETCH_CODE_SIZE;    /*IBS FETCH is 2 int64s*/
+        else
+                count = IBS_OP_CODE_SIZE;       /*IBS OP is 5 int64s*/
+
+        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));
+        }
+}
 
 static void add_sample_entry(unsigned long offset, unsigned long event)
 {
@@ -524,6 +586,14 @@ void sync_buffer(int cpu)
                         } else if (s->event == CPU_TRACE_BEGIN) {
                                 state = sb_bt_start;
                                 add_trace_begin();
+                        } else if (s->event == IBS_FETCH_BEGIN) {
+                                state = sb_bt_start;
+                                add_ibs_begin(cpu_buf,
+                                        IBS_FETCH_CODE, in_kernel, mm);
+                        } else if (s->event == IBS_OP_BEGIN) {
+                                state = sb_bt_start;
+                                add_ibs_begin(cpu_buf,
+                                        IBS_OP_CODE, in_kernel, mm);
                         } else {
                                 struct mm_struct *oldmm = mm;