s390/cpum_sf: Add helper to read TOD from trailer entries

The trailer entry contains a timestamp of the time when the sample-data-block
became full.  The timestamp specifies a TOD (time-of-day) value in either the
STCK or STCKE format.

Provide a helper function to return the TOD value depending on the setting of
time format indicator.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 13 insertions, 3 deletions

diff --git a/arch/s390/include/asm/cpu_mf.h b/arch/s390/include/asm/cpu_mf.h
index b0b3059b8d64..09dc5facc0bc 100644
--- a/arch/s390/include/asm/cpu_mf.h
+++ b/arch/s390/include/asm/cpu_mf.h
@@ -125,8 +125,7 @@ struct hws_trailer_entry {
                 unsigned long long flags;       /* 0 - 63: All indicators     */
         };
         unsigned long long overflow;     /* 64 - sample Overflow count        */
-        unsigned long long timestamp;    /* 16 - time-stamp                   */
-        unsigned long long timestamp1;   /*                                   */
+        unsigned char timestamp[16];     /* 16 - 31 timestamp                 */
         unsigned long long reserved1;    /* 32 -Reserved                      */
         unsigned long long reserved2;    /*                                   */
         unsigned long long progusage1;   /* 48 - reserved for programming use */
@@ -232,6 +231,17 @@ static inline unsigned long sample_rate_to_freq(struct hws_qsi_info_block *qsi,
 #define SDB_TE_ALERT_REQ_MASK   0x4000000000000000UL
 #define SDB_TE_BUFFER_FULL_MASK 0x8000000000000000UL
 
+/* Return TOD timestamp contained in an trailer entry */
+static inline unsigned long long trailer_timestamp(struct hws_trailer_entry *te)
+{
+        /* TOD in STCKE format */
+        if (te->t)
+                return *((unsigned long long *) &te->timestamp[1]);
+
+        /* TOD in STCK format */
+        return *((unsigned long long *) &te->timestamp[0]);
+}
+
 /* Return pointer to trailer entry of an sample data block */
 static inline unsigned long *trailer_entry_ptr(unsigned long v)
 {
diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index 9202f2858894..3ab7e67ee2e4 100644
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -981,7 +981,7 @@ static void hw_perf_event_update(struct perf_event *event, int flush_all)
                 debug_sprintf_event(sfdbg, 6, "hw_perf_event_update: sdbt=%p "
                                     "overflow=%llu timestamp=0x%llx\n",
                                     sdbt, te->overflow,
-                                    (te->f) ? te->timestamp : 0ULL);
+                                    (te->f) ? trailer_timestamp(te) : 0ULL);
 
                 /* Collect all samples from a single sample-data-block and
                  * flag if an (perf) event overflow happened.  If so, the PMU