s390/cpum_sf: save TOD clock base in SDBs for time conversion

Processing the samples in the AUX-area by perf requires the computation
of respective time stamps.  The time stamps used by perf are based on
the monotonic clock.  To convert the TOD clock value contained in an
SDB to a monotonic clock value, the TOD clock base is required.  Hence,
also save the TOD clock base in the SDB.

Suggested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/cpu_mf.h b/arch/s390/include/asm/cpu_mf.h
index de023a9a88ca8e35bad7244977af02db2b20c277..bf2cbff926ef8ca60ebccb3c6362ae0323b04503 100644 (file)
--- a/arch/s390/include/asm/cpu_mf.h
+++ b/arch/s390/include/asm/cpu_mf.h
@@ -2,7 +2,7 @@
 /*
  * CPU-measurement facilities
  *
- *  Copyright IBM Corp. 2012
+ *  Copyright IBM Corp. 2012, 2018
  *  Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
  *            Jan Glauber <jang@linux.vnet.ibm.com>
  */
@@ -139,8 +139,14 @@ struct hws_trailer_entry {
        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 */
-       unsigned long long progusage2;   /*                                   */
+       union {                          /* 48 - reserved for programming use */
+               struct {
+                       unsigned int clock_base:1; /* in progusage2 */
+                       unsigned long long progusage1:63;
+                       unsigned long long progusage2;
+               };
+               unsigned long long progusage[2];
+       };
 } __packed;
 
 /* Load program parameter */

diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index 0292d68e7dded707496b7090c9b2d7377aab8b2b..cb198d4a6dca7566b0cfba4f34854f9b6074f972 100644 (file)
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -2,7 +2,7 @@
 /*
  * Performance event support for the System z CPU-measurement Sampling Facility
  *
- * Copyright IBM Corp. 2013
+ * Copyright IBM Corp. 2013, 2018
  * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
  */
 #define KMSG_COMPONENT "cpum_sf"
@@ -1587,6 +1587,17 @@ static void aux_buffer_free(void *data)
                            "%lu SDBTs\n", num_sdbt);
 }
 
+static void aux_sdb_init(unsigned long sdb)
+{
+       struct hws_trailer_entry *te;
+
+       te = (struct hws_trailer_entry *)trailer_entry_ptr(sdb);
+
+       /* Save clock base */
+       te->clock_base = 1;
+       memcpy(&te->progusage2, &tod_clock_base[1], 8);
+}
+
 /*
  * aux_buffer_setup() - Setup AUX buffer for diagnostic mode sampling
  * @cpu:       On which to allocate, -1 means current
@@ -1666,6 +1677,7 @@ static void *aux_buffer_setup(int cpu, void **pages, int nr_pages,
                /* Tail is the entry in a SDBT */
                *tail = (unsigned long)pages[i];
                aux->sdb_index[i] = (unsigned long)pages[i];
+               aux_sdb_init((unsigned long)pages[i]);
        }
        sfb->num_sdb = nr_pages;