s390/cpum_sf: Add raw data sampling to support the diagnostic-sampling function

Also support the diagnostic-sampling function in addition to the basic-sampling
function.  Diagnostic-sampling data entries contain hardware model specific
sampling data and additional programs are required to analyze the data.

To deliver diagnostic-sampling, as well, as basis-sampling data entries to user
space, introduce support for sampling "raw data".  If this particular perf
sampling type (PERF_SAMPLE_RAW) is used, sampling data entries are copied
to user space.  External programs can then analyze these data.

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

5 files changed, 377 insertions, 96 deletions

diff --git a/arch/s390/include/asm/cpu_mf.h b/arch/s390/include/asm/cpu_mf.h
index 09dc5facc0bc..cb700d54bd83 100644
--- a/arch/s390/include/asm/cpu_mf.h
+++ b/arch/s390/include/asm/cpu_mf.h
@@ -59,13 +59,15 @@ struct cpumf_ctr_info {
 /* QUERY SAMPLING INFORMATION block */
 struct hws_qsi_info_block {         /* Bit(s) */
         unsigned int b0_13:14;      /* 0-13: zeros                       */
-        unsigned int as:1;          /* 14: sampling authorisation control*/
-        unsigned int b15_21:7;      /* 15-21: zeros                      */
-        unsigned int es:1;          /* 22: sampling enable control       */
-        unsigned int b23_29:7;      /* 23-29: zeros                      */
-        unsigned int cs:1;          /* 30: sampling activation control   */
-        unsigned int:1;             /* 31: reserved                      */
-        unsigned int bsdes:16;      /* 4-5: size of basic sampling entry      */
+        unsigned int as:1;          /* 14: basic-sampling authorization  */
+        unsigned int ad:1;          /* 15: diag-sampling authorization   */
+        unsigned int b16_21:6;      /* 16-21: zeros                      */
+        unsigned int es:1;          /* 22: basic-sampling enable control */
+        unsigned int ed:1;          /* 23: diag-sampling enable control  */
+        unsigned int b24_29:6;      /* 24-29: zeros                      */
+        unsigned int cs:1;          /* 30: basic-sampling activation control */
+        unsigned int cd:1;          /* 31: diag-sampling activation control */
+        unsigned int bsdes:16;      /* 4-5: size of basic sampling entry */
         unsigned int dsdes:16;      /* 6-7: size of diagnostic sampling entry */
         unsigned long min_sampl_rate; /* 8-15: minimum sampling interval */
         unsigned long max_sampl_rate; /* 16-23: maximum sampling interval*/
@@ -82,10 +84,11 @@ struct hws_lsctl_request_block {
         unsigned int s:1;           /* 0: maximum buffer indicator       */
         unsigned int h:1;           /* 1: part. level reserved for VM use*/
         unsigned long long b2_53:52;/* 2-53: zeros                       */
-        unsigned int es:1;          /* 54: sampling enable control       */
-        unsigned int b55_61:7;      /* 55-61: - zeros                    */
-        unsigned int cs:1;          /* 62: sampling activation control   */
-        unsigned int b63:1;         /* 63: zero                          */
+        unsigned int es:1;          /* 54: basic-sampling enable control */
+        unsigned int ed:1;          /* 55: diag-sampling enable control  */
+        unsigned int b56_61:6;      /* 56-61: - zeros                    */
+        unsigned int cs:1;          /* 62: basic-sampling activation control */
+        unsigned int cd:1;          /* 63: diag-sampling activation control  */
         unsigned long interval;     /* 8-15: sampling interval           */
         unsigned long tear;         /* 16-23: TEAR contents              */
         unsigned long dear;         /* 24-31: DEAR contents              */
@@ -96,8 +99,7 @@ struct hws_lsctl_request_block {
         unsigned long rsvrd4;       /* reserved                          */
 } __packed;
 
-
-struct hws_data_entry {
+struct hws_basic_entry {
         unsigned int def:16;        /* 0-15  Data Entry Format           */
         unsigned int R:4;           /* 16-19 reserved                    */
         unsigned int U:4;           /* 20-23 Number of unique instruct.  */
@@ -114,6 +116,18 @@ struct hws_data_entry {
         unsigned long long hpp;     /* Host Program Parameter            */
 } __packed;
 
+struct hws_diag_entry {
+        unsigned int def:16;        /* 0-15  Data Entry Format           */
+        unsigned int R:14;          /* 16-19 and 20-30 reserved          */
+        unsigned int I:1;           /* 31 entry valid or invalid         */
+        u8           data[];        /* Machine-dependent sample data     */
+} __packed;
+
+struct hws_combined_entry {
+        struct hws_basic_entry  basic;  /* Basic-sampling data entry */
+        struct hws_diag_entry   diag;   /* Diagnostic-sampling data entry */
+} __packed;
+
 struct hws_trailer_entry {
         union {
                 struct {
diff --git a/arch/s390/include/asm/perf_event.h b/arch/s390/include/asm/perf_event.h
index 7667bde37dcb..bd4573f1d65c 100644
--- a/arch/s390/include/asm/perf_event.h
+++ b/arch/s390/include/asm/perf_event.h
@@ -52,15 +52,39 @@ struct perf_sf_sde_regs {
 #define PERF_CPUM_CF_MAX_CTR            256
 
 /* Perf PMU definitions for the sampling facility */
-#define PERF_CPUM_SF_MAX_CTR            1
-#define PERF_EVENT_CPUM_SF              0xB0000UL       /* Raw event ID */
+#define PERF_CPUM_SF_MAX_CTR            2
+#define PERF_EVENT_CPUM_SF              0xB0000UL /* Event: Basic-sampling */
+#define PERF_EVENT_CPUM_SF_DIAG         0xBD000UL /* Event: Combined-sampling */
+#define PERF_CPUM_SF_BASIC_MODE         0x0001    /* Basic-sampling flag */
+#define PERF_CPUM_SF_DIAG_MODE          0x0002    /* Diagnostic-sampling flag */
+#define PERF_CPUM_SF_MODE_MASK          (PERF_CPUM_SF_BASIC_MODE| \
+                                         PERF_CPUM_SF_DIAG_MODE)
 
 #define REG_NONE                0
 #define REG_OVERFLOW            1
 #define OVERFLOW_REG(hwc)       ((hwc)->extra_reg.config)
 #define SFB_ALLOC_REG(hwc)      ((hwc)->extra_reg.alloc)
+#define RAWSAMPLE_REG(hwc)      ((hwc)->config)
 #define TEAR_REG(hwc)           ((hwc)->last_tag)
 #define SAMPL_RATE(hwc)         ((hwc)->event_base)
+#define SAMPL_FLAGS(hwc)        ((hwc)->config_base)
+#define SAMPL_DIAG_MODE(hwc)    (SAMPL_FLAGS(hwc) & PERF_CPUM_SF_DIAG_MODE)
+
+/* Structure for sampling data entries to be passed as perf raw sample data
+ * to user space.  Note that raw sample data must be aligned and, thus, might
+ * be padded with zeros.
+ */
+struct sf_raw_sample {
+#define SF_RAW_SAMPLE_BASIC     PERF_CPUM_SF_BASIC_MODE
+#define SF_RAW_SAMPLE_DIAG      PERF_CPUM_SF_DIAG_MODE
+        u64                     format;
+        u32                      size;    /* Size of sf_raw_sample */
+        u16                     bsdes;    /* Basic-sampling data entry size */
+        u16                     dsdes;    /* Diagnostic-sampling data entry size */
+        struct hws_basic_entry  basic;    /* Basic-sampling data entry */
+        struct hws_diag_entry    diag;    /* Diagnostic-sampling data entry */
+        u8                  padding[];    /* Padding to next multiple of 8 */
+} __packed;
 
 /* Perf hardware reserve and release functions */
 int perf_reserve_sampling(void);
diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index 28fa2f235158..b4ec058c4f10 100644
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -17,6 +17,7 @@
 #include <linux/percpu.h>
 #include <linux/notifier.h>
 #include <linux/export.h>
+#include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/moduleparam.h>
 #include <asm/cpu_mf.h>
@@ -31,8 +32,8 @@
 #define CPUM_SF_MIN_SDBT        1
 
 /* Number of sample-data-blocks per sample-data-block-table (SDBT):
- * The table contains SDB origin (8 bytes) and one SDBT origin that
- * points to the next table.
+ * A table contains SDB pointers (8 bytes) and one table-link entry
+ * that points to the origin of the next SDBT.
  */
 #define CPUM_SF_SDB_PER_TABLE   ((PAGE_SIZE - 8) / 8)
 
@@ -48,8 +49,11 @@ static inline int require_table_link(const void *sdbt)
 
 /* Minimum and maximum sampling buffer sizes:
  *
- * This number represents the maximum size of the sampling buffer
- * taking the number of sample-data-block-tables into account.
+ * This number represents the maximum size of the sampling buffer taking
+ * the number of sample-data-block-tables into account.  Note that these
+ * numbers apply to the basic-sampling function only.
+ * The maximum number of SDBs is increased by CPUM_SF_SDB_DIAG_FACTOR if
+ * the diagnostic-sampling function is active.
  *
  * Sampling buffer size         Buffer characteristics
  * ---------------------------------------------------
@@ -63,6 +67,7 @@ static inline int require_table_link(const void *sdbt)
  */
 static unsigned long __read_mostly CPUM_SF_MIN_SDB = 15;
 static unsigned long __read_mostly CPUM_SF_MAX_SDB = 8176;
+static unsigned long __read_mostly CPUM_SF_SDB_DIAG_FACTOR = 1;
 
 struct sf_buffer {
         unsigned long    *sdbt;     /* Sample-data-block-table origin */
@@ -290,8 +295,20 @@ static int alloc_sampling_buffer(struct sf_buffer *sfb, unsigned long num_sdb)
 
 static void sfb_set_limits(unsigned long min, unsigned long max)
 {
+        struct hws_qsi_info_block si;
+
         CPUM_SF_MIN_SDB = min;
         CPUM_SF_MAX_SDB = max;
+
+        memset(&si, 0, sizeof(si));
+        if (!qsi(&si))
+                CPUM_SF_SDB_DIAG_FACTOR = DIV_ROUND_UP(si.dsdes, si.bsdes);
+}
+
+static unsigned long sfb_max_limit(struct hw_perf_event *hwc)
+{
+        return SAMPL_DIAG_MODE(hwc) ? CPUM_SF_MAX_SDB * CPUM_SF_SDB_DIAG_FACTOR
+                                    : CPUM_SF_MAX_SDB;
 }
 
 static unsigned long sfb_pending_allocs(struct sf_buffer *sfb,
@@ -312,8 +329,8 @@ static int sfb_has_pending_allocs(struct sf_buffer *sfb,
 
 static void sfb_account_allocs(unsigned long num, struct hw_perf_event *hwc)
 {
-        /* Limit the number SDBs to not exceed the maximum */
-        num = min_t(unsigned long, num, CPUM_SF_MAX_SDB - SFB_ALLOC_REG(hwc));
+        /* Limit the number of SDBs to not exceed the maximum */
+        num = min_t(unsigned long, num, sfb_max_limit(hwc) - SFB_ALLOC_REG(hwc));
         if (num)
                 SFB_ALLOC_REG(hwc) += num;
 }
@@ -324,32 +341,89 @@ static void sfb_init_allocs(unsigned long num, struct hw_perf_event *hwc)
         sfb_account_allocs(num, hwc);
 }
 
-static int allocate_sdbt(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc)
+static size_t event_sample_size(struct hw_perf_event *hwc)
+{
+        struct sf_raw_sample *sfr = (struct sf_raw_sample *) RAWSAMPLE_REG(hwc);
+        size_t sample_size;
+
+        /* The sample size depends on the sampling function: The basic-sampling
+         * function must be always enabled, diagnostic-sampling function is
+         * optional.
+         */
+        sample_size = sfr->bsdes;
+        if (SAMPL_DIAG_MODE(hwc))
+                sample_size += sfr->dsdes;
+
+        return sample_size;
+}
+
+static void deallocate_buffers(struct cpu_hw_sf *cpuhw)
+{
+        if (cpuhw->sfb.sdbt)
+                free_sampling_buffer(&cpuhw->sfb);
+}
+
+static int allocate_buffers(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc)
 {
-        unsigned long n_sdb, freq;
-        unsigned long factor;
+        unsigned long n_sdb, freq, factor;
+        size_t sfr_size, sample_size;
+        struct sf_raw_sample *sfr;
+
+        /* Allocate raw sample buffer
+         *
+         *    The raw sample buffer is used to temporarily store sampling data
+         *    entries for perf raw sample processing.  The buffer size mainly
+         *    depends on the size of diagnostic-sampling data entries which is
+         *    machine-specific.  The exact size calculation includes:
+         *      1. The first 4 bytes of diagnostic-sampling data entries are
+         *         already reflected in the sf_raw_sample structure.  Subtract
+         *         these bytes.
+         *      2. The perf raw sample data must be 8-byte aligned (u64) and
+         *         perf's internal data size must be considered too.  So add
+         *         an additional u32 for correct alignment and subtract before
+         *         allocating the buffer.
+         *      3. Store the raw sample buffer pointer in the perf event
+         *         hardware structure.
+         */
+        sfr_size = ALIGN((sizeof(*sfr) - sizeof(sfr->diag) + cpuhw->qsi.dsdes) +
+                         sizeof(u32), sizeof(u64));
+        sfr_size -= sizeof(u32);
+        sfr = kzalloc(sfr_size, GFP_KERNEL);
+        if (!sfr)
+                return -ENOMEM;
+        sfr->size = sfr_size;
+        sfr->bsdes = cpuhw->qsi.bsdes;
+        sfr->dsdes = cpuhw->qsi.dsdes;
+        RAWSAMPLE_REG(hwc) = (unsigned long) sfr;
 
         /* Calculate sampling buffers using 4K pages
          *
-         *    1. Use frequency as input.  The samping buffer is designed for
-         *       a complete second.  This can be adjusted through the "factor"
-         *       variable.
+         *    1. Determine the sample data size which depends on the used
+         *       sampling functions, for example, basic-sampling or
+         *       basic-sampling with diagnostic-sampling.
+         *
+         *    2. Use the sampling frequency as input.  The sampling buffer is
+         *       designed for almost one second.  This can be adjusted through
+         *       the "factor" variable.
          *       In any case, alloc_sampling_buffer() sets the Alert Request
-         *       Control indicator to trigger measurement-alert to harvest
+         *       Control indicator to trigger a measurement-alert to harvest
          *       sample-data-blocks (sdb).
          *
-         *    2. Compute the number of sample-data-blocks and ensure a minimum
+         *    3. Compute the number of sample-data-blocks and ensure a minimum
          *       of CPUM_SF_MIN_SDB.  Also ensure the upper limit does not
-         *       exceed CPUM_SF_MAX_SDB.  See also the remarks for these
-         *       symbolic constants.
+         *       exceed a "calculated" maximum.  The symbolic maximum is
+         *       designed for basic-sampling only and needs to be increased if
+         *       diagnostic-sampling is active.
+         *       See also the remarks for these symbolic constants.
          *
-         *    3. Compute number of pages used for the sample-data-block-table
-         *       and ensure a minimum of CPUM_SF_MIN_SDBT (at minimum one table
-         *       to manage up to 511 sample-data-blocks).
+         *    4. Compute the number of sample-data-block-tables (SDBT) and
+         *       ensure a minimum of CPUM_SF_MIN_SDBT (one table can manage up
+         *       to 511 SDBs).
          */
+        sample_size = event_sample_size(hwc);
         freq = sample_rate_to_freq(&cpuhw->qsi, SAMPL_RATE(hwc));
         factor = 1;
-        n_sdb = DIV_ROUND_UP(freq, factor * ((PAGE_SIZE-64) / cpuhw->qsi.bsdes));
+        n_sdb = DIV_ROUND_UP(freq, factor * ((PAGE_SIZE-64) / sample_size));
         if (n_sdb < CPUM_SF_MIN_SDB)
                 n_sdb = CPUM_SF_MIN_SDB;
 
@@ -366,8 +440,10 @@ static int allocate_sdbt(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc)
                 return 0;
 
         debug_sprintf_event(sfdbg, 3,
-                            "allocate_sdbt: rate=%lu f=%lu sdb=%lu/%lu cpuhw=%p\n",
-                            SAMPL_RATE(hwc), freq, n_sdb, CPUM_SF_MAX_SDB, cpuhw);
+                            "allocate_buffers: rate=%lu f=%lu sdb=%lu/%lu"
+                            " sample_size=%lu cpuhw=%p\n",
+                            SAMPL_RATE(hwc), freq, n_sdb, sfb_max_limit(hwc),
+                            sample_size, cpuhw);
 
         return alloc_sampling_buffer(&cpuhw->sfb,
                                      sfb_pending_allocs(&cpuhw->sfb, hwc));
@@ -509,10 +585,8 @@ static void setup_pmc_cpu(void *flags)
                 if (err) {
                         pr_err("Switching off the sampling facility failed "
                                "with rc=%i\n", err);
-                } else {
-                        if (cpusf->sfb.sdbt)
-                                free_sampling_buffer(&cpusf->sfb);
-                }
+                } else
+                        deallocate_buffers(cpusf);
                 debug_sprintf_event(sfdbg, 5,
                                     "setup_pmc_cpu: released: cpuhw=%p\n", cpusf);
                 break;
@@ -550,6 +624,10 @@ static int reserve_pmc_hardware(void)
 
 static void hw_perf_event_destroy(struct perf_event *event)
 {
+        /* Free raw sample buffer */
+        if (RAWSAMPLE_REG(&event->hw))
+                kfree((void *) RAWSAMPLE_REG(&event->hw));
+
         /* Release PMC if this is the last perf event */
         if (!atomic_add_unless(&num_events, -1, 1)) {
                 mutex_lock(&pmc_reserve_mutex);
@@ -569,8 +647,15 @@ static void hw_init_period(struct hw_perf_event *hwc, u64 period)
 static void hw_reset_registers(struct hw_perf_event *hwc,
                                unsigned long *sdbt_origin)
 {
+        struct sf_raw_sample *sfr;
+
         /* (Re)set to first sample-data-block-table */
         TEAR_REG(hwc) = (unsigned long) sdbt_origin;
+
+        /* (Re)set raw sampling buffer register */
+        sfr = (struct sf_raw_sample *) RAWSAMPLE_REG(hwc);
+        memset(&sfr->basic, 0, sizeof(sfr->basic));
+        memset(&sfr->diag, 0, sfr->dsdes);
 }
 
 static unsigned long hw_limit_rate(const struct hws_qsi_info_block *si,
@@ -634,6 +719,20 @@ static int __hw_perf_event_init(struct perf_event *event)
                 goto out;
         }
 
+        /* Always enable basic sampling */
+        SAMPL_FLAGS(hwc) = PERF_CPUM_SF_BASIC_MODE;
+
+        /* Check if diagnostic sampling is requested.  Deny if the required
+         * sampling authorization is missing.
+         */
+        if (attr->config == PERF_EVENT_CPUM_SF_DIAG) {
+                if (!si.ad) {
+                        err = -EPERM;
+                        goto out;
+                }
+                SAMPL_FLAGS(hwc) |= PERF_CPUM_SF_DIAG_MODE;
+        }
+
         /* The sampling information (si) contains information about the
          * min/max sampling intervals and the CPU speed.  So calculate the
          * correct sampling interval and avoid the whole period adjust
@@ -679,14 +778,14 @@ static int __hw_perf_event_init(struct perf_event *event)
          */
         if (cpuhw)
                 /* Event is pinned to a particular CPU */
-                err = allocate_sdbt(cpuhw, hwc);
+                err = allocate_buffers(cpuhw, hwc);
         else {
                 /* Event is not pinned, allocate sampling buffer on
                  * each online CPU
                  */
                 for_each_online_cpu(cpu) {
                         cpuhw = &per_cpu(cpu_hw_sf, cpu);
-                        err = allocate_sdbt(cpuhw, hwc);
+                        err = allocate_buffers(cpuhw, hwc);
                         if (err)
                                 break;
                 }
@@ -705,7 +804,8 @@ static int cpumsf_pmu_event_init(struct perf_event *event)
 
         switch (event->attr.type) {
         case PERF_TYPE_RAW:
-                if (event->attr.config != PERF_EVENT_CPUM_SF)
+                if ((event->attr.config != PERF_EVENT_CPUM_SF) &&
+                    (event->attr.config != PERF_EVENT_CPUM_SF_DIAG))
                         return -ENOENT;
                 break;
         case PERF_TYPE_HARDWARE:
@@ -786,8 +886,9 @@ static void cpumsf_pmu_enable(struct pmu *pmu)
                 return;
         }
 
-        debug_sprintf_event(sfdbg, 6, "pmu_enable: es=%i cs=%i tear=%p dear=%p\n",
-                            cpuhw->lsctl.es, cpuhw->lsctl.cs,
+        debug_sprintf_event(sfdbg, 6, "pmu_enable: es=%i cs=%i ed=%i cd=%i "
+                            "tear=%p dear=%p\n", cpuhw->lsctl.es, cpuhw->lsctl.cs,
+                            cpuhw->lsctl.ed, cpuhw->lsctl.cd,
                             (void *) cpuhw->lsctl.tear, (void *) cpuhw->lsctl.dear);
 }
 
@@ -807,6 +908,7 @@ static void cpumsf_pmu_disable(struct pmu *pmu)
         /* Switch off sampling activation control */
         inactive = cpuhw->lsctl;
         inactive.cs = 0;
+        inactive.cd = 0;
 
         err = lsctl(&inactive);
         if (err) {
@@ -867,21 +969,19 @@ static int perf_exclude_event(struct perf_event *event, struct pt_regs *regs,
  *
  * Return non-zero if an event overflow occurred.
  */
-static int perf_push_sample(struct perf_event *event,
-                            struct hws_data_entry *sample)
+static int perf_push_sample(struct perf_event *event, struct sf_raw_sample *sfr)
 {
         int overflow;
         struct pt_regs regs;
         struct perf_sf_sde_regs *sde_regs;
         struct perf_sample_data data;
+        struct perf_raw_record raw;
 
-        /* Skip samples that are invalid or for which the instruction address
-         * is not predictable.  For the latter, the wait-state bit is set.
-         */
-        if (sample->I || sample->W)
-                return 0;
-
+        /* Setup perf sample */
         perf_sample_data_init(&data, 0, event->hw.last_period);
+        raw.size = sfr->size;
+        raw.data = sfr;
+        data.raw = &raw;
 
         /* Setup pt_regs to look like an CPU-measurement external interrupt
          * using the Program Request Alert code.  The regs.int_parm_long
@@ -893,14 +993,14 @@ static int perf_push_sample(struct perf_event *event,
         regs.int_parm = CPU_MF_INT_SF_PRA;
         sde_regs = (struct perf_sf_sde_regs *) &regs.int_parm_long;
 
-        regs.psw.addr = sample->ia;
-        if (sample->T)
+        regs.psw.addr = sfr->basic.ia;
+        if (sfr->basic.T)
                 regs.psw.mask |= PSW_MASK_DAT;
-        if (sample->W)
+        if (sfr->basic.W)
                 regs.psw.mask |= PSW_MASK_WAIT;
-        if (sample->P)
+        if (sfr->basic.P)
                 regs.psw.mask |= PSW_MASK_PSTATE;
-        switch (sample->AS) {
+        switch (sfr->basic.AS) {
         case 0x0:
                 regs.psw.mask |= PSW_ASC_PRIMARY;
                 break;
@@ -922,7 +1022,7 @@ static int perf_push_sample(struct perf_event *event,
          * purposes too.
          * For now, simply use a non-zero value as guest indicator.
          */
-        if (sample->hpp)
+        if (sfr->basic.hpp)
                 sde_regs->in_guest = 1;
 
         overflow = 0;
@@ -942,51 +1042,155 @@ static void perf_event_count_update(struct perf_event *event, u64 count)
         local64_add(count, &event->count);
 }
 
+static int sample_format_is_valid(struct hws_combined_entry *sample,
+                                   unsigned int flags)
+{
+        if (likely(flags & PERF_CPUM_SF_BASIC_MODE))
+                /* Only basic-sampling data entries with data-entry-format
+                 * version of 0x0001 can be processed.
+                 */
+                if (sample->basic.def != 0x0001)
+                        return 0;
+        if (flags & PERF_CPUM_SF_DIAG_MODE)
+                /* The data-entry-format number of diagnostic-sampling data
+                 * entries can vary.  Because diagnostic data is just passed
+                 * through, do only a sanity check on the DEF.
+                 */
+                if (sample->diag.def < 0x8001)
+                        return 0;
+        return 1;
+}
+
+static int sample_is_consistent(struct hws_combined_entry *sample,
+                                unsigned long flags)
+{
+        /* This check applies only to basic-sampling data entries of potentially
+         * combined-sampling data entries.  Invalid entries cannot be processed
+         * by the PMU and, thus, do not deliver an associated
+         * diagnostic-sampling data entry.
+         */
+        if (unlikely(!(flags & PERF_CPUM_SF_BASIC_MODE)))
+                return 0;
+        /*
+         * Samples are skipped, if they are invalid or for which the
+         * instruction address is not predictable, i.e., the wait-state bit is
+         * set.
+         */
+        if (sample->basic.I || sample->basic.W)
+                return 0;
+        return 1;
+}
+
+static void reset_sample_slot(struct hws_combined_entry *sample,
+                              unsigned long flags)
+{
+        if (likely(flags & PERF_CPUM_SF_BASIC_MODE))
+                sample->basic.def = 0;
+        if (flags & PERF_CPUM_SF_DIAG_MODE)
+                sample->diag.def = 0;
+}
+
+static void sfr_store_sample(struct sf_raw_sample *sfr,
+                             struct hws_combined_entry *sample)
+{
+        if (likely(sfr->format & PERF_CPUM_SF_BASIC_MODE))
+                sfr->basic = sample->basic;
+        if (sfr->format & PERF_CPUM_SF_DIAG_MODE)
+                memcpy(&sfr->diag, &sample->diag, sfr->dsdes);
+}
+
+static void debug_sample_entry(struct hws_combined_entry *sample,
+                               struct hws_trailer_entry *te,
+                               unsigned long flags)
+{
+        debug_sprintf_event(sfdbg, 4, "hw_collect_samples: Found unknown "
+                            "sampling data entry: te->f=%i basic.def=%04x (%p)"
+                            " diag.def=%04x (%p)\n", te->f,
+                            sample->basic.def, &sample->basic,
+                            (flags & PERF_CPUM_SF_DIAG_MODE)
+                                        ? sample->diag.def : 0xFFFF,
+                            (flags & PERF_CPUM_SF_DIAG_MODE)
+                                        ?  &sample->diag : NULL);
+}
+
 /* hw_collect_samples() - Walk through a sample-data-block and collect samples
  * @event:      The perf event
  * @sdbt:       Sample-data-block table
  * @overflow:   Event overflow counter
  *
- * Walks through a sample-data-block and collects hardware sample-data that is
- * pushed to the perf event subsystem.  The overflow reports the number of
- * samples that has been discarded due to an event overflow.
+ * Walks through a sample-data-block and collects sampling data entries that are
+ * then pushed to the perf event subsystem.  Depending on the sampling function,
+ * there can be either basic-sampling or combined-sampling data entries.  A
+ * combined-sampling data entry consists of a basic- and a diagnostic-sampling
+ * data entry.  The sampling function is determined by the flags in the perf
+ * event hardware structure.  The function always works with a combined-sampling
+ * data entry but ignores the the diagnostic portion if it is not available.
+ *
+ * Note that the implementation focuses on basic-sampling data entries and, if
+ * such an entry is not valid, the entire combined-sampling data entry is
+ * ignored.
+ *
+ * The overflow variables counts the number of samples that has been discarded
+ * due to a perf event overflow.
  */
 static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt,
                                unsigned long long *overflow)
 {
-        struct hws_data_entry *sample;
-        unsigned long *trailer;
+        unsigned long flags = SAMPL_FLAGS(&event->hw);
+        struct hws_combined_entry *sample;
+        struct hws_trailer_entry *te;
+        struct sf_raw_sample *sfr;
+        size_t sample_size;
+
+        /* Prepare and initialize raw sample data */
+        sfr = (struct sf_raw_sample *) RAWSAMPLE_REG(&event->hw);
+        sfr->format = flags & PERF_CPUM_SF_MODE_MASK;
 
-        trailer = trailer_entry_ptr(*sdbt);
-        sample = (struct hws_data_entry *) *sdbt;
-        while ((unsigned long *) sample < trailer) {
+        sample_size = event_sample_size(&event->hw);
+        te = (struct hws_trailer_entry *) trailer_entry_ptr(*sdbt);
+        sample = (struct hws_combined_entry *) *sdbt;
+        while ((unsigned long *) sample < (unsigned long *) te) {
                 /* Check for an empty sample */
-                if (!sample->def)
+                if (!sample->basic.def)
                         break;
 
                 /* Update perf event period */
                 perf_event_count_update(event, SAMPL_RATE(&event->hw));
 
-                /* Check for basic sampling mode */
-                if (sample->def == 0x0001) {
+                /* Check sampling data entry */
+                if (sample_format_is_valid(sample, flags)) {
                         /* If an event overflow occurred, the PMU is stopped to
                          * throttle event delivery.  Remaining sample data is
                          * discarded.
                          */
-                        if (!*overflow)
-                                *overflow = perf_push_sample(event, sample);
-                        else
+                        if (!*overflow) {
+                                if (sample_is_consistent(sample, flags)) {
+                                        /* Deliver sample data to perf */
+                                        sfr_store_sample(sfr, sample);
+                                        *overflow = perf_push_sample(event, sfr);
+                                }
+                        } else
                                 /* Count discarded samples */
                                 *overflow += 1;
-                } else
-                        /* Sample slot is not yet written or other record */
-                        debug_sprintf_event(sfdbg, 5, "hw_collect_samples: "
-                                            "Unknown sample data entry format:"
-                                            " %i\n", sample->def);
+                } else {
+                        debug_sample_entry(sample, te, flags);
+                        /* Sample slot is not yet written or other record.
+                         *
+                         * This condition can occur if the buffer was reused
+                         * from a combined basic- and diagnostic-sampling.
+                         * If only basic-sampling is then active, entries are
+                         * written into the larger diagnostic entries.
+                         * This is typically the case for sample-data-blocks
+                         * that are not full.  Stop processing if the first
+                         * invalid format was detected.
+                         */
+                        if (!te->f)
+                                break;
+                }
 
                 /* Reset sample slot and advance to next sample */
-                sample->def = 0;
-                sample++;
+                reset_sample_slot(sample, flags);
+                sample += sample_size;
         }
 }
 
@@ -1104,6 +1308,8 @@ static void cpumsf_pmu_start(struct perf_event *event, int flags)
         perf_pmu_disable(event->pmu);
         event->hw.state = 0;
         cpuhw->lsctl.cs = 1;
+        if (SAMPL_DIAG_MODE(&event->hw))
+                cpuhw->lsctl.cd = 1;
         perf_pmu_enable(event->pmu);
 }
 
@@ -1119,6 +1325,7 @@ static void cpumsf_pmu_stop(struct perf_event *event, int flags)
 
         perf_pmu_disable(event->pmu);
         cpuhw->lsctl.cs = 0;
+        cpuhw->lsctl.cd = 0;
         event->hw.state |= PERF_HES_STOPPED;
 
         if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) {
@@ -1158,11 +1365,13 @@ static int cpumsf_pmu_add(struct perf_event *event, int flags)
 
         /* Ensure sampling functions are in the disabled state.  If disabled,
          * switch on sampling enable control. */
-        if (WARN_ON_ONCE(cpuhw->lsctl.es == 1)) {
+        if (WARN_ON_ONCE(cpuhw->lsctl.es == 1 || cpuhw->lsctl.ed == 1)) {
                 err = -EAGAIN;
                 goto out;
         }
         cpuhw->lsctl.es = 1;
+        if (SAMPL_DIAG_MODE(&event->hw))
+                cpuhw->lsctl.ed = 1;
 
         /* Set in_use flag and store event */
         event->hw.idx = 0;        /* only one sampling event per CPU supported */
@@ -1185,6 +1394,7 @@ static void cpumsf_pmu_del(struct perf_event *event, int flags)
         cpumsf_pmu_stop(event, PERF_EF_UPDATE);
 
         cpuhw->lsctl.es = 0;
+        cpuhw->lsctl.ed = 0;
         cpuhw->flags &= ~PMU_F_IN_USE;
         cpuhw->event = NULL;
 
@@ -1198,9 +1408,11 @@ static int cpumsf_pmu_event_idx(struct perf_event *event)
 }
 
 CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC, PERF_EVENT_CPUM_SF);
+CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC_DIAG, PERF_EVENT_CPUM_SF_DIAG);
 
 static struct attribute *cpumsf_pmu_events_attr[] = {
         CPUMF_EVENT_PTR(SF, SF_CYCLES_BASIC),
+        CPUMF_EVENT_PTR(SF, SF_CYCLES_BASIC_DIAG),
         NULL,
 };
 
@@ -1351,8 +1563,9 @@ static int param_set_sfb_size(const char *val, const struct kernel_param *kp)
                 return rc;
 
         sfb_set_limits(min, max);
-        pr_info("Changed sampling buffer settings: min=%lu max=%lu\n",
-                CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB);
+        pr_info("The sampling buffer limits have changed to: "
+                "min=%lu max=%lu (diag=x%lu)\n",
+                CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB, CPUM_SF_SDB_DIAG_FACTOR);
         return 0;
 }
 
@@ -1362,13 +1575,38 @@ static struct kernel_param_ops param_ops_sfb_size = {
         .get = param_get_sfb_size,
 };
 
+#define RS_INIT_FAILURE_QSI       0x0001
+#define RS_INIT_FAILURE_BSDES     0x0002
+#define RS_INIT_FAILURE_ALRT      0x0003
+#define RS_INIT_FAILURE_PERF      0x0004
+static void __init pr_cpumsf_err(unsigned int reason)
+{
+        pr_err("Sampling facility support for perf is not available: "
+               "reason=%04x\n", reason);
+}
+
 static int __init init_cpum_sampling_pmu(void)
 {
+        struct hws_qsi_info_block si;
         int err;
 
         if (!cpum_sf_avail())
                 return -ENODEV;
 
+        memset(&si, 0, sizeof(si));
+        if (qsi(&si)) {
+                pr_cpumsf_err(RS_INIT_FAILURE_QSI);
+                return -ENODEV;
+        }
+
+        if (si.bsdes != sizeof(struct hws_basic_entry)) {
+                pr_cpumsf_err(RS_INIT_FAILURE_BSDES);
+                return -EINVAL;
+        }
+
+        if (si.ad)
+                sfb_set_limits(CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB);
+
         sfdbg = debug_register(KMSG_COMPONENT, 2, 1, 80);
         if (!sfdbg)
                 pr_err("Registering for s390dbf failed\n");
@@ -1376,13 +1614,13 @@ static int __init init_cpum_sampling_pmu(void)
 
         err = register_external_interrupt(0x1407, cpumf_measurement_alert);
         if (err) {
-                pr_err("Failed to register for CPU-measurement alerts\n");
+                pr_cpumsf_err(RS_INIT_FAILURE_ALRT);
                 goto out;
         }
 
         err = perf_pmu_register(&cpumf_sampling, "cpum_sf", PERF_TYPE_RAW);
         if (err) {
-                pr_err("Failed to register cpum_sf pmu\n");
+                pr_cpumsf_err(RS_INIT_FAILURE_PERF);
                 unregister_external_interrupt(0x1407, cpumf_measurement_alert);
                 goto out;
         }
diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c
index 60a68261d091..91aa215f947f 100644
--- a/arch/s390/kernel/perf_event.c
+++ b/arch/s390/kernel/perf_event.c
@@ -139,16 +139,21 @@ static void print_debug_sf(void)
         int cpu = smp_processor_id();
 
         memset(&si, 0, sizeof(si));
-        if (qsi(&si)) {
-                pr_err("CPU[%i]: CPM_SF: qsi failed\n");
+        if (qsi(&si))
                 return;
-        }
 
-        pr_info("CPU[%i]: CPM_SF: as=%i es=%i cs=%i bsdes=%i dsdes=%i"
-                " min=%i max=%i cpu_speed=%i tear=%p dear=%p\n",
-                cpu, si.as, si.es, si.cs, si.bsdes, si.dsdes,
-                si.min_sampl_rate, si.max_sampl_rate, si.cpu_speed,
-                si.tear, si.dear);
+        pr_info("CPU[%i] CPUM_SF: basic=%i diag=%i min=%i max=%i cpu_speed=%i\n",
+                cpu, si.as, si.ad, si.min_sampl_rate, si.max_sampl_rate,
+                si.cpu_speed);
+
+        if (si.as)
+                pr_info("CPU[%i] CPUM_SF: Basic-sampling: a=%i e=%i c=%i"
+                        " bsdes=%i tear=%p dear=%p\n", cpu,
+                        si.as, si.es, si.cs, si.bsdes, si.tear, si.dear);
+        if (si.ad)
+                pr_info("CPU[%i] CPUM_SF: Diagnostic-sampling: a=%i e=%i c=%i"
+                        " dsdes=%i tear=%p dear=%p\n", cpu,
+                        si.ad, si.ed, si.cd, si.dsdes, si.tear, si.dear);
 }
 
 void perf_event_print_debug(void)
diff --git a/arch/s390/oprofile/hwsampler.c b/arch/s390/oprofile/hwsampler.c
index eb095874540d..a32c96761eab 100644
--- a/arch/s390/oprofile/hwsampler.c
+++ b/arch/s390/oprofile/hwsampler.c
@@ -799,7 +799,7 @@ static void worker_on_interrupt(unsigned int cpu)
 static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt,
                 unsigned long *dear)
 {
-        struct hws_data_entry *sample_data_ptr;
+        struct hws_basic_entry *sample_data_ptr;
         unsigned long *trailer;
 
         trailer = trailer_entry_ptr(*sdbt);
@@ -809,7 +809,7 @@ static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt,
                 trailer = dear;
         }
 
-        sample_data_ptr = (struct hws_data_entry *)(*sdbt);
+        sample_data_ptr = (struct hws_basic_entry *)(*sdbt);
 
         while ((unsigned long *)sample_data_ptr < trailer) {
                 struct pt_regs *regs = NULL;