text: /*
   * Copyright © 2013 Intel Corporation
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice (including the next
   * paragraph) shall be included in all copies or substantial portions of the
   * Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   * DEALINGS IN THE SOFTWARE.
   */
  
  /**
   * \file brw_performance_query.c
   *
   * Implementation of the GL_INTEL_performance_query extension.
   *
   * Currently there are two possible counter sources exposed here:
   *
   * On Gen6+ hardware we have numerous 64bit Pipeline Statistics Registers
   * that we can snapshot at the beginning and end of a query.
   *
   * On Gen7.5+ we have Observability Architecture counters which are
   * covered in separate document from the rest of the PRMs.  It is available at:
   * https://01.org/linuxgraphics/documentation/driver-documentation-prms
   * => 2013 Intel Core Processor Family => Observability Performance Counters
   * (This one volume covers Sandybridge, Ivybridge, Baytrail, and Haswell,
   * though notably we currently only support OA counters for Haswell+)
   */
  
  #include <limits.h>
  
  /* put before sys/types.h to silence glibc warnings */
  #ifdef MAJOR_IN_MKDEV
  #include <sys/mkdev.h>
  #endif
  #ifdef MAJOR_IN_SYSMACROS
  #include <sys/sysmacros.h>
  #endif
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <sys/mman.h>
  #include <sys/ioctl.h>
  
  #include <xf86drm.h>
  #include "drm-uapi/i915_drm.h"
  
  #include "main/hash.h"
  #include "main/macros.h"
  #include "main/mtypes.h"
  #include "main/performance_query.h"
  
  #include "util/bitset.h"
  #include "util/ralloc.h"
  #include "util/hash_table.h"
  #include "util/list.h"
  #include "util/u_math.h"
  
  #include "brw_context.h"
  #include "brw_defines.h"
  #include "brw_performance_query.h"
  #include "intel_batchbuffer.h"
  
  #include "perf/gen_perf.h"
  #include "perf/gen_perf_mdapi.h"
  
  #define FILE_DEBUG_FLAG DEBUG_PERFMON
  
  #define OAREPORT_REASON_MASK           0x3f
  #define OAREPORT_REASON_SHIFT          19
  #define OAREPORT_REASON_TIMER          (1<<0)
  #define OAREPORT_REASON_TRIGGER1       (1<<1)
  #define OAREPORT_REASON_TRIGGER2       (1<<2)
  #define OAREPORT_REASON_CTX_SWITCH     (1<<3)
  #define OAREPORT_REASON_GO_TRANSITION  (1<<4)
  
  #define I915_PERF_OA_SAMPLE_SIZE (8 +   /* drm_i915_perf_record_header */ \
                                    256)  /* OA counter report */
  
  /**
   * Periodic OA samples are read() into these buffer structures via the
   * i915 perf kernel interface and appended to the
   * brw->perfquery.sample_buffers linked list. When we process the
   * results of an OA metrics query we need to consider all the periodic
   * samples between the Begin and End MI_REPORT_PERF_COUNT command
   * markers.
   *
   * 'Periodic' is a simplification as there are other automatic reports
   * written by the hardware also buffered here.
   *
   * Considering three queries, A, B and C:
   *
   *  Time ---->
   *                ________________A_________________
   *                |                                |
   *                | ________B_________ _____C___________
   *                | |                | |           |   |
   *
   * And an illustration of sample buffers read over this time frame:
   * [HEAD ][     ][     ][     ][     ][     ][     ][     ][TAIL ]
   *
   * These nodes may hold samples for query A:
   * [     ][     ][  A  ][  A  ][  A  ][  A  ][  A  ][     ][     ]
   *
   * These nodes may hold samples for query B:
   * [     ][     ][  B  ][  B  ][  B  ][     ][     ][     ][     ]
   *
   * These nodes may hold samples for query C:
   * [     ][     ][     ][     ][     ][  C  ][  C  ][  C  ][     ]
   *
   * The illustration assumes we have an even distribution of periodic
   * samples so all nodes have the same size plotted against time:
   *
   * Note, to simplify code, the list is never empty.
   *
   * With overlapping queries we can see that periodic OA reports may
   * relate to multiple queries and care needs to be take to keep
   * track of sample buffers until there are no queries that might
   * depend on their contents.
   *
   * We use a node ref counting system where a reference ensures that a
   * node and all following nodes can't be freed/recycled until the
   * reference drops to zero.
   *
   * E.g. with a ref of one here:
   * [  0  ][  0  ][  1  ][  0  ][  0  ][  0  ][  0  ][  0  ][  0  ]
   *
   * These nodes could be freed or recycled ("reaped"):
   * [  0  ][  0  ]
   *
   * These must be preserved until the leading ref drops to zero:
   *               [  1  ][  0  ][  0  ][  0  ][  0  ][  0  ][  0  ]
   *
   * When a query starts we take a reference on the current tail of
   * the list, knowing that no already-buffered samples can possibly
   * relate to the newly-started query. A pointer to this node is
   * also saved in the query object's ->oa.samples_head.
   *
   * E.g. starting query A while there are two nodes in .sample_buffers:
   *                ________________A________
   *                |
   *
   * [  0  ][  1  ]
   *           ^_______ Add a reference and store pointer to node in
   *                    A->oa.samples_head
   *
   * Moving forward to when the B query starts with no new buffer nodes:
   * (for reference, i915 perf reads() are only done when queries finish)
   *                ________________A_______
   *                | ________B___
   *                | |
   *
   * [  0  ][  2  ]
   *           ^_______ Add a reference and store pointer to
   *                    node in B->oa.samples_head
   *
   * Once a query is finished, after an OA query has become 'Ready',
   * once the End OA report has landed and after we we have processed
   * all the intermediate periodic samples then we drop the
   * ->oa.samples_head reference we took at the start.
   *
   * So when the B query has finished we have:
   *                ________________A________
   *                | ______B___________
   *                | |                |
   * [  0  ][  1  ][  0  ][  0  ][  0  ]
   *           ^_______ Drop B->oa.samples_head reference
   *
   * We still can't free these due to the A->oa.samples_head ref:
   *        [  1  ][  0  ][  0  ][  0  ]
   *
   * When the A query finishes: (note there's a new ref for C's samples_head)
   *                ________________A_________________
   *                |                                |
   *                |                    _____C_________
   *                |                    |           |
   * [  0  ][  0  ][  0  ][  0  ][  1  ][  0  ][  0  ]
   *           ^_______ Drop A->oa.samples_head reference
   *
   * And we can now reap these nodes up to the C->oa.samples_head:
   * [  X  ][  X  ][  X  ][  X  ]
   *                  keeping -> [  1  ][  0  ][  0  ]
   *
   * We reap old sample buffers each time we finish processing an OA
   * query by iterating the sample_buffers list from the head until we
   * find a referenced node and stop.
   *
   * Reaped buffers move to a perfquery.free_sample_buffers list and
   * when we come to read() we first look to recycle a buffer from the
   * free_sample_buffers list before allocating a new buffer.
   */
  struct brw_oa_sample_buf {
     struct exec_node link;
     int refcount;
     int len;
     uint8_t buf[I915_PERF_OA_SAMPLE_SIZE * 10];
     uint32_t last_timestamp;
  };
  
  /** Downcasting convenience macro. */
  static inline struct brw_perf_query_object *
  brw_perf_query(struct gl_perf_query_object *o)
  {
     return (struct brw_perf_query_object *) o;
  }
  
  #define MI_RPC_BO_SIZE              4096
  #define MI_RPC_BO_END_OFFSET_BYTES  (MI_RPC_BO_SIZE / 2)
  #define MI_FREQ_START_OFFSET_BYTES  (3072)
  #define MI_FREQ_END_OFFSET_BYTES    (3076)
  
  /******************************************************************************/
  
  static bool
  brw_is_perf_query_ready(struct gl_context *ctx,
                          struct gl_perf_query_object *o);
  
  static uint64_t
  brw_perf_query_get_metric_id(struct brw_context *brw,
                               const struct gen_perf_query_info *query)
  {
     /* These queries are know not to ever change, their config ID has been
      * loaded upon the first query creation. No need to look them up again.
      */
     if (query->kind == GEN_PERF_QUERY_TYPE_OA)
        return query->oa_metrics_set_id;
  
     assert(query->kind == GEN_PERF_QUERY_TYPE_RAW);
  
     /* Raw queries can be reprogrammed up by an external application/library.
      * When a raw query is used for the first time it's id is set to a value !=
      * 0. When it stops being used the id returns to 0. No need to reload the
      * ID when it's already loaded.
      */
     if (query->oa_metrics_set_id != 0) {
        DBG("Raw query '%s' guid=%s using cached ID: %"PRIu64"\n",
            query->name, query->guid, query->oa_metrics_set_id);
        return query->oa_metrics_set_id;
     }
  
     struct gen_perf_query_info *raw_query = (struct gen_perf_query_info *)query;
     if (!gen_perf_load_metric_id(brw->perfquery.perf, query->guid,
                                  &raw_query->oa_metrics_set_id)) {
        DBG("Unable to read query guid=%s ID, falling back to test config\n", query->guid);
        raw_query->oa_metrics_set_id = 1ULL;
     } else {
        DBG("Raw query '%s'guid=%s loaded ID: %"PRIu64"\n",
            query->name, query->guid, query->oa_metrics_set_id);
     }
     return query->oa_metrics_set_id;
  }
  
  static void
  dump_perf_query_callback(GLuint id, void *query_void, void *brw_void)
  {
     struct gl_context *ctx = brw_void;
     struct gl_perf_query_object *o = query_void;
     struct brw_perf_query_object *obj = query_void;
  
     switch (obj->query->kind) {
     case GEN_PERF_QUERY_TYPE_OA:
     case GEN_PERF_QUERY_TYPE_RAW:
        DBG("%4d: %-6s %-8s BO: %-4s OA data: %-10s %-15s\n",
            id,
            o->Used ? "Dirty," : "New,",
            o->Active ? "Active," : (o->Ready ? "Ready," : "Pending,"),
            obj->oa.bo ? "yes," : "no,",
            brw_is_perf_query_ready(ctx, o) ? "ready," : "not ready,",
            obj->oa.results_accumulated ? "accumulated" : "not accumulated");
        break;
     case GEN_PERF_QUERY_TYPE_PIPELINE:
        DBG("%4d: %-6s %-8s BO: %-4s\n",
            id,
            o->Used ? "Dirty," : "New,",
            o->Active ? "Active," : (o->Ready ? "Ready," : "Pending,"),
            obj->pipeline_stats.bo ? "yes" : "no");
        break;
     default:
        unreachable("Unknown query type");
        break;
     }
  }
  
  static void
  dump_perf_queries(struct brw_context *brw)
  {
     struct gl_context *ctx = &brw->ctx;
     DBG("Queries: (Open queries = %d, OA users = %d)\n",
         brw->perfquery.n_active_oa_queries, brw->perfquery.n_oa_users);
     _mesa_HashWalk(ctx->PerfQuery.Objects, dump_perf_query_callback, brw);
  }
  
  /******************************************************************************/
  
  static struct brw_oa_sample_buf *
  get_free_sample_buf(struct brw_context *brw)
  {
     struct exec_node *node = exec_list_pop_head(&brw->perfquery.free_sample_buffers);
     struct brw_oa_sample_buf *buf;
  
     if (node)
        buf = exec_node_data(struct brw_oa_sample_buf, node, link);
     else {
        buf = ralloc_size(brw, sizeof(*buf));
  
        exec_node_init(&buf->link);
        buf->refcount = 0;
        buf->len = 0;
     }
  
     return buf;
  }
  
  static void
  reap_old_sample_buffers(struct brw_context *brw)
  {
     struct exec_node *tail_node =
        exec_list_get_tail(&brw->perfquery.sample_buffers);
     struct brw_oa_sample_buf *tail_buf =
        exec_node_data(struct brw_oa_sample_buf, tail_node, link);
  
     /* Remove all old, unreferenced sample buffers walking forward from
      * the head of the list, except always leave at least one node in
      * the list so we always have a node to reference when we Begin
      * a new query.
      */
     foreach_list_typed_safe(struct brw_oa_sample_buf, buf, link,
                             &brw->perfquery.sample_buffers)
     {
        if (buf->refcount == 0 && buf != tail_buf) {
           exec_node_remove(&buf->link);
           exec_list_push_head(&brw->perfquery.free_sample_buffers, &buf->link);
        } else
           return;
     }
  }
  
  static void
  free_sample_bufs(struct brw_context *brw)
  {
     foreach_list_typed_safe(struct brw_oa_sample_buf, buf, link,
                             &brw->perfquery.free_sample_buffers)
        ralloc_free(buf);
  
     exec_list_make_empty(&brw->perfquery.free_sample_buffers);
  }
  
  /******************************************************************************/
  
  /**
   * Driver hook for glGetPerfQueryInfoINTEL().
   */
  static void
  brw_get_perf_query_info(struct gl_context *ctx,
                          unsigned query_index,
                          const char **name,
                          GLuint *data_size,
                          GLuint *n_counters,
                          GLuint *n_active)
  {
     struct brw_context *brw = brw_context(ctx);
     const struct gen_perf_query_info *query =
        &brw->perfquery.perf->queries[query_index];
  
     *name = query->name;
     *data_size = query->data_size;
     *n_counters = query->n_counters;
  
     switch (query->kind) {
     case GEN_PERF_QUERY_TYPE_OA:
     case GEN_PERF_QUERY_TYPE_RAW:
        *n_active = brw->perfquery.n_active_oa_queries;
        break;
  
     case GEN_PERF_QUERY_TYPE_PIPELINE:
        *n_active = brw->perfquery.n_active_pipeline_stats_queries;
        break;
  
     default:
        unreachable("Unknown query type");
        break;
     }
  }
  
  static GLuint
  gen_counter_type_enum_to_gl_type(enum gen_perf_counter_type type)
  {
     switch (type) {
     case GEN_PERF_COUNTER_TYPE_EVENT: return GL_PERFQUERY_COUNTER_EVENT_INTEL;
     case GEN_PERF_COUNTER_TYPE_DURATION_NORM: return GL_PERFQUERY_COUNTER_DURATION_NORM_INTEL;
     case GEN_PERF_COUNTER_TYPE_DURATION_RAW: return GL_PERFQUERY_COUNTER_DURATION_RAW_INTEL;
     case GEN_PERF_COUNTER_TYPE_THROUGHPUT: return GL_PERFQUERY_COUNTER_THROUGHPUT_INTEL;
     case GEN_PERF_COUNTER_TYPE_RAW: return GL_PERFQUERY_COUNTER_RAW_INTEL;
     case GEN_PERF_COUNTER_TYPE_TIMESTAMP: return GL_PERFQUERY_COUNTER_TIMESTAMP_INTEL;
     default:
        unreachable("Unknown counter type");
     }
  }
  
  static GLuint
  gen_counter_data_type_to_gl_type(enum gen_perf_counter_data_type type)
  {
     switch (type) {
     case GEN_PERF_COUNTER_DATA_TYPE_BOOL32: return GL_PERFQUERY_COUNTER_DATA_BOOL32_INTEL;
     case GEN_PERF_COUNTER_DATA_TYPE_UINT32: return GL_PERFQUERY_COUNTER_DATA_UINT32_INTEL;
     case GEN_PERF_COUNTER_DATA_TYPE_UINT64: return GL_PERFQUERY_COUNTER_DATA_UINT64_INTEL;
     case GEN_PERF_COUNTER_DATA_TYPE_FLOAT: return GL_PERFQUERY_COUNTER_DATA_FLOAT_INTEL;
     case GEN_PERF_COUNTER_DATA_TYPE_DOUBLE: return GL_PERFQUERY_COUNTER_DATA_DOUBLE_INTEL;
     default:
        unreachable("Unknown counter data type");
     }
  }
  
  /**
   * Driver hook for glGetPerfCounterInfoINTEL().
   */
  static void
  brw_get_perf_counter_info(struct gl_context *ctx,
                            unsigned query_index,
                            unsigned counter_index,
                            const char **name,
                            const char **desc,
                            GLuint *offset,
                            GLuint *data_size,
                            GLuint *type_enum,
                            GLuint *data_type_enum,
                            GLuint64 *raw_max)
  {
     struct brw_context *brw = brw_context(ctx);
     const struct gen_perf_query_info *query =
        &brw->perfquery.perf->queries[query_index];
     const struct gen_perf_query_counter *counter =
        &query->counters[counter_index];
  
     *name = counter->name;
     *desc = counter->desc;
     *offset = counter->offset;
     *data_size = gen_perf_query_counter_get_size(counter);
     *type_enum = gen_counter_type_enum_to_gl_type(counter->type);
     *data_type_enum = gen_counter_data_type_to_gl_type(counter->data_type);
     *raw_max = counter->raw_max;
  }
  
  /******************************************************************************/
  
  /**
   * Emit MI_STORE_REGISTER_MEM commands to capture all of the
   * pipeline statistics for the performance query object.
   */
  static void
  snapshot_statistics_registers(struct brw_context *brw,
                                struct brw_perf_query_object *obj,
                                uint32_t offset_in_bytes)
  {
     const struct gen_perf_query_info *query = obj->query;
     const int n_counters = query->n_counters;
  
     for (int i = 0; i < n_counters; i++) {
        const struct gen_perf_query_counter *counter = &query->counters[i];
  
        assert(counter->data_type == GEN_PERF_COUNTER_DATA_TYPE_UINT64);
  
        brw_store_register_mem64(brw, obj->pipeline_stats.bo,
                                 counter->pipeline_stat.reg,
                                 offset_in_bytes + i * sizeof(uint64_t));
     }
  }
  
  /**
   * Add a query to the global list of "unaccumulated queries."
   *
   * Queries are tracked here until all the associated OA reports have
   * been accumulated via accumulate_oa_reports() after the end
   * MI_REPORT_PERF_COUNT has landed in query->oa.bo.
   */
  static void
  add_to_unaccumulated_query_list(struct brw_context *brw,
                                  struct brw_perf_query_object *obj)
  {
     if (brw->perfquery.unaccumulated_elements >=
         brw->perfquery.unaccumulated_array_size)
     {
        brw->perfquery.unaccumulated_array_size *= 1.5;
        brw->perfquery.unaccumulated =
           reralloc(brw, brw->perfquery.unaccumulated,
                    struct brw_perf_query_object *,
                    brw->perfquery.unaccumulated_array_size);
     }
  
     brw->perfquery.unaccumulated[brw->perfquery.unaccumulated_elements++] = obj;
  }
  
  /**
   * Remove a query from the global list of unaccumulated queries once
   * after successfully accumulating the OA reports associated with the
   * query in accumulate_oa_reports() or when discarding unwanted query
   * results.
   */
  static void
  drop_from_unaccumulated_query_list(struct brw_context *brw,
                                     struct brw_perf_query_object *obj)
  {
     for (int i = 0; i < brw->perfquery.unaccumulated_elements; i++) {
        if (brw->perfquery.unaccumulated[i] == obj) {
           int last_elt = --brw->perfquery.unaccumulated_elements;
  
           if (i == last_elt)
              brw->perfquery.unaccumulated[i] = NULL;
           else {
              brw->perfquery.unaccumulated[i] =
                 brw->perfquery.unaccumulated[last_elt];
           }
  
           break;
        }
     }
  
     /* Drop our samples_head reference so that associated periodic
      * sample data buffers can potentially be reaped if they aren't
      * referenced by any other queries...
      */
  
     struct brw_oa_sample_buf *buf =
        exec_node_data(struct brw_oa_sample_buf, obj->oa.samples_head, link);
  
     assert(buf->refcount > 0);
     buf->refcount--;
  
     obj->oa.samples_head = NULL;
  
     reap_old_sample_buffers(brw);
  }
  
  static bool
  inc_n_oa_users(struct brw_context *brw)
  {
     if (brw->perfquery.n_oa_users == 0 &&
         drmIoctl(brw->perfquery.oa_stream_fd,
                  I915_PERF_IOCTL_ENABLE, 0) < 0)
     {
        return false;
     }
     ++brw->perfquery.n_oa_users;
  
     return true;
  }
  
  static void
  dec_n_oa_users(struct brw_context *brw)
  {
     /* Disabling the i915 perf stream will effectively disable the OA
      * counters.  Note it's important to be sure there are no outstanding
      * MI_RPC commands at this point since they could stall the CS
      * indefinitely once OACONTROL is disabled.
      */
     --brw->perfquery.n_oa_users;
     if (brw->perfquery.n_oa_users == 0 &&
         drmIoctl(brw->perfquery.oa_stream_fd, I915_PERF_IOCTL_DISABLE, 0) < 0)
     {
        DBG("WARNING: Error disabling i915 perf stream: %m\n");
     }
  }
  
  /* In general if we see anything spurious while accumulating results,
   * we don't try and continue accumulating the current query, hoping
   * for the best, we scrap anything outstanding, and then hope for the
   * best with new queries.
   */
  static void
  discard_all_queries(struct brw_context *brw)
  {
     while (brw->perfquery.unaccumulated_elements) {
        struct brw_perf_query_object *obj = brw->perfquery.unaccumulated[0];
  
        obj->oa.results_accumulated = true;
        drop_from_unaccumulated_query_list(brw, brw->perfquery.unaccumulated[0]);
  
        dec_n_oa_users(brw);
     }
  }
  
  enum OaReadStatus {
     OA_READ_STATUS_ERROR,
     OA_READ_STATUS_UNFINISHED,
     OA_READ_STATUS_FINISHED,
  };
  
  static enum OaReadStatus
  read_oa_samples_until(struct brw_context *brw,
                        uint32_t start_timestamp,
                        uint32_t end_timestamp)
  {
     struct exec_node *tail_node =
        exec_list_get_tail(&brw->perfquery.sample_buffers);
     struct brw_oa_sample_buf *tail_buf =
        exec_node_data(struct brw_oa_sample_buf, tail_node, link);
     uint32_t last_timestamp = tail_buf->last_timestamp;
  
     while (1) {
        struct brw_oa_sample_buf *buf = get_free_sample_buf(brw);
        uint32_t offset;
        int len;
  
        while ((len = read(brw->perfquery.oa_stream_fd, buf->buf,
                           sizeof(buf->buf))) < 0 && errno == EINTR)
           ;
  
        if (len <= 0) {
           exec_list_push_tail(&brw->perfquery.free_sample_buffers, &buf->link);
  
           if (len < 0) {
              if (errno == EAGAIN)
                 return ((last_timestamp - start_timestamp) >=
                         (end_timestamp - start_timestamp)) ?
                        OA_READ_STATUS_FINISHED :
                        OA_READ_STATUS_UNFINISHED;
              else {
                 DBG("Error reading i915 perf samples: %m\n");
              }
           } else
              DBG("Spurious EOF reading i915 perf samples\n");
  
           return OA_READ_STATUS_ERROR;
        }
  
        buf->len = len;
        exec_list_push_tail(&brw->perfquery.sample_buffers, &buf->link);
  
        /* Go through the reports and update the last timestamp. */
        offset = 0;
        while (offset < buf->len) {
           const struct drm_i915_perf_record_header *header =
              (const struct drm_i915_perf_record_header *) &buf->buf[offset];
           uint32_t *report = (uint32_t *) (header + 1);
  
           if (header->type == DRM_I915_PERF_RECORD_SAMPLE)
              last_timestamp = report[1];
  
           offset += header->size;
        }
  
        buf->last_timestamp = last_timestamp;
     }
  
     unreachable("not reached");
     return OA_READ_STATUS_ERROR;
  }
  
  /**
   * Try to read all the reports until either the delimiting timestamp
   * or an error arises.
   */
  static bool
  read_oa_samples_for_query(struct brw_context *brw,
                            struct brw_perf_query_object *obj)
  {
     uint32_t *start;
     uint32_t *last;
     uint32_t *end;
  
     /* We need the MI_REPORT_PERF_COUNT to land before we can start
      * accumulate. */
     assert(!brw_batch_references(&brw->batch, obj->oa.bo) &&
            !brw_bo_busy(obj->oa.bo));
  
     /* Map the BO once here and let accumulate_oa_reports() unmap
      * it. */
     if (obj->oa.map == NULL)
        obj->oa.map = brw_bo_map(brw, obj->oa.bo, MAP_READ);
  
     start = last = obj->oa.map;
     end = obj->oa.map + MI_RPC_BO_END_OFFSET_BYTES;
  
     if (start[0] != obj->oa.begin_report_id) {
        DBG("Spurious start report id=%"PRIu32"\n", start[0]);
        return true;
     }
     if (end[0] != (obj->oa.begin_report_id + 1)) {
        DBG("Spurious end report id=%"PRIu32"\n", end[0]);
        return true;
     }
  
     /* Read the reports until the end timestamp. */
     switch (read_oa_samples_until(brw, start[1], end[1])) {
     case OA_READ_STATUS_ERROR:
        /* Fallthrough and let accumulate_oa_reports() deal with the
         * error. */
     case OA_READ_STATUS_FINISHED:
        return true;
     case OA_READ_STATUS_UNFINISHED:
        return false;
     }
  
     unreachable("invalid read status");
     return false;
  }
  
  /**
   * Accumulate raw OA counter values based on deltas between pairs of
   * OA reports.
   *
   * Accumulation starts from the first report captured via
   * MI_REPORT_PERF_COUNT (MI_RPC) by brw_begin_perf_query() until the
   * last MI_RPC report requested by brw_end_perf_query(). Between these
   * two reports there may also some number of periodically sampled OA
   * reports collected via the i915 perf interface - depending on the
   * duration of the query.
   *
   * These periodic snapshots help to ensure we handle counter overflow
   * correctly by being frequent enough to ensure we don't miss multiple
   * overflows of a counter between snapshots. For Gen8+ the i915 perf
   * snapshots provide the extra context-switch reports that let us
   * subtract out the progress of counters associated with other
   * contexts running on the system.
   */
  static void
  accumulate_oa_reports(struct brw_context *brw,
                        struct brw_perf_query_object *obj)
  {
     const struct gen_device_info *devinfo = &brw->screen->devinfo;
     struct gl_perf_query_object *o = &obj->base;
     uint32_t *start;
     uint32_t *last;
     uint32_t *end;
     struct exec_node *first_samples_node;
     bool in_ctx = true;
     int out_duration = 0;
  
     assert(o->Ready);
     assert(obj->oa.map != NULL);
  
     start = last = obj->oa.map;
     end = obj->oa.map + MI_RPC_BO_END_OFFSET_BYTES;
  
     if (start[0] != obj->oa.begin_report_id) {
        DBG("Spurious start report id=%"PRIu32"\n", start[0]);
        goto error;
     }
     if (end[0] != (obj->oa.begin_report_id + 1)) {
        DBG("Spurious end report id=%"PRIu32"\n", end[0]);
        goto error;
     }
  
     /* See if we have any periodic reports to accumulate too... */
  
     /* N.B. The oa.samples_head was set when the query began and
      * pointed to the tail of the brw->perfquery.sample_buffers list at
      * the time the query started. Since the buffer existed before the
      * first MI_REPORT_PERF_COUNT command was emitted we therefore know
      * that no data in this particular node's buffer can possibly be
      * associated with the query - so skip ahead one...
      */
     first_samples_node = obj->oa.samples_head->next;
  
     foreach_list_typed_from(struct brw_oa_sample_buf, buf, link,
                             &brw->perfquery.sample_buffers,
                             first_samples_node)
     {
        int offset = 0;
  
        while (offset < buf->len) {
           const struct drm_i915_perf_record_header *header =
              (const struct drm_i915_perf_record_header *)(buf->buf + offset);
  
           assert(header->size != 0);
           assert(header->size <= buf->len);
  
           offset += header->size;
  
           switch (header->type) {
           case DRM_I915_PERF_RECORD_SAMPLE: {
              uint32_t *report = (uint32_t *)(header + 1);
              bool add = true;
  
              /* Ignore reports that come before the start marker.
               * (Note: takes care to allow overflow of 32bit timestamps)
               */
              if (gen_device_info_timebase_scale(devinfo,
                                                 report[1] - start[1]) > 5000000000) {
                 continue;
              }
  
              /* Ignore reports that come after the end marker.
               * (Note: takes care to allow overflow of 32bit timestamps)
               */
              if (gen_device_info_timebase_scale(devinfo,
                                                 report[1] - end[1]) <= 5000000000) {
                 goto end;
              }
  
              /* For Gen8+ since the counters continue while other
               * contexts are running we need to discount any unrelated
               * deltas. The hardware automatically generates a report
               * on context switch which gives us a new reference point
               * to continuing adding deltas from.
               *
               * For Haswell we can rely on the HW to stop the progress
               * of OA counters while any other context is acctive.
               */
              if (devinfo->gen >= 8) {
                 if (in_ctx && report[2] != obj->oa.result.hw_id) {
                    DBG("i915 perf: Switch AWAY (observed by ID change)\n");
                    in_ctx = false;
                    out_duration = 0;
                 } else if (in_ctx == false && report[2] == obj->oa.result.hw_id) {
                    DBG("i915 perf: Switch TO\n");
                    in_ctx = true;
  
                    /* From experimentation in IGT, we found that the OA unit
                     * might label some report as "idle" (using an invalid
                     * context ID), right after a report for a given context.
                     * Deltas generated by those reports actually belong to the
                     * previous context, even though they're not labelled as
                     * such.
                     *
                     * We didn't *really* Switch AWAY in the case that we e.g.
                     * saw a single periodic report while idle...
                     */
                    if (out_duration >= 1)
                       add = false;
                 } else if (in_ctx) {
                    assert(report[2] == obj->oa.result.hw_id);
                    DBG("i915 perf: Continuation IN\n");
                 } else {
                    assert(report[2] != obj->oa.result.hw_id);
                    DBG("i915 perf: Continuation OUT\n");
                    add = false;
                    out_duration++;
                 }
              }
  
              if (add) {
                 gen_perf_query_result_accumulate(&obj->oa.result, obj->query,
                                                  last, report);
              }
  
              last = report;
  
              break;
           }
  
           case DRM_I915_PERF_RECORD_OA_BUFFER_LOST:
               DBG("i915 perf: OA error: all reports lost\n");
               goto error;
           case DRM_I915_PERF_RECORD_OA_REPORT_LOST:
               DBG("i915 perf: OA report lost\n");
               break;
           }
        }
     }
  
  end:
  
     gen_perf_query_result_accumulate(&obj->oa.result, obj->query,
                                      last, end);
  
     DBG("Marking %d accumulated - results gathered\n", o->Id);
  
     obj->oa.results_accumulated = true;
     drop_from_unaccumulated_query_list(brw, obj);
     dec_n_oa_users(brw);
  
     return;
  
  error:
  
     discard_all_queries(brw);
  }
  
  /******************************************************************************/
  
  static bool
  open_i915_perf_oa_stream(struct brw_context *brw,
                           int metrics_set_id,
                           int report_format,
                           int period_exponent,
                           int drm_fd,
                           uint32_t ctx_id)
  {
     uint64_t properties[] = {
        /* Single context sampling */
        DRM_I915_PERF_PROP_CTX_HANDLE, ctx_id,
  
        /* Include OA reports in samples */
        DRM_I915_PERF_PROP_SAMPLE_OA, true,
  
        /* OA unit configuration */
        DRM_I915_PERF_PROP_OA_METRICS_SET, metrics_set_id,
        DRM_I915_PERF_PROP_OA_FORMAT, report_format,
        DRM_I915_PERF_PROP_OA_EXPONENT, period_exponent,
     };
     struct drm_i915_perf_open_param param = {
        .flags = I915_PERF_FLAG_FD_CLOEXEC |
                 I915_PERF_FLAG_FD_NONBLOCK |
                 I915_PERF_FLAG_DISABLED,
        .num_properties = ARRAY_SIZE(properties) / 2,
        .properties_ptr = (uintptr_t) properties,
     };
     int fd = drmIoctl(drm_fd, DRM_IOCTL_I915_PERF_OPEN, &param);
     if (fd == -1) {
        DBG("Error opening i915 perf OA stream: %m\n");
        return false;
     }
  
     brw->perfquery.oa_stream_fd = fd;
  
     brw->perfquery.current_oa_metrics_set_id = metrics_set_id;
     brw->perfquery.current_oa_format = report_format;
  
     return true;
  }
  
  static void
  close_perf(struct brw_context *brw,
             const struct gen_perf_query_info *query)
  {
     if (brw->perfquery.oa_stream_fd != -1) {
        close(brw->perfquery.oa_stream_fd);
        brw->perfquery.oa_stream_fd = -1;
     }
     if (query->kind == GEN_PERF_QUERY_TYPE_RAW) {
        struct gen_perf_query_info *raw_query =
           (struct gen_perf_query_info *) query;
        raw_query->oa_metrics_set_id = 0;
     }
  }
  
  static void
  capture_frequency_stat_register(struct brw_context *brw,
                                  struct brw_bo *bo,
                                  uint32_t bo_offset)
  {
     const struct gen_device_info *devinfo = &brw->screen->devinfo;
  
     if (devinfo->gen >= 7 && devinfo->gen <= 8 &&
         !devinfo->is_baytrail && !devinfo->is_cherryview) {
        brw_store_register_mem32(brw, bo, GEN7_RPSTAT1, bo_offset);
     } else if (devinfo->gen >= 9) {
        brw_store_register_mem32(brw, bo, GEN9_RPSTAT0, bo_offset);
     }
  }
  
  /**
   * Driver hook for glBeginPerfQueryINTEL().
   */
  static bool
  brw_begin_perf_query(struct gl_context *ctx,
                       struct gl_perf_query_object *o)
  {
     struct brw_context *brw = brw_context(ctx);
     struct brw_perf_query_object *obj = brw_perf_query(o);
     const struct gen_perf_query_info *query = obj->query;
  
     /* We can assume the frontend hides mistaken attempts to Begin a
      * query object multiple times before its End. Similarly if an
      * application reuses a query object before results have arrived
      * the frontend will wait for prior results so we don't need
      * to support abandoning in-flight results.
      */
     assert(!o->Active);
     assert(!o->Used || o->Ready); /* no in-flight query to worry about */
  
     DBG("Begin(%d)\n", o->Id);
  
     /* XXX: We have to consider that the command parser unit that parses batch
      * buffer commands and is used to capture begin/end counter snapshots isn't
      * implicitly synchronized with what's currently running across other GPU
      * units (such as the EUs running shaders) that the performance counters are
      * associated with.
      *
      * The intention of performance queries is to measure the work associated
      * with commands between the begin/end delimiters and so for that to be the
      * case we need to explicitly synchronize the parsing of commands to capture
      * Begin/End counter snapshots with what's running across other parts of the
      * GPU.
      *
      * When the command parser reaches a Begin marker it effectively needs to
      * drain everything currently running on the GPU until the hardware is idle
      * before capturing the first snapshot of counters - otherwise the results
      * would also be measuring the effects of earlier commands.
      *
      * When the command parser reaches an End marker it needs to stall until
      * everything currently running on the GPU has finished before capturing the
      * end snapshot - otherwise the results won't be a complete representation
      * of the work.
      *
      * Theoretically there could be opportunities to minimize how much of the
      * GPU pipeline is drained, or that we stall for, when we know what specific
      * units the performance counters being queried relate to but we don't
      * currently attempt to be clever here.
      *
      * Note: with our current simple approach here then for back-to-back queries
      * we will redundantly emit duplicate commands to synchronize the command
      * streamer with the rest of the GPU pipeline, but we assume that in HW the
      * second synchronization is effectively a NOOP.
      *
      * N.B. The final results are based on deltas of counters between (inside)
      * Begin/End markers so even though the total wall clock time of the
      * workload is stretched by larger pipeline bubbles the bubbles themselves
      * are generally invisible to the query results. Whether that's a good or a
      * bad thing depends on the use case. For a lower real-time impact while
      * capturing metrics then periodic sampling may be a better choice than
      * INTEL_performance_query.
      *
      *
      * This is our Begin synchronization point to drain current work on the
      * GPU before we capture our first counter snapshot...
      */
     brw_emit_mi_flush(brw);
  
     switch (query->kind) {
     case GEN_PERF_QUERY_TYPE_OA:
     case GEN_PERF_QUERY_TYPE_RAW: {
  
        /* Opening an i915 perf stream implies exclusive access to the OA unit
         * which will generate counter reports for a specific counter set with a
         * specific layout/format so we can't begin any OA based queries that
         * require a different counter set or format unless we get an opportunity
         * to close the stream and open a new one...
         */
        uint64_t metric_id = brw_perf_query_get_metric_id(brw, query);
  
        if (brw->perfquery.oa_stream_fd != -1 &&
            brw->perfquery.current_oa_metrics_set_id != metric_id) {
  
           if (brw->perfquery.n_oa_users != 0) {
              DBG("WARNING: Begin(%d) failed already using perf config=%i/%"PRIu64"\n",
                  o->Id, brw->perfquery.current_oa_metrics_set_id, metric_id);
              return false;
           } else
              close_perf(brw, query);
        }
  
        /* If the OA counters aren't already on, enable them. */
        if (brw->perfquery.oa_stream_fd == -1) {
           __DRIscreen *screen = brw->screen->driScrnPriv;
           const struct gen_device_info *devinfo = &brw->screen->devinfo;
  
           /* The period_exponent gives a sampling period as follows:
            *   sample_period = timestamp_period * 2^(period_exponent + 1)
            *
            * The timestamps increments every 80ns (HSW), ~52ns (GEN9LP) or
            * ~83ns (GEN8/9).
            *
            * The counter overflow period is derived from the EuActive counter
            * which reads a counter that increments by the number of clock
            * cycles multiplied by the number of EUs. It can be calculated as:
            *
            * 2^(number of bits in A counter) / (n_eus * max_gen_freq * 2)
            *
            * (E.g. 40 EUs @ 1GHz = ~53ms)
            *
            * We select a sampling period inferior to that overflow period to
            * ensure we cannot see more than 1 counter overflow, otherwise we
            * could loose information.
            */
  
           int a_counter_in_bits = 32;
           if (devinfo->gen >= 8)
              a_counter_in_bits = 40;
  
           uint64_t overflow_period = pow(2, a_counter_in_bits) /
              (brw->perfquery.perf->sys_vars.n_eus *
               /* drop 1GHz freq to have units in nanoseconds */
               2);
  
           DBG("A counter overflow period: %"PRIu64"ns, %"PRIu64"ms (n_eus=%"PRIu64")\n",
               overflow_period, overflow_period / 1000000ul, brw->perfquery.perf->sys_vars.n_eus);
  
           int period_exponent = 0;
           uint64_t prev_sample_period, next_sample_period;
           for (int e = 0; e < 30; e++) {
              prev_sample_period = 1000000000ull * pow(2, e + 1) / devinfo->timestamp_frequency;
              next_sample_period = 1000000000ull * pow(2, e + 2) / devinfo->timestamp_frequency;
  
              /* Take the previous sampling period, lower than the overflow
               * period.
               */
              if (prev_sample_period < overflow_period &&
                  next_sample_period > overflow_period)
                 period_exponent = e + 1;
           }
  
           if (period_exponent == 0) {
              DBG("WARNING: enable to find a sampling exponent\n");
              return false;
           }
  
           DBG("OA sampling exponent: %i ~= %"PRIu64"ms\n", period_exponent,
               prev_sample_period / 1000000ul);
  
           if (!open_i915_perf_oa_stream(brw,
                                         metric_id,
                                         query->oa_format,
                                         period_exponent,
                                         screen->fd, /* drm fd */
                                         brw->hw_ctx))
              return false;
        } else {
           assert(brw->perfquery.current_oa_metrics_set_id == metric_id &&
                  brw->perfquery.current_oa_format == query->oa_format);
        }
  
        if (!inc_n_oa_users(brw)) {
           DBG("WARNING: Error enabling i915 perf stream: %m\n");
           return false;
        }
  
        if (obj->oa.bo) {
           brw_bo_unreference(obj->oa.bo);
           obj->oa.bo = NULL;
        }
  
        obj->oa.bo =
           brw_bo_alloc(brw->bufmgr, "perf. query OA MI_RPC bo", MI_RPC_BO_SIZE,
                        BRW_MEMZONE_OTHER);
  #ifdef DEBUG
        /* Pre-filling the BO helps debug whether writes landed. */
        void *map = brw_bo_map(brw, obj->oa.bo, MAP_WRITE);
        memset(map, 0x80, MI_RPC_BO_SIZE);
        brw_bo_unmap(obj->oa.bo);
  #endif
  
        obj->oa.begin_report_id = brw->perfquery.next_query_start_report_id;
        brw->perfquery.next_query_start_report_id += 2;
  
        /* We flush the batchbuffer here to minimize the chances that MI_RPC
         * delimiting commands end up in different batchbuffers. If that's the
         * case, the measurement will include the time it takes for the kernel
         * scheduler to load a new request into the hardware. This is manifested in
         * tools like frameretrace by spikes in the "GPU Core Clocks" counter.
         */
        intel_batchbuffer_flush(brw);
  
        /* Take a starting OA counter snapshot. */
        brw->vtbl.emit_mi_report_perf_count(brw, obj->oa.bo, 0,
                                            obj->oa.begin_report_id);
        capture_frequency_stat_register(brw, obj->oa.bo, MI_FREQ_START_OFFSET_BYTES);
  
        ++brw->perfquery.n_active_oa_queries;
  
        /* No already-buffered samples can possibly be associated with this query
         * so create a marker within the list of sample buffers enabling us to
         * easily ignore earlier samples when processing this query after
         * completion.
         */
        assert(!exec_list_is_empty(&brw->perfquery.sample_buffers));
        obj->oa.samples_head = exec_list_get_tail(&brw->perfquery.sample_buffers);
  
        struct brw_oa_sample_buf *buf =
           exec_node_data(struct brw_oa_sample_buf, obj->oa.samples_head, link);
  
        /* This reference will ensure that future/following sample
         * buffers (that may relate to this query) can't be freed until
         * this drops to zero.
         */
        buf->refcount++;
  
        gen_perf_query_result_clear(&obj->oa.result);
        obj->oa.results_accumulated = false;
  
        add_to_unaccumulated_query_list(brw, obj);
        break;
     }
  
     case GEN_PERF_QUERY_TYPE_PIPELINE:
        if (obj->pipeline_stats.bo) {
           brw_bo_unreference(obj->pipeline_stats.bo);
           obj->pipeline_stats.bo = NULL;
        }
  
        obj->pipeline_stats.bo =
           brw_bo_alloc(brw->bufmgr, "perf. query pipeline stats bo",
                        STATS_BO_SIZE, BRW_MEMZONE_OTHER);
  
        /* Take starting snapshots. */
        snapshot_statistics_registers(brw, obj, 0);
  
        ++brw->perfquery.n_active_pipeline_stats_queries;
        break;
  
     default:
        unreachable("Unknown query type");
        break;
     }
  
     if (INTEL_DEBUG & DEBUG_PERFMON)
        dump_perf_queries(brw);
  
     return true;
  }
  
  /**
   * Driver hook for glEndPerfQueryINTEL().
   */
  static void
  brw_end_perf_query(struct gl_context *ctx,
                       struct gl_perf_query_object *o)
  {
     struct brw_context *brw = brw_context(ctx);
     struct brw_perf_query_object *obj = brw_perf_query(o);
  
     DBG("End(%d)\n", o->Id);
  
     /* Ensure that the work associated with the queried commands will have
      * finished before taking our query end counter readings.
      *
      * For more details see comment in brw_begin_perf_query for
      * corresponding flush.
      */
     brw_emit_mi_flush(brw);
  
     switch (obj->query->kind) {
     case GEN_PERF_QUERY_TYPE_OA:
     case GEN_PERF_QUERY_TYPE_RAW:
  
        /* NB: It's possible that the query will have already been marked
         * as 'accumulated' if an error was seen while reading samples
         * from perf. In this case we mustn't try and emit a closing
         * MI_RPC command in case the OA unit has already been disabled
         */
        if (!obj->oa.results_accumulated) {
           /* Take an ending OA counter snapshot. */
           capture_frequency_stat_register(brw, obj->oa.bo, MI_FREQ_END_OFFSET_BYTES);
           brw->vtbl.emit_mi_report_perf_count(brw, obj->oa.bo,
                                               MI_RPC_BO_END_OFFSET_BYTES,
                                               obj->oa.begin_report_id + 1);
        }
  
        --brw->perfquery.n_active_oa_queries;
  
        /* NB: even though the query has now ended, it can't be accumulated
         * until the end MI_REPORT_PERF_COUNT snapshot has been written
         * to query->oa.bo
         */
        break;
  
     case GEN_PERF_QUERY_TYPE_PIPELINE:
        snapshot_statistics_registers(brw, obj,
                                      STATS_BO_END_OFFSET_BYTES);
        --brw->perfquery.n_active_pipeline_stats_queries;
        break;
  
     default:
        unreachable("Unknown query type");
        break;
     }
  }
  
  static void
  brw_wait_perf_query(struct gl_context *ctx, struct gl_perf_query_object *o)
  {
     struct brw_context *brw = brw_context(ctx);
     struct brw_perf_query_object *obj = brw_perf_query(o);
     struct brw_bo *bo = NULL;
  
     assert(!o->Ready);
  
     switch (obj->query->kind) {
     case GEN_PERF_QUERY_TYPE_OA:
     case GEN_PERF_QUERY_TYPE_RAW:
        bo = obj->oa.bo;
        break;
  
     case GEN_PERF_QUERY_TYPE_PIPELINE:
        bo = obj->pipeline_stats.bo;
        break;
  
     default:
        unreachable("Unknown query type");
        break;
     }
  
     if (bo == NULL)
        return;
  
     /* If the current batch references our results bo then we need to
      * flush first...
      */
     if (brw_batch_references(&brw->batch, bo))
        intel_batchbuffer_flush(brw);
  
     brw_bo_wait_rendering(bo);
  
     /* Due to a race condition between the OA unit signaling report
      * availability and the report actually being written into memory,
      * we need to wait for all the reports to come in before we can
      * read them.
      */
     if (obj->query->kind == GEN_PERF_QUERY_TYPE_OA ||
         obj->query->kind == GEN_PERF_QUERY_TYPE_RAW) {
        while (!read_oa_samples_for_query(brw, obj))
           ;
     }
  }
  
  static bool
  brw_is_perf_query_ready(struct gl_context *ctx,
                          struct gl_perf_query_object *o)
  {
     struct brw_context *brw = brw_context(ctx);
     struct brw_perf_query_object *obj = brw_perf_query(o);
  
     if (o->Ready)
        return true;
  
     switch (obj->query->kind) {
     case GEN_PERF_QUERY_TYPE_OA:
     case GEN_PERF_QUERY_TYPE_RAW:
        return (obj->oa.results_accumulated ||
                (obj->oa.bo &&
                 !brw_batch_references(&brw->batch, obj->oa.bo) &&
                 !brw_bo_busy(obj->oa.bo) &&
                 read_oa_samples_for_query(brw, obj)));
     case GEN_PERF_QUERY_TYPE_PIPELINE:
        return (obj->pipeline_stats.bo &&
                !brw_batch_references(&brw->batch, obj->pipeline_stats.bo) &&
                !brw_bo_busy(obj->pipeline_stats.bo));
  
     default:
        unreachable("Unknown query type");
        break;
     }
  
     return false;
  }
  
  static void
  read_slice_unslice_frequencies(struct brw_context *brw,
                                 struct brw_perf_query_object *obj)
  {
     const struct gen_device_info *devinfo = &brw->screen->devinfo;
     uint32_t *begin_report = obj->oa.map, *end_report = obj->oa.map + MI_RPC_BO_END_OFFSET_BYTES;
  
     gen_perf_query_result_read_frequencies(&obj->oa.result,
                                            devinfo, begin_report, end_report);
  }
  
  static void
  read_gt_frequency(struct brw_context *brw,
                    struct brw_perf_query_object *obj)
  {
     const struct gen_device_info *devinfo = &brw->screen->devinfo;
     uint32_t start = *((uint32_t *)(obj->oa.map + MI_FREQ_START_OFFSET_BYTES)),
        end = *((uint32_t *)(obj->oa.map + MI_FREQ_END_OFFSET_BYTES));
  
     switch (devinfo->gen) {
     case 7:
     case 8:
        obj->oa.gt_frequency[0] = GET_FIELD(start, GEN7_RPSTAT1_CURR_GT_FREQ) * 50ULL;
        obj->oa.gt_frequency[1] = GET_FIELD(end, GEN7_RPSTAT1_CURR_GT_FREQ) * 50ULL;
        break;
     case 9:
     case 10:
     case 11:
        obj->oa.gt_frequency[0] = GET_FIELD(start, GEN9_RPSTAT0_CURR_GT_FREQ) * 50ULL / 3ULL;
        obj->oa.gt_frequency[1] = GET_FIELD(end, GEN9_RPSTAT0_CURR_GT_FREQ) * 50ULL / 3ULL;
        break;
     default:
        unreachable("unexpected gen");
     }
  
     /* Put the numbers into Hz. */
     obj->oa.gt_frequency[0] *= 1000000ULL;
     obj->oa.gt_frequency[1] *= 1000000ULL;
  }
  
  static int
  get_oa_counter_data(struct brw_context *brw,
                      struct brw_perf_query_object *obj,
                      size_t data_size,
                      uint8_t *data)
  {
     struct gen_perf *perf = brw->perfquery.perf;
     const struct gen_perf_query_info *query = obj->query;
     int n_counters = query->n_counters;
     int written = 0;
  
     for (int i = 0; i < n_counters; i++) {
        const struct gen_perf_query_counter *counter = &query->counters[i];
        uint64_t *out_uint64;
        float *out_float;
        size_t counter_size = gen_perf_query_counter_get_size(counter);
  
        if (counter_size) {
           switch (counter->data_type) {
           case GEN_PERF_COUNTER_DATA_TYPE_UINT64:
              out_uint64 = (uint64_t *)(data + counter->offset);
              *out_uint64 =
                 counter->oa_counter_read_uint64(perf, query,
                                                 obj->oa.result.accumulator);
              break;
           case GEN_PERF_COUNTER_DATA_TYPE_FLOAT:
              out_float = (float *)(data + counter->offset);
              *out_float =
                 counter->oa_counter_read_float(perf, query,
                                                obj->oa.result.accumulator);
              break;
           default:
              /* So far we aren't using uint32, double or bool32... */
              unreachable("unexpected counter data type");
           }
           written = counter->offset + counter_size;
        }
     }
  
     return written;
  }
  
  static int
  get_pipeline_stats_data(struct brw_context *brw,
                          struct brw_perf_query_object *obj,
                          size_t data_size,
                          uint8_t *data)
  
  {
     const struct gen_perf_query_info *query = obj->query;
     int n_counters = obj->query->n_counters;
     uint8_t *p = data;
  
     uint64_t *start = brw_bo_map(brw, obj->pipeline_stats.bo, MAP_READ);
     uint64_t *end = start + (STATS_BO_END_OFFSET_BYTES / sizeof(uint64_t));
  
     for (int i = 0; i < n_counters; i++) {
        const struct gen_perf_query_counter *counter = &query->counters[i];
        uint64_t value = end[i] - start[i];
  
        if (counter->pipeline_stat.numerator !=
            counter->pipeline_stat.denominator) {
           value *= counter->pipeline_stat.numerator;
           value /= counter->pipeline_stat.denominator;
        }
  
        *((uint64_t *)p) = value;
        p += 8;
     }
  
     brw_bo_unmap(obj->pipeline_stats.bo);
  
     return p - data;
  }
  
  /**
   * Driver hook for glGetPerfQueryDataINTEL().
   */
  static void
  brw_get_perf_query_data(struct gl_context *ctx,
                          struct gl_perf_query_object *o,
                          GLsizei data_size,
                          GLuint *data,
                          GLuint *bytes_written)
  {
     struct brw_context *brw = brw_context(ctx);
     struct brw_perf_query_object *obj = brw_perf_query(o);
     int written = 0;
  
     assert(brw_is_perf_query_ready(ctx, o));
  
     DBG("GetData(%d)\n", o->Id);
  
     if (INTEL_DEBUG & DEBUG_PERFMON)
        dump_perf_queries(brw);
  
     /* We expect that the frontend only calls this hook when it knows
      * that results are available.
      */
     assert(o->Ready);
  
     switch (obj->query->kind) {
     case GEN_PERF_QUERY_TYPE_OA:
     case GEN_PERF_QUERY_TYPE_RAW:
        if (!obj->oa.results_accumulated) {
           read_gt_frequency(brw, obj);
           read_slice_unslice_frequencies(brw, obj);
           accumulate_oa_reports(brw, obj);
           assert(obj->oa.results_accumulated);
  
           brw_bo_unmap(obj->oa.bo);
           obj->oa.map = NULL;
        }
        if (obj->query->kind == GEN_PERF_QUERY_TYPE_OA) {
           written = get_oa_counter_data(brw, obj, data_size, (uint8_t *)data);
        } else {
           const struct gen_device_info *devinfo = &brw->screen->devinfo;
  
           written = gen_perf_query_result_write_mdapi((uint8_t *)data, data_size,
                                                       devinfo, &obj->oa.result,
                                                       obj->oa.gt_frequency[0],
                                                       obj->oa.gt_frequency[1]);
        }
        break;
  
     case GEN_PERF_QUERY_TYPE_PIPELINE:
        written = get_pipeline_stats_data(brw, obj, data_size, (uint8_t *)data);
        break;
  
     default:
        unreachable("Unknown query type");
        break;
     }
  
     if (bytes_written)
        *bytes_written = written;
  }
  
  static struct gl_perf_query_object *
  brw_new_perf_query_object(struct gl_context *ctx, unsigned query_index)
  {
     struct brw_context *brw = brw_context(ctx);
     const struct gen_perf_query_info *query =
        &brw->perfquery.perf->queries[query_index];
     struct brw_perf_query_object *obj =
        calloc(1, sizeof(struct brw_perf_query_object));
  
     if (!obj)
        return NULL;
  
     obj->query = query;
  
     brw->perfquery.n_query_instances++;
  
     return &obj->base;
  }
  
  /**
   * Driver hook for glDeletePerfQueryINTEL().
   */
  static void
  brw_delete_perf_query(struct gl_context *ctx,
                        struct gl_perf_query_object *o)
  {
     struct brw_context *brw = brw_context(ctx);
     struct brw_perf_query_object *obj = brw_perf_query(o);
  
     /* We can assume that the frontend waits for a query to complete
      * before ever calling into here, so we don't have to worry about
      * deleting an in-flight query object.
      */
     assert(!o->Active);
     assert(!o->Used || o->Ready);
  
     DBG("Delete(%d)\n", o->Id);
  
     switch (obj->query->kind) {
     case GEN_PERF_QUERY_TYPE_OA:
     case GEN_PERF_QUERY_TYPE_RAW:
        if (obj->oa.bo) {
           if (!obj->oa.results_accumulated) {
              drop_from_unaccumulated_query_list(brw, obj);
              dec_n_oa_users(brw);
           }
  
           brw_bo_unreference(obj->oa.bo);
           obj->oa.bo = NULL;
        }
  
        obj->oa.results_accumulated = false;
        break;
  
     case GEN_PERF_QUERY_TYPE_PIPELINE:
        if (obj->pipeline_stats.bo) {
           brw_bo_unreference(obj->pipeline_stats.bo);
           obj->pipeline_stats.bo = NULL;
        }
        break;
  
     default:
        unreachable("Unknown query type");
        break;
     }
  
     /* As an indication that the INTEL_performance_query extension is no
      * longer in use, it's a good time to free our cache of sample
      * buffers and close any current i915-perf stream.
      */
     if (--brw->perfquery.n_query_instances == 0) {
        free_sample_bufs(brw);
        close_perf(brw, obj->query);
     }
  
     free(obj);
  }
  
  /******************************************************************************/
  
  static void
  init_pipeline_statistic_query_registers(struct brw_context *brw)
  {
     const struct gen_device_info *devinfo = &brw->screen->devinfo;
     struct gen_perf *perf = brw->perfquery.perf;
     struct gen_perf_query_info *query =
        gen_perf_query_append_query_info(perf, MAX_STAT_COUNTERS);
  
     query->kind = GEN_PERF_QUERY_TYPE_PIPELINE;
     query->name = "Pipeline Statistics Registers";
  
     gen_perf_query_info_add_basic_stat_reg(query, IA_VERTICES_COUNT,
                                              "N vertices submitted");
     gen_perf_query_info_add_basic_stat_reg(query, IA_PRIMITIVES_COUNT,
                                              "N primitives submitted");
     gen_perf_query_info_add_basic_stat_reg(query, VS_INVOCATION_COUNT,
                                              "N vertex shader invocations");
  
     if (devinfo->gen == 6) {
        gen_perf_query_info_add_stat_reg(query, GEN6_SO_PRIM_STORAGE_NEEDED, 1, 1,
                                         "SO_PRIM_STORAGE_NEEDED",
                                         "N geometry shader stream-out primitives (total)");
        gen_perf_query_info_add_stat_reg(query, GEN6_SO_NUM_PRIMS_WRITTEN, 1, 1,
                                         "SO_NUM_PRIMS_WRITTEN",
                                         "N geometry shader stream-out primitives (written)");
     } else {
        gen_perf_query_info_add_stat_reg(query, GEN7_SO_PRIM_STORAGE_NEEDED(0), 1, 1,
                                         "SO_PRIM_STORAGE_NEEDED (Stream 0)",
                                         "N stream-out (stream 0) primitives (total)");
        gen_perf_query_info_add_stat_reg(query, GEN7_SO_PRIM_STORAGE_NEEDED(1), 1, 1,
                                         "SO_PRIM_STORAGE_NEEDED (Stream 1)",
                                         "N stream-out (stream 1) primitives (total)");
        gen_perf_query_info_add_stat_reg(query, GEN7_SO_PRIM_STORAGE_NEEDED(2), 1, 1,
                                         "SO_PRIM_STORAGE_NEEDED (Stream 2)",
                                         "N stream-out (stream 2) primitives (total)");
        gen_perf_query_info_add_stat_reg(query, GEN7_SO_PRIM_STORAGE_NEEDED(3), 1, 1,
                                         "SO_PRIM_STORAGE_NEEDED (Stream 3)",
                                         "N stream-out (stream 3) primitives (total)");
        gen_perf_query_info_add_stat_reg(query, GEN7_SO_NUM_PRIMS_WRITTEN(0), 1, 1,
                                         "SO_NUM_PRIMS_WRITTEN (Stream 0)",
                                         "N stream-out (stream 0) primitives (written)");
        gen_perf_query_info_add_stat_reg(query, GEN7_SO_NUM_PRIMS_WRITTEN(1), 1, 1,
                                         "SO_NUM_PRIMS_WRITTEN (Stream 1)",
                                         "N stream-out (stream 1) primitives (written)");
        gen_perf_query_info_add_stat_reg(query, GEN7_SO_NUM_PRIMS_WRITTEN(2), 1, 1,
                                         "SO_NUM_PRIMS_WRITTEN (Stream 2)",
                                         "N stream-out (stream 2) primitives (written)");
        gen_perf_query_info_add_stat_reg(query, GEN7_SO_NUM_PRIMS_WRITTEN(3), 1, 1,
                                         "SO_NUM_PRIMS_WRITTEN (Stream 3)",
                                         "N stream-out (stream 3) primitives (written)");
     }
  
     gen_perf_query_info_add_basic_stat_reg(query, HS_INVOCATION_COUNT,
                                            "N TCS shader invocations");
     gen_perf_query_info_add_basic_stat_reg(query, DS_INVOCATION_COUNT,
                                            "N TES shader invocations");
  
     gen_perf_query_info_add_basic_stat_reg(query, GS_INVOCATION_COUNT,
                                            "N geometry shader invocations");
     gen_perf_query_info_add_basic_stat_reg(query, GS_PRIMITIVES_COUNT,
                                            "N geometry shader primitives emitted");
  
     gen_perf_query_info_add_basic_stat_reg(query, CL_INVOCATION_COUNT,
                                            "N primitives entering clipping");
     gen_perf_query_info_add_basic_stat_reg(query, CL_PRIMITIVES_COUNT,
                                            "N primitives leaving clipping");
  
     if (devinfo->is_haswell || devinfo->gen == 8) {
        gen_perf_query_info_add_stat_reg(query, PS_INVOCATION_COUNT, 1, 4,
                                         "N fragment shader invocations",
                                         "N fragment shader invocations");
     } else {
        gen_perf_query_info_add_basic_stat_reg(query, PS_INVOCATION_COUNT,
                                               "N fragment shader invocations");
     }
  
     gen_perf_query_info_add_basic_stat_reg(query, PS_DEPTH_COUNT,
                                            "N z-pass fragments");
  
     if (devinfo->gen >= 7) {
        gen_perf_query_info_add_basic_stat_reg(query, CS_INVOCATION_COUNT,
                                               "N compute shader invocations");
     }
  
     query->data_size = sizeof(uint64_t) * query->n_counters;
  }
  
  static bool
  query_topology(struct brw_context *brw)
  {
     __DRIscreen *screen = brw->screen->driScrnPriv;
     struct drm_i915_query_item item = {
        .query_id = DRM_I915_QUERY_TOPOLOGY_INFO,
     };
     struct drm_i915_query query = {
        .num_items = 1,
        .items_ptr = (uintptr_t) &item,
     };
  
     if (drmIoctl(screen->fd, DRM_IOCTL_I915_QUERY, &query))
        return false;
  
     struct drm_i915_query_topology_info *topo_info =
        (struct drm_i915_query_topology_info *) calloc(1, item.length);
     item.data_ptr = (uintptr_t) topo_info;
  
     if (drmIoctl(screen->fd, DRM_IOCTL_I915_QUERY, &query) ||
         item.length <= 0)
        return false;
  
     gen_device_info_update_from_topology(&brw->screen->devinfo,
                                          topo_info);
  
     free(topo_info);
  
     return true;
  }
  
  static bool
  getparam_topology(struct brw_context *brw)
  {
     __DRIscreen *screen = brw->screen->driScrnPriv;
     drm_i915_getparam_t gp;
     int ret;
  
     int slice_mask = 0;
     gp.param = I915_PARAM_SLICE_MASK;
     gp.value = &slice_mask;
     ret = drmIoctl(screen->fd, DRM_IOCTL_I915_GETPARAM, &gp);
     if (ret)
        return false;
  
     int subslice_mask = 0;
     gp.param = I915_PARAM_SUBSLICE_MASK;
     gp.value = &subslice_mask;
     ret = drmIoctl(screen->fd, DRM_IOCTL_I915_GETPARAM, &gp);
     if (ret)
        return false;
  
     gen_device_info_update_from_masks(&brw->screen->devinfo,
                                       slice_mask,
                                       subslice_mask,
                                       brw->screen->eu_total);
  
     return true;
  }
  
  static unsigned
  brw_init_perf_query_info(struct gl_context *ctx)
  {
     struct brw_context *brw = brw_context(ctx);
     const struct gen_device_info *devinfo = &brw->screen->devinfo;
     __DRIscreen *screen = brw->screen->driScrnPriv;
  
     if (brw->perfquery.perf)
        return brw->perfquery.perf->n_queries;
  
     brw->perfquery.perf = gen_perf_new(brw, drmIoctl);
  
     init_pipeline_statistic_query_registers(brw);
     brw_perf_query_register_mdapi_statistic_query(brw);
  
     if (!query_topology(brw)) {
        /* We need the i915 query uAPI on CNL+ (kernel 4.17+). */
        if (devinfo->gen >= 10)
           return false;
  
        if (!getparam_topology(brw)) {
           /* We need the SLICE_MASK/SUBSLICE_MASK on gen8+ (kernel 4.13+). */
           if (devinfo->gen >= 8)
              return false;
  
           /* On Haswell, the values are already computed for us in
            * gen_device_info.
            */
        }
     }
  
     if (gen_perf_load_oa_metrics(brw->perfquery.perf, screen->fd, devinfo))
        brw_perf_query_register_mdapi_oa_query(brw);
  
     brw->perfquery.unaccumulated =
        ralloc_array(brw, struct brw_perf_query_object *, 2);
     brw->perfquery.unaccumulated_elements = 0;
     brw->perfquery.unaccumulated_array_size = 2;
  
     exec_list_make_empty(&brw->perfquery.sample_buffers);
     exec_list_make_empty(&brw->perfquery.free_sample_buffers);
  
     /* It's convenient to guarantee that this linked list of sample
      * buffers is never empty so we add an empty head so when we
      * Begin an OA query we can always take a reference on a buffer
      * in this list.
      */
     struct brw_oa_sample_buf *buf = get_free_sample_buf(brw);
     exec_list_push_head(&brw->perfquery.sample_buffers, &buf->link);
  
     brw->perfquery.oa_stream_fd = -1;
  
     brw->perfquery.next_query_start_report_id = 1000;
  
     return brw->perfquery.perf->n_queries;
  }
  
  void
  brw_init_performance_queries(struct brw_context *brw)
  {
     struct gl_context *ctx = &brw->ctx;
  
     ctx->Driver.InitPerfQueryInfo = brw_init_perf_query_info;
     ctx->Driver.GetPerfQueryInfo = brw_get_perf_query_info;
     ctx->Driver.GetPerfCounterInfo = brw_get_perf_counter_info;
     ctx->Driver.NewPerfQueryObject = brw_new_perf_query_object;
     ctx->Driver.DeletePerfQuery = brw_delete_perf_query;
     ctx->Driver.BeginPerfQuery = brw_begin_perf_query;
     ctx->Driver.EndPerfQuery = brw_end_perf_query;
     ctx->Driver.WaitPerfQuery = brw_wait_perf_query;
     ctx->Driver.IsPerfQueryReady = brw_is_perf_query_ready;
     ctx->Driver.GetPerfQueryData = brw_get_perf_query_data;
  }
  