drivers/gpu/drm/i915/gt/selftest_gt_pm.c

   1
   2 /*
   3  * SPDX-License-Identifier: MIT
   4  *
   5  * Copyright © 2019 Intel Corporation
   6  */
   7
   8 #include <linux/sort.h>
   9
  10 #include "intel_gt_clock_utils.h"
  11
  12 #include "selftest_llc.h"
  13 #include "selftest_rc6.h"
  14 #include "selftest_rps.h"
  15
  16 static int cmp_u64(const void *A, const void *B)
  17 {
  18         const u64 *a = A, *b = B;
  19
  20         if (a < b)
  21                 return -1;
  22         else if (a > b)
  23                 return 1;
  24         else
  25                 return 0;
  26 }
  27
  28 static int cmp_u32(const void *A, const void *B)
  29 {
  30         const u32 *a = A, *b = B;
  31
  32         if (a < b)
  33                 return -1;
  34         else if (a > b)
  35                 return 1;
  36         else
  37                 return 0;
  38 }
  39
  40 static void measure_clocks(struct intel_engine_cs *engine,
  41                            u32 *out_cycles, ktime_t *out_dt)
  42 {
  43         ktime_t dt[5];
  44         u32 cycles[5];
  45         int i;
  46
  47         for (i = 0; i < 5; i++) {
  48                 preempt_disable();
  49                 cycles[i] = -ENGINE_READ_FW(engine, RING_TIMESTAMP);
  50                 dt[i] = ktime_get();
  51
  52                 udelay(1000);
  53
  54                 dt[i] = ktime_sub(ktime_get(), dt[i]);
  55                 cycles[i] += ENGINE_READ_FW(engine, RING_TIMESTAMP);
  56                 preempt_enable();
  57         }
  58
  59         /* Use the median of both cycle/dt; close enough */
  60         sort(cycles, 5, sizeof(*cycles), cmp_u32, NULL);
  61         *out_cycles = (cycles[1] + 2 * cycles[2] + cycles[3]) / 4;
  62
  63         sort(dt, 5, sizeof(*dt), cmp_u64, NULL);
  64         *out_dt = div_u64(dt[1] + 2 * dt[2] + dt[3], 4);
  65 }
  66
  67 static int live_gt_clocks(void *arg)
  68 {
  69         struct intel_gt *gt = arg;
  70         struct intel_engine_cs *engine;
  71         enum intel_engine_id id;
  72         int err = 0;
  73
  74         if (!RUNTIME_INFO(gt->i915)->cs_timestamp_frequency_hz) { /* unknown */
  75                 pr_info("CS_TIMESTAMP frequency unknown\n");
  76                 return 0;
  77         }
  78
  79         if (INTEL_GEN(gt->i915) < 4) /* Any CS_TIMESTAMP? */
  80                 return 0;
  81
  82         if (IS_GEN(gt->i915, 5))
  83                 /*
  84                  * XXX CS_TIMESTAMP low dword is dysfunctional?
  85                  *
  86                  * Ville's experiments indicate the high dword still works,
  87                  * but at a correspondingly reduced frequency.
  88                  */
  89                 return 0;
  90
  91         if (IS_GEN(gt->i915, 4))
  92                 /*
  93                  * XXX CS_TIMESTAMP appears gibberish
  94                  *
  95                  * Ville's experiments indicate that it mostly appears 'stuck'
  96                  * in that we see the register report the same cycle count
  97                  * for a couple of reads.
  98                  */
  99                 return 0;
 100
 101         intel_gt_pm_get(gt);
 102         intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
 103
 104         for_each_engine(engine, gt, id) {
 105                 u32 cycles;
 106                 u32 expected;
 107                 u64 time;
 108                 u64 dt;
 109
 110                 if (INTEL_GEN(engine->i915) < 7 && engine->id != RCS0)
 111                         continue;
 112
 113                 measure_clocks(engine, &cycles, &dt);
 114
 115                 time = i915_cs_timestamp_ticks_to_ns(engine->i915, cycles);
 116                 expected = i915_cs_timestamp_ns_to_ticks(engine->i915, dt);
 117
 118                 pr_info("%s: TIMESTAMP %d cycles [%lldns] in %lldns [%d cycles], using CS clock frequency of %uKHz\n",
 119                         engine->name, cycles, time, dt, expected,
 120                         RUNTIME_INFO(engine->i915)->cs_timestamp_frequency_hz / 1000);
 121
 122                 if (9 * time < 8 * dt || 8 * time > 9 * dt) {
 123                         pr_err("%s: CS ticks did not match walltime!\n",
 124                                engine->name);
 125                         err = -EINVAL;
 126                         break;
 127                 }
 128
 129                 if (9 * expected < 8 * cycles || 8 * expected > 9 * cycles) {
 130                         pr_err("%s: walltime did not match CS ticks!\n",
 131                                engine->name);
 132                         err = -EINVAL;
 133                         break;
 134                 }
 135         }
 136
 137         intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
 138         intel_gt_pm_put(gt);
 139
 140         return err;
 141 }
 142
 143 static int live_gt_resume(void *arg)
 144 {
 145         struct intel_gt *gt = arg;
 146         IGT_TIMEOUT(end_time);
 147         int err;
 148
 149         /* Do several suspend/resume cycles to check we don't explode! */
 150         do {
 151                 intel_gt_suspend_prepare(gt);
 152                 intel_gt_suspend_late(gt);
 153
 154                 if (gt->rc6.enabled) {
 155                         pr_err("rc6 still enabled after suspend!\n");
 156                         intel_gt_set_wedged_on_init(gt);
 157                         err = -EINVAL;
 158                         break;
 159                 }
 160
 161                 err = intel_gt_resume(gt);
 162                 if (err)
 163                         break;
 164
 165                 if (gt->rc6.supported && !gt->rc6.enabled) {
 166                         pr_err("rc6 not enabled upon resume!\n");
 167                         intel_gt_set_wedged_on_init(gt);
 168                         err = -EINVAL;
 169                         break;
 170                 }
 171
 172                 err = st_llc_verify(&gt->llc);
 173                 if (err) {
 174                         pr_err("llc state not restored upon resume!\n");
 175                         intel_gt_set_wedged_on_init(gt);
 176                         break;
 177                 }
 178         } while (!__igt_timeout(end_time, NULL));
 179
 180         return err;
 181 }
 182
 183 int intel_gt_pm_live_selftests(struct drm_i915_private *i915)
 184 {
 185         static const struct i915_subtest tests[] = {
 186                 SUBTEST(live_gt_clocks),
 187                 SUBTEST(live_rc6_manual),
 188                 SUBTEST(live_rps_clock_interval),
 189                 SUBTEST(live_rps_control),
 190                 SUBTEST(live_rps_frequency_cs),
 191                 SUBTEST(live_rps_frequency_srm),
 192                 SUBTEST(live_rps_power),
 193                 SUBTEST(live_rps_interrupt),
 194                 SUBTEST(live_rps_dynamic),
 195                 SUBTEST(live_gt_resume),
 196         };
 197
 198         if (intel_gt_is_wedged(&i915->gt))
 199                 return 0;
 200
 201         return intel_gt_live_subtests(tests, &i915->gt);
 202 }
 203
 204 int intel_gt_pm_late_selftests(struct drm_i915_private *i915)
 205 {
 206         static const struct i915_subtest tests[] = {
 207                 /*
 208                  * These tests may leave the system in an undesirable state.
 209                  * They are intended to be run last in CI and the system
 210                  * rebooted afterwards.
 211                  */
 212                 SUBTEST(live_rc6_ctx_wa),
 213         };
 214
 215         if (intel_gt_is_wedged(&i915->gt))
 216                 return 0;
 217
 218         return intel_gt_live_subtests(tests, &i915->gt);
 219 }