drivers/gpu/drm/tests/drm_mm_test.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Test cases for the drm_mm range manager
   4  *
   5  * Copyright (c) 2022 Arthur Grillo <[email protected]>
   6  */
   7
   8 #include <kunit/test.h>
   9
  10 #include <linux/prime_numbers.h>
  11 #include <linux/slab.h>
  12 #include <linux/random.h>
  13 #include <linux/vmalloc.h>
  14 #include <linux/ktime.h>
  15
  16 #include <drm/drm_mm.h>
  17
  18 #include "../lib/drm_random.h"
  19
  20 enum {
  21         BEST,
  22         BOTTOMUP,
  23         TOPDOWN,
  24         EVICT,
  25 };
  26
  27 static const struct insert_mode {
  28         const char *name;
  29         enum drm_mm_insert_mode mode;
  30 } insert_modes[] = {
  31         [BEST] = { "best", DRM_MM_INSERT_BEST },
  32         [BOTTOMUP] = { "bottom-up", DRM_MM_INSERT_LOW },
  33         [TOPDOWN] = { "top-down", DRM_MM_INSERT_HIGH },
  34         [EVICT] = { "evict", DRM_MM_INSERT_EVICT },
  35         {}
  36 };
  37
  38 static bool assert_no_holes(struct kunit *test, const struct drm_mm *mm)
  39 {
  40         struct drm_mm_node *hole;
  41         u64 hole_start, __always_unused hole_end;
  42         unsigned long count;
  43
  44         count = 0;
  45         drm_mm_for_each_hole(hole, mm, hole_start, hole_end)
  46                 count++;
  47         if (count) {
  48                 KUNIT_FAIL(test,
  49                            "Expected to find no holes (after reserve), found %lu instead\n", count);
  50                 return false;
  51         }
  52
  53         drm_mm_for_each_node(hole, mm) {
  54                 if (drm_mm_hole_follows(hole)) {
  55                         KUNIT_FAIL(test, "Hole follows node, expected none!\n");
  56                         return false;
  57                 }
  58         }
  59
  60         return true;
  61 }
  62
  63 static bool assert_one_hole(struct kunit *test, const struct drm_mm *mm, u64 start, u64 end)
  64 {
  65         struct drm_mm_node *hole;
  66         u64 hole_start, hole_end;
  67         unsigned long count;
  68         bool ok = true;
  69
  70         if (end <= start)
  71                 return true;
  72
  73         count = 0;
  74         drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
  75                 if (start != hole_start || end != hole_end) {
  76                         if (ok)
  77                                 KUNIT_FAIL(test,
  78                                            "empty mm has incorrect hole, found (%llx, %llx), expect (%llx, %llx)\n",
  79                                            hole_start, hole_end, start, end);
  80                         ok = false;
  81                 }
  82                 count++;
  83         }
  84         if (count != 1) {
  85                 KUNIT_FAIL(test, "Expected to find one hole, found %lu instead\n", count);
  86                 ok = false;
  87         }
  88
  89         return ok;
  90 }
  91
  92 static u64 misalignment(struct drm_mm_node *node, u64 alignment)
  93 {
  94         u64 rem;
  95
  96         if (!alignment)
  97                 return 0;
  98
  99         div64_u64_rem(node->start, alignment, &rem);
 100         return rem;
 101 }
 102
 103 static bool assert_node(struct kunit *test, struct drm_mm_node *node, struct drm_mm *mm,
 104                         u64 size, u64 alignment, unsigned long color)
 105 {
 106         bool ok = true;
 107
 108         if (!drm_mm_node_allocated(node) || node->mm != mm) {
 109                 KUNIT_FAIL(test, "node not allocated\n");
 110                 ok = false;
 111         }
 112
 113         if (node->size != size) {
 114                 KUNIT_FAIL(test, "node has wrong size, found %llu, expected %llu\n",
 115                            node->size, size);
 116                 ok = false;
 117         }
 118
 119         if (misalignment(node, alignment)) {
 120                 KUNIT_FAIL(test,
 121                            "node is misaligned, start %llx rem %llu, expected alignment %llu\n",
 122                            node->start, misalignment(node, alignment), alignment);
 123                 ok = false;
 124         }
 125
 126         if (node->color != color) {
 127                 KUNIT_FAIL(test, "node has wrong color, found %lu, expected %lu\n",
 128                            node->color, color);
 129                 ok = false;
 130         }
 131
 132         return ok;
 133 }
 134
 135 static void drm_test_mm_init(struct kunit *test)
 136 {
 137         const unsigned int size = 4096;
 138         struct drm_mm mm;
 139         struct drm_mm_node tmp;
 140
 141         /* Start with some simple checks on initialising the struct drm_mm */
 142         memset(&mm, 0, sizeof(mm));
 143         KUNIT_ASSERT_FALSE_MSG(test, drm_mm_initialized(&mm),
 144                                "zeroed mm claims to be initialized\n");
 145
 146         memset(&mm, 0xff, sizeof(mm));
 147         drm_mm_init(&mm, 0, size);
 148         if (!drm_mm_initialized(&mm)) {
 149                 KUNIT_FAIL(test, "mm claims not to be initialized\n");
 150                 goto out;
 151         }
 152
 153         if (!drm_mm_clean(&mm)) {
 154                 KUNIT_FAIL(test, "mm not empty on creation\n");
 155                 goto out;
 156         }
 157
 158         /* After creation, it should all be one massive hole */
 159         if (!assert_one_hole(test, &mm, 0, size)) {
 160                 KUNIT_FAIL(test, "");
 161                 goto out;
 162         }
 163
 164         memset(&tmp, 0, sizeof(tmp));
 165         tmp.start = 0;
 166         tmp.size = size;
 167         if (drm_mm_reserve_node(&mm, &tmp)) {
 168                 KUNIT_FAIL(test, "failed to reserve whole drm_mm\n");
 169                 goto out;
 170         }
 171
 172         /* After filling the range entirely, there should be no holes */
 173         if (!assert_no_holes(test, &mm)) {
 174                 KUNIT_FAIL(test, "");
 175                 goto out;
 176         }
 177
 178         /* And then after emptying it again, the massive hole should be back */
 179         drm_mm_remove_node(&tmp);
 180         if (!assert_one_hole(test, &mm, 0, size)) {
 181                 KUNIT_FAIL(test, "");
 182                 goto out;
 183         }
 184
 185 out:
 186         drm_mm_takedown(&mm);
 187 }
 188
 189 static void drm_test_mm_debug(struct kunit *test)
 190 {
 191         struct drm_mm mm;
 192         struct drm_mm_node nodes[2];
 193
 194         /* Create a small drm_mm with a couple of nodes and a few holes, and
 195          * check that the debug iterator doesn't explode over a trivial drm_mm.
 196          */
 197
 198         drm_mm_init(&mm, 0, 4096);
 199
 200         memset(nodes, 0, sizeof(nodes));
 201         nodes[0].start = 512;
 202         nodes[0].size = 1024;
 203         KUNIT_ASSERT_FALSE_MSG(test, drm_mm_reserve_node(&mm, &nodes[0]),
 204                                "failed to reserve node[0] {start=%lld, size=%lld)\n",
 205                                nodes[0].start, nodes[0].size);
 206
 207         nodes[1].size = 1024;
 208         nodes[1].start = 4096 - 512 - nodes[1].size;
 209         KUNIT_ASSERT_FALSE_MSG(test, drm_mm_reserve_node(&mm, &nodes[1]),
 210                                "failed to reserve node[0] {start=%lld, size=%lld)\n",
 211                                nodes[0].start, nodes[0].size);
 212 }
 213
 214 static bool expect_insert(struct kunit *test, struct drm_mm *mm,
 215                           struct drm_mm_node *node, u64 size, u64 alignment, unsigned long color,
 216                         const struct insert_mode *mode)
 217 {
 218         int err;
 219
 220         err = drm_mm_insert_node_generic(mm, node,
 221                                          size, alignment, color,
 222                                          mode->mode);
 223         if (err) {
 224                 KUNIT_FAIL(test,
 225                            "insert (size=%llu, alignment=%llu, color=%lu, mode=%s) failed with err=%d\n",
 226                            size, alignment, color, mode->name, err);
 227                 return false;
 228         }
 229
 230         if (!assert_node(test, node, mm, size, alignment, color)) {
 231                 drm_mm_remove_node(node);
 232                 return false;
 233         }
 234
 235         return true;
 236 }
 237
 238 static void drm_test_mm_align_pot(struct kunit *test, int max)
 239 {
 240         struct drm_mm mm;
 241         struct drm_mm_node *node, *next;
 242         int bit;
 243
 244         /* Check that we can align to the full u64 address space */
 245
 246         drm_mm_init(&mm, 1, U64_MAX - 2);
 247
 248         for (bit = max - 1; bit; bit--) {
 249                 u64 align, size;
 250
 251                 node = kzalloc(sizeof(*node), GFP_KERNEL);
 252                 if (!node) {
 253                         KUNIT_FAIL(test, "failed to allocate node");
 254                         goto out;
 255                 }
 256
 257                 align = BIT_ULL(bit);
 258                 size = BIT_ULL(bit - 1) + 1;
 259                 if (!expect_insert(test, &mm, node, size, align, bit, &insert_modes[0])) {
 260                         KUNIT_FAIL(test, "insert failed with alignment=%llx [%d]", align, bit);
 261                         goto out;
 262                 }
 263
 264                 cond_resched();
 265         }
 266
 267 out:
 268         drm_mm_for_each_node_safe(node, next, &mm) {
 269                 drm_mm_remove_node(node);
 270                 kfree(node);
 271         }
 272         drm_mm_takedown(&mm);
 273 }
 274
 275 static void drm_test_mm_align32(struct kunit *test)
 276 {
 277         drm_test_mm_align_pot(test, 32);
 278 }
 279
 280 static void drm_test_mm_align64(struct kunit *test)
 281 {
 282         drm_test_mm_align_pot(test, 64);
 283 }
 284
 285 static void drm_test_mm_once(struct kunit *test, unsigned int mode)
 286 {
 287         struct drm_mm mm;
 288         struct drm_mm_node rsvd_lo, rsvd_hi, node;
 289
 290         drm_mm_init(&mm, 0, 7);
 291
 292         memset(&rsvd_lo, 0, sizeof(rsvd_lo));
 293         rsvd_lo.start = 1;
 294         rsvd_lo.size = 1;
 295         if (drm_mm_reserve_node(&mm, &rsvd_lo)) {
 296                 KUNIT_FAIL(test, "Could not reserve low node\n");
 297                 goto err;
 298         }
 299
 300         memset(&rsvd_hi, 0, sizeof(rsvd_hi));
 301         rsvd_hi.start = 5;
 302         rsvd_hi.size = 1;
 303         if (drm_mm_reserve_node(&mm, &rsvd_hi)) {
 304                 KUNIT_FAIL(test, "Could not reserve low node\n");
 305                 goto err_lo;
 306         }
 307
 308         if (!drm_mm_hole_follows(&rsvd_lo) || !drm_mm_hole_follows(&rsvd_hi)) {
 309                 KUNIT_FAIL(test, "Expected a hole after lo and high nodes!\n");
 310                 goto err_hi;
 311         }
 312
 313         memset(&node, 0, sizeof(node));
 314         if (drm_mm_insert_node_generic(&mm, &node, 2, 0, 0, mode)) {
 315                 KUNIT_FAIL(test, "Could not insert the node into the available hole!\n");
 316                 goto err_hi;
 317         }
 318
 319         drm_mm_remove_node(&node);
 320 err_hi:
 321         drm_mm_remove_node(&rsvd_hi);
 322 err_lo:
 323         drm_mm_remove_node(&rsvd_lo);
 324 err:
 325         drm_mm_takedown(&mm);
 326 }
 327
 328 static void drm_test_mm_lowest(struct kunit *test)
 329 {
 330         drm_test_mm_once(test, DRM_MM_INSERT_LOW);
 331 }
 332
 333 static void drm_test_mm_highest(struct kunit *test)
 334 {
 335         drm_test_mm_once(test, DRM_MM_INSERT_HIGH);
 336 }
 337
 338 static struct kunit_case drm_mm_tests[] = {
 339         KUNIT_CASE(drm_test_mm_init),
 340         KUNIT_CASE(drm_test_mm_debug),
 341         KUNIT_CASE(drm_test_mm_align32),
 342         KUNIT_CASE(drm_test_mm_align64),
 343         KUNIT_CASE(drm_test_mm_lowest),
 344         KUNIT_CASE(drm_test_mm_highest),
 345         {}
 346 };
 347
 348 static struct kunit_suite drm_mm_test_suite = {
 349         .name = "drm_mm",
 350         .test_cases = drm_mm_tests,
 351 };
 352
 353 kunit_test_suite(drm_mm_test_suite);
 354
 355 MODULE_AUTHOR("Intel Corporation");
 356 MODULE_LICENSE("GPL");