src/lib/timestamp.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <assert.h>
   4 #include <stdint.h>
   5 #include <console/console.h>
   6 #include <cbmem.h>
   7 #include <symbols.h>
   8 #include <timer.h>
   9 #include <timestamp.h>
  10 #include <smp/node.h>
  11
  12 #define MAX_TIMESTAMPS 192
  13
  14 /* This points to the active timestamp_table and can change within a stage
  15    as CBMEM comes available. */
  16 static struct timestamp_table *glob_ts_table;
  17
  18 static void timestamp_cache_init(struct timestamp_table *ts_cache,
  19                                  uint64_t base)
  20 {
  21         ts_cache->num_entries = 0;
  22         ts_cache->base_time = base;
  23         ts_cache->max_entries = (REGION_SIZE(timestamp) -
  24                 offsetof(struct timestamp_table, entries))
  25                 / sizeof(struct timestamp_entry);
  26 }
  27
  28 static struct timestamp_table *timestamp_cache_get(void)
  29 {
  30         struct timestamp_table *ts_cache = NULL;
  31
  32         if (!ENV_ROMSTAGE_OR_BEFORE)
  33                 return NULL;
  34
  35         if (REGION_SIZE(timestamp) < sizeof(*ts_cache)) {
  36                 BUG();
  37         } else {
  38                 ts_cache = (void *)_timestamp;
  39         }
  40
  41         return ts_cache;
  42 }
  43
  44 static struct timestamp_table *timestamp_alloc_cbmem_table(void)
  45 {
  46         struct timestamp_table *tst;
  47
  48         tst = cbmem_add(CBMEM_ID_TIMESTAMP,
  49                         sizeof(struct timestamp_table) +
  50                         MAX_TIMESTAMPS * sizeof(struct timestamp_entry));
  51
  52         if (!tst)
  53                 return NULL;
  54
  55         tst->base_time = 0;
  56         tst->max_entries = MAX_TIMESTAMPS;
  57         tst->num_entries = 0;
  58
  59         return tst;
  60 }
  61
  62 /* Determine if one should proceed into timestamp code. This is for protecting
  63  * systems that have multiple processors running in romstage -- namely AMD
  64  * based x86 platforms. */
  65 static int timestamp_should_run(void)
  66 {
  67         /*
  68          * Only check boot_cpu() in other stages than
  69          * ENV_PAYLOAD_LOADER on x86.
  70          */
  71         if ((!ENV_PAYLOAD_LOADER && ENV_X86) && !boot_cpu())
  72                 return 0;
  73
  74         return 1;
  75 }
  76
  77 static struct timestamp_table *timestamp_table_get(void)
  78 {
  79         if (glob_ts_table)
  80                 return glob_ts_table;
  81
  82         glob_ts_table = timestamp_cache_get();
  83
  84         return glob_ts_table;
  85 }
  86
  87 static void timestamp_table_set(struct timestamp_table *ts)
  88 {
  89         glob_ts_table = ts;
  90 }
  91
  92 static const char *timestamp_name(enum timestamp_id id)
  93 {
  94         int i;
  95
  96         for (i = 0; i < ARRAY_SIZE(timestamp_ids); i++) {
  97                 if (timestamp_ids[i].id == id)
  98                         return timestamp_ids[i].name;
  99         }
 100
 101         return "Unknown timestamp ID";
 102 }
 103
 104 static void timestamp_add_table_entry(struct timestamp_table *ts_table,
 105                                       enum timestamp_id id, int64_t ts_time)
 106 {
 107         struct timestamp_entry *tse;
 108
 109         if (ts_table->num_entries >= ts_table->max_entries)
 110                 return;
 111
 112         tse = &ts_table->entries[ts_table->num_entries++];
 113         tse->entry_id = id;
 114         tse->entry_stamp = ts_time;
 115
 116         if (ts_table->num_entries == ts_table->max_entries)
 117                 printk(BIOS_ERR, "Timestamp table full\n");
 118 }
 119
 120 void timestamp_add(enum timestamp_id id, int64_t ts_time)
 121 {
 122         struct timestamp_table *ts_table;
 123
 124         if (!timestamp_should_run())
 125                 return;
 126
 127         ts_table = timestamp_table_get();
 128
 129         if (!ts_table) {
 130                 printk(BIOS_ERR, "No timestamp table found\n");
 131                 return;
 132         }
 133
 134         ts_time -= ts_table->base_time;
 135         timestamp_add_table_entry(ts_table, id, ts_time);
 136
 137         if (CONFIG(TIMESTAMPS_ON_CONSOLE))
 138                 printk(BIOS_INFO, "Timestamp - %s: %lld\n", timestamp_name(id), ts_time);
 139 }
 140
 141 void timestamp_add_now(enum timestamp_id id)
 142 {
 143         timestamp_add(id, timestamp_get());
 144 }
 145
 146 void timestamp_init(uint64_t base)
 147 {
 148         struct timestamp_table *ts_cache;
 149
 150         assert(ENV_ROMSTAGE_OR_BEFORE);
 151
 152         if (!timestamp_should_run())
 153                 return;
 154
 155         ts_cache = timestamp_cache_get();
 156
 157         if (!ts_cache) {
 158                 printk(BIOS_ERR, "No timestamp cache to init\n");
 159                 return;
 160         }
 161
 162         timestamp_cache_init(ts_cache, base);
 163         timestamp_table_set(ts_cache);
 164 }
 165
 166 static void timestamp_sync_cache_to_cbmem(struct timestamp_table *ts_cbmem_table)
 167 {
 168         uint32_t i;
 169         struct timestamp_table *ts_cache_table;
 170
 171         ts_cache_table = timestamp_table_get();
 172         if (!ts_cache_table) {
 173                 printk(BIOS_ERR, "No timestamp cache found\n");
 174                 return;
 175         }
 176
 177         /*
 178          * There's no need to worry about the base_time fields being out of
 179          * sync because only the following configuration is used/supported:
 180          *
 181          *    Timestamps get initialized before ramstage, which implies
 182          *    CBMEM initialization in romstage.
 183          *    This requires the board to define a TIMESTAMP() region in its
 184          *    memlayout.ld (default on x86). The base_time from timestamp_init()
 185          *    (usually called from bootblock.c on most non-x86 boards) persists
 186          *    in that region until it gets synced to CBMEM in romstage.
 187          *    In ramstage, the BSS cache's base_time will be 0 until the second
 188          *    sync, which will adjust the timestamps in there to the correct
 189          *    base_time (from CBMEM) with the timestamp_add_table_entry() below.
 190          *
 191          * If you try to initialize timestamps before ramstage but don't define
 192          * a TIMESTAMP region, all operations will fail (safely), and coreboot
 193          * will behave as if timestamps collection was disabled.
 194          */
 195
 196         /* Inherit cache base_time. */
 197         ts_cbmem_table->base_time = ts_cache_table->base_time;
 198
 199         for (i = 0; i < ts_cache_table->num_entries; i++) {
 200                 struct timestamp_entry *tse = &ts_cache_table->entries[i];
 201                 timestamp_add_table_entry(ts_cbmem_table, tse->entry_id,
 202                                           tse->entry_stamp);
 203         }
 204
 205         /* Cache no longer required. */
 206         ts_cache_table->num_entries = 0;
 207 }
 208
 209 static void timestamp_reinit(int is_recovery)
 210 {
 211         struct timestamp_table *ts_cbmem_table;
 212
 213         if (!timestamp_should_run())
 214                 return;
 215
 216         /* First time into romstage we make a clean new table. For platforms that travel
 217            through this path on resume, ARCH_X86 S3, timestamps are also reset. */
 218         if (ENV_CREATES_CBMEM) {
 219                 ts_cbmem_table = timestamp_alloc_cbmem_table();
 220         } else {
 221                 /* Find existing table in cbmem. */
 222                 ts_cbmem_table = cbmem_find(CBMEM_ID_TIMESTAMP);
 223         }
 224
 225         if (ts_cbmem_table == NULL) {
 226                 printk(BIOS_ERR, "No timestamp table allocated\n");
 227                 timestamp_table_set(NULL);
 228                 return;
 229         }
 230
 231         if (ENV_CREATES_CBMEM)
 232                 timestamp_sync_cache_to_cbmem(ts_cbmem_table);
 233
 234         /* Seed the timestamp tick frequency in ENV_PAYLOAD_LOADER. */
 235         if (ENV_PAYLOAD_LOADER)
 236                 ts_cbmem_table->tick_freq_mhz = timestamp_tick_freq_mhz();
 237
 238         timestamp_table_set(ts_cbmem_table);
 239 }
 240
 241 void timestamp_rescale_table(uint16_t N, uint16_t M)
 242 {
 243         uint32_t i;
 244         struct timestamp_table *ts_table;
 245
 246         if (!timestamp_should_run())
 247                 return;
 248
 249         if (N == 0 || M == 0)
 250                 return;
 251
 252         ts_table = timestamp_table_get();
 253
 254         /* No timestamp table found */
 255         if (ts_table == NULL) {
 256                 printk(BIOS_ERR, "No timestamp table found\n");
 257                 return;
 258         }
 259
 260         ts_table->base_time /= M;
 261         ts_table->base_time *= N;
 262         for (i = 0; i < ts_table->num_entries; i++) {
 263                 struct timestamp_entry *tse = &ts_table->entries[i];
 264                 tse->entry_stamp /= M;
 265                 tse->entry_stamp *= N;
 266         }
 267 }
 268
 269 /*
 270  * Get the time in microseconds since boot (or more precise: since timestamp
 271  * table was initialized).
 272  */
 273 uint32_t get_us_since_boot(void)
 274 {
 275         struct timestamp_table *ts = timestamp_table_get();
 276
 277         if (ts == NULL || ts->tick_freq_mhz == 0)
 278                 return 0;
 279         return (timestamp_get() - ts->base_time) / ts->tick_freq_mhz;
 280 }
 281
 282 CBMEM_READY_HOOK(timestamp_reinit);
 283
 284 /* Provide default timestamp implementation using monotonic timer. */
 285 uint64_t  __weak timestamp_get(void)
 286 {
 287         struct mono_time t1, t2;
 288
 289         if (!CONFIG(HAVE_MONOTONIC_TIMER))
 290                 return 0;
 291
 292         mono_time_set_usecs(&t1, 0);
 293         timer_monotonic_get(&t2);
 294
 295         return mono_time_diff_microseconds(&t1, &t2);
 296 }
 297
 298 /* Like timestamp_get() above this matches up with microsecond granularity. */
 299 int __weak timestamp_tick_freq_mhz(void)
 300 {
 301         return 1;
 302 }