src/lib/timestamp.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright (C) 2011 The ChromiumOS Authors.  All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
  18  */
  19
  20 #include <stddef.h>
  21 #include <stdint.h>
  22 #include <console/console.h>
  23 #include <cbmem.h>
  24 #include <timestamp.h>
  25 #include <arch/early_variables.h>
  26 #include <smp/node.h>
  27
  28 #define MAX_TIMESTAMPS 30
  29
  30 static struct timestamp_table* ts_table_p CAR_GLOBAL = NULL;
  31 static tsc_t ts_basetime CAR_GLOBAL = { .lo = 0, .hi =0 };
  32
  33 static void timestamp_stash(enum timestamp_id id, tsc_t ts_time);
  34
  35 static uint64_t tsc_to_uint64(tsc_t tstamp)
  36 {
  37         return (((uint64_t)tstamp.hi) << 32) + tstamp.lo;
  38 }
  39
  40 static void timestamp_real_init(tsc_t base)
  41 {
  42         struct timestamp_table* tst;
  43
  44         tst = cbmem_add(CBMEM_ID_TIMESTAMP,
  45                         sizeof(struct timestamp_table) +
  46                         MAX_TIMESTAMPS * sizeof(struct timestamp_entry));
  47
  48         if (!tst) {
  49                 printk(BIOS_ERR, "ERROR: failed to allocate timestamp table\n");
  50                 return;
  51         }
  52
  53         tst->base_time = tsc_to_uint64(base);
  54         tst->max_entries = MAX_TIMESTAMPS;
  55         tst->num_entries = 0;
  56
  57         car_set_var(ts_table_p, tst);
  58 }
  59
  60 void timestamp_add(enum timestamp_id id, tsc_t ts_time)
  61 {
  62         struct timestamp_entry *tse;
  63         struct timestamp_table *ts_table = NULL;
  64
  65         if (!boot_cpu())
  66                 return;
  67
  68         ts_table = car_get_var(ts_table_p);
  69         if (!ts_table) {
  70                 timestamp_stash(id, ts_time);
  71                 return;
  72         }
  73         if (ts_table->num_entries == ts_table->max_entries)
  74                 return;
  75
  76         tse = &ts_table->entries[ts_table->num_entries++];
  77         tse->entry_id = id;
  78         tse->entry_stamp = tsc_to_uint64(ts_time) - ts_table->base_time;
  79 }
  80
  81 void timestamp_add_now(enum timestamp_id id)
  82 {
  83         timestamp_add(id, rdtsc());
  84 }
  85
  86 #define MAX_TIMESTAMP_CACHE 8
  87 struct timestamp_cache {
  88         enum timestamp_id id;
  89         tsc_t time;
  90 } timestamp_cache[MAX_TIMESTAMP_CACHE] CAR_GLOBAL;
  91
  92 static int timestamp_entries CAR_GLOBAL = 0;
  93
  94 /**
  95  * timestamp_stash() allows to temporarily cache timestamps.
  96  * This is needed when timestamping before the CBMEM area
  97  * is initialized. The function timestamp_do_sync() is used to
  98  * write the timestamps to the CBMEM area and this is done as
  99  * part of CAR migration for romstage, and in ramstage main().
 100  */
 101
 102 static void timestamp_stash(enum timestamp_id id, tsc_t ts_time)
 103 {
 104         struct timestamp_cache *ts_cache = car_get_var(timestamp_cache);
 105         int ts_entries = car_get_var(timestamp_entries);
 106
 107         if (ts_entries >= MAX_TIMESTAMP_CACHE) {
 108                 printk(BIOS_ERR, "ERROR: failed to add timestamp to cache\n");
 109                 return;
 110         }
 111         ts_cache[ts_entries].id = id;
 112         ts_cache[ts_entries].time = ts_time;
 113         car_set_var(timestamp_entries, ++ts_entries);
 114 }
 115
 116 static void timestamp_do_sync(void)
 117 {
 118         struct timestamp_cache *ts_cache = car_get_var(timestamp_cache);
 119         int ts_entries = car_get_var(timestamp_entries);
 120
 121         int i;
 122         for (i = 0; i < ts_entries; i++)
 123                 timestamp_add(ts_cache[i].id, ts_cache[i].time);
 124         car_set_var(timestamp_entries, 0);
 125 }
 126
 127 void timestamp_init(tsc_t base)
 128 {
 129         if (!boot_cpu())
 130                 return;
 131
 132 #ifdef __PRE_RAM__
 133         /* Copy of basetime, it is too early for CBMEM. */
 134         car_set_var(ts_basetime, base);
 135 #else
 136         struct timestamp_table* tst;
 137
 138         /* Locate and use an already existing table. */
 139         tst = cbmem_find(CBMEM_ID_TIMESTAMP);
 140         if (tst) {
 141                 car_set_var(ts_table_p, tst);
 142                 return;
 143         }
 144
 145         /* Copy of basetime, may be too early for CBMEM. */
 146         car_set_var(ts_basetime, base);
 147         timestamp_real_init(base);
 148 #endif
 149 }
 150
 151 void timestamp_reinit(void)
 152 {
 153         if (!boot_cpu())
 154                 return;
 155
 156 #ifdef __PRE_RAM__
 157         timestamp_real_init(car_get_var(ts_basetime));
 158 #else
 159         if (!car_get_var(ts_table_p))
 160                 timestamp_init(car_get_var(ts_basetime));
 161 #endif
 162         if (car_get_var(ts_table_p))
 163                 timestamp_do_sync();
 164 }
 165
 166 /* Call timestamp_reinit at CAR migration time. */
 167 CAR_MIGRATE(timestamp_reinit)