diff options
| author | Kyösti Mälkki <kyosti.malkki@gmail.com> | 2017-07-15 20:42:20 +0300 |
|---|---|---|
| committer | Kyösti Mälkki <kyosti.malkki@gmail.com> | 2017-07-27 06:55:03 +0000 |
| commit | 806ea08bb2868f44c5c2227dd2ace49dbe6af6a3 (patch) | |
| tree | e911f078ee58e5bbcd716a5281a74bae69defb1b /src | |
| parent | 01ea8f1fcc6e9e144de97e18afac3fb69676ba1c (diff) | |
timestamp: Apply factor to recorded stamps
If we dont have a constant TSC rate, timestamp table
has odd leaps and may appear to run backwards. Add
functionality to apply a factor such that all stamps
are in the same timebase.
Change-Id: Idab9c2c00e117c4d247db8cc9a2897640fa01edd
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/19330
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/include/timestamp.h | 5 | ||||
| -rw-r--r-- | src/lib/timestamp.c | 28 |
2 files changed, 33 insertions, 0 deletions
diff --git a/src/include/timestamp.h b/src/include/timestamp.h index d0735294df..95470f53d6 100644 --- a/src/include/timestamp.h +++ b/src/include/timestamp.h @@ -36,10 +36,15 @@ void timestamp_init(uint64_t base); void timestamp_add(enum timestamp_id id, uint64_t ts_time); /* Calls timestamp_add with current timestamp. */ void timestamp_add_now(enum timestamp_id id); + +/* Apply a factor of N/M to all timestamps recorded so far. */ +void timestamp_rescale_table(uint16_t N, uint16_t M); + #else #define timestamp_init(base) #define timestamp_add(id, time) #define timestamp_add_now(id) +#define timestamp_rescale_table(N, M) #endif /* Implemented by the architecture code */ diff --git a/src/lib/timestamp.c b/src/lib/timestamp.c index 816f28fd85..30f7c13fb8 100644 --- a/src/lib/timestamp.c +++ b/src/lib/timestamp.c @@ -299,6 +299,34 @@ static void timestamp_sync_cache_to_cbmem(int is_recovery) ts_cache->cache_state = TIMESTAMP_CACHE_NOT_NEEDED; } +void timestamp_rescale_table(uint16_t N, uint16_t M) +{ + uint32_t i; + struct timestamp_table *ts_table; + + if (!timestamp_should_run()) + return; + + if (N == 0 || M == 0) + return; + + ts_table = timestamp_table_get(); + + /* No timestamp table found */ + if (ts_table == NULL) { + printk(BIOS_ERR, "ERROR: No timestamp table found\n"); + return; + } + + ts_table->base_time /= M; + ts_table->base_time *= N; + for (i = 0; i < ts_table->num_entries; i++) { + struct timestamp_entry *tse = &ts_table->entries[i]; + tse->entry_stamp /= M; + tse->entry_stamp *= N; + } +} + ROMSTAGE_CBMEM_INIT_HOOK(timestamp_sync_cache_to_cbmem) RAMSTAGE_CBMEM_INIT_HOOK(timestamp_sync_cache_to_cbmem) |