From 806ea08bb2868f44c5c2227dd2ace49dbe6af6a3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ky=C3=B6sti=20M=C3=A4lkki?= Date: Sat, 15 Jul 2017 20:42:20 +0300 Subject: timestamp: Apply factor to recorded stamps MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-on: https://review.coreboot.org/19330 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin --- src/lib/timestamp.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'src/lib/timestamp.c') 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) -- cgit v1.2.3