Change in coreboot[master]: timestamp: Allow timestamp_add to accept a negative number

[Bora Guvendik (Code Review)]

Bora Guvendik has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/59554 )

Change subject: timestamp: Allow timestamp_add to accept a negative number
......................................................................

timestamp: Allow timestamp_add to accept a negative number

Change timestamp_add to accept negative values for events
that took place before coreboot started executing.

TEST=Boot to OS, check cbmem -t

Signed-off-by: Bora Guvendik 
Change-Id: I90afc13a8e92693d86e3358f05e0a0cb7cdbca9b
---
M src/commonlib/include/commonlib/timestamp_serialized.h
M src/include/timestamp.h
M src/lib/timestamp.c
3 files changed, 7 insertions(+), 5 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/54/59554/1

diff --git a/src/commonlib/include/commonlib/timestamp_serialized.h b/src/commonlib/include/commonlib/timestamp_serialized.h
index 98fe552..913b09a 100644
--- a/src/commonlib/include/commonlib/timestamp_serialized.h
+++ b/src/commonlib/include/commonlib/timestamp_serialized.h
@@ -7,7 +7,7 @@

struct timestamp_entry {
    uint32_t	entry_id;
-	uint64_t	entry_stamp;
+	int64_t		entry_stamp;
 } __packed;

struct timestamp_table {
diff --git a/src/include/timestamp.h b/src/include/timestamp.h
index 647cd13..cbe9934 100644
--- a/src/include/timestamp.h
+++ b/src/include/timestamp.h
@@ -19,7 +19,7 @@
  * inside REGION(timestamp) before cbmem comes online. For later stages, timestamps
  * added before cbmem_[recovery|initialize] calls will be lost.
  */
-void timestamp_add(enum timestamp_id id, uint64_t ts_time);
+void timestamp_add(enum timestamp_id id, int64_t ts_time);
 /* Calls timestamp_add with current timestamp. */
 void timestamp_add_now(enum timestamp_id id);

diff --git a/src/lib/timestamp.c b/src/lib/timestamp.c
index 7347d07..7bc96c6 100644
--- a/src/lib/timestamp.c
+++ b/src/lib/timestamp.c
@@ -102,7 +102,7 @@
 }

static void timestamp_add_table_entry(struct timestamp_table *ts_table,
-				      enum timestamp_id id, uint64_t ts_time)
+				      enum timestamp_id id, int64_t ts_time)
 {
    struct timestamp_entry *tse;

@@ -117,7 +117,7 @@
    	printk(BIOS_ERR, "ERROR: Timestamp table full\n");
 }

-void timestamp_add(enum timestamp_id id, uint64_t ts_time)
+void timestamp_add(enum timestamp_id id, int64_t ts_time)
 {
    struct timestamp_table *ts_table;

@@ -131,7 +131,9 @@
    	return;
    }

-	ts_time -= ts_table->base_time;
+	if (ts_time >= 0)
+		ts_time -= ts_table->base_time;
+
    timestamp_add_table_entry(ts_table, id, ts_time);

if (CONFIG(TIMESTAMPS_ON_CONSOLE))