Add timestamp collecting to coreboot.

This patch adds code to initialize the time stamp collection
facility in coreboot. It adds a table in the CBMEM section, which
provides the base timer reading value (all other readings are
offsets of this one) and an array of timestamp id/timestamp value
pairs.

Just two values are being added now, this will have to be used
more extensively and also integrated into payloads to provide more
comprehensive boot process time measurements.

Also, since the CBMEM area could already contain a section (from the
previous run, before reset), when processing a section addition
request we should check if a section already exists and return its
address, if so.

Change-Id: I7ed9f5c400bc5432f228348b41fd19a67c36d533
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: http://review.coreboot.org/713
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Tested-by: build bot (Jenkins)

1 files changed, 17 insertions, 0 deletions

diff --git a/src/lib/cbmem.c b/src/lib/cbmem.c
index f5c3d3a811..659784079b 100644
--- a/src/lib/cbmem.c
+++ b/src/lib/cbmem.c
@@ -118,6 +118,22 @@ void *cbmem_add(u32 id, u64 size)
 {
 	struct cbmem_entry *cbmem_toc;
 	int i;
+	void *p;
+
+	/*
+	 * This could be a restart, check if the section is there already. It
+	 * is remotely possible that the dram contents persisted over the
+	 * bootloader upgrade AND the same section now needs more room, but
+	 * this is quite a remote possibility and it is ignored here.
+	 */
+	p = cbmem_find(id);
+	if (p) {
+		printk(BIOS_NOTICE,
+		       "CBMEM section %x: using existing location at %p.\n",
+		       id, p);
+		return p;
+	}
+
 	cbmem_toc = get_cbmem_toc();
 
 	if (cbmem_toc == NULL) {
@@ -240,6 +256,7 @@ void cbmem_list(void)
 		case CBMEM_ID_MPTABLE:	 printk(BIOS_DEBUG, "SMP TABLE  "); break;
 		case CBMEM_ID_RESUME:	 printk(BIOS_DEBUG, "ACPI RESUME"); break;
 		case CBMEM_ID_SMBIOS:    printk(BIOS_DEBUG, "SMBIOS     "); break;
+		case CBMEM_ID_TIMESTAMP: printk(BIOS_DEBUG, "TIME STAMP "); break;
 		default: printk(BIOS_DEBUG, "%08x ", cbmem_toc[i].id);
 		}
 		printk(BIOS_DEBUG, "%08llx ", cbmem_toc[i].base);