src/arch/x86/acpi.c: Create log area and extend TPM2 table

According to newest TCG ACPI Specification for Family 1.2 and 2.0
Version 1.2, Revision 8, TPM2 ACPI table has two more fields LAML and LASA.

Update the table structure definition, create the log area for TPM2 in
coreboot tables and fill the missing fields in TPM2 table. TPM2 should be
now probed well in SeaBIOS rel-1.12.0 or master.

Tested on apu2 with Infineon SLB9665 TT2.0.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Change-Id: Ie482cba0a3093aae996f7431251251f145fe64f3
Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/29800
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
diff --git a/src/arch/x86/acpi.c b/src/arch/x86/acpi.c
index f54aa19..3b33f1b 100644
--- a/src/arch/x86/acpi.c
+++ b/src/arch/x86/acpi.c
@@ -308,12 +308,47 @@
 	header->checksum = acpi_checksum((void *)tcpa, header->length);
 }
 
+static void *get_tpm2_log(u32 *size)
+{
+	const struct cbmem_entry *ce;
+	const u32 tpm2_default_log_len = 0x10000;
+	void *lasa;
+	ce = cbmem_entry_find(CBMEM_ID_TPM2_TCG_LOG);
+	if (ce) {
+		lasa = cbmem_entry_start(ce);
+		*size = cbmem_entry_size(ce);
+		printk(BIOS_DEBUG, "TPM2 log found at %p\n", lasa);
+		return lasa;
+	}
+	lasa = cbmem_add(CBMEM_ID_TPM2_TCG_LOG, tpm2_default_log_len);
+	if (!lasa) {
+		printk(BIOS_ERR, "TPM2 log creation failed\n");
+		return NULL;
+	}
+
+	printk(BIOS_DEBUG, "TPM2 log created at %p\n", lasa);
+	memset(lasa, 0, tpm2_default_log_len);
+
+	*size = tpm2_default_log_len;
+	return lasa;
+}
+
 static void acpi_create_tpm2(acpi_tpm2_t *tpm2)
 {
 	acpi_header_t *header = &(tpm2->header);
+	u32 tpm2_log_len;
+	void *lasa;
 
 	memset((void *)tpm2, 0, sizeof(acpi_tpm2_t));
 
+	/*
+	 * Some payloads like SeaBIOS depend on log area to use TPM2.
+	 * Get the memory size and address of TPM2 log area or initialize it.
+	 */
+	lasa = get_tpm2_log(&tpm2_log_len);
+	if (!lasa)
+		tpm2_log_len = 0;
+
 	/* Fill out header fields. */
 	memcpy(header->signature, "TPM2", 4);
 	memcpy(header->oem_id, OEM_ID, 6);
@@ -331,6 +366,10 @@
 	tpm2->start_method = 6;
 	memset(tpm2->msp, 0, sizeof(tpm2->msp));
 
+	/* Fill the log area size and start address fields. */
+	tpm2->laml = tpm2_log_len;
+	tpm2->lasa = (uintptr_t) lasa;
+
 	/* Calculate checksum. */
 	header->checksum = acpi_checksum((void *)tpm2, header->length);
 }