[SLOF] [PATCH 04/16] Add initial support for logging

[Stefan Berger]

This patch adds initial support for the logging that will be done
following measurements done by further code added to SLOF.

Signed-off-by: Stefan Berger <stefanb at linux.vnet.ibm.com>
Reviewed-by: Nikunj A Dadhania <nikunj at linux.vnet.ibm.com>
---
 board-qemu/slof/vtpm-sml.fs |  3 +++
 lib/libtpm/tcgbios.c        | 30 ++++++++++++++++++++++++++++++
 lib/libtpm/tcgbios.h        |  1 +
 lib/libtpm/tpm.code         | 11 +++++++++++
 lib/libtpm/tpm.in           |  1 +
 5 files changed, 46 insertions(+)

diff --git a/board-qemu/slof/vtpm-sml.fs b/board-qemu/slof/vtpm-sml.fs
index 72edac0..741a953 100644
--- a/board-qemu/slof/vtpm-sml.fs
+++ b/board-qemu/slof/vtpm-sml.fs
@@ -25,6 +25,9 @@ LOG-SIZE alloc-mem to log-base
 \ create /ibm,vtpm
 s" ibm,vtpm" 2dup device-name device-type
 
+\ convey logbase and size to the C driver
+log-base LOG-SIZE tpm-set-log-parameters
+
 : sml-get-allocated-size ( -- buffer-size)
     vtpm-debug? IF
         ." Call to sml-get-allocated-size; size = " LOG-SIZE . cr
diff --git a/lib/libtpm/tcgbios.c b/lib/libtpm/tcgbios.c
index efa4cdf..afbaede 100644
--- a/lib/libtpm/tcgbios.c
+++ b/lib/libtpm/tcgbios.c
@@ -77,10 +77,40 @@ static struct tpm_state tpm_state = {
 
 extern struct tpm_driver tpm_drivers[];
 
+static void *log_base;
+static uint32_t log_area_size;
+
 /********************************************************
   Extensions for TCG-enabled BIOS
  *******************************************************/
 
+void tpm_set_log_parameters(void *addr, unsigned int size)
+{
+	dprintf("Log is at 0x%llx; size is %u bytes\n",
+		(uint64_t)addr, size);
+	log_base = addr;
+	log_area_size = size;
+}
+
+static uint8_t *get_log_base_ptr(void)
+{
+	return log_base;
+}
+
+static uint32_t get_log_area_size(void)
+{
+	return log_area_size;
+}
+
+/* clear the OpenFirmware device tree log */
+static void reset_ofdt_log(void)
+{
+	uint8_t *log_area_start_address = get_log_base_ptr();
+
+	if (log_area_start_address)
+		memset(log_area_start_address, 0, get_log_area_size());
+}
+
 static bool is_tpm_present(void)
 {
 	bool rc = false;
diff --git a/lib/libtpm/tcgbios.h b/lib/libtpm/tcgbios.h
index c4c462e..9b51826 100644
--- a/lib/libtpm/tcgbios.h
+++ b/lib/libtpm/tcgbios.h
@@ -17,5 +17,6 @@
 
 uint32_t tpm_start(void);
 uint32_t tpm_unassert_pp(void);
+void tpm_set_log_parameters(void *address, unsigned int size);
 
 #endif /* TCGBIOS_H */
diff --git a/lib/libtpm/tpm.code b/lib/libtpm/tpm.code
index 567b384..a6b66a8 100644
--- a/lib/libtpm/tpm.code
+++ b/lib/libtpm/tpm.code
@@ -35,3 +35,14 @@ PRIM(tpm_X2d_unassert_X2d_pp)
 	PUSH;
 	TOS.n = tpm_unassert_pp();
 MIRP
+
+/*************************************************************/
+/* Convey log address and size                               */
+/* SLOF:   tpm-set-log-parameters  ( addr size -- )          */
+/* LIBTPM: tpm_set_log_parameters(void *addr, uint64_t size) */
+/*************************************************************/
+PRIM(tpm_X2d_set_X2d_log_X2d_parameters)
+	int size = TOS.u; POP;
+	void *addr = TOS.a; POP;
+	tpm_set_log_parameters(addr, size);
+MIRP
diff --git a/lib/libtpm/tpm.in b/lib/libtpm/tpm.in
index 266439e..a2f7cb9 100644
--- a/lib/libtpm/tpm.in
+++ b/lib/libtpm/tpm.in
@@ -15,3 +15,4 @@
 
 cod(tpm-start)
 cod(tpm-unassert-pp)
+cod(tpm-set-log-parameters)
-- 
1.9.3