[Pdbg] [PATCH 17/18] htm: Change buffer wrappings semantics

[Michael Neuling]

"htm record" is set to non-wrapping mode
"htm start" is in wrapping mode since it's assumed "htm stop" will
stop it.

Signed-off-by: Michael Neuling <mikey at neuling.org>
---
 libpdbg/htm.c | 33 ++++++++++++++++++++++-----------
 src/htm.c     |  4 ++--
 2 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/libpdbg/htm.c b/libpdbg/htm.c
index a6445c2420..c4eeabbb59 100644
--- a/libpdbg/htm.c
+++ b/libpdbg/htm.c
@@ -436,9 +436,9 @@ static int configure_debugfs_memtrace(struct htm *htm)
 	return 0;
 }
 
-static int configure_chtm(struct htm *htm)
+static int configure_chtm(struct htm *htm, bool wrap)
 {
-	uint64_t hid0, ncu;
+	uint64_t hid0, ncu, val;
 
 	if (!pdbg_target_is_class(&htm->target, "chtm"))
 		return 0;
@@ -446,8 +446,9 @@ static int configure_chtm(struct htm *htm)
 	if (HTM_ERR(configure_debugfs_memtrace(htm)))
 		return -1;
 
+	val = wrap ? HTM_MODE_WRAP : 0;
 	if (HTM_ERR(pib_write(&htm->target, HTM_COLLECTION_MODE,
-		HTM_MODE_ENABLE)))
+		HTM_MODE_ENABLE | val)))
 		return -1;
 
 	if (HTM_ERR(pib_read(htm->target.parent, HID0_REGISTER, &hid0)))
@@ -493,7 +494,7 @@ static int deconfigure_chtm(struct htm *htm)
 	return 0;
 }
 
-static int configure_nhtm(struct htm *htm)
+static int configure_nhtm(struct htm *htm, bool wrap)
 {
 	uint64_t val;
 
@@ -507,10 +508,11 @@ static int configure_nhtm(struct htm *htm)
 	 * The constant is the VGTARGET field, taken from a cronus
 	 * booted system which presumably set it up correctly
 	 */
+	val = wrap ? HTM_MODE_WRAP : 0;
 	if (HTM_ERR(pib_write(&htm->target, HTM_COLLECTION_MODE,
 					HTM_MODE_ENABLE |
 					NHTM_MODE_CRESP_PRECISE |
-					HTM_MODE_WRAP |
+					val |
 					0xFFFF000000)))
 		return -1;
 
@@ -710,7 +712,7 @@ static int configure_memory(struct htm *htm)
 	return 0;
 }
 
-static int do_htm_reset(struct htm *htm)
+static int do_htm_reset(struct htm *htm, bool wrap)
 {
 	struct htm_status status;
 
@@ -718,9 +720,9 @@ static int do_htm_reset(struct htm *htm)
 		return -1;
 
 	if (!is_resetable(&status) || !is_configured(htm)) {
-		if (configure_nhtm(htm) < 0)
+		if (configure_nhtm(htm, wrap) < 0)
 			return -1;
-		if (configure_chtm(htm) < 0)
+		if (configure_chtm(htm, wrap) < 0)
 			return -1;
 	}
 
@@ -755,11 +757,11 @@ static int htm_toggle_debug_bit(struct htm *htm)
 	return 0;
 }
 
-static int do_htm_start(struct htm *htm)
+static int __do_htm_start(struct htm *htm, bool wrap)
 {
 	struct htm_status status;
 
-	if (do_htm_reset(htm) < 0)
+	if (do_htm_reset(htm, wrap) < 0)
 		return -1;
 
 	if (HTM_ERR(get_status(htm, &status)))
@@ -790,6 +792,11 @@ static int do_htm_start(struct htm *htm)
 	return 1;
 }
 
+static int do_htm_start(struct htm *htm)
+{
+	return __do_htm_start(htm, true);
+}
+
 static int do_htm_stop(struct htm *htm)
 {
 	struct htm_status status;
@@ -926,6 +933,10 @@ static int do_htm_status(struct htm *htm)
 	return 1;
 }
 
+/*
+ * FIXME:
+ *   Look for eyecatcher 0xacef_f000 at start, otherwise assume wrapping
+ */
 static int do_htm_dump(struct htm *htm, uint64_t size, char *filename)
 {
 	char *trace_file;
@@ -1008,7 +1019,7 @@ static int do_htm_dump(struct htm *htm, uint64_t size, char *filename)
 
 static int do_htm_record(struct htm *htm, char *filename)
 {
-	if (do_htm_start(htm) < 0)
+	if (__do_htm_start(htm, false) < 0)
 		return -1;
 
 	if (htm_wait_complete(htm))
diff --git a/src/htm.c b/src/htm.c
index eff46a6c93..02e55c1833 100644
--- a/src/htm.c
+++ b/src/htm.c
@@ -86,7 +86,7 @@ static int run_start(enum htm_type type)
 		if (target_is_disabled(target))
 			continue;
 
-		printf("Starting HTM@");
+		printf("Starting with buffer wrapping HTM@");
 		print_htm_address(type, target);
 		if (htm_start(target) != 1) {
 			printf("Couldn't start HTM@");
@@ -195,7 +195,7 @@ static int run_record(enum htm_type type)
 			return 0;
 
 		/* size = 0 will dump everything */
-		printf("Recording HTM@");
+		printf("Recording till buffer wraps HTM@");
 		print_htm_address(type, target);
 		if (htm_record(target, filename) != 1) {
 			printf("Couldn't record HTM@");
-- 
2.17.1