[Pdbg] [PATCH 5/7] libpdbg: Add "nonexistant" pdbg target status.

[Cyril Bur]

When libpdbg runs though the device tree and calls probe() on all the
targets it marks any node (and all its children) which fails to probe
as "disabled".

When pdbg recieves arguments to specifiy a pib, core or thread (-p -c
-t) it runs though the device tree and marks nodes which do not match
the specified -p -c or -t as "disabled".

These two scenarios are related - that is we don't want to be operating
on any disabled nodes. However, they are not the same.

Consider HTM wanting to know if the machine has powersave disabled. A
simple way would be to loop through all the threads and if any of them
are not in "active" state then powersave must be enabled. In this
scenario HTM want to be able to get the status of every thread on the
machine regardless of -p -c -t flags but if the machine isn't fully
speced out and has cores which didn't probe, HTM wants to know to
ignore those threads.

This patch introduces a "nonexistant" pdbg target status which is set
during libpdbg probe() time. Later pdbg can mark nodes to targets that
do 'exist' but it would like to avoid as "disabled".

Signed-off-by: Cyril Bur <cyrilbur at gmail.com>
---
 libpdbg/libpdbg.c |  2 ++
 libpdbg/libpdbg.h |  2 +-
 libpdbg/target.c  | 10 +++++-----
 src/main.c        |  6 +++---
 src/main.h        |  3 ++-
 5 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/libpdbg/libpdbg.c b/libpdbg/libpdbg.c
index 6194048..7f8a935 100644
--- a/libpdbg/libpdbg.c
+++ b/libpdbg/libpdbg.c
@@ -69,6 +69,8 @@ enum pdbg_target_status pdbg_target_status(struct pdbg_target *target)
 		return PDBG_TARGET_DISABLED;
 	else if (!strcmp(p->prop, "hidden"))
 		return PDBG_TARGET_HIDDEN;
+	else if (!strcmp(p->prop, "nonexistant"))
+		return PDBG_TARGET_NONEXISTANT;
 	else
 		assert(0);
 }
diff --git a/libpdbg/libpdbg.h b/libpdbg/libpdbg.h
index 8dec016..d6dbcf0 100644
--- a/libpdbg/libpdbg.h
+++ b/libpdbg/libpdbg.h
@@ -9,7 +9,7 @@ struct pdbg_taget *pdbg_root_target;
 /* loops/iterators */
 struct pdbg_target *__pdbg_next_target(const char *klass, struct pdbg_target *parent, struct pdbg_target *last);
 struct pdbg_target *__pdbg_next_child_target(struct pdbg_target *parent, struct pdbg_target *last);
-enum pdbg_target_status {PDBG_TARGET_ENABLED, PDBG_TARGET_DISABLED, PDBG_TARGET_HIDDEN};
+enum pdbg_target_status {PDBG_TARGET_ENABLED, PDBG_TARGET_DISABLED, PDBG_TARGET_HIDDEN, PDBG_TARGET_NONEXISTANT};
 
 #define pdbg_for_each_target(class, parent, target)			\
 	for (target = __pdbg_next_target(class, parent, NULL);		\
diff --git a/libpdbg/target.c b/libpdbg/target.c
index 1eb85bb..790cc6e 100644
--- a/libpdbg/target.c
+++ b/libpdbg/target.c
@@ -300,7 +300,7 @@ void pdbg_targets_init(void *fdt)
 }
 
 /* Disable a node and all it's children */
-static void disable_node(struct dt_node *dn)
+static void deprobe(struct dt_node *dn)
 {
 	struct dt_node *next;
 	struct dt_property *p;
@@ -309,9 +309,9 @@ static void disable_node(struct dt_node *dn)
 	if (p)
 		dt_del_property(dn, p);
 
-	dt_add_property_string(dn, "status", "disabled");
+	dt_add_property_string(dn, "status", "nonexistant");
 	dt_for_each_child(dn, next)
-		disable_node(next);
+		deprobe(next);
 }
 
 static void _target_probe(struct dt_node *dn)
@@ -326,13 +326,13 @@ static void _target_probe(struct dt_node *dn)
 	}
 
 	p = dt_find_property(dn, "status");
-	if ((p && !strcmp(p->prop, "disabled")) || (dn->target->probe && (rc = dn->target->probe(dn->target)))) {
+	if ((p && (!strcmp(p->prop, "disabled") || !strcmp(p->prop, "nonexistant"))) || (dn->target->probe && (rc = dn->target->probe(dn->target)))) {
 		if (rc)
 			PR_DEBUG("not found\n");
 		else
 			PR_DEBUG("disabled\n");
 
-		disable_node(dn);
+		deprobe(dn);
 	} else {
 		PR_DEBUG("success\n");
 	}
diff --git a/src/main.c b/src/main.c
index 121e4ad..ae29bfa 100644
--- a/src/main.c
+++ b/src/main.c
@@ -269,7 +269,7 @@ int for_each_child_target(char *class, struct pdbg_target *parent,
 		index = pdbg_target_index(target);
 		assert(index != -1);
 		status = pdbg_target_status(target);
-		if (status == PDBG_TARGET_DISABLED || status == PDBG_TARGET_HIDDEN)
+		if (status == PDBG_TARGET_DISABLED || status == PDBG_TARGET_HIDDEN || status == PDBG_TARGET_NONEXISTANT)
 			continue;
 
 		rc += cb(target, index, arg1, arg2);
@@ -289,7 +289,7 @@ int for_each_target(char *class, int (*cb)(struct pdbg_target *, uint32_t, uint6
 		index = pdbg_target_index(target);
 		assert(index != -1);
 		status = pdbg_target_status(target);
-		if (status == PDBG_TARGET_DISABLED || status == PDBG_TARGET_HIDDEN)
+		if (status == PDBG_TARGET_DISABLED || status == PDBG_TARGET_HIDDEN || status == PDBG_TARGET_NONEXISTANT)
 			continue;
 
 		rc += cb(target, index, arg1, arg2);
@@ -420,7 +420,7 @@ void print_target(struct pdbg_target *target, int level)
 	enum pdbg_target_status status;
 
 	status = pdbg_target_status(target);
-	if (status == PDBG_TARGET_DISABLED)
+	if (status == PDBG_TARGET_DISABLED || status == PDBG_TARGET_NONEXISTANT)
 		return;
 
 	if (status == PDBG_TARGET_ENABLED) {
diff --git a/src/main.h b/src/main.h
index 71599ee..f9ea77c 100644
--- a/src/main.h
+++ b/src/main.h
@@ -21,7 +21,8 @@ enum backend { FSI, I2C, KERNEL, FAKE, HOST };
 
 static inline bool target_is_disabled(struct pdbg_target *target)
 {
-	return pdbg_target_status(target) == PDBG_TARGET_DISABLED;
+	return pdbg_target_status(target) == PDBG_TARGET_DISABLED ||
+		pdbg_target_status(target) == PDBG_TARGET_NONEXISTANT;
 }
 
 /* Returns the sum of return codes. This can be used to count how many targets the callback was run on. */
-- 
2.16.2