[Pdbg] [PATCH] libpdbg: ensure thread state validity, only print requested targets

[Nicholas Piggin]

Thread state is not queried from the target each time, but cached.
This patch adds a valid flag in the thread state cache to ensure
this is being probed proprly before use.

This also skips threads that were not targetted when printing thread
status.

Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
 libpdbg/chip.c    | 2 ++
 libpdbg/libpdbg.h | 1 +
 libpdbg/p8chip.c  | 3 +++
 libpdbg/p9chip.c  | 4 ++++
 src/thread.c      | 9 +++++++++
 5 files changed, 19 insertions(+)

diff --git a/libpdbg/chip.c b/libpdbg/chip.c
index 079592c..2103b2e 100644
--- a/libpdbg/chip.c
+++ b/libpdbg/chip.c
@@ -98,6 +98,8 @@ struct thread_state thread_status(struct pdbg_target *target)
 
 	assert(!strcmp(target->class, "thread"));
 	thread = target_to_thread(target);
+	assert(thread->status.valid);
+
 	return thread->status;
 }
 
diff --git a/libpdbg/libpdbg.h b/libpdbg/libpdbg.h
index 1c345cb..39d12e8 100644
--- a/libpdbg/libpdbg.h
+++ b/libpdbg/libpdbg.h
@@ -156,6 +156,7 @@ enum pdbg_sleep_state {PDBG_THREAD_STATE_RUN, PDBG_THREAD_STATE_DOZE,
 enum pdbg_smt_state {PDBG_SMT_UNKNOWN, PDBG_SMT_1, PDBG_SMT_2, PDBG_SMT_4, PDBG_SMT_8};
 
 struct thread_state {
+	bool valid;
 	bool active;
 	bool quiesced;
 	enum pdbg_sleep_state sleep_state;
diff --git a/libpdbg/p8chip.c b/libpdbg/p8chip.c
index 3e90c8d..453a6f4 100644
--- a/libpdbg/p8chip.c
+++ b/libpdbg/p8chip.c
@@ -125,6 +125,9 @@ static struct thread_state get_thread_status(struct thread *thread)
 	uint64_t val, mode_reg;
 	struct thread_state thread_status;
 
+	memset(&thread_status, 0, sizeof(thread_status));
+	thread_status.valid = true;
+
 	/* Need to activete debug mode to get complete status */
 	pib_read(&thread->target, RAS_MODE_REG, &mode_reg);
 	pib_write(&thread->target, RAS_MODE_REG, mode_reg | MR_THREAD_IN_DEBUG);
diff --git a/libpdbg/p9chip.c b/libpdbg/p9chip.c
index 1433d19..f1e22cf 100644
--- a/libpdbg/p9chip.c
+++ b/libpdbg/p9chip.c
@@ -97,6 +97,9 @@ static struct thread_state p9_get_thread_status(struct thread *thread)
 	uint64_t value;
 	struct thread_state thread_state;
 
+	memset(&thread_state, 0, sizeof(thread_state));
+	thread_state.valid = true;
+
 	thread_read(thread, P9_RAS_STATUS, &value);
 
 	thread_state.quiesced = (GETFIELD(PPC_BITMASK(8*thread->id, 3 + 8*thread->id), value) == 0xf);
@@ -121,6 +124,7 @@ static int p9_thread_probe(struct pdbg_target *target)
 
 	thread->id = dt_prop_get_u32(target, "tid");
 	thread->status = p9_get_thread_status(thread);
+	assert(thread->status.valid);
 
 	return 0;
 }
diff --git a/src/thread.c b/src/thread.c
index 4b95636..2625874 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -15,6 +15,7 @@
  */
 #include <errno.h>
 #include <inttypes.h>
+#include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -28,6 +29,7 @@ static int print_thread_status(struct pdbg_target *target, uint32_t index, uint6
 	struct thread_state *status = (struct thread_state *) arg;
 
 	status[index] = thread_status(target);
+
 	return 1;
 }
 
@@ -36,12 +38,19 @@ static int print_core_thread_status(struct pdbg_target *core_target, uint32_t in
 	struct thread_state status[8];
 	int i, rc;
 
+	memset(status, 0, sizeof(status));
+
 	printf("c%02d:  ", index);
 
 	/* TODO: This cast is gross. Need to rewrite for_each_child_target as an iterator. */
 	rc = for_each_child_target("thread", core_target, print_thread_status, (uint64_t *) &status[0], NULL);
 	for (i = 0; i <= *maxindex; i++) {
 
+		if (!status[i].valid) {
+			printf("    ");
+			continue;
+		}
+
 		if (status[i].active)
 			printf("A");
 		else
-- 
2.17.0