libpdbg: Add sreset command

Signed-off-by: Alistair Popple <alistair@popple.id.au>

5 files changed, 40 insertions, 1 deletions

diff --git a/libpdbg/chip.c b/libpdbg/chip.c
index 70d349d..539438a 100644
--- a/libpdbg/chip.c
+++ b/libpdbg/chip.c
@@ -115,6 +115,15 @@ int ram_stop_thread(struct target *thread_target)
 	return thread->stop(thread);
 }
 
+int ram_sreset_thread(struct target *thread_target)
+{
+	struct thread *thread;
+
+	assert(!strcmp(thread_target->class, "thread"));
+	thread = target_to_thread(thread_target);
+	return thread->sreset(thread);
+}
+
 /*
  * RAMs the opcodes in *opcodes and store the results of each opcode
  * into *results. *results must point to an array the same size as
diff --git a/libpdbg/operations.h b/libpdbg/operations.h
index 62ff5c4..2290f3b 100644
--- a/libpdbg/operations.h
+++ b/libpdbg/operations.h
@@ -68,6 +68,7 @@ uint64_t thread_status(struct thread *thread);
 int ram_stop_thread(struct target *thread);
 int ram_step_thread(struct target *thread, int count);
 int ram_start_thread(struct target *thread);
+int ram_sreset_thread(struct target *thread);
 void fsi_destroy(struct target *target);
 
 /* GDB server functionality */
diff --git a/libpdbg/p9chip.c b/libpdbg/p9chip.c
index 677401e..96ce067 100644
--- a/libpdbg/p9chip.c
+++ b/libpdbg/p9chip.c
@@ -107,6 +107,22 @@ static int p9_thread_stop(struct thread *thread)
 	return 0;
 }
 
+static int p9_thread_sreset(struct thread *thread)
+{
+	/* Can only sreset if a thread is inactive, at least on DD1 */
+	if (p9_get_thread_status(thread) != (THREAD_STATUS_QUIESCE | THREAD_STATUS_ACTIVE))
+		return 1;
+
+	/* This will force SRR1[46:47] == 0b00 which means the kernel should
+	 * enter xmon. However it will hide the fact we may have come from a
+	 * powersave state in which register contents were lost. We need a
+	 * kernel side fix for that. */
+	thread_write(thread, P9_DIRECT_CONTROL, PPC_BIT(32 + 8*thread->id));
+	thread_write(thread, P9_DIRECT_CONTROL, PPC_BIT(4 + 8*thread->id));
+
+	return 0;
+}
+
 static int p9_ram_setup(struct thread *thread)
 {
 	struct dt_node *dn;
@@ -192,6 +208,7 @@ struct thread p9_thread = {
 	},
 	.start = p9_thread_start,
 	.stop = p9_thread_stop,
+	.sreset = p9_thread_sreset,
 	.ram_setup = p9_ram_setup,
 	.ram_instruction = p9_ram_instruction,
 	.ram_destroy = p9_ram_destroy,
diff --git a/libpdbg/target.h b/libpdbg/target.h
index ba91cf5..cd7a183 100644
--- a/libpdbg/target.h
+++ b/libpdbg/target.h
@@ -112,6 +112,7 @@ struct thread {
 	int (*step)(struct thread *, int);
 	int (*start)(struct thread *);
 	int (*stop)(struct thread *);
+	int (*sreset)(struct thread *);
 
 	/* ram_setup() should be called prior to using ram_instruction() to
 	 * actually ram the instruction and return the result. ram_destroy()
diff --git a/src/main.c b/src/main.c
index 7531ce3..f1b0967 100644
--- a/src/main.c
+++ b/src/main.c
@@ -41,7 +41,7 @@ enum command { GETCFAM = 1, PUTCFAM, GETSCOM, PUTSCOM,	\
 	       GETMEM, PUTMEM, GETGPR, GETNIA, GETSPR,	\
 	       GETMSR, PUTGPR, PUTNIA, PUTSPR, PUTMSR,	\
 	       STOP, START, THREADSTATUS, STEP, PROBE,	\
-	       GETVMEM };
+	       GETVMEM, SRESET };
 
 #define MAX_CMD_ARGS 3
 enum command cmd = 0;
@@ -184,6 +184,9 @@ enum command parse_cmd(char *optarg)
 	} else if (strcmp(optarg, "stop") == 0) {
 		cmd = STOP;
 		cmd_min_arg_count = 0;
+	} else if (strcmp(optarg, "sreset") == 0) {
+		cmd = SRESET;
+		cmd_min_arg_count = 0;
 	} else if (strcmp(optarg, "threadstatus") == 0) {
 		cmd = THREADSTATUS;
 		cmd_min_arg_count = 0;
@@ -569,6 +572,11 @@ static int stop_thread(struct target *thread_target, uint32_t index, uint64_t *u
 	return ram_stop_thread(thread_target) ? 0 : 1;
 }
 
+static int sreset_thread(struct target *thread_target, uint32_t index, uint64_t *unused, uint64_t *unused1)
+{
+	return ram_sreset_thread(thread_target) ? 0 : 1;
+}
+
 static void enable_dn(struct dt_node *dn)
 {
 	struct dt_property *p;
@@ -835,6 +843,9 @@ int main(int argc, char *argv[])
 	case STOP:
 		rc = for_each_target("thread", stop_thread, NULL, NULL);
 		break;
+	case SRESET:
+		rc = for_each_target("thread", sreset_thread, NULL, NULL);
+		break;
 	case PROBE:
 		rc = 1;
 		print_target(dt_root, 0);