1 files changed, 70 insertions, 0 deletions
diff --git a/core/hwprobe.c b/core/hwprobe.c
new file mode 100644
index 0000000..0a641ad
--- /dev/null
+++ b/core/hwprobe.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+/* Copyright 2021 Stewart Smith */
+
+#define pr_fmt(fmt)  "HWPROBE: " fmt
+#include <skiboot.h>
+#include <string.h>
+
+static bool hwprobe_deps_satisfied(const struct hwprobe *hwp)
+{
+	struct hwprobe *hwprobe;
+	const char **dep;
+	unsigned int i;
+
+	dep = hwp->deps;
+	if (dep == NULL)
+		return true;
+
+
+	prlog(PR_TRACE, "Checking deps for %s\n", hwp->name);
+
+	while (*dep != NULL) {
+		prlog(PR_TRACE, "Checking %s dep %s\n", hwp->name, *dep);
+		hwprobe = &__hwprobes_start;
+		for (i = 0; &hwprobe[i] < &__hwprobes_end; i++) {
+			if(strcmp(hwprobe[i].name, *dep) == 0 &&
+			   !hwprobe[i].probed)
+				return false;
+		}
+		dep++;
+	}
+
+	prlog(PR_TRACE, "deps for %s are satisfied!\n", hwp->name);
+	return true;
+
+}
+
+void probe_hardware(void)
+{
+	struct hwprobe *hwprobe;
+	unsigned int i;
+	bool work_todo = true;
+	bool did_something = true;
+
+	while (work_todo) {
+		work_todo = false;
+		did_something = false;
+		hwprobe = &__hwprobes_start;
+		prlog(PR_DEBUG, "Begin loop\n");
+		for (i = 0; &hwprobe[i] < &__hwprobes_end; i++) {
+			if (hwprobe[i].probed)
+				continue;
+			if (hwprobe_deps_satisfied(&hwprobe[i])) {
+				prlog(PR_DEBUG, "Probing %s...\n", hwprobe[i].name);
+				if (hwprobe[i].probe)
+					hwprobe[i].probe();
+				did_something = true;
+				hwprobe[i].probed = true;
+			} else {
+				prlog(PR_DEBUG, "Dependencies for %s not yet satisfied, skipping\n",
+				      hwprobe[i].name);
+				work_todo = true;
+			}
+		}
+
+		if (work_todo && !did_something) {
+			prlog(PR_ERR, "Cannot satisfy dependencies! Bailing out\n");
+			break;
+		}
+	}
+}