xnu-4570.1.46.tar.gz

[apple/xnu.git] / pexpert / arm / pe_consistent_debug.c

diff --git a/pexpert/arm/pe_consistent_debug.c b/pexpert/arm/pe_consistent_debug.c
new file mode 100644 (file)
index 0000000..103a1bb
--- /dev/null
+++ b/pexpert/arm/pe_consistent_debug.c
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2011-2013 Apple Inc. All rights reserved.
+ *
+ * This document is the property of Apple Inc.
+ * It is considered confidential and proprietary.
+ *
+ * This document may not be reproduced or transmitted in any form,
+ * in whole or in part, without the express written permission of
+ * Apple Inc.
+ */
+
+#include <pexpert/pexpert.h>
+#include <pexpert/arm/consistent_debug.h>
+#include <pexpert/device_tree.h>
+#include <libkern/OSAtomic.h>
+#include <machine/machine_routines.h>
+
+static dbg_registry_t * consistent_debug_registry = NULL; 
+
+static dbg_record_header_t* consistent_debug_allocate_entry(void) {
+       unsigned int i;
+
+       if (!consistent_debug_registry)
+               return NULL;
+       for (i = 0; i < consistent_debug_registry->top_level_header.num_records; i++) {
+               dbg_record_header_t *record = &consistent_debug_registry->records[i];
+               if (OSCompareAndSwap64(kDbgIdUnusedEntry, kDbgIdReservedEntry, &record->record_id)) {
+                       // Reserved an entry at position i.
+                       return (dbg_record_header_t*)record;
+               }
+       }
+       return NULL;
+}
+
+int PE_consistent_debug_inherit(void)
+{
+       DTEntry         entryP;
+       uintptr_t       *prop_data;
+       uintptr_t       root_pointer = 0;
+       uint32_t        size;
+
+        if ((DTLookupEntry(NULL, "/chosen", &entryP) == kSuccess))
+               if (DTGetProperty(entryP, "consistent-debug-root", (void **)&prop_data, &size) == kSuccess)
+                       root_pointer = prop_data[0];
+       if (root_pointer == 0)
+               return -1;
+       consistent_debug_registry = (dbg_registry_t *)ml_map_high_window(root_pointer, sizeof(dbg_registry_t));
+       return 0;
+}
+
+int PE_consistent_debug_register(uint64_t record_id, uint64_t physaddr, uint64_t length)
+{
+       dbg_record_header_t *allocated_header = consistent_debug_allocate_entry();
+       if (allocated_header == NULL)
+               return -1;
+       allocated_header->length = length;
+       allocated_header->physaddr = physaddr;
+       // Make sure the hdr/length are visible before the record_id.
+       __asm__ volatile("dmb ish" : : : "memory");
+       allocated_header->record_id = record_id;
+       return 0;
+}
+
+int PE_consistent_debug_enabled(void)
+{
+       return (consistent_debug_registry != NULL);
+}
+