1 files changed, 111 insertions, 0 deletions
diff --git a/newlib/libc/machine/amdgcn/mlock.c b/newlib/libc/machine/amdgcn/mlock.c
new file mode 100644
index 000000000..4848c978c
--- /dev/null
+++ b/newlib/libc/machine/amdgcn/mlock.c
@@ -0,0 +1,111 @@
+/*
+ * Support file for AMDGCN in newlib.
+ * Copyright (c) 2017 Mentor Graphics.
+ *
+ * The authors hereby grant permission to use, copy, modify, distribute,
+ * and license this software and its documentation for any purpose, provided
+ * that existing copyright notices are retained in all copies and that this
+ * notice is included verbatim in any distributions. No written agreement,
+ * license, or royalty fee is required for any of the authorized uses.
+ * Modifications to this software may be copyrighted by their authors
+ * and need not follow the licensing terms described here, provided that
+ * the new terms are clearly indicated on the first page of each file where
+ * they apply.
+ */
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <reent.h>
+
+/* _sbrk_r expects us to use the real errno, not the reentrant one.  */
+#include <errno.h>
+#undef errno
+extern int errno;
+
+/* The runtime passes in heap space like this.  */
+struct heap {
+  int64_t size;
+  char data[0];
+};
+
+static char *__heap_ptr = (char*)-1;
+static char *__heap_end = (char*)-1;
+static int __heap_lock = 0;
+static void *__heap_lock_id = NULL;
+static int __heap_lock_cnt = 0;
+
+void *
+sbrk (ptrdiff_t nbytes)
+{
+  if (__heap_ptr == (char *)-1)
+    {
+      /* Find the heap from kernargs.
+         The kernargs pointer is in s[8:9].
+	 This will break if the enable_sgpr_* flags are ever changed.  */
+      char *kernargs;
+      asm ("s_mov_b64 %0, s[8:9]" : "=Sg"(kernargs));
+
+      /* The heap data is at kernargs[3].  */
+      struct heap *heap = *(struct heap **)(kernargs + 24);
+
+      __heap_ptr = heap->data;
+      __heap_end = __heap_ptr + heap->size;
+    }
+
+  if ((__heap_ptr + nbytes) >= __heap_end)
+    {
+      errno = ENOMEM;
+      return (void*)-1;
+    }
+
+  char *base = __heap_ptr;
+  __heap_ptr += nbytes;
+
+  return base;
+}
+
+void
+__malloc_lock (struct _reent *reent)
+{
+  void *id = reent;
+
+  if (id == __heap_lock_id)
+    {
+      if (__heap_lock_cnt < 1)
+	abort ();
+      ++__heap_lock_cnt;
+      return;
+    }
+
+  while (__sync_lock_test_and_set (&__heap_lock, 1))
+    /* A sleep seems like it should allow the wavefront to yeild (maybe?)
+       Use the shortest possible sleep time of 1*64 cycles.  */
+    asm volatile ("s_sleep\t1" ::: "memory");
+
+  if (__heap_lock_id != NULL)
+    abort ();
+  if (__heap_lock_cnt != 0)
+    abort ();
+
+  __heap_lock_cnt = 1;
+  __heap_lock_id = id;
+}
+
+void
+__malloc_unlock (struct _reent *reent)
+{
+  void *id = reent;
+
+  if (id != __heap_lock_id)
+    abort ();
+  if (__heap_lock_cnt < 1)
+    abort ();
+
+  --__heap_lock_cnt;
+
+  if (__heap_lock_cnt > 0)
+    return;
+
+  __heap_lock_id = NULL;
+  __sync_lock_release (&__heap_lock);
+}