New upstream version 17.08

[deb_dpdk.git] / examples / performance-thread / common / arch / arm64 / stack.h

diff --git a/examples/performance-thread/common/arch/arm64/stack.h b/examples/performance-thread/common/arch/arm64/stack.h
new file mode 100644 (file)
index 0000000..fa3b31e
--- /dev/null
+++ b/examples/performance-thread/common/arch/arm64/stack.h
@@ -0,0 +1,84 @@
+/*
+ *   BSD LICENSE
+ *
+ *   Copyright (C) Cavium, Inc. 2017.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Cavium, Inc nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef STACK_H
+#define STACK_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "lthread_int.h"
+
+/*
+ * Sets up the initial stack for the lthread.
+ */
+static inline void
+arch_set_stack(struct lthread *lt, void *func)
+{
+       void **stack_top = (void *)((char *)(lt->stack) + lt->stack_size);
+
+       /*
+        * Align stack_top to 16 bytes. Arm64 has the constraint that the
+        * stack pointer must always be quad-word aligned.
+        */
+       stack_top = (void **)(((unsigned long)(stack_top)) & ~0xfUL);
+
+       /*
+        * First Stack Frame
+        */
+       stack_top[0] = NULL;
+       stack_top[-1] = NULL;
+
+       /*
+        * Initialize the context
+        */
+       lt->ctx.fp = &stack_top[-1];
+       lt->ctx.sp = &stack_top[-2];
+
+       /*
+        * Here only the address of _lthread_exec is saved as the link
+        * register value. The argument to _lthread_exec i.e the address of
+        * the lthread struct is not saved. This is because the first
+        * argument to ctx_switch is the address of the new context,
+        * which also happens to be the address of required lthread struct.
+        * So while returning from ctx_switch into _thread_exec, parameter
+        * register x0 will always contain the required value.
+        */
+       lt->ctx.lr = func;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* STACK_H_ */