TLS-lite support for i386

1 files changed, 57 insertions, 0 deletions

diff --git a/sys/arch/i386/include/tcb.h b/sys/arch/i386/include/tcb.h
new file mode 100644
index 00000000000..33f8e472cfd
--- /dev/null
+++ b/sys/arch/i386/include/tcb.h
@@ -0,0 +1,57 @@
+/*	$OpenBSD: tcb.h,v 1.1 2011/11/07 15:46:06 guenther Exp $	*/
+/*
+ * Copyright (c) 2011 Philip Guenther <guenther@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _MACHINE_TCB_H_
+#define _MACHINE_TCB_H_
+
+#ifdef _KERNEL
+
+#include <machine/sysarch.h>
+
+#define TCB_GET(p)		\
+	i386_get_threadbase(p, TSEG_GS)
+#define TCB_SET(p, addr)	\
+	i386_set_threadbase(p, (uint32_t)(addr), TSEG_GS)
+
+#else /* _KERNEL */
+
+#include <stddef.h>		/* for offsetof */
+
+/* ELF TLS ABI calls for big TCB, with static TLS data at negative offsets */
+#define TLS_VARIANT	2
+
+/* Read a slot from the TCB */
+static inline void *
+__i386_read_tcb(int offset)
+{
+	void	*val;
+	__asm__ ("movl %%gs:(%1),%0" : "=r" (val) : "r" (offset));
+	return val;
+}
+
+/* Get a pointer to the TCB itself */
+#define TCB_GET()		__i386_read_tcb(0)
+
+/* Get the value of a specific member in the TCB */
+#define TCB_GET_MEMBER(member)	\
+	__i386_read_tcb(offsetof(struct thread_control_block, member))
+
+/* Setting the TCB pointer can only be done via syscall, so no TCB_SET() */
+
+#endif /* _KERNEL */
+
+#endif /* _MACHINE_TCB_H_ */