x86/xen: Consolidate xen-os.h in a single place

amd64 and i386 platform code contain very similar xen/xen-os.h

The only differences are:
 - Functions/variables/types which were unused in i386/xen/xen-os.h:
    * xen_xchg
    * __xchg_dummy
    * __xg
    * __xchg
    * atomic_t
    * atomic_inc
    * rdtscll

The functions/variables/types unused in xen-os.h can be dropped and there
is no more differences betwen amd64 and i386.

The new header is placed in x86/include/xen and each platform will have
dummy headers include x86/xen/*.h. This is to be able to include
machine/xen/*.h in the PV drivers.

Submitted by:		Julien Grall <julien.grall@citrix.com>
Reviewed by:		royger
Differential Revision:	https://reviews.freebsd.org/D3880
Sponsored by:		Citrix Systems R&D

1 files changed, 132 insertions, 0 deletions

diff --git a/sys/x86/include/xen/xen-os.h b/sys/x86/include/xen/xen-os.h
new file mode 100644
index 0000000..f37f325
--- /dev/null
+++ b/sys/x86/include/xen/xen-os.h
@@ -0,0 +1,132 @@
+/*****************************************************************************
+ * x86/xen/xen-os.h
+ *
+ * Random collection of macros and definition
+ *
+ * Copyright (c) 2003, 2004 Keir Fraser (on behalf of the Xen team)
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _MACHINE_X86_XEN_XEN_OS_H_
+#define _MACHINE_X86_XEN_XEN_OS_H_
+
+#ifdef PAE
+#define CONFIG_X86_PAE
+#endif
+
+/* Everything below this point is not included by assembler (.S) files. */
+#ifndef __ASSEMBLY__
+
+/* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
+static inline void rep_nop(void)
+{
+    __asm__ __volatile__ ( "rep;nop" : : : "memory" );
+}
+#define cpu_relax() rep_nop()
+
+/* This is a barrier for the compiler only, NOT the processor! */
+#define barrier() __asm__ __volatile__("": : :"memory")
+
+#define LOCK_PREFIX ""
+#define LOCK ""
+#define ADDR (*(volatile long *) addr)
+
+/**
+ * test_and_clear_bit - Clear a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.
+ * It also implies a memory barrier.
+ */
+static __inline int test_and_clear_bit(int nr, volatile void * addr)
+{
+        int oldbit;
+
+        __asm__ __volatile__( LOCK_PREFIX
+                "btrl %2,%1\n\tsbbl %0,%0"
+                :"=r" (oldbit),"=m" (ADDR)
+                :"Ir" (nr) : "memory");
+        return oldbit;
+}
+
+static __inline int constant_test_bit(int nr, const volatile void * addr)
+{
+    return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
+}
+
+static __inline int variable_test_bit(int nr, volatile void * addr)
+{
+    int oldbit;
+
+    __asm__ __volatile__(
+        "btl %2,%1\n\tsbbl %0,%0"
+        :"=r" (oldbit)
+        :"m" (ADDR),"Ir" (nr));
+    return oldbit;
+}
+
+#define test_bit(nr,addr) \
+(__builtin_constant_p(nr) ? \
+ constant_test_bit((nr),(addr)) : \
+ variable_test_bit((nr),(addr)))
+
+/**
+ * set_bit - Atomically set a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * This function is atomic and may not be reordered.  See __set_bit()
+ * if you do not require the atomic guarantees.
+ * Note that @nr may be almost arbitrarily large; this function is not
+ * restricted to acting on a single-word quantity.
+ */
+static __inline__ void set_bit(int nr, volatile void * addr)
+{
+        __asm__ __volatile__( LOCK_PREFIX
+                "btsl %1,%0"
+                :"=m" (ADDR)
+                :"Ir" (nr));
+}
+
+/**
+ * clear_bit - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * clear_bit() is atomic and may not be reordered.  However, it does
+ * not contain a memory barrier, so if it is used for locking purposes,
+ * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
+ * in order to ensure changes are visible on other processors.
+ */
+static __inline__ void clear_bit(int nr, volatile void * addr)
+{
+        __asm__ __volatile__( LOCK_PREFIX
+                "btrl %1,%0"
+                :"=m" (ADDR)
+                :"Ir" (nr));
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _MACHINE_X86_XEN_XEN_OS_H_ */