1 files changed, 126 insertions, 0 deletions
diff --git a/arch/hexagon/include/asm/system.h b/arch/hexagon/include/asm/system.h
new file mode 100644
index 00000000000..323ed1dd65e
--- /dev/null
+++ b/arch/hexagon/include/asm/system.h
@@ -0,0 +1,126 @@
+/*
+ * System level definitions for the Hexagon architecture
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef _ASM_SYSTEM_H
+#define _ASM_SYSTEM_H
+
+#include <linux/linkage.h>
+#include <linux/irqflags.h>
+#include <asm/atomic.h>
+#include <asm/hexagon_vm.h>
+
+struct thread_struct;
+
+extern struct task_struct *__switch_to(struct task_struct *,
+	struct task_struct *,
+	struct task_struct *);
+
+#define switch_to(p, n, r) do {\
+	r = __switch_to((p), (n), (r));\
+} while (0)
+
+
+#define rmb()				barrier()
+#define read_barrier_depends()		barrier()
+#define wmb()				barrier()
+#define mb()				barrier()
+#define smp_rmb()			barrier()
+#define smp_read_barrier_depends()	barrier()
+#define smp_wmb()			barrier()
+#define smp_mb()			barrier()
+#define smp_mb__before_atomic_dec()	barrier()
+#define smp_mb__after_atomic_dec()	barrier()
+#define smp_mb__before_atomic_inc()	barrier()
+#define smp_mb__after_atomic_inc()	barrier()
+
+/*
+ * __xchg - atomically exchange a register and a memory location
+ * @x: value to swap
+ * @ptr: pointer to memory
+ * @size:  size of the value
+ *
+ * Only 4 bytes supported currently.
+ *
+ * Note:  there was an errata for V2 about .new's and memw_locked.
+ *
+ */
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
+				   int size)
+{
+	unsigned long retval;
+
+	/*  Can't seem to use printk or panic here, so just stop  */
+	if (size != 4) do { asm volatile("brkpt;\n"); } while (1);
+
+	__asm__ __volatile__ (
+	"1:	%0 = memw_locked(%1);\n"    /*  load into retval */
+	"	memw_locked(%1,P0) = %2;\n" /*  store into memory */
+	"	if !P0 jump 1b;\n"
+	: "=&r" (retval)
+	: "r" (ptr), "r" (x)
+	: "memory", "p0"
+	);
+	return retval;
+}
+
+/*
+ * Atomically swap the contents of a register with memory.  Should be atomic
+ * between multiple CPU's and within interrupts on the same CPU.
+ */
+#define xchg(ptr, v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v), (ptr), \
+	sizeof(*(ptr))))
+
+/*  Set a value and use a memory barrier.  Used by the scheduler somewhere.  */
+#define set_mb(var, value) \
+	do { var = value; mb(); } while (0)
+
+/*
+ *  see rt-mutex-design.txt; cmpxchg supposedly checks if *ptr == A and swaps.
+ *  looks just like atomic_cmpxchg on our arch currently with a bunch of
+ *  variable casting.
+ */
+#define __HAVE_ARCH_CMPXCHG 1
+
+#define cmpxchg(ptr, old, new)					\
+({								\
+	__typeof__(ptr) __ptr = (ptr);				\
+	__typeof__(*(ptr)) __old = (old);			\
+	__typeof__(*(ptr)) __new = (new);			\
+	__typeof__(*(ptr)) __oldval = 0;			\
+								\
+	asm volatile(						\
+		"1:	%0 = memw_locked(%1);\n"		\
+		"	{ P0 = cmp.eq(%0,%2);\n"		\
+		"	  if (!P0.new) jump:nt 2f; }\n"		\
+		"	memw_locked(%1,p0) = %3;\n"		\
+		"	if (!P0) jump 1b;\n"			\
+		"2:\n"						\
+		: "=&r" (__oldval)				\
+		: "r" (__ptr), "r" (__old), "r" (__new)		\
+		: "memory", "p0"				\
+	);							\
+	__oldval;						\
+})
+
+/*  Should probably shoot for an 8-byte aligned stack pointer  */
+#define STACK_MASK (~7)
+#define arch_align_stack(x) (x & STACK_MASK)
+
+#endif