Initial import

1 files changed, 231 insertions, 0 deletions

diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h
new file mode 100644
index 000000000..caa51ff85
--- /dev/null
+++ b/arch/nios2/include/asm/uaccess.h
@@ -0,0 +1,231 @@
+/*
+ * User space memory access functions for Nios II
+ *
+ * Copyright (C) 2010-2011, Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2009, Wind River Systems Inc
+ *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef _ASM_NIOS2_UACCESS_H
+#define _ASM_NIOS2_UACCESS_H
+
+#include <linux/errno.h>
+#include <linux/thread_info.h>
+#include <linux/string.h>
+
+#include <asm/page.h>
+
+#define VERIFY_READ	0
+#define VERIFY_WRITE	1
+
+/*
+ * The exception table consists of pairs of addresses: the first is the
+ * address of an instruction that is allowed to fault, and the second is
+ * the address at which the program should continue.  No registers are
+ * modified, so it is entirely up to the continuation code to figure out
+ * what to do.
+ *
+ * All the routines below use bits of fixup code that are out of line
+ * with the main instruction path.  This means when everything is well,
+ * we don't even have to jump over them.  Further, they do not intrude
+ * on our cache or tlb entries.
+ */
+struct exception_table_entry {
+	unsigned long insn;
+	unsigned long fixup;
+};
+
+extern int fixup_exception(struct pt_regs *regs);
+
+/*
+ * Segment stuff
+ */
+#define MAKE_MM_SEG(s)		((mm_segment_t) { (s) })
+#define USER_DS			MAKE_MM_SEG(0x80000000UL)
+#define KERNEL_DS		MAKE_MM_SEG(0)
+
+#define get_ds()		(KERNEL_DS)
+
+#define get_fs()		(current_thread_info()->addr_limit)
+#define set_fs(seg)		(current_thread_info()->addr_limit = (seg))
+
+#define segment_eq(a, b)	((a).seg == (b).seg)
+
+#define __access_ok(addr, len)			\
+	(((signed long)(((long)get_fs().seg) &	\
+		((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0)
+
+#define access_ok(type, addr, len)		\
+	likely(__access_ok((unsigned long)(addr), (unsigned long)(len)))
+
+# define __EX_TABLE_SECTION	".section __ex_table,\"a\"\n"
+
+/*
+ * Zero Userspace
+ */
+
+static inline unsigned long __must_check __clear_user(void __user *to,
+						      unsigned long n)
+{
+	__asm__ __volatile__ (
+		"1:     stb     zero, 0(%1)\n"
+		"       addi    %0, %0, -1\n"
+		"       addi    %1, %1, 1\n"
+		"       bne     %0, zero, 1b\n"
+		"2:\n"
+		__EX_TABLE_SECTION
+		".word  1b, 2b\n"
+		".previous\n"
+		: "=r" (n), "=r" (to)
+		: "0" (n), "1" (to)
+	);
+
+	return n;
+}
+
+static inline unsigned long __must_check clear_user(void __user *to,
+						    unsigned long n)
+{
+	if (!access_ok(VERIFY_WRITE, to, n))
+		return n;
+	return __clear_user(to, n);
+}
+
+extern long __copy_from_user(void *to, const void __user *from,
+				unsigned long n);
+extern long __copy_to_user(void __user *to, const void *from, unsigned long n);
+
+static inline long copy_from_user(void *to, const void __user *from,
+				unsigned long n)
+{
+	if (!access_ok(VERIFY_READ, from, n))
+		return n;
+	return __copy_from_user(to, from, n);
+}
+
+static inline long copy_to_user(void __user *to, const void *from,
+				unsigned long n)
+{
+	if (!access_ok(VERIFY_WRITE, to, n))
+		return n;
+	return __copy_to_user(to, from, n);
+}
+
+extern long strncpy_from_user(char *__to, const char __user *__from,
+				long __len);
+extern long strnlen_user(const char __user *s, long n);
+
+#define __copy_from_user_inatomic	__copy_from_user
+#define __copy_to_user_inatomic		__copy_to_user
+
+/* Optimized macros */
+#define __get_user_asm(val, insn, addr, err)				\
+{									\
+	__asm__ __volatile__(						\
+	"       movi    %0, %3\n"					\
+	"1:   " insn " %1, 0(%2)\n"					\
+	"       movi     %0, 0\n"					\
+	"2:\n"								\
+	"       .section __ex_table,\"a\"\n"				\
+	"       .word 1b, 2b\n"						\
+	"       .previous"						\
+	: "=&r" (err), "=r" (val)					\
+	: "r" (addr), "i" (-EFAULT));					\
+}
+
+#define __get_user_unknown(val, size, ptr, err) do {			\
+	err = 0;							\
+	if (copy_from_user(&(val), ptr, size)) {			\
+		err = -EFAULT;						\
+	}								\
+	} while (0)
+
+#define __get_user_common(val, size, ptr, err)				\
+do {									\
+	switch (size) {							\
+	case 1:								\
+		__get_user_asm(val, "ldbu", ptr, err);			\
+		break;							\
+	case 2:								\
+		__get_user_asm(val, "ldhu", ptr, err);			\
+		break;							\
+	case 4:								\
+		__get_user_asm(val, "ldw", ptr, err);			\
+		break;							\
+	default:							\
+		__get_user_unknown(val, size, ptr, err);		\
+		break;							\
+	}								\
+} while (0)
+
+#define __get_user(x, ptr)						\
+	({								\
+	long __gu_err = -EFAULT;					\
+	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);		\
+	unsigned long __gu_val;						\
+	__get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
+	(x) = (__force __typeof__(x))__gu_val;				\
+	__gu_err;							\
+	})
+
+#define get_user(x, ptr)						\
+({									\
+	long __gu_err = -EFAULT;					\
+	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);		\
+	unsigned long __gu_val = 0;					\
+	if (access_ok(VERIFY_READ,  __gu_ptr, sizeof(*__gu_ptr)))	\
+		__get_user_common(__gu_val, sizeof(*__gu_ptr),		\
+			__gu_ptr, __gu_err);				\
+	(x) = (__force __typeof__(x))__gu_val;				\
+	__gu_err;							\
+})
+
+#define __put_user_asm(val, insn, ptr, err)				\
+{									\
+	__asm__ __volatile__(						\
+	"       movi    %0, %3\n"					\
+	"1:   " insn " %1, 0(%2)\n"					\
+	"       movi     %0, 0\n"					\
+	"2:\n"								\
+	"       .section __ex_table,\"a\"\n"				\
+	"       .word 1b, 2b\n"						\
+	"       .previous\n"						\
+	: "=&r" (err)							\
+	: "r" (val), "r" (ptr), "i" (-EFAULT));				\
+}
+
+#define put_user(x, ptr)						\
+({									\
+	long __pu_err = -EFAULT;					\
+	__typeof__(*(ptr)) __user *__pu_ptr = (ptr);			\
+	__typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x);		\
+	if (access_ok(VERIFY_WRITE, __pu_ptr, sizeof(*__pu_ptr))) {	\
+		switch (sizeof(*__pu_ptr)) {				\
+		case 1:							\
+			__put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
+			break;						\
+		case 2:							\
+			__put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
+			break;						\
+		case 4:							\
+			__put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
+			break;						\
+		default:						\
+			/* XXX: This looks wrong... */			\
+			__pu_err = 0;					\
+			if (copy_to_user(__pu_ptr, &(__pu_val),		\
+				sizeof(*__pu_ptr)))			\
+				__pu_err = -EFAULT;			\
+			break;						\
+		}							\
+	}								\
+	__pu_err;							\
+})
+
+#define __put_user(x, ptr) put_user(x, ptr)
+
+#endif /* _ASM_NIOS2_UACCESS_H */