--- /dev/null
+/*
+ * 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 */
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