The patch adds "user access from kernel" codes.
Signed-off-by: Guo Ren
Cc: Arnd Bergmann
---
arch/csky/include/asm/uaccess.h | 416
arch/csky/lib/usercopy.c| 262 +
2 files changed, 678 insertions(+)
create mode 100644 arch/csky/include/asm/uaccess.h
create mode 100644 arch/csky/lib/usercopy.c
diff --git a/arch/csky/include/asm/uaccess.h b/arch/csky/include/asm/uaccess.h
new file mode 100644
index 000..acaf0e210
--- /dev/null
+++ b/arch/csky/include/asm/uaccess.h
@@ -0,0 +1,416 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#ifndef __ASM_CSKY_UACCESS_H
+#define __ASM_CSKY_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#define VERIFY_READ0
+#define VERIFY_WRITE 1
+
+static inline int access_ok(int type, const void *addr, unsigned long size)
+{
+ unsigned long limit = current_thread_info()->addr_limit.seg;
+
+ return (((unsigned long)addr < limit) &&
+ ((unsigned long)(addr + size) < limit));
+}
+
+static inline int verify_area(int type, const void *addr, unsigned long size)
+{
+ return access_ok(type, addr, size) ? 0 : -EFAULT;
+}
+
+#define __addr_ok(addr) (access_ok(VERIFY_READ, addr, 0))
+
+extern int __put_user_bad(void);
+
+/*
+ * Tell gcc we read from memory instead of writing: this is because
+ * we do not write to any memory gcc knows about, so there are no
+ * aliasing issues.
+ */
+
+/*
+ * These are the main single-value transfer routines. They automatically
+ * use the right size if we just have the right pointer type.
+ *
+ * This gets kind of ugly. We want to return _two_ values in "get_user()"
+ * and yet we don't want to do any pointers, because that is too much
+ * of a performance impact. Thus we have a few rather ugly macros here,
+ * and hide all the ugliness from the user.
+ *
+ * The "__xxx" versions of the user access functions are versions that
+ * do not verify the address space, that must have been done previously
+ * with a separate "access_ok()" call (this is used when we do multiple
+ * accesses to the same area of user memory).
+ *
+ * As we use the same address space for kernel and user data on
+ * Ckcore, we can just do these as direct assignments. (Of course, the
+ * exception handling means that it's no longer "just"...)
+ */
+
+#define put_user(x, ptr) \
+ __put_user_check((x), (ptr), sizeof(*(ptr)))
+
+#define __put_user(x, ptr) \
+ __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+#define __ptr(x) ((unsigned long *)(x))
+
+#define get_user(x, ptr) \
+ __get_user_check((x), (ptr), sizeof(*(ptr)))
+
+#define __get_user(x, ptr) \
+ __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
+
+#define __put_user_nocheck(x, ptr, size) \
+({ \
+ long __pu_err = 0; \
+ typeof(*(ptr)) *__pu_addr = (ptr); \
+ typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x); \
+ if (__pu_addr) \
+ __put_user_size(__pu_val, (__pu_addr), (size), \
+ __pu_err); \
+ __pu_err; \
+})
+
+#define __put_user_check(x, ptr, size) \
+({ \
+ long __pu_err = -EFAULT;\
+ typeof(*(ptr)) *__pu_addr = (ptr); \
+ typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x); \
+ if (access_ok(VERIFY_WRITE, __pu_addr, size) && __pu_addr) \
+ __put_user_size(__pu_val, __pu_addr, (size), __pu_err); \
+ __pu_err; \
+})
+
+#define __put_user_size(x, ptr, size, retval) \
+do { \
+ retval = 0; \
+ switch (size) { \
+ case 1: \
+ __put_user_asm_b(x, ptr, retval); \
+ break; \
+ case 2: \
+ __put_user_asm_h(x, ptr, retval); \
+ break; \
+ case 4: \
+ __put_user_asm_w(x, ptr, retval); \
+ break; \
+ case 8: \
+ __put_user_asm_64(x, ptr, retval
