MIPS: uaccess: Added __get/__put_kernel_nofault

Added __get/__put_kernel_nofault as preparation for removing
get/set_fs.

Signed-off-by: Thomas Bogendoerfer <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>

arch/mips/include/asm/uaccess.h

···
 	(val) = __gu_tmp.t;						\
 }
 
+#define HAVE_GET_KERNEL_NOFAULT
+
+#define __get_kernel_nofault(dst, src, type, err_label)			\
+do {									\
+	int __gu_err;							\
+									\
+	__get_kernel_common(*((type *)(dst)), sizeof(type),		\
+			    (__force type *)(src));			\
+	if (unlikely(__gu_err))						\
+		goto err_label;						\
+} while (0)
+
 #ifndef CONFIG_EVA
 #define __put_kernel_common(ptr, size) __put_user_common(ptr, size)
 #else
···
 }
 
 extern void __put_user_unknown(void);
+
+#define __put_kernel_nofault(dst, src, type, err_label)			\
+do {									\
+	type __pu_val;					\
+	int __pu_err = 0;						\
+									\
+	__pu_val = *(__force type *)(src);				\
+	__put_kernel_common(((type *)(dst)), sizeof(type));		\
+	if (unlikely(__pu_err))						\
+		goto err_label;						\
+} while (0)
+
 
 /*
  * We're generating jump to subroutines which will be outside the range of

arch/mips/mm/Makefile

···
 obj-y				+= uasm-mips.o
 endif
 
+ifndef CONFIG_EVA
+obj-y				+= maccess.o
+endif
+
 obj-$(CONFIG_32BIT)		+= ioremap.o pgtable-32.o
 obj-$(CONFIG_64BIT)		+= ioremap64.o pgtable-64.o
 obj-$(CONFIG_HIGHMEM)		+= highmem.o

arch/mips/mm/maccess.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/uaccess.h>
+#include <linux/kernel.h>
+
+bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+{
+	/* highest bit set means kernel space */
+	return (unsigned long)unsafe_src >> (BITS_PER_LONG - 1);
+}