LoongArch: Add memory management

Add memory management support for LoongArch, including: cache and tlb
management, page fault handling and ioremap/mmap support.

Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/loongarch/mm/maccess.c b/arch/loongarch/mm/maccess.c
new file mode 100644
index 000000000000..58173842c6be
--- /dev/null
+++ b/arch/loongarch/mm/maccess.c
@@ -0,0 +1,10 @@
+// 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);
+}