1 files changed, 87 insertions, 0 deletions
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
new file mode 100644
index 000000000..7cd6eeaa2
--- /dev/null
+++ b/arch/arm64/lib/copy_from_user.S
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/cache.h>
+#include <asm/asm-uaccess.h>
+
+/*
+ * Copy from user space to a kernel buffer (alignment handled by the hardware)
+ *
+ * Parameters:
+ *	x0 - to
+ *	x1 - from
+ *	x2 - n
+ * Returns:
+ *	x0 - bytes not copied
+ */
+
+	.macro ldrb1 ptr, regB, val
+	uao_user_alternative 9998f, ldrb, ldtrb, \ptr, \regB, \val
+	.endm
+
+	.macro strb1 ptr, regB, val
+	strb \ptr, [\regB], \val
+	.endm
+
+	.macro ldrh1 ptr, regB, val
+	uao_user_alternative 9997f, ldrh, ldtrh, \ptr, \regB, \val
+	.endm
+
+	.macro strh1 ptr, regB, val
+	strh \ptr, [\regB], \val
+	.endm
+
+	.macro ldr1 ptr, regB, val
+	uao_user_alternative 9997f, ldr, ldtr, \ptr, \regB, \val
+	.endm
+
+	.macro str1 ptr, regB, val
+	str \ptr, [\regB], \val
+	.endm
+
+	.macro ldp1 ptr, regB, regC, val
+	uao_ldp 9997f, \ptr, \regB, \regC, \val
+	.endm
+
+	.macro stp1 ptr, regB, regC, val
+	stp \ptr, \regB, [\regC], \val
+	.endm
+
+end	.req	x5
+srcin	.req	x15
+ENTRY(__arch_copy_from_user)
+	uaccess_enable_not_uao x3, x4, x5
+	add	end, x0, x2
+	mov	srcin, x1
+#include "copy_template.S"
+	uaccess_disable_not_uao x3, x4
+	mov	x0, #0				// Nothing to copy
+	ret
+ENDPROC(__arch_copy_from_user)
+
+	.section .fixup,"ax"
+	.align	2
+9997:	cmp	dst, dstin
+	b.ne	9998f
+	// Before being absolutely sure we couldn't copy anything, try harder
+USER(9998f, ldtrb tmp1w, [srcin])
+	strb	tmp1w, [dst], #1
+9998:	sub	x0, end, dst			// bytes not copied
+	uaccess_disable_not_uao x3, x4
+	ret
+	.previous