1 files changed, 121 insertions, 0 deletions
diff --git a/arch/alpha/lib/copy_user.S b/arch/alpha/lib/copy_user.S
new file mode 100644
index 000000000..32ab0344b
--- /dev/null
+++ b/arch/alpha/lib/copy_user.S
@@ -0,0 +1,121 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * arch/alpha/lib/copy_user.S
+ *
+ * Copy to/from user space, handling exceptions as we go..  This
+ * isn't exactly pretty.
+ *
+ * This is essentially the same as "memcpy()", but with a few twists.
+ * Notably, we have to make sure that $0 is always up-to-date and
+ * contains the right "bytes left to copy" value (and that it is updated
+ * only _after_ a successful copy). There is also some rather minor
+ * exception setup stuff..
+ */
+
+#include <asm/export.h>
+
+/* Allow an exception for an insn; exit if we get one.  */
+#define EXI(x,y...)			\
+	99: x,##y;			\
+	.section __ex_table,"a";	\
+	.long 99b - .;			\
+	lda $31, $exitin-99b($31);	\
+	.previous
+
+#define EXO(x,y...)			\
+	99: x,##y;			\
+	.section __ex_table,"a";	\
+	.long 99b - .;			\
+	lda $31, $exitout-99b($31);	\
+	.previous
+
+	.set noat
+	.align 4
+	.globl __copy_user
+	.ent __copy_user
+__copy_user:
+	.prologue 0
+	mov $18,$0
+	and $16,7,$3
+	beq $0,$35
+	beq $3,$36
+	subq $3,8,$3
+	.align 4
+$37:
+	EXI( ldq_u $1,0($17) )
+	EXO( ldq_u $2,0($16) )
+	extbl $1,$17,$1
+	mskbl $2,$16,$2
+	insbl $1,$16,$1
+	addq $3,1,$3
+	bis $1,$2,$1
+	EXO( stq_u $1,0($16) )
+	subq $0,1,$0
+	addq $16,1,$16
+	addq $17,1,$17
+	beq $0,$41
+	bne $3,$37
+$36:
+	and $17,7,$1
+	bic $0,7,$4
+	beq $1,$43
+	beq $4,$48
+	EXI( ldq_u $3,0($17) )
+	.align 4
+$50:
+	EXI( ldq_u $2,8($17) )
+	subq $4,8,$4
+	extql $3,$17,$3
+	extqh $2,$17,$1
+	bis $3,$1,$1
+	EXO( stq $1,0($16) )
+	addq $17,8,$17
+	subq $0,8,$0
+	addq $16,8,$16
+	bis $2,$2,$3
+	bne $4,$50
+$48:
+	beq $0,$41
+	.align 4
+$57:
+	EXI( ldq_u $1,0($17) )
+	EXO( ldq_u $2,0($16) )
+	extbl $1,$17,$1
+	mskbl $2,$16,$2
+	insbl $1,$16,$1
+	bis $1,$2,$1
+	EXO( stq_u $1,0($16) )
+	subq $0,1,$0
+	addq $16,1,$16
+	addq $17,1,$17
+	bne $0,$57
+	br $31,$41
+	.align 4
+$43:
+	beq $4,$65
+	.align 4
+$66:
+	EXI( ldq $1,0($17) )
+	subq $4,8,$4
+	EXO( stq $1,0($16) )
+	addq $17,8,$17
+	subq $0,8,$0
+	addq $16,8,$16
+	bne $4,$66
+$65:
+	beq $0,$41
+	EXI( ldq $2,0($17) )
+	EXO( ldq $1,0($16) )
+	mskql $2,$0,$2
+	mskqh $1,$0,$1
+	bis $2,$1,$2
+	EXO( stq $2,0($16) )
+	bis $31,$31,$0
+$41:
+$35:
+$exitin:
+$exitout:
+	ret $31,($26),1
+
+	.end __copy_user
+EXPORT_SYMBOL(__copy_user)