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-rw-r--r--arch/s390/lib/uaccess64.S206
1 files changed, 206 insertions, 0 deletions
diff --git a/arch/s390/lib/uaccess64.S b/arch/s390/lib/uaccess64.S
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+/*
+ * arch/s390x/lib/uaccess.S
+ * __copy_{from|to}_user functions.
+ *
+ * s390
+ * Copyright (C) 2000,2002 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Authors(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ * These functions have standard call interface
+ */
+
+#include <linux/errno.h>
+#include <asm/lowcore.h>
+#include <asm/offsets.h>
+
+ .text
+ .align 4
+ .globl __copy_from_user_asm
+ # %r2 = to, %r3 = n, %r4 = from
+__copy_from_user_asm:
+ slgr %r0,%r0
+0: mvcp 0(%r3,%r2),0(%r4),%r0
+ jnz 1f
+ slgr %r2,%r2
+ br %r14
+1: la %r2,256(%r2)
+ la %r4,256(%r4)
+ aghi %r3,-256
+2: mvcp 0(%r3,%r2),0(%r4),%r0
+ jnz 1b
+3: slgr %r2,%r2
+ br %r14
+4: lghi %r0,-4096
+ lgr %r5,%r4
+ slgr %r5,%r0
+ ngr %r5,%r0 # %r5 = (%r4 + 4096) & -4096
+ slgr %r5,%r4 # %r5 = #bytes to next user page boundary
+ clgr %r3,%r5 # copy crosses next page boundary ?
+ jnh 6f # no, the current page faulted
+ # move with the reduced length which is < 256
+5: mvcp 0(%r5,%r2),0(%r4),%r0
+ slgr %r3,%r5
+6: lgr %r2,%r3
+ br %r14
+ .section __ex_table,"a"
+ .quad 0b,4b
+ .quad 2b,4b
+ .quad 5b,6b
+ .previous
+
+ .align 4
+ .text
+ .globl __copy_to_user_asm
+ # %r2 = from, %r3 = n, %r4 = to
+__copy_to_user_asm:
+ slgr %r0,%r0
+0: mvcs 0(%r3,%r4),0(%r2),%r0
+ jnz 1f
+ slgr %r2,%r2
+ br %r14
+1: la %r2,256(%r2)
+ la %r4,256(%r4)
+ aghi %r3,-256
+2: mvcs 0(%r3,%r4),0(%r2),%r0
+ jnz 1b
+3: slgr %r2,%r2
+ br %r14
+4: lghi %r0,-4096
+ lgr %r5,%r4
+ slgr %r5,%r0
+ ngr %r5,%r0 # %r5 = (%r4 + 4096) & -4096
+ slgr %r5,%r4 # %r5 = #bytes to next user page boundary
+ clgr %r3,%r5 # copy crosses next page boundary ?
+ jnh 6f # no, the current page faulted
+ # move with the reduced length which is < 256
+5: mvcs 0(%r5,%r4),0(%r2),%r0
+ slgr %r3,%r5
+6: lgr %r2,%r3
+ br %r14
+ .section __ex_table,"a"
+ .quad 0b,4b
+ .quad 2b,4b
+ .quad 5b,6b
+ .previous
+
+ .align 4
+ .text
+ .globl __copy_in_user_asm
+ # %r2 = from, %r3 = n, %r4 = to
+__copy_in_user_asm:
+ sacf 256
+ bras 1,1f
+ mvc 0(1,%r4),0(%r2)
+0: mvc 0(256,%r4),0(%r2)
+ la %r2,256(%r2)
+ la %r4,256(%r4)
+1: aghi %r3,-256
+ jnm 0b
+2: ex %r3,0(%r1)
+ sacf 0
+ slgr %r2,%r2
+ br 14
+3: mvc 0(1,%r4),0(%r2)
+ la %r2,1(%r2)
+ la %r4,1(%r4)
+ aghi %r3,-1
+ jnm 3b
+4: lgr %r2,%r3
+ sacf 0
+ br %r14
+ .section __ex_table,"a"
+ .quad 0b,3b
+ .quad 2b,3b
+ .quad 3b,4b
+ .previous
+
+ .align 4
+ .text
+ .globl __clear_user_asm
+ # %r2 = to, %r3 = n
+__clear_user_asm:
+ slgr %r0,%r0
+ larl %r5,empty_zero_page
+1: mvcs 0(%r3,%r2),0(%r5),%r0
+ jnz 2f
+ slgr %r2,%r2
+ br %r14
+2: la %r2,256(%r2)
+ aghi %r3,-256
+3: mvcs 0(%r3,%r2),0(%r5),%r0
+ jnz 2b
+4: slgr %r2,%r2
+ br %r14
+5: lghi %r0,-4096
+ lgr %r4,%r2
+ slgr %r4,%r0
+ ngr %r4,%r0 # %r4 = (%r2 + 4096) & -4096
+ slgr %r4,%r2 # %r4 = #bytes to next user page boundary
+ clgr %r3,%r4 # clear crosses next page boundary ?
+ jnh 7f # no, the current page faulted
+ # clear with the reduced length which is < 256
+6: mvcs 0(%r4,%r2),0(%r5),%r0
+ slgr %r3,%r4
+7: lgr %r2,%r3
+ br %r14
+ .section __ex_table,"a"
+ .quad 1b,5b
+ .quad 3b,5b
+ .quad 6b,7b
+ .previous
+
+ .align 4
+ .text
+ .globl __strncpy_from_user_asm
+ # %r2 = count, %r3 = dst, %r4 = src
+__strncpy_from_user_asm:
+ lghi %r0,0
+ lgr %r1,%r4
+ la %r2,0(%r2,%r4) # %r2 points to first byte after string
+ sacf 256
+0: srst %r2,%r1
+ jo 0b
+ sacf 0
+ lgr %r1,%r2
+ jh 1f # \0 found in string ?
+ aghi %r1,1 # include \0 in copy
+1: slgr %r1,%r4 # %r1 = copy length (without \0)
+ slgr %r2,%r4 # %r2 = return length (including \0)
+2: mvcp 0(%r1,%r3),0(%r4),%r0
+ jnz 3f
+ br %r14
+3: la %r3,256(%r3)
+ la %r4,256(%r4)
+ aghi %r1,-256
+ mvcp 0(%r1,%r3),0(%r4),%r0
+ jnz 3b
+ br %r14
+4: sacf 0
+ lghi %r2,-EFAULT
+ br %r14
+ .section __ex_table,"a"
+ .quad 0b,4b
+ .previous
+
+ .align 4
+ .text
+ .globl __strnlen_user_asm
+ # %r2 = count, %r3 = src
+__strnlen_user_asm:
+ lghi %r0,0
+ lgr %r1,%r3
+ la %r2,0(%r2,%r3) # %r2 points to first byte after string
+ sacf 256
+0: srst %r2,%r1
+ jo 0b
+ sacf 0
+ jh 1f # \0 found in string ?
+ aghi %r2,1 # strnlen_user result includes the \0
+1: slgr %r2,%r3
+ br %r14
+2: sacf 0
+ lghi %r2,-EFAULT
+ br %r14
+ .section __ex_table,"a"
+ .quad 0b,2b
+ .previous