--- /dev/null
+/*
+ * arch/s390/lib/uaccess_mvcos.c
+ *
+ * Optimized user space space access functions based on mvcos.
+ *
+ * Copyright (C) IBM Corp. 2006
+ * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
+ * Gerald Schaefer (gerald.schaefer@de.ibm.com)
+ */
+
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <asm/uaccess.h>
+#include <asm/futex.h>
+
+#ifndef __s390x__
+#define AHI "ahi"
+#define ALR "alr"
+#define CLR "clr"
+#define LHI "lhi"
+#define SLR "slr"
+#else
+#define AHI "aghi"
+#define ALR "algr"
+#define CLR "clgr"
+#define LHI "lghi"
+#define SLR "slgr"
+#endif
+
+extern size_t copy_from_user_std(size_t, const void __user *, void *);
+extern size_t copy_to_user_std(size_t, void __user *, const void *);
+
+size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
+{
+ register unsigned long reg0 asm("0") = 0x81UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
+ " jz 7f\n"
+ "1:"ALR" %0,%3\n"
+ " "SLR" %1,%3\n"
+ " "SLR" %2,%3\n"
+ " j 0b\n"
+ "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
+ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
+ " "SLR" %4,%1\n"
+ " "CLR" %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 4f\n"
+ "3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
+ " "SLR" %0,%4\n"
+ " "ALR" %2,%4\n"
+ "4:"LHI" %4,-1\n"
+ " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
+ " bras %3,6f\n" /* memset loop */
+ " xc 0(1,%2),0(%2)\n"
+ "5: xc 0(256,%2),0(%2)\n"
+ " la %2,256(%2)\n"
+ "6:"AHI" %4,-256\n"
+ " jnm 5b\n"
+ " ex %4,0(%3)\n"
+ " j 8f\n"
+ "7:"SLR" %0,%0\n"
+ "8: \n"
+ EX_TABLE(0b,2b) EX_TABLE(3b,4b)
+ : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+ : "d" (reg0) : "cc", "memory");
+ return size;
+}
+
+size_t copy_from_user_mvcos_check(size_t size, const void __user *ptr, void *x)
+{
+ if (size <= 256)
+ return copy_from_user_std(size, ptr, x);
+ return copy_from_user_mvcos(size, ptr, x);
+}
+
+size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
+{
+ register unsigned long reg0 asm("0") = 0x810000UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+ " jz 4f\n"
+ "1:"ALR" %0,%3\n"
+ " "SLR" %1,%3\n"
+ " "SLR" %2,%3\n"
+ " j 0b\n"
+ "2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
+ " nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
+ " "SLR" %4,%1\n"
+ " "CLR" %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 5f\n"
+ "3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
+ " "SLR" %0,%4\n"
+ " j 5f\n"
+ "4:"SLR" %0,%0\n"
+ "5: \n"
+ EX_TABLE(0b,2b) EX_TABLE(3b,5b)
+ : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+ : "d" (reg0) : "cc", "memory");
+ return size;
+}
+
+size_t copy_to_user_mvcos_check(size_t size, void __user *ptr, const void *x)
+{
+ if (size <= 256)
+ return copy_to_user_std(size, ptr, x);
+ return copy_to_user_mvcos(size, ptr, x);
+}
+
+size_t copy_in_user_mvcos(size_t size, void __user *to, const void __user *from)
+{
+ register unsigned long reg0 asm("0") = 0x810081UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ /* FIXME: copy with reduced length. */
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
+ " jz 2f\n"
+ "1:"ALR" %0,%3\n"
+ " "SLR" %1,%3\n"
+ " "SLR" %2,%3\n"
+ " j 0b\n"
+ "2:"SLR" %0,%0\n"
+ "3: \n"
+ EX_TABLE(0b,3b)
+ : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
+ : "d" (reg0) : "cc", "memory");
+ return size;
+}
+
+size_t clear_user_mvcos(size_t size, void __user *to)
+{
+ register unsigned long reg0 asm("0") = 0x810000UL;
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -4096UL;
+ asm volatile(
+ "0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
+ " jz 4f\n"
+ "1:"ALR" %0,%2\n"
+ " "SLR" %1,%2\n"
+ " j 0b\n"
+ "2: la %3,4095(%1)\n"/* %4 = to + 4095 */
+ " nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
+ " "SLR" %3,%1\n"
+ " "CLR" %0,%3\n" /* copy crosses next page boundary? */
+ " jnh 5f\n"
+ "3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
+ " "SLR" %0,%3\n"
+ " j 5f\n"
+ "4:"SLR" %0,%0\n"
+ "5: \n"
+ EX_TABLE(0b,2b) EX_TABLE(3b,5b)
+ : "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
+ : "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
+ return size;
+}
+
+extern size_t strnlen_user_std(size_t, const char __user *);
+extern size_t strncpy_from_user_std(size_t, const char __user *, char *);
+extern int futex_atomic_op(int, int __user *, int, int *);
+extern int futex_atomic_cmpxchg(int __user *, int, int);
+
+struct uaccess_ops uaccess_mvcos = {
+ .copy_from_user = copy_from_user_mvcos_check,
+ .copy_from_user_small = copy_from_user_std,
+ .copy_to_user = copy_to_user_mvcos_check,
+ .copy_to_user_small = copy_to_user_std,
+ .copy_in_user = copy_in_user_mvcos,
+ .clear_user = clear_user_mvcos,
+ .strnlen_user = strnlen_user_std,
+ .strncpy_from_user = strncpy_from_user_std,
+ .futex_atomic_op = futex_atomic_op,
+ .futex_atomic_cmpxchg = futex_atomic_cmpxchg,
+};
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