[S390] Make user-copy operations run-time configurable.
Introduces a struct uaccess_ops which allows setting user-copy
operations at run-time.
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c
new file mode 100644
index 0000000..9a4d4a2
--- /dev/null
+++ b/arch/s390/lib/uaccess_std.c
@@ -0,0 +1,340 @@
+/*
+ * arch/s390/lib/uaccess_std.c
+ *
+ * Standard user space access functions based on mvcp/mvcs and doing
+ * interesting things in the secondary space mode.
+ *
+ * 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
+
+size_t copy_from_user_std(size_t size, const void __user *ptr, void *x)
+{
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -256UL;
+ asm volatile(
+ "0: mvcp 0(%0,%2),0(%1),%3\n"
+ " jz 5f\n"
+ "1:"ALR" %0,%3\n"
+ " la %1,256(%1)\n"
+ " la %2,256(%2)\n"
+ "2: mvcp 0(%0,%2),0(%1),%3\n"
+ " jnz 1b\n"
+ " j 5f\n"
+ "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
+ " "LHI" %3,-4096\n"
+ " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
+ " "SLR" %4,%1\n"
+ " "CLR" %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 6f\n"
+ "4: mvcp 0(%4,%2),0(%1),%3\n"
+ " "SLR" %0,%4\n"
+ " j 6f\n"
+ "5:"SLR" %0,%0\n"
+ "6: \n"
+ EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
+ : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+ : : "cc", "memory");
+ return size;
+}
+
+size_t copy_from_user_std_small(size_t size, const void __user *ptr, void *x)
+{
+ unsigned long tmp1, tmp2;
+
+ tmp1 = 0UL;
+ asm volatile(
+ "0: mvcp 0(%0,%2),0(%1),%3\n"
+ " "SLR" %0,%0\n"
+ " j 3f\n"
+ "1: la %4,255(%1)\n" /* %4 = ptr + 255 */
+ " "LHI" %3,-4096\n"
+ " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
+ " "SLR" %4,%1\n"
+ " "CLR" %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 3f\n"
+ "2: mvcp 0(%4,%2),0(%1),%3\n"
+ " "SLR" %0,%4\n"
+ "3:\n"
+ EX_TABLE(0b,1b) EX_TABLE(2b,3b)
+ : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+ : : "cc", "memory");
+ return size;
+}
+
+size_t copy_to_user_std(size_t size, void __user *ptr, const void *x)
+{
+ unsigned long tmp1, tmp2;
+
+ tmp1 = -256UL;
+ asm volatile(
+ "0: mvcs 0(%0,%1),0(%2),%3\n"
+ " jz 5f\n"
+ "1:"ALR" %0,%3\n"
+ " la %1,256(%1)\n"
+ " la %2,256(%2)\n"
+ "2: mvcs 0(%0,%1),0(%2),%3\n"
+ " jnz 1b\n"
+ " j 5f\n"
+ "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
+ " "LHI" %3,-4096\n"
+ " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
+ " "SLR" %4,%1\n"
+ " "CLR" %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 6f\n"
+ "4: mvcs 0(%4,%1),0(%2),%3\n"
+ " "SLR" %0,%4\n"
+ " j 6f\n"
+ "5:"SLR" %0,%0\n"
+ "6: \n"
+ EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
+ : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+ : : "cc", "memory");
+ return size;
+}
+
+size_t copy_to_user_std_small(size_t size, void __user *ptr, const void *x)
+{
+ unsigned long tmp1, tmp2;
+
+ tmp1 = 0UL;
+ asm volatile(
+ "0: mvcs 0(%0,%1),0(%2),%3\n"
+ " "SLR" %0,%0\n"
+ " j 3f\n"
+ "1: la %4,255(%1)\n" /* ptr + 255 */
+ " "LHI" %3,-4096\n"
+ " nr %4,%3\n" /* (ptr + 255) & -4096UL */
+ " "SLR" %4,%1\n"
+ " "CLR" %0,%4\n" /* copy crosses next page boundary? */
+ " jnh 3f\n"
+ "2: mvcs 0(%4,%1),0(%2),%3\n"
+ " "SLR" %0,%4\n"
+ "3:\n"
+ EX_TABLE(0b,1b) EX_TABLE(2b,3b)
+ : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
+ : : "cc", "memory");
+ return size;
+}
+
+size_t copy_in_user_std(size_t size, void __user *to, const void __user *from)
+{
+ unsigned long tmp1;
+
+ asm volatile(
+ " "AHI" %0,-1\n"
+ " jo 5f\n"
+ " sacf 256\n"
+ " bras %3,3f\n"
+ "0:"AHI" %0,257\n"
+ "1: mvc 0(1,%1),0(%2)\n"
+ " la %1,1(%1)\n"
+ " la %2,1(%2)\n"
+ " "AHI" %0,-1\n"
+ " jnz 1b\n"
+ " j 5f\n"
+ "2: mvc 0(256,%1),0(%2)\n"
+ " la %1,256(%1)\n"
+ " la %2,256(%2)\n"
+ "3:"AHI" %0,-256\n"
+ " jnm 2b\n"
+ "4: ex %0,1b-0b(%3)\n"
+ " sacf 0\n"
+ "5: "SLR" %0,%0\n"
+ "6:\n"
+ EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
+ : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
+ : : "cc", "memory");
+ return size;
+}
+
+size_t clear_user_std(size_t size, void __user *to)
+{
+ unsigned long tmp1, tmp2;
+
+ asm volatile(
+ " "AHI" %0,-1\n"
+ " jo 5f\n"
+ " sacf 256\n"
+ " bras %3,3f\n"
+ " xc 0(1,%1),0(%1)\n"
+ "0:"AHI" %0,257\n"
+ " la %2,255(%1)\n" /* %2 = ptr + 255 */
+ " srl %2,12\n"
+ " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
+ " "SLR" %2,%1\n"
+ " "CLR" %0,%2\n" /* clear crosses next page boundary? */
+ " jnh 5f\n"
+ " "AHI" %2,-1\n"
+ "1: ex %2,0(%3)\n"
+ " "AHI" %2,1\n"
+ " "SLR" %0,%2\n"
+ " j 5f\n"
+ "2: xc 0(256,%1),0(%1)\n"
+ " la %1,256(%1)\n"
+ "3:"AHI" %0,-256\n"
+ " jnm 2b\n"
+ "4: ex %0,0(%3)\n"
+ " sacf 0\n"
+ "5: "SLR" %0,%0\n"
+ "6:\n"
+ EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
+ : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
+ : : "cc", "memory");
+ return size;
+}
+
+size_t strnlen_user_std(size_t size, const char __user *src)
+{
+ register unsigned long reg0 asm("0") = 0UL;
+ unsigned long tmp1, tmp2;
+
+ asm volatile(
+ " la %2,0(%1)\n"
+ " la %3,0(%0,%1)\n"
+ " "SLR" %0,%0\n"
+ " sacf 256\n"
+ "0: srst %3,%2\n"
+ " jo 0b\n"
+ " la %0,1(%3)\n" /* strnlen_user results includes \0 */
+ " "SLR" %0,%1\n"
+ "1: sacf 0\n"
+ EX_TABLE(0b,1b)
+ : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
+ : "d" (reg0) : "cc", "memory");
+ return size;
+}
+
+size_t strncpy_from_user_std(size_t size, const char __user *src, char *dst)
+{
+ register unsigned long reg0 asm("0") = 0UL;
+ unsigned long tmp1, tmp2;
+
+ asm volatile(
+ " la %3,0(%1)\n"
+ " la %4,0(%0,%1)\n"
+ " sacf 256\n"
+ "0: srst %4,%3\n"
+ " jo 0b\n"
+ " sacf 0\n"
+ " la %0,0(%4)\n"
+ " jh 1f\n" /* found \0 in string ? */
+ " "AHI" %4,1\n" /* include \0 in copy */
+ "1:"SLR" %0,%1\n" /* %0 = return length (without \0) */
+ " "SLR" %4,%1\n" /* %4 = copy length (including \0) */
+ "2: mvcp 0(%4,%2),0(%1),%5\n"
+ " jz 9f\n"
+ "3:"AHI" %4,-256\n"
+ " la %1,256(%1)\n"
+ " la %2,256(%2)\n"
+ "4: mvcp 0(%4,%2),0(%1),%5\n"
+ " jnz 3b\n"
+ " j 9f\n"
+ "7: sacf 0\n"
+ "8:"LHI" %0,%6\n"
+ "9:\n"
+ EX_TABLE(0b,7b) EX_TABLE(2b,8b) EX_TABLE(4b,8b)
+ : "+a" (size), "+a" (src), "+d" (dst), "=a" (tmp1), "=a" (tmp2)
+ : "d" (reg0), "K" (-EFAULT) : "cc", "memory");
+ return size;
+}
+
+#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \
+ asm volatile( \
+ " sacf 256\n" \
+ "0: l %1,0(%6)\n" \
+ "1:"insn \
+ "2: cs %1,%2,0(%6)\n" \
+ "3: jl 1b\n" \
+ " lhi %0,0\n" \
+ "4: sacf 0\n" \
+ EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b) \
+ : "=d" (ret), "=&d" (oldval), "=&d" (newval), \
+ "=m" (*uaddr) \
+ : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \
+ "m" (*uaddr) : "cc");
+
+int futex_atomic_op(int op, int __user *uaddr, int oparg, int *old)
+{
+ int oldval = 0, newval, ret;
+
+ inc_preempt_count();
+
+ switch (op) {
+ case FUTEX_OP_SET:
+ __futex_atomic_op("lr %2,%5\n",
+ ret, oldval, newval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD:
+ __futex_atomic_op("lr %2,%1\nar %2,%5\n",
+ ret, oldval, newval, uaddr, oparg);
+ break;
+ case FUTEX_OP_OR:
+ __futex_atomic_op("lr %2,%1\nor %2,%5\n",
+ ret, oldval, newval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN:
+ __futex_atomic_op("lr %2,%1\nnr %2,%5\n",
+ ret, oldval, newval, uaddr, oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("lr %2,%1\nxr %2,%5\n",
+ ret, oldval, newval, uaddr, oparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+ dec_preempt_count();
+ *old = oldval;
+ return ret;
+}
+
+int futex_atomic_cmpxchg(int __user *uaddr, int oldval, int newval)
+{
+ int ret;
+
+ asm volatile(
+ " sacf 256\n"
+ " cs %1,%4,0(%5)\n"
+ "0: lr %0,%1\n"
+ "1: sacf 0\n"
+ EX_TABLE(0b,1b)
+ : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
+ : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
+ : "cc", "memory" );
+ return ret;
+}
+
+struct uaccess_ops uaccess_std = {
+ .copy_from_user = copy_from_user_std,
+ .copy_from_user_small = copy_from_user_std_small,
+ .copy_to_user = copy_to_user_std,
+ .copy_to_user_small = copy_to_user_std_small,
+ .copy_in_user = copy_in_user_std,
+ .clear_user = clear_user_std,
+ .strnlen_user = strnlen_user_std,
+ .strncpy_from_user = strncpy_from_user_std,
+ .futex_atomic_op = futex_atomic_op,
+ .futex_atomic_cmpxchg = futex_atomic_cmpxchg,
+};