[deliverable/linux.git] / arch / s390 / lib / uaccess.c

/*
 *  Standard user space access functions based on mvcp/mvcs and doing
 *  interesting things in the secondary space mode.
 *
 *    Copyright IBM Corp. 2006,2014
 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
 *		 Gerald Schaefer (gerald.schaefer@de.ibm.com)
 */

#include <linux/jump_label.h>
#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <asm/mmu_context.h>
#include <asm/facility.h>

static DEFINE_STATIC_KEY_FALSE(have_mvcos);

static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
						 unsigned long size)
{
	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"
		"9: jz    7f\n"
		"1: algr  %0,%3\n"
		"   slgr  %1,%3\n"
		"   slgr  %2,%3\n"
		"   j     0b\n"
		"2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
		"   slgr  %4,%1\n"
		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
		"   jnh   4f\n"
		"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
		"10:slgr  %0,%4\n"
		"   algr  %2,%4\n"
		"4: lghi  %4,-1\n"
		"   algr  %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: aghi  %4,-256\n"
		"   jnm   5b\n"
		"   ex    %4,0(%3)\n"
		"   j     8f\n"
		"7: slgr  %0,%0\n"
		"8:\n"
		EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
		: "d" (reg0) : "cc", "memory");
	return size;
}

static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
						unsigned long size)
{
	unsigned long tmp1, tmp2;

	load_kernel_asce();
	tmp1 = -256UL;
	asm volatile(
		"   sacf  0\n"
		"0: mvcp  0(%0,%2),0(%1),%3\n"
		"10:jz    8f\n"
		"1: algr  %0,%3\n"
		"   la    %1,256(%1)\n"
		"   la    %2,256(%2)\n"
		"2: mvcp  0(%0,%2),0(%1),%3\n"
		"11:jnz   1b\n"
		"   j     8f\n"
		"3: la    %4,255(%1)\n"	/* %4 = ptr + 255 */
		"   lghi  %3,-4096\n"
		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
		"   slgr  %4,%1\n"
		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
		"   jnh   5f\n"
		"4: mvcp  0(%4,%2),0(%1),%3\n"
		"12:slgr  %0,%4\n"
		"   algr  %2,%4\n"
		"5: lghi  %4,-1\n"
		"   algr  %4,%0\n"	/* copy remaining size, subtract 1 */
		"   bras  %3,7f\n"	/* memset loop */
		"   xc    0(1,%2),0(%2)\n"
		"6: xc    0(256,%2),0(%2)\n"
		"   la    %2,256(%2)\n"
		"7: aghi  %4,-256\n"
		"   jnm   6b\n"
		"   ex    %4,0(%3)\n"
		"   j     9f\n"
		"8: slgr  %0,%0\n"
		"9: sacf  768\n"
		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
		EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
		: : "cc", "memory");
	return size;
}

unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
{
	if (static_branch_likely(&have_mvcos))
		return copy_from_user_mvcos(to, from, n);
	return copy_from_user_mvcp(to, from, n);
}
EXPORT_SYMBOL(__copy_from_user);

static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
					       unsigned long size)
{
	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"
		"6: jz    4f\n"
		"1: algr  %0,%3\n"
		"   slgr  %1,%3\n"
		"   slgr  %2,%3\n"
		"   j     0b\n"
		"2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
		"   slgr  %4,%1\n"
		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
		"   jnh   5f\n"
		"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
		"7: slgr  %0,%4\n"
		"   j     5f\n"
		"4: slgr  %0,%0\n"
		"5:\n"
		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
		: "d" (reg0) : "cc", "memory");
	return size;
}

static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
					      unsigned long size)
{
	unsigned long tmp1, tmp2;

	load_kernel_asce();
	tmp1 = -256UL;
	asm volatile(
		"   sacf  0\n"
		"0: mvcs  0(%0,%1),0(%2),%3\n"
		"7: jz    5f\n"
		"1: algr  %0,%3\n"
		"   la    %1,256(%1)\n"
		"   la    %2,256(%2)\n"
		"2: mvcs  0(%0,%1),0(%2),%3\n"
		"8: jnz   1b\n"
		"   j     5f\n"
		"3: la    %4,255(%1)\n" /* %4 = ptr + 255 */
		"   lghi  %3,-4096\n"
		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
		"   slgr  %4,%1\n"
		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
		"   jnh   6f\n"
		"4: mvcs  0(%4,%1),0(%2),%3\n"
		"9: slgr  %0,%4\n"
		"   j     6f\n"
		"5: slgr  %0,%0\n"
		"6: sacf  768\n"
		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
		: : "cc", "memory");
	return size;
}

unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
{
	if (static_branch_likely(&have_mvcos))
		return copy_to_user_mvcos(to, from, n);
	return copy_to_user_mvcs(to, from, n);
}
EXPORT_SYMBOL(__copy_to_user);

static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
					       unsigned long size)
{
	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: algr  %0,%3\n"
		"   slgr  %1,%3\n"
		"   slgr  %2,%3\n"
		"   j	  0b\n"
		"2:slgr  %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;
}

static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
					     unsigned long size)
{
	unsigned long tmp1;

	load_kernel_asce();
	asm volatile(
		"   sacf  256\n"
		"   aghi  %0,-1\n"
		"   jo	  5f\n"
		"   bras  %3,3f\n"
		"0: aghi  %0,257\n"
		"1: mvc	  0(1,%1),0(%2)\n"
		"   la	  %1,1(%1)\n"
		"   la	  %2,1(%2)\n"
		"   aghi  %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: aghi  %0,-256\n"
		"   jnm	  2b\n"
		"4: ex	  %0,1b-0b(%3)\n"
		"5: slgr  %0,%0\n"
		"6: sacf  768\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;
}

unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
	if (static_branch_likely(&have_mvcos))
		return copy_in_user_mvcos(to, from, n);
	return copy_in_user_mvc(to, from, n);
}
EXPORT_SYMBOL(__copy_in_user);

static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
{
	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: algr  %0,%2\n"
		"   slgr  %1,%2\n"
		"   j	  0b\n"
		"2: la	  %3,4095(%1)\n"/* %4 = to + 4095 */
		"   nr	  %3,%2\n"	/* %4 = (to + 4095) & -4096 */
		"   slgr  %3,%1\n"
		"   clgr  %0,%3\n"	/* copy crosses next page boundary? */
		"   jnh	  5f\n"
		"3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
		"   slgr  %0,%3\n"
		"   j	  5f\n"
		"4: slgr  %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;
}

static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
{
	unsigned long tmp1, tmp2;

	load_kernel_asce();
	asm volatile(
		"   sacf  256\n"
		"   aghi  %0,-1\n"
		"   jo    5f\n"
		"   bras  %3,3f\n"
		"   xc    0(1,%1),0(%1)\n"
		"0: aghi  %0,257\n"
		"   la    %2,255(%1)\n" /* %2 = ptr + 255 */
		"   srl   %2,12\n"
		"   sll   %2,12\n"	/* %2 = (ptr + 255) & -4096 */
		"   slgr  %2,%1\n"
		"   clgr  %0,%2\n"	/* clear crosses next page boundary? */
		"   jnh   5f\n"
		"   aghi  %2,-1\n"
		"1: ex    %2,0(%3)\n"
		"   aghi  %2,1\n"
		"   slgr  %0,%2\n"
		"   j     5f\n"
		"2: xc    0(256,%1),0(%1)\n"
		"   la    %1,256(%1)\n"
		"3: aghi  %0,-256\n"
		"   jnm   2b\n"
		"4: ex    %0,0(%3)\n"
		"5: slgr  %0,%0\n"
		"6: sacf  768\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;
}

unsigned long __clear_user(void __user *to, unsigned long size)
{
	if (static_branch_likely(&have_mvcos))
			return clear_user_mvcos(to, size);
	return clear_user_xc(to, size);
}
EXPORT_SYMBOL(__clear_user);

static inline unsigned long strnlen_user_srst(const char __user *src,
					      unsigned long size)
{
	register unsigned long reg0 asm("0") = 0;
	unsigned long tmp1, tmp2;

	asm volatile(
		"   la    %2,0(%1)\n"
		"   la    %3,0(%0,%1)\n"
		"   slgr  %0,%0\n"
		"   sacf  256\n"
		"0: srst  %3,%2\n"
		"   jo    0b\n"
		"   la    %0,1(%3)\n"	/* strnlen_user results includes \0 */
		"   slgr  %0,%1\n"
		"1: sacf  768\n"
		EX_TABLE(0b,1b)
		: "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
		: "d" (reg0) : "cc", "memory");
	return size;
}

unsigned long __strnlen_user(const char __user *src, unsigned long size)
{
	if (unlikely(!size))
		return 0;
	load_kernel_asce();
	return strnlen_user_srst(src, size);
}
EXPORT_SYMBOL(__strnlen_user);

long __strncpy_from_user(char *dst, const char __user *src, long size)
{
	size_t done, len, offset, len_str;

	if (unlikely(size <= 0))
		return 0;
	done = 0;
	do {
		offset = (size_t)src & ~PAGE_MASK;
		len = min(size - done, PAGE_SIZE - offset);
		if (copy_from_user(dst, src, len))
			return -EFAULT;
		len_str = strnlen(dst, len);
		done += len_str;
		src += len_str;
		dst += len_str;
	} while ((len_str == len) && (done < size));
	return done;
}
EXPORT_SYMBOL(__strncpy_from_user);

static int __init uaccess_init(void)
{
	if (test_facility(27))
		static_branch_enable(&have_mvcos);
	return 0;
}
early_initcall(uaccess_init);
Commit	Line	Data
457f2180 HC	1	/*
	2	* Standard user space access functions based on mvcp/mvcs and doing
	3	* interesting things in the secondary space mode.
	4	*
	5	* Copyright IBM Corp. 2006,2014
	6	* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
	7	* Gerald Schaefer (gerald.schaefer@de.ibm.com)
	8	*/
	9
	10	#include <linux/jump_label.h>
	11	#include <linux/uaccess.h>
	12	#include <linux/export.h>
	13	#include <linux/errno.h>
	14	#include <linux/mm.h>
	15	#include <asm/mmu_context.h>
	16	#include <asm/facility.h>
	17
ed79e946	18	static DEFINE_STATIC_KEY_FALSE(have_mvcos);
457f2180 HC	19
	20	static inline unsigned long copy_from_user_mvcos(void x, const void __user ptr,
	21	unsigned long size)
	22	{
	23	register unsigned long reg0 asm("0") = 0x81UL;
	24	unsigned long tmp1, tmp2;
	25
	26	tmp1 = -4096UL;
	27	asm volatile(
	28	"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
	29	"9: jz 7f\n"
5a79859a HC	30	"1: algr %0,%3\n"
	31	" slgr %1,%3\n"
	32	" slgr %2,%3\n"
457f2180 HC	33	" j 0b\n"
	34	"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
	35	" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
5a79859a HC	36	" slgr %4,%1\n"
5a79859a HC	37	" clgr %0,%4\n" /* copy crosses next page boundary? */
457f2180 HC	38	" jnh 4f\n"
457f2180 HC	39	"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
5a79859a HC	40	"10:slgr %0,%4\n"
	41	" algr %2,%4\n"
	42	"4: lghi %4,-1\n"
	43	" algr %4,%0\n" /* copy remaining size, subtract 1 */
457f2180 HC	44	" bras %3,6f\n" /* memset loop */
	45	" xc 0(1,%2),0(%2)\n"
	46	"5: xc 0(256,%2),0(%2)\n"
	47	" la %2,256(%2)\n"
5a79859a	48	"6: aghi %4,-256\n"
457f2180 HC	49	" jnm 5b\n"
	50	" ex %4,0(%3)\n"
	51	" j 8f\n"
b8ac5e2f	52	"7: slgr %0,%0\n"
457f2180 HC	53	"8:\n"
	54	EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
	55	: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
	56	: "d" (reg0) : "cc", "memory");
	57	return size;
	58	}
	59
	60	static inline unsigned long copy_from_user_mvcp(void x, const void __user ptr,
	61	unsigned long size)
	62	{
	63	unsigned long tmp1, tmp2;
	64
beef560b	65	load_kernel_asce();
457f2180 HC	66	tmp1 = -256UL;
	67	asm volatile(
	68	" sacf 0\n"
	69	"0: mvcp 0(%0,%2),0(%1),%3\n"
	70	"10:jz 8f\n"
5a79859a	71	"1: algr %0,%3\n"
457f2180 HC	72	" la %1,256(%1)\n"
	73	" la %2,256(%2)\n"
	74	"2: mvcp 0(%0,%2),0(%1),%3\n"
	75	"11:jnz 1b\n"
	76	" j 8f\n"
	77	"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
5a79859a	78	" lghi %3,-4096\n"
457f2180	79	" nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
5a79859a HC	80	" slgr %4,%1\n"
5a79859a HC	81	" clgr %0,%4\n" /* copy crosses next page boundary? */
457f2180 HC	82	" jnh 5f\n"
457f2180 HC	83	"4: mvcp 0(%4,%2),0(%1),%3\n"
5a79859a HC	84	"12:slgr %0,%4\n"
	85	" algr %2,%4\n"
	86	"5: lghi %4,-1\n"
	87	" algr %4,%0\n" /* copy remaining size, subtract 1 */
457f2180 HC	88	" bras %3,7f\n" /* memset loop */
	89	" xc 0(1,%2),0(%2)\n"
	90	"6: xc 0(256,%2),0(%2)\n"
	91	" la %2,256(%2)\n"
5a79859a	92	"7: aghi %4,-256\n"
457f2180 HC	93	" jnm 6b\n"
	94	" ex %4,0(%3)\n"
	95	" j 9f\n"
b8ac5e2f	96	"8: slgr %0,%0\n"
457f2180 HC	97	"9: sacf 768\n"
	98	EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
	99	EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
	100	: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
	101	: : "cc", "memory");
	102	return size;
	103	}
	104
	105	unsigned long __copy_from_user(void to, const void __user from, unsigned long n)
	106	{
ed79e946	107	if (static_branch_likely(&have_mvcos))
457f2180 HC	108	return copy_from_user_mvcos(to, from, n);
	109	return copy_from_user_mvcp(to, from, n);
	110	}
	111	EXPORT_SYMBOL(__copy_from_user);
	112
	113	static inline unsigned long copy_to_user_mvcos(void __user ptr, const void x,
	114	unsigned long size)
	115	{
	116	register unsigned long reg0 asm("0") = 0x810000UL;
	117	unsigned long tmp1, tmp2;
	118
	119	tmp1 = -4096UL;
	120	asm volatile(
	121	"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
	122	"6: jz 4f\n"
5a79859a HC	123	"1: algr %0,%3\n"
	124	" slgr %1,%3\n"
	125	" slgr %2,%3\n"
457f2180 HC	126	" j 0b\n"
	127	"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
	128	" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
5a79859a HC	129	" slgr %4,%1\n"
5a79859a HC	130	" clgr %0,%4\n" /* copy crosses next page boundary? */
457f2180 HC	131	" jnh 5f\n"
457f2180 HC	132	"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
5a79859a	133	"7: slgr %0,%4\n"
457f2180	134	" j 5f\n"
5a79859a	135	"4: slgr %0,%0\n"
457f2180 HC	136	"5:\n"
	137	EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
	138	: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
	139	: "d" (reg0) : "cc", "memory");
	140	return size;
	141	}
	142
	143	static inline unsigned long copy_to_user_mvcs(void __user ptr, const void x,
	144	unsigned long size)
	145	{
	146	unsigned long tmp1, tmp2;
	147
beef560b	148	load_kernel_asce();
457f2180 HC	149	tmp1 = -256UL;
	150	asm volatile(
	151	" sacf 0\n"
	152	"0: mvcs 0(%0,%1),0(%2),%3\n"
	153	"7: jz 5f\n"
5a79859a	154	"1: algr %0,%3\n"
457f2180 HC	155	" la %1,256(%1)\n"
	156	" la %2,256(%2)\n"
	157	"2: mvcs 0(%0,%1),0(%2),%3\n"
	158	"8: jnz 1b\n"
	159	" j 5f\n"
	160	"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
5a79859a	161	" lghi %3,-4096\n"
457f2180	162	" nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
5a79859a HC	163	" slgr %4,%1\n"
5a79859a HC	164	" clgr %0,%4\n" /* copy crosses next page boundary? */
457f2180 HC	165	" jnh 6f\n"
457f2180 HC	166	"4: mvcs 0(%4,%1),0(%2),%3\n"
5a79859a	167	"9: slgr %0,%4\n"
457f2180	168	" j 6f\n"
5a79859a	169	"5: slgr %0,%0\n"
457f2180 HC	170	"6: sacf 768\n"
	171	EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
	172	EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
	173	: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
	174	: : "cc", "memory");
	175	return size;
	176	}
	177
	178	unsigned long __copy_to_user(void __user to, const void from, unsigned long n)
	179	{
ed79e946	180	if (static_branch_likely(&have_mvcos))
457f2180 HC	181	return copy_to_user_mvcos(to, from, n);
	182	return copy_to_user_mvcs(to, from, n);
	183	}
	184	EXPORT_SYMBOL(__copy_to_user);
	185
	186	static inline unsigned long copy_in_user_mvcos(void __user to, const void __user from,
	187	unsigned long size)
	188	{
	189	register unsigned long reg0 asm("0") = 0x810081UL;
	190	unsigned long tmp1, tmp2;
	191
	192	tmp1 = -4096UL;
	193	/* FIXME: copy with reduced length. */
	194	asm volatile(
	195	"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
	196	" jz 2f\n"
5a79859a HC	197	"1: algr %0,%3\n"
	198	" slgr %1,%3\n"
	199	" slgr %2,%3\n"
457f2180	200	" j 0b\n"
5a79859a	201	"2:slgr %0,%0\n"
457f2180 HC	202	"3: \n"
	203	EX_TABLE(0b,3b)
	204	: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
	205	: "d" (reg0) : "cc", "memory");
	206	return size;
	207	}
	208
	209	static inline unsigned long copy_in_user_mvc(void __user to, const void __user from,
	210	unsigned long size)
	211	{
	212	unsigned long tmp1;
	213
beef560b	214	load_kernel_asce();
457f2180 HC	215	asm volatile(
457f2180 HC	216	" sacf 256\n"
5a79859a	217	" aghi %0,-1\n"
457f2180 HC	218	" jo 5f\n"
457f2180 HC	219	" bras %3,3f\n"
5a79859a	220	"0: aghi %0,257\n"
457f2180 HC	221	"1: mvc 0(1,%1),0(%2)\n"
	222	" la %1,1(%1)\n"
	223	" la %2,1(%2)\n"
5a79859a	224	" aghi %0,-1\n"
457f2180 HC	225	" jnz 1b\n"
	226	" j 5f\n"
	227	"2: mvc 0(256,%1),0(%2)\n"
	228	" la %1,256(%1)\n"
	229	" la %2,256(%2)\n"
5a79859a	230	"3: aghi %0,-256\n"
457f2180 HC	231	" jnm 2b\n"
457f2180 HC	232	"4: ex %0,1b-0b(%3)\n"
5a79859a	233	"5: slgr %0,%0\n"
457f2180 HC	234	"6: sacf 768\n"
	235	EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
	236	: "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
	237	: : "cc", "memory");
	238	return size;
	239	}
	240
	241	unsigned long __copy_in_user(void __user to, const void __user from, unsigned long n)
	242	{
ed79e946	243	if (static_branch_likely(&have_mvcos))
457f2180 HC	244	return copy_in_user_mvcos(to, from, n);
	245	return copy_in_user_mvc(to, from, n);
	246	}
	247	EXPORT_SYMBOL(__copy_in_user);
	248
	249	static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
	250	{
	251	register unsigned long reg0 asm("0") = 0x810000UL;
	252	unsigned long tmp1, tmp2;
	253
	254	tmp1 = -4096UL;
	255	asm volatile(
	256	"0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
	257	" jz 4f\n"
5a79859a HC	258	"1: algr %0,%2\n"
5a79859a HC	259	" slgr %1,%2\n"
457f2180 HC	260	" j 0b\n"
	261	"2: la %3,4095(%1)\n"/* %4 = to + 4095 */
	262	" nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
5a79859a HC	263	" slgr %3,%1\n"
5a79859a HC	264	" clgr %0,%3\n" /* copy crosses next page boundary? */
457f2180 HC	265	" jnh 5f\n"
457f2180 HC	266	"3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
5a79859a	267	" slgr %0,%3\n"
457f2180	268	" j 5f\n"
b8ac5e2f	269	"4: slgr %0,%0\n"
457f2180 HC	270	"5:\n"
	271	EX_TABLE(0b,2b) EX_TABLE(3b,5b)
	272	: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
	273	: "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
	274	return size;
	275	}
	276
	277	static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
	278	{
	279	unsigned long tmp1, tmp2;
	280
beef560b	281	load_kernel_asce();
457f2180 HC	282	asm volatile(
457f2180 HC	283	" sacf 256\n"
5a79859a	284	" aghi %0,-1\n"
457f2180 HC	285	" jo 5f\n"
	286	" bras %3,3f\n"
	287	" xc 0(1,%1),0(%1)\n"
5a79859a	288	"0: aghi %0,257\n"
457f2180 HC	289	" la %2,255(%1)\n" /* %2 = ptr + 255 */
	290	" srl %2,12\n"
	291	" sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
5a79859a HC	292	" slgr %2,%1\n"
5a79859a HC	293	" clgr %0,%2\n" /* clear crosses next page boundary? */
457f2180	294	" jnh 5f\n"
5a79859a	295	" aghi %2,-1\n"
457f2180	296	"1: ex %2,0(%3)\n"
5a79859a HC	297	" aghi %2,1\n"
5a79859a HC	298	" slgr %0,%2\n"
457f2180 HC	299	" j 5f\n"
	300	"2: xc 0(256,%1),0(%1)\n"
	301	" la %1,256(%1)\n"
5a79859a	302	"3: aghi %0,-256\n"
457f2180 HC	303	" jnm 2b\n"
457f2180 HC	304	"4: ex %0,0(%3)\n"
5a79859a	305	"5: slgr %0,%0\n"
457f2180 HC	306	"6: sacf 768\n"
	307	EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
	308	: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
	309	: : "cc", "memory");
	310	return size;
	311	}
	312
	313	unsigned long __clear_user(void __user *to, unsigned long size)
	314	{
ed79e946	315	if (static_branch_likely(&have_mvcos))
457f2180 HC	316	return clear_user_mvcos(to, size);
	317	return clear_user_xc(to, size);
	318	}
	319	EXPORT_SYMBOL(__clear_user);
	320
	321	static inline unsigned long strnlen_user_srst(const char __user *src,
	322	unsigned long size)
	323	{
	324	register unsigned long reg0 asm("0") = 0;
	325	unsigned long tmp1, tmp2;
	326
457f2180 HC	327	asm volatile(
	328	" la %2,0(%1)\n"
	329	" la %3,0(%0,%1)\n"
5a79859a	330	" slgr %0,%0\n"
457f2180 HC	331	" sacf 256\n"
	332	"0: srst %3,%2\n"
	333	" jo 0b\n"
	334	" la %0,1(%3)\n" /* strnlen_user results includes \0 */
5a79859a	335	" slgr %0,%1\n"
457f2180 HC	336	"1: sacf 768\n"
	337	EX_TABLE(0b,1b)
	338	: "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
	339	: "d" (reg0) : "cc", "memory");
	340	return size;
	341	}
	342
	343	unsigned long __strnlen_user(const char __user *src, unsigned long size)
	344	{
fa255f51 HC	345	if (unlikely(!size))
fa255f51 HC	346	return 0;
beef560b	347	load_kernel_asce();
457f2180 HC	348	return strnlen_user_srst(src, size);
	349	}
	350	EXPORT_SYMBOL(__strnlen_user);
	351
	352	long __strncpy_from_user(char dst, const char __user src, long size)
	353	{
	354	size_t done, len, offset, len_str;
	355
	356	if (unlikely(size <= 0))
	357	return 0;
	358	done = 0;
	359	do {
	360	offset = (size_t)src & ~PAGE_MASK;
	361	len = min(size - done, PAGE_SIZE - offset);
	362	if (copy_from_user(dst, src, len))
	363	return -EFAULT;
	364	len_str = strnlen(dst, len);
	365	done += len_str;
	366	src += len_str;
	367	dst += len_str;
	368	} while ((len_str == len) && (done < size));
	369	return done;
	370	}
	371	EXPORT_SYMBOL(__strncpy_from_user);
	372
457f2180 HC	373	static int __init uaccess_init(void)
457f2180 HC	374	{
cabc4abe	375	if (test_facility(27))
ed79e946	376	static_branch_enable(&have_mvcos);
457f2180 HC	377	return 0;
	378	}
	379	early_initcall(uaccess_init);