[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)
{
	check_object_size(to, n, false);
	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)
{
	check_object_size(from, n, true);
	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	{
97433ea4	107	check_object_size(to, n, false);
ed79e946	108	if (static_branch_likely(&have_mvcos))
457f2180 HC	109	return copy_from_user_mvcos(to, from, n);
	110	return copy_from_user_mvcp(to, from, n);
	111	}
	112	EXPORT_SYMBOL(__copy_from_user);
	113
	114	static inline unsigned long copy_to_user_mvcos(void __user ptr, const void x,
	115	unsigned long size)
	116	{
	117	register unsigned long reg0 asm("0") = 0x810000UL;
	118	unsigned long tmp1, tmp2;
	119
	120	tmp1 = -4096UL;
	121	asm volatile(
	122	"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
	123	"6: jz 4f\n"
5a79859a HC	124	"1: algr %0,%3\n"
	125	" slgr %1,%3\n"
	126	" slgr %2,%3\n"
457f2180 HC	127	" j 0b\n"
	128	"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
	129	" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
5a79859a HC	130	" slgr %4,%1\n"
5a79859a HC	131	" clgr %0,%4\n" /* copy crosses next page boundary? */
457f2180 HC	132	" jnh 5f\n"
457f2180 HC	133	"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
5a79859a	134	"7: slgr %0,%4\n"
457f2180	135	" j 5f\n"
5a79859a	136	"4: slgr %0,%0\n"
457f2180 HC	137	"5:\n"
	138	EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
	139	: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
	140	: "d" (reg0) : "cc", "memory");
	141	return size;
	142	}
	143
	144	static inline unsigned long copy_to_user_mvcs(void __user ptr, const void x,
	145	unsigned long size)
	146	{
	147	unsigned long tmp1, tmp2;
	148
beef560b	149	load_kernel_asce();
457f2180 HC	150	tmp1 = -256UL;
	151	asm volatile(
	152	" sacf 0\n"
	153	"0: mvcs 0(%0,%1),0(%2),%3\n"
	154	"7: jz 5f\n"
5a79859a	155	"1: algr %0,%3\n"
457f2180 HC	156	" la %1,256(%1)\n"
	157	" la %2,256(%2)\n"
	158	"2: mvcs 0(%0,%1),0(%2),%3\n"
	159	"8: jnz 1b\n"
	160	" j 5f\n"
	161	"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
5a79859a	162	" lghi %3,-4096\n"
457f2180	163	" nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
5a79859a HC	164	" slgr %4,%1\n"
5a79859a HC	165	" clgr %0,%4\n" /* copy crosses next page boundary? */
457f2180 HC	166	" jnh 6f\n"
457f2180 HC	167	"4: mvcs 0(%4,%1),0(%2),%3\n"
5a79859a	168	"9: slgr %0,%4\n"
457f2180	169	" j 6f\n"
5a79859a	170	"5: slgr %0,%0\n"
457f2180 HC	171	"6: sacf 768\n"
	172	EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
	173	EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
	174	: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
	175	: : "cc", "memory");
	176	return size;
	177	}
	178
	179	unsigned long __copy_to_user(void __user to, const void from, unsigned long n)
	180	{
97433ea4	181	check_object_size(from, n, true);
ed79e946	182	if (static_branch_likely(&have_mvcos))
457f2180 HC	183	return copy_to_user_mvcos(to, from, n);
	184	return copy_to_user_mvcs(to, from, n);
	185	}
	186	EXPORT_SYMBOL(__copy_to_user);
	187
	188	static inline unsigned long copy_in_user_mvcos(void __user to, const void __user from,
	189	unsigned long size)
	190	{
	191	register unsigned long reg0 asm("0") = 0x810081UL;
	192	unsigned long tmp1, tmp2;
	193
	194	tmp1 = -4096UL;
	195	/* FIXME: copy with reduced length. */
	196	asm volatile(
	197	"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
	198	" jz 2f\n"
5a79859a HC	199	"1: algr %0,%3\n"
	200	" slgr %1,%3\n"
	201	" slgr %2,%3\n"
457f2180	202	" j 0b\n"
5a79859a	203	"2:slgr %0,%0\n"
457f2180 HC	204	"3: \n"
	205	EX_TABLE(0b,3b)
	206	: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
	207	: "d" (reg0) : "cc", "memory");
	208	return size;
	209	}
	210
	211	static inline unsigned long copy_in_user_mvc(void __user to, const void __user from,
	212	unsigned long size)
	213	{
	214	unsigned long tmp1;
	215
beef560b	216	load_kernel_asce();
457f2180 HC	217	asm volatile(
457f2180 HC	218	" sacf 256\n"
5a79859a	219	" aghi %0,-1\n"
457f2180 HC	220	" jo 5f\n"
457f2180 HC	221	" bras %3,3f\n"
5a79859a	222	"0: aghi %0,257\n"
457f2180 HC	223	"1: mvc 0(1,%1),0(%2)\n"
	224	" la %1,1(%1)\n"
	225	" la %2,1(%2)\n"
5a79859a	226	" aghi %0,-1\n"
457f2180 HC	227	" jnz 1b\n"
	228	" j 5f\n"
	229	"2: mvc 0(256,%1),0(%2)\n"
	230	" la %1,256(%1)\n"
	231	" la %2,256(%2)\n"
5a79859a	232	"3: aghi %0,-256\n"
457f2180 HC	233	" jnm 2b\n"
457f2180 HC	234	"4: ex %0,1b-0b(%3)\n"
5a79859a	235	"5: slgr %0,%0\n"
457f2180 HC	236	"6: sacf 768\n"
	237	EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
	238	: "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
	239	: : "cc", "memory");
	240	return size;
	241	}
	242
	243	unsigned long __copy_in_user(void __user to, const void __user from, unsigned long n)
	244	{
ed79e946	245	if (static_branch_likely(&have_mvcos))
457f2180 HC	246	return copy_in_user_mvcos(to, from, n);
	247	return copy_in_user_mvc(to, from, n);
	248	}
	249	EXPORT_SYMBOL(__copy_in_user);
	250
	251	static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
	252	{
	253	register unsigned long reg0 asm("0") = 0x810000UL;
	254	unsigned long tmp1, tmp2;
	255
	256	tmp1 = -4096UL;
	257	asm volatile(
	258	"0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
	259	" jz 4f\n"
5a79859a HC	260	"1: algr %0,%2\n"
5a79859a HC	261	" slgr %1,%2\n"
457f2180 HC	262	" j 0b\n"
	263	"2: la %3,4095(%1)\n"/* %4 = to + 4095 */
	264	" nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
5a79859a HC	265	" slgr %3,%1\n"
5a79859a HC	266	" clgr %0,%3\n" /* copy crosses next page boundary? */
457f2180 HC	267	" jnh 5f\n"
457f2180 HC	268	"3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
5a79859a	269	" slgr %0,%3\n"
457f2180	270	" j 5f\n"
b8ac5e2f	271	"4: slgr %0,%0\n"
457f2180 HC	272	"5:\n"
	273	EX_TABLE(0b,2b) EX_TABLE(3b,5b)
	274	: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
	275	: "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
	276	return size;
	277	}
	278
	279	static inline unsigned long clear_user_xc(void __user *to, unsigned long size)
	280	{
	281	unsigned long tmp1, tmp2;
	282
beef560b	283	load_kernel_asce();
457f2180 HC	284	asm volatile(
457f2180 HC	285	" sacf 256\n"
5a79859a	286	" aghi %0,-1\n"
457f2180 HC	287	" jo 5f\n"
	288	" bras %3,3f\n"
	289	" xc 0(1,%1),0(%1)\n"
5a79859a	290	"0: aghi %0,257\n"
457f2180 HC	291	" la %2,255(%1)\n" /* %2 = ptr + 255 */
	292	" srl %2,12\n"
	293	" sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
5a79859a HC	294	" slgr %2,%1\n"
5a79859a HC	295	" clgr %0,%2\n" /* clear crosses next page boundary? */
457f2180	296	" jnh 5f\n"
5a79859a	297	" aghi %2,-1\n"
457f2180	298	"1: ex %2,0(%3)\n"
5a79859a HC	299	" aghi %2,1\n"
5a79859a HC	300	" slgr %0,%2\n"
457f2180 HC	301	" j 5f\n"
	302	"2: xc 0(256,%1),0(%1)\n"
	303	" la %1,256(%1)\n"
5a79859a	304	"3: aghi %0,-256\n"
457f2180 HC	305	" jnm 2b\n"
457f2180 HC	306	"4: ex %0,0(%3)\n"
5a79859a	307	"5: slgr %0,%0\n"
457f2180 HC	308	"6: sacf 768\n"
	309	EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
	310	: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
	311	: : "cc", "memory");
	312	return size;
	313	}
	314
	315	unsigned long __clear_user(void __user *to, unsigned long size)
	316	{
ed79e946	317	if (static_branch_likely(&have_mvcos))
457f2180 HC	318	return clear_user_mvcos(to, size);
	319	return clear_user_xc(to, size);
	320	}
	321	EXPORT_SYMBOL(__clear_user);
	322
	323	static inline unsigned long strnlen_user_srst(const char __user *src,
	324	unsigned long size)
	325	{
	326	register unsigned long reg0 asm("0") = 0;
	327	unsigned long tmp1, tmp2;
	328
457f2180 HC	329	asm volatile(
	330	" la %2,0(%1)\n"
	331	" la %3,0(%0,%1)\n"
5a79859a	332	" slgr %0,%0\n"
457f2180 HC	333	" sacf 256\n"
	334	"0: srst %3,%2\n"
	335	" jo 0b\n"
	336	" la %0,1(%3)\n" /* strnlen_user results includes \0 */
5a79859a	337	" slgr %0,%1\n"
457f2180 HC	338	"1: sacf 768\n"
	339	EX_TABLE(0b,1b)
	340	: "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
	341	: "d" (reg0) : "cc", "memory");
	342	return size;
	343	}
	344
	345	unsigned long __strnlen_user(const char __user *src, unsigned long size)
	346	{
fa255f51 HC	347	if (unlikely(!size))
fa255f51 HC	348	return 0;
beef560b	349	load_kernel_asce();
457f2180 HC	350	return strnlen_user_srst(src, size);
	351	}
	352	EXPORT_SYMBOL(__strnlen_user);
	353
	354	long __strncpy_from_user(char dst, const char __user src, long size)
	355	{
	356	size_t done, len, offset, len_str;
	357
	358	if (unlikely(size <= 0))
	359	return 0;
	360	done = 0;
	361	do {
	362	offset = (size_t)src & ~PAGE_MASK;
	363	len = min(size - done, PAGE_SIZE - offset);
	364	if (copy_from_user(dst, src, len))
	365	return -EFAULT;
	366	len_str = strnlen(dst, len);
	367	done += len_str;
	368	src += len_str;
	369	dst += len_str;
	370	} while ((len_str == len) && (done < size));
	371	return done;
	372	}
	373	EXPORT_SYMBOL(__strncpy_from_user);
	374
457f2180 HC	375	static int __init uaccess_init(void)
457f2180 HC	376	{
cabc4abe	377	if (test_facility(27))
ed79e946	378	static_branch_enable(&have_mvcos);
457f2180 HC	379	return 0;
	380	}
	381	early_initcall(uaccess_init);