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

/*
 *  Optimized user space space access functions based on mvcos.
 *
 *    Copyright 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>
#include "uaccess.h"

#ifndef CONFIG_64BIT
#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

static 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"
		"9: 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"
		"10:"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) 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 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"
		"6: 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"
		"7:"SLR"  %0,%4\n"
		"   j     5f\n"
		"4:"SLR"  %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 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;
}

static 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;
}

static size_t strnlen_user_mvcos(size_t count, const char __user *src)
{
	size_t done, len, offset, len_str;
	char buf[256];

	done = 0;
	do {
		offset = (size_t)src & ~PAGE_MASK;
		len = min(256UL, PAGE_SIZE - offset);
		len = min(count - done, len);
		if (copy_from_user_mvcos(len, src, buf))
			return 0;
		len_str = strnlen(buf, len);
		done += len_str;
		src += len_str;
	} while ((len_str == len) && (done < count));
	return done + 1;
}

static size_t strncpy_from_user_mvcos(size_t count, const char __user *src,
				      char *dst)
{
	size_t done, len, offset, len_str;

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

struct uaccess_ops uaccess_mvcos = {
	.copy_from_user = copy_from_user_mvcos,
	.copy_to_user = copy_to_user_mvcos,
	.copy_in_user = copy_in_user_mvcos,
	.clear_user = clear_user_mvcos,
	.strnlen_user = strnlen_user_mvcos,
	.strncpy_from_user = strncpy_from_user_mvcos,
	.futex_atomic_op = futex_atomic_op_pt,
	.futex_atomic_cmpxchg = futex_atomic_cmpxchg_pt,
};
Commit	Line	Data
	1	/*
	2	* Optimized user space space access functions based on mvcos.
	3	*
	4	* Copyright IBM Corp. 2006
	5	* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
	6	* Gerald Schaefer (gerald.schaefer@de.ibm.com)
	7	*/
	8
	9	#include <linux/errno.h>
	10	#include <linux/mm.h>
	11	#include <asm/uaccess.h>
	12	#include <asm/futex.h>
	13	#include "uaccess.h"
	14
	15	#ifndef CONFIG_64BIT
	16	#define AHI "ahi"
	17	#define ALR "alr"
	18	#define CLR "clr"
	19	#define LHI "lhi"
	20	#define SLR "slr"
	21	#else
	22	#define AHI "aghi"
	23	#define ALR "algr"
	24	#define CLR "clgr"
	25	#define LHI "lghi"
	26	#define SLR "slgr"
	27	#endif
	28
	29	static size_t copy_from_user_mvcos(size_t size, const void __user ptr, void x)
	30	{
	31	register unsigned long reg0 asm("0") = 0x81UL;
	32	unsigned long tmp1, tmp2;
	33
	34	tmp1 = -4096UL;
	35	asm volatile(
	36	"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
	37	"9: jz 7f\n"
	38	"1:"ALR" %0,%3\n"
	39	" "SLR" %1,%3\n"
	40	" "SLR" %2,%3\n"
	41	" j 0b\n"
	42	"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
	43	" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
	44	" "SLR" %4,%1\n"
	45	" "CLR" %0,%4\n" /* copy crosses next page boundary? */
	46	" jnh 4f\n"
	47	"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
	48	"10:"SLR" %0,%4\n"
	49	" "ALR" %2,%4\n"
	50	"4:"LHI" %4,-1\n"
	51	" "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
	52	" bras %3,6f\n" /* memset loop */
	53	" xc 0(1,%2),0(%2)\n"
	54	"5: xc 0(256,%2),0(%2)\n"
	55	" la %2,256(%2)\n"
	56	"6:"AHI" %4,-256\n"
	57	" jnm 5b\n"
	58	" ex %4,0(%3)\n"
	59	" j 8f\n"
	60	"7:"SLR" %0,%0\n"
	61	"8: \n"
	62	EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
	63	: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
	64	: "d" (reg0) : "cc", "memory");
	65	return size;
	66	}
	67
	68	static size_t copy_to_user_mvcos(size_t size, void __user ptr, const void x)
	69	{
	70	register unsigned long reg0 asm("0") = 0x810000UL;
	71	unsigned long tmp1, tmp2;
	72
	73	tmp1 = -4096UL;
	74	asm volatile(
	75	"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
	76	"6: jz 4f\n"
	77	"1:"ALR" %0,%3\n"
	78	" "SLR" %1,%3\n"
	79	" "SLR" %2,%3\n"
	80	" j 0b\n"
	81	"2: la %4,4095(%1)\n"/* %4 = ptr + 4095 */
	82	" nr %4,%3\n" /* %4 = (ptr + 4095) & -4096 */
	83	" "SLR" %4,%1\n"
	84	" "CLR" %0,%4\n" /* copy crosses next page boundary? */
	85	" jnh 5f\n"
	86	"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
	87	"7:"SLR" %0,%4\n"
	88	" j 5f\n"
	89	"4:"SLR" %0,%0\n"
	90	"5: \n"
	91	EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
	92	: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
	93	: "d" (reg0) : "cc", "memory");
	94	return size;
	95	}
	96
	97	static size_t copy_in_user_mvcos(size_t size, void __user *to,
	98	const void __user *from)
	99	{
	100	register unsigned long reg0 asm("0") = 0x810081UL;
	101	unsigned long tmp1, tmp2;
	102
	103	tmp1 = -4096UL;
	104	/* FIXME: copy with reduced length. */
	105	asm volatile(
	106	"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
	107	" jz 2f\n"
	108	"1:"ALR" %0,%3\n"
	109	" "SLR" %1,%3\n"
	110	" "SLR" %2,%3\n"
	111	" j 0b\n"
	112	"2:"SLR" %0,%0\n"
	113	"3: \n"
	114	EX_TABLE(0b,3b)
	115	: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
	116	: "d" (reg0) : "cc", "memory");
	117	return size;
	118	}
	119
	120	static size_t clear_user_mvcos(size_t size, void __user *to)
	121	{
	122	register unsigned long reg0 asm("0") = 0x810000UL;
	123	unsigned long tmp1, tmp2;
	124
	125	tmp1 = -4096UL;
	126	asm volatile(
	127	"0: .insn ss,0xc80000000000,0(%0,%1),0(%4),0\n"
	128	" jz 4f\n"
	129	"1:"ALR" %0,%2\n"
	130	" "SLR" %1,%2\n"
	131	" j 0b\n"
	132	"2: la %3,4095(%1)\n"/* %4 = to + 4095 */
	133	" nr %3,%2\n" /* %4 = (to + 4095) & -4096 */
	134	" "SLR" %3,%1\n"
	135	" "CLR" %0,%3\n" /* copy crosses next page boundary? */
	136	" jnh 5f\n"
	137	"3: .insn ss,0xc80000000000,0(%3,%1),0(%4),0\n"
	138	" "SLR" %0,%3\n"
	139	" j 5f\n"
	140	"4:"SLR" %0,%0\n"
	141	"5: \n"
	142	EX_TABLE(0b,2b) EX_TABLE(3b,5b)
	143	: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
	144	: "a" (empty_zero_page), "d" (reg0) : "cc", "memory");
	145	return size;
	146	}
	147
	148	static size_t strnlen_user_mvcos(size_t count, const char __user *src)
	149	{
	150	size_t done, len, offset, len_str;
	151	char buf[256];
	152
	153	done = 0;
	154	do {
	155	offset = (size_t)src & ~PAGE_MASK;
	156	len = min(256UL, PAGE_SIZE - offset);
	157	len = min(count - done, len);
	158	if (copy_from_user_mvcos(len, src, buf))
	159	return 0;
	160	len_str = strnlen(buf, len);
	161	done += len_str;
	162	src += len_str;
	163	} while ((len_str == len) && (done < count));
	164	return done + 1;
	165	}
	166
	167	static size_t strncpy_from_user_mvcos(size_t count, const char __user *src,
	168	char *dst)
	169	{
	170	size_t done, len, offset, len_str;
	171
	172	if (unlikely(!count))
	173	return 0;
	174	done = 0;
	175	do {
	176	offset = (size_t)src & ~PAGE_MASK;
	177	len = min(count - done, PAGE_SIZE - offset);
	178	if (copy_from_user_mvcos(len, src, dst))
	179	return -EFAULT;
	180	len_str = strnlen(dst, len);
	181	done += len_str;
	182	src += len_str;
	183	dst += len_str;
	184	} while ((len_str == len) && (done < count));
	185	return done;
	186	}
	187
	188	struct uaccess_ops uaccess_mvcos = {
	189	.copy_from_user = copy_from_user_mvcos,
	190	.copy_to_user = copy_to_user_mvcos,
	191	.copy_in_user = copy_in_user_mvcos,
	192	.clear_user = clear_user_mvcos,
	193	.strnlen_user = strnlen_user_mvcos,
	194	.strncpy_from_user = strncpy_from_user_mvcos,
	195	.futex_atomic_op = futex_atomic_op_pt,
	196	.futex_atomic_cmpxchg = futex_atomic_cmpxchg_pt,
	197	};