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Commit 6c2a9e6d authored by Gerald Schaefer's avatar Gerald Schaefer Committed by Martin Schwidefsky
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[S390] Use alternative user-copy operations for new hardware. 



This introduces new user-copy operations which are optimized for
copying more than 256 Bytes on new hardware.

Signed-off-by: default avatarGerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent d02765d1

arch/s390/kernel/head64.S

+13 −0
Original line number Diff line number Diff line
@@ -250,6 +250,19 @@ startup_continue: 
	oi	7(%r12),0x80		# set IDTE flag

0:



#

# find out if we have the MVCOS instruction

#

	la	%r1,0f-.LPG1(%r13)	# set program check address

	stg	%r1,__LC_PGM_NEW_PSW+8

	.short	0xc800			# mvcos 0(%r0),0(%r0),%r0

	.short	0x0000

	.short	0x0000

0:	tm	0x8f,0x13		# special-operation exception?

	bno	1f-.LPG1(%r13)		# if yes, MVCOS is present

	oi	6(%r12),2		# set MVCOS flag

1:



        lpswe .Lentry-.LPG1(13)         # jump to _stext in primary-space,

                                        # virtual and never return ...

        .align 16

arch/s390/kernel/setup.c

+5 −1
Original line number Diff line number Diff line
@@ -647,7 +647,11 @@ setup_arch(char **cmdline_p) 


	memory_end = memory_size;



	if (MACHINE_HAS_MVCOS)

		memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));

	else

		memcpy(&uaccess, &uaccess_std, sizeof(uaccess));



	parse_early_param();



#ifndef CONFIG_64BIT

arch/s390/lib/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -5,4 +5,5 @@ 
EXTRA_AFLAGS := -traditional



lib-y += delay.o string.o uaccess_std.o

lib-$(CONFIG_64BIT) += uaccess_mvcos.o

lib-$(CONFIG_SMP) += spinlock.o

arch/s390/lib/uaccess_mvcos.c

0 → 100644
+156 −0
Original line number Diff line number Diff line 
/*

 *  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



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    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,%2),0(%1),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(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_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 copy_from_user_std_small(size_t, const void __user *, void *);

extern size_t copy_to_user_std_small(size_t, void __user *, const void *);

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,

	.copy_from_user_small = copy_from_user_std_small,

	.copy_to_user = copy_to_user_mvcos,

	.copy_to_user_small = copy_to_user_std_small,

	.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,

};

include/asm-s390/setup.h

+2 −0
Original line number Diff line number Diff line
@@ -44,10 +44,12 @@ extern unsigned long machine_flags; 
#define MACHINE_HAS_IEEE	(machine_flags & 2)

#define MACHINE_HAS_CSP		(machine_flags & 8)

#define MACHINE_HAS_DIAG44	(1)

#define MACHINE_HAS_MVCOS	(0)

#else /* __s390x__ */

#define MACHINE_HAS_IEEE	(1)

#define MACHINE_HAS_CSP		(1)

#define MACHINE_HAS_DIAG44	(machine_flags & 32)

#define MACHINE_HAS_MVCOS	(machine_flags & 512)

#endif /* __s390x__ */