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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: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
hifive-unleashed-5.1
Gerald Schaefer 2006-09-20 15:59:44 +02:00 committed by Martin Schwidefsky
parent d02765d1af
commit 6c2a9e6df6
6 changed files with 178 additions and 1 deletions
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13
arch/s390/kernel/head64.S
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@ -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

6
arch/s390/kernel/setup.c
View File

@ -647,7 +647,11 @@ setup_arch(char **cmdline_p)
memory_end = memory_size;
memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
if (MACHINE_HAS_MVCOS)
memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
else
memcpy(&uaccess, &uaccess_std, sizeof(uaccess));
parse_early_param();
#ifndef CONFIG_64BIT

1
arch/s390/lib/Makefile
View File

@ -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

156
arch/s390/lib/uaccess_mvcos.c 100644
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@ -0,0 +1,156 @@
/*
* 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,
};

2
include/asm-s390/setup.h
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@ -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__ */

1
include/asm-s390/uaccess.h
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@ -100,6 +100,7 @@ struct uaccess_ops {
extern struct uaccess_ops uaccess;
extern struct uaccess_ops uaccess_std;
extern struct uaccess_ops uaccess_mvcos;
static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
{