linux/arch/sparc/lib/NG2copy_to_user.S
David S. Miller 83a17d2661 sparc64: Prepare to move to more saner user copy exception handling.
The fixup helper function mechanism for handling user copy fault
handling is not %100 accurrate, and can never be made so.

We are going to transition the code to return the running return
return length, which is always kept track in one or more registers
of each of these routines.

In order to convert them one by one, we have to allow the existing
behavior to continue functioning.

Therefore make all the copy code that wants the fixup helper to be
used return negative one.

After all of the user copy routines have been converted, this logic
and the fixup helpers themselves can be removed completely.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-24 11:31:58 -07:00

53 lines
1.1 KiB
ArmAsm

/* NG2copy_to_user.S: Niagara-2 optimized copy to userspace.
*
* Copyright (C) 2007 David S. Miller (davem@davemloft.net)
*/
#define EX_ST(x) \
98: x; \
.section __ex_table,"a";\
.align 4; \
.word 98b, __retl_mone_asi;\
.text; \
.align 4;
#define EX_ST_FP(x) \
98: x; \
.section __ex_table,"a";\
.align 4; \
.word 98b, __retl_mone_asi_fp;\
.text; \
.align 4;
#ifndef ASI_AIUS
#define ASI_AIUS 0x11
#endif
#ifndef ASI_BLK_AIUS_4V
#define ASI_BLK_AIUS_4V 0x17
#endif
#ifndef ASI_BLK_INIT_QUAD_LDD_AIUS
#define ASI_BLK_INIT_QUAD_LDD_AIUS 0x23
#endif
#define FUNC_NAME NG2copy_to_user
#define STORE(type,src,addr) type##a src, [addr] ASI_AIUS
#define STORE_ASI ASI_BLK_INIT_QUAD_LDD_AIUS
#define STORE_BLK(src,addr) stda src, [addr] ASI_BLK_AIUS_4V
#define EX_RETVAL(x) 0
#ifdef __KERNEL__
/* Writing to %asi is _expensive_ so we hardcode it.
* Reading %asi to check for KERNEL_DS is comparatively
* cheap.
*/
#define PREAMBLE \
rd %asi, %g1; \
cmp %g1, ASI_AIUS; \
bne,pn %icc, ___copy_in_user; \
nop
#endif
#include "NG2memcpy.S"