linux/arch/ia64/sn/kernel/pio_phys.S
Jack Steiner dcc1dd2366 [IA64-SGI] - Eliminate SN pio_phys_xxx macros. Move to assembly
Rewrite the SN pio_phys_xxx macros in assembly language. This
avoids issues with the Intel icc compiler. Function call
overhead is not an issue - the functions reference PIOs
and take 100's nsec to complete.

In addition, the functions should likely be in assembly
language anyway - they reference memory using physical
addressing mode. One function executes with psr.ic disabled.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-02-07 09:24:14 -08:00

72 lines
1.4 KiB
ArmAsm

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2000-2005 Silicon Graphics, Inc. All rights reserved.
*
* This file contains macros used to access MMR registers via
* uncached physical addresses.
* pio_phys_read_mmr - read an MMR
* pio_phys_write_mmr - write an MMR
* pio_atomic_phys_write_mmrs - atomically write 1 or 2 MMRs with psr.ic=0
* Second MMR will be skipped if address is NULL
*
* Addresses passed to these routines should be uncached physical addresses
* ie., 0x80000....
*/
#include <asm/asmmacro.h>
#include <asm/page.h>
GLOBAL_ENTRY(pio_phys_read_mmr)
.prologue
.regstk 1,0,0,0
.body
mov r2=psr
rsm psr.i | psr.dt
;;
srlz.d
ld8.acq r8=[r32]
;;
mov psr.l=r2;;
srlz.d
br.ret.sptk.many rp
END(pio_phys_read_mmr)
GLOBAL_ENTRY(pio_phys_write_mmr)
.prologue
.regstk 2,0,0,0
.body
mov r2=psr
rsm psr.i | psr.dt
;;
srlz.d
st8.rel [r32]=r33
;;
mov psr.l=r2;;
srlz.d
br.ret.sptk.many rp
END(pio_phys_write_mmr)
GLOBAL_ENTRY(pio_atomic_phys_write_mmrs)
.prologue
.regstk 4,0,0,0
.body
mov r2=psr
cmp.ne p9,p0=r34,r0;
rsm psr.i | psr.dt | psr.ic
;;
srlz.d
st8.rel [r32]=r33
(p9) st8.rel [r34]=r35
;;
mov psr.l=r2;;
srlz.d
br.ret.sptk.many rp
END(pio_atomic_phys_write_mmrs)