linux/arch/mips/include/asm/prefetch.h
Shinya Kuribayashi a644b2774d MIPS: NEC VR5500 processor support fixup
Current VR5500 processor support lacks of some functions which are
expected to be configured/synthesized on arch initialization.

Here're some VR5500A spec notes:

* All execution hazards are handled in hardware.

* Once VR5500A stops the operation of the pipeline by WAIT instruction,
  it could return from the standby mode only when either a reset, NMI
  request, or all enabled interrupts is/are detected.  In other words,
  if interrupts are disabled by Status.IE=0, it keeps in standby mode
  even when interrupts are internally asserted.

  Notes on WAIT: The operation of the processor is undefined if WAIT
  insn is in the branch delay slot.  The operation is also undefined
  if WAIT insn is executed when Status.EXL and Status.ERL are set to 1.

* VR5500A core only implements the Load prefetch.

With these changes, it boots fine.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-03-11 21:11:07 +01:00

88 lines
2.1 KiB
C

/*
* 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) 2003 by Ralf Baechle
*/
#ifndef __ASM_PREFETCH_H
#define __ASM_PREFETCH_H
/*
* R5000 and RM5200 implements pref and prefx instructions but they're nops, so
* rather than wasting time we pretend these processors don't support
* prefetching at all.
*
* R5432 implements Load, Store, LoadStreamed, StoreStreamed, LoadRetained,
* StoreRetained and WriteBackInvalidate but not Pref_PrepareForStore.
*
* Hell (and the book on my shelf I can't open ...) know what the R8000 does.
*
* RM7000 version 1.0 interprets all hints as Pref_Load; version 2.0 implements
* Pref_PrepareForStore also.
*
* RM9000 is MIPS IV but implements prefetching like MIPS32/MIPS64; it's
* Pref_WriteBackInvalidate is a nop and Pref_PrepareForStore is broken in
* current versions due to erratum G105.
*
* VR5500 (including VR5701 and VR7701) only implement load prefetch.
*
* Finally MIPS32 and MIPS64 implement all of the following hints.
*/
#define Pref_Load 0
#define Pref_Store 1
/* 2 and 3 are reserved */
#define Pref_LoadStreamed 4
#define Pref_StoreStreamed 5
#define Pref_LoadRetained 6
#define Pref_StoreRetained 7
/* 8 ... 24 are reserved */
#define Pref_WriteBackInvalidate 25
#define Pref_PrepareForStore 30
#ifdef __ASSEMBLY__
.macro __pref hint addr
#ifdef CONFIG_CPU_HAS_PREFETCH
pref \hint, \addr
#endif
.endm
.macro pref_load addr
__pref Pref_Load, \addr
.endm
.macro pref_store addr
__pref Pref_Store, \addr
.endm
.macro pref_load_streamed addr
__pref Pref_LoadStreamed, \addr
.endm
.macro pref_store_streamed addr
__pref Pref_StoreStreamed, \addr
.endm
.macro pref_load_retained addr
__pref Pref_LoadRetained, \addr
.endm
.macro pref_store_retained addr
__pref Pref_StoreRetained, \addr
.endm
.macro pref_wback_inv addr
__pref Pref_WriteBackInvalidate, \addr
.endm
.macro pref_prepare_for_store addr
__pref Pref_PrepareForStore, \addr
.endm
#endif
#endif /* __ASM_PREFETCH_H */