linux_dsm_epyc7002/arch/powerpc/platforms/iseries/exception.h
Benjamin Herrenschmidt ee43eb788b powerpc: Use names rather than numbers for SPRGs (v2)
The kernel uses SPRG registers for various purposes, typically in
low level assembly code as scratch registers or to hold per-cpu
global infos such as the PACA or the current thread_info pointer.

We want to be able to easily shuffle the usage of those registers
as some implementations have specific constraints realted to some
of them, for example, some have userspace readable aliases, etc..
and the current choice isn't always the best.

This patch should not change any code generation, and replaces the
usage of SPRN_SPRGn everywhere in the kernel with a named replacement
and adds documentation next to the definition of the names as to
what those are used for on each processor family.

The only parts that still use the original numbers are bits of KVM
or suspend/resume code that just blindly needs to save/restore all
the SPRGs.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-08-20 10:12:27 +10:00

59 lines
1.9 KiB
C

#ifndef _ASM_POWERPC_ISERIES_EXCEPTION_H
#define _ASM_POWERPC_ISERIES_EXCEPTION_H
/*
* Extracted from head_64.S
*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
* Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
* Adapted for Power Macintosh by Paul Mackerras.
* Low-level exception handlers and MMU support
* rewritten by Paul Mackerras.
* Copyright (C) 1996 Paul Mackerras.
*
* Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
* Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
*
* This file contains the low-level support and setup for the
* PowerPC-64 platform, including trap and interrupt dispatch.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <asm/exception-64s.h>
#define EXCEPTION_PROLOG_ISERIES_1 \
mfmsr r10; \
ld r12,PACALPPACAPTR(r13); \
ld r11,LPPACASRR0(r12); \
ld r12,LPPACASRR1(r12); \
ori r10,r10,MSR_RI; \
mtmsrd r10,1
#define STD_EXCEPTION_ISERIES(label, area) \
.globl label##_iSeries; \
label##_iSeries: \
HMT_MEDIUM; \
mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
EXCEPTION_PROLOG_1(area); \
EXCEPTION_PROLOG_ISERIES_1; \
b label##_common
#define MASKABLE_EXCEPTION_ISERIES(label) \
.globl label##_iSeries; \
label##_iSeries: \
HMT_MEDIUM; \
mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
EXCEPTION_PROLOG_1(PACA_EXGEN); \
lbz r10,PACASOFTIRQEN(r13); \
cmpwi 0,r10,0; \
beq- label##_iSeries_masked; \
EXCEPTION_PROLOG_ISERIES_1; \
b label##_common; \
#endif /* _ASM_POWERPC_ISERIES_EXCEPTION_H */