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alistair23-linux/arch/powerpc/include/asm/exception.h
Paul Mackerras 1f6a93e4c3 powerpc: Make it possible to move the interrupt handlers away from the kernel 
This changes the way that the exception prologs transfer control to
the handlers in 64-bit kernels with the aim of making it possible to
have the prologs separate from the main body of the kernel.  Now,
instead of computing the address of the handler by taking the top
32 bits of the paca address (to get the 0xc0000000........ part) and
ORing in something in the bottom 16 bits, we get the base address of
the kernel by doing a load from the paca and add an offset.

This also replaces an mfmsr and an ori to compute the MSR value for
the handler with a load from the paca.  That makes it unnecessary to
have a separate version of EXCEPTION_PROLOG_PSERIES that forces 64-bit
mode.

We can no longer use a direct branches in the exception prolog code,
which means that the SLB miss handlers can't branch directly to
.slb_miss_realmode any more.  Instead we have to compute the address
and do an indirect branch.  This is conditional on CONFIG_RELOCATABLE;
for non-relocatable kernels we use a direct branch as before.  (A later
change will allow CONFIG_RELOCATABLE to be set on 64-bit powerpc.)

Since the secondary CPUs on pSeries start execution in the first 0x100
bytes of real memory and then have to get to wherever the kernel is,
we can't use a direct branch to get there.  Instead this changes
__secondary_hold_spinloop from a flag to a function pointer.  When it
is set to a non-NULL value, the secondary CPUs jump to the function
pointed to by that value.

Finally this eliminates one code difference between 32-bit and 64-bit
by making __secondary_hold be the text address of the secondary CPU
spinloop rather than a function descriptor for it.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-09-15 11:08:08 -07:00

280 lines
8.9 KiB
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#ifndef _ASM_POWERPC_EXCEPTION_H
#define _ASM_POWERPC_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.
*/
/*
* The following macros define the code that appears as
* the prologue to each of the exception handlers. They
* are split into two parts to allow a single kernel binary
* to be used for pSeries and iSeries.
*
* We make as much of the exception code common between native
* exception handlers (including pSeries LPAR) and iSeries LPAR
* implementations as possible.
*/
#define EX_R9 0
#define EX_R10 8
#define EX_R11 16
#define EX_R12 24
#define EX_R13 32
#define EX_SRR0 40
#define EX_DAR 48
#define EX_DSISR 56
#define EX_CCR 60
#define EX_R3 64
#define EX_LR 72
/*
* We're short on space and time in the exception prolog, so we can't
* use the normal SET_REG_IMMEDIATE macro. Normally we just need the
* low halfword of the address, but for Kdump we need the whole low
* word.
*/
#define LOAD_HANDLER(reg, label) \
addi reg,reg,(label)-_stext; /* virt addr of handler ... */
#define EXCEPTION_PROLOG_1(area) \
mfspr r13,SPRN_SPRG3; /* get paca address into r13 */ \
std r9,area+EX_R9(r13); /* save r9 - r12 */ \
std r10,area+EX_R10(r13); \
std r11,area+EX_R11(r13); \
std r12,area+EX_R12(r13); \
mfspr r9,SPRN_SPRG1; \
std r9,area+EX_R13(r13); \
mfcr r9
#define EXCEPTION_PROLOG_PSERIES(area, label) \
EXCEPTION_PROLOG_1(area); \
ld r12,PACAKBASE(r13); /* get high part of &label */ \
ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \
mfspr r11,SPRN_SRR0; /* save SRR0 */ \
LOAD_HANDLER(r12,label) \
mtspr SPRN_SRR0,r12; \
mfspr r12,SPRN_SRR1; /* and SRR1 */ \
mtspr SPRN_SRR1,r10; \
rfid; \
b . /* prevent speculative execution */
/*
* The common exception prolog is used for all except a few exceptions
* such as a segment miss on a kernel address. We have to be prepared
* to take another exception from the point where we first touch the
* kernel stack onwards.
*
* On entry r13 points to the paca, r9-r13 are saved in the paca,
* r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
* SRR1, and relocation is on.
*/
#define EXCEPTION_PROLOG_COMMON(n, area) \
andi. r10,r12,MSR_PR; /* See if coming from user */ \
mr r10,r1; /* Save r1 */ \
subi r1,r1,INT_FRAME_SIZE; /* alloc frame on kernel stack */ \
beq- 1f; \
ld r1,PACAKSAVE(r13); /* kernel stack to use */ \
1: cmpdi cr1,r1,0; /* check if r1 is in userspace */ \
bge- cr1,2f; /* abort if it is */ \
b 3f; \
2: li r1,(n); /* will be reloaded later */ \
sth r1,PACA_TRAP_SAVE(r13); \
b bad_stack; \
3: std r9,_CCR(r1); /* save CR in stackframe */ \
std r11,_NIP(r1); /* save SRR0 in stackframe */ \
std r12,_MSR(r1); /* save SRR1 in stackframe */ \
std r10,0(r1); /* make stack chain pointer */ \
std r0,GPR0(r1); /* save r0 in stackframe */ \
std r10,GPR1(r1); /* save r1 in stackframe */ \
ACCOUNT_CPU_USER_ENTRY(r9, r10); \
std r2,GPR2(r1); /* save r2 in stackframe */ \
SAVE_4GPRS(3, r1); /* save r3 - r6 in stackframe */ \
SAVE_2GPRS(7, r1); /* save r7, r8 in stackframe */ \
ld r9,area+EX_R9(r13); /* move r9, r10 to stackframe */ \
ld r10,area+EX_R10(r13); \
std r9,GPR9(r1); \
std r10,GPR10(r1); \
ld r9,area+EX_R11(r13); /* move r11 - r13 to stackframe */ \
ld r10,area+EX_R12(r13); \
ld r11,area+EX_R13(r13); \
std r9,GPR11(r1); \
std r10,GPR12(r1); \
std r11,GPR13(r1); \
ld r2,PACATOC(r13); /* get kernel TOC into r2 */ \
mflr r9; /* save LR in stackframe */ \
std r9,_LINK(r1); \
mfctr r10; /* save CTR in stackframe */ \
std r10,_CTR(r1); \
lbz r10,PACASOFTIRQEN(r13); \
mfspr r11,SPRN_XER; /* save XER in stackframe */ \
std r10,SOFTE(r1); \
std r11,_XER(r1); \
li r9,(n)+1; \
std r9,_TRAP(r1); /* set trap number */ \
li r10,0; \
ld r11,exception_marker@toc(r2); \
std r10,RESULT(r1); /* clear regs->result */ \
std r11,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame */
/*
* Exception vectors.
*/
#define STD_EXCEPTION_PSERIES(n, label) \
. = n; \
.globl label##_pSeries; \
label##_pSeries: \
HMT_MEDIUM; \
mtspr SPRN_SPRG1,r13; /* save r13 */ \
EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
#define HSTD_EXCEPTION_PSERIES(n, label) \
. = n; \
.globl label##_pSeries; \
label##_pSeries: \
HMT_MEDIUM; \
mtspr SPRN_SPRG1,r20; /* save r20 */ \
mfspr r20,SPRN_HSRR0; /* copy HSRR0 to SRR0 */ \
mtspr SPRN_SRR0,r20; \
mfspr r20,SPRN_HSRR1; /* copy HSRR0 to SRR0 */ \
mtspr SPRN_SRR1,r20; \
mfspr r20,SPRN_SPRG1; /* restore r20 */ \
mtspr SPRN_SPRG1,r13; /* save r13 */ \
EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
#define MASKABLE_EXCEPTION_PSERIES(n, label) \
. = n; \
.globl label##_pSeries; \
label##_pSeries: \
HMT_MEDIUM; \
mtspr SPRN_SPRG1,r13; /* save r13 */ \
mfspr r13,SPRN_SPRG3; /* get paca address into r13 */ \
std r9,PACA_EXGEN+EX_R9(r13); /* save r9, r10 */ \
std r10,PACA_EXGEN+EX_R10(r13); \
lbz r10,PACASOFTIRQEN(r13); \
mfcr r9; \
cmpwi r10,0; \
beq masked_interrupt; \
mfspr r10,SPRN_SPRG1; \
std r10,PACA_EXGEN+EX_R13(r13); \
std r11,PACA_EXGEN+EX_R11(r13); \
std r12,PACA_EXGEN+EX_R12(r13); \
ld r12,PACAKBASE(r13); /* get high part of &label */ \
ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \
mfspr r11,SPRN_SRR0; /* save SRR0 */ \
LOAD_HANDLER(r12,label##_common) \
mtspr SPRN_SRR0,r12; \
mfspr r12,SPRN_SRR1; /* and SRR1 */ \
mtspr SPRN_SRR1,r10; \
rfid; \
b . /* prevent speculative execution */
#ifdef CONFIG_PPC_ISERIES
#define DISABLE_INTS \
li r11,0; \
stb r11,PACASOFTIRQEN(r13); \
BEGIN_FW_FTR_SECTION; \
stb r11,PACAHARDIRQEN(r13); \
END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES); \
TRACE_DISABLE_INTS; \
BEGIN_FW_FTR_SECTION; \
mfmsr r10; \
ori r10,r10,MSR_EE; \
mtmsrd r10,1; \
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#else
#define DISABLE_INTS \
li r11,0; \
stb r11,PACASOFTIRQEN(r13); \
stb r11,PACAHARDIRQEN(r13); \
TRACE_DISABLE_INTS
#endif /* CONFIG_PPC_ISERIES */
#define ENABLE_INTS \
ld r12,_MSR(r1); \
mfmsr r11; \
rlwimi r11,r12,0,MSR_EE; \
mtmsrd r11,1
#define STD_EXCEPTION_COMMON(trap, label, hdlr) \
.align 7; \
.globl label##_common; \
label##_common: \
EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
DISABLE_INTS; \
bl .save_nvgprs; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
bl hdlr; \
b .ret_from_except
/*
* Like STD_EXCEPTION_COMMON, but for exceptions that can occur
* in the idle task and therefore need the special idle handling.
*/
#define STD_EXCEPTION_COMMON_IDLE(trap, label, hdlr) \
.align 7; \
.globl label##_common; \
label##_common: \
EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
FINISH_NAP; \
DISABLE_INTS; \
bl .save_nvgprs; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
bl hdlr; \
b .ret_from_except
#define STD_EXCEPTION_COMMON_LITE(trap, label, hdlr) \
.align 7; \
.globl label##_common; \
label##_common: \
EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
FINISH_NAP; \
DISABLE_INTS; \
BEGIN_FTR_SECTION \
bl .ppc64_runlatch_on; \
END_FTR_SECTION_IFSET(CPU_FTR_CTRL) \
addi r3,r1,STACK_FRAME_OVERHEAD; \
bl hdlr; \
b .ret_from_except_lite
/*
* When the idle code in power4_idle puts the CPU into NAP mode,
* it has to do so in a loop, and relies on the external interrupt
* and decrementer interrupt entry code to get it out of the loop.
* It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
* to signal that it is in the loop and needs help to get out.
*/
#ifdef CONFIG_PPC_970_NAP
#define FINISH_NAP \
BEGIN_FTR_SECTION \
clrrdi r11,r1,THREAD_SHIFT; \
ld r9,TI_LOCAL_FLAGS(r11); \
andi. r10,r9,_TLF_NAPPING; \
bnel power4_fixup_nap; \
END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
#else
#define FINISH_NAP
#endif
#endif /* _ASM_POWERPC_EXCEPTION_H */
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