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kernel_xiaomi_sm8250/arch/powerpc/include/asm/exception-64s.h
Michael Ellerman bf1b11ac0d powerpc/64s: Unmerge EX_LR and EX_DAR 
The SLB miss handler is not fully re-entrant, it is able to work because
we ensure that the SLB entries for the kernel text and data segment, as
well as the kernel stack are pinned in the SLB. Accesses to kernel data
outside of those areas has to be carefully managed and can only occur in
certain parts of the code. One way we deal with that is by storing some
values in temporary slots in the paca.

In v4.13 in commit dbeea1d6b4 ("powerpc/64s/paca: EX_LR can be merged
with EX_DAR") we merged the storage for two temporary slots for register
storage during SLB miss handling. That was safe at the time because the
two slots were never used at the same time.

Unfortunately in v4.17 in commit c2b4d8b741 ("powerpc/mm/hash64:
Increase the VA range") we broke that condition, and introduced a case
where the two slots could be in use at the same time, leading to one
being corrupted.

Specifically in slb_miss_common() when we detect that we're handling a
fault for a large virtual address (> 512TB) we go to the "8" label,
there we store the original fault address into paca->exslb[EX_DAR],
before jumping to large_addr_slb() (using rfid).

We then use the EXCEPTION_PROLOG_COMMON and RECONCILE_IRQ_STATE macros
to do exception setup, before reloading the fault address from
paca->exslb[EX_DAR] and storing it into pt_regs->dar (Data Address
Register).

However the code generated by those macros can cause a recursive SLB
miss on a kernel address in three places.

Firstly is the saving of the PPR (Program Priority Register), which
happens on all CPUs since Power7, the PPR is saved to the thread struct
which can be anywhere in memory. There is also the call to
accumulate_stolen_time() if CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y and
CONFIG_PPC_SPLPAR=y, and also the call to trace_hardirqs_off() if
CONFIG_TRACE_IRQFLAGS=y. The latter two call into generic C code and can
lead to accesses anywhere in memory.

On modern 64-bit CPUs we have 1TB segments, so for any of those accesses
to cause an SLB fault they must access memory more than 1TB away from
the kernel text, data and kernel stack. That typically only happens on
machines with more than 1TB of RAM. However it is possible on multi-node
Power9 systems, because memory on the 2nd node begins at 32TB in the
linear mapping.

If we take a recursive SLB fault then we will corrupt the original fault
address with the LR (Link Register) value, because the EX_DAR and EX_LR
slots share storage. Subsequently we will think we're trying to fault
that LR address, which is the wrong address, and will also mostly likely
lead to a segfault because the LR address will be < 512TB and so will be
rejected by slb_miss_large_addr().

This appears as a spurious segfault to userspace, and if
show_unhandled_signals is enabled you will see a fault reported in dmesg
with the LR address, not the expected fault address, eg:

  prog[123]: segfault (11) at 128a61808 nip 128a618cc lr 128a61808 code 3 in prog[128a60000+10000]
  prog[123]: code: 4bffffa4 39200040 3ce00004 7d2903a6 3c000200 78e707c6 780083e4 7d3b4b78
  prog[123]: code: 7d455378 7d7d5b78 7d9f6378 7da46b78 <f8670000> 7d3a4b78 7d465378 7d7c5b78

Notice that the fault address == the LR, and the faulting instruction is
a simple store that should never use LR.

In upstream this was fixed in v4.20 in commit
48e7b7695745 ("powerpc/64s/hash: Convert SLB miss handlers to C"),
however that is a huge rewrite and not backportable.

The minimal fix for stable is to just unmerge the EX_LR and EX_DAR slots
again, avoiding the corruption of the DAR value. This uses an extra 8
bytes per CPU, which is negligble.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-01 17:00:36 +02:00

757 lines
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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.
*/
#include <asm/head-64.h>
#include <asm/feature-fixups.h>
/* PACA save area offsets (exgen, exmc, etc) */
#define EX_R9 0
#define EX_R10 8
#define EX_R11 16
#define EX_R12 24
#define EX_R13 32
#define EX_DAR 40
#define EX_DSISR 48
#define EX_CCR 52
#define EX_CFAR 56
#define EX_PPR 64
#define EX_LR 72
#if defined(CONFIG_RELOCATABLE)
#define EX_CTR 80
#define EX_SIZE 11 /* size in u64 units */
#else
#define EX_SIZE 10 /* size in u64 units */
#endif
/*
* maximum recursive depth of MCE exceptions
*/
#define MAX_MCE_DEPTH 4
/*
* EX_R3 is only used by the bad_stack handler. bad_stack reloads and
* saves DAR from SPRN_DAR, and EX_DAR is not used. So EX_R3 can overlap
* with EX_DAR.
*/
#define EX_R3 EX_DAR
#define STF_ENTRY_BARRIER_SLOT \
STF_ENTRY_BARRIER_FIXUP_SECTION; \
nop; \
nop; \
nop
#define STF_EXIT_BARRIER_SLOT \
STF_EXIT_BARRIER_FIXUP_SECTION; \
nop; \
nop; \
nop; \
nop; \
nop; \
nop
#define ENTRY_FLUSH_SLOT \
ENTRY_FLUSH_FIXUP_SECTION; \
nop; \
nop; \
nop;
/*
* r10 must be free to use, r13 must be paca
*/
#define INTERRUPT_TO_KERNEL \
STF_ENTRY_BARRIER_SLOT; \
ENTRY_FLUSH_SLOT
/*
* Macros for annotating the expected destination of (h)rfid
*
* The nop instructions allow us to insert one or more instructions to flush the
* L1-D cache when returning to userspace or a guest.
*/
#define RFI_FLUSH_SLOT \
RFI_FLUSH_FIXUP_SECTION; \
nop; \
nop; \
nop
#define RFI_TO_KERNEL \
rfid
#define RFI_TO_USER \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
rfid; \
b rfi_flush_fallback
#define RFI_TO_USER_OR_KERNEL \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
rfid; \
b rfi_flush_fallback
#define RFI_TO_GUEST \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
rfid; \
b rfi_flush_fallback
#define HRFI_TO_KERNEL \
hrfid
#define HRFI_TO_USER \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
hrfid; \
b hrfi_flush_fallback
#define HRFI_TO_USER_OR_KERNEL \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
hrfid; \
b hrfi_flush_fallback
#define HRFI_TO_GUEST \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
hrfid; \
b hrfi_flush_fallback
#define HRFI_TO_UNKNOWN \
STF_EXIT_BARRIER_SLOT; \
RFI_FLUSH_SLOT; \
hrfid; \
b hrfi_flush_fallback
#ifdef CONFIG_RELOCATABLE
#define __EXCEPTION_PROLOG_2_RELON(label, h) \
mfspr r11,SPRN_##h##SRR0; /* save SRR0 */ \
LOAD_HANDLER(r12,label); \
mtctr r12; \
mfspr r12,SPRN_##h##SRR1; /* and SRR1 */ \
li r10,MSR_RI; \
mtmsrd r10,1; /* Set RI (EE=0) */ \
bctr;
#else
/* If not relocatable, we can jump directly -- and save messing with LR */
#define __EXCEPTION_PROLOG_2_RELON(label, h) \
mfspr r11,SPRN_##h##SRR0; /* save SRR0 */ \
mfspr r12,SPRN_##h##SRR1; /* and SRR1 */ \
li r10,MSR_RI; \
mtmsrd r10,1; /* Set RI (EE=0) */ \
b label;
#endif
#define EXCEPTION_PROLOG_2_RELON(label, h) \
__EXCEPTION_PROLOG_2_RELON(label, h)
/*
* As EXCEPTION_PROLOG(), except we've already got relocation on so no need to
* rfid. Save LR in case we're CONFIG_RELOCATABLE, in which case
* EXCEPTION_PROLOG_2_RELON will be using LR.
*/
#define EXCEPTION_RELON_PROLOG(area, label, h, extra, vec) \
SET_SCRATCH0(r13); /* save r13 */ \
EXCEPTION_PROLOG_0(area); \
EXCEPTION_PROLOG_1(area, extra, vec); \
EXCEPTION_PROLOG_2_RELON(label, h)
/*
* We're short on space and time in the exception prolog, so we can't
* use the normal LOAD_REG_IMMEDIATE macro to load the address of label.
* Instead we get the base of the kernel from paca->kernelbase and or in the low
* part of label. This requires that the label be within 64KB of kernelbase, and
* that kernelbase be 64K aligned.
*/
#define LOAD_HANDLER(reg, label) \
ld reg,PACAKBASE(r13); /* get high part of &label */ \
ori reg,reg,FIXED_SYMBOL_ABS_ADDR(label);
#define __LOAD_HANDLER(reg, label) \
ld reg,PACAKBASE(r13); \
ori reg,reg,(ABS_ADDR(label))@l;
/*
* Branches from unrelocated code (e.g., interrupts) to labels outside
* head-y require >64K offsets.
*/
#define __LOAD_FAR_HANDLER(reg, label) \
ld reg,PACAKBASE(r13); \
ori reg,reg,(ABS_ADDR(label))@l; \
addis reg,reg,(ABS_ADDR(label))@h;
/* Exception register prefixes */
#define EXC_HV H
#define EXC_STD
#if defined(CONFIG_RELOCATABLE)
/*
* If we support interrupts with relocation on AND we're a relocatable kernel,
* we need to use CTR to get to the 2nd level handler. So, save/restore it
* when required.
*/
#define SAVE_CTR(reg, area) mfctr reg ; std reg,area+EX_CTR(r13)
#define GET_CTR(reg, area) ld reg,area+EX_CTR(r13)
#define RESTORE_CTR(reg, area) ld reg,area+EX_CTR(r13) ; mtctr reg
#else
/* ...else CTR is unused and in register. */
#define SAVE_CTR(reg, area)
#define GET_CTR(reg, area) mfctr reg
#define RESTORE_CTR(reg, area)
#endif
/*
* PPR save/restore macros used in exceptions_64s.S
* Used for P7 or later processors
*/
#define SAVE_PPR(area, ra) \
BEGIN_FTR_SECTION_NESTED(940) \
ld ra,area+EX_PPR(r13); /* Read PPR from paca */ \
std ra,RESULT(r1); /* Store PPR in RESULT for now */ \
END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,940)
/*
* This is called after we are finished accessing 'area', so we can now take
* SLB faults accessing the thread struct, which will use PACA_EXSLB area.
* This is required because the large_addr_slb handler uses EXSLB and it also
* uses the common exception macros including this PPR saving.
*/
#define MOVE_PPR_TO_THREAD(ra, rb) \
BEGIN_FTR_SECTION_NESTED(940) \
ld ra,PACACURRENT(r13); \
ld rb,RESULT(r1); /* Read PPR from stack */ \
std rb,TASKTHREADPPR(ra); \
END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,940)
#define RESTORE_PPR_PACA(area, ra) \
BEGIN_FTR_SECTION_NESTED(941) \
ld ra,area+EX_PPR(r13); \
mtspr SPRN_PPR,ra; \
END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,941)
/*
* Get an SPR into a register if the CPU has the given feature
*/
#define OPT_GET_SPR(ra, spr, ftr) \
BEGIN_FTR_SECTION_NESTED(943) \
mfspr ra,spr; \
END_FTR_SECTION_NESTED(ftr,ftr,943)
/*
* Set an SPR from a register if the CPU has the given feature
*/
#define OPT_SET_SPR(ra, spr, ftr) \
BEGIN_FTR_SECTION_NESTED(943) \
mtspr spr,ra; \
END_FTR_SECTION_NESTED(ftr,ftr,943)
/*
* Save a register to the PACA if the CPU has the given feature
*/
#define OPT_SAVE_REG_TO_PACA(offset, ra, ftr) \
BEGIN_FTR_SECTION_NESTED(943) \
std ra,offset(r13); \
END_FTR_SECTION_NESTED(ftr,ftr,943)
#define EXCEPTION_PROLOG_0(area) \
GET_PACA(r13); \
std r9,area+EX_R9(r13); /* save r9 */ \
OPT_GET_SPR(r9, SPRN_PPR, CPU_FTR_HAS_PPR); \
HMT_MEDIUM; \
std r10,area+EX_R10(r13); /* save r10 - r12 */ \
OPT_GET_SPR(r10, SPRN_CFAR, CPU_FTR_CFAR)
#define __EXCEPTION_PROLOG_1_PRE(area) \
OPT_SAVE_REG_TO_PACA(area+EX_PPR, r9, CPU_FTR_HAS_PPR); \
OPT_SAVE_REG_TO_PACA(area+EX_CFAR, r10, CPU_FTR_CFAR); \
INTERRUPT_TO_KERNEL; \
SAVE_CTR(r10, area); \
mfcr r9;
#define __EXCEPTION_PROLOG_1_POST(area) \
std r11,area+EX_R11(r13); \
std r12,area+EX_R12(r13); \
GET_SCRATCH0(r10); \
std r10,area+EX_R13(r13)
/*
* This version of the EXCEPTION_PROLOG_1 will carry
* addition parameter called "bitmask" to support
* checking of the interrupt maskable level in the SOFTEN_TEST.
* Intended to be used in MASKABLE_EXCPETION_* macros.
*/
#define MASKABLE_EXCEPTION_PROLOG_1(area, extra, vec, bitmask) \
__EXCEPTION_PROLOG_1_PRE(area); \
extra(vec, bitmask); \
__EXCEPTION_PROLOG_1_POST(area);
/*
* This version of the EXCEPTION_PROLOG_1 is intended
* to be used in STD_EXCEPTION* macros
*/
#define _EXCEPTION_PROLOG_1(area, extra, vec) \
__EXCEPTION_PROLOG_1_PRE(area); \
extra(vec); \
__EXCEPTION_PROLOG_1_POST(area);
#define EXCEPTION_PROLOG_1(area, extra, vec) \
_EXCEPTION_PROLOG_1(area, extra, vec)
#define __EXCEPTION_PROLOG_2(label, h) \
ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \
mfspr r11,SPRN_##h##SRR0; /* save SRR0 */ \
LOAD_HANDLER(r12,label) \
mtspr SPRN_##h##SRR0,r12; \
mfspr r12,SPRN_##h##SRR1; /* and SRR1 */ \
mtspr SPRN_##h##SRR1,r10; \
h##RFI_TO_KERNEL; \
b . /* prevent speculative execution */
#define EXCEPTION_PROLOG_2(label, h) \
__EXCEPTION_PROLOG_2(label, h)
/* _NORI variant keeps MSR_RI clear */
#define __EXCEPTION_PROLOG_2_NORI(label, h) \
ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \
xori r10,r10,MSR_RI; /* Clear MSR_RI */ \
mfspr r11,SPRN_##h##SRR0; /* save SRR0 */ \
LOAD_HANDLER(r12,label) \
mtspr SPRN_##h##SRR0,r12; \
mfspr r12,SPRN_##h##SRR1; /* and SRR1 */ \
mtspr SPRN_##h##SRR1,r10; \
h##RFI_TO_KERNEL; \
b . /* prevent speculative execution */
#define EXCEPTION_PROLOG_2_NORI(label, h) \
__EXCEPTION_PROLOG_2_NORI(label, h)
#define EXCEPTION_PROLOG(area, label, h, extra, vec) \
SET_SCRATCH0(r13); /* save r13 */ \
EXCEPTION_PROLOG_0(area); \
EXCEPTION_PROLOG_1(area, extra, vec); \
EXCEPTION_PROLOG_2(label, h);
#define __KVMTEST(h, n) \
lbz r10,HSTATE_IN_GUEST(r13); \
cmpwi r10,0; \
bne do_kvm_##h##n
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
/*
* If hv is possible, interrupts come into to the hv version
* of the kvmppc_interrupt code, which then jumps to the PR handler,
* kvmppc_interrupt_pr, if the guest is a PR guest.
*/
#define kvmppc_interrupt kvmppc_interrupt_hv
#else
#define kvmppc_interrupt kvmppc_interrupt_pr
#endif
/*
* Branch to label using its 0xC000 address. This results in instruction
* address suitable for MSR[IR]=0 or 1, which allows relocation to be turned
* on using mtmsr rather than rfid.
*
* This could set the 0xc bits for !RELOCATABLE as an immediate, rather than
* load KBASE for a slight optimisation.
*/
#define BRANCH_TO_C000(reg, label) \
__LOAD_HANDLER(reg, label); \
mtctr reg; \
bctr
#ifdef CONFIG_RELOCATABLE
#define BRANCH_TO_COMMON(reg, label) \
__LOAD_HANDLER(reg, label); \
mtctr reg; \
bctr
#define BRANCH_LINK_TO_FAR(label) \
__LOAD_FAR_HANDLER(r12, label); \
mtctr r12; \
bctrl
/*
* KVM requires __LOAD_FAR_HANDLER.
*
* __BRANCH_TO_KVM_EXIT branches are also a special case because they
* explicitly use r9 then reload it from PACA before branching. Hence
* the double-underscore.
*/
#define __BRANCH_TO_KVM_EXIT(area, label) \
mfctr r9; \
std r9,HSTATE_SCRATCH1(r13); \
__LOAD_FAR_HANDLER(r9, label); \
mtctr r9; \
ld r9,area+EX_R9(r13); \
bctr
#else
#define BRANCH_TO_COMMON(reg, label) \
b label
#define BRANCH_LINK_TO_FAR(label) \
bl label
#define __BRANCH_TO_KVM_EXIT(area, label) \
ld r9,area+EX_R9(r13); \
b label
#endif
/* Do not enable RI */
#define EXCEPTION_PROLOG_NORI(area, label, h, extra, vec) \
EXCEPTION_PROLOG_0(area); \
EXCEPTION_PROLOG_1(area, extra, vec); \
EXCEPTION_PROLOG_2_NORI(label, h);
#define __KVM_HANDLER(area, h, n) \
BEGIN_FTR_SECTION_NESTED(947) \
ld r10,area+EX_CFAR(r13); \
std r10,HSTATE_CFAR(r13); \
END_FTR_SECTION_NESTED(CPU_FTR_CFAR,CPU_FTR_CFAR,947); \
BEGIN_FTR_SECTION_NESTED(948) \
ld r10,area+EX_PPR(r13); \
std r10,HSTATE_PPR(r13); \
END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948); \
ld r10,area+EX_R10(r13); \
std r12,HSTATE_SCRATCH0(r13); \
sldi r12,r9,32; \
ori r12,r12,(n); \
/* This reloads r9 before branching to kvmppc_interrupt */ \
__BRANCH_TO_KVM_EXIT(area, kvmppc_interrupt)
#define __KVM_HANDLER_SKIP(area, h, n) \
cmpwi r10,KVM_GUEST_MODE_SKIP; \
beq 89f; \
BEGIN_FTR_SECTION_NESTED(948) \
ld r10,area+EX_PPR(r13); \
std r10,HSTATE_PPR(r13); \
END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948); \
ld r10,area+EX_R10(r13); \
std r12,HSTATE_SCRATCH0(r13); \
sldi r12,r9,32; \
ori r12,r12,(n); \
/* This reloads r9 before branching to kvmppc_interrupt */ \
__BRANCH_TO_KVM_EXIT(area, kvmppc_interrupt); \
89: mtocrf 0x80,r9; \
ld r9,area+EX_R9(r13); \
ld r10,area+EX_R10(r13); \
b kvmppc_skip_##h##interrupt
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
#define KVMTEST(h, n) __KVMTEST(h, n)
#define KVM_HANDLER(area, h, n) __KVM_HANDLER(area, h, n)
#define KVM_HANDLER_SKIP(area, h, n) __KVM_HANDLER_SKIP(area, h, n)
#else
#define KVMTEST(h, n)
#define KVM_HANDLER(area, h, n)
#define KVM_HANDLER_SKIP(area, h, n)
#endif
#define NOTEST(n)
#define EXCEPTION_PROLOG_COMMON_1() \
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 */ \
/*
* 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,-INT_FRAME_SIZE; /* check if r1 is in userspace */ \
blt+ cr1,3f; /* abort if it is */ \
li r1,(n); /* will be reloaded later */ \
sth r1,PACA_TRAP_SAVE(r13); \
std r3,area+EX_R3(r13); \
addi r3,r13,area; /* r3 -> where regs are saved*/ \
RESTORE_CTR(r1, area); \
b bad_stack; \
3: EXCEPTION_PROLOG_COMMON_1(); \
beq 4f; /* if from kernel mode */ \
ACCOUNT_CPU_USER_ENTRY(r13, r9, r10); \
SAVE_PPR(area, r9); \
4: EXCEPTION_PROLOG_COMMON_2(area) \
beq 5f; /* if from kernel mode */ \
MOVE_PPR_TO_THREAD(r9, r10); \
5: EXCEPTION_PROLOG_COMMON_3(n) \
ACCOUNT_STOLEN_TIME
/* Save original regs values from save area to stack frame. */
#define EXCEPTION_PROLOG_COMMON_2(area) \
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); \
BEGIN_FTR_SECTION_NESTED(66); \
ld r10,area+EX_CFAR(r13); \
std r10,ORIG_GPR3(r1); \
END_FTR_SECTION_NESTED(CPU_FTR_CFAR, CPU_FTR_CFAR, 66); \
GET_CTR(r10, area); \
std r10,_CTR(r1);
#define EXCEPTION_PROLOG_COMMON_3(n) \
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 */ \
mflr r9; /* Get LR, later save to stack */ \
ld r2,PACATOC(r13); /* get kernel TOC into r2 */ \
std r9,_LINK(r1); \
lbz r10,PACAIRQSOFTMASK(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(vec, label) \
EXCEPTION_PROLOG(PACA_EXGEN, label, EXC_STD, KVMTEST_PR, vec);
/* Version of above for when we have to branch out-of-line */
#define __OOL_EXCEPTION(vec, label, hdlr) \
SET_SCRATCH0(r13) \
EXCEPTION_PROLOG_0(PACA_EXGEN) \
b hdlr;
#define STD_EXCEPTION_OOL(vec, label) \
EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_PR, vec); \
EXCEPTION_PROLOG_2(label, EXC_STD)
#define STD_EXCEPTION_HV(loc, vec, label) \
EXCEPTION_PROLOG(PACA_EXGEN, label, EXC_HV, KVMTEST_HV, vec);
#define STD_EXCEPTION_HV_OOL(vec, label) \
EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_HV, vec); \
EXCEPTION_PROLOG_2(label, EXC_HV)
#define STD_RELON_EXCEPTION(loc, vec, label) \
/* No guest interrupts come through here */ \
EXCEPTION_RELON_PROLOG(PACA_EXGEN, label, EXC_STD, NOTEST, vec);
#define STD_RELON_EXCEPTION_OOL(vec, label) \
EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, vec); \
EXCEPTION_PROLOG_2_RELON(label, EXC_STD)
#define STD_RELON_EXCEPTION_HV(loc, vec, label) \
EXCEPTION_RELON_PROLOG(PACA_EXGEN, label, EXC_HV, KVMTEST_HV, vec);
#define STD_RELON_EXCEPTION_HV_OOL(vec, label) \
EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_HV, vec); \
EXCEPTION_PROLOG_2_RELON(label, EXC_HV)
/* This associate vector numbers with bits in paca->irq_happened */
#define SOFTEN_VALUE_0x500 PACA_IRQ_EE
#define SOFTEN_VALUE_0x900 PACA_IRQ_DEC
#define SOFTEN_VALUE_0x980 PACA_IRQ_DEC
#define SOFTEN_VALUE_0xa00 PACA_IRQ_DBELL
#define SOFTEN_VALUE_0xe80 PACA_IRQ_DBELL
#define SOFTEN_VALUE_0xe60 PACA_IRQ_HMI
#define SOFTEN_VALUE_0xea0 PACA_IRQ_EE
#define SOFTEN_VALUE_0xf00 PACA_IRQ_PMI
#define __SOFTEN_TEST(h, vec, bitmask) \
lbz r10,PACAIRQSOFTMASK(r13); \
andi. r10,r10,bitmask; \
li r10,SOFTEN_VALUE_##vec; \
bne masked_##h##interrupt
#define _SOFTEN_TEST(h, vec, bitmask) __SOFTEN_TEST(h, vec, bitmask)
#define SOFTEN_TEST_PR(vec, bitmask) \
KVMTEST(EXC_STD, vec); \
_SOFTEN_TEST(EXC_STD, vec, bitmask)
#define SOFTEN_TEST_HV(vec, bitmask) \
KVMTEST(EXC_HV, vec); \
_SOFTEN_TEST(EXC_HV, vec, bitmask)
#define KVMTEST_PR(vec) \
KVMTEST(EXC_STD, vec)
#define KVMTEST_HV(vec) \
KVMTEST(EXC_HV, vec)
#define SOFTEN_NOTEST_PR(vec, bitmask) _SOFTEN_TEST(EXC_STD, vec, bitmask)
#define SOFTEN_NOTEST_HV(vec, bitmask) _SOFTEN_TEST(EXC_HV, vec, bitmask)
#define __MASKABLE_EXCEPTION(vec, label, h, extra, bitmask) \
SET_SCRATCH0(r13); /* save r13 */ \
EXCEPTION_PROLOG_0(PACA_EXGEN); \
MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, extra, vec, bitmask); \
EXCEPTION_PROLOG_2(label, h);
#define MASKABLE_EXCEPTION(vec, label, bitmask) \
__MASKABLE_EXCEPTION(vec, label, EXC_STD, SOFTEN_TEST_PR, bitmask)
#define MASKABLE_EXCEPTION_OOL(vec, label, bitmask) \
MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_TEST_PR, vec, bitmask);\
EXCEPTION_PROLOG_2(label, EXC_STD)
#define MASKABLE_EXCEPTION_HV(vec, label, bitmask) \
__MASKABLE_EXCEPTION(vec, label, EXC_HV, SOFTEN_TEST_HV, bitmask)
#define MASKABLE_EXCEPTION_HV_OOL(vec, label, bitmask) \
MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_TEST_HV, vec, bitmask);\
EXCEPTION_PROLOG_2(label, EXC_HV)
#define __MASKABLE_RELON_EXCEPTION(vec, label, h, extra, bitmask) \
SET_SCRATCH0(r13); /* save r13 */ \
EXCEPTION_PROLOG_0(PACA_EXGEN); \
MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, extra, vec, bitmask); \
EXCEPTION_PROLOG_2_RELON(label, h)
#define MASKABLE_RELON_EXCEPTION(vec, label, bitmask) \
__MASKABLE_RELON_EXCEPTION(vec, label, EXC_STD, SOFTEN_NOTEST_PR, bitmask)
#define MASKABLE_RELON_EXCEPTION_OOL(vec, label, bitmask) \
MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_NOTEST_PR, vec, bitmask);\
EXCEPTION_PROLOG_2(label, EXC_STD);
#define MASKABLE_RELON_EXCEPTION_HV(vec, label, bitmask) \
__MASKABLE_RELON_EXCEPTION(vec, label, EXC_HV, SOFTEN_TEST_HV, bitmask)
#define MASKABLE_RELON_EXCEPTION_HV_OOL(vec, label, bitmask) \
MASKABLE_EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_TEST_HV, vec, bitmask);\
EXCEPTION_PROLOG_2_RELON(label, EXC_HV)
/*
* Our exception common code can be passed various "additions"
* to specify the behaviour of interrupts, whether to kick the
* runlatch, etc...
*/
/*
* This addition reconciles our actual IRQ state with the various software
* flags that track it. This may call C code.
*/
#define ADD_RECONCILE RECONCILE_IRQ_STATE(r10,r11)
#define ADD_NVGPRS \
bl save_nvgprs
#define RUNLATCH_ON \
BEGIN_FTR_SECTION \
CURRENT_THREAD_INFO(r3, r1); \
ld r4,TI_LOCAL_FLAGS(r3); \
andi. r0,r4,_TLF_RUNLATCH; \
beql ppc64_runlatch_on_trampoline; \
END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
#define EXCEPTION_COMMON(area, trap, label, hdlr, ret, additions) \
EXCEPTION_PROLOG_COMMON(trap, area); \
/* Volatile regs are potentially clobbered here */ \
additions; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
bl hdlr; \
b ret
/*
* Exception where stack is already set in r1, r1 is saved in r10, and it
* continues rather than returns.
*/
#define EXCEPTION_COMMON_NORET_STACK(area, trap, label, hdlr, additions) \
EXCEPTION_PROLOG_COMMON_1(); \
EXCEPTION_PROLOG_COMMON_2(area); \
EXCEPTION_PROLOG_COMMON_3(trap); \
/* Volatile regs are potentially clobbered here */ \
additions; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
bl hdlr
#define STD_EXCEPTION_COMMON(trap, label, hdlr) \
EXCEPTION_COMMON(PACA_EXGEN, trap, label, hdlr, \
ret_from_except, ADD_NVGPRS;ADD_RECONCILE)
/*
* Like STD_EXCEPTION_COMMON, but for exceptions that can occur
* in the idle task and therefore need the special idle handling
* (finish nap and runlatch)
*/
#define STD_EXCEPTION_COMMON_ASYNC(trap, label, hdlr) \
EXCEPTION_COMMON(PACA_EXGEN, trap, label, hdlr, \
ret_from_except_lite, FINISH_NAP;ADD_RECONCILE;RUNLATCH_ON)
/*
* 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 \
CURRENT_THREAD_INFO(r11, r1); \
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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