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powerpc/64s: Implement interrupt exit logic in C

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Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.

The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.

The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.

This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.

mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.

mpe: Incorporate fix from Nick:

The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.

The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2020-02-26 03:35:37 +10:00 committed by Michael Ellerman
parent 3282a3da25
commit 6cc0c16d82
11 changed files with 655 additions and 529 deletions
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2
arch/powerpc/include/asm/asm-prototypes.h
View File

@ -99,6 +99,8 @@ void __init machine_init(u64 dt_ptr);
#endif
long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8, unsigned long r0, struct pt_regs *regs);
notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *regs);
notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr);
notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsigned long msr);
long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
u32 len_high, u32 len_low);

10
arch/powerpc/include/asm/book3s/64/kup-radix.h
View File

@ -60,6 +60,12 @@
#include <asm/mmu.h>
#include <asm/ptrace.h>
static inline void kuap_restore_amr(struct pt_regs *regs)
{
if (mmu_has_feature(MMU_FTR_RADIX_KUAP))
mtspr(SPRN_AMR, regs->kuap);
}
static inline void kuap_check_amr(void)
{
if (IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && mmu_has_feature(MMU_FTR_RADIX_KUAP))
@ -136,6 +142,10 @@ bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
"Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
}
#else /* CONFIG_PPC_KUAP */
static inline void kuap_restore_amr(struct pt_regs *regs)
{
}
static inline void kuap_check_amr(void)
{
}

1
arch/powerpc/include/asm/hw_irq.h
View File

@ -52,6 +52,7 @@
#ifndef __ASSEMBLY__
extern void replay_system_reset(void);
extern void replay_soft_interrupts(void);
extern void timer_interrupt(struct pt_regs *);
extern void timer_broadcast_interrupt(void);

6
arch/powerpc/include/asm/switch_to.h
View File

@ -23,7 +23,13 @@ extern void switch_booke_debug_regs(struct debug_reg *new_debug);
extern int emulate_altivec(struct pt_regs *);
#ifdef CONFIG_PPC_BOOK3S_64
void restore_math(struct pt_regs *regs);
#else
static inline void restore_math(struct pt_regs *regs)
{
}
#endif
void restore_tm_state(struct pt_regs *regs);

493
arch/powerpc/kernel/entry_64.S
View File

@ -16,6 +16,7 @@
#include <linux/errno.h>
#include <linux/err.h>
#include <asm/cache.h>
#include <asm/unistd.h>
#include <asm/processor.h>
#include <asm/page.h>
@ -228,6 +229,7 @@ _GLOBAL(ret_from_kernel_thread)
li r3,0
b .Lsyscall_exit
#ifdef CONFIG_PPC_BOOK3E
/* Save non-volatile GPRs, if not already saved. */
_GLOBAL(save_nvgprs)
ld r11,_TRAP(r1)
@ -238,6 +240,7 @@ _GLOBAL(save_nvgprs)
std r0,_TRAP(r1)
blr
_ASM_NOKPROBE_SYMBOL(save_nvgprs);
#endif
#ifdef CONFIG_PPC_BOOK3S_64
@ -301,7 +304,7 @@ flush_count_cache:
* state of one is saved on its kernel stack. Then the state
* of the other is restored from its kernel stack. The memory
* management hardware is updated to the second process's state.
* Finally, we can return to the second process, via ret_from_except.
* Finally, we can return to the second process, via interrupt_return.
* On entry, r3 points to the THREAD for the current task, r4
* points to the THREAD for the new task.
*
@ -453,408 +456,152 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
addi r1,r1,SWITCH_FRAME_SIZE
blr
.align 7
_GLOBAL(ret_from_except)
ld r11,_TRAP(r1)
andi. r0,r11,1
bne ret_from_except_lite
#ifdef CONFIG_PPC_BOOK3S
/*
* If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not
* touched, AMR not set, no exit work created, then this can be used.
*/
.balign IFETCH_ALIGN_BYTES
.globl fast_interrupt_return
fast_interrupt_return:
_ASM_NOKPROBE_SYMBOL(fast_interrupt_return)
ld r4,_MSR(r1)
andi. r0,r4,MSR_PR
bne .Lfast_user_interrupt_return
andi. r0,r4,MSR_RI
li r3,0 /* 0 return value, no EMULATE_STACK_STORE */
bne+ .Lfast_kernel_interrupt_return
addi r3,r1,STACK_FRAME_OVERHEAD
bl unrecoverable_exception
b . /* should not get here */
.balign IFETCH_ALIGN_BYTES
.globl interrupt_return
interrupt_return:
_ASM_NOKPROBE_SYMBOL(interrupt_return)
REST_NVGPRS(r1)
_GLOBAL(ret_from_except_lite)
/*
* Disable interrupts so that current_thread_info()->flags
* can't change between when we test it and when we return
* from the interrupt.
*/
#ifdef CONFIG_PPC_BOOK3E
wrteei 0
#else
li r10,MSR_RI
mtmsrd r10,1 /* Update machine state */
#endif /* CONFIG_PPC_BOOK3E */
ld r9, PACA_THREAD_INFO(r13)
ld r3,_MSR(r1)
#ifdef CONFIG_PPC_BOOK3E
ld r10,PACACURRENT(r13)
#endif /* CONFIG_PPC_BOOK3E */
ld r4,TI_FLAGS(r9)
andi. r3,r3,MSR_PR
beq resume_kernel
#ifdef CONFIG_PPC_BOOK3E
lwz r3,(THREAD+THREAD_DBCR0)(r10)
#endif /* CONFIG_PPC_BOOK3E */
/* Check current_thread_info()->flags */
andi. r0,r4,_TIF_USER_WORK_MASK
bne 1f
#ifdef CONFIG_PPC_BOOK3E
/*
* Check to see if the dbcr0 register is set up to debug.
* Use the internal debug mode bit to do this.
*/
andis. r0,r3,DBCR0_IDM@h
beq restore
mfmsr r0
rlwinm r0,r0,0,~MSR_DE /* Clear MSR.DE */
mtmsr r0
mtspr SPRN_DBCR0,r3
li r10, -1
mtspr SPRN_DBSR,r10
b restore
#else
.balign IFETCH_ALIGN_BYTES
.globl interrupt_return_lite
interrupt_return_lite:
_ASM_NOKPROBE_SYMBOL(interrupt_return_lite)
ld r4,_MSR(r1)
andi. r0,r4,MSR_PR
beq .Lkernel_interrupt_return
addi r3,r1,STACK_FRAME_OVERHEAD
bl restore_math
b restore
#endif
1: andi. r0,r4,_TIF_NEED_RESCHED
beq 2f
bl restore_interrupts
SCHEDULE_USER
b ret_from_except_lite
2:
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
andi. r0,r4,_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM
bne 3f /* only restore TM if nothing else to do */
addi r3,r1,STACK_FRAME_OVERHEAD
bl restore_tm_state
b restore
3:
#endif
bl save_nvgprs
/*
* Use a non volatile GPR to save and restore our thread_info flags
* across the call to restore_interrupts.
*/
mr r30,r4
bl restore_interrupts
mr r4,r30
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_notify_resume
b ret_from_except
bl interrupt_exit_user_prepare
cmpdi r3,0
bne- .Lrestore_nvgprs
resume_kernel:
/* check current_thread_info, _TIF_EMULATE_STACK_STORE */
andis. r8,r4,_TIF_EMULATE_STACK_STORE@h
beq+ 1f
.Lfast_user_interrupt_return:
ld r11,_NIP(r1)
ld r12,_MSR(r1)
BEGIN_FTR_SECTION
ld r10,_PPR(r1)
mtspr SPRN_PPR,r10
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r12
addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */
ld r3,GPR1(r1)
subi r3,r3,INT_FRAME_SIZE /* dst: Allocate a trampoline exception frame */
mr r4,r1 /* src: current exception frame */
mr r1,r3 /* Reroute the trampoline frame to r1 */
/* Copy from the original to the trampoline. */
li r5,INT_FRAME_SIZE/8 /* size: INT_FRAME_SIZE */
li r6,0 /* start offset: 0 */
mtctr r5
2: ldx r0,r6,r4
stdx r0,r6,r3
addi r6,r6,8
bdnz 2b
/* Do real store operation to complete stdu */
ld r5,GPR1(r1)
std r8,0(r5)
/* Clear _TIF_EMULATE_STACK_STORE flag */
lis r11,_TIF_EMULATE_STACK_STORE@h
addi r5,r9,TI_FLAGS
0: ldarx r4,0,r5
andc r4,r4,r11
stdcx. r4,0,r5
bne- 0b
1:
#ifdef CONFIG_PREEMPTION
/* Check if we need to preempt */
andi. r0,r4,_TIF_NEED_RESCHED
beq+ restore
/* Check that preempt_count() == 0 and interrupts are enabled */
lwz r8,TI_PREEMPT(r9)
cmpwi cr0,r8,0
bne restore
ld r0,SOFTE(r1)
andi. r0,r0,IRQS_DISABLED
bne restore
/*
* Here we are preempting the current task. We want to make
* sure we are soft-disabled first and reconcile irq state.
*/
RECONCILE_IRQ_STATE(r3,r4)
bl preempt_schedule_irq
/*
* arch_local_irq_restore() from preempt_schedule_irq above may
* enable hard interrupt but we really should disable interrupts
* when we return from the interrupt, and so that we don't get
* interrupted after loading SRR0/1.
*/
#ifdef CONFIG_PPC_BOOK3E
wrteei 0
#else
li r10,MSR_RI
mtmsrd r10,1 /* Update machine state */
#endif /* CONFIG_PPC_BOOK3E */
#endif /* CONFIG_PREEMPTION */
.globl fast_exc_return_irq
fast_exc_return_irq:
restore:
/*
* This is the main kernel exit path. First we check if we
* are about to re-enable interrupts
*/
ld r5,SOFTE(r1)
lbz r6,PACAIRQSOFTMASK(r13)
andi. r5,r5,IRQS_DISABLED
bne .Lrestore_irq_off
/* We are enabling, were we already enabled ? Yes, just return */
andi. r6,r6,IRQS_DISABLED
beq cr0,.Ldo_restore
/*
* We are about to soft-enable interrupts (we are hard disabled
* at this point). We check if there's anything that needs to
* be replayed first.
*/
lbz r0,PACAIRQHAPPENED(r13)
cmpwi cr0,r0,0
bne- .Lrestore_check_irq_replay
/*
* Get here when nothing happened while soft-disabled, just
* soft-enable and move-on. We will hard-enable as a side
* effect of rfi
*/
.Lrestore_no_replay:
TRACE_ENABLE_INTS
li r0,IRQS_ENABLED
stb r0,PACAIRQSOFTMASK(r13);
/*
* Final return path. BookE is handled in a different file
*/
.Ldo_restore:
#ifdef CONFIG_PPC_BOOK3E
b exception_return_book3e
#else
/*
* Clear the reservation. If we know the CPU tracks the address of
* the reservation then we can potentially save some cycles and use
* a larx. On POWER6 and POWER7 this is significantly faster.
*/
BEGIN_FTR_SECTION
stdcx. r0,0,r1 /* to clear the reservation */
FTR_SECTION_ELSE
ldarx r4,0,r1
ldarx r0,0,r1
ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
/*
* Some code path such as load_up_fpu or altivec return directly
* here. They run entirely hard disabled and do not alter the
* interrupt state. They also don't use lwarx/stwcx. and thus
* are known not to leave dangling reservations.
*/
.globl fast_exception_return
fast_exception_return:
ld r3,_MSR(r1)
ld r4,_CTR(r1)
ld r0,_LINK(r1)
mtctr r4
mtlr r0
ld r4,_XER(r1)
mtspr SPRN_XER,r4
ld r3,_CCR(r1)
ld r4,_LINK(r1)
ld r5,_CTR(r1)
ld r6,_XER(r1)
li r0,0
kuap_check_amr r5, r6
REST_8GPRS(5, r1)
andi. r0,r3,MSR_RI
beq- .Lunrecov_restore
/*
* Clear RI before restoring r13. If we are returning to
* userspace and we take an exception after restoring r13,
* we end up corrupting the userspace r13 value.
*/
li r4,0
mtmsrd r4,1
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/* TM debug */
std r3, PACATMSCRATCH(r13) /* Stash returned-to MSR */
#endif
/*
* r13 is our per cpu area, only restore it if we are returning to
* userspace the value stored in the stack frame may belong to
* another CPU.
*/
andi. r0,r3,MSR_PR
beq 1f
BEGIN_FTR_SECTION
/* Restore PPR */
ld r2,_PPR(r1)
mtspr SPRN_PPR,r2
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
ACCOUNT_CPU_USER_EXIT(r13, r2, r4)
REST_4GPRS(7, r1)
REST_2GPRS(11, r1)
REST_GPR(13, r1)
/*
* We don't need to restore AMR on the way back to userspace for KUAP.
* The value of AMR only matters while we're in the kernel.
*/
mtspr SPRN_SRR1,r3
mtcr r3
mtlr r4
mtctr r5
mtspr SPRN_XER,r6
ld r2,_CCR(r1)
mtcrf 0xFF,r2
ld r2,_NIP(r1)
mtspr SPRN_SRR0,r2
ld r0,GPR0(r1)
ld r2,GPR2(r1)
ld r3,GPR3(r1)
ld r4,GPR4(r1)
ld r1,GPR1(r1)
REST_4GPRS(2, r1)
REST_GPR(6, r1)
REST_GPR(0, r1)
REST_GPR(1, r1)
RFI_TO_USER
b . /* prevent speculative execution */
1: mtspr SPRN_SRR1,r3
.Lrestore_nvgprs:
REST_NVGPRS(r1)
b .Lfast_user_interrupt_return
ld r2,_CCR(r1)
mtcrf 0xFF,r2
ld r2,_NIP(r1)
mtspr SPRN_SRR0,r2
.balign IFETCH_ALIGN_BYTES
.Lkernel_interrupt_return:
addi r3,r1,STACK_FRAME_OVERHEAD
bl interrupt_exit_kernel_prepare
.Lfast_kernel_interrupt_return:
cmpdi cr1,r3,0
ld r11,_NIP(r1)
ld r12,_MSR(r1)
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r12
BEGIN_FTR_SECTION
stdcx. r0,0,r1 /* to clear the reservation */
FTR_SECTION_ELSE
ldarx r0,0,r1
ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
ld r3,_LINK(r1)
ld r4,_CTR(r1)
ld r5,_XER(r1)
ld r6,_CCR(r1)
li r0,0
REST_4GPRS(7, r1)
REST_2GPRS(11, r1)
mtlr r3
mtctr r4
mtspr SPRN_XER,r5
/*
* Leaving a stale exception_marker on the stack can confuse
* the reliable stack unwinder later on. Clear it.
*/
li r2,0
std r2,STACK_FRAME_OVERHEAD-16(r1)
std r0,STACK_FRAME_OVERHEAD-16(r1)
ld r0,GPR0(r1)
ld r2,GPR2(r1)
ld r3,GPR3(r1)
REST_4GPRS(2, r1)
kuap_restore_amr r4
ld r4,GPR4(r1)
ld r1,GPR1(r1)
bne- cr1,1f /* emulate stack store */
mtcr r6
REST_GPR(6, r1)
REST_GPR(0, r1)
REST_GPR(1, r1)
RFI_TO_KERNEL
b . /* prevent speculative execution */
#endif /* CONFIG_PPC_BOOK3E */
/*
* We are returning to a context with interrupts soft disabled.
*
* However, we may also about to hard enable, so we need to
* make sure that in this case, we also clear PACA_IRQ_HARD_DIS
* or that bit can get out of sync and bad things will happen
1: /*
* Emulate stack store with update. New r1 value was already calculated
* and updated in our interrupt regs by emulate_loadstore, but we can't
* store the previous value of r1 to the stack before re-loading our
* registers from it, otherwise they could be clobbered. Use
* PACA_EXGEN as temporary storage to hold the store data, as
* interrupts are disabled here so it won't be clobbered.
*/
.Lrestore_irq_off:
ld r3,_MSR(r1)
lbz r7,PACAIRQHAPPENED(r13)
andi. r0,r3,MSR_EE
beq 1f
rlwinm r7,r7,0,~PACA_IRQ_HARD_DIS
stb r7,PACAIRQHAPPENED(r13)
1:
#if defined(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG) && defined(CONFIG_BUG)
/* The interrupt should not have soft enabled. */
lbz r7,PACAIRQSOFTMASK(r13)
1: tdeqi r7,IRQS_ENABLED
EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
#endif
b .Ldo_restore
/*
* Something did happen, check if a re-emit is needed
* (this also clears paca->irq_happened)
*/
.Lrestore_check_irq_replay:
/* XXX: We could implement a fast path here where we check
* for irq_happened being just 0x01, in which case we can
* clear it and return. That means that we would potentially
* miss a decrementer having wrapped all the way around.
*
* Still, this might be useful for things like hash_page
*/
bl __check_irq_replay
cmpwi cr0,r3,0
beq .Lrestore_no_replay
/*
* We need to re-emit an interrupt. We do so by re-using our
* existing exception frame. We first change the trap value,
* but we need to ensure we preserve the low nibble of it
*/
ld r4,_TRAP(r1)
clrldi r4,r4,60
or r4,r4,r3
std r4,_TRAP(r1)
/*
* PACA_IRQ_HARD_DIS won't always be set here, so set it now
* to reconcile the IRQ state. Tracing is already accounted for.
*/
lbz r4,PACAIRQHAPPENED(r13)
ori r4,r4,PACA_IRQ_HARD_DIS
stb r4,PACAIRQHAPPENED(r13)
/*
* Then find the right handler and call it. Interrupts are
* still soft-disabled and we keep them that way.
*/
cmpwi cr0,r3,0x500
bne 1f
addi r3,r1,STACK_FRAME_OVERHEAD;
bl do_IRQ
b ret_from_except
1: cmpwi cr0,r3,0xf00
bne 1f
addi r3,r1,STACK_FRAME_OVERHEAD;
bl performance_monitor_exception
b ret_from_except
1: cmpwi cr0,r3,0xe60
bne 1f
addi r3,r1,STACK_FRAME_OVERHEAD;
bl handle_hmi_exception
b ret_from_except
1: cmpwi cr0,r3,0x900
bne 1f
addi r3,r1,STACK_FRAME_OVERHEAD;
bl timer_interrupt
b ret_from_except
#ifdef CONFIG_PPC_DOORBELL
1:
#ifdef CONFIG_PPC_BOOK3E
cmpwi cr0,r3,0x280
#else
cmpwi cr0,r3,0xa00
#endif /* CONFIG_PPC_BOOK3E */
bne 1f
addi r3,r1,STACK_FRAME_OVERHEAD;
bl doorbell_exception
#endif /* CONFIG_PPC_DOORBELL */
1: b ret_from_except /* What else to do here ? */
.Lunrecov_restore:
addi r3,r1,STACK_FRAME_OVERHEAD
bl unrecoverable_exception
b .Lunrecov_restore
_ASM_NOKPROBE_SYMBOL(ret_from_except);
_ASM_NOKPROBE_SYMBOL(ret_from_except_lite);
_ASM_NOKPROBE_SYMBOL(resume_kernel);
_ASM_NOKPROBE_SYMBOL(fast_exc_return_irq);
_ASM_NOKPROBE_SYMBOL(restore);
_ASM_NOKPROBE_SYMBOL(fast_exception_return);
mtcr r6
std r9,PACA_EXGEN+0(r13)
addi r9,r1,INT_FRAME_SIZE /* get original r1 */
REST_GPR(6, r1)
REST_GPR(0, r1)
REST_GPR(1, r1)
std r9,0(r1) /* perform store component of stdu */
ld r9,PACA_EXGEN+0(r13)
RFI_TO_KERNEL
b . /* prevent speculative execution */
#endif /* CONFIG_PPC_BOOK3S */
#ifdef CONFIG_PPC_RTAS
/*

255
arch/powerpc/kernel/exceptions-64e.S
View File

@ -24,6 +24,7 @@
#include <asm/kvm_asm.h>
#include <asm/kvm_booke_hv_asm.h>
#include <asm/feature-fixups.h>
#include <asm/context_tracking.h>
/* XXX This will ultimately add space for a special exception save
* structure used to save things like SRR0/SRR1, SPRGs, MAS, etc...
@ -1041,17 +1042,161 @@ alignment_more:
bl alignment_exception
b ret_from_except
/*
* We branch here from entry_64.S for the last stage of the exception
* return code path. MSR:EE is expected to be off at that point
*/
_GLOBAL(exception_return_book3e)
b 1f
.align 7
_GLOBAL(ret_from_except)
ld r11,_TRAP(r1)
andi. r0,r11,1
bne ret_from_except_lite
REST_NVGPRS(r1)
_GLOBAL(ret_from_except_lite)
/*
* Disable interrupts so that current_thread_info()->flags
* can't change between when we test it and when we return
* from the interrupt.
*/
wrteei 0
ld r9, PACA_THREAD_INFO(r13)
ld r3,_MSR(r1)
ld r10,PACACURRENT(r13)
ld r4,TI_FLAGS(r9)
andi. r3,r3,MSR_PR
beq resume_kernel
lwz r3,(THREAD+THREAD_DBCR0)(r10)
/* Check current_thread_info()->flags */
andi. r0,r4,_TIF_USER_WORK_MASK
bne 1f
/*
* Check to see if the dbcr0 register is set up to debug.
* Use the internal debug mode bit to do this.
*/
andis. r0,r3,DBCR0_IDM@h
beq restore
mfmsr r0
rlwinm r0,r0,0,~MSR_DE /* Clear MSR.DE */
mtmsr r0
mtspr SPRN_DBCR0,r3
li r10, -1
mtspr SPRN_DBSR,r10
b restore
1: andi. r0,r4,_TIF_NEED_RESCHED
beq 2f
bl restore_interrupts
SCHEDULE_USER
b ret_from_except_lite
2:
bl save_nvgprs
/*
* Use a non volatile GPR to save and restore our thread_info flags
* across the call to restore_interrupts.
*/
mr r30,r4
bl restore_interrupts
mr r4,r30
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_notify_resume
b ret_from_except
resume_kernel:
/* check current_thread_info, _TIF_EMULATE_STACK_STORE */
andis. r8,r4,_TIF_EMULATE_STACK_STORE@h
beq+ 1f
addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */
ld r3,GPR1(r1)
subi r3,r3,INT_FRAME_SIZE /* dst: Allocate a trampoline exception frame */
mr r4,r1 /* src: current exception frame */
mr r1,r3 /* Reroute the trampoline frame to r1 */
/* Copy from the original to the trampoline. */
li r5,INT_FRAME_SIZE/8 /* size: INT_FRAME_SIZE */
li r6,0 /* start offset: 0 */
mtctr r5
2: ldx r0,r6,r4
stdx r0,r6,r3
addi r6,r6,8
bdnz 2b
/* Do real store operation to complete stdu */
ld r5,GPR1(r1)
std r8,0(r5)
/* Clear _TIF_EMULATE_STACK_STORE flag */
lis r11,_TIF_EMULATE_STACK_STORE@h
addi r5,r9,TI_FLAGS
0: ldarx r4,0,r5
andc r4,r4,r11
stdcx. r4,0,r5
bne- 0b
1:
#ifdef CONFIG_PREEMPT
/* Check if we need to preempt */
andi. r0,r4,_TIF_NEED_RESCHED
beq+ restore
/* Check that preempt_count() == 0 and interrupts are enabled */
lwz r8,TI_PREEMPT(r9)
cmpwi cr0,r8,0
bne restore
ld r0,SOFTE(r1)
andi. r0,r0,IRQS_DISABLED
bne restore
/*
* Here we are preempting the current task. We want to make
* sure we are soft-disabled first and reconcile irq state.
*/
RECONCILE_IRQ_STATE(r3,r4)
bl preempt_schedule_irq
/*
* arch_local_irq_restore() from preempt_schedule_irq above may
* enable hard interrupt but we really should disable interrupts
* when we return from the interrupt, and so that we don't get
* interrupted after loading SRR0/1.
*/
wrteei 0
#endif /* CONFIG_PREEMPT */
restore:
/*
* This is the main kernel exit path. First we check if we
* are about to re-enable interrupts
*/
ld r5,SOFTE(r1)
lbz r6,PACAIRQSOFTMASK(r13)
andi. r5,r5,IRQS_DISABLED
bne .Lrestore_irq_off
/* We are enabling, were we already enabled ? Yes, just return */
andi. r6,r6,IRQS_DISABLED
beq cr0,fast_exception_return
/*
* We are about to soft-enable interrupts (we are hard disabled
* at this point). We check if there's anything that needs to
* be replayed first.
*/
lbz r0,PACAIRQHAPPENED(r13)
cmpwi cr0,r0,0
bne- .Lrestore_check_irq_replay
/*
* Get here when nothing happened while soft-disabled, just
* soft-enable and move-on. We will hard-enable as a side
* effect of rfi
*/
.Lrestore_no_replay:
TRACE_ENABLE_INTS
li r0,IRQS_ENABLED
stb r0,PACAIRQSOFTMASK(r13);
/* This is the return from load_up_fpu fast path which could do with
* less GPR restores in fact, but for now we have a single return path
*/
.globl fast_exception_return
fast_exception_return:
wrteei 0
1: mr r0,r13
@ -1092,6 +1237,102 @@ fast_exception_return:
mfspr r13,SPRN_SPRG_GEN_SCRATCH
rfi
/*
* We are returning to a context with interrupts soft disabled.
*
* However, we may also about to hard enable, so we need to
* make sure that in this case, we also clear PACA_IRQ_HARD_DIS
* or that bit can get out of sync and bad things will happen
*/
.Lrestore_irq_off:
ld r3,_MSR(r1)
lbz r7,PACAIRQHAPPENED(r13)
andi. r0,r3,MSR_EE
beq 1f
rlwinm r7,r7,0,~PACA_IRQ_HARD_DIS
stb r7,PACAIRQHAPPENED(r13)
1:
#if defined(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG) && defined(CONFIG_BUG)
/* The interrupt should not have soft enabled. */
lbz r7,PACAIRQSOFTMASK(r13)
1: tdeqi r7,IRQS_ENABLED
EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
#endif
b fast_exception_return
/*
* Something did happen, check if a re-emit is needed
* (this also clears paca->irq_happened)
*/
.Lrestore_check_irq_replay:
/* XXX: We could implement a fast path here where we check
* for irq_happened being just 0x01, in which case we can
* clear it and return. That means that we would potentially
* miss a decrementer having wrapped all the way around.
*
* Still, this might be useful for things like hash_page
*/
bl __check_irq_replay
cmpwi cr0,r3,0
beq .Lrestore_no_replay
/*
* We need to re-emit an interrupt. We do so by re-using our
* existing exception frame. We first change the trap value,
* but we need to ensure we preserve the low nibble of it
*/
ld r4,_TRAP(r1)
clrldi r4,r4,60
or r4,r4,r3
std r4,_TRAP(r1)
/*
* PACA_IRQ_HARD_DIS won't always be set here, so set it now
* to reconcile the IRQ state. Tracing is already accounted for.
*/
lbz r4,PACAIRQHAPPENED(r13)
ori r4,r4,PACA_IRQ_HARD_DIS
stb r4,PACAIRQHAPPENED(r13)
/*
* Then find the right handler and call it. Interrupts are
* still soft-disabled and we keep them that way.
*/
cmpwi cr0,r3,0x500
bne 1f
addi r3,r1,STACK_FRAME_OVERHEAD;
bl do_IRQ
b ret_from_except
1: cmpwi cr0,r3,0xf00
bne 1f
addi r3,r1,STACK_FRAME_OVERHEAD;
bl performance_monitor_exception
b ret_from_except
1: cmpwi cr0,r3,0xe60
bne 1f
addi r3,r1,STACK_FRAME_OVERHEAD;
bl handle_hmi_exception
b ret_from_except
1: cmpwi cr0,r3,0x900
bne 1f
addi r3,r1,STACK_FRAME_OVERHEAD;
bl timer_interrupt
b ret_from_except
#ifdef CONFIG_PPC_DOORBELL
1:
cmpwi cr0,r3,0x280
bne 1f
addi r3,r1,STACK_FRAME_OVERHEAD;
bl doorbell_exception
#endif /* CONFIG_PPC_DOORBELL */
1: b ret_from_except /* What else to do here ? */
_ASM_NOKPROBE_SYMBOL(ret_from_except);
_ASM_NOKPROBE_SYMBOL(ret_from_except_lite);
_ASM_NOKPROBE_SYMBOL(resume_kernel);
_ASM_NOKPROBE_SYMBOL(restore);
_ASM_NOKPROBE_SYMBOL(fast_exception_return);
/*
* Trampolines used when spotting a bad kernel stack pointer in
* the exception entry code.

119
arch/powerpc/kernel/exceptions-64s.S
View File

@ -589,6 +589,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
std r10,GPR12(r1)
std r11,GPR13(r1)
SAVE_NVGPRS(r1)
.if IDAR
.if IISIDE
ld r10,_NIP(r1)
@ -625,7 +627,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
mfspr r11,SPRN_XER /* save XER in stackframe */
std r10,SOFTE(r1)
std r11,_XER(r1)
li r9,(IVEC)+1
li r9,IVEC
std r9,_TRAP(r1) /* set trap number */
li r10,0
ld r11,exception_marker@toc(r2)
@ -932,7 +934,6 @@ EXC_COMMON_BEGIN(system_reset_common)
ld r1,PACA_NMI_EMERG_SP(r13)
subi r1,r1,INT_FRAME_SIZE
__GEN_COMMON_BODY system_reset
bl save_nvgprs
/*
* Set IRQS_ALL_DISABLED unconditionally so irqs_disabled() does
* the right thing. We do not want to reconcile because that goes
@ -1115,7 +1116,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
li r10,MSR_RI
mtmsrd r10,1
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl machine_check_early
std r3,RESULT(r1) /* Save result */
@ -1208,10 +1208,9 @@ EXC_COMMON_BEGIN(machine_check_common)
/* Enable MSR_RI when finished with PACA_EXMC */
li r10,MSR_RI
mtmsrd r10,1
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl machine_check_exception
b ret_from_except
b interrupt_return
GEN_KVM machine_check
@ -1378,20 +1377,19 @@ BEGIN_MMU_FTR_SECTION
bl do_slb_fault
cmpdi r3,0
bne- 1f
b fast_exception_return
b fast_interrupt_return
1: /* Error case */
MMU_FTR_SECTION_ELSE
/* Radix case, access is outside page table range */
li r3,-EFAULT
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
std r3,RESULT(r1)
bl save_nvgprs
RECONCILE_IRQ_STATE(r10, r11)
ld r4,_DAR(r1)
ld r5,RESULT(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_bad_slb_fault
b ret_from_except
b interrupt_return
GEN_KVM data_access_slb
@ -1471,20 +1469,19 @@ BEGIN_MMU_FTR_SECTION
bl do_slb_fault
cmpdi r3,0
bne- 1f
b fast_exception_return
b fast_interrupt_return
1: /* Error case */
MMU_FTR_SECTION_ELSE
/* Radix case, access is outside page table range */
li r3,-EFAULT
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
std r3,RESULT(r1)
bl save_nvgprs
RECONCILE_IRQ_STATE(r10, r11)
ld r4,_DAR(r1)
ld r5,RESULT(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_bad_slb_fault
b ret_from_except
b interrupt_return
GEN_KVM instruction_access_slb
@ -1532,7 +1529,7 @@ EXC_COMMON_BEGIN(hardware_interrupt_common)
RUNLATCH_ON
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_IRQ
b ret_from_except_lite
b interrupt_return_lite
GEN_KVM hardware_interrupt
@ -1558,10 +1555,9 @@ EXC_VIRT_BEGIN(alignment, 0x4600, 0x100)
EXC_VIRT_END(alignment, 0x4600, 0x100)
EXC_COMMON_BEGIN(alignment_common)
GEN_COMMON alignment
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl alignment_exception
b ret_from_except
b interrupt_return
GEN_KVM alignment
@ -1622,10 +1618,9 @@ EXC_COMMON_BEGIN(program_check_common)
__ISTACK(program_check)=1
__GEN_COMMON_BODY program_check
3:
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl program_check_exception
b ret_from_except
b interrupt_return
GEN_KVM program_check
@ -1656,7 +1651,6 @@ EXC_VIRT_END(fp_unavailable, 0x4800, 0x100)
EXC_COMMON_BEGIN(fp_unavailable_common)
GEN_COMMON fp_unavailable
bne 1f /* if from user, just load it up */
bl save_nvgprs
RECONCILE_IRQ_STATE(r10, r11)
addi r3,r1,STACK_FRAME_OVERHEAD
bl kernel_fp_unavailable_exception
@ -1673,14 +1667,13 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_TM)
#endif
bl load_up_fpu
b fast_exception_return
b fast_interrupt_return
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2: /* User process was in a transaction */
bl save_nvgprs
RECONCILE_IRQ_STATE(r10, r11)
addi r3,r1,STACK_FRAME_OVERHEAD
bl fp_unavailable_tm
b ret_from_except
b interrupt_return
#endif
GEN_KVM fp_unavailable
@ -1723,7 +1716,7 @@ EXC_COMMON_BEGIN(decrementer_common)
RUNLATCH_ON
addi r3,r1,STACK_FRAME_OVERHEAD
bl timer_interrupt
b ret_from_except_lite
b interrupt_return_lite
GEN_KVM decrementer
@ -1814,7 +1807,7 @@ EXC_COMMON_BEGIN(doorbell_super_common)
#else
bl unknown_exception
#endif
b ret_from_except_lite
b interrupt_return_lite
GEN_KVM doorbell_super
@ -1986,10 +1979,9 @@ EXC_VIRT_BEGIN(single_step, 0x4d00, 0x100)
EXC_VIRT_END(single_step, 0x4d00, 0x100)
EXC_COMMON_BEGIN(single_step_common)
GEN_COMMON single_step
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl single_step_exception
b ret_from_except
b interrupt_return
GEN_KVM single_step
@ -2024,7 +2016,6 @@ EXC_VIRT_BEGIN(h_data_storage, 0x4e00, 0x20)
EXC_VIRT_END(h_data_storage, 0x4e00, 0x20)
EXC_COMMON_BEGIN(h_data_storage_common)
GEN_COMMON h_data_storage
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
BEGIN_MMU_FTR_SECTION
ld r4,_DAR(r1)
@ -2033,7 +2024,7 @@ BEGIN_MMU_FTR_SECTION
MMU_FTR_SECTION_ELSE
bl unknown_exception
ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX)
b ret_from_except
b interrupt_return
GEN_KVM h_data_storage
@ -2058,10 +2049,9 @@ EXC_VIRT_BEGIN(h_instr_storage, 0x4e20, 0x20)
EXC_VIRT_END(h_instr_storage, 0x4e20, 0x20)
EXC_COMMON_BEGIN(h_instr_storage_common)
GEN_COMMON h_instr_storage
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl unknown_exception
b ret_from_except
b interrupt_return
GEN_KVM h_instr_storage
@ -2084,10 +2074,9 @@ EXC_VIRT_BEGIN(emulation_assist, 0x4e40, 0x20)
EXC_VIRT_END(emulation_assist, 0x4e40, 0x20)
EXC_COMMON_BEGIN(emulation_assist_common)
GEN_COMMON emulation_assist
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl emulation_assist_interrupt
b ret_from_except
b interrupt_return
GEN_KVM emulation_assist
@ -2169,10 +2158,9 @@ EXC_COMMON_BEGIN(hmi_exception_common)
GEN_COMMON hmi_exception
FINISH_NAP
RUNLATCH_ON
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl handle_hmi_exception
b ret_from_except
b interrupt_return
GEN_KVM hmi_exception
@ -2206,7 +2194,7 @@ EXC_COMMON_BEGIN(h_doorbell_common)
#else
bl unknown_exception
#endif
b ret_from_except_lite
b interrupt_return_lite
GEN_KVM h_doorbell
@ -2236,7 +2224,7 @@ EXC_COMMON_BEGIN(h_virt_irq_common)
RUNLATCH_ON
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_IRQ
b ret_from_except_lite
b interrupt_return_lite
GEN_KVM h_virt_irq
@ -2283,7 +2271,7 @@ EXC_COMMON_BEGIN(performance_monitor_common)
RUNLATCH_ON
addi r3,r1,STACK_FRAME_OVERHEAD
bl performance_monitor_exception
b ret_from_except_lite
b interrupt_return_lite
GEN_KVM performance_monitor
@ -2323,23 +2311,21 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
#endif
bl load_up_altivec
b fast_exception_return
b fast_interrupt_return
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2: /* User process was in a transaction */
bl save_nvgprs
RECONCILE_IRQ_STATE(r10, r11)
addi r3,r1,STACK_FRAME_OVERHEAD
bl altivec_unavailable_tm
b ret_from_except
b interrupt_return
#endif
1:
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
bl save_nvgprs
RECONCILE_IRQ_STATE(r10, r11)
addi r3,r1,STACK_FRAME_OVERHEAD
bl altivec_unavailable_exception
b ret_from_except
b interrupt_return
GEN_KVM altivec_unavailable
@ -2381,20 +2367,18 @@ BEGIN_FTR_SECTION
b load_up_vsx
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2: /* User process was in a transaction */
bl save_nvgprs
RECONCILE_IRQ_STATE(r10, r11)
addi r3,r1,STACK_FRAME_OVERHEAD
bl vsx_unavailable_tm
b ret_from_except
b interrupt_return
#endif
1:
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif
bl save_nvgprs
RECONCILE_IRQ_STATE(r10, r11)
addi r3,r1,STACK_FRAME_OVERHEAD
bl vsx_unavailable_exception
b ret_from_except
b interrupt_return
GEN_KVM vsx_unavailable
@ -2421,10 +2405,9 @@ EXC_VIRT_BEGIN(facility_unavailable, 0x4f60, 0x20)
EXC_VIRT_END(facility_unavailable, 0x4f60, 0x20)
EXC_COMMON_BEGIN(facility_unavailable_common)
GEN_COMMON facility_unavailable
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl facility_unavailable_exception
b ret_from_except
b interrupt_return
GEN_KVM facility_unavailable
@ -2451,10 +2434,9 @@ EXC_VIRT_BEGIN(h_facility_unavailable, 0x4f80, 0x20)
EXC_VIRT_END(h_facility_unavailable, 0x4f80, 0x20)
EXC_COMMON_BEGIN(h_facility_unavailable_common)
GEN_COMMON h_facility_unavailable
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl facility_unavailable_exception
b ret_from_except
b interrupt_return
GEN_KVM h_facility_unavailable
@ -2485,10 +2467,9 @@ EXC_REAL_END(cbe_system_error, 0x1200, 0x100)
EXC_VIRT_NONE(0x5200, 0x100)
EXC_COMMON_BEGIN(cbe_system_error_common)
GEN_COMMON cbe_system_error
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl cbe_system_error_exception
b ret_from_except
b interrupt_return
GEN_KVM cbe_system_error
@ -2514,10 +2495,9 @@ EXC_VIRT_BEGIN(instruction_breakpoint, 0x5300, 0x100)
EXC_VIRT_END(instruction_breakpoint, 0x5300, 0x100)
EXC_COMMON_BEGIN(instruction_breakpoint_common)
GEN_COMMON instruction_breakpoint
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl instruction_breakpoint_exception
b ret_from_except
b interrupt_return
GEN_KVM instruction_breakpoint
@ -2637,10 +2617,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
EXC_COMMON_BEGIN(denorm_exception_common)
GEN_COMMON denorm_exception
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl unknown_exception
b ret_from_except
b interrupt_return
GEN_KVM denorm_exception
@ -2659,10 +2638,9 @@ EXC_REAL_END(cbe_maintenance, 0x1600, 0x100)
EXC_VIRT_NONE(0x5600, 0x100)
EXC_COMMON_BEGIN(cbe_maintenance_common)
GEN_COMMON cbe_maintenance
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl cbe_maintenance_exception
b ret_from_except
b interrupt_return
GEN_KVM cbe_maintenance
@ -2687,14 +2665,13 @@ EXC_VIRT_BEGIN(altivec_assist, 0x5700, 0x100)
EXC_VIRT_END(altivec_assist, 0x5700, 0x100)
EXC_COMMON_BEGIN(altivec_assist_common)
GEN_COMMON altivec_assist
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_ALTIVEC
bl altivec_assist_exception
#else
bl unknown_exception
#endif
b ret_from_except
b interrupt_return
GEN_KVM altivec_assist
@ -2713,10 +2690,9 @@ EXC_REAL_END(cbe_thermal, 0x1800, 0x100)
EXC_VIRT_NONE(0x5800, 0x100)
EXC_COMMON_BEGIN(cbe_thermal_common)
GEN_COMMON cbe_thermal
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl cbe_thermal_exception
b ret_from_except
b interrupt_return
GEN_KVM cbe_thermal
@ -2749,7 +2725,6 @@ EXC_COMMON_BEGIN(soft_nmi_common)
ld r1,PACAEMERGSP(r13)
subi r1,r1,INT_FRAME_SIZE
__GEN_COMMON_BODY soft_nmi
bl save_nvgprs
/*
* Set IRQS_ALL_DISABLED and save PACAIRQHAPPENED (see
@ -3082,7 +3057,7 @@ do_hash_page:
cmpdi r3,0 /* see if __hash_page succeeded */
/* Success */
beq fast_exc_return_irq /* Return from exception on success */
beq interrupt_return_lite /* Return from exception on success */
/* Error */
blt- 13f
@ -3099,17 +3074,15 @@ handle_page_fault:
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_page_fault
cmpdi r3,0
beq+ ret_from_except_lite
bl save_nvgprs
beq+ interrupt_return_lite
mr r5,r3
addi r3,r1,STACK_FRAME_OVERHEAD
ld r4,_DAR(r1)
bl bad_page_fault
b ret_from_except
b interrupt_return
/* We have a data breakpoint exception - handle it */
handle_dabr_fault:
bl save_nvgprs
ld r4,_DAR(r1)
ld r5,_DSISR(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
@ -3117,21 +3090,20 @@ handle_dabr_fault:
/*
* do_break() may have changed the NV GPRS while handling a breakpoint.
* If so, we need to restore them with their updated values. Don't use
* ret_from_except_lite here.
* interrupt_return_lite here.
*/
b ret_from_except
b interrupt_return
#ifdef CONFIG_PPC_BOOK3S_64
/* We have a page fault that hash_page could handle but HV refused
* the PTE insertion
*/
13: bl save_nvgprs
mr r5,r3
13: mr r5,r3
addi r3,r1,STACK_FRAME_OVERHEAD
ld r4,_DAR(r1)
bl low_hash_fault
b ret_from_except
b interrupt_return
#endif
/*
@ -3141,11 +3113,10 @@ handle_dabr_fault:
* were soft-disabled. We want to invoke the exception handler for
* the access, or panic if there isn't a handler.
*/
77: bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
77: addi r3,r1,STACK_FRAME_OVERHEAD
li r5,SIGSEGV
bl bad_page_fault
b ret_from_except
b interrupt_return
/*
* When doorbell is triggered from system reset wakeup, the message is

36
arch/powerpc/kernel/irq.c
View File

@ -110,6 +110,8 @@ static inline notrace int decrementer_check_overflow(void)
return now >= *next_tb;
}
#ifdef CONFIG_PPC_BOOK3E
/* This is called whenever we are re-enabling interrupts
* and returns either 0 (nothing to do) or 500/900/280/a00/e80 if
* there's an EE, DEC or DBELL to generate.
@ -169,41 +171,16 @@ notrace unsigned int __check_irq_replay(void)
}
}
/*
* Force the delivery of pending soft-disabled interrupts on PS3.
* Any HV call will have this side effect.
*/
if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
u64 tmp, tmp2;
lv1_get_version_info(&tmp, &tmp2);
}
/*
* Check if an hypervisor Maintenance interrupt happened.
* This is a higher priority interrupt than the others, so
* replay it first.
*/
if (happened & PACA_IRQ_HMI) {
local_paca->irq_happened &= ~PACA_IRQ_HMI;
return 0xe60;
}
if (happened & PACA_IRQ_DEC) {
local_paca->irq_happened &= ~PACA_IRQ_DEC;
return 0x900;
}
if (happened & PACA_IRQ_PMI) {
local_paca->irq_happened &= ~PACA_IRQ_PMI;
return 0xf00;
}
if (happened & PACA_IRQ_EE) {
local_paca->irq_happened &= ~PACA_IRQ_EE;
return 0x500;
}
#ifdef CONFIG_PPC_BOOK3E
/*
* Check if an EPR external interrupt happened this bit is typically
* set if we need to handle another "edge" interrupt from within the
@ -218,20 +195,15 @@ notrace unsigned int __check_irq_replay(void)
local_paca->irq_happened &= ~PACA_IRQ_DBELL;
return 0x280;
}
#else
if (happened & PACA_IRQ_DBELL) {
local_paca->irq_happened &= ~PACA_IRQ_DBELL;
return 0xa00;
}
#endif /* CONFIG_PPC_BOOK3E */
/* There should be nothing left ! */
BUG_ON(local_paca->irq_happened != 0);
return 0;
}
#endif /* CONFIG_PPC_BOOK3E */
static void replay_soft_interrupts(void)
void replay_soft_interrupts(void)
{
/*
* We use local_paca rather than get_paca() to avoid all

89
arch/powerpc/kernel/process.c
View File

@ -236,23 +236,9 @@ void enable_kernel_fp(void)
}
}
EXPORT_SYMBOL(enable_kernel_fp);
static int restore_fp(struct task_struct *tsk)
{
if (tsk->thread.load_fp) {
load_fp_state(&current->thread.fp_state);
current->thread.load_fp++;
return 1;
}
return 0;
}
#else
static int restore_fp(struct task_struct *tsk) { return 0; }
#endif /* CONFIG_PPC_FPU */
#ifdef CONFIG_ALTIVEC
#define loadvec(thr) ((thr).load_vec)
static void __giveup_altivec(struct task_struct *tsk)
{
unsigned long msr;
@ -318,21 +304,6 @@ void flush_altivec_to_thread(struct task_struct *tsk)
}
}
EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
static int restore_altivec(struct task_struct *tsk)
{
if (cpu_has_feature(CPU_FTR_ALTIVEC) && (tsk->thread.load_vec)) {
load_vr_state(&tsk->thread.vr_state);
tsk->thread.used_vr = 1;
tsk->thread.load_vec++;
return 1;
}
return 0;
}
#else
#define loadvec(thr) 0
static inline int restore_altivec(struct task_struct *tsk) { return 0; }
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_VSX
@ -400,18 +371,6 @@ void flush_vsx_to_thread(struct task_struct *tsk)
}
}
EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
static int restore_vsx(struct task_struct *tsk)
{
if (cpu_has_feature(CPU_FTR_VSX)) {
tsk->thread.used_vsr = 1;
return 1;
}
return 0;
}
#else
static inline int restore_vsx(struct task_struct *tsk) { return 0; }
#endif /* CONFIG_VSX */
#ifdef CONFIG_SPE
@ -511,6 +470,53 @@ void giveup_all(struct task_struct *tsk)
}
EXPORT_SYMBOL(giveup_all);
#ifdef CONFIG_PPC_BOOK3S_64
#ifdef CONFIG_PPC_FPU
static int restore_fp(struct task_struct *tsk)
{
if (tsk->thread.load_fp) {
load_fp_state(&current->thread.fp_state);
current->thread.load_fp++;
return 1;
}
return 0;
}
#else
static int restore_fp(struct task_struct *tsk) { return 0; }
#endif /* CONFIG_PPC_FPU */
#ifdef CONFIG_ALTIVEC
#define loadvec(thr) ((thr).load_vec)
static int restore_altivec(struct task_struct *tsk)
{
if (cpu_has_feature(CPU_FTR_ALTIVEC) && (tsk->thread.load_vec)) {
load_vr_state(&tsk->thread.vr_state);
tsk->thread.used_vr = 1;
tsk->thread.load_vec++;
return 1;
}
return 0;
}
#else
#define loadvec(thr) 0
static inline int restore_altivec(struct task_struct *tsk) { return 0; }
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_VSX
static int restore_vsx(struct task_struct *tsk)
{
if (cpu_has_feature(CPU_FTR_VSX)) {
tsk->thread.used_vsr = 1;
return 1;
}
return 0;
}
#else
static inline int restore_vsx(struct task_struct *tsk) { return 0; }
#endif /* CONFIG_VSX */
/*
* The exception exit path calls restore_math() with interrupts hard disabled
* but the soft irq state not "reconciled". ftrace code that calls
@ -551,6 +557,7 @@ void notrace restore_math(struct pt_regs *regs)
regs->msr = msr;
}
#endif
static void save_all(struct task_struct *tsk)
{

171
arch/powerpc/kernel/syscall_64.c
View File

@ -24,7 +24,11 @@ notrace long system_call_exception(long r3, long r4, long r5, long r6, long r7,
unsigned long ti_flags;
syscall_fn f;
if (IS_ENABLED(CONFIG_PPC_BOOK3S))
BUG_ON(!(regs->msr & MSR_RI));
BUG_ON(!(regs->msr & MSR_PR));
BUG_ON(!FULL_REGS(regs));
BUG_ON(regs->softe != IRQS_ENABLED);
account_cpu_user_entry();
@ -196,7 +200,7 @@ again:
trace_hardirqs_off();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
local_irq_enable();
/* Took an interrupt which may have more exit work to do. */
/* Took an interrupt, may have more exit work to do. */
goto again;
}
local_paca->irq_happened = 0;
@ -212,3 +216,168 @@ again:
return ret;
}
#ifdef CONFIG_PPC_BOOK3S /* BOOK3E not yet using this */
notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr)
{
#ifdef CONFIG_PPC_BOOK3E
struct thread_struct *ts = &current->thread;
#endif
unsigned long *ti_flagsp = &current_thread_info()->flags;
unsigned long ti_flags;
unsigned long flags;
unsigned long ret = 0;
if (IS_ENABLED(CONFIG_PPC_BOOK3S))
BUG_ON(!(regs->msr & MSR_RI));
BUG_ON(!(regs->msr & MSR_PR));
BUG_ON(!FULL_REGS(regs));
BUG_ON(regs->softe != IRQS_ENABLED);
local_irq_save(flags);
again:
ti_flags = READ_ONCE(*ti_flagsp);
while (unlikely(ti_flags & (_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM))) {
local_irq_enable(); /* returning to user: may enable */
if (ti_flags & _TIF_NEED_RESCHED) {
schedule();
} else {
if (ti_flags & _TIF_SIGPENDING)
ret |= _TIF_RESTOREALL;
do_notify_resume(regs, ti_flags);
}
local_irq_disable();
ti_flags = READ_ONCE(*ti_flagsp);
}
if (IS_ENABLED(CONFIG_PPC_BOOK3S) && IS_ENABLED(CONFIG_PPC_FPU)) {
if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
unlikely((ti_flags & _TIF_RESTORE_TM))) {
restore_tm_state(regs);
} else {
unsigned long mathflags = MSR_FP;
if (cpu_has_feature(CPU_FTR_VSX))
mathflags |= MSR_VEC | MSR_VSX;
else if (cpu_has_feature(CPU_FTR_ALTIVEC))
mathflags |= MSR_VEC;
if ((regs->msr & mathflags) != mathflags)
restore_math(regs);
}
}
trace_hardirqs_on();
__hard_EE_RI_disable();
if (unlikely(lazy_irq_pending())) {
__hard_RI_enable();
trace_hardirqs_off();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
local_irq_enable();
local_irq_disable();
/* Took an interrupt, may have more exit work to do. */
goto again;
}
local_paca->irq_happened = 0;
irq_soft_mask_set(IRQS_ENABLED);
#ifdef CONFIG_PPC_BOOK3E
if (unlikely(ts->debug.dbcr0 & DBCR0_IDM)) {
/*
* Check to see if the dbcr0 register is set up to debug.
* Use the internal debug mode bit to do this.
*/
mtmsr(mfmsr() & ~MSR_DE);
mtspr(SPRN_DBCR0, ts->debug.dbcr0);
mtspr(SPRN_DBSR, -1);
}
#endif
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
local_paca->tm_scratch = regs->msr;
#endif
kuap_check_amr();
account_cpu_user_exit();
return ret;
}
void unrecoverable_exception(struct pt_regs *regs);
void preempt_schedule_irq(void);
notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsigned long msr)
{
unsigned long *ti_flagsp = &current_thread_info()->flags;
unsigned long flags;
unsigned long ret = 0;
if (IS_ENABLED(CONFIG_PPC_BOOK3S) && unlikely(!(regs->msr & MSR_RI)))
unrecoverable_exception(regs);
BUG_ON(regs->msr & MSR_PR);
BUG_ON(!FULL_REGS(regs));
if (unlikely(*ti_flagsp & _TIF_EMULATE_STACK_STORE)) {
clear_bits(_TIF_EMULATE_STACK_STORE, ti_flagsp);
ret = 1;
}
local_irq_save(flags);
if (regs->softe == IRQS_ENABLED) {
/* Returning to a kernel context with local irqs enabled. */
WARN_ON_ONCE(!(regs->msr & MSR_EE));
again:
if (IS_ENABLED(CONFIG_PREEMPT)) {
/* Return to preemptible kernel context */
if (unlikely(*ti_flagsp & _TIF_NEED_RESCHED)) {
if (preempt_count() == 0)
preempt_schedule_irq();
}
}
trace_hardirqs_on();
__hard_EE_RI_disable();
if (unlikely(lazy_irq_pending())) {
__hard_RI_enable();
irq_soft_mask_set(IRQS_ALL_DISABLED);
trace_hardirqs_off();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
/*
* Can't local_irq_restore to replay if we were in
* interrupt context. Must replay directly.
*/
if (irqs_disabled_flags(flags)) {
replay_soft_interrupts();
} else {
local_irq_restore(flags);
local_irq_save(flags);
}
/* Took an interrupt, may have more exit work to do. */
goto again;
}
local_paca->irq_happened = 0;
irq_soft_mask_set(IRQS_ENABLED);
} else {
/* Returning to a kernel context with local irqs disabled. */
__hard_EE_RI_disable();
if (regs->msr & MSR_EE)
local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS;
}
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
local_paca->tm_scratch = regs->msr;
#endif
/*
* We don't need to restore AMR on the way back to userspace for KUAP.
* The value of AMR only matters while we're in the kernel.
*/
kuap_restore_amr(regs);
return ret;
}
#endif

2
arch/powerpc/kernel/vector.S
View File

@ -134,7 +134,7 @@ _GLOBAL(load_up_vsx)
/* enable use of VSX after return */
oris r12,r12,MSR_VSX@h
std r12,_MSR(r1)
b fast_exception_return
b fast_interrupt_return
#endif /* CONFIG_VSX */