[PATCH v3 03/11] powerpc/64s: avoid reloading (H)SRR registers if they are still valid
Nicholas Piggin
npiggin at gmail.com
Thu Jun 10 23:09:13 AEST 2021
When an interrupt is taken, the SRR registers are set to return to where
it left off. Unless they are modified in the meantime, or the return
address or MSR are modified, there is no need to reload these registers
when returning from interrupt.
Introduce per-CPU flags that track the validity of SRR and HSRR
registers. These are cleared when returning from interrupt, when
using the registers for something else (e.g., OPAL calls), when
adjusting the return address or MSR of a context, and when context
switching (which changes the return address and MSR).
This improves the performance of interrupt returns.
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
arch/powerpc/Kconfig.debug | 5 ++
arch/powerpc/include/asm/hw_irq.h | 10 ++-
arch/powerpc/include/asm/interrupt.h | 12 +++
arch/powerpc/include/asm/paca.h | 4 +
arch/powerpc/include/asm/ptrace.h | 74 ++++++++++++-----
arch/powerpc/kernel/asm-offsets.c | 4 +
arch/powerpc/kernel/entry_64.S | 92 ++++++++++++++++++++--
arch/powerpc/kernel/exceptions-64s.S | 27 +++++++
arch/powerpc/kernel/fpu.S | 2 +
arch/powerpc/kernel/kgdb.c | 2 +-
arch/powerpc/kernel/kprobes-ftrace.c | 2 +-
arch/powerpc/kernel/kprobes.c | 10 +--
arch/powerpc/kernel/process.c | 26 +++---
arch/powerpc/kernel/prom_init.c | 3 +
arch/powerpc/kernel/rtas.c | 14 +++-
arch/powerpc/kernel/signal.c | 2 +-
arch/powerpc/kernel/signal_64.c | 9 +++
arch/powerpc/kernel/syscalls.c | 3 +-
arch/powerpc/kernel/traps.c | 18 ++---
arch/powerpc/kernel/vector.S | 4 +
arch/powerpc/kvm/book3s_hv.c | 3 +
arch/powerpc/kvm/book3s_pr.c | 2 +
arch/powerpc/lib/sstep.c | 4 +-
arch/powerpc/math-emu/math.c | 2 +-
arch/powerpc/platforms/powernv/opal-call.c | 4 +
arch/powerpc/platforms/pseries/hvCall.S | 29 +++++++
arch/powerpc/sysdev/fsl_pci.c | 2 +-
27 files changed, 306 insertions(+), 63 deletions(-)
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 6342f9da4545..205cd77f321f 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -84,6 +84,11 @@ config MSI_BITMAP_SELFTEST
config PPC_IRQ_SOFT_MASK_DEBUG
bool "Include extra checks for powerpc irq soft masking"
+ depends on PPC64
+
+config PPC_RFI_SRR_DEBUG
+ bool "Include extra checks for RFI SRR register validity"
+ depends on PPC_BOOK3S_64
config XMON
bool "Include xmon kernel debugger"
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 56a98936a6a9..19bcef666cf6 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -389,7 +389,15 @@ static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
return !(regs->msr & MSR_EE);
}
-static inline void may_hard_irq_enable(void) { }
+static inline bool may_hard_irq_enable(void)
+{
+ return false;
+}
+
+static inline void do_hard_irq_enable(void)
+{
+ BUILD_BUG();
+}
static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
{
diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 59f704408d65..6e9d18838d56 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -73,6 +73,18 @@
#include <asm/kprobes.h>
#include <asm/runlatch.h>
+#ifdef CONFIG_PPC_BOOK3S_64
+static inline void srr_regs_clobbered(void)
+{
+ local_paca->srr_valid = 0;
+ local_paca->hsrr_valid = 0;
+}
+#else
+static inline void srr_regs_clobbered(void)
+{
+}
+#endif
+
static inline void nap_adjust_return(struct pt_regs *regs)
{
#ifdef CONFIG_PPC_970_NAP
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index ec18ac818e3a..dfc984b0e640 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -169,6 +169,10 @@ struct paca_struct {
u64 saved_msr; /* MSR saved here by enter_rtas */
#ifdef CONFIG_PPC_BOOK3E
u16 trap_save; /* Used when bad stack is encountered */
+#endif
+#ifdef CONFIG_PPC_BOOK3S_64
+ u8 hsrr_valid; /* HSRRs set for HRFID */
+ u8 srr_valid; /* SRRs set for RFID */
#endif
u8 irq_soft_mask; /* mask for irq soft masking */
u8 irq_happened; /* irq happened while soft-disabled */
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 9c9ab2746168..516117bba4e6 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -121,27 +121,7 @@ struct pt_regs
#endif /* __powerpc64__ */
#ifndef __ASSEMBLY__
-
-static inline unsigned long instruction_pointer(struct pt_regs *regs)
-{
- return regs->nip;
-}
-
-static inline void instruction_pointer_set(struct pt_regs *regs,
- unsigned long val)
-{
- regs->nip = val;
-}
-
-static inline unsigned long user_stack_pointer(struct pt_regs *regs)
-{
- return regs->gpr[1];
-}
-
-static inline unsigned long frame_pointer(struct pt_regs *regs)
-{
- return 0;
-}
+#include <asm/paca.h>
#ifdef CONFIG_SMP
extern unsigned long profile_pc(struct pt_regs *regs);
@@ -171,6 +151,58 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
regs->gpr[3] = rc;
}
+static inline void regs_set_return_ip(struct pt_regs *regs, unsigned long ip)
+{
+ regs->nip = ip;
+#ifdef CONFIG_PPC_BOOK3S_64
+ local_paca->hsrr_valid = 0;
+ local_paca->srr_valid = 0;
+#endif
+}
+
+static inline void regs_set_return_msr(struct pt_regs *regs, unsigned long msr)
+{
+ regs->msr = msr;
+#ifdef CONFIG_PPC_BOOK3S_64
+ local_paca->hsrr_valid = 0;
+ local_paca->srr_valid = 0;
+#endif
+}
+
+static inline void return_ip_or_msr_changed(void)
+{
+#ifdef CONFIG_PPC_BOOK3S_64
+ local_paca->hsrr_valid = 0;
+ local_paca->srr_valid = 0;
+#endif
+}
+
+static inline void regs_add_return_ip(struct pt_regs *regs, long offset)
+{
+ regs_set_return_ip(regs, regs->nip + offset);
+}
+
+static inline unsigned long instruction_pointer(struct pt_regs *regs)
+{
+ return regs->nip;
+}
+
+static inline void instruction_pointer_set(struct pt_regs *regs,
+ unsigned long val)
+{
+ regs_set_return_ip(regs, val);
+}
+
+static inline unsigned long user_stack_pointer(struct pt_regs *regs)
+{
+ return regs->gpr[1];
+}
+
+static inline unsigned long frame_pointer(struct pt_regs *regs)
+{
+ return 0;
+}
+
#ifdef __powerpc64__
#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
#else
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 28af4efb4587..1c2b869d9d52 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -209,6 +209,10 @@ int main(void)
OFFSET(PACATOC, paca_struct, kernel_toc);
OFFSET(PACAKBASE, paca_struct, kernelbase);
OFFSET(PACAKMSR, paca_struct, kernel_msr);
+#ifdef CONFIG_PPC_BOOK3S
+ OFFSET(PACAHSRR_VALID, paca_struct, hsrr_valid);
+ OFFSET(PACASRR_VALID, paca_struct, srr_valid);
+#endif
OFFSET(PACAIRQSOFTMASK, paca_struct, irq_soft_mask);
OFFSET(PACAIRQHAPPENED, paca_struct, irq_happened);
OFFSET(PACA_FTRACE_ENABLED, paca_struct, ftrace_enabled);
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 03a45a88b4b8..9a1d5e5599d3 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -64,6 +64,30 @@ exception_marker:
.section ".text"
.align 7
+.macro DEBUG_SRR_VALID srr
+#ifdef CONFIG_PPC_RFI_SRR_DEBUG
+ .ifc \srr,srr
+ mfspr r11,SPRN_SRR0
+ ld r12,_NIP(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ mfspr r11,SPRN_SRR1
+ ld r12,_MSR(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ .else
+ mfspr r11,SPRN_HSRR0
+ ld r12,_NIP(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ mfspr r11,SPRN_HSRR1
+ ld r12,_MSR(r1)
+100: tdne r11,r12
+ EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE)
+ .endif
+#endif
+.endm
+
#ifdef CONFIG_PPC_BOOK3S
.macro system_call_vectored name trapnr
.globl system_call_vectored_\name
@@ -286,6 +310,11 @@ END_BTB_FLUSH_SECTION
ld r11,exception_marker at toc(r2)
std r11,-16(r10) /* "regshere" marker */
+#ifdef CONFIG_PPC_BOOK3S
+ li r11,1
+ stb r11,PACASRR_VALID(r13)
+#endif
+
/*
* We always enter kernel from userspace with irq soft-mask enabled and
* nothing pending. system_call_exception() will call
@@ -306,18 +335,27 @@ END_BTB_FLUSH_SECTION
bl syscall_exit_prepare
ld r2,_CCR(r1)
+ ld r6,_LINK(r1)
+ mtlr r6
+
+#ifdef CONFIG_PPC_BOOK3S
+ lbz r4,PACASRR_VALID(r13)
+ cmpdi r4,0
+ bne 1f
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+#endif
ld r4,_NIP(r1)
ld r5,_MSR(r1)
- ld r6,_LINK(r1)
+ mtspr SPRN_SRR0,r4
+ mtspr SPRN_SRR1,r5
+1:
+ DEBUG_SRR_VALID srr
BEGIN_FTR_SECTION
stdcx. r0,0,r1 /* to clear the reservation */
END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
- mtspr SPRN_SRR0,r4
- mtspr SPRN_SRR1,r5
- mtlr r6
-
cmpdi r3,0
bne .Lsyscall_restore_regs
/* Zero volatile regs that may contain sensitive kernel data */
@@ -673,19 +711,40 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\())
kuap_user_restore r3, r4
#endif
.Lfast_user_interrupt_return_\srr\():
- 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)
+
+#ifdef CONFIG_PPC_BOOK3S
+ .ifc \srr,srr
+ lbz r4,PACASRR_VALID(r13)
+ .else
+ lbz r4,PACAHSRR_VALID(r13)
+ .endif
+ cmpdi r4,0
+ li r4,0
+ bne 1f
+#endif
+ ld r11,_NIP(r1)
+ ld r12,_MSR(r1)
.ifc \srr,srr
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACASRR_VALID(r13)
+#endif
.else
mtspr SPRN_HSRR0,r11
mtspr SPRN_HSRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACAHSRR_VALID(r13)
+#endif
.endif
+ DEBUG_SRR_VALID \srr
BEGIN_FTR_SECTION
stdcx. r0,0,r1 /* to clear the reservation */
@@ -730,15 +789,34 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
.Lfast_kernel_interrupt_return_\srr\():
cmpdi cr1,r3,0
+#ifdef CONFIG_PPC_BOOK3S
+ .ifc \srr,srr
+ lbz r4,PACASRR_VALID(r13)
+ .else
+ lbz r4,PACAHSRR_VALID(r13)
+ .endif
+ cmpdi r4,0
+ li r4,0
+ bne 1f
+#endif
ld r11,_NIP(r1)
ld r12,_MSR(r1)
.ifc \srr,srr
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACASRR_VALID(r13)
+#endif
.else
mtspr SPRN_HSRR0,r11
mtspr SPRN_HSRR1,r12
+1:
+#ifdef CONFIG_PPC_BOOK3S
+ stb r4,PACAHSRR_VALID(r13)
+#endif
.endif
+ DEBUG_SRR_VALID \srr
BEGIN_FTR_SECTION
stdcx. r0,0,r1 /* to clear the reservation */
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 3a63feedae0b..5c18a2a3058d 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -567,6 +567,20 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
std r0,GPR0(r1) /* save r0 in stackframe */
std r10,GPR1(r1) /* save r1 in stackframe */
+ /* Mark our [H]SRRs valid for return */
+ li r10,1
+ .if IHSRR_IF_HVMODE
+ BEGIN_FTR_SECTION
+ stb r10,PACAHSRR_VALID(r13)
+ FTR_SECTION_ELSE
+ stb r10,PACASRR_VALID(r13)
+ ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
+ .elseif IHSRR
+ stb r10,PACAHSRR_VALID(r13)
+ .else
+ stb r10,PACASRR_VALID(r13)
+ .endif
+
.if ISET_RI
li r10,MSR_RI
mtmsrd r10,1 /* Set MSR_RI */
@@ -666,10 +680,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
.macro EXCEPTION_RESTORE_REGS hsrr=0
/* Move original SRR0 and SRR1 into the respective regs */
ld r9,_MSR(r1)
+ li r10,0
.if \hsrr
mtspr SPRN_HSRR1,r9
+ stb r10,PACAHSRR_VALID(r13)
.else
mtspr SPRN_SRR1,r9
+ stb r10,PACASRR_VALID(r13)
.endif
ld r9,_NIP(r1)
.if \hsrr
@@ -1825,6 +1842,8 @@ EXC_COMMON_BEGIN(hdecrementer_common)
*
* Be careful to avoid touching the kernel stack.
*/
+ li r10,0
+ stb r10,PACAHSRR_VALID(r13)
ld r10,PACA_EXGEN+EX_CTR(r13)
mtctr r10
mtcrf 0x80,r9
@@ -2660,6 +2679,8 @@ BEGIN_FTR_SECTION
ld r10,PACA_EXGEN+EX_CFAR(r13)
mtspr SPRN_CFAR,r10
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
+ li r10,0
+ stb r10,PACAHSRR_VALID(r13)
ld r10,PACA_EXGEN+EX_R10(r13)
ld r11,PACA_EXGEN+EX_R11(r13)
ld r12,PACA_EXGEN+EX_R12(r13)
@@ -2828,6 +2849,12 @@ masked_interrupt:
ori r11,r11,PACA_IRQ_HARD_DIS
stb r11,PACAIRQHAPPENED(r13)
2: /* done */
+ li r10,0
+ .if \hsrr
+ stb r10,PACAHSRR_VALID(r13)
+ .else
+ stb r10,PACASRR_VALID(r13)
+ .endif
ld r10,PACA_EXGEN+EX_CTR(r13)
mtctr r10
mtcrf 0x80,r9
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index 2c57ece6671c..44526c157bff 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -103,6 +103,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
ori r12,r12,MSR_FP
or r12,r12,r4
std r12,_MSR(r1)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
#endif
li r4,1
stb r4,THREAD_LOAD_FP(r5)
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index 7dd2ad3603ad..26163497d69e 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -147,7 +147,7 @@ static int kgdb_handle_breakpoint(struct pt_regs *regs)
return 0;
if (*(u32 *)regs->nip == BREAK_INSTR)
- regs->nip += BREAK_INSTR_SIZE;
+ regs_add_return_ip(regs, BREAK_INSTR_SIZE);
return 1;
}
diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerpc/kernel/kprobes-ftrace.c
index 660138f6c4b2..a4965a32628a 100644
--- a/arch/powerpc/kernel/kprobes-ftrace.c
+++ b/arch/powerpc/kernel/kprobes-ftrace.c
@@ -48,7 +48,7 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip,
* Emulate singlestep (and also recover regs->nip)
* as if there is a nop
*/
- regs->nip += MCOUNT_INSN_SIZE;
+ regs_add_return_ip(regs, MCOUNT_INSN_SIZE);
if (unlikely(p->post_handler)) {
kcb->kprobe_status = KPROBE_HIT_SSDONE;
p->post_handler(p, regs, 0);
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 01ab2163659e..8165ed71ab51 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -178,7 +178,7 @@ static nokprobe_inline void prepare_singlestep(struct kprobe *p, struct pt_regs
* variant as values in regs could play a part in
* if the trap is taken or not
*/
- regs->nip = (unsigned long)p->ainsn.insn;
+ regs_set_return_ip(regs, (unsigned long)p->ainsn.insn);
}
static nokprobe_inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
@@ -415,7 +415,7 @@ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
* we end up emulating it in kprobe_handler(), which increments the nip
* again.
*/
- regs->nip = orig_ret_address - 4;
+ regs_set_return_ip(regs, orig_ret_address - 4);
regs->link = orig_ret_address;
return 0;
@@ -450,7 +450,7 @@ int kprobe_post_handler(struct pt_regs *regs)
}
/* Adjust nip to after the single-stepped instruction */
- regs->nip = (unsigned long)cur->addr + len;
+ regs_set_return_ip(regs, (unsigned long)cur->addr + len);
regs->msr |= kcb->kprobe_saved_msr;
/*Restore back the original saved kprobes variables and continue. */
@@ -490,7 +490,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* and allow the page fault handler to continue as a
* normal page fault.
*/
- regs->nip = (unsigned long)cur->addr;
+ regs_set_return_ip(regs, (unsigned long)cur->addr);
regs->msr &= ~MSR_SINGLESTEP; /* Turn off 'trace' bits */
regs->msr |= kcb->kprobe_saved_msr;
if (kcb->kprobe_status == KPROBE_REENTER)
@@ -523,7 +523,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* zero, try to fix up.
*/
if ((entry = search_exception_tables(regs->nip)) != NULL) {
- regs->nip = extable_fixup(entry);
+ regs_set_return_ip(regs, extable_fixup(entry));
return 1;
}
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 89e34aa273e2..fea5c68daeef 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -96,7 +96,8 @@ static void check_if_tm_restore_required(struct task_struct *tsk)
if (tsk == current && tsk->thread.regs &&
MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
!test_thread_flag(TIF_RESTORE_TM)) {
- tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;
+ regs_set_return_msr(&tsk->thread.ckpt_regs,
+ tsk->thread.regs->msr);
set_thread_flag(TIF_RESTORE_TM);
}
}
@@ -161,7 +162,7 @@ static void __giveup_fpu(struct task_struct *tsk)
msr &= ~(MSR_FP|MSR_FE0|MSR_FE1);
if (cpu_has_feature(CPU_FTR_VSX))
msr &= ~MSR_VSX;
- tsk->thread.regs->msr = msr;
+ regs_set_return_msr(tsk->thread.regs, msr);
}
void giveup_fpu(struct task_struct *tsk)
@@ -244,7 +245,7 @@ static void __giveup_altivec(struct task_struct *tsk)
msr &= ~MSR_VEC;
if (cpu_has_feature(CPU_FTR_VSX))
msr &= ~MSR_VSX;
- tsk->thread.regs->msr = msr;
+ regs_set_return_msr(tsk->thread.regs, msr);
}
void giveup_altivec(struct task_struct *tsk)
@@ -559,7 +560,7 @@ void notrace restore_math(struct pt_regs *regs)
msr_check_and_clear(new_msr);
- regs->msr |= new_msr | fpexc_mode;
+ regs_set_return_msr(regs, regs->msr | new_msr | fpexc_mode);
}
}
#endif /* CONFIG_PPC_BOOK3S_64 */
@@ -1287,6 +1288,8 @@ struct task_struct *__switch_to(struct task_struct *prev,
}
#endif /* CONFIG_PPC_BOOK3S_64 */
+ return_ip_or_msr_changed();
+
return last;
}
@@ -1845,6 +1848,9 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
regs->gpr[2] = 0;
regs->msr = MSR_USER32;
}
+
+ return_ip_or_msr_changed();
+
#endif
#ifdef CONFIG_VSX
current->thread.used_vsr = 0;
@@ -1875,7 +1881,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
current->thread.tm_tfiar = 0;
current->thread.load_tm = 0;
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
-
}
EXPORT_SYMBOL(start_thread);
@@ -1923,9 +1928,10 @@ int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
if (val > PR_FP_EXC_PRECISE)
return -EINVAL;
tsk->thread.fpexc_mode = __pack_fe01(val);
- if (regs != NULL && (regs->msr & MSR_FP) != 0)
- regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
- | tsk->thread.fpexc_mode;
+ if (regs != NULL && (regs->msr & MSR_FP) != 0) {
+ regs_set_return_msr(regs, (regs->msr & ~(MSR_FE0|MSR_FE1))
+ | tsk->thread.fpexc_mode);
+ }
return 0;
}
@@ -1971,9 +1977,9 @@ int set_endian(struct task_struct *tsk, unsigned int val)
return -EINVAL;
if (val == PR_ENDIAN_BIG)
- regs->msr &= ~MSR_LE;
+ regs_set_return_msr(regs, regs->msr & ~MSR_LE);
else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
- regs->msr |= MSR_LE;
+ regs_set_return_msr(regs, regs->msr | MSR_LE);
else
return -EINVAL;
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 41ed7e33d897..f4774614e7eb 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -31,6 +31,7 @@
#include <asm/rtas.h>
#include <asm/page.h>
#include <asm/processor.h>
+#include <asm/interrupt.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/smp.h>
@@ -1762,6 +1763,8 @@ static int prom_rtas_hcall(uint64_t args)
asm volatile("sc 1\n" : "=r" (arg1) :
"r" (arg1),
"r" (arg2) :);
+ srr_regs_clobbered();
+
return arg1;
}
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 6bada744402b..99f2cce635fb 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -25,6 +25,7 @@
#include <linux/reboot.h>
#include <linux/syscalls.h>
+#include <asm/interrupt.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/hvcall.h>
@@ -46,6 +47,13 @@
/* This is here deliberately so it's only used in this file */
void enter_rtas(unsigned long);
+static inline void do_enter_rtas(unsigned long args)
+{
+ enter_rtas(args);
+
+ srr_regs_clobbered(); /* rtas uses SRRs, invalidate */
+}
+
struct rtas_t rtas = {
.lock = __ARCH_SPIN_LOCK_UNLOCKED
};
@@ -384,7 +392,7 @@ static char *__fetch_rtas_last_error(char *altbuf)
save_args = rtas.args;
rtas.args = err_args;
- enter_rtas(__pa(&rtas.args));
+ do_enter_rtas(__pa(&rtas.args));
err_args = rtas.args;
rtas.args = save_args;
@@ -430,7 +438,7 @@ va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
for (i = 0; i < nret; ++i)
args->rets[i] = 0;
- enter_rtas(__pa(args));
+ do_enter_rtas(__pa(args));
}
void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...)
@@ -1138,7 +1146,7 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
flags = lock_rtas();
rtas.args = args;
- enter_rtas(__pa(&rtas.args));
+ do_enter_rtas(__pa(&rtas.args));
args = rtas.args;
/* A -1 return code indicates that the last command couldn't
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 9ded046edb0e..3f851fa8f5f1 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -214,7 +214,7 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
regs->gpr[0] = __NR_restart_syscall;
else
regs->gpr[3] = regs->orig_gpr3;
- regs->nip -= 4;
+ regs_add_return_ip(regs, -4);
regs->result = 0;
} else {
if (trap_is_scv(regs)) {
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index dca66481d0c2..4a62faefba0f 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -720,6 +720,9 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
/* This returns like rt_sigreturn */
set_thread_flag(TIF_RESTOREALL);
+
+ return_ip_or_msr_changed();
+
return 0;
efault_out:
@@ -832,6 +835,9 @@ SYSCALL_DEFINE0(rt_sigreturn)
goto badframe;
set_thread_flag(TIF_RESTOREALL);
+
+ return_ip_or_msr_changed();
+
return 0;
badframe_block:
@@ -957,12 +963,15 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
if (err)
goto badframe;
+ return_ip_or_msr_changed();
+
return 0;
badframe_block:
user_write_access_end();
badframe:
signal_fault(current, regs, "handle_rt_signal64", frame);
+ return_ip_or_msr_changed();
return 1;
}
diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index a552c9e68d7e..bf4ae0f0e36c 100644
--- a/arch/powerpc/kernel/syscalls.c
+++ b/arch/powerpc/kernel/syscalls.c
@@ -114,7 +114,8 @@ SYSCALL_DEFINE0(switch_endian)
{
struct thread_info *ti;
- current->thread.regs->msr ^= MSR_LE;
+ regs_set_return_msr(current->thread.regs,
+ current->thread.regs->msr ^ MSR_LE);
/*
* Set TIF_RESTOREALL so that r3 isn't clobbered on return to
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index b4ab95c9e94a..e413f9908664 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1031,7 +1031,7 @@ static void p9_hmi_special_emu(struct pt_regs *regs)
#endif /* !__LITTLE_ENDIAN__ */
/* Go to next instruction */
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
}
#endif /* CONFIG_VSX */
@@ -1476,7 +1476,7 @@ static void do_program_check(struct pt_regs *regs)
if (!(regs->msr & MSR_PR) && /* not user-mode */
report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) {
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
return;
}
_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
@@ -1538,7 +1538,7 @@ static void do_program_check(struct pt_regs *regs)
if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
switch (emulate_instruction(regs)) {
case 0:
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
emulate_single_step(regs);
return;
case -EFAULT:
@@ -1593,7 +1593,7 @@ DEFINE_INTERRUPT_HANDLER(alignment_exception)
if (fixed == 1) {
/* skip over emulated instruction */
- regs->nip += inst_length(reason);
+ regs_add_return_ip(regs, inst_length(reason));
emulate_single_step(regs);
return;
}
@@ -1751,7 +1751,7 @@ DEFINE_INTERRUPT_HANDLER(facility_unavailable_exception)
pr_err("DSCR based mfspr emulation failed\n");
return;
}
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
emulate_single_step(regs);
}
return;
@@ -2044,7 +2044,7 @@ DEFINE_INTERRUPT_HANDLER(altivec_assist_exception)
PPC_WARN_EMULATED(altivec, regs);
err = emulate_altivec(regs);
if (err == 0) {
- regs->nip += 4; /* skip emulated instruction */
+ regs_add_return_ip(regs, 4); /* skip emulated instruction */
emulate_single_step(regs);
return;
}
@@ -2109,7 +2109,7 @@ DEFINE_INTERRUPT_HANDLER(SPEFloatingPointException)
err = do_spe_mathemu(regs);
if (err == 0) {
- regs->nip += 4; /* skip emulated instruction */
+ regs_add_return_ip(regs, 4); /* skip emulated instruction */
emulate_single_step(regs);
return;
}
@@ -2140,10 +2140,10 @@ DEFINE_INTERRUPT_HANDLER(SPEFloatingPointRoundException)
giveup_spe(current);
preempt_enable();
- regs->nip -= 4;
+ regs_add_return_ip(regs, -4);
err = speround_handler(regs);
if (err == 0) {
- regs->nip += 4; /* skip emulated instruction */
+ regs_add_return_ip(regs, 4); /* skip emulated instruction */
emulate_single_step(regs);
return;
}
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index 54dbefcb4cde..02f8925c7919 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -73,6 +73,8 @@ _GLOBAL(load_up_altivec)
addi r5,r4,THREAD /* Get THREAD */
oris r12,r12,MSR_VEC at h
std r12,_MSR(r1)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
#endif
li r4,1
stb r4,THREAD_LOAD_VEC(r5)
@@ -131,6 +133,8 @@ _GLOBAL(load_up_vsx)
/* enable use of VSX after return */
oris r12,r12,MSR_VSX at h
std r12,_MSR(r1)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
b fast_interrupt_return_srr
#endif /* CONFIG_VSX */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 28a80d240b76..efd95b867210 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4461,6 +4461,9 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
vcpu->arch.state = KVMPPC_VCPU_NOTREADY;
atomic_dec(&kvm->arch.vcpus_running);
+
+ srr_regs_clobbered();
+
return r;
}
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index d7733b07f489..1ed5ceee73eb 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -25,6 +25,7 @@
#include <asm/cputable.h>
#include <asm/cacheflush.h>
#include <linux/uaccess.h>
+#include <asm/interrupt.h>
#include <asm/io.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
@@ -1848,6 +1849,7 @@ static int kvmppc_vcpu_run_pr(struct kvm_vcpu *vcpu)
/* Make sure we save the guest TAR/EBB/DSCR state */
kvmppc_giveup_fac(vcpu, FSCR_TAR_LG);
+ srr_regs_clobbered();
out:
vcpu->mode = OUTSIDE_GUEST_MODE;
return ret;
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 45bda2520755..90fa3878299a 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -3203,7 +3203,7 @@ void emulate_update_regs(struct pt_regs *regs, struct instruction_op *op)
default:
WARN_ON_ONCE(1);
}
- regs->nip = next_pc;
+ regs_set_return_ip(regs, next_pc);
}
NOKPROBE_SYMBOL(emulate_update_regs);
@@ -3480,6 +3480,8 @@ int emulate_step(struct pt_regs *regs, struct ppc_inst instr)
unsigned long val;
unsigned long ea;
+ return_ip_or_msr_changed();
+
r = analyse_instr(&op, regs, instr);
if (r < 0)
return r;
diff --git a/arch/powerpc/math-emu/math.c b/arch/powerpc/math-emu/math.c
index 327165f26ca6..36761bd00f38 100644
--- a/arch/powerpc/math-emu/math.c
+++ b/arch/powerpc/math-emu/math.c
@@ -453,7 +453,7 @@ do_mathemu(struct pt_regs *regs)
break;
}
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
return 0;
illegal:
diff --git a/arch/powerpc/platforms/powernv/opal-call.c b/arch/powerpc/platforms/powernv/opal-call.c
index 01401e3da7ca..f812c74c61e5 100644
--- a/arch/powerpc/platforms/powernv/opal-call.c
+++ b/arch/powerpc/platforms/powernv/opal-call.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/percpu.h>
#include <linux/jump_label.h>
+#include <asm/interrupt.h>
#include <asm/opal-api.h>
#include <asm/trace.h>
#include <asm/asm-prototypes.h>
@@ -100,6 +101,9 @@ static int64_t opal_call(int64_t a0, int64_t a1, int64_t a2, int64_t a3,
bool mmu = (msr & (MSR_IR|MSR_DR));
int64_t ret;
+ /* OPAL call / firmware may use SRR and/or HSRR */
+ srr_regs_clobbered();
+
msr &= ~MSR_EE;
if (unlikely(!mmu))
diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S
index 8a2b8d64265b..ab9fc6506861 100644
--- a/arch/powerpc/platforms/pseries/hvCall.S
+++ b/arch/powerpc/platforms/pseries/hvCall.S
@@ -108,6 +108,10 @@ _GLOBAL_TOC(plpar_hcall_norets_notrace)
mfcr r0
stw r0,8(r1)
HVSC /* invoke the hypervisor */
+
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+
lwz r0,8(r1)
mtcrf 0xff,r0
blr /* return r3 = status */
@@ -120,6 +124,9 @@ _GLOBAL_TOC(plpar_hcall_norets)
HCALL_BRANCH(plpar_hcall_norets_trace)
HVSC /* invoke the hypervisor */
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+
lwz r0,8(r1)
mtcrf 0xff,r0
blr /* return r3 = status */
@@ -129,6 +136,10 @@ plpar_hcall_norets_trace:
HCALL_INST_PRECALL(R4)
HVSC
HCALL_INST_POSTCALL_NORETS
+
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+
lwz r0,8(r1)
mtcrf 0xff,r0
blr
@@ -159,6 +170,9 @@ _GLOBAL_TOC(plpar_hcall)
std r6, 16(r12)
std r7, 24(r12)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+
lwz r0,8(r1)
mtcrf 0xff,r0
@@ -188,6 +202,9 @@ plpar_hcall_trace:
HCALL_INST_POSTCALL(r12)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+
lwz r0,8(r1)
mtcrf 0xff,r0
@@ -223,6 +240,9 @@ _GLOBAL(plpar_hcall_raw)
std r6, 16(r12)
std r7, 24(r12)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+
lwz r0,8(r1)
mtcrf 0xff,r0
@@ -262,6 +282,9 @@ _GLOBAL_TOC(plpar_hcall9)
std r11,56(r12)
std r0, 64(r12)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+
lwz r0,8(r1)
mtcrf 0xff,r0
@@ -300,6 +323,9 @@ plpar_hcall9_trace:
HCALL_INST_POSTCALL(r12)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+
lwz r0,8(r1)
mtcrf 0xff,r0
@@ -339,6 +365,9 @@ _GLOBAL(plpar_hcall9_raw)
std r11,56(r12)
std r0, 64(r12)
+ li r4,0
+ stb r4,PACASRR_VALID(r13)
+
lwz r0,8(r1)
mtcrf 0xff,r0
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index 69af73765783..b8f76f3fd994 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -1072,7 +1072,7 @@ int fsl_pci_mcheck_exception(struct pt_regs *regs)
ret = get_kernel_nofault(inst, (void *)regs->nip);
if (!ret && mcheck_handle_load(regs, inst)) {
- regs->nip += 4;
+ regs_add_return_ip(regs, 4);
return 1;
}
}
--
2.23.0
More information about the Linuxppc-dev
mailing list