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-rw-r--r--arch/powerpc/kernel/entry_64.S895
1 files changed, 185 insertions, 710 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 6ba675b0cf7d..63f0a4414618 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -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>
@@ -69,6 +70,7 @@ BEGIN_FTR_SECTION
bne .Ltabort_syscall
END_FTR_SECTION_IFSET(CPU_FTR_TM)
#endif
+_ASM_NOKPROBE_SYMBOL(system_call_common)
mr r10,r1
ld r1,PACAKSAVE(r13)
std r10,0(r1)
@@ -76,342 +78,122 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM)
std r12,_MSR(r1)
std r0,GPR0(r1)
std r10,GPR1(r1)
+ std r2,GPR2(r1)
#ifdef CONFIG_PPC_FSL_BOOK3E
START_BTB_FLUSH_SECTION
BTB_FLUSH(r10)
END_BTB_FLUSH_SECTION
#endif
- ACCOUNT_CPU_USER_ENTRY(r13, r10, r11)
- std r2,GPR2(r1)
+ ld r2,PACATOC(r13)
+ mfcr r12
+ li r11,0
+ /* Can we avoid saving r3-r8 in common case? */
std r3,GPR3(r1)
- mfcr r2
std r4,GPR4(r1)
std r5,GPR5(r1)
std r6,GPR6(r1)
std r7,GPR7(r1)
std r8,GPR8(r1)
- li r11,0
+ /* Zero r9-r12, this should only be required when restoring all GPRs */
std r11,GPR9(r1)
std r11,GPR10(r1)
std r11,GPR11(r1)
std r11,GPR12(r1)
+ std r9,GPR13(r1)
+ SAVE_NVGPRS(r1)
std r11,_XER(r1)
std r11,_CTR(r1)
- std r9,GPR13(r1)
mflr r10
+
/*
* This clears CR0.SO (bit 28), which is the error indication on
* return from this system call.
*/
- rldimi r2,r11,28,(63-28)
- li r11,0xc01
+ rldimi r12,r11,28,(63-28)
+ li r11,0xc00
std r10,_LINK(r1)
std r11,_TRAP(r1)
+ std r12,_CCR(r1)
std r3,ORIG_GPR3(r1)
- std r2,_CCR(r1)
- ld r2,PACATOC(r13)
- addi r9,r1,STACK_FRAME_OVERHEAD
+ addi r10,r1,STACK_FRAME_OVERHEAD
ld r11,exception_marker@toc(r2)
- std r11,-16(r9) /* "regshere" marker */
-
- kuap_check_amr r10, r11
-
-#if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC_SPLPAR)
-BEGIN_FW_FTR_SECTION
- /* see if there are any DTL entries to process */
- ld r10,PACALPPACAPTR(r13) /* get ptr to VPA */
- ld r11,PACA_DTL_RIDX(r13) /* get log read index */
- addi r10,r10,LPPACA_DTLIDX
- LDX_BE r10,0,r10 /* get log write index */
- cmpd r11,r10
- beq+ 33f
- bl accumulate_stolen_time
- REST_GPR(0,r1)
- REST_4GPRS(3,r1)
- REST_2GPRS(7,r1)
- addi r9,r1,STACK_FRAME_OVERHEAD
-33:
-END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
-#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE && CONFIG_PPC_SPLPAR */
-
- /*
- * A syscall should always be called with interrupts enabled
- * so we just unconditionally hard-enable here. When some kind
- * of irq tracing is used, we additionally check that condition
- * is correct
- */
-#if defined(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG) && defined(CONFIG_BUG)
- lbz r10,PACAIRQSOFTMASK(r13)
-1: tdnei r10,IRQS_ENABLED
- EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
-#endif
-
-#ifdef CONFIG_PPC_BOOK3E
- wrteei 1
-#else
- li r11,MSR_RI
- ori r11,r11,MSR_EE
- mtmsrd r11,1
-#endif /* CONFIG_PPC_BOOK3E */
-
-system_call: /* label this so stack traces look sane */
- /* We do need to set SOFTE in the stack frame or the return
- * from interrupt will be painful
- */
- li r10,IRQS_ENABLED
- std r10,SOFTE(r1)
-
- ld r11, PACA_THREAD_INFO(r13)
- ld r10,TI_FLAGS(r11)
- andi. r11,r10,_TIF_SYSCALL_DOTRACE
- bne .Lsyscall_dotrace /* does not return */
- cmpldi 0,r0,NR_syscalls
- bge- .Lsyscall_enosys
+ std r11,-16(r10) /* "regshere" marker */
-.Lsyscall:
-/*
- * Need to vector to 32 Bit or default sys_call_table here,
- * based on caller's run-mode / personality.
- */
- ld r11,SYS_CALL_TABLE@toc(2)
- andis. r10,r10,_TIF_32BIT@h
- beq 15f
- ld r11,COMPAT_SYS_CALL_TABLE@toc(2)
- clrldi r3,r3,32
- clrldi r4,r4,32
- clrldi r5,r5,32
- clrldi r6,r6,32
- clrldi r7,r7,32
- clrldi r8,r8,32
-15:
- slwi r0,r0,3
-
- barrier_nospec_asm
/*
- * Prevent the load of the handler below (based on the user-passed
- * system call number) being speculatively executed until the test
- * against NR_syscalls and branch to .Lsyscall_enosys above has
- * committed.
+ * RECONCILE_IRQ_STATE without calling trace_hardirqs_off(), which
+ * would clobber syscall parameters. Also we always enter with IRQs
+ * enabled and nothing pending. system_call_exception() will call
+ * trace_hardirqs_off().
*/
+ li r11,IRQS_ALL_DISABLED
+ li r12,PACA_IRQ_HARD_DIS
+ stb r11,PACAIRQSOFTMASK(r13)
+ stb r12,PACAIRQHAPPENED(r13)
- ldx r12,r11,r0 /* Fetch system call handler [ptr] */
- mtctr r12
- bctrl /* Call handler */
+ /* Calling convention has r9 = orig r0, r10 = regs */
+ mr r9,r0
+ bl system_call_exception
- /* syscall_exit can exit to kernel mode, via ret_from_kernel_thread */
.Lsyscall_exit:
- std r3,RESULT(r1)
-
-#ifdef CONFIG_DEBUG_RSEQ
- /* Check whether the syscall is issued inside a restartable sequence */
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl rseq_syscall
- ld r3,RESULT(r1)
-#endif
-
- ld r12, PACA_THREAD_INFO(r13)
-
- ld r8,_MSR(r1)
-
-/*
- * This is a few instructions into the actual syscall exit path (which actually
- * starts at .Lsyscall_exit) to cater to kprobe blacklisting and to reduce the
- * number of visible symbols for profiling purposes.
- *
- * We can probe from system_call until this point as MSR_RI is set. But once it
- * is cleared below, we won't be able to take a trap.
- *
- * This is blacklisted from kprobes further below with _ASM_NOKPROBE_SYMBOL().
- */
-system_call_exit:
- /*
- * Disable interrupts so current_thread_info()->flags can't change,
- * and so that we don't get interrupted after loading SRR0/1.
- *
- * Leave MSR_RI enabled for now, because with THREAD_INFO_IN_TASK we
- * could fault on the load of the TI_FLAGS below.
- */
-#ifdef CONFIG_PPC_BOOK3E
- wrteei 0
-#else
- li r11,MSR_RI
- mtmsrd r11,1
-#endif /* CONFIG_PPC_BOOK3E */
+ addi r4,r1,STACK_FRAME_OVERHEAD
+ bl syscall_exit_prepare
- ld r9,TI_FLAGS(r12)
- li r11,-MAX_ERRNO
- andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
- bne- .Lsyscall_exit_work
+ ld r2,_CCR(r1)
+ ld r4,_NIP(r1)
+ ld r5,_MSR(r1)
+ ld r6,_LINK(r1)
- andi. r0,r8,MSR_FP
- beq 2f
-#ifdef CONFIG_ALTIVEC
- andis. r0,r8,MSR_VEC@h
- bne 3f
-#endif
-2: addi r3,r1,STACK_FRAME_OVERHEAD
- bl restore_math
- ld r8,_MSR(r1)
- ld r3,RESULT(r1)
- li r11,-MAX_ERRNO
-
-3: cmpld r3,r11
- ld r5,_CCR(r1)
- bge- .Lsyscall_error
-.Lsyscall_error_cont:
- ld r7,_NIP(r1)
BEGIN_FTR_SECTION
stdcx. r0,0,r1 /* to clear the reservation */
END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
- andi. r6,r8,MSR_PR
- ld r4,_LINK(r1)
- kuap_check_amr r10, r11
+ mtspr SPRN_SRR0,r4
+ mtspr SPRN_SRR1,r5
+ mtlr r6
-#ifdef CONFIG_PPC_BOOK3S
- /*
- * Clear MSR_RI, MSR_EE is already and remains disabled. We could do
- * this later, but testing shows that doing it here causes less slow
- * down than doing it closer to the rfid.
- */
+ cmpdi r3,0
+ bne .Lsyscall_restore_regs
+ /* Zero volatile regs that may contain sensitive kernel data */
+ li r0,0
+ li r4,0
+ li r5,0
+ li r6,0
+ li r7,0
+ li r8,0
+ li r9,0
+ li r10,0
li r11,0
- mtmsrd r11,1
-#endif
-
- beq- 1f
- ACCOUNT_CPU_USER_EXIT(r13, r11, r12)
+ li r12,0
+ mtctr r0
+ mtspr SPRN_XER,r0
+.Lsyscall_restore_regs_cont:
BEGIN_FTR_SECTION
HMT_MEDIUM_LOW
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
- std r8, PACATMSCRATCH(r13)
-#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.
*/
- ld r13,GPR13(r1) /* only restore r13 if returning to usermode */
+ mtcr r2
ld r2,GPR2(r1)
+ ld r3,GPR3(r1)
+ ld r13,GPR13(r1)
ld r1,GPR1(r1)
- mtlr r4
- mtcr r5
- mtspr SPRN_SRR0,r7
- mtspr SPRN_SRR1,r8
RFI_TO_USER
b . /* prevent speculative execution */
-1: /* exit to kernel */
- kuap_restore_amr r2
-
- ld r2,GPR2(r1)
- ld r1,GPR1(r1)
- mtlr r4
- mtcr r5
- mtspr SPRN_SRR0,r7
- mtspr SPRN_SRR1,r8
- RFI_TO_KERNEL
- b . /* prevent speculative execution */
-
-.Lsyscall_error:
- oris r5,r5,0x1000 /* Set SO bit in CR */
- neg r3,r3
- std r5,_CCR(r1)
- b .Lsyscall_error_cont
-
-/* Traced system call support */
-.Lsyscall_dotrace:
- bl save_nvgprs
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl do_syscall_trace_enter
-
- /*
- * We use the return value of do_syscall_trace_enter() as the syscall
- * number. If the syscall was rejected for any reason do_syscall_trace_enter()
- * returns an invalid syscall number and the test below against
- * NR_syscalls will fail.
- */
- mr r0,r3
-
- /* Restore argument registers just clobbered and/or possibly changed. */
- ld r3,GPR3(r1)
- ld r4,GPR4(r1)
- ld r5,GPR5(r1)
- ld r6,GPR6(r1)
- ld r7,GPR7(r1)
- ld r8,GPR8(r1)
-
- /* Repopulate r9 and r10 for the syscall path */
- addi r9,r1,STACK_FRAME_OVERHEAD
- ld r10, PACA_THREAD_INFO(r13)
- ld r10,TI_FLAGS(r10)
-
- cmpldi r0,NR_syscalls
- blt+ .Lsyscall
-
- /* Return code is already in r3 thanks to do_syscall_trace_enter() */
- b .Lsyscall_exit
-
-
-.Lsyscall_enosys:
- li r3,-ENOSYS
- b .Lsyscall_exit
-
-.Lsyscall_exit_work:
- /* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr.
- If TIF_NOERROR is set, just save r3 as it is. */
-
- andi. r0,r9,_TIF_RESTOREALL
- beq+ 0f
+.Lsyscall_restore_regs:
+ ld r3,_CTR(r1)
+ ld r4,_XER(r1)
REST_NVGPRS(r1)
- b 2f
-0: cmpld r3,r11 /* r11 is -MAX_ERRNO */
- blt+ 1f
- andi. r0,r9,_TIF_NOERROR
- bne- 1f
- ld r5,_CCR(r1)
- neg r3,r3
- oris r5,r5,0x1000 /* Set SO bit in CR */
- std r5,_CCR(r1)
-1: std r3,GPR3(r1)
-2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
- beq 4f
-
- /* Clear per-syscall TIF flags if any are set. */
-
- li r11,_TIF_PERSYSCALL_MASK
- addi r12,r12,TI_FLAGS
-3: ldarx r10,0,r12
- andc r10,r10,r11
- stdcx. r10,0,r12
- bne- 3b
- subi r12,r12,TI_FLAGS
-
-4: /* Anything else left to do? */
-BEGIN_FTR_SECTION
- lis r3,DEFAULT_PPR@highest /* Set default PPR */
- sldi r3,r3,32 /* bits 11-13 are used for ppr */
- std r3,_PPR(r1)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-
- andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP)
- beq ret_from_except_lite
-
- /* Re-enable interrupts */
-#ifdef CONFIG_PPC_BOOK3E
- wrteei 1
-#else
- li r10,MSR_RI
- ori r10,r10,MSR_EE
- mtmsrd r10,1
-#endif /* CONFIG_PPC_BOOK3E */
-
- bl save_nvgprs
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl do_syscall_trace_leave
- b ret_from_except
+ mtctr r3
+ mtspr SPRN_XER,r4
+ ld r0,GPR0(r1)
+ REST_8GPRS(4, r1)
+ ld r12,GPR12(r1)
+ b .Lsyscall_restore_regs_cont
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
.Ltabort_syscall:
@@ -439,64 +221,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
RFI_TO_USER
b . /* prevent speculative execution */
#endif
-_ASM_NOKPROBE_SYMBOL(system_call_common);
-_ASM_NOKPROBE_SYMBOL(system_call_exit);
-
-/* Save non-volatile GPRs, if not already saved. */
-_GLOBAL(save_nvgprs)
- ld r11,_TRAP(r1)
- andi. r0,r11,1
- beqlr-
- SAVE_NVGPRS(r1)
- clrrdi r0,r11,1
- std r0,_TRAP(r1)
- blr
-_ASM_NOKPROBE_SYMBOL(save_nvgprs);
-
-
-/*
- * The sigsuspend and rt_sigsuspend system calls can call do_signal
- * and thus put the process into the stopped state where we might
- * want to examine its user state with ptrace. Therefore we need
- * to save all the nonvolatile registers (r14 - r31) before calling
- * the C code. Similarly, fork, vfork and clone need the full
- * register state on the stack so that it can be copied to the child.
- */
-
-_GLOBAL(ppc_fork)
- bl save_nvgprs
- bl sys_fork
- b .Lsyscall_exit
-
-_GLOBAL(ppc_vfork)
- bl save_nvgprs
- bl sys_vfork
- b .Lsyscall_exit
-
-_GLOBAL(ppc_clone)
- bl save_nvgprs
- bl sys_clone
- b .Lsyscall_exit
-
-_GLOBAL(ppc_clone3)
- bl save_nvgprs
- bl sys_clone3
- b .Lsyscall_exit
-
-_GLOBAL(ppc32_swapcontext)
- bl save_nvgprs
- bl compat_sys_swapcontext
- b .Lsyscall_exit
-
-_GLOBAL(ppc64_swapcontext)
- bl save_nvgprs
- bl sys_swapcontext
- b .Lsyscall_exit
-
-_GLOBAL(ppc_switch_endian)
- bl save_nvgprs
- bl sys_switch_endian
- b .Lsyscall_exit
_GLOBAL(ret_from_fork)
bl schedule_tail
@@ -516,6 +240,19 @@ _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)
+ andi. r0,r11,1
+ beqlr-
+ SAVE_NVGPRS(r1)
+ clrrdi r0,r11,1
+ std r0,_TRAP(r1)
+ blr
+_ASM_NOKPROBE_SYMBOL(save_nvgprs);
+#endif
+
#ifdef CONFIG_PPC_BOOK3S_64
#define FLUSH_COUNT_CACHE \
@@ -578,7 +315,7 @@ 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.
*
@@ -730,408 +467,146 @@ 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
- 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
+#ifdef CONFIG_PPC_BOOK3S
/*
- * 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
+ * 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 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
+ bl unrecoverable_exception
+ b . /* should not get here */
+
+ .balign IFETCH_ALIGN_BYTES
+ .globl interrupt_return
+interrupt_return:
+_ASM_NOKPROBE_SYMBOL(interrupt_return)
+ ld r4,_MSR(r1)
+ andi. r0,r4,MSR_PR
+ beq .Lkernel_interrupt_return
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
+ bl interrupt_exit_user_prepare
+ cmpdi r3,0
+ bne- .Lrestore_nvgprs
- addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */
+.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
- 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 */
+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)
- /* 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
+ ld r3,_CCR(r1)
+ ld r4,_LINK(r1)
+ ld r5,_CTR(r1)
+ ld r6,_XER(r1)
+ li r0,0
- /*
- * 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
+ REST_4GPRS(7, r1)
+ REST_2GPRS(11, r1)
+ REST_GPR(13, r1)
- /*
- * 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 */
+ mtcr r3
+ mtlr r4
+ mtctr r5
+ mtspr SPRN_XER,r6
- .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
+ REST_4GPRS(2, r1)
+ REST_GPR(6, r1)
+ REST_GPR(0, r1)
+ REST_GPR(1, r1)
+ RFI_TO_USER
+ b . /* prevent speculative execution */
- /* We are enabling, were we already enabled ? Yes, just return */
- andi. r6,r6,IRQS_DISABLED
- beq cr0,.Ldo_restore
+.Lrestore_nvgprs:
+ REST_NVGPRS(r1)
+ b .Lfast_user_interrupt_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
+ .balign IFETCH_ALIGN_BYTES
+.Lkernel_interrupt_return:
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl interrupt_exit_kernel_prepare
- /*
- * 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);
+.Lfast_kernel_interrupt_return:
+ cmpdi cr1,r3,0
+ ld r11,_NIP(r1)
+ ld r12,_MSR(r1)
+ mtspr SPRN_SRR0,r11
+ mtspr SPRN_SRR1,r12
- /*
- * 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 r3,_LINK(r1)
ld r4,_CTR(r1)
- ld r0,_LINK(r1)
- mtctr r4
- mtlr r0
- ld r4,_XER(r1)
- mtspr SPRN_XER,r4
-
- 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_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
-
- 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)
- RFI_TO_USER
- b . /* prevent speculative execution */
+ ld r5,_XER(r1)
+ ld r6,_CCR(r1)
+ li r0,0
-1: mtspr SPRN_SRR1,r3
+ REST_4GPRS(7, r1)
+ REST_2GPRS(11, r1)
- ld r2,_CCR(r1)
- mtcrf 0xFF,r2
- ld r2,_NIP(r1)
- mtspr SPRN_SRR0,r2
+ 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)
-
- ld r0,GPR0(r1)
- ld r2,GPR2(r1)
- ld r3,GPR3(r1)
+ std r0,STACK_FRAME_OVERHEAD-16(r1)
- kuap_restore_amr r4
+ REST_4GPRS(2, r1)
- 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
- */
-.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);
+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.
+ */
+ 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
/*