#include <asm/ptrace.h>
#include <asm/irqflags.h>
#include <asm/ftrace.h>
+#include <asm/hw_irq.h>
/*
* System calls.
END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
#endif /* CONFIG_VIRT_CPU_ACCOUNTING && CONFIG_PPC_SPLPAR */
-#ifdef CONFIG_TRACE_IRQFLAGS
- bl .trace_hardirqs_on
- REST_GPR(0,r1)
- REST_4GPRS(3,r1)
- REST_2GPRS(7,r1)
- addi r9,r1,STACK_FRAME_OVERHEAD
- ld r12,_MSR(r1)
-#endif /* CONFIG_TRACE_IRQFLAGS */
- li r10,1
- stb r10,PACASOFTIRQEN(r13)
- stb r10,PACAHARDIRQEN(r13)
- std r10,SOFTE(r1)
-#ifdef CONFIG_PPC_ISERIES
-BEGIN_FW_FTR_SECTION
- /* Hack for handling interrupts when soft-enabling on iSeries */
- cmpdi cr1,r0,0x5555 /* syscall 0x5555 */
- andi. r10,r12,MSR_PR /* from kernel */
- crand 4*cr0+eq,4*cr1+eq,4*cr0+eq
- bne 2f
- b hardware_interrupt_entry
-2:
-END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
-#endif /* CONFIG_PPC_ISERIES */
+ /*
+ * 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_TRACE_IRQFLAGS) && defined(CONFIG_BUG)
+ lbz r10,PACASOFTIRQEN(r13)
+ xori r10,r10,1
+1: tdnei r10,0
+ EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
+#endif
- /* Hard enable interrupts */
#ifdef CONFIG_PPC_BOOK3E
wrteei 1
#else
- mfmsr r11
+ ld r11,PACAKMSR(r13)
ori r11,r11,MSR_EE
mtmsrd r11,1
#endif /* CONFIG_PPC_BOOK3E */
+ /* We do need to set SOFTE in the stack frame or the return
+ * from interrupt will be painful
+ */
+ li r10,1
+ std r10,SOFTE(r1)
+
#ifdef SHOW_SYSCALLS
bl .do_show_syscall
REST_GPR(0,r1)
andi. r10,r8,MSR_RI
beq- unrecov_restore
#endif
-
- /* Disable interrupts so current_thread_info()->flags can't change,
+ /*
+ * Disable interrupts so current_thread_info()->flags can't change,
* and so that we don't get interrupted after loading SRR0/1.
*/
#ifdef CONFIG_PPC_BOOK3E
wrteei 0
#else
- mfmsr r10
- rldicl r10,r10,48,1
- rotldi r10,r10,16
+ ld r10,PACAKMSR(r13)
mtmsrd r10,1
#endif /* CONFIG_PPC_BOOK3E */
#ifdef CONFIG_PPC_BOOK3E
wrteei 1
#else
- mfmsr r10
+ ld r10,PACAKMSR(r13)
ori r10,r10,MSR_EE
mtmsrd r10,1
#endif /* CONFIG_PPC_BOOK3E */
#ifdef CONFIG_PPC_BOOK3E
wrteei 0
#else
- mfmsr r10 /* Get current interrupt state */
- rldicl r9,r10,48,1 /* clear MSR_EE */
- rotldi r9,r9,16
- mtmsrd r9,1 /* Update machine state */
+ ld r10,PACAKMSR(r13) /* Get kernel MSR without EE */
+ mtmsrd r10,1 /* Update machine state */
#endif /* CONFIG_PPC_BOOK3E */
#ifdef CONFIG_PREEMPT
ld r4,TI_FLAGS(r9)
andi. r0,r4,_TIF_USER_WORK_MASK
bne do_work
-#endif
+#endif /* !CONFIG_PREEMPT */
+ .globl fast_exc_return_irq
+fast_exc_return_irq:
restore:
-BEGIN_FW_FTR_SECTION
+ /*
+ * This is the main kernel exit path, we first check if we
+ * have to change our interrupt state.
+ */
ld r5,SOFTE(r1)
-FW_FTR_SECTION_ELSE
- b .Liseries_check_pending_irqs
-ALT_FW_FTR_SECTION_END_IFCLR(FW_FEATURE_ISERIES)
-2:
- TRACE_AND_RESTORE_IRQ(r5);
+ lbz r6,PACASOFTIRQEN(r13)
+ cmpwi cr1,r5,0
+ cmpw cr0,r5,r6
+ beq cr0,4f
+
+ /* We do, handle disable first, which is easy */
+ bne cr1,3f;
+ li r0,0
+ stb r0,PACASOFTIRQEN(r13);
+ TRACE_DISABLE_INTS
+ b 4f
- /* extract EE bit and use it to restore paca->hard_enabled */
- ld r3,_MSR(r1)
- rldicl r4,r3,49,63 /* r0 = (r3 >> 15) & 1 */
- stb r4,PACAHARDIRQEN(r13)
+3: /*
+ * 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- restore_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
+ */
+restore_no_replay:
+ TRACE_ENABLE_INTS
+ li r0,1
+ stb r0,PACASOFTIRQEN(r13);
+
+ /*
+ * Final return path. BookE is handled in a different file
+ */
+4:
#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
+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
andi. r0,r3,MSR_RI
beq- unrecov_restore
- /*
- * 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
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
-
/*
* 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.
*/
- mfmsr r4
- andc r4,r4,r0 /* r0 contains MSR_RI here */
+ ld r4,PACAKMSR(r13) /* Get kernel MSR without EE */
+ andc r4,r4,r0 /* r0 contains MSR_RI here */
mtmsrd r4,1
/*
* r13 is our per cpu area, only restore it if we are returning to
- * userspace
+ * userspace the value stored in the stack frame may belong to
+ * another CPU.
*/
andi. r0,r3,MSR_PR
beq 1f
#endif /* CONFIG_PPC_BOOK3E */
-.Liseries_check_pending_irqs:
-#ifdef CONFIG_PPC_ISERIES
- ld r5,SOFTE(r1)
- cmpdi 0,r5,0
- beq 2b
- /* Check for pending interrupts (iSeries) */
- ld r3,PACALPPACAPTR(r13)
- ld r3,LPPACAANYINT(r3)
- cmpdi r3,0
- beq+ 2b /* skip do_IRQ if no interrupts */
-
- li r3,0
- stb r3,PACASOFTIRQEN(r13) /* ensure we are soft-disabled */
-#ifdef CONFIG_TRACE_IRQFLAGS
- bl .trace_hardirqs_off
- mfmsr r10
-#endif
- ori r10,r10,MSR_EE
- mtmsrd r10 /* hard-enable again */
- addi r3,r1,STACK_FRAME_OVERHEAD
- bl .do_IRQ
- b .ret_from_except_lite /* loop back and handle more */
-#endif
+ /*
+ * Something did happen, check if a re-emit is needed
+ * (this also clears paca->irq_happened)
+ */
+restore_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 restore_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)
+ /*
+ * 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,r3,0x900
+ bne 1f
+ addi r3,r1,STACK_FRAME_OVERHEAD;
+ bl .timer_interrupt
+ b .ret_from_except
+#ifdef CONFIG_PPC_BOOK3E
+1: cmpwi cr0,r3,0x280
+ bne 1f
+ addi r3,r1,STACK_FRAME_OVERHEAD;
+ bl .doorbell_exception
+ b .ret_from_except
+#endif /* CONFIG_PPC_BOOK3E */
+1: b .ret_from_except /* What else to do here ? */
+
do_work:
#ifdef CONFIG_PREEMPT
andi. r0,r3,MSR_PR /* Returning to user mode? */
crandc eq,cr1*4+eq,eq
bne restore
- /* Here we are preempting the current task.
- *
- * Ensure interrupts are soft-disabled. We also properly mark
- * the PACA to reflect the fact that they are hard-disabled
- * and trace the change
+ /*
+ * Here we are preempting the current task. We want to make
+ * sure we are soft-disabled first
*/
- li r0,0
- stb r0,PACASOFTIRQEN(r13)
- stb r0,PACAHARDIRQEN(r13)
- TRACE_DISABLE_INTS
-
- /* Call the scheduler with soft IRQs off */
+ SOFT_DISABLE_INTS(r3,r4)
1: bl .preempt_schedule_irq
/* Hard-disable interrupts again (and update PACA) */
#ifdef CONFIG_PPC_BOOK3E
wrteei 0
#else
- mfmsr r10
- rldicl r10,r10,48,1
- rotldi r10,r10,16
+ ld r10,PACAKMSR(r13) /* Get kernel MSR without EE */
mtmsrd r10,1
#endif /* CONFIG_PPC_BOOK3E */
- li r0,0
- stb r0,PACAHARDIRQEN(r13)
+ li r0,PACA_IRQ_HARD_DIS
+ stb r0,PACAIRQHAPPENED(r13)
/* Re-test flags and eventually loop */
clrrdi r9,r1,THREAD_SHIFT
andi. r0,r4,_TIF_NEED_RESCHED
beq 1f
- li r5,1
- TRACE_AND_RESTORE_IRQ(r5);
+ bl .restore_interrupts
bl .schedule
b .ret_from_except_lite
1: bl .save_nvgprs
- li r5,1
- TRACE_AND_RESTORE_IRQ(r5);
+ bl .restore_interrupts
addi r3,r1,STACK_FRAME_OVERHEAD
bl .do_notify_resume
b .ret_from_except
projects / ~andy / linux / blobdiff