mflr r9
lwz r11,0(r9) /* virtual address of handler */
lwz r9,4(r9) /* where to go when done */
+#ifdef CONFIG_TRACE_IRQFLAGS
+ lis r12,reenable_mmu@h
+ ori r12,r12,reenable_mmu@l
+ mtspr SPRN_SRR0,r12
+ mtspr SPRN_SRR1,r10
+ SYNC
+ RFI
+reenable_mmu: /* re-enable mmu so we can */
+ mfmsr r10
+ lwz r12,_MSR(r1)
+ xor r10,r10,r12
+ andi. r10,r10,MSR_EE /* Did EE change? */
+ beq 1f
+
+ /* Save handler and return address into the 2 unused words
+ * of the STACK_FRAME_OVERHEAD (sneak sneak sneak). Everything
+ * else can be recovered from the pt_regs except r3 which for
+ * normal interrupts has been set to pt_regs and for syscalls
+ * is an argument, so we temporarily use ORIG_GPR3 to save it
+ */
+ stw r9,8(r1)
+ stw r11,12(r1)
+ stw r3,ORIG_GPR3(r1)
+ bl trace_hardirqs_off
+ lwz r0,GPR0(r1)
+ lwz r3,ORIG_GPR3(r1)
+ lwz r4,GPR4(r1)
+ lwz r5,GPR5(r1)
+ lwz r6,GPR6(r1)
+ lwz r7,GPR7(r1)
+ lwz r8,GPR8(r1)
+ lwz r9,8(r1)
+ lwz r11,12(r1)
+1: mtctr r11
+ mtlr r9
+ bctr /* jump to handler */
+#else /* CONFIG_TRACE_IRQFLAGS */
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r10
mtlr r9
SYNC
RFI /* jump to handler, enable MMU */
+#endif /* CONFIG_TRACE_IRQFLAGS */
#if defined (CONFIG_6xx) || defined(CONFIG_E500)
4: rlwinm r12,r12,0,~_TLF_NAPPING
#ifdef SHOW_SYSCALLS
bl do_show_syscall
#endif /* SHOW_SYSCALLS */
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* Return from syscalls can (and generally will) hard enable
+ * interrupts. You aren't supposed to call a syscall with
+ * interrupts disabled in the first place. However, to ensure
+ * that we get it right vs. lockdep if it happens, we force
+ * that hard enable here with appropriate tracing if we see
+ * that we have been called with interrupts off
+ */
+ mfmsr r11
+ andi. r12,r11,MSR_EE
+ bne+ 1f
+ /* We came in with interrupts disabled, we enable them now */
+ bl trace_hardirqs_on
+ mfmsr r11
+ lwz r0,GPR0(r1)
+ lwz r3,GPR3(r1)
+ lwz r4,GPR4(r1)
+ ori r11,r11,MSR_EE
+ lwz r5,GPR5(r1)
+ lwz r6,GPR6(r1)
+ lwz r7,GPR7(r1)
+ lwz r8,GPR8(r1)
+ mtmsr r11
+1:
+#endif /* CONFIG_TRACE_IRQFLAGS */
rlwinm r10,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */
lwz r11,TI_FLAGS(r10)
andi. r11,r11,_TIF_SYSCALL_T_OR_A
rlwinm r12,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */
/* disable interrupts so current_thread_info()->flags can't change */
LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */
+ /* Note: We don't bother telling lockdep about it */
SYNC
MTMSRD(r10)
lwz r9,TI_FLAGS(r12)
oris r11,r11,0x1000 /* Set SO bit in CR */
stw r11,_CCR(r1)
syscall_exit_cont:
+ lwz r8,_MSR(r1)
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* If we are going to return from the syscall with interrupts
+ * off, we trace that here. It shouldn't happen though but we
+ * want to catch the bugger if it does right ?
+ */
+ andi. r10,r8,MSR_EE
+ bne+ 1f
+ stw r3,GPR3(r1)
+ bl trace_hardirqs_off
+ lwz r3,GPR3(r1)
+1:
+#endif /* CONFIG_TRACE_IRQFLAGS */
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
/* If the process has its own DBCR0 value, load it up. The internal
debug mode bit tells us that dbcr0 should be loaded. */
mtlr r4
mtcr r5
lwz r7,_NIP(r1)
- lwz r8,_MSR(r1)
FIX_SRR1(r8, r0)
lwz r2,GPR2(r1)
lwz r1,GPR1(r1)
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP)
beq ret_from_except
- /* Re-enable interrupts */
+ /* Re-enable interrupts. There is no need to trace that with
+ * lockdep as we are supposed to have IRQs on at this point
+ */
ori r10,r10,MSR_EE
SYNC
MTMSRD(r10)
/* Hard-disable interrupts so that current_thread_info()->flags
* can't change between when we test it and when we return
* from the interrupt. */
+ /* Note: We don't bother telling lockdep about it */
LOAD_MSR_KERNEL(r10,MSR_KERNEL)
SYNC /* Some chip revs have problems here... */
MTMSRD(r10) /* disable interrupts */
beq+ restore
andi. r0,r3,MSR_EE /* interrupts off? */
beq restore /* don't schedule if so */
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* Lockdep thinks irqs are enabled, we need to call
+ * preempt_schedule_irq with IRQs off, so we inform lockdep
+ * now that we -did- turn them off already
+ */
+ bl trace_hardirqs_off
+#endif
1: bl preempt_schedule_irq
rlwinm r9,r1,0,0,(31-THREAD_SHIFT)
lwz r3,TI_FLAGS(r9)
andi. r0,r3,_TIF_NEED_RESCHED
bne- 1b
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* And now, to properly rebalance the above, we tell lockdep they
+ * are being turned back on, which will happen when we return
+ */
+ bl trace_hardirqs_on
+#endif
#else
resume_kernel:
#endif /* CONFIG_PREEMPT */
stw r6,icache_44x_need_flush@l(r4)
1:
#endif /* CONFIG_44x */
+
+ lwz r9,_MSR(r1)
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* Lockdep doesn't know about the fact that IRQs are temporarily turned
+ * off in this assembly code while peeking at TI_FLAGS() and such. However
+ * we need to inform it if the exception turned interrupts off, and we
+ * are about to trun them back on.
+ *
+ * The problem here sadly is that we don't know whether the exceptions was
+ * one that turned interrupts off or not. So we always tell lockdep about
+ * turning them on here when we go back to wherever we came from with EE
+ * on, even if that may meen some redudant calls being tracked. Maybe later
+ * we could encode what the exception did somewhere or test the exception
+ * type in the pt_regs but that sounds overkill
+ */
+ andi. r10,r9,MSR_EE
+ beq 1f
+ bl trace_hardirqs_on
+ lwz r9,_MSR(r1)
+1:
+#endif /* CONFIG_TRACE_IRQFLAGS */
+
lwz r0,GPR0(r1)
lwz r2,GPR2(r1)
REST_4GPRS(3, r1)
stwcx. r0,0,r1 /* to clear the reservation */
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
- lwz r9,_MSR(r1)
andi. r10,r9,MSR_RI /* check if this exception occurred */
beql nonrecoverable /* at a bad place (MSR:RI = 0) */
MTMSRD(r10) /* clear the RI bit */
.globl exc_exit_restart
exc_exit_restart:
- lwz r9,_MSR(r1)
lwz r12,_NIP(r1)
FIX_SRR1(r9,r10)
mtspr SPRN_SRR0,r12
beq do_user_signal
do_resched: /* r10 contains MSR_KERNEL here */
+ /* Note: We don't need to inform lockdep that we are enabling
+ * interrupts here. As far as it knows, they are already enabled
+ */
ori r10,r10,MSR_EE
SYNC
MTMSRD(r10) /* hard-enable interrupts */
bl schedule
recheck:
+ /* Note: And we don't tell it we are disabling them again
+ * neither. Those disable/enable cycles used to peek at
+ * TI_FLAGS aren't advertised.
+ */
LOAD_MSR_KERNEL(r10,MSR_KERNEL)
SYNC
MTMSRD(r10) /* disable interrupts */
git.openpandora.org / pandora-kernel.git / blobdiff