#ifdef CONFIG_PPC64
-#ifndef CONFIG_SPARSE_IRQ
-EXPORT_SYMBOL(irq_desc);
-#endif
-
int distribute_irqs = 1;
-static inline notrace unsigned long get_hard_enabled(void)
+static inline notrace unsigned long get_irq_happened(void)
{
- unsigned long enabled;
+ unsigned long happened;
__asm__ __volatile__("lbz %0,%1(13)"
- : "=r" (enabled) : "i" (offsetof(struct paca_struct, hard_enabled)));
+ : "=r" (happened) : "i" (offsetof(struct paca_struct, irq_happened)));
- return enabled;
+ return happened;
}
static inline notrace void set_soft_enabled(unsigned long enable)
: : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));
}
-static inline notrace void decrementer_check_overflow(void)
+static inline notrace int decrementer_check_overflow(void)
{
- u64 now = get_tb_or_rtc();
- u64 *next_tb;
-
- preempt_disable();
- next_tb = &__get_cpu_var(decrementers_next_tb);
-
+ u64 now = get_tb_or_rtc();
+ u64 *next_tb = &__get_cpu_var(decrementers_next_tb);
+
if (now >= *next_tb)
set_dec(1);
- preempt_enable();
+ return now >= *next_tb;
}
-notrace void arch_local_irq_restore(unsigned long en)
+/* This is called whenever we are re-enabling interrupts
+ * and returns either 0 (nothing to do) or 500/900 if there's
+ * either an EE or a DEC to generate.
+ *
+ * This is called in two contexts: From arch_local_irq_restore()
+ * before soft-enabling interrupts, and from the exception exit
+ * path when returning from an interrupt from a soft-disabled to
+ * a soft enabled context. In both case we have interrupts hard
+ * disabled.
+ *
+ * We take care of only clearing the bits we handled in the
+ * PACA irq_happened field since we can only re-emit one at a
+ * time and we don't want to "lose" one.
+ */
+notrace unsigned int __check_irq_replay(void)
{
/*
- * get_paca()->soft_enabled = en;
- * Is it ever valid to use local_irq_restore(0) when soft_enabled is 1?
- * That was allowed before, and in such a case we do need to take care
- * that gcc will set soft_enabled directly via r13, not choose to use
- * an intermediate register, lest we're preempted to a different cpu.
+ * We use local_paca rather than get_paca() to avoid all
+ * the debug_smp_processor_id() business in this low level
+ * function
*/
- set_soft_enabled(en);
- if (!en)
- return;
+ unsigned char happened = local_paca->irq_happened;
-#ifdef CONFIG_PPC_STD_MMU_64
- if (firmware_has_feature(FW_FEATURE_ISERIES)) {
- /*
- * Do we need to disable preemption here? Not really: in the
- * unlikely event that we're preempted to a different cpu in
- * between getting r13, loading its lppaca_ptr, and loading
- * its any_int, we might call iseries_handle_interrupts without
- * an interrupt pending on the new cpu, but that's no disaster,
- * is it? And the business of preempting us off the old cpu
- * would itself involve a local_irq_restore which handles the
- * interrupt to that cpu.
- *
- * But use "local_paca->lppaca_ptr" instead of "get_lppaca()"
- * to avoid any preemption checking added into get_paca().
- */
- if (local_paca->lppaca_ptr->int_dword.any_int)
- iseries_handle_interrupts();
+ /* Clear bit 0 which we wouldn't clear otherwise */
+ local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS;
+
+ /*
+ * 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);
}
-#endif /* CONFIG_PPC_STD_MMU_64 */
/*
- * if (get_paca()->hard_enabled) return;
- * But again we need to take care that gcc gets hard_enabled directly
- * via r13, not choose to use an intermediate register, lest we're
- * preempted to a different cpu in between the two instructions.
+ * We may have missed a decrementer interrupt. We check the
+ * decrementer itself rather than the paca irq_happened field
+ * in case we also had a rollover while hard disabled
+ */
+ local_paca->irq_happened &= ~PACA_IRQ_DEC;
+ if (decrementer_check_overflow())
+ return 0x900;
+
+ /* Finally check if an external interrupt happened */
+ local_paca->irq_happened &= ~PACA_IRQ_EE;
+ if (happened & PACA_IRQ_EE)
+ return 0x500;
+
+#ifdef CONFIG_PPC_BOOK3E
+ /* Finally check if an EPR external interrupt happened
+ * this bit is typically set if we need to handle another
+ * "edge" interrupt from within the MPIC "EPR" handler
*/
- if (get_hard_enabled())
+ local_paca->irq_happened &= ~PACA_IRQ_EE_EDGE;
+ if (happened & PACA_IRQ_EE_EDGE)
+ return 0x500;
+
+ local_paca->irq_happened &= ~PACA_IRQ_DBELL;
+ if (happened & PACA_IRQ_DBELL)
+ return 0x280;
+#endif /* CONFIG_PPC_BOOK3E */
+
+ /* There should be nothing left ! */
+ BUG_ON(local_paca->irq_happened != 0);
+
+ return 0;
+}
+
+notrace void arch_local_irq_restore(unsigned long en)
+{
+ unsigned char irq_happened;
+ unsigned int replay;
+
+ /* Write the new soft-enabled value */
+ set_soft_enabled(en);
+ if (!en)
+ return;
+ /*
+ * From this point onward, we can take interrupts, preempt,
+ * etc... unless we got hard-disabled. We check if an event
+ * happened. If none happened, we know we can just return.
+ *
+ * We may have preempted before the check below, in which case
+ * we are checking the "new" CPU instead of the old one. This
+ * is only a problem if an event happened on the "old" CPU.
+ *
+ * External interrupt events will have caused interrupts to
+ * be hard-disabled, so there is no problem, we
+ * cannot have preempted.
+ */
+ irq_happened = get_irq_happened();
+ if (!irq_happened)
return;
/*
- * Need to hard-enable interrupts here. Since currently disabled,
- * no need to take further asm precautions against preemption; but
- * use local_paca instead of get_paca() to avoid preemption checking.
+ * We need to hard disable to get a trusted value from
+ * __check_irq_replay(). We also need to soft-disable
+ * again to avoid warnings in there due to the use of
+ * per-cpu variables.
+ *
+ * We know that if the value in irq_happened is exactly 0x01
+ * then we are already hard disabled (there are other less
+ * common cases that we'll ignore for now), so we skip the
+ * (expensive) mtmsrd.
*/
- local_paca->hard_enabled = en;
+ if (unlikely(irq_happened != PACA_IRQ_HARD_DIS))
+ __hard_irq_disable();
+ set_soft_enabled(0);
/*
- * Trigger the decrementer if we have a pending event. Some processors
- * only trigger on edge transitions of the sign bit. We might also
- * have disabled interrupts long enough that the decrementer wrapped
- * to positive.
+ * Check if anything needs to be re-emitted. We haven't
+ * soft-enabled yet to avoid warnings in decrementer_check_overflow
+ * accessing per-cpu variables
*/
- decrementer_check_overflow();
+ replay = __check_irq_replay();
+
+ /* We can soft-enable now */
+ set_soft_enabled(1);
/*
- * Force the delivery of pending soft-disabled interrupts on PS3.
- * Any HV call will have this side effect.
+ * And replay if we have to. This will return with interrupts
+ * hard-enabled.
*/
- if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
- u64 tmp, tmp2;
- lv1_get_version_info(&tmp, &tmp2);
+ if (replay) {
+ __replay_interrupt(replay);
+ return;
}
+ /* Finally, let's ensure we are hard enabled */
__hard_irq_enable();
}
EXPORT_SYMBOL(arch_local_irq_restore);
+
+/*
+ * This is specifically called by assembly code to re-enable interrupts
+ * if they are currently disabled. This is typically called before
+ * schedule() or do_signal() when returning to userspace. We do it
+ * in C to avoid the burden of dealing with lockdep etc...
+ */
+void restore_interrupts(void)
+{
+ if (irqs_disabled())
+ local_irq_enable();
+}
+
#endif /* CONFIG_PPC64 */
int arch_show_interrupts(struct seq_file *p, int prec)
check_stack_overflow();
+ /*
+ * Query the platform PIC for the interrupt & ack it.
+ *
+ * This will typically lower the interrupt line to the CPU
+ */
irq = ppc_md.get_irq();
- if (irq != NO_IRQ && irq != NO_IRQ_IGNORE)
+ /* We can hard enable interrupts now */
+ may_hard_irq_enable();
+
+ /* And finally process it */
+ if (irq != NO_IRQ)
handle_one_irq(irq);
- else if (irq != NO_IRQ_IGNORE)
+ else
__get_cpu_var(irq_stat).spurious_irqs++;
irq_exit();
set_irq_regs(old_regs);
-#ifdef CONFIG_PPC_ISERIES
- if (firmware_has_feature(FW_FEATURE_ISERIES) &&
- get_lppaca()->int_dword.fields.decr_int) {
- get_lppaca()->int_dword.fields.decr_int = 0;
- /* Signal a fake decrementer interrupt */
- timer_interrupt(regs);
- }
-#endif
-
trace_irq_exit(regs);
}
projects / karo-tx-linux.git / blobdiff