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Diffstat (limited to 'arch/powerpc/include/asm/hw_irq.h')
-rw-r--r--arch/powerpc/include/asm/hw_irq.h13
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 19bcef666cf6..21cc571ea9c2 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -18,8 +18,17 @@
* PACA flags in paca->irq_happened.
*
* This bits are set when interrupts occur while soft-disabled
- * and allow a proper replay. Additionally, PACA_IRQ_HARD_DIS
- * is set whenever we manually hard disable.
+ * and allow a proper replay.
+ *
+ * The PACA_IRQ_HARD_DIS is set whenever we hard disable. It is almost
+ * always in synch with the MSR[EE] state, except:
+ * - A window in interrupt entry, where hardware disables MSR[EE] and that
+ * must be "reconciled" with the soft mask state.
+ * - NMI interrupts that hit in awkward places, until they fix the state.
+ * - When local irqs are being enabled and state is being fixed up.
+ * - When returning from an interrupt there are some windows where this
+ * can become out of synch, but gets fixed before the RFI or before
+ * executing the next user instruction (see arch/powerpc/kernel/interrupt.c).
*/
#define PACA_IRQ_HARD_DIS 0x01
#define PACA_IRQ_DBELL 0x02