s390: convert interrupt handling to use generic hardirq

With the introduction of PCI it became apparent that s390 should
convert to generic hardirqs as too many drivers do not have the
correct dependency for GENERIC_HARDIRQS. On the architecture
level s390 does not have irq lines. It has external interrupts,
I/O interrupts and adapter interrupts. This patch hard-codes all
external interrupts as irq #1, all I/O interrupts as irq #2 and
all adapter interrupts as irq #3. The additional information from
the lowcore associated with the interrupt is stored in the
pt_regs of the interrupt frame, where the interrupt handler can
pick it up. For PCI/MSI interrupts the adapter interrupt handler
scans the relevant bit fields and calls generic_handle_irq with
the virtual irq number for the MSI interrupt.

Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 20 insertions, 15 deletions

diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h
index 87c17bfb2968..1eaa3625803c 100644
--- a/arch/s390/include/asm/irq.h
+++ b/arch/s390/include/asm/irq.h
@@ -1,17 +1,28 @@
 #ifndef _ASM_IRQ_H
 #define _ASM_IRQ_H
 
+#define EXT_INTERRUPT	1
+#define IO_INTERRUPT	2
+#define THIN_INTERRUPT	3
+
+#define NR_IRQS_BASE	4
+
+#ifdef CONFIG_PCI_NR_MSI
+# define NR_IRQS	(NR_IRQS_BASE + CONFIG_PCI_NR_MSI)
+#else
+# define NR_IRQS	NR_IRQS_BASE
+#endif
+
+/* This number is used when no interrupt has been assigned */
+#define NO_IRQ		0
+
+#ifndef __ASSEMBLY__
+
 #include <linux/hardirq.h>
 #include <linux/percpu.h>
 #include <linux/cache.h>
 #include <linux/types.h>
 
-enum interruption_main_class {
-	EXTERNAL_INTERRUPT,
-	IO_INTERRUPT,
-	NR_IRQS
-};
-
 enum interruption_class {
 	IRQEXT_CLK,
 	IRQEXT_EXC,
@@ -72,14 +83,8 @@ void service_subclass_irq_unregister(void);
 void measurement_alert_subclass_register(void);
 void measurement_alert_subclass_unregister(void);
 
-#ifdef CONFIG_LOCKDEP
-#  define disable_irq_nosync_lockdep(irq)	disable_irq_nosync(irq)
-#  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
-						disable_irq_nosync(irq)
-#  define disable_irq_lockdep(irq)		disable_irq(irq)
-#  define enable_irq_lockdep(irq)		enable_irq(irq)
-#  define enable_irq_lockdep_irqrestore(irq, flags) \
-						enable_irq(irq)
-#endif
+#define irq_canonicalize(irq)  (irq)
+
+#endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_IRQ_H */