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, 3 insertions, 14 deletions

diff --git a/arch/s390/include/asm/hw_irq.h b/arch/s390/include/asm/hw_irq.h
index 7e3d2586c1f..ee96a8b697f 100644
--- a/arch/s390/include/asm/hw_irq.h
+++ b/arch/s390/include/asm/hw_irq.h
@@ -4,19 +4,8 @@
 #include <linux/msi.h>
 #include <linux/pci.h>
 
-static inline struct msi_desc *irq_get_msi_desc(unsigned int irq)
-{
-	return __irq_get_msi_desc(irq);
-}
-
-/* Must be called with msi map lock held */
-static inline int irq_set_msi_desc(unsigned int irq, struct msi_desc *msi)
-{
-	if (!msi)
-		return -EINVAL;
-
-	msi->irq = irq;
-	return 0;
-}
+void __init init_airq_interrupts(void);
+void __init init_cio_interrupts(void);
+void __init init_ext_interrupts(void);
 
 #endif