[SPARC64]: Add support for IRQ pre-handlers.

This allows a PCI controller to shim into IRQ delivery
so that DMA queues can be drained, if necessary.

If some bus specific code needs to run before an IRQ
handler is invoked, the bus driver simply needs to setup
the function pointer in bucket->irq_info->pre_handler and
the two args bucket->irq_info->pre_handler_arg[12].

The Schizo PCI driver is converted over to use a pre-handler
for the DMA write-sync processing it needs when a device
is behind a PCI->PCI bus deeper than the top-level APB
bridges.

While we're here, clean up all of the action allocation
and handling.  Now, we allocate the irqaction as part of
the bucket->irq_info area.  There is an array of 4 irqaction
(for PCI irq sharing) and a bitmask saying which entries
are active.

The bucket->irq_info is allocated at build_irq() time, not
at request_irq() time.  This simplifies request_irq() and
free_irq() tremendously.

The SMP dynamic IRQ retargetting code got removed in this
change too.  It was disabled for a few months now, and we
can resurrect it in the future if we want.

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 20 insertions, 44 deletions

diff --git a/include/asm-sparc64/irq.h b/include/asm-sparc64/irq.h
index 018e2e46082b..8b70edcb80dc 100644
--- a/include/asm-sparc64/irq.h
+++ b/include/asm-sparc64/irq.h
@@ -16,6 +16,18 @@
 #include <asm/pil.h>
 #include <asm/ptrace.h>
 
+struct ino_bucket;
+
+#define MAX_IRQ_DESC_ACTION	4
+
+struct irq_desc {
+	void			(*pre_handler)(struct ino_bucket *, void *, void *);
+	void			*pre_handler_arg1;
+	void			*pre_handler_arg2;
+	u32			action_active_mask;
+	struct irqaction	action[MAX_IRQ_DESC_ACTION];
+};
+
 /* You should not mess with this directly. That's the job of irq.c.
  *
  * If you make changes here, please update hand coded assembler of
@@ -42,24 +54,11 @@ struct ino_bucket {
 	/* Miscellaneous flags. */
 /*0x06*/unsigned char flags;
 
-	/* This is used to deal with IBF_DMA_SYNC on
-	 * Sabre systems.
-	 */
-/*0x07*/unsigned char synctab_ent;
-
-	/* Reference to handler for this IRQ.  If this is
-	 * non-NULL this means it is active and should be
-	 * serviced.  Else the pending member is set to one
-	 * and later registry of the interrupt checks for
-	 * this condition.
-	 *
-	 * Normally this is just an irq_action structure.
-	 * But, on PCI, if multiple interrupt sources behind
-	 * a bridge have multiple interrupt sources that share
-	 * the same INO bucket, this points to an array of
-	 * pointers to four IRQ action structures.
-	 */
-/*0x08*/void *irq_info;
+	/* Currently unused.  */
+/*0x07*/unsigned char __pad;
+
+	/* Reference to IRQ descriptor for this bucket. */
+/*0x08*/struct irq_desc *irq_info;
 
 	/* Sun5 Interrupt Clear Register. */
 /*0x10*/unsigned long iclr;
@@ -69,12 +68,6 @@ struct ino_bucket {
 
 };
 
-#ifdef CONFIG_PCI
-extern unsigned long pci_dma_wsync;
-extern unsigned long dma_sync_reg_table[256];
-extern unsigned char dma_sync_reg_table_entry;
-#endif
-
 /* IMAP/ICLR register defines */
 #define IMAP_VALID		0x80000000	/* IRQ Enabled		*/
 #define IMAP_TID_UPA		0x7c000000	/* UPA TargetID		*/
@@ -90,11 +83,9 @@ extern unsigned char dma_sync_reg_table_entry;
 #define ICLR_PENDING		0x00000003	/* Pending state	*/
 
 /* Only 8-bits are available, be careful.  -DaveM */
-#define IBF_DMA_SYNC	0x01	/* DMA synchronization behind PCI bridge needed. */
-#define IBF_PCI		0x02	/* Indicates PSYCHO/SABRE/SCHIZO PCI interrupt.	 */
-#define IBF_ACTIVE	0x04	/* This interrupt is active and has a handler.	 */
-#define IBF_MULTI	0x08	/* On PCI, indicates shared bucket.		 */
-#define IBF_INPROGRESS	0x10	/* IRQ is being serviced.			 */
+#define IBF_PCI		0x02	/* PSYCHO/SABRE/SCHIZO PCI interrupt.	 */
+#define IBF_ACTIVE	0x04	/* Interrupt is active and has a handler.*/
+#define IBF_INPROGRESS	0x10	/* IRQ is being serviced.		 */
 
 #define NUM_IVECS	(IMAP_INR + 1)
 extern struct ino_bucket ivector_table[NUM_IVECS];
diff --git a/include/asm-sparc64/signal.h b/include/asm-sparc64/signal.h
index becdf1bc5924..e3059bb4a465 100644
--- a/include/asm-sparc64/signal.h
+++ b/include/asm-sparc64/signal.h
@@ -162,21 +162,6 @@ struct sigstack {
 #define MINSIGSTKSZ	4096
 #define SIGSTKSZ	16384
 
-#ifdef __KERNEL__
-/*
- * DJHR
- * SA_STATIC_ALLOC is used for the SPARC system to indicate that this
- * interrupt handler's irq structure should be statically allocated
- * by the request_irq routine.
- * The alternative is that arch/sparc/kernel/irq.c has carnal knowledge
- * of interrupt usage and that sucks. Also without a flag like this
- * it may be possible for the free_irq routine to attempt to free
- * statically allocated data.. which is NOT GOOD.
- *
- */
-#define SA_STATIC_ALLOC		0x80
-#endif
-
 #include <asm-generic/signal.h>
 
 struct __new_sigaction {