[SPARC64]: Virtualize IRQ numbers.

Inspired by PowerPC XICS interrupt support code.

All IRQs are virtualized in order to keep NR_IRQS from needing
to be too large.  Interrupts on sparc64 are arbitrary 11-bit
values, but we don't need to define NR_IRQS to 2048 if we
virtualize the IRQs.

As PCI and SBUS controller drivers build device IRQs, we divy
out virtual IRQ numbers incrementally starting at 1.  Zero is
a special virtual IRQ used for the timer interrupt.

So device drivers all see virtual IRQs, and all the normal
interfaces such as request_irq(), enable_irq(), etc. translate
that into a real IRQ number in order to configure the IRQ.

At this point knowledge of the struct ino_bucket is almost
entirely contained within arch/sparc64/kernel/irq.c  There are
a few small bits in the PCI controller drivers that need to
be swept away before we can remove ino_bucket's definition
out of asm-sparc64/irq.h and privately into kernel/irq.c

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

1 files changed, 9 insertions, 9 deletions

diff --git a/arch/sparc64/kernel/pci_sabre.c b/arch/sparc64/kernel/pci_sabre.c
index caa7aeed5d14..846c1205aa9a 100644
--- a/arch/sparc64/kernel/pci_sabre.c
+++ b/arch/sparc64/kernel/pci_sabre.c
@@ -544,10 +544,10 @@ static unsigned int sabre_irq_build(struct pci_pbm_info *pbm,
                                     struct pci_dev *pdev,
                                     unsigned int ino)
 {
-        struct ino_bucket *bucket;
         unsigned long imap, iclr;
         unsigned long imap_off, iclr_off;
         int inofixup = 0;
+        int virt_irq;
 
         ino &= PCI_IRQ_INO;
         if (ino < SABRE_ONBOARD_IRQ_BASE) {
@@ -573,23 +573,23 @@ static unsigned int sabre_irq_build(struct pci_pbm_info *pbm,
         if ((ino & 0x20) == 0)
                 inofixup = ino & 0x03;
 
-        bucket = __bucket(build_irq(inofixup, iclr, imap));
-        bucket->flags |= IBF_PCI;
+        virt_irq = build_irq(inofixup, iclr, imap, IBF_PCI);
 
         if (pdev) {
                 struct pcidev_cookie *pcp = pdev->sysdata;
 
                 if (pdev->bus->number != pcp->pbm->pci_first_busno) {
                         struct pci_controller_info *p = pcp->pbm->parent;
-                        struct irq_desc *d = bucket->irq_info;
 
-                        d->pre_handler = sabre_wsync_handler;
-                        d->pre_handler_arg1 = pdev;
-                        d->pre_handler_arg2 = (void *)
-                                p->pbm_A.controller_regs + SABRE_WRSYNC;
+                        irq_install_pre_handler(virt_irq,
+                                                sabre_wsync_handler,
+                                                pdev,
+                                                (void *)
+                                                p->pbm_A.controller_regs +
+                                                SABRE_WRSYNC);
                 }
         }
-        return __irq(bucket);
+        return virt_irq;
 }
 
 /* SABRE error handling support. */