Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1269 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/irq.c b/arch/sparc64/kernel/irq.c
new file mode 100644
index 000000000000..a38cb5036df0
--- /dev/null
+++ b/arch/sparc64/kernel/irq.c
@@ -0,0 +1,1269 @@
+/* $Id: irq.c,v 1.114 2002/01/11 08:45:38 davem Exp $
+ * irq.c: UltraSparc IRQ handling/init/registry.
+ *
+ * Copyright (C) 1997  David S. Miller  (davem@caip.rutgers.edu)
+ * Copyright (C) 1998  Eddie C. Dost    (ecd@skynet.be)
+ * Copyright (C) 1998  Jakub Jelinek    (jj@ultra.linux.cz)
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/ptrace.h>
+#include <linux/errno.h>
+#include <linux/kernel_stat.h>
+#include <linux/signal.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+#include <asm/ptrace.h>
+#include <asm/processor.h>
+#include <asm/atomic.h>
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/sbus.h>
+#include <asm/iommu.h>
+#include <asm/upa.h>
+#include <asm/oplib.h>
+#include <asm/timer.h>
+#include <asm/smp.h>
+#include <asm/starfire.h>
+#include <asm/uaccess.h>
+#include <asm/cache.h>
+#include <asm/cpudata.h>
+
+#ifdef CONFIG_SMP
+static void distribute_irqs(void);
+#endif
+
+/* UPA nodes send interrupt packet to UltraSparc with first data reg
+ * value low 5 (7 on Starfire) bits holding the IRQ identifier being
+ * delivered.  We must translate this into a non-vector IRQ so we can
+ * set the softint on this cpu.
+ *
+ * To make processing these packets efficient and race free we use
+ * an array of irq buckets below.  The interrupt vector handler in
+ * entry.S feeds incoming packets into per-cpu pil-indexed lists.
+ * The IVEC handler does not need to act atomically, the PIL dispatch
+ * code uses CAS to get an atomic snapshot of the list and clear it
+ * at the same time.
+ */
+
+struct ino_bucket ivector_table[NUM_IVECS] __attribute__ ((aligned (SMP_CACHE_BYTES)));
+
+/* This has to be in the main kernel image, it cannot be
+ * turned into per-cpu data.  The reason is that the main
+ * kernel image is locked into the TLB and this structure
+ * is accessed from the vectored interrupt trap handler.  If
+ * access to this structure takes a TLB miss it could cause
+ * the 5-level sparc v9 trap stack to overflow.
+ */
+struct irq_work_struct {
+	unsigned int	irq_worklists[16];
+};
+struct irq_work_struct __irq_work[NR_CPUS];
+#define irq_work(__cpu, __pil)	&(__irq_work[(__cpu)].irq_worklists[(__pil)])
+
+#ifdef CONFIG_PCI
+/* This is a table of physical addresses used to deal with IBF_DMA_SYNC.
+ * It is used for PCI only to synchronize DMA transfers with IRQ delivery
+ * for devices behind busses other than APB on Sabre systems.
+ *
+ * Currently these physical addresses are just config space accesses
+ * to the command register for that device.
+ */
+unsigned long pci_dma_wsync;
+unsigned long dma_sync_reg_table[256];
+unsigned char dma_sync_reg_table_entry = 0;
+#endif
+
+/* This is based upon code in the 32-bit Sparc kernel written mostly by
+ * David Redman (djhr@tadpole.co.uk).
+ */
+#define MAX_STATIC_ALLOC	4
+static struct irqaction static_irqaction[MAX_STATIC_ALLOC];
+static int static_irq_count;
+
+/* This is exported so that fast IRQ handlers can get at it... -DaveM */
+struct irqaction *irq_action[NR_IRQS+1] = {
+	  NULL, NULL, NULL, NULL, NULL, NULL , NULL, NULL,
+	  NULL, NULL, NULL, NULL, NULL, NULL , NULL, NULL
+};
+
+/* This only synchronizes entities which modify IRQ handler
+ * state and some selected user-level spots that want to
+ * read things in the table.  IRQ handler processing orders
+ * its' accesses such that no locking is needed.
+ */
+static DEFINE_SPINLOCK(irq_action_lock);
+
+static void register_irq_proc (unsigned int irq);
+
+/*
+ * Upper 2b of irqaction->flags holds the ino.
+ * irqaction->mask holds the smp affinity information.
+ */
+#define put_ino_in_irqaction(action, irq) \
+	action->flags &= 0xffffffffffffUL; \
+	if (__bucket(irq) == &pil0_dummy_bucket) \
+		action->flags |= 0xdeadUL << 48;  \
+	else \
+		action->flags |= __irq_ino(irq) << 48;
+#define get_ino_in_irqaction(action)	(action->flags >> 48)
+
+#define put_smpaff_in_irqaction(action, smpaff)	(action)->mask = (smpaff)
+#define get_smpaff_in_irqaction(action) 	((action)->mask)
+
+int show_interrupts(struct seq_file *p, void *v)
+{
+	unsigned long flags;
+	int i = *(loff_t *) v;
+	struct irqaction *action;
+#ifdef CONFIG_SMP
+	int j;
+#endif
+
+	spin_lock_irqsave(&irq_action_lock, flags);
+	if (i <= NR_IRQS) {
+		if (!(action = *(i + irq_action)))
+			goto out_unlock;
+		seq_printf(p, "%3d: ", i);
+#ifndef CONFIG_SMP
+		seq_printf(p, "%10u ", kstat_irqs(i));
+#else
+		for (j = 0; j < NR_CPUS; j++) {
+			if (!cpu_online(j))
+				continue;
+			seq_printf(p, "%10u ",
+				   kstat_cpu(j).irqs[i]);
+		}
+#endif
+		seq_printf(p, " %s:%lx", action->name,
+			   get_ino_in_irqaction(action));
+		for (action = action->next; action; action = action->next) {
+			seq_printf(p, ", %s:%lx", action->name,
+				   get_ino_in_irqaction(action));
+		}
+		seq_putc(p, '\n');
+	}
+out_unlock:
+	spin_unlock_irqrestore(&irq_action_lock, flags);
+
+	return 0;
+}
+
+/* Now these are always passed a true fully specified sun4u INO. */
+void enable_irq(unsigned int irq)
+{
+	struct ino_bucket *bucket = __bucket(irq);
+	unsigned long imap;
+	unsigned long tid;
+
+	imap = bucket->imap;
+	if (imap == 0UL)
+		return;
+
+	preempt_disable();
+
+	if (tlb_type == cheetah || tlb_type == cheetah_plus) {
+		unsigned long ver;
+
+		__asm__ ("rdpr %%ver, %0" : "=r" (ver));
+		if ((ver >> 32) == 0x003e0016) {
+			/* We set it to our JBUS ID. */
+			__asm__ __volatile__("ldxa [%%g0] %1, %0"
+					     : "=r" (tid)
+					     : "i" (ASI_JBUS_CONFIG));
+			tid = ((tid & (0x1fUL<<17)) << 9);
+			tid &= IMAP_TID_JBUS;
+		} else {
+			/* We set it to our Safari AID. */
+			__asm__ __volatile__("ldxa [%%g0] %1, %0"
+					     : "=r" (tid)
+					     : "i" (ASI_SAFARI_CONFIG));
+			tid = ((tid & (0x3ffUL<<17)) << 9);
+			tid &= IMAP_AID_SAFARI;
+		}
+	} else if (this_is_starfire == 0) {
+		/* We set it to our UPA MID. */
+		__asm__ __volatile__("ldxa [%%g0] %1, %0"
+				     : "=r" (tid)
+				     : "i" (ASI_UPA_CONFIG));
+		tid = ((tid & UPA_CONFIG_MID) << 9);
+		tid &= IMAP_TID_UPA;
+	} else {
+		tid = (starfire_translate(imap, smp_processor_id()) << 26);
+		tid &= IMAP_TID_UPA;
+	}
+
+	/* NOTE NOTE NOTE, IGN and INO are read-only, IGN is a product
+	 * of this SYSIO's preconfigured IGN in the SYSIO Control
+	 * Register, the hardware just mirrors that value here.
+	 * However for Graphics and UPA Slave devices the full
+	 * IMAP_INR field can be set by the programmer here.
+	 *
+	 * Things like FFB can now be handled via the new IRQ mechanism.
+	 */
+	upa_writel(tid | IMAP_VALID, imap);
+
+	preempt_enable();
+}
+
+/* This now gets passed true ino's as well. */
+void disable_irq(unsigned int irq)
+{
+	struct ino_bucket *bucket = __bucket(irq);
+	unsigned long imap;
+
+	imap = bucket->imap;
+	if (imap != 0UL) {
+		u32 tmp;
+
+		/* NOTE: We do not want to futz with the IRQ clear registers
+		 *       and move the state to IDLE, the SCSI code does call
+		 *       disable_irq() to assure atomicity in the queue cmd
+		 *       SCSI adapter driver code.  Thus we'd lose interrupts.
+		 */
+		tmp = upa_readl(imap);
+		tmp &= ~IMAP_VALID;
+		upa_writel(tmp, imap);
+	}
+}
+
+/* The timer is the one "weird" interrupt which is generated by
+ * the CPU %tick register and not by some normal vectored interrupt
+ * source.  To handle this special case, we use this dummy INO bucket.
+ */
+static struct ino_bucket pil0_dummy_bucket = {
+	0,	/* irq_chain */
+	0,	/* pil */
+	0,	/* pending */
+	0,	/* flags */
+	0,	/* __unused */
+	NULL,	/* irq_info */
+	0UL,	/* iclr */
+	0UL,	/* imap */
+};
+
+unsigned int build_irq(int pil, int inofixup, unsigned long iclr, unsigned long imap)
+{
+	struct ino_bucket *bucket;
+	int ino;
+
+	if (pil == 0) {
+		if (iclr != 0UL || imap != 0UL) {
+			prom_printf("Invalid dummy bucket for PIL0 (%lx:%lx)\n",
+				    iclr, imap);
+			prom_halt();
+		}
+		return __irq(&pil0_dummy_bucket);
+	}
+
+	/* RULE: Both must be specified in all other cases. */
+	if (iclr == 0UL || imap == 0UL) {
+		prom_printf("Invalid build_irq %d %d %016lx %016lx\n",
+			    pil, inofixup, iclr, imap);
+		prom_halt();
+	}
+	
+	ino = (upa_readl(imap) & (IMAP_IGN | IMAP_INO)) + inofixup;
+	if (ino > NUM_IVECS) {
+		prom_printf("Invalid INO %04x (%d:%d:%016lx:%016lx)\n",
+			    ino, pil, inofixup, iclr, imap);
+		prom_halt();
+	}
+
+	/* Ok, looks good, set it up.  Don't touch the irq_chain or
+	 * the pending flag.
+	 */
+	bucket = &ivector_table[ino];
+	if ((bucket->flags & IBF_ACTIVE) ||
+	    (bucket->irq_info != NULL)) {
+		/* This is a gross fatal error if it happens here. */
+		prom_printf("IRQ: Trying to reinit INO bucket, fatal error.\n");
+		prom_printf("IRQ: Request INO %04x (%d:%d:%016lx:%016lx)\n",
+			    ino, pil, inofixup, iclr, imap);
+		prom_printf("IRQ: Existing (%d:%016lx:%016lx)\n",
+			    bucket->pil, bucket->iclr, bucket->imap);
+		prom_printf("IRQ: Cannot continue, halting...\n");
+		prom_halt();
+	}
+	bucket->imap  = imap;
+	bucket->iclr  = iclr;
+	bucket->pil   = pil;
+	bucket->flags = 0;
+
+	bucket->irq_info = NULL;
+
+	return __irq(bucket);
+}
+
+static void atomic_bucket_insert(struct ino_bucket *bucket)
+{
+	unsigned long pstate;
+	unsigned int *ent;
+
+	__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
+	__asm__ __volatile__("wrpr %0, %1, %%pstate"
+			     : : "r" (pstate), "i" (PSTATE_IE));
+	ent = irq_work(smp_processor_id(), bucket->pil);
+	bucket->irq_chain = *ent;
+	*ent = __irq(bucket);
+	__asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate));
+}
+
+int request_irq(unsigned int irq, irqreturn_t (*handler)(int, void *, struct pt_regs *),
+		unsigned long irqflags, const char *name, void *dev_id)
+{
+	struct irqaction *action, *tmp = NULL;
+	struct ino_bucket *bucket = __bucket(irq);
+	unsigned long flags;
+	int pending = 0;
+
+	if ((bucket != &pil0_dummy_bucket) &&
+	    (bucket < &ivector_table[0] ||
+	     bucket >= &ivector_table[NUM_IVECS])) {
+		unsigned int *caller;
+
+		__asm__ __volatile__("mov %%i7, %0" : "=r" (caller));
+		printk(KERN_CRIT "request_irq: Old style IRQ registry attempt "
+		       "from %p, irq %08x.\n", caller, irq);
+		return -EINVAL;
+	}	
+	if (!handler)
+	    return -EINVAL;
+
+	if ((bucket != &pil0_dummy_bucket) && (irqflags & SA_SAMPLE_RANDOM)) {
+		/*
+	 	 * This function might sleep, we want to call it first,
+	 	 * outside of the atomic block. In SA_STATIC_ALLOC case,
+		 * random driver's kmalloc will fail, but it is safe.
+		 * If already initialized, random driver will not reinit.
+	 	 * Yes, this might clear the entropy pool if the wrong
+	 	 * driver is attempted to be loaded, without actually
+	 	 * installing a new handler, but is this really a problem,
+	 	 * only the sysadmin is able to do this.
+	 	 */
+		rand_initialize_irq(irq);
+	}
+
+	spin_lock_irqsave(&irq_action_lock, flags);
+
+	action = *(bucket->pil + irq_action);
+	if (action) {
+		if ((action->flags & SA_SHIRQ) && (irqflags & SA_SHIRQ))
+			for (tmp = action; tmp->next; tmp = tmp->next)
+				;
+		else {
+			spin_unlock_irqrestore(&irq_action_lock, flags);
+			return -EBUSY;
+		}
+		action = NULL;		/* Or else! */
+	}
+
+	/* If this is flagged as statically allocated then we use our
+	 * private struct which is never freed.
+	 */
+	if (irqflags & SA_STATIC_ALLOC) {
+	    if (static_irq_count < MAX_STATIC_ALLOC)
+		action = &static_irqaction[static_irq_count++];
+	    else
+		printk("Request for IRQ%d (%s) SA_STATIC_ALLOC failed "
+		       "using kmalloc\n", irq, name);
+	}	
+	if (action == NULL)
+	    action = (struct irqaction *)kmalloc(sizeof(struct irqaction),
+						 GFP_ATOMIC);
+	
+	if (!action) { 
+		spin_unlock_irqrestore(&irq_action_lock, flags);
+		return -ENOMEM;
+	}
+
+	if (bucket == &pil0_dummy_bucket) {
+		bucket->irq_info = action;
+		bucket->flags |= IBF_ACTIVE;
+	} else {
+		if ((bucket->flags & IBF_ACTIVE) != 0) {
+			void *orig = bucket->irq_info;
+			void **vector = NULL;
+
+			if ((bucket->flags & IBF_PCI) == 0) {
+				printk("IRQ: Trying to share non-PCI bucket.\n");
+				goto free_and_ebusy;
+			}
+			if ((bucket->flags & IBF_MULTI) == 0) {
+				vector = kmalloc(sizeof(void *) * 4, GFP_ATOMIC);
+				if (vector == NULL)
+					goto free_and_enomem;
+
+				/* We might have slept. */
+				if ((bucket->flags & IBF_MULTI) != 0) {
+					int ent;
+
+					kfree(vector);
+					vector = (void **)bucket->irq_info;
+					for(ent = 0; ent < 4; ent++) {
+						if (vector[ent] == NULL) {
+							vector[ent] = action;
+							break;
+						}
+					}
+					if (ent == 4)
+						goto free_and_ebusy;
+				} else {
+					vector[0] = orig;
+					vector[1] = action;
+					vector[2] = NULL;
+					vector[3] = NULL;
+					bucket->irq_info = vector;
+					bucket->flags |= IBF_MULTI;
+				}
+			} else {
+				int ent;
+
+				vector = (void **)orig;
+				for (ent = 0; ent < 4; ent++) {
+					if (vector[ent] == NULL) {
+						vector[ent] = action;
+						break;
+					}
+				}
+				if (ent == 4)
+					goto free_and_ebusy;
+			}
+		} else {
+			bucket->irq_info = action;
+			bucket->flags |= IBF_ACTIVE;
+		}
+		pending = bucket->pending;
+		if (pending)
+			bucket->pending = 0;
+	}
+
+	action->handler = handler;
+	action->flags = irqflags;
+	action->name = name;
+	action->next = NULL;
+	action->dev_id = dev_id;
+	put_ino_in_irqaction(action, irq);
+	put_smpaff_in_irqaction(action, CPU_MASK_NONE);
+
+	if (tmp)
+		tmp->next = action;
+	else
+		*(bucket->pil + irq_action) = action;
+
+	enable_irq(irq);
+
+	/* We ate the IVEC already, this makes sure it does not get lost. */
+	if (pending) {
+		atomic_bucket_insert(bucket);
+		set_softint(1 << bucket->pil);
+	}
+	spin_unlock_irqrestore(&irq_action_lock, flags);
+	if ((bucket != &pil0_dummy_bucket) && (!(irqflags & SA_STATIC_ALLOC)))
+		register_irq_proc(__irq_ino(irq));
+
+#ifdef CONFIG_SMP
+	distribute_irqs();
+#endif
+	return 0;
+
+free_and_ebusy:
+	kfree(action);
+	spin_unlock_irqrestore(&irq_action_lock, flags);
+	return -EBUSY;
+
+free_and_enomem:
+	kfree(action);
+	spin_unlock_irqrestore(&irq_action_lock, flags);
+	return -ENOMEM;
+}
+
+EXPORT_SYMBOL(request_irq);
+
+void free_irq(unsigned int irq, void *dev_id)
+{
+	struct irqaction *action;
+	struct irqaction *tmp = NULL;
+	unsigned long flags;
+	struct ino_bucket *bucket = __bucket(irq), *bp;
+
+	if ((bucket != &pil0_dummy_bucket) &&
+	    (bucket < &ivector_table[0] ||
+	     bucket >= &ivector_table[NUM_IVECS])) {
+		unsigned int *caller;
+
+		__asm__ __volatile__("mov %%i7, %0" : "=r" (caller));
+		printk(KERN_CRIT "free_irq: Old style IRQ removal attempt "
+		       "from %p, irq %08x.\n", caller, irq);
+		return;
+	}
+	
+	spin_lock_irqsave(&irq_action_lock, flags);
+
+	action = *(bucket->pil + irq_action);
+	if (!action->handler) {
+		printk("Freeing free IRQ %d\n", bucket->pil);
+		return;
+	}
+	if (dev_id) {
+		for ( ; action; action = action->next) {
+			if (action->dev_id == dev_id)
+				break;
+			tmp = action;
+		}
+		if (!action) {
+			printk("Trying to free free shared IRQ %d\n", bucket->pil);
+			spin_unlock_irqrestore(&irq_action_lock, flags);
+			return;
+		}
+	} else if (action->flags & SA_SHIRQ) {
+		printk("Trying to free shared IRQ %d with NULL device ID\n", bucket->pil);
+		spin_unlock_irqrestore(&irq_action_lock, flags);
+		return;
+	}
+
+	if (action->flags & SA_STATIC_ALLOC) {
+		printk("Attempt to free statically allocated IRQ %d (%s)\n",
+		       bucket->pil, action->name);
+		spin_unlock_irqrestore(&irq_action_lock, flags);
+		return;
+	}
+
+	if (action && tmp)
+		tmp->next = action->next;
+	else
+		*(bucket->pil + irq_action) = action->next;
+
+	spin_unlock_irqrestore(&irq_action_lock, flags);
+
+	synchronize_irq(irq);
+
+	spin_lock_irqsave(&irq_action_lock, flags);
+
+	if (bucket != &pil0_dummy_bucket) {
+		unsigned long imap = bucket->imap;
+		void **vector, *orig;
+		int ent;
+
+		orig = bucket->irq_info;
+		vector = (void **)orig;
+
+		if ((bucket->flags & IBF_MULTI) != 0) {
+			int other = 0;
+			void *orphan = NULL;
+			for (ent = 0; ent < 4; ent++) {
+				if (vector[ent] == action)
+					vector[ent] = NULL;
+				else if (vector[ent] != NULL) {
+					orphan = vector[ent];
+					other++;
+				}
+			}
+
+			/* Only free when no other shared irq
+			 * uses this bucket.
+			 */
+			if (other) {
+				if (other == 1) {
+					/* Convert back to non-shared bucket. */
+					bucket->irq_info = orphan;
+					bucket->flags &= ~(IBF_MULTI);
+					kfree(vector);
+				}
+				goto out;
+			}
+		} else {
+			bucket->irq_info = NULL;
+		}
+
+		/* This unique interrupt source is now inactive. */
+		bucket->flags &= ~IBF_ACTIVE;
+
+		/* See if any other buckets share this bucket's IMAP
+		 * and are still active.
+		 */
+		for (ent = 0; ent < NUM_IVECS; ent++) {
+			bp = &ivector_table[ent];
+			if (bp != bucket	&&
+			    bp->imap == imap	&&
+			    (bp->flags & IBF_ACTIVE) != 0)
+				break;
+		}
+
+		/* Only disable when no other sub-irq levels of
+		 * the same IMAP are active.
+		 */
+		if (ent == NUM_IVECS)
+			disable_irq(irq);
+	}
+
+out:
+	kfree(action);
+	spin_unlock_irqrestore(&irq_action_lock, flags);
+}
+
+EXPORT_SYMBOL(free_irq);
+
+#ifdef CONFIG_SMP
+void synchronize_irq(unsigned int irq)
+{
+	struct ino_bucket *bucket = __bucket(irq);
+
+#if 0
+	/* The following is how I wish I could implement this.
+	 * Unfortunately the ICLR registers are read-only, you can
+	 * only write ICLR_foo values to them.  To get the current
+	 * IRQ status you would need to get at the IRQ diag registers
+	 * in the PCI/SBUS controller and the layout of those vary
+	 * from one controller to the next, sigh... -DaveM
+	 */
+	unsigned long iclr = bucket->iclr;
+
+	while (1) {
+		u32 tmp = upa_readl(iclr);
+		
+		if (tmp == ICLR_TRANSMIT ||
+		    tmp == ICLR_PENDING) {
+			cpu_relax();
+			continue;
+		}
+		break;
+	}
+#else
+	/* So we have to do this with a INPROGRESS bit just like x86.  */
+	while (bucket->flags & IBF_INPROGRESS)
+		cpu_relax();
+#endif
+}
+#endif /* CONFIG_SMP */
+
+void catch_disabled_ivec(struct pt_regs *regs)
+{
+	int cpu = smp_processor_id();
+	struct ino_bucket *bucket = __bucket(*irq_work(cpu, 0));
+
+	/* We can actually see this on Ultra/PCI PCI cards, which are bridges
+	 * to other devices.  Here a single IMAP enabled potentially multiple
+	 * unique interrupt sources (which each do have a unique ICLR register.
+	 *
+	 * So what we do is just register that the IVEC arrived, when registered
+	 * for real the request_irq() code will check the bit and signal
+	 * a local CPU interrupt for it.
+	 */
+#if 0
+	printk("IVEC: Spurious interrupt vector (%x) received at (%016lx)\n",
+	       bucket - &ivector_table[0], regs->tpc);
+#endif
+	*irq_work(cpu, 0) = 0;
+	bucket->pending = 1;
+}
+
+/* Tune this... */
+#define FORWARD_VOLUME		12
+
+#ifdef CONFIG_SMP
+
+static inline void redirect_intr(int cpu, struct ino_bucket *bp)
+{
+	/* Ok, here is what is going on:
+	 * 1) Retargeting IRQs on Starfire is very
+	 *    expensive so just forget about it on them.
+	 * 2) Moving around very high priority interrupts
+	 *    is a losing game.
+	 * 3) If the current cpu is idle, interrupts are
+	 *    useful work, so keep them here.  But do not
+	 *    pass to our neighbour if he is not very idle.
+	 * 4) If sysadmin explicitly asks for directed intrs,
+	 *    Just Do It.
+	 */
+	struct irqaction *ap = bp->irq_info;
+	cpumask_t cpu_mask;
+	unsigned int buddy, ticks;
+
+	cpu_mask = get_smpaff_in_irqaction(ap);
+	cpus_and(cpu_mask, cpu_mask, cpu_online_map);
+	if (cpus_empty(cpu_mask))
+		cpu_mask = cpu_online_map;
+
+	if (this_is_starfire != 0 ||
+	    bp->pil >= 10 || current->pid == 0)
+		goto out;
+
+	/* 'cpu' is the MID (ie. UPAID), calculate the MID
+	 * of our buddy.
+	 */
+	buddy = cpu + 1;
+	if (buddy >= NR_CPUS)
+		buddy = 0;
+
+	ticks = 0;
+	while (!cpu_isset(buddy, cpu_mask)) {
+		if (++buddy >= NR_CPUS)
+			buddy = 0;
+		if (++ticks > NR_CPUS) {
+			put_smpaff_in_irqaction(ap, CPU_MASK_NONE);
+			goto out;
+		}
+	}
+
+	if (buddy == cpu)
+		goto out;
+
+	/* Voo-doo programming. */
+	if (cpu_data(buddy).idle_volume < FORWARD_VOLUME)
+		goto out;
+
+	/* This just so happens to be correct on Cheetah
+	 * at the moment.
+	 */
+	buddy <<= 26;
+
+	/* Push it to our buddy. */
+	upa_writel(buddy | IMAP_VALID, bp->imap);
+
+out:
+	return;
+}
+
+#endif
+
+void handler_irq(int irq, struct pt_regs *regs)
+{
+	struct ino_bucket *bp, *nbp;
+	int cpu = smp_processor_id();
+
+#ifndef CONFIG_SMP
+	/*
+	 * Check for TICK_INT on level 14 softint.
+	 */
+	{
+		unsigned long clr_mask = 1 << irq;
+		unsigned long tick_mask = tick_ops->softint_mask;
+
+		if ((irq == 14) && (get_softint() & tick_mask)) {
+			irq = 0;
+			clr_mask = tick_mask;
+		}
+		clear_softint(clr_mask);
+	}
+#else
+	int should_forward = 1;
+
+	clear_softint(1 << irq);
+#endif
+
+	irq_enter();
+	kstat_this_cpu.irqs[irq]++;
+
+	/* Sliiiick... */
+#ifndef CONFIG_SMP
+	bp = ((irq != 0) ?
+	      __bucket(xchg32(irq_work(cpu, irq), 0)) :
+	      &pil0_dummy_bucket);
+#else
+	bp = __bucket(xchg32(irq_work(cpu, irq), 0));
+#endif
+	for ( ; bp != NULL; bp = nbp) {
+		unsigned char flags = bp->flags;
+		unsigned char random = 0;
+
+		nbp = __bucket(bp->irq_chain);
+		bp->irq_chain = 0;
+
+		bp->flags |= IBF_INPROGRESS;
+
+		if ((flags & IBF_ACTIVE) != 0) {
+#ifdef CONFIG_PCI
+			if ((flags & IBF_DMA_SYNC) != 0) {
+				upa_readl(dma_sync_reg_table[bp->synctab_ent]);
+				upa_readq(pci_dma_wsync);
+			}
+#endif
+			if ((flags & IBF_MULTI) == 0) {
+				struct irqaction *ap = bp->irq_info;
+				int ret;
+
+				ret = ap->handler(__irq(bp), ap->dev_id, regs);
+				if (ret == IRQ_HANDLED)
+					random |= ap->flags;
+			} else {
+				void **vector = (void **)bp->irq_info;
+				int ent;
+				for (ent = 0; ent < 4; ent++) {
+					struct irqaction *ap = vector[ent];
+					if (ap != NULL) {
+						int ret;
+
+						ret = ap->handler(__irq(bp),
+								  ap->dev_id,
+								  regs);
+						if (ret == IRQ_HANDLED)
+							random |= ap->flags;
+					}
+				}
+			}
+			/* Only the dummy bucket lacks IMAP/ICLR. */
+			if (bp->pil != 0) {
+#ifdef CONFIG_SMP
+				if (should_forward) {
+					redirect_intr(cpu, bp);
+					should_forward = 0;
+				}
+#endif
+				upa_writel(ICLR_IDLE, bp->iclr);
+
+				/* Test and add entropy */
+				if (random & SA_SAMPLE_RANDOM)
+					add_interrupt_randomness(irq);
+			}
+		} else
+			bp->pending = 1;
+
+		bp->flags &= ~IBF_INPROGRESS;
+	}
+	irq_exit();
+}
+
+#ifdef CONFIG_BLK_DEV_FD
+extern void floppy_interrupt(int irq, void *dev_cookie, struct pt_regs *regs);
+
+void sparc_floppy_irq(int irq, void *dev_cookie, struct pt_regs *regs)
+{
+	struct irqaction *action = *(irq + irq_action);
+	struct ino_bucket *bucket;
+	int cpu = smp_processor_id();
+
+	irq_enter();
+	kstat_this_cpu.irqs[irq]++;
+
+	*(irq_work(cpu, irq)) = 0;
+	bucket = get_ino_in_irqaction(action) + ivector_table;
+
+	bucket->flags |= IBF_INPROGRESS;
+
+	floppy_interrupt(irq, dev_cookie, regs);
+	upa_writel(ICLR_IDLE, bucket->iclr);
+
+	bucket->flags &= ~IBF_INPROGRESS;
+
+	irq_exit();
+}
+#endif
+
+/* The following assumes that the branch lies before the place we
+ * are branching to.  This is the case for a trap vector...
+ * You have been warned.
+ */
+#define SPARC_BRANCH(dest_addr, inst_addr) \
+          (0x10800000 | ((((dest_addr)-(inst_addr))>>2)&0x3fffff))
+
+#define SPARC_NOP (0x01000000)
+
+static void install_fast_irq(unsigned int cpu_irq,
+			     irqreturn_t (*handler)(int, void *, struct pt_regs *))
+{
+	extern unsigned long sparc64_ttable_tl0;
+	unsigned long ttent = (unsigned long) &sparc64_ttable_tl0;
+	unsigned int *insns;
+
+	ttent += 0x820;
+	ttent += (cpu_irq - 1) << 5;
+	insns = (unsigned int *) ttent;
+	insns[0] = SPARC_BRANCH(((unsigned long) handler),
+				((unsigned long)&insns[0]));
+	insns[1] = SPARC_NOP;
+	__asm__ __volatile__("membar #StoreStore; flush %0" : : "r" (ttent));
+}
+
+int request_fast_irq(unsigned int irq,
+		     irqreturn_t (*handler)(int, void *, struct pt_regs *),
+		     unsigned long irqflags, const char *name, void *dev_id)
+{
+	struct irqaction *action;
+	struct ino_bucket *bucket = __bucket(irq);
+	unsigned long flags;
+
+	/* No pil0 dummy buckets allowed here. */
+	if (bucket < &ivector_table[0] ||
+	    bucket >= &ivector_table[NUM_IVECS]) {
+		unsigned int *caller;
+
+		__asm__ __volatile__("mov %%i7, %0" : "=r" (caller));
+		printk(KERN_CRIT "request_fast_irq: Old style IRQ registry attempt "
+		       "from %p, irq %08x.\n", caller, irq);
+		return -EINVAL;
+	}	
+	
+	if (!handler)
+		return -EINVAL;
+
+	if ((bucket->pil == 0) || (bucket->pil == 14)) {
+		printk("request_fast_irq: Trying to register shared IRQ 0 or 14.\n");
+		return -EBUSY;
+	}
+
+	spin_lock_irqsave(&irq_action_lock, flags);
+
+	action = *(bucket->pil + irq_action);
+	if (action) {
+		if (action->flags & SA_SHIRQ)
+			panic("Trying to register fast irq when already shared.\n");
+		if (irqflags & SA_SHIRQ)
+			panic("Trying to register fast irq as shared.\n");
+		printk("request_fast_irq: Trying to register yet already owned.\n");
+		spin_unlock_irqrestore(&irq_action_lock, flags);
+		return -EBUSY;
+	}
+
+	/*
+	 * We do not check for SA_SAMPLE_RANDOM in this path. Neither do we
+	 * support smp intr affinity in this path.
+	 */
+	if (irqflags & SA_STATIC_ALLOC) {
+		if (static_irq_count < MAX_STATIC_ALLOC)
+			action = &static_irqaction[static_irq_count++];
+		else
+			printk("Request for IRQ%d (%s) SA_STATIC_ALLOC failed "
+			       "using kmalloc\n", bucket->pil, name);
+	}
+	if (action == NULL)
+		action = (struct irqaction *)kmalloc(sizeof(struct irqaction),
+						     GFP_ATOMIC);
+	if (!action) {
+		spin_unlock_irqrestore(&irq_action_lock, flags);
+		return -ENOMEM;
+	}
+	install_fast_irq(bucket->pil, handler);
+
+	bucket->irq_info = action;
+	bucket->flags |= IBF_ACTIVE;
+
+	action->handler = handler;
+	action->flags = irqflags;
+	action->dev_id = NULL;
+	action->name = name;
+	action->next = NULL;
+	put_ino_in_irqaction(action, irq);
+	put_smpaff_in_irqaction(action, CPU_MASK_NONE);
+
+	*(bucket->pil + irq_action) = action;
+	enable_irq(irq);
+
+	spin_unlock_irqrestore(&irq_action_lock, flags);
+
+#ifdef CONFIG_SMP
+	distribute_irqs();
+#endif
+	return 0;
+}
+
+/* We really don't need these at all on the Sparc.  We only have
+ * stubs here because they are exported to modules.
+ */
+unsigned long probe_irq_on(void)
+{
+	return 0;
+}
+
+EXPORT_SYMBOL(probe_irq_on);
+
+int probe_irq_off(unsigned long mask)
+{
+	return 0;
+}
+
+EXPORT_SYMBOL(probe_irq_off);
+
+#ifdef CONFIG_SMP
+static int retarget_one_irq(struct irqaction *p, int goal_cpu)
+{
+	struct ino_bucket *bucket = get_ino_in_irqaction(p) + ivector_table;
+	unsigned long imap = bucket->imap;
+	unsigned int tid;
+
+	while (!cpu_online(goal_cpu)) {
+		if (++goal_cpu >= NR_CPUS)
+			goal_cpu = 0;
+	}
+
+	if (tlb_type == cheetah || tlb_type == cheetah_plus) {
+		tid = goal_cpu << 26;
+		tid &= IMAP_AID_SAFARI;
+	} else if (this_is_starfire == 0) {
+		tid = goal_cpu << 26;
+		tid &= IMAP_TID_UPA;
+	} else {
+		tid = (starfire_translate(imap, goal_cpu) << 26);
+		tid &= IMAP_TID_UPA;
+	}
+	upa_writel(tid | IMAP_VALID, imap);
+
+	while (!cpu_online(goal_cpu)) {
+		if (++goal_cpu >= NR_CPUS)
+			goal_cpu = 0;
+	}
+
+	return goal_cpu;
+}
+
+/* Called from request_irq. */
+static void distribute_irqs(void)
+{
+	unsigned long flags;
+	int cpu, level;
+
+	spin_lock_irqsave(&irq_action_lock, flags);
+	cpu = 0;
+
+	/*
+	 * Skip the timer at [0], and very rare error/power intrs at [15].
+	 * Also level [12], it causes problems on Ex000 systems.
+	 */
+	for (level = 1; level < NR_IRQS; level++) {
+		struct irqaction *p = irq_action[level];
+		if (level == 12) continue;
+		while(p) {
+			cpu = retarget_one_irq(p, cpu);
+			p = p->next;
+		}
+	}
+	spin_unlock_irqrestore(&irq_action_lock, flags);
+}
+#endif
+
+
+struct sun5_timer *prom_timers;
+static u64 prom_limit0, prom_limit1;
+
+static void map_prom_timers(void)
+{
+	unsigned int addr[3];
+	int tnode, err;
+
+	/* PROM timer node hangs out in the top level of device siblings... */
+	tnode = prom_finddevice("/counter-timer");
+
+	/* Assume if node is not present, PROM uses different tick mechanism
+	 * which we should not care about.
+	 */
+	if (tnode == 0 || tnode == -1) {
+		prom_timers = (struct sun5_timer *) 0;
+		return;
+	}
+
+	/* If PROM is really using this, it must be mapped by him. */
+	err = prom_getproperty(tnode, "address", (char *)addr, sizeof(addr));
+	if (err == -1) {
+		prom_printf("PROM does not have timer mapped, trying to continue.\n");
+		prom_timers = (struct sun5_timer *) 0;
+		return;
+	}
+	prom_timers = (struct sun5_timer *) ((unsigned long)addr[0]);
+}
+
+static void kill_prom_timer(void)
+{
+	if (!prom_timers)
+		return;
+
+	/* Save them away for later. */
+	prom_limit0 = prom_timers->limit0;
+	prom_limit1 = prom_timers->limit1;
+
+	/* Just as in sun4c/sun4m PROM uses timer which ticks at IRQ 14.
+	 * We turn both off here just to be paranoid.
+	 */
+	prom_timers->limit0 = 0;
+	prom_timers->limit1 = 0;
+
+	/* Wheee, eat the interrupt packet too... */
+	__asm__ __volatile__(
+"	mov	0x40, %%g2\n"
+"	ldxa	[%%g0] %0, %%g1\n"
+"	ldxa	[%%g2] %1, %%g1\n"
+"	stxa	%%g0, [%%g0] %0\n"
+"	membar	#Sync\n"
+	: /* no outputs */
+	: "i" (ASI_INTR_RECEIVE), "i" (ASI_INTR_R)
+	: "g1", "g2");
+}
+
+void enable_prom_timer(void)
+{
+	if (!prom_timers)
+		return;
+
+	/* Set it to whatever was there before. */
+	prom_timers->limit1 = prom_limit1;
+	prom_timers->count1 = 0;
+	prom_timers->limit0 = prom_limit0;
+	prom_timers->count0 = 0;
+}
+
+void init_irqwork_curcpu(void)
+{
+	register struct irq_work_struct *workp asm("o2");
+	register unsigned long tmp asm("o3");
+	int cpu = hard_smp_processor_id();
+
+	memset(__irq_work + cpu, 0, sizeof(*workp));
+
+	/* Make sure we are called with PSTATE_IE disabled.  */
+	__asm__ __volatile__("rdpr	%%pstate, %0\n\t"
+			     : "=r" (tmp));
+	if (tmp & PSTATE_IE) {
+		prom_printf("BUG: init_irqwork_curcpu() called with "
+			    "PSTATE_IE enabled, bailing.\n");
+		__asm__ __volatile__("mov	%%i7, %0\n\t"
+				     : "=r" (tmp));
+		prom_printf("BUG: Called from %lx\n", tmp);
+		prom_halt();
+	}
+
+	/* Set interrupt globals.  */
+	workp = &__irq_work[cpu];
+	__asm__ __volatile__(
+	"rdpr	%%pstate, %0\n\t"
+	"wrpr	%0, %1, %%pstate\n\t"
+	"mov	%2, %%g6\n\t"
+	"wrpr	%0, 0x0, %%pstate\n\t"
+	: "=&r" (tmp)
+	: "i" (PSTATE_IG), "r" (workp));
+}
+
+/* Only invoked on boot processor. */
+void __init init_IRQ(void)
+{
+	map_prom_timers();
+	kill_prom_timer();
+	memset(&ivector_table[0], 0, sizeof(ivector_table));
+
+	/* We need to clear any IRQ's pending in the soft interrupt
+	 * registers, a spurious one could be left around from the
+	 * PROM timer which we just disabled.
+	 */
+	clear_softint(get_softint());
+
+	/* Now that ivector table is initialized, it is safe
+	 * to receive IRQ vector traps.  We will normally take
+	 * one or two right now, in case some device PROM used
+	 * to boot us wants to speak to us.  We just ignore them.
+	 */
+	__asm__ __volatile__("rdpr	%%pstate, %%g1\n\t"
+			     "or	%%g1, %0, %%g1\n\t"
+			     "wrpr	%%g1, 0x0, %%pstate"
+			     : /* No outputs */
+			     : "i" (PSTATE_IE)
+			     : "g1");
+}
+
+static struct proc_dir_entry * root_irq_dir;
+static struct proc_dir_entry * irq_dir [NUM_IVECS];
+
+#ifdef CONFIG_SMP
+
+static int irq_affinity_read_proc (char *page, char **start, off_t off,
+			int count, int *eof, void *data)
+{
+	struct ino_bucket *bp = ivector_table + (long)data;
+	struct irqaction *ap = bp->irq_info;
+	cpumask_t mask;
+	int len;
+
+	mask = get_smpaff_in_irqaction(ap);
+	if (cpus_empty(mask))
+		mask = cpu_online_map;
+
+	len = cpumask_scnprintf(page, count, mask);
+	if (count - len < 2)
+		return -EINVAL;
+	len += sprintf(page + len, "\n");
+	return len;
+}
+
+static inline void set_intr_affinity(int irq, cpumask_t hw_aff)
+{
+	struct ino_bucket *bp = ivector_table + irq;
+
+	/* Users specify affinity in terms of hw cpu ids.
+	 * As soon as we do this, handler_irq() might see and take action.
+	 */
+	put_smpaff_in_irqaction((struct irqaction *)bp->irq_info, hw_aff);
+
+	/* Migration is simply done by the next cpu to service this
+	 * interrupt.
+	 */
+}
+
+static int irq_affinity_write_proc (struct file *file, const char __user *buffer,
+					unsigned long count, void *data)
+{
+	int irq = (long) data, full_count = count, err;
+	cpumask_t new_value;
+
+	err = cpumask_parse(buffer, count, new_value);
+
+	/*
+	 * Do not allow disabling IRQs completely - it's a too easy
+	 * way to make the system unusable accidentally :-) At least
+	 * one online CPU still has to be targeted.
+	 */
+	cpus_and(new_value, new_value, cpu_online_map);
+	if (cpus_empty(new_value))
+		return -EINVAL;
+
+	set_intr_affinity(irq, new_value);
+
+	return full_count;
+}
+
+#endif
+
+#define MAX_NAMELEN 10
+
+static void register_irq_proc (unsigned int irq)
+{
+	char name [MAX_NAMELEN];
+
+	if (!root_irq_dir || irq_dir[irq])
+		return;
+
+	memset(name, 0, MAX_NAMELEN);
+	sprintf(name, "%x", irq);
+
+	/* create /proc/irq/1234 */
+	irq_dir[irq] = proc_mkdir(name, root_irq_dir);
+
+#ifdef CONFIG_SMP
+	/* XXX SMP affinity not supported on starfire yet. */
+	if (this_is_starfire == 0) {
+		struct proc_dir_entry *entry;
+
+		/* create /proc/irq/1234/smp_affinity */
+		entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
+
+		if (entry) {
+			entry->nlink = 1;
+			entry->data = (void *)(long)irq;
+			entry->read_proc = irq_affinity_read_proc;
+			entry->write_proc = irq_affinity_write_proc;
+		}
+	}
+#endif
+}
+
+void init_irq_proc (void)
+{
+	/* create /proc/irq */
+	root_irq_dir = proc_mkdir("irq", NULL);
+}
+