1 files changed, 329 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/iseries/lpevents.c b/arch/powerpc/platforms/iseries/lpevents.c
new file mode 100644
index 00000000000..f8b4155b048
--- /dev/null
+++ b/arch/powerpc/platforms/iseries/lpevents.c
@@ -0,0 +1,329 @@
+/*
+ * Copyright (C) 2001 Mike Corrigan  IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/bootmem.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+
+#include <asm/system.h>
+#include <asm/paca.h>
+#include <asm/iSeries/ItLpQueue.h>
+#include <asm/iSeries/HvLpEvent.h>
+#include <asm/iSeries/HvCallEvent.h>
+#include <asm/iSeries/ItLpNaca.h>
+
+/*
+ * The LpQueue is used to pass event data from the hypervisor to
+ * the partition.  This is where I/O interrupt events are communicated.
+ *
+ * It is written to by the hypervisor so cannot end up in the BSS.
+ */
+struct hvlpevent_queue hvlpevent_queue __attribute__((__section__(".data")));
+
+DEFINE_PER_CPU(unsigned long[HvLpEvent_Type_NumTypes], hvlpevent_counts);
+
+static char *event_types[HvLpEvent_Type_NumTypes] = {
+	"Hypervisor",
+	"Machine Facilities",
+	"Session Manager",
+	"SPD I/O",
+	"Virtual Bus",
+	"PCI I/O",
+	"RIO I/O",
+	"Virtual Lan",
+	"Virtual I/O"
+};
+
+/* Array of LpEvent handler functions */
+static LpEventHandler lpEventHandler[HvLpEvent_Type_NumTypes];
+static unsigned lpEventHandlerPaths[HvLpEvent_Type_NumTypes];
+
+static struct HvLpEvent * get_next_hvlpevent(void)
+{
+	struct HvLpEvent * event;
+	event = (struct HvLpEvent *)hvlpevent_queue.xSlicCurEventPtr;
+
+	if (event->xFlags.xValid) {
+		/* rmb() needed only for weakly consistent machines (regatta) */
+		rmb();
+		/* Set pointer to next potential event */
+		hvlpevent_queue.xSlicCurEventPtr += ((event->xSizeMinus1 +
+				LpEventAlign) / LpEventAlign) * LpEventAlign;
+
+		/* Wrap to beginning if no room at end */
+		if (hvlpevent_queue.xSlicCurEventPtr >
+				hvlpevent_queue.xSlicLastValidEventPtr) {
+			hvlpevent_queue.xSlicCurEventPtr =
+				hvlpevent_queue.xSlicEventStackPtr;
+		}
+	} else {
+		event = NULL;
+	}
+
+	return event;
+}
+
+static unsigned long spread_lpevents = NR_CPUS;
+
+int hvlpevent_is_pending(void)
+{
+	struct HvLpEvent *next_event;
+
+	if (smp_processor_id() >= spread_lpevents)
+		return 0;
+
+	next_event = (struct HvLpEvent *)hvlpevent_queue.xSlicCurEventPtr;
+
+	return next_event->xFlags.xValid |
+		hvlpevent_queue.xPlicOverflowIntPending;
+}
+
+static void hvlpevent_clear_valid(struct HvLpEvent * event)
+{
+	/* Tell the Hypervisor that we're done with this event.
+	 * Also clear bits within this event that might look like valid bits.
+	 * ie. on 64-byte boundaries.
+	 */
+	struct HvLpEvent *tmp;
+	unsigned extra = ((event->xSizeMinus1 + LpEventAlign) /
+						 LpEventAlign) - 1;
+
+	switch (extra) {
+	case 3:
+		tmp = (struct HvLpEvent*)((char*)event + 3 * LpEventAlign);
+		tmp->xFlags.xValid = 0;
+	case 2:
+		tmp = (struct HvLpEvent*)((char*)event + 2 * LpEventAlign);
+		tmp->xFlags.xValid = 0;
+	case 1:
+		tmp = (struct HvLpEvent*)((char*)event + 1 * LpEventAlign);
+		tmp->xFlags.xValid = 0;
+	}
+
+	mb();
+
+	event->xFlags.xValid = 0;
+}
+
+void process_hvlpevents(struct pt_regs *regs)
+{
+	struct HvLpEvent * event;
+
+	/* If we have recursed, just return */
+	if (!spin_trylock(&hvlpevent_queue.lock))
+		return;
+
+	for (;;) {
+		event = get_next_hvlpevent();
+		if (event) {
+			/* Call appropriate handler here, passing
+			 * a pointer to the LpEvent.  The handler
+			 * must make a copy of the LpEvent if it
+			 * needs it in a bottom half. (perhaps for
+			 * an ACK)
+			 *
+			 *  Handlers are responsible for ACK processing
+			 *
+			 * The Hypervisor guarantees that LpEvents will
+			 * only be delivered with types that we have
+			 * registered for, so no type check is necessary
+			 * here!
+			 */
+			if (event->xType < HvLpEvent_Type_NumTypes)
+				__get_cpu_var(hvlpevent_counts)[event->xType]++;
+			if (event->xType < HvLpEvent_Type_NumTypes &&
+					lpEventHandler[event->xType])
+				lpEventHandler[event->xType](event, regs);
+			else
+				printk(KERN_INFO "Unexpected Lp Event type=%d\n", event->xType );
+
+			hvlpevent_clear_valid(event);
+		} else if (hvlpevent_queue.xPlicOverflowIntPending)
+			/*
+			 * No more valid events. If overflow events are
+			 * pending process them
+			 */
+			HvCallEvent_getOverflowLpEvents(hvlpevent_queue.xIndex);
+		else
+			break;
+	}
+
+	spin_unlock(&hvlpevent_queue.lock);
+}
+
+static int set_spread_lpevents(char *str)
+{
+	unsigned long val = simple_strtoul(str, NULL, 0);
+
+	/*
+	 * The parameter is the number of processors to share in processing
+	 * lp events.
+	 */
+	if (( val > 0) && (val <= NR_CPUS)) {
+		spread_lpevents = val;
+		printk("lpevent processing spread over %ld processors\n", val);
+	} else {
+		printk("invalid spread_lpevents %ld\n", val);
+	}
+
+	return 1;
+}
+__setup("spread_lpevents=", set_spread_lpevents);
+
+void setup_hvlpevent_queue(void)
+{
+	void *eventStack;
+
+	/*
+	 * Allocate a page for the Event Stack. The Hypervisor needs the
+	 * absolute real address, so we subtract out the KERNELBASE and add
+	 * in the absolute real address of the kernel load area.
+	 */
+	eventStack = alloc_bootmem_pages(LpEventStackSize);
+	memset(eventStack, 0, LpEventStackSize);
+
+	/* Invoke the hypervisor to initialize the event stack */
+	HvCallEvent_setLpEventStack(0, eventStack, LpEventStackSize);
+
+	hvlpevent_queue.xSlicEventStackPtr = (char *)eventStack;
+	hvlpevent_queue.xSlicCurEventPtr = (char *)eventStack;
+	hvlpevent_queue.xSlicLastValidEventPtr = (char *)eventStack +
+					(LpEventStackSize - LpEventMaxSize);
+	hvlpevent_queue.xIndex = 0;
+}
+
+/* Register a handler for an LpEvent type */
+int HvLpEvent_registerHandler(HvLpEvent_Type eventType, LpEventHandler handler)
+{
+	if (eventType < HvLpEvent_Type_NumTypes) {
+		lpEventHandler[eventType] = handler;
+		return 0;
+	}
+	return 1;
+}
+EXPORT_SYMBOL(HvLpEvent_registerHandler);
+
+int HvLpEvent_unregisterHandler(HvLpEvent_Type eventType)
+{
+	might_sleep();
+
+	if (eventType < HvLpEvent_Type_NumTypes) {
+		if (!lpEventHandlerPaths[eventType]) {
+			lpEventHandler[eventType] = NULL;
+			/*
+			 * We now sleep until all other CPUs have scheduled.
+			 * This ensures that the deletion is seen by all
+			 * other CPUs, and that the deleted handler isn't
+			 * still running on another CPU when we return.
+			 */
+			synchronize_rcu();
+			return 0;
+		}
+	}
+	return 1;
+}
+EXPORT_SYMBOL(HvLpEvent_unregisterHandler);
+
+/*
+ * lpIndex is the partition index of the target partition.
+ * needed only for VirtualIo, VirtualLan and SessionMgr.  Zero
+ * indicates to use our partition index - for the other types.
+ */
+int HvLpEvent_openPath(HvLpEvent_Type eventType, HvLpIndex lpIndex)
+{
+	if ((eventType < HvLpEvent_Type_NumTypes) &&
+			lpEventHandler[eventType]) {
+		if (lpIndex == 0)
+			lpIndex = itLpNaca.xLpIndex;
+		HvCallEvent_openLpEventPath(lpIndex, eventType);
+		++lpEventHandlerPaths[eventType];
+		return 0;
+	}
+	return 1;
+}
+
+int HvLpEvent_closePath(HvLpEvent_Type eventType, HvLpIndex lpIndex)
+{
+	if ((eventType < HvLpEvent_Type_NumTypes) &&
+			lpEventHandler[eventType] &&
+			lpEventHandlerPaths[eventType]) {
+		if (lpIndex == 0)
+			lpIndex = itLpNaca.xLpIndex;
+		HvCallEvent_closeLpEventPath(lpIndex, eventType);
+		--lpEventHandlerPaths[eventType];
+		return 0;
+	}
+	return 1;
+}
+
+static int proc_lpevents_show(struct seq_file *m, void *v)
+{
+	int cpu, i;
+	unsigned long sum;
+	static unsigned long cpu_totals[NR_CPUS];
+
+	/* FIXME: do we care that there's no locking here? */
+	sum = 0;
+	for_each_online_cpu(cpu) {
+		cpu_totals[cpu] = 0;
+		for (i = 0; i < HvLpEvent_Type_NumTypes; i++) {
+			cpu_totals[cpu] += per_cpu(hvlpevent_counts, cpu)[i];
+		}
+		sum += cpu_totals[cpu];
+	}
+
+	seq_printf(m, "LpEventQueue 0\n");
+	seq_printf(m, "  events processed:\t%lu\n", sum);
+
+	for (i = 0; i < HvLpEvent_Type_NumTypes; ++i) {
+		sum = 0;
+		for_each_online_cpu(cpu) {
+			sum += per_cpu(hvlpevent_counts, cpu)[i];
+		}
+
+		seq_printf(m, "    %-20s %10lu\n", event_types[i], sum);
+	}
+
+	seq_printf(m, "\n  events processed by processor:\n");
+
+	for_each_online_cpu(cpu) {
+		seq_printf(m, "    CPU%02d  %10lu\n", cpu, cpu_totals[cpu]);
+	}
+
+	return 0;
+}
+
+static int proc_lpevents_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, proc_lpevents_show, NULL);
+}
+
+static struct file_operations proc_lpevents_operations = {
+	.open		= proc_lpevents_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int __init proc_lpevents_init(void)
+{
+	struct proc_dir_entry *e;
+
+	e = create_proc_entry("iSeries/lpevents", S_IFREG|S_IRUGO, NULL);
+	if (e)
+		e->proc_fops = &proc_lpevents_operations;
+
+	return 0;
+}
+__initcall(proc_lpevents_init);
+