1 files changed, 195 insertions, 99 deletions

diff --git a/arch/ppc64/kernel/ItLpQueue.c b/arch/ppc64/kernel/ItLpQueue.c
index cdea00d7707f..4231861288a3 100644
--- a/arch/ppc64/kernel/ItLpQueue.c
+++ b/arch/ppc64/kernel/ItLpQueue.c
@@ -1,7 +1,7 @@
 /*
  * ItLpQueue.c
  * 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
@@ -11,156 +11,252 @@
 #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 <asm/system.h>
 #include <asm/paca.h>
 #include <asm/iSeries/ItLpQueue.h>
 #include <asm/iSeries/HvLpEvent.h>
 #include <asm/iSeries/HvCallEvent.h>
 
-static __inline__ int set_inUse( struct ItLpQueue * lpQueue )
-{
-        int t;
-        u32 * inUseP = &(lpQueue->xInUseWord);
-
-        __asm__ __volatile__("\n\
-1:      lwarx   %0,0,%2         \n\
-        cmpwi   0,%0,0          \n\
-        li      %0,0            \n\
-        bne-    2f              \n\
-        addi    %0,%0,1         \n\
-        stwcx.  %0,0,%2         \n\
-        bne-    1b              \n\
-2:      eieio"
-        : "=&r" (t), "=m" (lpQueue->xInUseWord)
-        : "r" (inUseP), "m" (lpQueue->xInUseWord)
-        : "cc");
-
-        return t;
-}
+/*
+ * 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")));
 
-static __inline__ void clear_inUse( struct ItLpQueue * lpQueue )
-{
-        lpQueue->xInUseWord = 0;
-}
+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 */
 extern LpEventHandler lpEventHandler[HvLpEvent_Type_NumTypes];
-unsigned long ItLpQueueInProcess = 0;
 
-struct HvLpEvent * ItLpQueue_getNextLpEvent( struct ItLpQueue * lpQueue )
+static struct HvLpEvent * get_next_hvlpevent(void)
 {
-        struct HvLpEvent * nextLpEvent = 
-                (struct HvLpEvent *)lpQueue->xSlicCurEventPtr;
-        if ( nextLpEvent->xFlags.xValid ) {
+        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 */
-                lpQueue->xSlicCurEventPtr += ((nextLpEvent->xSizeMinus1 +
-                                      LpEventAlign ) /
-                                      LpEventAlign ) *
-                                      LpEventAlign;
+                hvlpevent_queue.xSlicCurEventPtr += ((event->xSizeMinus1 +
+                                LpEventAlign) / LpEventAlign) * LpEventAlign;
+
                 /* Wrap to beginning if no room at end */
-                if (lpQueue->xSlicCurEventPtr > lpQueue->xSlicLastValidEventPtr)
-                        lpQueue->xSlicCurEventPtr = lpQueue->xSlicEventStackPtr;
+                if (hvlpevent_queue.xSlicCurEventPtr >
+                                hvlpevent_queue.xSlicLastValidEventPtr) {
+                        hvlpevent_queue.xSlicCurEventPtr =
+                                hvlpevent_queue.xSlicEventStackPtr;
+                }
+        } else {
+                event = NULL;
         }
-        else 
-                nextLpEvent = NULL;
 
-        return nextLpEvent;
+        return event;
 }
 
-int ItLpQueue_isLpIntPending( struct ItLpQueue * lpQueue )
+static unsigned long spread_lpevents = NR_CPUS;
+
+int hvlpevent_is_pending(void)
 {
-        int retval = 0;
-        struct HvLpEvent * nextLpEvent;
-        if ( lpQueue ) {
-                nextLpEvent = (struct HvLpEvent *)lpQueue->xSlicCurEventPtr;
-                retval = nextLpEvent->xFlags.xValid | lpQueue->xPlicOverflowIntPending;
-        }
-        return retval;
+        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;
 }
 
-void ItLpQueue_clearValid( struct HvLpEvent * event )
+static void hvlpevent_clear_valid(struct HvLpEvent * event)
 {
-        /* Clear the valid bit of the event
-         * Also clear bits within this event that might
-         * look like valid bits (on 64-byte boundaries)
-         */
-        unsigned extra = (( event->xSizeMinus1 + LpEventAlign ) /
-                                                 LpEventAlign ) - 1;
-        switch ( extra ) {
-          case 3:
-           ((struct HvLpEvent*)((char*)event+3*LpEventAlign))->xFlags.xValid=0;
-          case 2:
-           ((struct HvLpEvent*)((char*)event+2*LpEventAlign))->xFlags.xValid=0;
-          case 1:
-           ((struct HvLpEvent*)((char*)event+1*LpEventAlign))->xFlags.xValid=0;
-          case 0:
-           ;    
+        /* 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;
 }
 
-unsigned ItLpQueue_process( struct ItLpQueue * lpQueue, struct pt_regs *regs )
+void process_hvlpevents(struct pt_regs *regs)
 {
-        unsigned numIntsProcessed = 0;
-        struct HvLpEvent * nextLpEvent;
+        struct HvLpEvent * event;
 
         /* If we have recursed, just return */
-        if ( !set_inUse( lpQueue ) )
-                return 0;
-        
-        if (ItLpQueueInProcess == 0)
-                ItLpQueueInProcess = 1;
-        else
-                BUG();
+        if (!spin_trylock(&hvlpevent_queue.lock))
+                return;
 
         for (;;) {
-                nextLpEvent = ItLpQueue_getNextLpEvent( lpQueue );
-                if ( nextLpEvent ) {
-                        /* Count events to return to caller
-                         * and count processed events in lpQueue
-                         */
-                        ++numIntsProcessed;
-                        lpQueue->xLpIntCount++;         
-                        /* Call appropriate handler here, passing 
+                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 
+                         *
+                         *  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 ( nextLpEvent->xType < HvLpEvent_Type_NumTypes )
-                                lpQueue->xLpIntCountByType[nextLpEvent->xType]++;
-                        if ( nextLpEvent->xType < HvLpEvent_Type_NumTypes &&
-                             lpEventHandler[nextLpEvent->xType] ) 
-                                lpEventHandler[nextLpEvent->xType](nextLpEvent, regs);
+                         */
+                        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", nextLpEvent->xType );
-                        
-                        ItLpQueue_clearValid( nextLpEvent );
-                } else if ( lpQueue->xPlicOverflowIntPending )
+                                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( lpQueue->xIndex);
+                        HvCallEvent_getOverflowLpEvents(hvlpevent_queue.xIndex);
                 else
                         break;
         }
 
-        ItLpQueueInProcess = 0;
-        mb();
-        clear_inUse( lpQueue );
+        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);
+        }
 
-        get_paca()->lpevent_count += numIntsProcessed;
+        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;
+}
+
+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);
+}
 
-        return numIntsProcessed;
+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);
+