arch/ppc64/kernel/ItLpQueue.c

   1 /*
   2  * ItLpQueue.c
   3  * Copyright (C) 2001 Mike Corrigan  IBM Corporation
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  */
  10
  11 #include <linux/stddef.h>
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/proc_fs.h>
  17 #include <asm/system.h>
  18 #include <asm/paca.h>
  19 #include <asm/iSeries/ItLpQueue.h>
  20 #include <asm/iSeries/HvLpEvent.h>
  21 #include <asm/iSeries/HvCallEvent.h>
  22
  23 /*
  24  * The LpQueue is used to pass event data from the hypervisor to
  25  * the partition.  This is where I/O interrupt events are communicated.
  26  *
  27  * It is written to by the hypervisor so cannot end up in the BSS.
  28  */
  29 struct hvlpevent_queue hvlpevent_queue __attribute__((__section__(".data")));
  30
  31 DEFINE_PER_CPU(unsigned long[HvLpEvent_Type_NumTypes], hvlpevent_counts);
  32
  33 static char *event_types[HvLpEvent_Type_NumTypes] = {
  34         "Hypervisor",
  35         "Machine Facilities",
  36         "Session Manager",
  37         "SPD I/O",
  38         "Virtual Bus",
  39         "PCI I/O",
  40         "RIO I/O",
  41         "Virtual Lan",
  42         "Virtual I/O"
  43 };
  44
  45 /* Array of LpEvent handler functions */
  46 extern LpEventHandler lpEventHandler[HvLpEvent_Type_NumTypes];
  47
  48 static struct HvLpEvent * get_next_hvlpevent(void)
  49 {
  50         struct HvLpEvent * event;
  51         event = (struct HvLpEvent *)hvlpevent_queue.xSlicCurEventPtr;
  52
  53         if (event->xFlags.xValid) {
  54                 /* rmb() needed only for weakly consistent machines (regatta) */
  55                 rmb();
  56                 /* Set pointer to next potential event */
  57                 hvlpevent_queue.xSlicCurEventPtr += ((event->xSizeMinus1 +
  58                                 LpEventAlign) / LpEventAlign) * LpEventAlign;
  59
  60                 /* Wrap to beginning if no room at end */
  61                 if (hvlpevent_queue.xSlicCurEventPtr >
  62                                 hvlpevent_queue.xSlicLastValidEventPtr) {
  63                         hvlpevent_queue.xSlicCurEventPtr =
  64                                 hvlpevent_queue.xSlicEventStackPtr;
  65                 }
  66         } else {
  67                 event = NULL;
  68         }
  69
  70         return event;
  71 }
  72
  73 static unsigned long spread_lpevents = NR_CPUS;
  74
  75 int hvlpevent_is_pending(void)
  76 {
  77         struct HvLpEvent *next_event;
  78
  79         if (smp_processor_id() >= spread_lpevents)
  80                 return 0;
  81
  82         next_event = (struct HvLpEvent *)hvlpevent_queue.xSlicCurEventPtr;
  83
  84         return next_event->xFlags.xValid |
  85                 hvlpevent_queue.xPlicOverflowIntPending;
  86 }
  87
  88 static void hvlpevent_clear_valid(struct HvLpEvent * event)
  89 {
  90         /* Tell the Hypervisor that we're done with this event.
  91          * Also clear bits within this event that might look like valid bits.
  92          * ie. on 64-byte boundaries.
  93          */
  94         struct HvLpEvent *tmp;
  95         unsigned extra = ((event->xSizeMinus1 + LpEventAlign) /
  96                                                  LpEventAlign) - 1;
  97
  98         switch (extra) {
  99         case 3:
 100                 tmp = (struct HvLpEvent*)((char*)event + 3 * LpEventAlign);
 101                 tmp->xFlags.xValid = 0;
 102         case 2:
 103                 tmp = (struct HvLpEvent*)((char*)event + 2 * LpEventAlign);
 104                 tmp->xFlags.xValid = 0;
 105         case 1:
 106                 tmp = (struct HvLpEvent*)((char*)event + 1 * LpEventAlign);
 107                 tmp->xFlags.xValid = 0;
 108         }
 109
 110         mb();
 111
 112         event->xFlags.xValid = 0;
 113 }
 114
 115 void process_hvlpevents(struct pt_regs *regs)
 116 {
 117         struct HvLpEvent * event;
 118
 119         /* If we have recursed, just return */
 120         if (!spin_trylock(&hvlpevent_queue.lock))
 121                 return;
 122
 123         for (;;) {
 124                 event = get_next_hvlpevent();
 125                 if (event) {
 126                         /* Call appropriate handler here, passing
 127                          * a pointer to the LpEvent.  The handler
 128                          * must make a copy of the LpEvent if it
 129                          * needs it in a bottom half. (perhaps for
 130                          * an ACK)
 131                          *
 132                          *  Handlers are responsible for ACK processing
 133                          *
 134                          * The Hypervisor guarantees that LpEvents will
 135                          * only be delivered with types that we have
 136                          * registered for, so no type check is necessary
 137                          * here!
 138                          */
 139                         if (event->xType < HvLpEvent_Type_NumTypes)
 140                                 __get_cpu_var(hvlpevent_counts)[event->xType]++;
 141                         if (event->xType < HvLpEvent_Type_NumTypes &&
 142                                         lpEventHandler[event->xType])
 143                                 lpEventHandler[event->xType](event, regs);
 144                         else
 145                                 printk(KERN_INFO "Unexpected Lp Event type=%d\n", event->xType );
 146
 147                         hvlpevent_clear_valid(event);
 148                 } else if (hvlpevent_queue.xPlicOverflowIntPending)
 149                         /*
 150                          * No more valid events. If overflow events are
 151                          * pending process them
 152                          */
 153                         HvCallEvent_getOverflowLpEvents(hvlpevent_queue.xIndex);
 154                 else
 155                         break;
 156         }
 157
 158         spin_unlock(&hvlpevent_queue.lock);
 159 }
 160
 161 static int set_spread_lpevents(char *str)
 162 {
 163         unsigned long val = simple_strtoul(str, NULL, 0);
 164
 165         /*
 166          * The parameter is the number of processors to share in processing
 167          * lp events.
 168          */
 169         if (( val > 0) && (val <= NR_CPUS)) {
 170                 spread_lpevents = val;
 171                 printk("lpevent processing spread over %ld processors\n", val);
 172         } else {
 173                 printk("invalid spread_lpevents %ld\n", val);
 174         }
 175
 176         return 1;
 177 }
 178 __setup("spread_lpevents=", set_spread_lpevents);
 179
 180 void setup_hvlpevent_queue(void)
 181 {
 182         void *eventStack;
 183
 184         /*
 185          * Allocate a page for the Event Stack. The Hypervisor needs the
 186          * absolute real address, so we subtract out the KERNELBASE and add
 187          * in the absolute real address of the kernel load area.
 188          */
 189         eventStack = alloc_bootmem_pages(LpEventStackSize);
 190         memset(eventStack, 0, LpEventStackSize);
 191
 192         /* Invoke the hypervisor to initialize the event stack */
 193         HvCallEvent_setLpEventStack(0, eventStack, LpEventStackSize);
 194
 195         hvlpevent_queue.xSlicEventStackPtr = (char *)eventStack;
 196         hvlpevent_queue.xSlicCurEventPtr = (char *)eventStack;
 197         hvlpevent_queue.xSlicLastValidEventPtr = (char *)eventStack +
 198                                         (LpEventStackSize - LpEventMaxSize);
 199         hvlpevent_queue.xIndex = 0;
 200 }
 201
 202 static int proc_lpevents_show(struct seq_file *m, void *v)
 203 {
 204         int cpu, i;
 205         unsigned long sum;
 206         static unsigned long cpu_totals[NR_CPUS];
 207
 208         /* FIXME: do we care that there's no locking here? */
 209         sum = 0;
 210         for_each_online_cpu(cpu) {
 211                 cpu_totals[cpu] = 0;
 212                 for (i = 0; i < HvLpEvent_Type_NumTypes; i++) {
 213                         cpu_totals[cpu] += per_cpu(hvlpevent_counts, cpu)[i];
 214                 }
 215                 sum += cpu_totals[cpu];
 216         }
 217
 218         seq_printf(m, "LpEventQueue 0\n");
 219         seq_printf(m, "  events processed:\t%lu\n", sum);
 220
 221         for (i = 0; i < HvLpEvent_Type_NumTypes; ++i) {
 222                 sum = 0;
 223                 for_each_online_cpu(cpu) {
 224                         sum += per_cpu(hvlpevent_counts, cpu)[i];
 225                 }
 226
 227                 seq_printf(m, "    %-20s %10lu\n", event_types[i], sum);
 228         }
 229
 230         seq_printf(m, "\n  events processed by processor:\n");
 231
 232         for_each_online_cpu(cpu) {
 233                 seq_printf(m, "    CPU%02d  %10lu\n", cpu, cpu_totals[cpu]);
 234         }
 235
 236         return 0;
 237 }
 238
 239 static int proc_lpevents_open(struct inode *inode, struct file *file)
 240 {
 241         return single_open(file, proc_lpevents_show, NULL);
 242 }
 243
 244 static struct file_operations proc_lpevents_operations = {
 245         .open           = proc_lpevents_open,
 246         .read           = seq_read,
 247         .llseek         = seq_lseek,
 248         .release        = single_release,
 249 };
 250
 251 static int __init proc_lpevents_init(void)
 252 {
 253         struct proc_dir_entry *e;
 254
 255         e = create_proc_entry("iSeries/lpevents", S_IFREG|S_IRUGO, NULL);
 256         if (e)
 257                 e->proc_fops = &proc_lpevents_operations;
 258
 259         return 0;
 260 }
 261 __initcall(proc_lpevents_init);
 262