arch/ppc64/kernel/iSeries_smp.c

   1 /*
   2  * SMP support for iSeries machines.
   3  *
   4  * Dave Engebretsen, Peter Bergner, and
   5  * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
   6  *
   7  * Plus various changes from other IBM teams...
   8  *
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License
  11  *      as published by the Free Software Foundation; either version
  12  *      2 of the License, or (at your option) any later version.
  13  */
  14
  15 #undef DEBUG
  16
  17 #include <linux/config.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/sched.h>
  21 #include <linux/smp.h>
  22 #include <linux/smp_lock.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/kernel_stat.h>
  25 #include <linux/delay.h>
  26 #include <linux/init.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/cache.h>
  29 #include <linux/err.h>
  30 #include <linux/sysdev.h>
  31 #include <linux/cpu.h>
  32
  33 #include <asm/ptrace.h>
  34 #include <asm/atomic.h>
  35 #include <asm/irq.h>
  36 #include <asm/page.h>
  37 #include <asm/pgtable.h>
  38 #include <asm/io.h>
  39 #include <asm/smp.h>
  40 #include <asm/paca.h>
  41 #include <asm/iSeries/HvCall.h>
  42 #include <asm/time.h>
  43 #include <asm/ppcdebug.h>
  44 #include <asm/machdep.h>
  45 #include <asm/cputable.h>
  46 #include <asm/system.h>
  47
  48 static unsigned long iSeries_smp_message[NR_CPUS];
  49
  50 void iSeries_smp_message_recv( struct pt_regs * regs )
  51 {
  52         int cpu = smp_processor_id();
  53         int msg;
  54
  55         if ( num_online_cpus() < 2 )
  56                 return;
  57
  58         for ( msg = 0; msg < 4; ++msg )
  59                 if ( test_and_clear_bit( msg, &iSeries_smp_message[cpu] ) )
  60                         smp_message_recv( msg, regs );
  61 }
  62
  63 static inline void smp_iSeries_do_message(int cpu, int msg)
  64 {
  65         set_bit(msg, &iSeries_smp_message[cpu]);
  66         HvCall_sendIPI(&(paca[cpu]));
  67 }
  68
  69 static void smp_iSeries_message_pass(int target, int msg)
  70 {
  71         int i;
  72
  73         if (target < NR_CPUS)
  74                 smp_iSeries_do_message(target, msg);
  75         else {
  76                 for_each_online_cpu(i) {
  77                         if (target == MSG_ALL_BUT_SELF
  78                             && i == smp_processor_id())
  79                                 continue;
  80                         smp_iSeries_do_message(i, msg);
  81                 }
  82         }
  83 }
  84
  85 static int smp_iSeries_numProcs(void)
  86 {
  87         unsigned np, i;
  88
  89         np = 0;
  90         for (i=0; i < NR_CPUS; ++i) {
  91                 if (paca[i].lppaca.dyn_proc_status < 2) {
  92                         cpu_set(i, cpu_possible_map);
  93                         cpu_set(i, cpu_present_map);
  94                         cpu_set(i, cpu_sibling_map[i]);
  95                         ++np;
  96                 }
  97         }
  98         return np;
  99 }
 100
 101 static int smp_iSeries_probe(void)
 102 {
 103         unsigned i;
 104         unsigned np = 0;
 105
 106         for (i=0; i < NR_CPUS; ++i) {
 107                 if (paca[i].lppaca.dyn_proc_status < 2) {
 108                         /*paca[i].active = 1;*/
 109                         ++np;
 110                 }
 111         }
 112
 113         return np;
 114 }
 115
 116 static void smp_iSeries_kick_cpu(int nr)
 117 {
 118         BUG_ON(nr < 0 || nr >= NR_CPUS);
 119
 120         /* Verify that our partition has a processor nr */
 121         if (paca[nr].lppaca.dyn_proc_status >= 2)
 122                 return;
 123
 124         /* The processor is currently spinning, waiting
 125          * for the cpu_start field to become non-zero
 126          * After we set cpu_start, the processor will
 127          * continue on to secondary_start in iSeries_head.S
 128          */
 129         paca[nr].cpu_start = 1;
 130 }
 131
 132 static void __devinit smp_iSeries_setup_cpu(int nr)
 133 {
 134 }
 135
 136 static struct smp_ops_t iSeries_smp_ops = {
 137         .message_pass = smp_iSeries_message_pass,
 138         .probe        = smp_iSeries_probe,
 139         .kick_cpu     = smp_iSeries_kick_cpu,
 140         .setup_cpu    = smp_iSeries_setup_cpu,
 141 };
 142
 143 /* This is called very early. */
 144 void __init smp_init_iSeries(void)
 145 {
 146         smp_ops = &iSeries_smp_ops;
 147         systemcfg->processorCount       = smp_iSeries_numProcs();
 148 }
 149