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/LparData.h>
  42 #include <asm/iSeries/HvCall.h>
  43 #include <asm/iSeries/HvCallCfg.h>
  44 #include <asm/time.h>
  45 #include <asm/ppcdebug.h>
  46 #include <asm/machdep.h>
  47 #include <asm/cputable.h>
  48 #include <asm/system.h>
  49
  50 static unsigned long iSeries_smp_message[NR_CPUS];
  51
  52 void iSeries_smp_message_recv( struct pt_regs * regs )
  53 {
  54         int cpu = smp_processor_id();
  55         int msg;
  56
  57         if ( num_online_cpus() < 2 )
  58                 return;
  59
  60         for ( msg = 0; msg < 4; ++msg )
  61                 if ( test_and_clear_bit( msg, &iSeries_smp_message[cpu] ) )
  62                         smp_message_recv( msg, regs );
  63 }
  64
  65 static inline void smp_iSeries_do_message(int cpu, int msg)
  66 {
  67         set_bit(msg, &iSeries_smp_message[cpu]);
  68         HvCall_sendIPI(&(paca[cpu]));
  69 }
  70
  71 static void smp_iSeries_message_pass(int target, int msg)
  72 {
  73         int i;
  74
  75         if (target < NR_CPUS)
  76                 smp_iSeries_do_message(target, msg);
  77         else {
  78                 for_each_online_cpu(i) {
  79                         if (target == MSG_ALL_BUT_SELF
  80                             && i == smp_processor_id())
  81                                 continue;
  82                         smp_iSeries_do_message(i, msg);
  83                 }
  84         }
  85 }
  86
  87 static int smp_iSeries_numProcs(void)
  88 {
  89         unsigned np, i;
  90
  91         np = 0;
  92         for (i=0; i < NR_CPUS; ++i) {
  93                 if (paca[i].lppaca.dyn_proc_status < 2) {
  94                         cpu_set(i, cpu_possible_map);
  95                         cpu_set(i, cpu_present_map);
  96                         cpu_set(i, cpu_sibling_map[i]);
  97                         ++np;
  98                 }
  99         }
 100         return np;
 101 }
 102
 103 static int smp_iSeries_probe(void)
 104 {
 105         unsigned i;
 106         unsigned np = 0;
 107
 108         for (i=0; i < NR_CPUS; ++i) {
 109                 if (paca[i].lppaca.dyn_proc_status < 2) {
 110                         /*paca[i].active = 1;*/
 111                         ++np;
 112                 }
 113         }
 114
 115         return np;
 116 }
 117
 118 static void smp_iSeries_kick_cpu(int nr)
 119 {
 120         BUG_ON(nr < 0 || nr >= NR_CPUS);
 121
 122         /* Verify that our partition has a processor nr */
 123         if (paca[nr].lppaca.dyn_proc_status >= 2)
 124                 return;
 125
 126         /* The processor is currently spinning, waiting
 127          * for the cpu_start field to become non-zero
 128          * After we set cpu_start, the processor will
 129          * continue on to secondary_start in iSeries_head.S
 130          */
 131         paca[nr].cpu_start = 1;
 132 }
 133
 134 static void __devinit smp_iSeries_setup_cpu(int nr)
 135 {
 136 }
 137
 138 static struct smp_ops_t iSeries_smp_ops = {
 139         .message_pass = smp_iSeries_message_pass,
 140         .probe        = smp_iSeries_probe,
 141         .kick_cpu     = smp_iSeries_kick_cpu,
 142         .setup_cpu    = smp_iSeries_setup_cpu,
 143 };
 144
 145 /* This is called very early. */
 146 void __init smp_init_iSeries(void)
 147 {
 148         smp_ops = &iSeries_smp_ops;
 149         systemcfg->processorCount       = smp_iSeries_numProcs();
 150 }
 151