arch/powerpc/platforms/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/kernel.h>
  18 #include <linux/sched.h>
  19 #include <linux/smp.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/kernel_stat.h>
  22 #include <linux/delay.h>
  23 #include <linux/init.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/cache.h>
  26 #include <linux/err.h>
  27 #include <linux/device.h>
  28 #include <linux/cpu.h>
  29
  30 #include <asm/ptrace.h>
  31 #include <linux/atomic.h>
  32 #include <asm/irq.h>
  33 #include <asm/page.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/io.h>
  36 #include <asm/smp.h>
  37 #include <asm/paca.h>
  38 #include <asm/iseries/hv_call.h>
  39 #include <asm/time.h>
  40 #include <asm/machdep.h>
  41 #include <asm/cputable.h>
  42 #include <asm/system.h>
  43
  44 static void smp_iSeries_cause_ipi(int cpu, unsigned long data)
  45 {
  46         HvCall_sendIPI(&(paca[cpu]));
  47 }
  48
  49 static int smp_iSeries_probe(void)
  50 {
  51         return cpumask_weight(cpu_possible_mask);
  52 }
  53
  54 static int smp_iSeries_kick_cpu(int nr)
  55 {
  56         BUG_ON((nr < 0) || (nr >= NR_CPUS));
  57
  58         /* Verify that our partition has a processor nr */
  59         if (lppaca_of(nr).dyn_proc_status >= 2)
  60                 return -ENOENT;
  61
  62         /* The processor is currently spinning, waiting
  63          * for the cpu_start field to become non-zero
  64          * After we set cpu_start, the processor will
  65          * continue on to secondary_start in iSeries_head.S
  66          */
  67         paca[nr].cpu_start = 1;
  68
  69         return 0;
  70 }
  71
  72 static void __devinit smp_iSeries_setup_cpu(int nr)
  73 {
  74 }
  75
  76 static struct smp_ops_t iSeries_smp_ops = {
  77         .message_pass = NULL,   /* Use smp_muxed_ipi_message_pass */
  78         .cause_ipi    = smp_iSeries_cause_ipi,
  79         .probe        = smp_iSeries_probe,
  80         .kick_cpu     = smp_iSeries_kick_cpu,
  81         .setup_cpu    = smp_iSeries_setup_cpu,
  82 };
  83
  84 /* This is called very early. */
  85 void __init smp_init_iSeries(void)
  86 {
  87         smp_ops = &iSeries_smp_ops;
  88 }