release/src-rt-6.x.4708/linux/linux-2.6.36/arch/powerpc/platforms/85xx/smp.c

   1 /*
   2  * Author: Andy Fleming <afleming@freescale.com>
   3  *         Kumar Gala <galak@kernel.crashing.org>
   4  *
   5  * Copyright 2006-2008 Freescale Semiconductor Inc.
   6  *
   7  * This program is free software; you can redistribute  it and/or modify it
   8  * under  the terms of  the GNU General  Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  */
  12
  13 #include <linux/stddef.h>
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/delay.h>
  17 #include <linux/of.h>
  18 #include <linux/kexec.h>
  19
  20 #include <asm/machdep.h>
  21 #include <asm/pgtable.h>
  22 #include <asm/page.h>
  23 #include <asm/mpic.h>
  24 #include <asm/cacheflush.h>
  25 #include <asm/dbell.h>
  26
  27 #include <sysdev/fsl_soc.h>
  28 #include <sysdev/mpic.h>
  29
  30 extern void __early_start(void);
  31
  32 #define BOOT_ENTRY_ADDR_UPPER   0
  33 #define BOOT_ENTRY_ADDR_LOWER   1
  34 #define BOOT_ENTRY_R3_UPPER     2
  35 #define BOOT_ENTRY_R3_LOWER     3
  36 #define BOOT_ENTRY_RESV         4
  37 #define BOOT_ENTRY_PIR          5
  38 #define BOOT_ENTRY_R6_UPPER     6
  39 #define BOOT_ENTRY_R6_LOWER     7
  40 #define NUM_BOOT_ENTRY          8
  41 #define SIZE_BOOT_ENTRY         (NUM_BOOT_ENTRY * sizeof(u32))
  42
  43 static void __init
  44 smp_85xx_kick_cpu(int nr)
  45 {
  46         unsigned long flags;
  47         const u64 *cpu_rel_addr;
  48         __iomem u32 *bptr_vaddr;
  49         struct device_node *np;
  50         int n = 0;
  51         int ioremappable;
  52
  53         WARN_ON (nr < 0 || nr >= NR_CPUS);
  54
  55         pr_debug("smp_85xx_kick_cpu: kick CPU #%d\n", nr);
  56
  57         np = of_get_cpu_node(nr, NULL);
  58         cpu_rel_addr = of_get_property(np, "cpu-release-addr", NULL);
  59
  60         if (cpu_rel_addr == NULL) {
  61                 printk(KERN_ERR "No cpu-release-addr for cpu %d\n", nr);
  62                 return;
  63         }
  64
  65         /*
  66          * A secondary core could be in a spinloop in the bootpage
  67          * (0xfffff000), somewhere in highmem, or somewhere in lowmem.
  68          * The bootpage and highmem can be accessed via ioremap(), but
  69          * we need to directly access the spinloop if its in lowmem.
  70          */
  71         ioremappable = *cpu_rel_addr > virt_to_phys(high_memory);
  72
  73         /* Map the spin table */
  74         if (ioremappable)
  75                 bptr_vaddr = ioremap(*cpu_rel_addr, SIZE_BOOT_ENTRY);
  76         else
  77                 bptr_vaddr = phys_to_virt(*cpu_rel_addr);
  78
  79         local_irq_save(flags);
  80
  81         out_be32(bptr_vaddr + BOOT_ENTRY_PIR, nr);
  82         out_be32(bptr_vaddr + BOOT_ENTRY_ADDR_LOWER, __pa(__early_start));
  83
  84         if (!ioremappable)
  85                 flush_dcache_range((ulong)bptr_vaddr,
  86                                 (ulong)(bptr_vaddr + SIZE_BOOT_ENTRY));
  87
  88         /* Wait a bit for the CPU to ack. */
  89         while ((__secondary_hold_acknowledge != nr) && (++n < 1000))
  90                 mdelay(1);
  91
  92         local_irq_restore(flags);
  93
  94         if (ioremappable)
  95                 iounmap(bptr_vaddr);
  96
  97         pr_debug("waited %d msecs for CPU #%d.\n", n, nr);
  98 }
  99
 100 static void __init
 101 smp_85xx_setup_cpu(int cpu_nr)
 102 {
 103         mpic_setup_this_cpu();
 104         if (cpu_has_feature(CPU_FTR_DBELL))
 105                 doorbell_setup_this_cpu();
 106 }
 107
 108 struct smp_ops_t smp_85xx_ops = {
 109         .kick_cpu = smp_85xx_kick_cpu,
 110 #ifdef CONFIG_KEXEC
 111         .give_timebase  = smp_generic_give_timebase,
 112         .take_timebase  = smp_generic_take_timebase,
 113 #endif
 114 };
 115
 116 #ifdef CONFIG_KEXEC
 117 static int kexec_down_cpus = 0;
 118
 119 void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
 120 {
 121         mpic_teardown_this_cpu(1);
 122
 123         /* When crashing, this gets called on all CPU's we only
 124          * take down the non-boot cpus */
 125         if (smp_processor_id() != boot_cpuid)
 126         {
 127                 local_irq_disable();
 128                 kexec_down_cpus++;
 129
 130                 while (1);
 131         }
 132 }
 133
 134 static void mpc85xx_smp_kexec_down(void *arg)
 135 {
 136         if (ppc_md.kexec_cpu_down)
 137                 ppc_md.kexec_cpu_down(0,1);
 138 }
 139
 140 static void mpc85xx_smp_machine_kexec(struct kimage *image)
 141 {
 142         int timeout = 2000;
 143         int i;
 144
 145         set_cpus_allowed(current, cpumask_of_cpu(boot_cpuid));
 146
 147         smp_call_function(mpc85xx_smp_kexec_down, NULL, 0);
 148
 149         while ( (kexec_down_cpus != (num_online_cpus() - 1)) &&
 150                 ( timeout > 0 ) )
 151         {
 152                 timeout--;
 153         }
 154
 155         if ( !timeout )
 156                 printk(KERN_ERR "Unable to bring down secondary cpu(s)");
 157
 158         for (i = 0; i < num_present_cpus(); i++)
 159         {
 160                 if ( i == smp_processor_id() ) continue;
 161                 mpic_reset_core(i);
 162         }
 163
 164         default_machine_kexec(image);
 165 }
 166 #endif /* CONFIG_KEXEC */
 167
 168 void __init mpc85xx_smp_init(void)
 169 {
 170         struct device_node *np;
 171
 172         np = of_find_node_by_type(NULL, "open-pic");
 173         if (np) {
 174                 smp_85xx_ops.probe = smp_mpic_probe;
 175                 smp_85xx_ops.setup_cpu = smp_85xx_setup_cpu;
 176                 smp_85xx_ops.message_pass = smp_mpic_message_pass;
 177         }
 178
 179         if (cpu_has_feature(CPU_FTR_DBELL))
 180                 smp_85xx_ops.message_pass = doorbell_message_pass;
 181
 182         BUG_ON(!smp_85xx_ops.message_pass);
 183
 184         smp_ops = &smp_85xx_ops;
 185
 186 #ifdef CONFIG_KEXEC
 187         ppc_md.kexec_cpu_down = mpc85xx_smp_kexec_cpu_down;
 188         ppc_md.machine_kexec = mpc85xx_smp_machine_kexec;
 189 #endif
 190 }