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
  19 #include <asm/machdep.h>
  20 #include <asm/pgtable.h>
  21 #include <asm/page.h>
  22 #include <asm/mpic.h>
  23 #include <asm/cacheflush.h>
  24 #include <asm/dbell.h>
  25
  26 #include <sysdev/fsl_soc.h>
  27
  28 extern void __early_start(void);
  29
  30 #define BOOT_ENTRY_ADDR_UPPER   0
  31 #define BOOT_ENTRY_ADDR_LOWER   1
  32 #define BOOT_ENTRY_R3_UPPER     2
  33 #define BOOT_ENTRY_R3_LOWER     3
  34 #define BOOT_ENTRY_RESV         4
  35 #define BOOT_ENTRY_PIR          5
  36 #define BOOT_ENTRY_R6_UPPER     6
  37 #define BOOT_ENTRY_R6_LOWER     7
  38 #define NUM_BOOT_ENTRY          8
  39 #define SIZE_BOOT_ENTRY         (NUM_BOOT_ENTRY * sizeof(u32))
  40
  41 static void __init
  42 smp_85xx_kick_cpu(int nr)
  43 {
  44         unsigned long flags;
  45         const u64 *cpu_rel_addr;
  46         __iomem u32 *bptr_vaddr;
  47         struct device_node *np;
  48         int n = 0;
  49         int ioremappable;
  50
  51         WARN_ON (nr < 0 || nr >= NR_CPUS);
  52
  53         pr_debug("smp_85xx_kick_cpu: kick CPU #%d\n", nr);
  54
  55         np = of_get_cpu_node(nr, NULL);
  56         cpu_rel_addr = of_get_property(np, "cpu-release-addr", NULL);
  57
  58         if (cpu_rel_addr == NULL) {
  59                 printk(KERN_ERR "No cpu-release-addr for cpu %d\n", nr);
  60                 return;
  61         }
  62
  63         /*
  64          * A secondary core could be in a spinloop in the bootpage
  65          * (0xfffff000), somewhere in highmem, or somewhere in lowmem.
  66          * The bootpage and highmem can be accessed via ioremap(), but
  67          * we need to directly access the spinloop if its in lowmem.
  68          */
  69         ioremappable = *cpu_rel_addr > virt_to_phys(high_memory);
  70
  71         /* Map the spin table */
  72         if (ioremappable)
  73                 bptr_vaddr = ioremap(*cpu_rel_addr, SIZE_BOOT_ENTRY);
  74         else
  75                 bptr_vaddr = phys_to_virt(*cpu_rel_addr);
  76
  77         local_irq_save(flags);
  78
  79         out_be32(bptr_vaddr + BOOT_ENTRY_PIR, nr);
  80         out_be32(bptr_vaddr + BOOT_ENTRY_ADDR_LOWER, __pa(__early_start));
  81
  82         if (!ioremappable)
  83                 flush_dcache_range((ulong)bptr_vaddr,
  84                                 (ulong)(bptr_vaddr + SIZE_BOOT_ENTRY));
  85
  86         /* Wait a bit for the CPU to ack. */
  87         while ((__secondary_hold_acknowledge != nr) && (++n < 1000))
  88                 mdelay(1);
  89
  90         local_irq_restore(flags);
  91
  92         if (ioremappable)
  93                 iounmap(bptr_vaddr);
  94
  95         pr_debug("waited %d msecs for CPU #%d.\n", n, nr);
  96 }
  97
  98 static void __init
  99 smp_85xx_setup_cpu(int cpu_nr)
 100 {
 101         mpic_setup_this_cpu();
 102 }
 103
 104 struct smp_ops_t smp_85xx_ops = {
 105         .kick_cpu = smp_85xx_kick_cpu,
 106 };
 107
 108 void __init mpc85xx_smp_init(void)
 109 {
 110         struct device_node *np;
 111
 112         np = of_find_node_by_type(NULL, "open-pic");
 113         if (np) {
 114                 smp_85xx_ops.probe = smp_mpic_probe;
 115                 smp_85xx_ops.setup_cpu = smp_85xx_setup_cpu;
 116                 smp_85xx_ops.message_pass = smp_mpic_message_pass;
 117         }
 118
 119         if (cpu_has_feature(CPU_FTR_DBELL))
 120                 smp_85xx_ops.message_pass = smp_dbell_message_pass;
 121
 122         BUG_ON(!smp_85xx_ops.message_pass);
 123
 124         smp_ops = &smp_85xx_ops;
 125 }