arch/sh/kernel/cpu/sh4a/smp-shx3.c

   1 /*
   2  * SH-X3 SMP
   3  *
   4  *  Copyright (C) 2007 - 2008  Paul Mundt
   5  *  Copyright (C) 2007  Magnus Damm
   6  *
   7  * This file is subject to the terms and conditions of the GNU General Public
   8  * License.  See the file "COPYING" in the main directory of this archive
   9  * for more details.
  10  */
  11 #include <linux/init.h>
  12 #include <linux/cpumask.h>
  13 #include <linux/smp.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/io.h>
  16
  17 static irqreturn_t ipi_interrupt_handler(int irq, void *arg)
  18 {
  19         unsigned int message = (unsigned int)(long)arg;
  20         unsigned int cpu = hard_smp_processor_id();
  21         unsigned int offs = 4 * cpu;
  22         unsigned int x;
  23
  24         x = ctrl_inl(0xfe410070 + offs); /* C0INITICI..CnINTICI */
  25         x &= (1 << (message << 2));
  26         ctrl_outl(x, 0xfe410080 + offs); /* C0INTICICLR..CnINTICICLR */
  27
  28         smp_message_recv(message);
  29
  30         return IRQ_HANDLED;
  31 }
  32
  33 void __init plat_smp_setup(void)
  34 {
  35         unsigned int cpu = 0;
  36         int i, num;
  37
  38         init_cpu_possible(cpumask_of(cpu));
  39
  40         __cpu_number_map[0] = 0;
  41         __cpu_logical_map[0] = 0;
  42
  43         /*
  44          * Do this stupidly for now.. we don't have an easy way to probe
  45          * for the total number of cores.
  46          */
  47         for (i = 1, num = 0; i < NR_CPUS; i++) {
  48                 set_cpu_possible(i, true);
  49                 __cpu_number_map[i] = ++num;
  50                 __cpu_logical_map[num] = i;
  51         }
  52
  53         printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
  54 }
  55
  56 void __init plat_prepare_cpus(unsigned int max_cpus)
  57 {
  58         int i;
  59
  60         BUILD_BUG_ON(SMP_MSG_NR >= 8);
  61
  62         for (i = 0; i < SMP_MSG_NR; i++)
  63                 request_irq(104 + i, ipi_interrupt_handler, IRQF_DISABLED,
  64                             "IPI", (void *)(long)i);
  65 }
  66
  67 #define STBCR_REG(phys_id) (0xfe400004 | (phys_id << 12))
  68 #define RESET_REG(phys_id) (0xfe400008 | (phys_id << 12))
  69
  70 #define STBCR_MSTP      0x00000001
  71 #define STBCR_RESET     0x00000002
  72 #define STBCR_LTSLP     0x80000000
  73
  74 #define STBCR_AP_VAL    (STBCR_RESET | STBCR_LTSLP)
  75
  76 void plat_start_cpu(unsigned int cpu, unsigned long entry_point)
  77 {
  78         ctrl_outl(entry_point, RESET_REG(cpu));
  79
  80         if (!(ctrl_inl(STBCR_REG(cpu)) & STBCR_MSTP))
  81                 ctrl_outl(STBCR_MSTP, STBCR_REG(cpu));
  82
  83         while (!(ctrl_inl(STBCR_REG(cpu)) & STBCR_MSTP))
  84                 cpu_relax();
  85
  86         /* Start up secondary processor by sending a reset */
  87         ctrl_outl(STBCR_AP_VAL, STBCR_REG(cpu));
  88 }
  89
  90 int plat_smp_processor_id(void)
  91 {
  92         return ctrl_inl(0xff000048); /* CPIDR */
  93 }
  94
  95 void plat_send_ipi(unsigned int cpu, unsigned int message)
  96 {
  97         unsigned long addr = 0xfe410070 + (cpu * 4);
  98
  99         BUG_ON(cpu >= 4);
 100
 101         ctrl_outl(1 << (message << 2), addr); /* C0INTICI..CnINTICI */
 102 }