arch/mips/sibyte/sb1250/smp.c

   1 /*
   2  * Copyright (C) 2001, 2002, 2003 Broadcom Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #include <linux/init.h>
  20 #include <linux/delay.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/smp.h>
  23 #include <linux/kernel_stat.h>
  24
  25 #include <asm/mmu_context.h>
  26 #include <asm/io.h>
  27 #include <asm/fw/cfe/cfe_api.h>
  28 #include <asm/sibyte/sb1250.h>
  29 #include <asm/sibyte/sb1250_regs.h>
  30 #include <asm/sibyte/sb1250_int.h>
  31
  32 static void *mailbox_set_regs[] = {
  33         IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_SET_CPU),
  34         IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_SET_CPU)
  35 };
  36
  37 static void *mailbox_clear_regs[] = {
  38         IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_CLR_CPU),
  39         IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_CLR_CPU)
  40 };
  41
  42 static void *mailbox_regs[] = {
  43         IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_CPU),
  44         IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_CPU)
  45 };
  46
  47 /*
  48  * SMP init and finish on secondary CPUs
  49  */
  50 void __cpuinit sb1250_smp_init(void)
  51 {
  52         unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
  53                 STATUSF_IP1 | STATUSF_IP0;
  54
  55         /* Set interrupt mask, but don't enable */
  56         change_c0_status(ST0_IM, imask);
  57 }
  58
  59 /*
  60  * These are routines for dealing with the sb1250 smp capabilities
  61  * independent of board/firmware
  62  */
  63
  64 /*
  65  * Simple enough; everything is set up, so just poke the appropriate mailbox
  66  * register, and we should be set
  67  */
  68 static void sb1250_send_ipi_single(int cpu, unsigned int action)
  69 {
  70         __raw_writeq((((u64)action) << 48), mailbox_set_regs[cpu]);
  71 }
  72
  73 static inline void sb1250_send_ipi_mask(const struct cpumask *mask,
  74                                         unsigned int action)
  75 {
  76         unsigned int i;
  77
  78         for_each_cpu(i, mask)
  79                 sb1250_send_ipi_single(i, action);
  80 }
  81
  82 /*
  83  * Code to run on secondary just after probing the CPU
  84  */
  85 static void __cpuinit sb1250_init_secondary(void)
  86 {
  87         extern void sb1250_smp_init(void);
  88
  89         sb1250_smp_init();
  90 }
  91
  92 /*
  93  * Do any tidying up before marking online and running the idle
  94  * loop
  95  */
  96 static void __cpuinit sb1250_smp_finish(void)
  97 {
  98         extern void sb1250_clockevent_init(void);
  99
 100         sb1250_clockevent_init();
 101         local_irq_enable();
 102 }
 103
 104 /*
 105  * Final cleanup after all secondaries booted
 106  */
 107 static void sb1250_cpus_done(void)
 108 {
 109 }
 110
 111 /*
 112  * Setup the PC, SP, and GP of a secondary processor and start it
 113  * running!
 114  */
 115 static void __cpuinit sb1250_boot_secondary(int cpu, struct task_struct *idle)
 116 {
 117         int retval;
 118
 119         retval = cfe_cpu_start(cpu_logical_map(cpu), &smp_bootstrap,
 120                                __KSTK_TOS(idle),
 121                                (unsigned long)task_thread_info(idle), 0);
 122         if (retval != 0)
 123                 printk("cfe_start_cpu(%i) returned %i\n" , cpu, retval);
 124 }
 125
 126 /*
 127  * Use CFE to find out how many CPUs are available, setting up
 128  * cpu_possible_map and the logical/physical mappings.
 129  * XXXKW will the boot CPU ever not be physical 0?
 130  *
 131  * Common setup before any secondaries are started
 132  */
 133 static void __init sb1250_smp_setup(void)
 134 {
 135         int i, num;
 136
 137         cpus_clear(cpu_possible_map);
 138         cpu_set(0, cpu_possible_map);
 139         __cpu_number_map[0] = 0;
 140         __cpu_logical_map[0] = 0;
 141
 142         for (i = 1, num = 0; i < NR_CPUS; i++) {
 143                 if (cfe_cpu_stop(i) == 0) {
 144                         cpu_set(i, cpu_possible_map);
 145                         __cpu_number_map[i] = ++num;
 146                         __cpu_logical_map[num] = i;
 147                 }
 148         }
 149         printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
 150 }
 151
 152 static void __init sb1250_prepare_cpus(unsigned int max_cpus)
 153 {
 154 }
 155
 156 struct plat_smp_ops sb_smp_ops = {
 157         .send_ipi_single        = sb1250_send_ipi_single,
 158         .send_ipi_mask          = sb1250_send_ipi_mask,
 159         .init_secondary         = sb1250_init_secondary,
 160         .smp_finish             = sb1250_smp_finish,
 161         .cpus_done              = sb1250_cpus_done,
 162         .boot_secondary         = sb1250_boot_secondary,
 163         .smp_setup              = sb1250_smp_setup,
 164         .prepare_cpus           = sb1250_prepare_cpus,
 165 };
 166
 167 void sb1250_mailbox_interrupt(void)
 168 {
 169         int cpu = smp_processor_id();
 170         int irq = K_INT_MBOX_0;
 171         unsigned int action;
 172
 173         kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
 174         /* Load the mailbox register to figure out what we're supposed to do */
 175         action = (____raw_readq(mailbox_regs[cpu]) >> 48) & 0xffff;
 176
 177         /* Clear the mailbox to clear the interrupt */
 178         ____raw_writeq(((u64)action) << 48, mailbox_clear_regs[cpu]);
 179
 180         /*
 181          * Nothing to do for SMP_RESCHEDULE_YOURSELF; returning from the
 182          * interrupt will do the reschedule for us
 183          */
 184
 185         if (action & SMP_CALL_FUNCTION)
 186                 smp_call_function_interrupt();
 187 }