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/sibyte/sb1250.h>
  28 #include <asm/sibyte/sb1250_regs.h>
  29 #include <asm/sibyte/sb1250_int.h>
  30
  31 static void *mailbox_set_regs[] = {
  32         (void *)IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_SET_CPU),
  33         (void *)IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_SET_CPU)
  34 };
  35
  36 static void *mailbox_clear_regs[] = {
  37         (void *)IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_CLR_CPU),
  38         (void *)IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_CLR_CPU)
  39 };
  40
  41 static void *mailbox_regs[] = {
  42         (void *)IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_CPU),
  43         (void *)IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_CPU)
  44 };
  45
  46 /*
  47  * SMP init and finish on secondary CPUs
  48  */
  49 void sb1250_smp_init(void)
  50 {
  51         unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
  52                 STATUSF_IP1 | STATUSF_IP0;
  53
  54         /* Set interrupt mask, but don't enable */
  55         change_c0_status(ST0_IM, imask);
  56 }
  57
  58 void sb1250_smp_finish(void)
  59 {
  60         extern void sb1250_time_init(void);
  61         sb1250_time_init();
  62         local_irq_enable();
  63 }
  64
  65 /*
  66  * These are routines for dealing with the sb1250 smp capabilities
  67  * independent of board/firmware
  68  */
  69
  70 /*
  71  * Simple enough; everything is set up, so just poke the appropriate mailbox
  72  * register, and we should be set
  73  */
  74 void core_send_ipi(int cpu, unsigned int action)
  75 {
  76         bus_writeq((((u64)action) << 48), mailbox_set_regs[cpu]);
  77 }
  78
  79 void sb1250_mailbox_interrupt(struct pt_regs *regs)
  80 {
  81         int cpu = smp_processor_id();
  82         unsigned int action;
  83
  84         kstat_this_cpu.irqs[K_INT_MBOX_0]++;
  85         /* Load the mailbox register to figure out what we're supposed to do */
  86         action = (__bus_readq(mailbox_regs[cpu]) >> 48) & 0xffff;
  87
  88         /* Clear the mailbox to clear the interrupt */
  89         __bus_writeq(((u64)action) << 48, mailbox_clear_regs[cpu]);
  90
  91         /*
  92          * Nothing to do for SMP_RESCHEDULE_YOURSELF; returning from the
  93          * interrupt will do the reschedule for us
  94          */
  95
  96         if (action & SMP_CALL_FUNCTION)
  97                 smp_call_function_interrupt();
  98 }