arch/mips/pmc-sierra/yosemite/irq.c

   1 /*
   2  * Copyright (C) 2003 PMC-Sierra Inc.
   3  * Author: Manish Lachwani (lachwani@pmc-sierra.com)
   4  *
   5  * Copyright (C) 2006 Ralf Baechle (ralf@linux-mips.org)
   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  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  13  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  14  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  15  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  16  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  17  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  18  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  19  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  20  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  21  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  22  *
  23  *  You should have received a copy of the  GNU General Public License along
  24  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  25  *  675 Mass Ave, Cambridge, MA 02139, USA.
  26  *
  27  * Second level Interrupt handlers for the PMC-Sierra Titan/Yosemite board
  28  */
  29 #include <linux/errno.h>
  30 #include <linux/init.h>
  31 #include <linux/kernel_stat.h>
  32 #include <linux/module.h>
  33 #include <linux/signal.h>
  34 #include <linux/sched.h>
  35 #include <linux/types.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/ioport.h>
  38 #include <linux/irq.h>
  39 #include <linux/timex.h>
  40 #include <linux/slab.h>
  41 #include <linux/random.h>
  42 #include <linux/bitops.h>
  43 #include <asm/bootinfo.h>
  44 #include <asm/io.h>
  45 #include <asm/irq.h>
  46 #include <asm/irq_cpu.h>
  47 #include <asm/mipsregs.h>
  48 #include <asm/system.h>
  49 #include <asm/titan_dep.h>
  50
  51 /* Hypertransport specific */
  52 #define IRQ_ACK_BITS            0x00000000      /* Ack bits */
  53
  54 #define HYPERTRANSPORT_INTA     0x78            /* INTA# */
  55 #define HYPERTRANSPORT_INTB     0x79            /* INTB# */
  56 #define HYPERTRANSPORT_INTC     0x7a            /* INTC# */
  57 #define HYPERTRANSPORT_INTD     0x7b            /* INTD# */
  58
  59 extern void titan_mailbox_irq(void);
  60
  61 #ifdef CONFIG_HYPERTRANSPORT
  62 /*
  63  * Handle hypertransport & SMP interrupts. The interrupt lines are scarce.
  64  * For interprocessor interrupts, the best thing to do is to use the INTMSG
  65  * register. We use the same external interrupt line, i.e. INTB3 and monitor
  66  * another status bit
  67  */
  68 static void ll_ht_smp_irq_handler(int irq)
  69 {
  70         u32 status = OCD_READ(RM9000x2_OCD_INTP0STATUS4);
  71
  72         /* Ack all the bits that correspond to the interrupt sources */
  73         if (status != 0)
  74                 OCD_WRITE(RM9000x2_OCD_INTP0STATUS4, IRQ_ACK_BITS);
  75
  76         status = OCD_READ(RM9000x2_OCD_INTP1STATUS4);
  77         if (status != 0)
  78                 OCD_WRITE(RM9000x2_OCD_INTP1STATUS4, IRQ_ACK_BITS);
  79
  80 #ifdef CONFIG_HT_LEVEL_TRIGGER
  81         /*
  82          * Level Trigger Mode only. Send the HT EOI message back to the source.
  83          */
  84         switch (status) {
  85         case 0x1000000:
  86                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTA);
  87                 break;
  88         case 0x2000000:
  89                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTB);
  90                 break;
  91         case 0x4000000:
  92                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTC);
  93                 break;
  94         case 0x8000000:
  95                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTD);
  96                 break;
  97         case 0x0000001:
  98                 /* PLX */
  99                 OCD_WRITE(RM9000x2_OCD_HTEOI, 0x20);
 100                 OCD_WRITE(IRQ_CLEAR_REG, IRQ_ACK_BITS);
 101                 break;
 102         case 0xf000000:
 103                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTA);
 104                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTB);
 105                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTC);
 106                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTD);
 107                 break;
 108         }
 109 #endif /* CONFIG_HT_LEVEL_TRIGGER */
 110
 111         do_IRQ(irq);
 112 }
 113 #endif
 114
 115 asmlinkage void plat_irq_dispatch(void)
 116 {
 117         unsigned int cause = read_c0_cause();
 118         unsigned int status = read_c0_status();
 119         unsigned int pending = cause & status;
 120
 121         if (pending & STATUSF_IP7) {
 122                 do_IRQ(7);
 123         } else if (pending & STATUSF_IP2) {
 124 #ifdef CONFIG_HYPERTRANSPORT
 125                 ll_ht_smp_irq_handler(2);
 126 #else
 127                 do_IRQ(2);
 128 #endif
 129         } else if (pending & STATUSF_IP3) {
 130                 do_IRQ(3);
 131         } else if (pending & STATUSF_IP4) {
 132                 do_IRQ(4);
 133         } else if (pending & STATUSF_IP5) {
 134 #ifdef CONFIG_SMP
 135                 titan_mailbox_irq();
 136 #else
 137                 do_IRQ(5);
 138 #endif
 139         } else if (pending & STATUSF_IP6) {
 140                 do_IRQ(4);
 141         }
 142 }
 143
 144 #ifdef CONFIG_KGDB
 145 extern void init_second_port(void);
 146 #endif
 147
 148 /*
 149  * Initialize the next level interrupt handler
 150  */
 151 void __init arch_init_irq(void)
 152 {
 153         clear_c0_status(ST0_IM);
 154
 155         mips_cpu_irq_init();
 156         rm7k_cpu_irq_init();
 157         rm9k_cpu_irq_init();
 158
 159 #ifdef CONFIG_KGDB
 160         /* At this point, initialize the second serial port */
 161         init_second_port();
 162 #endif
 163
 164 #ifdef CONFIG_GDB_CONSOLE
 165         register_gdb_console();
 166 #endif
 167 }