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 /*
  60  * Handle hypertransport & SMP interrupts. The interrupt lines are scarce.
  61  * For interprocessor interrupts, the best thing to do is to use the INTMSG
  62  * register. We use the same external interrupt line, i.e. INTB3 and monitor
  63  * another status bit
  64  */
  65 static void ll_ht_smp_irq_handler(int irq)
  66 {
  67         u32 status = OCD_READ(RM9000x2_OCD_INTP0STATUS4);
  68
  69         /* Ack all the bits that correspond to the interrupt sources */
  70         if (status != 0)
  71                 OCD_WRITE(RM9000x2_OCD_INTP0STATUS4, IRQ_ACK_BITS);
  72
  73         status = OCD_READ(RM9000x2_OCD_INTP1STATUS4);
  74         if (status != 0)
  75                 OCD_WRITE(RM9000x2_OCD_INTP1STATUS4, IRQ_ACK_BITS);
  76
  77 #ifdef CONFIG_HT_LEVEL_TRIGGER
  78         /*
  79          * Level Trigger Mode only. Send the HT EOI message back to the source.
  80          */
  81         switch (status) {
  82         case 0x1000000:
  83                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTA);
  84                 break;
  85         case 0x2000000:
  86                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTB);
  87                 break;
  88         case 0x4000000:
  89                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTC);
  90                 break;
  91         case 0x8000000:
  92                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTD);
  93                 break;
  94         case 0x0000001:
  95                 /* PLX */
  96                 OCD_WRITE(RM9000x2_OCD_HTEOI, 0x20);
  97                 OCD_WRITE(IRQ_CLEAR_REG, IRQ_ACK_BITS);
  98                 break;
  99         case 0xf000000:
 100                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTA);
 101                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTB);
 102                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTC);
 103                 OCD_WRITE(RM9000x2_OCD_HTEOI, HYPERTRANSPORT_INTD);
 104                 break;
 105         }
 106 #endif /* CONFIG_HT_LEVEL_TRIGGER */
 107
 108         do_IRQ(irq);
 109 }
 110
 111 asmlinkage void plat_irq_dispatch(void)
 112 {
 113         unsigned int cause = read_c0_cause();
 114         unsigned int status = read_c0_status();
 115         unsigned int pending = cause & status;
 116
 117         if (pending & STATUSF_IP7) {
 118                 do_IRQ(7);
 119         } else if (pending & STATUSF_IP2) {
 120 #ifdef CONFIG_HYPERTRANSPORT
 121                 ll_ht_smp_irq_handler(2);
 122 #else
 123                 do_IRQ(2);
 124 #endif
 125         } else if (pending & STATUSF_IP3) {
 126                 do_IRQ(3);
 127         } else if (pending & STATUSF_IP4) {
 128                 do_IRQ(4);
 129         } else if (pending & STATUSF_IP5) {
 130 #ifdef CONFIG_SMP
 131                 titan_mailbox_irq();
 132 #else
 133                 do_IRQ(5);
 134 #endif
 135         } else if (pending & STATUSF_IP6) {
 136                 do_IRQ(4);
 137         }
 138 }
 139
 140 #ifdef CONFIG_KGDB
 141 extern void init_second_port(void);
 142 #endif
 143
 144 /*
 145  * Initialize the next level interrupt handler
 146  */
 147 void __init arch_init_irq(void)
 148 {
 149         clear_c0_status(ST0_IM);
 150
 151         mips_cpu_irq_init();
 152         rm7k_cpu_irq_init();
 153         rm9k_cpu_irq_init();
 154
 155 #ifdef CONFIG_KGDB
 156         /* At this point, initialize the second serial port */
 157         init_second_port();
 158 #endif
 159
 160 #ifdef CONFIG_GDB_CONSOLE
 161         register_gdb_console();
 162 #endif
 163 }