Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2000, 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 | /* |
| 20 | * sb1250_handle_int() is the routine that is actually called when an interrupt |
| 21 | * occurs. It is installed as the exception vector handler in arch_init_irq() |
| 22 | * in arch/mips/sibyte/sb1250/irq.c |
| 23 | * |
| 24 | * In the handle we figure out which interrupts need handling, and use that to |
| 25 | * call the dispatcher, which will take care of actually calling registered |
| 26 | * handlers |
| 27 | * |
| 28 | * Note that we take care of all raised interrupts in one go at the handler. |
| 29 | * This is more BSDish than the Indy code, and also, IMHO, more sane. |
| 30 | */ |
| 31 | #include <linux/config.h> |
| 32 | |
| 33 | #include <asm/addrspace.h> |
| 34 | #include <asm/asm.h> |
| 35 | #include <asm/mipsregs.h> |
| 36 | #include <asm/regdef.h> |
| 37 | #include <asm/stackframe.h> |
| 38 | #include <asm/sibyte/sb1250_defs.h> |
| 39 | #include <asm/sibyte/sb1250_regs.h> |
| 40 | #include <asm/sibyte/sb1250_int.h> |
| 41 | |
| 42 | /* |
| 43 | * What a pain. We have to be really careful saving the upper 32 bits of any |
| 44 | * register across function calls if we don't want them trashed--since were |
| 45 | * running in -o32, the calling routing never saves the full 64 bits of a |
| 46 | * register across a function call. Being the interrupt handler, we're |
| 47 | * guaranteed that interrupts are disabled during this code so we don't have |
| 48 | * to worry about random interrupts blasting the high 32 bits. |
| 49 | */ |
| 50 | |
| 51 | .text |
| 52 | .set push |
| 53 | .set noreorder |
| 54 | .set noat |
| 55 | .set mips64 |
| 56 | .align 5 |
| 57 | NESTED(sb1250_irq_handler, PT_SIZE, sp) |
| 58 | SAVE_ALL |
| 59 | CLI |
| 60 | |
| 61 | #ifdef CONFIG_SIBYTE_SB1250_PROF |
| 62 | /* Set compare to count to silence count/compare timer interrupts */ |
| 63 | mfc0 t1, CP0_COUNT |
| 64 | mtc0 t1, CP0_COMPARE /* pause to clear IP[7] bit of cause ? */ |
| 65 | #endif |
| 66 | /* Read cause */ |
| 67 | mfc0 s0, CP0_CAUSE |
| 68 | |
| 69 | #ifdef CONFIG_SIBYTE_SB1250_PROF |
| 70 | /* Cpu performance counter interrupt is routed to IP[7] */ |
| 71 | andi t1, s0, CAUSEF_IP7 |
| 72 | beqz t1, 0f |
| 73 | srl t1, s0, (CAUSEB_BD-2) /* Shift BD bit to bit 2 */ |
| 74 | and t1, t1, 0x4 /* mask to get just BD bit */ |
| 75 | mfc0 a0, CP0_EPC |
| 76 | jal sbprof_cpu_intr |
| 77 | addu a0, a0, t1 /* a0 = EPC + (BD ? 4 : 0) */ |
| 78 | j ret_from_irq |
| 79 | nop |
| 80 | 0: |
| 81 | #endif |
| 82 | |
| 83 | /* Timer interrupt is routed to IP[4] */ |
| 84 | andi t1, s0, CAUSEF_IP4 |
| 85 | beqz t1, 1f |
| 86 | nop |
| 87 | jal sb1250_timer_interrupt |
| 88 | move a0, sp /* Pass the registers along */ |
| 89 | j ret_from_irq |
| 90 | nop # delay slot |
| 91 | 1: |
| 92 | |
| 93 | #ifdef CONFIG_SMP |
| 94 | /* Mailbox interrupt is routed to IP[3] */ |
| 95 | andi t1, s0, CAUSEF_IP3 |
| 96 | beqz t1, 2f |
| 97 | nop |
| 98 | jal sb1250_mailbox_interrupt |
| 99 | move a0, sp |
| 100 | j ret_from_irq |
| 101 | nop # delay slot |
| 102 | 2: |
| 103 | #endif |
| 104 | |
| 105 | #ifdef CONFIG_KGDB |
| 106 | /* KGDB (uart 1) interrupt is routed to IP[6] */ |
| 107 | andi t1, s0, CAUSEF_IP6 |
| 108 | beqz t1, 1f |
| 109 | nop # delay slot |
| 110 | jal sb1250_kgdb_interrupt |
| 111 | move a0, sp |
| 112 | j ret_from_irq |
| 113 | nop # delay slot |
| 114 | 1: |
| 115 | #endif |
| 116 | |
| 117 | and t1, s0, CAUSEF_IP2 |
| 118 | beqz t1, 4f |
| 119 | nop |
| 120 | |
| 121 | /* |
| 122 | * Default...we've hit an IP[2] interrupt, which means we've got to |
| 123 | * check the 1250 interrupt registers to figure out what to do |
| 124 | * Need to detect which CPU we're on, now that smp_affinity is supported. |
| 125 | */ |
| 126 | PTR_LA v0, CKSEG1 + A_IMR_CPU0_BASE |
| 127 | #ifdef CONFIG_SMP |
| 128 | lw t1, TI_CPU($28) |
| 129 | sll t1, IMR_REGISTER_SPACING_SHIFT |
| 130 | addu v0, t1 |
| 131 | #endif |
| 132 | ld s0, R_IMR_INTERRUPT_STATUS_BASE(v0) /* read IP[2] status */ |
| 133 | |
| 134 | beqz s0, 4f /* No interrupts. Return */ |
| 135 | move a1, sp |
| 136 | |
| 137 | 3: dclz s1, s0 /* Find the next interrupt */ |
| 138 | dsubu a0, zero, s1 |
| 139 | daddiu a0, a0, 63 |
| 140 | jal do_IRQ |
| 141 | nop |
| 142 | |
| 143 | 4: j ret_from_irq |
| 144 | nop |
| 145 | |
| 146 | .set pop |
| 147 | END(sb1250_irq_handler) |