| /* |
| * arch/mips/dec/int-handler.S |
| * |
| * Copyright (C) 1995, 1996, 1997 Paul M. Antoine and Harald Koerfgen |
| * Copyright (C) 2000, 2001, 2002, 2003, 2005 Maciej W. Rozycki |
| * |
| * Written by Ralf Baechle and Andreas Busse, modified for DECstation |
| * support by Paul Antoine and Harald Koerfgen. |
| * |
| * completly rewritten: |
| * Copyright (C) 1998 Harald Koerfgen |
| * |
| * Rewritten extensively for controller-driven IRQ support |
| * by Maciej W. Rozycki. |
| */ |
| |
| #include <asm/addrspace.h> |
| #include <asm/asm.h> |
| #include <asm/mipsregs.h> |
| #include <asm/regdef.h> |
| #include <asm/stackframe.h> |
| |
| #include <asm/dec/interrupts.h> |
| #include <asm/dec/ioasic_addrs.h> |
| #include <asm/dec/ioasic_ints.h> |
| #include <asm/dec/kn01.h> |
| #include <asm/dec/kn02.h> |
| #include <asm/dec/kn02xa.h> |
| #include <asm/dec/kn03.h> |
| |
| #define KN02_CSR_BASE CKSEG1ADDR(KN02_SLOT_BASE + KN02_CSR) |
| #define KN02XA_IOASIC_BASE CKSEG1ADDR(KN02XA_SLOT_BASE + IOASIC_IOCTL) |
| #define KN03_IOASIC_BASE CKSEG1ADDR(KN03_SLOT_BASE + IOASIC_IOCTL) |
| |
| .text |
| .set noreorder |
| /* |
| * plat_irq_dispatch: Interrupt handler for DECstations |
| * |
| * We follow the model in the Indy interrupt code by David Miller, where he |
| * says: a lot of complication here is taken away because: |
| * |
| * 1) We handle one interrupt and return, sitting in a loop |
| * and moving across all the pending IRQ bits in the cause |
| * register is _NOT_ the answer, the common case is one |
| * pending IRQ so optimize in that direction. |
| * |
| * 2) We need not check against bits in the status register |
| * IRQ mask, that would make this routine slow as hell. |
| * |
| * 3) Linux only thinks in terms of all IRQs on or all IRQs |
| * off, nothing in between like BSD spl() brain-damage. |
| * |
| * Furthermore, the IRQs on the DECstations look basically (barring |
| * software IRQs which we don't use at all) like... |
| * |
| * DS2100/3100's, aka kn01, aka Pmax: |
| * |
| * MIPS IRQ Source |
| * -------- ------ |
| * 0 Software (ignored) |
| * 1 Software (ignored) |
| * 2 SCSI |
| * 3 Lance Ethernet |
| * 4 DZ11 serial |
| * 5 RTC |
| * 6 Memory Controller & Video |
| * 7 FPU |
| * |
| * DS5000/200, aka kn02, aka 3max: |
| * |
| * MIPS IRQ Source |
| * -------- ------ |
| * 0 Software (ignored) |
| * 1 Software (ignored) |
| * 2 TurboChannel |
| * 3 RTC |
| * 4 Reserved |
| * 5 Memory Controller |
| * 6 Reserved |
| * 7 FPU |
| * |
| * DS5000/1xx's, aka kn02ba, aka 3min: |
| * |
| * MIPS IRQ Source |
| * -------- ------ |
| * 0 Software (ignored) |
| * 1 Software (ignored) |
| * 2 TurboChannel Slot 0 |
| * 3 TurboChannel Slot 1 |
| * 4 TurboChannel Slot 2 |
| * 5 TurboChannel Slot 3 (ASIC) |
| * 6 Halt button |
| * 7 FPU/R4k timer |
| * |
| * DS5000/2x's, aka kn02ca, aka maxine: |
| * |
| * MIPS IRQ Source |
| * -------- ------ |
| * 0 Software (ignored) |
| * 1 Software (ignored) |
| * 2 Periodic Interrupt (100usec) |
| * 3 RTC |
| * 4 I/O write timeout |
| * 5 TurboChannel (ASIC) |
| * 6 Halt Keycode from Access.Bus keyboard (CTRL-ALT-ENTER) |
| * 7 FPU/R4k timer |
| * |
| * DS5000/2xx's, aka kn03, aka 3maxplus: |
| * |
| * MIPS IRQ Source |
| * -------- ------ |
| * 0 Software (ignored) |
| * 1 Software (ignored) |
| * 2 System Board (ASIC) |
| * 3 RTC |
| * 4 Reserved |
| * 5 Memory |
| * 6 Halt Button |
| * 7 FPU/R4k timer |
| * |
| * We handle the IRQ according to _our_ priority (see setup.c), |
| * then we just return. If multiple IRQs are pending then we will |
| * just take another exception, big deal. |
| */ |
| .align 5 |
| NESTED(plat_irq_dispatch, PT_SIZE, ra) |
| .set noreorder |
| |
| /* |
| * Get pending Interrupts |
| */ |
| mfc0 t0,CP0_CAUSE # get pending interrupts |
| mfc0 t1,CP0_STATUS |
| #ifdef CONFIG_32BIT |
| lw t2,cpu_fpu_mask |
| #endif |
| andi t0,ST0_IM # CAUSE.CE may be non-zero! |
| and t0,t1 # isolate allowed ones |
| |
| beqz t0,spurious |
| |
| #ifdef CONFIG_32BIT |
| and t2,t0 |
| bnez t2,fpu # handle FPU immediately |
| #endif |
| |
| /* |
| * Find irq with highest priority |
| */ |
| PTR_LA t1,cpu_mask_nr_tbl |
| 1: lw t2,(t1) |
| nop |
| and t2,t0 |
| beqz t2,1b |
| addu t1,2*PTRSIZE # delay slot |
| |
| /* |
| * Do the low-level stuff |
| */ |
| lw a0,(-PTRSIZE)(t1) |
| nop |
| bgez a0,handle_it # irq_nr >= 0? |
| # irq_nr < 0: it is an address |
| nop |
| jr a0 |
| # a trick to save a branch: |
| lui t2,(KN03_IOASIC_BASE>>16)&0xffff |
| # upper part of IOASIC Address |
| |
| /* |
| * Handle "IRQ Controller" Interrupts |
| * Masked Interrupts are still visible and have to be masked "by hand". |
| */ |
| FEXPORT(kn02_io_int) # 3max |
| lui t0,(KN02_CSR_BASE>>16)&0xffff |
| # get interrupt status and mask |
| lw t0,(t0) |
| nop |
| andi t1,t0,KN02_IRQ_ALL |
| b 1f |
| srl t0,16 # shift interrupt mask |
| |
| FEXPORT(kn02xa_io_int) # 3min/maxine |
| lui t2,(KN02XA_IOASIC_BASE>>16)&0xffff |
| # upper part of IOASIC Address |
| |
| FEXPORT(kn03_io_int) # 3max+ (t2 loaded earlier) |
| lw t0,IO_REG_SIR(t2) # get status: IOASIC sir |
| lw t1,IO_REG_SIMR(t2) # get mask: IOASIC simr |
| nop |
| |
| 1: and t0,t1 # mask out allowed ones |
| |
| beqz t0,spurious |
| |
| /* |
| * Find irq with highest priority |
| */ |
| PTR_LA t1,asic_mask_nr_tbl |
| 2: lw t2,(t1) |
| nop |
| and t2,t0 |
| beq zero,t2,2b |
| addu t1,2*PTRSIZE # delay slot |
| |
| /* |
| * Do the low-level stuff |
| */ |
| lw a0,%lo(-PTRSIZE)(t1) |
| nop |
| bgez a0,handle_it # irq_nr >= 0? |
| # irq_nr < 0: it is an address |
| nop |
| jr a0 |
| nop # delay slot |
| |
| /* |
| * Dispatch low-priority interrupts. We reconsider all status |
| * bits again, which looks like a lose, but it makes the code |
| * simple and O(log n), so it gets compensated. |
| */ |
| FEXPORT(cpu_all_int) # HALT, timers, software junk |
| li a0,DEC_CPU_IRQ_BASE |
| srl t0,CAUSEB_IP |
| li t1,CAUSEF_IP>>CAUSEB_IP # mask |
| b 1f |
| li t2,4 # nr of bits / 2 |
| |
| FEXPORT(kn02_all_int) # impossible ? |
| li a0,KN02_IRQ_BASE |
| li t1,KN02_IRQ_ALL # mask |
| b 1f |
| li t2,4 # nr of bits / 2 |
| |
| FEXPORT(asic_all_int) # various I/O ASIC junk |
| li a0,IO_IRQ_BASE |
| li t1,IO_IRQ_ALL # mask |
| b 1f |
| li t2,8 # nr of bits / 2 |
| |
| /* |
| * Dispatch DMA interrupts -- O(log n). |
| */ |
| FEXPORT(asic_dma_int) # I/O ASIC DMA events |
| li a0,IO_IRQ_BASE+IO_INR_DMA |
| srl t0,IO_INR_DMA |
| li t1,IO_IRQ_DMA>>IO_INR_DMA # mask |
| li t2,8 # nr of bits / 2 |
| |
| /* |
| * Find irq with highest priority. |
| * Highest irq number takes precedence. |
| */ |
| 1: srlv t3,t1,t2 |
| 2: xor t1,t3 |
| and t3,t0,t1 |
| beqz t3,3f |
| nop |
| move t0,t3 |
| addu a0,t2 |
| 3: srl t2,1 |
| bnez t2,2b |
| srlv t3,t1,t2 |
| |
| handle_it: |
| LONG_L s0, TI_REGS($28) |
| LONG_S sp, TI_REGS($28) |
| PTR_LA ra, ret_from_irq |
| j do_IRQ |
| nop |
| |
| #ifdef CONFIG_32BIT |
| fpu: |
| j handle_fpe_int |
| nop |
| #endif |
| |
| spurious: |
| PTR_LA ra, _ret_from_irq |
| j spurious_interrupt |
| nop |
| END(plat_irq_dispatch) |
| |
| /* |
| * Generic unimplemented interrupt routines -- cpu_mask_nr_tbl |
| * and asic_mask_nr_tbl are initialized to point all interrupts here. |
| * The tables are then filled in by machine-specific initialisation |
| * in dec_setup(). |
| */ |
| FEXPORT(dec_intr_unimplemented) |
| move a1,t0 # cheats way of printing an arg! |
| PANIC("Unimplemented cpu interrupt! CP0_CAUSE: 0x%08x"); |
| |
| FEXPORT(asic_intr_unimplemented) |
| move a1,t0 # cheats way of printing an arg! |
| PANIC("Unimplemented asic interrupt! ASIC ISR: 0x%08x"); |