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Diffstat (limited to 'arch/mips/jazz/int-handler.S')
| -rw-r--r-- | arch/mips/jazz/int-handler.S | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/arch/mips/jazz/int-handler.S b/arch/mips/jazz/int-handler.S new file mode 100644 index 00000000000..4dbcf91db88 --- /dev/null +++ b/arch/mips/jazz/int-handler.S @@ -0,0 +1,282 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1995, 1996, 1997, 1998 by Ralf Baechle and Andreas Busse + * + * Jazz family specific interrupt stuff + * + * To do: On Jazz machines we remap some non-ISA interrupts to ISA + * interrupts. These interrupts should use their own vectors. + * Squeeze the last cycles out of the handlers. Only a dead + * cycle is a good cycle. + */ +#include <asm/asm.h> +#include <asm/mipsregs.h> +#include <asm/jazz.h> +#include <asm/regdef.h> +#include <asm/stackframe.h> + +/* + * jazz_handle_int: Interrupt handler for the ACER Pica-61 boards + */ + .set noreorder + + NESTED(jazz_handle_int, PT_SIZE, ra) + .set noat + SAVE_ALL + CLI + .set at + + /* + * Get pending interrupts + */ + mfc0 t0,CP0_CAUSE # get pending interrupts + mfc0 t1,CP0_STATUS # get enabled interrupts + and t0,t1 # isolate allowed ones + andi t0,0xff00 # isolate pending bits + beqz t0,3f + sll t0,16 # delay slot + + /* + * Find irq with highest priority + * FIXME: This is slow - use binary search + */ + la t1,ll_vectors +1: bltz t0,2f # found pending irq + sll t0,1 + b 1b + subu t1,PTRSIZE # delay slot + + /* + * Do the low-level stuff + */ +2: lw t0,(t1) + jr t0 + nop # delay slot + END(jazz_handle_int) + +ll_sw0: li s1,~IE_SW0 + mfc0 t0,CP0_CAUSE + and t0,s1 + mtc0 t0,CP0_CAUSE + PANIC("Unimplemented sw0 handler") + +ll_sw1: li s1,~IE_SW1 + mfc0 t0,CP0_CAUSE + and t0,s1 + mtc0 t0,CP0_CAUSE + PANIC("Unimplemented sw1 handler") + +ll_local_dma: li s1,~IE_IRQ0 + PANIC("Unimplemented local_dma handler") + +ll_local_dev: lbu t0,JAZZ_IO_IRQ_SOURCE +#if PTRSIZE == 8 /* True 64 bit kernel */ + dsll t0,1 +#endif + .set reorder + LONG_L t0,local_vector(t0) + jr t0 + .set noreorder + +/* + * The braindead PICA hardware gives us no way to distinguish if we really + * received interrupt 7 from the (E)ISA bus or if we just received an + * interrupt with no findable cause. This sometimes happens with braindead + * cards. Oh well - for all the Jazz boxes slots are more or less just + * whistles and bells and we're aware of the problem. + */ +ll_isa_irq: lw a0, JAZZ_EISA_IRQ_ACK + + jal do_IRQ + move a1,sp + + j ret_from_irq + nop + +/* + * Hmm... This is not just a plain PC clone so the question is + * which devices on Jazz machines can generate an (E)ISA NMI? + * (Writing to nonexistent memory?) + */ +ll_isa_nmi: li s1,~IE_IRQ3 + PANIC("Unimplemented isa_nmi handler") + +/* + * Timer IRQ - remapped to be more similar to an IBM compatible. + * + * The timer interrupt is handled specially to ensure that the jiffies + * variable is updated at all times. Specifically, the timer interrupt is + * just like the complete handlers except that it is invoked with interrupts + * disabled and should never re-enable them. If other interrupts were + * allowed to be processed while the timer interrupt is active, then the + * other interrupts would have to avoid using the jiffies variable for delay + * and interval timing operations to avoid hanging the system. + */ +ll_timer: lw zero,JAZZ_TIMER_REGISTER # timer irq cleared on read + li s1,~IE_IRQ4 + + li a0, JAZZ_TIMER_IRQ + jal do_IRQ + move a1,sp + + mfc0 t0,CP0_STATUS # disable interrupts again + ori t0,1 + xori t0,1 + mtc0 t0,CP0_STATUS + + j ret_from_irq + nop + +/* + * CPU count/compare IRQ (unused) + */ +ll_count: j ret_from_irq + mtc0 zero,CP0_COMPARE + +#if 0 +/* + * Call the handler for the interrupt + * (Currently unused) + */ +call_real: /* + * temporarily disable interrupt + */ + mfc0 t2,CP0_STATUS + and t2,s1 + mtc0 t2,CP0_STATUS + nor s1,zero,s1 + jal do_IRQ + + /* + * reenable interrupt + */ + mfc0 t2,CP0_STATUS + or t2,s1 + mtc0 t2,CP0_STATUS + j ret_from_irq +#endif + + .data + PTR ll_sw0 # SW0 + PTR ll_sw1 # SW1 + PTR ll_local_dma # Local DMA + PTR ll_local_dev # Local devices + PTR ll_isa_irq # ISA IRQ + PTR ll_isa_nmi # ISA NMI + PTR ll_timer # Timer +ll_vectors: PTR ll_count # Count/Compare IRQ + + /* + * Interrupt handlers for local devices. + */ + .text + .set reorder +loc_no_irq: PANIC("Unimplemented loc_no_irq handler") +/* + * Parallel port IRQ + */ +loc_parallel: li s1,~JAZZ_IE_PARALLEL + li a0,JAZZ_PARALLEL_IRQ + b loc_call + +/* + * Floppy IRQ + */ +loc_floppy: li s1,~JAZZ_IE_FLOPPY + li a0,JAZZ_FLOPPY_IRQ + b loc_call + +/* + * Sound IRQ + */ +loc_sound: PANIC("Unimplemented loc_sound handler") +loc_video: PANIC("Unimplemented loc_video handler") + +/* + * Ethernet interrupt handler + */ +loc_ethernet: li s1,~JAZZ_IE_ETHERNET + li a0,JAZZ_ETHERNET_IRQ + b loc_call + +/* + * SCSI interrupt handler + */ +loc_scsi: li s1,~JAZZ_IE_SCSI + li a0,JAZZ_SCSI_IRQ + b loc_call + +/* + * Keyboard interrupt handler + */ +loc_keyboard: li s1,~JAZZ_IE_KEYBOARD + li a0,JAZZ_KEYBOARD_IRQ + b loc_call + +/* + * Mouse interrupt handler + */ +loc_mouse: li s1,~JAZZ_IE_MOUSE + li a0,JAZZ_MOUSE_IRQ + b loc_call + +/* + * Serial port 1 IRQ + */ +loc_serial1: li s1,~JAZZ_IE_SERIAL1 + li a0,JAZZ_SERIAL1_IRQ + b loc_call + +/* + * Serial port 2 IRQ + */ +loc_serial2: li s1,~JAZZ_IE_SERIAL2 + li a0,JAZZ_SERIAL2_IRQ + b loc_call + +/* + * Call the interrupt handler for an interrupt generated by a + * local device. + */ +loc_call: /* + * Temporarily disable interrupt source + */ + lhu t2,JAZZ_IO_IRQ_ENABLE + and t2,s1 + sh t2,JAZZ_IO_IRQ_ENABLE + + nor s1,zero,s1 + jal do_IRQ + + /* + * Reenable interrupt + */ + lhu t2,JAZZ_IO_IRQ_ENABLE + or t2,s1 + sh t2,JAZZ_IO_IRQ_ENABLE + + j ret_from_irq + +/* + * "Jump extender" to reach spurious_interrupt + */ +3: j spurious_interrupt + +/* + * Vectors for interrupts generated by local devices + */ + .data +local_vector: PTR loc_no_irq + PTR loc_parallel + PTR loc_floppy + PTR loc_sound + PTR loc_video + PTR loc_ethernet + PTR loc_scsi + PTR loc_keyboard + PTR loc_mouse + PTR loc_serial1 + PTR loc_serial2 |