patch-2.4.19 linux-2.4.19/arch/mips/sgi/kernel/indyIRQ.S
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- Lines: 127
- Date:
Wed Dec 31 16:00:00 1969
- Orig file:
linux-2.4.18/arch/mips/sgi/kernel/indyIRQ.S
- Orig date:
Sun Jul 9 22:18:15 2000
diff -urN linux-2.4.18/arch/mips/sgi/kernel/indyIRQ.S linux-2.4.19/arch/mips/sgi/kernel/indyIRQ.S
@@ -1,126 +0,0 @@
-/*
- * indyIRQ.S: Interrupt exception dispatch code for FullHouse and
- * Guiness.
- *
- * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
- */
-
-#include <asm/asm.h>
-#include <asm/mipsregs.h>
-#include <asm/regdef.h>
-#include <asm/stackframe.h>
-
- /* 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 INDY look basically (barring
- * software IRQs which we don't use at all) like:
- *
- * MIPS IRQ Source
- * -------- ------
- * 0 Software (ignored)
- * 1 Software (ignored)
- * 2 Local IRQ level zero
- * 3 Local IRQ level one
- * 4 8254 Timer zero
- * 5 8254 Timer one
- * 6 Bus Error
- * 7 R4k timer (what we use)
- *
- * We handle the IRQ according to _our_ priority which is:
- *
- * Highest ---- R4k Timer
- * Local IRQ zero
- * Local IRQ one
- * Bus Error
- * 8254 Timer zero
- * Lowest ---- 8254 Timer one
- *
- * then we just return, if multiple IRQs are pending then
- * we will just take another exception, big deal.
- */
-
- .text
- .set noreorder
- .set noat
- .align 5
- NESTED(indyIRQ, PT_SIZE, sp)
- SAVE_ALL
- CLI
- .set at
- mfc0 s0, CP0_CAUSE # get irq mask
-
- /* First we check for r4k counter/timer IRQ. */
- andi a0, s0, CAUSEF_IP7
- beq a0, zero, 1f
- andi a0, s0, CAUSEF_IP2 # delay slot, check local level zero
-
- /* Wheee, a timer interrupt. */
- move a0, sp
- jal indy_r4k_timer_interrupt
- nop # delay slot
-
- j ret_from_irq
- nop # delay slot
-
-1:
- beq a0, zero, 1f
- andi a0, s0, CAUSEF_IP3 # delay slot, check local level one
-
- /* Wheee, local level zero interrupt. */
- jal indy_local0_irqdispatch
- move a0, sp # delay slot
-
- j ret_from_irq
- nop # delay slot
-
-1:
- beq a0, zero, 1f
- andi a0, s0, CAUSEF_IP6 # delay slot, check bus error
-
- /* Wheee, local level one interrupt. */
- move a0, sp
- jal indy_local1_irqdispatch
- nop
-
- j ret_from_irq
- nop
-
-1:
- beq a0, zero, 1f
- nop
-
- /* Wheee, an asynchronous bus error... */
- move a0, sp
- jal indy_buserror_irq
- nop
-
- j ret_from_irq
- nop
-
-1:
- /* Here by mistake? This is possible, what can happen
- * is that by the time we take the exception the IRQ
- * pin goes low, so just leave if this is the case.
- */
- andi a0, s0, (CAUSEF_IP4 | CAUSEF_IP5)
- beq a0, zero, 1f
-
- /* Must be one of the 8254 timers... */
- move a0, sp
- jal indy_8254timer_irq
- nop
-1:
- j ret_from_irq
- nop
- END(indyIRQ)
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