patch-2.4.19 linux-2.4.19/arch/mips64/mips-boards/generic/mipsIRQ.S
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- Lines: 123
- Date:
Wed Dec 31 16:00:00 1969
- Orig file:
linux-2.4.18/arch/mips64/mips-boards/generic/mipsIRQ.S
- Orig date:
Sun Sep 9 10:43:02 2001
diff -urN linux-2.4.18/arch/mips64/mips-boards/generic/mipsIRQ.S linux-2.4.19/arch/mips64/mips-boards/generic/mipsIRQ.S
@@ -1,122 +0,0 @@
-/*
- * Carsten Langgaard, carstenl@mips.com
- * Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
- *
- * ########################################################################
- *
- * This program is free software; you can distribute it and/or modify it
- * under the terms of the GNU General Public License (Version 2) as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
- *
- * ########################################################################
- *
- * Interrupt exception dispatch code.
- *
- */
-#include <linux/config.h>
-
-#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 MIPS board look basically (barring software
- * IRQs which we don't use at all and all external interrupt sources are
- * combined together on hardware interrupt 0 (MIPS IRQ 2)) like:
- *
- * MIPS IRQ Source
- * -------- ------
- * 0 Software (ignored)
- * 1 Software (ignored)
- * 2 Combined hardware interrupt (hw0)
- * 3 Hardware (ignored)
- * 4 Hardware (ignored)
- * 5 Hardware (ignored)
- * 6 Hardware (ignored)
- * 7 R4k timer (what we use)
- *
- * We handle the IRQ according to _our_ priority which is:
- *
- * Highest ---- R4k Timer
- * Lowest ---- Combined hardware interrupt
- *
- * 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(mipsIRQ, 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 hw0 interrupt
-
- /* Wheee, a timer interrupt. */
- move a0, sp
- jal mips_timer_interrupt
- nop
-
- j ret_from_irq
- nop
-
-1:
- beq a0, zero, 1f
- nop
-
- /* Wheee, combined hardware level zero interrupt. */
-#if defined(CONFIG_MIPS_ATLAS)
- jal atlas_hw0_irqdispatch
-#elif defined(CONFIG_MIPS_MALTA)
- jal malta_hw0_irqdispatch
-#else
-#error "MIPS board not supported\n"
-#endif
- move a0, sp # delay slot
-
- j ret_from_irq
- nop # delay slot
-
-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.
- */
- move a1,s0
- PRINT("Got interrupt: c0_cause = %08x\n")
- mfc0 a1, CP0_EPC
- PRINT("c0_epc = %08x\n")
-
- j ret_from_irq
- nop
- END(mipsIRQ)
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