d04c56f73c
This implements a lazy strategy for disabling interrupts. This means that local_irq_disable() et al. just clear the 'interrupts are enabled' flag in the paca. If an interrupt comes along, the interrupt entry code notices that interrupts are supposed to be disabled, and clears the EE bit in SRR1, clears the 'interrupts are hard-enabled' flag in the paca, and returns. This means that interrupts only actually get disabled in the processor when an interrupt comes along. When interrupts are enabled by local_irq_enable() et al., the code sets the interrupts-enabled flag in the paca, and then checks whether interrupts got hard-disabled. If so, it also sets the EE bit in the MSR to hard-enable the interrupts. This has the potential to improve performance, and also makes it easier to make a kernel that can boot on iSeries and on other 64-bit machines, since this lazy-disable strategy is very similar to the soft-disable strategy that iSeries already uses. This version renames paca->proc_enabled to paca->soft_enabled, and changes a couple of soft-disables in the kexec code to hard-disables, which should fix the crash that Michael Ellerman saw. This doesn't yet use a reserved CR field for the soft_enabled and hard_enabled flags. This applies on top of Stephen Rothwell's patches to make it possible to build a combined iSeries/other kernel. Signed-off-by: Paul Mackerras <paulus@samba.org>
27 lines
759 B
ArmAsm
27 lines
759 B
ArmAsm
/*
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* This file contains miscellaneous low-level functions.
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* Copyright (C) 1995-2005 IBM Corp
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*
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* Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
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* and Paul Mackerras.
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* Adapted for iSeries by Mike Corrigan (mikejc@us.ibm.com)
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* PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <asm/processor.h>
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#include <asm/asm-offsets.h>
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#include <asm/ppc_asm.h>
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.text
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/* Handle pending interrupts in interrupt context */
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_GLOBAL(iseries_handle_interrupts)
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li r0,0x5555
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sc
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blr
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