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/*
* from: vector.s, 386BSD 0.1 unknown origin
* $Id: vector.s,v 1.2 1997/05/24 17:05:26 smp Exp smp $
*/
/*
* modified for PC98 by Kakefuda
*/
#include "opt_auto_eoi.h"
#include <i386/isa/icu.h>
#ifdef PC98
#include <pc98/pc98/pc98.h>
#else
#include <i386/isa/isa.h>
#endif
#ifdef FAST_INTR_HANDLER_USES_ES
#define ACTUALLY_PUSHED 1
#define MAYBE_MOVW_AX_ES movl %ax,%es
#define MAYBE_POPL_ES popl %es
#define MAYBE_PUSHL_ES pushl %es
#else
/*
* We can usually skip loading %es for fastintr handlers. %es should
* only be used for string instructions, and fastintr handlers shouldn't
* do anything slow enough to justify using a string instruction.
*/
#define ACTUALLY_PUSHED 0
#define MAYBE_MOVW_AX_ES
#define MAYBE_POPL_ES
#define MAYBE_PUSHL_ES
#endif
.data
ALIGN_DATA
.globl _intr_nesting_level
_intr_nesting_level:
.byte 0
.space 3
.text
/*
* Macros for interrupt interrupt entry, call to handler, and exit.
*
* XXX - the interrupt frame is set up to look like a trap frame. This is
* usually a waste of time. The only interrupt handlers that want a frame
* are the clock handler (it wants a clock frame), the npx handler (it's
* easier to do right all in assembler). The interrupt return routine
* needs a trap frame for rare AST's (it could easily convert the frame).
* The direct costs of setting up a trap frame are two pushl's (error
* code and trap number), an addl to get rid of these, and pushing and
* popping the call-saved regs %esi, %edi and %ebp twice, The indirect
* costs are making the driver interface nonuniform so unpending of
* interrupts is more complicated and slower (call_driver(unit) would
* be easier than ensuring an interrupt frame for all handlers. Finally,
* there are some struct copies in the npx handler and maybe in the clock
* handler that could be avoided by working more with pointers to frames
* instead of frames.
*
* XXX - should we do a cld on every system entry to avoid the requirement
* for scattered cld's?
*
* Coding notes for *.s:
*
* If possible, avoid operations that involve an operand size override.
* Word-sized operations might be smaller, but the operand size override
* makes them slower on on 486's and no faster on 386's unless perhaps
* the instruction pipeline is depleted. E.g.,
*
* Use movl to seg regs instead of the equivalent but more descriptive
* movw - gas generates an irelevant (slower) operand size override.
*
* Use movl to ordinary regs in preference to movw and especially
* in preference to movz[bw]l. Use unsigned (long) variables with the
* top bits clear instead of unsigned short variables to provide more
* opportunities for movl.
*
* If possible, use byte-sized operations. They are smaller and no slower.
*
* Use (%reg) instead of 0(%reg) - gas generates larger code for the latter.
*
* If the interrupt frame is made more flexible, INTR can push %eax first
* and decide the ipending case with less overhead, e.g., by avoiding
* loading segregs.
*/
#ifdef APIC_IO
#include "i386/isa/apic_vector.s"
#else
#include "i386/isa/icu_vector.s"
#endif /* APIC_IO */
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