freebsd-skq/sys/i386/isa/vector.s
1993-12-20 15:08:33 +00:00

369 lines
11 KiB
ArmAsm

/*
* from: vector.s, 386BSD 0.1 unknown origin
* $Id: vector.s,v 1.4 1993/10/16 13:46:28 rgrimes Exp $
*/
#include "i386/isa/icu.h"
#include "i386/isa/isa.h"
#include "vector.h"
#define ICU_EOI 0x20 /* XXX - define elsewhere */
#define IRQ_BIT(irq_num) (1 << ((irq_num) % 8))
#define IRQ_BYTE(irq_num) ((irq_num) / 8)
#define ENABLE_ICU1 \
movb $ICU_EOI,%al ; /* as soon as possible send EOI ... */ \
FASTER_NOP ; /* ... ASAP ... */ \
outb %al,$IO_ICU1 /* ... to clear in service bit */
#ifdef AUTO_EOI_1
#undef ENABLE_ICU1 /* we now use auto-EOI to reduce i/o */
#define ENABLE_ICU1
#endif
#define ENABLE_ICU1_AND_2 \
movb $ICU_EOI,%al ; /* as above */ \
FASTER_NOP ; \
outb %al,$IO_ICU2 ; /* but do second icu first */ \
FASTER_NOP ; \
outb %al,$IO_ICU1 /* then first icu */
#ifdef AUTO_EOI_2
#undef ENABLE_ICU1_AND_2 /* data sheet says no auto-EOI on slave ... */
#define ENABLE_ICU1_AND_2 /* ... but it works */
#endif
/*
* 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.
*/
#define FAST_INTR(unit, irq_num, id_num, handler, enable_icus) \
pushl %eax ; /* save only call-used registers */ \
pushl %ecx ; \
pushl %edx ; \
pushl %ds ; \
/* pushl %es ; know compiler doesn't do string insns */ \
movl $KDSEL,%eax ; \
movl %ax,%ds ; \
/* movl %ax,%es ; */ \
SHOW_CLI ; /* although it interferes with "ASAP" */ \
pushl $unit ; \
call handler ; /* do the work ASAP */ \
enable_icus ; /* (re)enable ASAP (helps edge trigger?) */ \
addl $4,%esp ; \
incl _cnt+V_INTR ; /* book-keeping can wait */ \
COUNT_EVENT(_intrcnt_actv, id_num) ; \
SHOW_STI ; \
/* popl %es ; */ \
popl %ds ; \
popl %edx; \
popl %ecx; \
popl %eax; \
iret
#define INTR(unit, irq_num, id_num, mask, handler, icu, enable_icus, reg, stray) \
pushl $0 ; /* dummy error code */ \
pushl $T_ASTFLT ; \
pushal ; \
pushl %ds ; /* save our data and extra segments ... */ \
pushl %es ; \
movl $KDSEL,%eax ; /* ... and reload with kernel's own ... */ \
movl %ax,%ds ; /* ... early in case SHOW_A_LOT is on */ \
movl %ax,%es ; \
SHOW_CLI ; /* interrupt did an implicit cli */ \
movb _imen + IRQ_BYTE(irq_num),%al ; \
orb $IRQ_BIT(irq_num),%al ; \
movb %al,_imen + IRQ_BYTE(irq_num) ; \
SHOW_IMEN ; \
FASTER_NOP ; \
outb %al,$icu+1 ; \
enable_icus ; \
incl _cnt+V_INTR ; /* tally interrupts */ \
movl _cpl,%eax ; \
testb $IRQ_BIT(irq_num),%reg ; \
jne 2f ; \
1: ; \
COUNT_EVENT(_intrcnt_actv, id_num) ; \
movl _cpl,%eax ; \
pushl %eax ; \
pushl $unit ; \
orl mask,%eax ; \
movl %eax,_cpl ; \
SHOW_CPL ; \
SHOW_STI ; \
sti ; \
call handler ; \
movb _imen + IRQ_BYTE(irq_num),%al ; \
andb $~IRQ_BIT(irq_num),%al ; \
movb %al,_imen + IRQ_BYTE(irq_num) ; \
SHOW_IMEN ; \
FASTER_NOP ; \
outb %al,$icu+1 ; \
jmp doreti ; \
; \
ALIGN_TEXT ; \
2: ; \
COUNT_EVENT(_intrcnt_pend, id_num) ; \
movl $1b,%eax ; /* register resume address */ \
/* XXX - someday do it at attach time */ \
movl %eax,Vresume + (irq_num) * 4 ; \
orb $IRQ_BIT(irq_num),_ipending + IRQ_BYTE(irq_num) ; \
SHOW_IPENDING ; \
popl %es ; \
popl %ds ; \
popal ; \
addl $4+4,%esp ; \
iret
/*
* vector.h has defined a macro 'BUILD_VECTORS' containing a big list of info
* about vectors, including a submacro 'BUILD_VECTOR' that operates on the
* info about each vector. We redefine 'BUILD_VECTOR' to expand the info
* in different ways. Here we expand it to a list of interrupt handlers.
* This order is of course unimportant. Elsewhere we expand it to inline
* linear search code for which the order is a little more important and
* concatenating the code with no holes is very important.
*
* XXX - now there is BUILD_FAST_VECTOR as well as BUILD_VECTOR.
*
* The info consists of the following items for each vector:
*
* name (identifier): name of the vector; used to build labels
* unit (expression): unit number to call the device driver with
* irq_num (number): number of the IRQ to handled (0-15)
* id_num (number): uniq numeric id for handler (assigned by config)
* mask (blank-ident): priority mask used
* handler (blank-ident): interrupt handler to call
* icu_num (number): (1 + irq_num / 8) converted for label building
* icu_enables (number): 1 for icu_num == 1, 1_AND_2 for icu_num == 2
* reg (blank-ident): al for icu_num == 1, ah for icu_num == 2
*
* 'irq_num' is converted in several ways at config time to get around
* limitations in cpp. The macros have blanks after commas iff they would
* not mess up identifiers and numbers.
*/
#undef BUILD_FAST_VECTOR
#define BUILD_FAST_VECTOR(name, unit, irq_num, id_num, mask, handler, \
icu_num, icu_enables, reg) \
.globl handler ; \
.text ; \
.globl _V/**/name ; \
SUPERALIGN_TEXT ; \
_V/**/name: ; \
FAST_INTR(unit, irq_num, id_num, handler, ENABLE_ICU/**/icu_enables)
#undef BUILD_VECTOR
#define BUILD_VECTOR(name, unit, irq_num, id_num, mask, handler, \
icu_num, icu_enables, reg) \
.globl handler ; \
.text ; \
.globl _V/**/name ; \
SUPERALIGN_TEXT ; \
_V/**/name: ; \
INTR(unit,irq_num,id_num, mask, handler, IO_ICU/**/icu_num, \
ENABLE_ICU/**/icu_enables, reg,)
BUILD_VECTORS
/* hardware interrupt catcher (IDT 32 - 47) */
.globl _isa_strayintr
#define STRAYINTR(irq_num, icu_num, icu_enables, reg) \
IDTVEC(intr/**/irq_num) ; \
INTR(irq_num,irq_num,irq_num, _highmask, _isa_strayintr, \
IO_ICU/**/icu_num, ENABLE_ICU/**/icu_enables, reg,stray)
/*
* XXX - the mask (1 << 2) == IRQ_SLAVE will be generated for IRQ 2, instead
* of the mask IRQ2 (defined as IRQ9 == (1 << 9)). But IRQ 2 "can't happen".
* In fact, all stray interrupts "can't happen" except for bugs. The
* "stray" IRQ 7 is documented behaviour of the 8259. It happens when there
* is a glitch on any of its interrupt inputs. Does it really interrupt when
* IRQ 7 is masked?
*
* XXX - unpend doesn't work for these, it sends them to the real handler.
*
* XXX - the race bug during initialization may be because I changed the
* order of switching from the stray to the real interrupt handler to before
* enabling interrupts. The old order looked unsafe but maybe it is OK with
* the stray interrupt handler installed. But these handlers only reduce
* the window of vulnerability - it is still open at the end of
* isa_configure().
*
* XXX - many comments are stale.
*/
STRAYINTR(0,1,1, al)
STRAYINTR(1,1,1, al)
STRAYINTR(2,1,1, al)
STRAYINTR(3,1,1, al)
STRAYINTR(4,1,1, al)
STRAYINTR(5,1,1, al)
STRAYINTR(6,1,1, al)
STRAYINTR(8,2,1_AND_2, ah)
STRAYINTR(9,2,1_AND_2, ah)
STRAYINTR(10,2,1_AND_2, ah)
STRAYINTR(11,2,1_AND_2, ah)
STRAYINTR(12,2,1_AND_2, ah)
STRAYINTR(13,2,1_AND_2, ah)
STRAYINTR(14,2,1_AND_2, ah)
STRAYINTR(15,2,1_AND_2, ah)
IDTVEC(intrdefault)
STRAYINTR(7,1,1, al) /* XXX */
#if 0
INTRSTRAY(255, _highmask, 255) ; call _isa_strayintr ; INTREXIT2
#endif
/*
* These are the interrupt counters, I moved them here from icu.s so that
* they are with the name table. rgrimes
*
* There are now lots of counters, this has been redone to work with
* Bruce Evans intr-0.1 code, which I modified some more to make it all
* work with vmstat.
*/
.data
Vresume: .space 16 * 4 /* where to resume intr handler after unpend */
.globl _intrcnt
_intrcnt: /* used by vmstat to calc size of table */
.globl _intrcnt_bad7
_intrcnt_bad7: .space 4 /* glitches on irq 7 */
.globl _intrcnt_bad15
_intrcnt_bad15: .space 4 /* glitches on irq 15 */
.globl _intrcnt_stray
_intrcnt_stray: .space 4 /* total count of stray interrupts */
.globl _intrcnt_actv
_intrcnt_actv: .space NR_REAL_INT_HANDLERS * 4 /* active interrupts */
.globl _intrcnt_pend
_intrcnt_pend: .space NR_REAL_INT_HANDLERS * 4 /* pending interrupts */
.globl _eintrcnt
_eintrcnt: /* used by vmstat to calc size of table */
.globl _intrcnt_spl
_intrcnt_spl: .space 32 * 4 /* XXX 32 should not be hard coded ? */
.globl _intrcnt_show
_intrcnt_show: .space 8 * 4 /* XXX 16 should not be hard coded ? */
/*
* Build the interrupt name table for vmstat
*/
#undef BUILD_FAST_VECTOR
#define BUILD_FAST_VECTOR BUILD_VECTOR
#undef BUILD_VECTOR
#define BUILD_VECTOR(name, unit, irq_num, id_num, mask, handler, \
icu_num, icu_enables, reg) \
.ascii "name irq" ; \
.asciz "irq_num"
/*
* XXX - use the STRING and CONCAT macros from <sys/cdefs.h> to stringize
* and concatenate names above and elsewhere.
*/
.text
.globl _intrnames, _eintrnames
_intrnames:
BUILD_VECTOR(bad,,7,,,,,,)
BUILD_VECTOR(bad,,15,,,,,,)
BUILD_VECTOR(stray,,,,,,,,)
BUILD_VECTORS
#undef BUILD_FAST_VECTOR
#define BUILD_FAST_VECTOR BUILD_VECTOR
#undef BUILD_VECTOR
#define BUILD_VECTOR(name, unit, irq_num, id_num, mask, handler, \
icu_num, icu_enables, reg) \
.asciz "name pend"
BUILD_VECTORS
_eintrnames:
/*
* now the spl names
*/
.asciz "unpend_v"
.asciz "doreti"
.asciz "p0!ni"
.asciz "!p0!ni"
.asciz "p0ni"
.asciz "netisr_raw"
.asciz "netisr_ip"
.asciz "netisr_imp"
.asciz "netisr_ns"
.asciz "netisr_iso"
.asciz "softclock" /* 10 */
.asciz "trap"
.asciz "doreti_exit2"
.asciz "splbio"
.asciz "splclock"
.asciz "splhigh"
.asciz "splimp"
.asciz "splnet"
.asciz "splsoftclock"
.asciz "spltty"
.asciz "spl0" /* 20 */
.asciz "netisr_raw2"
.asciz "netisr_ip2"
.asciz "netisr_imp2"
.asciz "netisr_ns2"
.asciz "netisr_iso2"
.asciz "splx"
.asciz "splx!0"
.asciz "unpend_V"
.asciz "netisr_x25"
.asciz "netisr_hdlc"
.asciz "spl31"
/*
* now the mask names
*/
.asciz "cli"
.asciz "cpl"
.asciz "imen"
.asciz "ipending"
.asciz "sti"
.asciz "mask5" /* mask5-mask7 are spares */
.asciz "mask6"
.asciz "mask7"