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freebsd-dev/sys/i386/isa/apic_vector.s
Peter Wemm cc66ebe2a9 Commit a partial lazy thread switch mechanism for i386. it isn't as lazy 
as it could be and can do with some more cleanup.  Currently its under
options LAZY_SWITCH.  What this does is avoid %cr3 reloads for short
context switches that do not involve another user process.  ie: we can
take an interrupt, switch to a kthread and return to the user without
explicitly flushing the tlb.  However, this isn't as exciting as it could
be, the interrupt overhead is still high and too much blocks on Giant
still.  There are some debug sysctls, for stats and for an on/off switch.

The main problem with doing this has been "what if the process that you're
running on exits while we're borrowing its address space?" - in this case
we use an IPI to give it a kick when we're about to reclaim the pmap.

Its not compiled in unless you add the LAZY_SWITCH option.  I want to fix a
few more things and get some more feedback before turning it on by default.

This is NOT a replacement for Bosko's lazy interrupt stuff.  This was more
meant for the kthread case, while his was for interrupts.  Mine helps a
little for interrupts, but his helps a lot more.

The stats are enabled with options SWTCH_OPTIM_STATS - this has been a
pseudo-option for years, I just added a bunch of stuff to it.

One non-trivial change was to select a new thread before calling
cpu_switch() in the first place.  This allows us to catch the silly
case of doing a cpu_switch() to the current process.  This happens
uncomfortably often.  This simplifies a bit of the asm code in cpu_switch
(no longer have to call choosethread() in the middle).  This has been
implemented on i386 and (thanks to jake) sparc64.  The others will come
soon.  This is actually seperate to the lazy switch stuff.

Glanced at by:  jake, jhb
2003-04-02 23:53:30 +00:00

681 lines
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/*
* from: vector.s, 386BSD 0.1 unknown origin
* $FreeBSD$
*/
#include "opt_swtch.h"
#include <machine/apic.h>
#include <machine/smp.h>
/* convert an absolute IRQ# into a bitmask */
#define IRQ_BIT(irq_num) (1 << (irq_num))
/* make an index into the IO APIC from the IRQ# */
#define REDTBL_IDX(irq_num) (0x10 + ((irq_num) * 2))
/*
*
*/
#define PUSH_FRAME \
pushl $0 ; /* dummy error code */ \
pushl $0 ; /* dummy trap type */ \
pushal ; /* 8 ints */ \
pushl %ds ; /* save data and extra segments ... */ \
pushl %es ; \
pushl %fs
#define PUSH_DUMMY \
pushfl ; /* eflags */ \
pushl %cs ; /* cs */ \
pushl 12(%esp) ; /* original caller eip */ \
pushl $0 ; /* dummy error code */ \
pushl $0 ; /* dummy trap type */ \
subl $11*4,%esp ;
#define POP_FRAME \
popl %fs ; \
popl %es ; \
popl %ds ; \
popal ; \
addl $4+4,%esp
#define POP_DUMMY \
addl $16*4,%esp
#define IOAPICADDR(irq_num) CNAME(int_to_apicintpin) + 16 * (irq_num) + 8
#define REDIRIDX(irq_num) CNAME(int_to_apicintpin) + 16 * (irq_num) + 12
#define MASK_IRQ(irq_num) \
ICU_LOCK ; /* into critical reg */ \
testl $IRQ_BIT(irq_num), apic_imen ; \
jne 7f ; /* masked, don't mask */ \
orl $IRQ_BIT(irq_num), apic_imen ; /* set the mask bit */ \
movl IOAPICADDR(irq_num), %ecx ; /* ioapic addr */ \
movl REDIRIDX(irq_num), %eax ; /* get the index */ \
movl %eax, (%ecx) ; /* write the index */ \
movl IOAPIC_WINDOW(%ecx), %eax ; /* current value */ \
orl $IOART_INTMASK, %eax ; /* set the mask */ \
movl %eax, IOAPIC_WINDOW(%ecx) ; /* new value */ \
7: ; /* already masked */ \
ICU_UNLOCK
/*
* Test to see whether we are handling an edge or level triggered INT.
* Level-triggered INTs must still be masked as we don't clear the source,
* and the EOI cycle would cause redundant INTs to occur.
*/
#define MASK_LEVEL_IRQ(irq_num) \
testl $IRQ_BIT(irq_num), apic_pin_trigger ; \
jz 9f ; /* edge, don't mask */ \
MASK_IRQ(irq_num) ; \
9:
#ifdef APIC_INTR_REORDER
#define EOI_IRQ(irq_num) \
movl apic_isrbit_location + 8 * (irq_num), %eax ; \
movl (%eax), %eax ; \
testl apic_isrbit_location + 4 + 8 * (irq_num), %eax ; \
jz 9f ; /* not active */ \
movl $0, lapic+LA_EOI ; \
9:
#else
#define EOI_IRQ(irq_num) \
testl $IRQ_BIT(irq_num), lapic+LA_ISR1; \
jz 9f ; /* not active */ \
movl $0, lapic+LA_EOI; \
9:
#endif
/*
* Test to see if the source is currently masked, clear if so.
*/
#define UNMASK_IRQ(irq_num) \
ICU_LOCK ; /* into critical reg */ \
testl $IRQ_BIT(irq_num), apic_imen ; \
je 7f ; /* bit clear, not masked */ \
andl $~IRQ_BIT(irq_num), apic_imen ;/* clear mask bit */ \
movl IOAPICADDR(irq_num), %ecx ; /* ioapic addr */ \
movl REDIRIDX(irq_num), %eax ; /* get the index */ \
movl %eax, (%ecx) ; /* write the index */ \
movl IOAPIC_WINDOW(%ecx), %eax ; /* current value */ \
andl $~IOART_INTMASK, %eax ; /* clear the mask */ \
movl %eax, IOAPIC_WINDOW(%ecx) ; /* new value */ \
7: ; /* already unmasked */ \
ICU_UNLOCK
/*
* Test to see whether we are handling an edge or level triggered INT.
* Level-triggered INTs have to be unmasked.
*/
#define UNMASK_LEVEL_IRQ(irq_num) \
testl $IRQ_BIT(irq_num), apic_pin_trigger ; \
jz 9f ; /* edge, don't unmask */ \
UNMASK_IRQ(irq_num) ; \
9:
/*
* Macros for interrupt entry, call to handler, and exit.
*/
#define FAST_INTR(irq_num, vec_name) \
.text ; \
SUPERALIGN_TEXT ; \
IDTVEC(vec_name) ; \
PUSH_FRAME ; \
movl $KDSEL,%eax ; \
mov %ax,%ds ; \
mov %ax,%es ; \
movl $KPSEL,%eax ; \
mov %ax,%fs ; \
FAKE_MCOUNT(13*4(%esp)) ; \
movl PCPU(CURTHREAD),%ebx ; \
cmpl $0,TD_CRITNEST(%ebx) ; \
je 1f ; \
; \
movl $1,PCPU(INT_PENDING) ; \
orl $IRQ_BIT(irq_num),PCPU(FPENDING) ; \
MASK_LEVEL_IRQ(irq_num) ; \
movl $0, lapic+LA_EOI ; \
jmp 10f ; \
1: ; \
incl TD_CRITNEST(%ebx) ; \
incl TD_INTR_NESTING_LEVEL(%ebx) ; \
pushl intr_unit + (irq_num) * 4 ; \
call *intr_handler + (irq_num) * 4 ; /* do the work ASAP */ \
addl $4, %esp ; \
movl $0, lapic+LA_EOI ; \
lock ; \
incl cnt+V_INTR ; /* book-keeping can wait */ \
movl intr_countp + (irq_num) * 4, %eax ; \
lock ; \
incl (%eax) ; \
decl TD_CRITNEST(%ebx) ; \
cmpl $0,PCPU(INT_PENDING) ; \
je 2f ; \
; \
call i386_unpend ; \
2: ; \
decl TD_INTR_NESTING_LEVEL(%ebx) ; \
10: ; \
MEXITCOUNT ; \
jmp doreti
/*
* Restart a fast interrupt that was held up by a critical section.
* This routine is called from unpend(). unpend() ensures we are
* in a critical section and deals with the interrupt nesting level
* for us. If we previously masked the irq, we have to unmask it.
*
* We have a choice. We can regenerate the irq using the 'int'
* instruction or we can create a dummy frame and call the interrupt
* handler directly. I've chosen to use the dummy-frame method.
*/
#define FAST_UNPEND(irq_num, vec_name) \
.text ; \
SUPERALIGN_TEXT ; \
IDTVEC(vec_name) ; \
; \
pushl %ebp ; \
movl %esp, %ebp ; \
PUSH_DUMMY ; \
pushl intr_unit + (irq_num) * 4 ; \
call *intr_handler + (irq_num) * 4 ; /* do the work ASAP */ \
addl $4, %esp ; \
lock ; \
incl cnt+V_INTR ; /* book-keeping can wait */ \
movl intr_countp + (irq_num) * 4, %eax ; \
lock ; \
incl (%eax) ; \
UNMASK_LEVEL_IRQ(irq_num) ; \
POP_DUMMY ; \
popl %ebp ; \
ret ; \
/*
* Slow, threaded interrupts.
*
* XXX Most of the parameters here are obsolete. Fix this when we're
* done.
* XXX we really shouldn't return via doreti if we just schedule the
* interrupt handler and don't run anything. We could just do an
* iret. FIXME.
*/
#define INTR(irq_num, vec_name, maybe_extra_ipending) \
.text ; \
SUPERALIGN_TEXT ; \
/* _XintrNN: entry point used by IDT/HWIs via _vec[]. */ \
IDTVEC(vec_name) ; \
PUSH_FRAME ; \
movl $KDSEL, %eax ; /* reload with kernel's data segment */ \
mov %ax, %ds ; \
mov %ax, %es ; \
movl $KPSEL, %eax ; \
mov %ax, %fs ; \
; \
maybe_extra_ipending ; \
; \
MASK_LEVEL_IRQ(irq_num) ; \
EOI_IRQ(irq_num) ; \
; \
movl PCPU(CURTHREAD),%ebx ; \
cmpl $0,TD_CRITNEST(%ebx) ; \
je 1f ; \
movl $1,PCPU(INT_PENDING) ; \
orl $IRQ_BIT(irq_num),PCPU(IPENDING) ; \
jmp 10f ; \
1: ; \
incl TD_INTR_NESTING_LEVEL(%ebx) ; \
; \
FAKE_MCOUNT(13*4(%esp)) ; /* XXX avoid dbl cnt */ \
cmpl $0,PCPU(INT_PENDING) ; \
je 9f ; \
call i386_unpend ; \
9: ; \
pushl $irq_num; /* pass the IRQ */ \
call sched_ithd ; \
addl $4, %esp ; /* discard the parameter */ \
; \
decl TD_INTR_NESTING_LEVEL(%ebx) ; \
10: ; \
MEXITCOUNT ; \
jmp doreti
/*
* Handle "spurious INTerrupts".
* Notes:
* This is different than the "spurious INTerrupt" generated by an
* 8259 PIC for missing INTs. See the APIC documentation for details.
* This routine should NOT do an 'EOI' cycle.
*/
.text
SUPERALIGN_TEXT
.globl Xspuriousint
Xspuriousint:
/* No EOI cycle used here */
iret
/*
* Global address space TLB shootdown.
*/
.text
SUPERALIGN_TEXT
.globl Xinvltlb
Xinvltlb:
pushl %eax
pushl %ds
movl $KDSEL, %eax /* Kernel data selector */
mov %ax, %ds
#ifdef COUNT_XINVLTLB_HITS
pushl %fs
movl $KPSEL, %eax /* Private space selector */
mov %ax, %fs
movl PCPU(CPUID), %eax
popl %fs
incl xhits_gbl(,%eax,4)
#endif /* COUNT_XINVLTLB_HITS */
movl %cr3, %eax /* invalidate the TLB */
movl %eax, %cr3
movl $0, lapic+LA_EOI /* End Of Interrupt to APIC */
lock
incl smp_tlb_wait
popl %ds
popl %eax
iret
/*
* Single page TLB shootdown
*/
.text
SUPERALIGN_TEXT
.globl Xinvlpg
Xinvlpg:
pushl %eax
pushl %ds
movl $KDSEL, %eax /* Kernel data selector */
mov %ax, %ds
#ifdef COUNT_XINVLTLB_HITS
pushl %fs
movl $KPSEL, %eax /* Private space selector */
mov %ax, %fs
movl PCPU(CPUID), %eax
popl %fs
incl xhits_pg(,%eax,4)
#endif /* COUNT_XINVLTLB_HITS */
movl smp_tlb_addr1, %eax
invlpg (%eax) /* invalidate single page */
movl $0, lapic+LA_EOI /* End Of Interrupt to APIC */
lock
incl smp_tlb_wait
popl %ds
popl %eax
iret
/*
* Page range TLB shootdown.
*/
.text
SUPERALIGN_TEXT
.globl Xinvlrng
Xinvlrng:
pushl %eax
pushl %edx
pushl %ds
movl $KDSEL, %eax /* Kernel data selector */
mov %ax, %ds
#ifdef COUNT_XINVLTLB_HITS
pushl %fs
movl $KPSEL, %eax /* Private space selector */
mov %ax, %fs
movl PCPU(CPUID), %eax
popl %fs
incl xhits_rng(,%eax,4)
#endif /* COUNT_XINVLTLB_HITS */
movl smp_tlb_addr1, %edx
movl smp_tlb_addr2, %eax
1: invlpg (%edx) /* invalidate single page */
addl $PAGE_SIZE, %edx
cmpl %eax, %edx
jb 1b
movl $0, lapic+LA_EOI /* End Of Interrupt to APIC */
lock
incl smp_tlb_wait
popl %ds
popl %edx
popl %eax
iret
/*
* Forward hardclock to another CPU. Pushes a clockframe and calls
* forwarded_hardclock().
*/
.text
SUPERALIGN_TEXT
.globl Xhardclock
Xhardclock:
PUSH_FRAME
movl $KDSEL, %eax /* reload with kernel's data segment */
mov %ax, %ds
mov %ax, %es
movl $KPSEL, %eax
mov %ax, %fs
movl $0, lapic+LA_EOI /* End Of Interrupt to APIC */
movl PCPU(CURTHREAD),%ebx
cmpl $0,TD_CRITNEST(%ebx)
je 1f
movl $1,PCPU(INT_PENDING)
orl $1,PCPU(SPENDING);
jmp 10f
1:
incl TD_INTR_NESTING_LEVEL(%ebx)
pushl $0 /* XXX convert trapframe to clockframe */
call forwarded_hardclock
addl $4, %esp /* XXX convert clockframe to trapframe */
decl TD_INTR_NESTING_LEVEL(%ebx)
10:
MEXITCOUNT
jmp doreti
/*
* Forward statclock to another CPU. Pushes a clockframe and calls
* forwarded_statclock().
*/
.text
SUPERALIGN_TEXT
.globl Xstatclock
Xstatclock:
PUSH_FRAME
movl $KDSEL, %eax /* reload with kernel's data segment */
mov %ax, %ds
mov %ax, %es
movl $KPSEL, %eax
mov %ax, %fs
movl $0, lapic+LA_EOI /* End Of Interrupt to APIC */
FAKE_MCOUNT(13*4(%esp))
movl PCPU(CURTHREAD),%ebx
cmpl $0,TD_CRITNEST(%ebx)
je 1f
movl $1,PCPU(INT_PENDING)
orl $2,PCPU(SPENDING);
jmp 10f
1:
incl TD_INTR_NESTING_LEVEL(%ebx)
pushl $0 /* XXX convert trapframe to clockframe */
call forwarded_statclock
addl $4, %esp /* XXX convert clockframe to trapframe */
decl TD_INTR_NESTING_LEVEL(%ebx)
10:
MEXITCOUNT
jmp doreti
/*
* Executed by a CPU when it receives an Xcpuast IPI from another CPU,
*
* The other CPU has already executed aston() or need_resched() on our
* current process, so we simply need to ack the interrupt and return
* via doreti to run ast().
*/
.text
SUPERALIGN_TEXT
.globl Xcpuast
Xcpuast:
PUSH_FRAME
movl $KDSEL, %eax
mov %ax, %ds /* use KERNEL data segment */
mov %ax, %es
movl $KPSEL, %eax
mov %ax, %fs
movl $0, lapic+LA_EOI /* End Of Interrupt to APIC */
FAKE_MCOUNT(13*4(%esp))
MEXITCOUNT
jmp doreti
/*
* Executed by a CPU when it receives an Xcpustop IPI from another CPU,
*
* - Signals its receipt.
* - Waits for permission to restart.
* - Signals its restart.
*/
.text
SUPERALIGN_TEXT
.globl Xcpustop
Xcpustop:
pushl %ebp
movl %esp, %ebp
pushl %eax
pushl %ecx
pushl %edx
pushl %ds /* save current data segment */
pushl %fs
movl $KDSEL, %eax
mov %ax, %ds /* use KERNEL data segment */
movl $KPSEL, %eax
mov %ax, %fs
movl $0, lapic+LA_EOI /* End Of Interrupt to APIC */
movl PCPU(CPUID), %eax
imull $PCB_SIZE, %eax
leal CNAME(stoppcbs)(%eax), %eax
pushl %eax
call CNAME(savectx) /* Save process context */
addl $4, %esp
movl PCPU(CPUID), %eax
lock
btsl %eax, CNAME(stopped_cpus) /* stopped_cpus |= (1<<id) */
1:
btl %eax, CNAME(started_cpus) /* while (!(started_cpus & (1<<id))) */
jnc 1b
lock
btrl %eax, CNAME(started_cpus) /* started_cpus &= ~(1<<id) */
lock
btrl %eax, CNAME(stopped_cpus) /* stopped_cpus &= ~(1<<id) */
test %eax, %eax
jnz 2f
movl CNAME(cpustop_restartfunc), %eax
test %eax, %eax
jz 2f
movl $0, CNAME(cpustop_restartfunc) /* One-shot */
call *%eax
2:
popl %fs
popl %ds /* restore previous data segment */
popl %edx
popl %ecx
popl %eax
movl %ebp, %esp
popl %ebp
iret
MCOUNT_LABEL(bintr)
FAST_INTR(0,fastintr0)
FAST_INTR(1,fastintr1)
FAST_INTR(2,fastintr2)
FAST_INTR(3,fastintr3)
FAST_INTR(4,fastintr4)
FAST_INTR(5,fastintr5)
FAST_INTR(6,fastintr6)
FAST_INTR(7,fastintr7)
FAST_INTR(8,fastintr8)
FAST_INTR(9,fastintr9)
FAST_INTR(10,fastintr10)
FAST_INTR(11,fastintr11)
FAST_INTR(12,fastintr12)
FAST_INTR(13,fastintr13)
FAST_INTR(14,fastintr14)
FAST_INTR(15,fastintr15)
FAST_INTR(16,fastintr16)
FAST_INTR(17,fastintr17)
FAST_INTR(18,fastintr18)
FAST_INTR(19,fastintr19)
FAST_INTR(20,fastintr20)
FAST_INTR(21,fastintr21)
FAST_INTR(22,fastintr22)
FAST_INTR(23,fastintr23)
FAST_INTR(24,fastintr24)
FAST_INTR(25,fastintr25)
FAST_INTR(26,fastintr26)
FAST_INTR(27,fastintr27)
FAST_INTR(28,fastintr28)
FAST_INTR(29,fastintr29)
FAST_INTR(30,fastintr30)
FAST_INTR(31,fastintr31)
#define CLKINTR_PENDING movl $1,CNAME(clkintr_pending)
/* Threaded interrupts */
INTR(0,intr0, CLKINTR_PENDING)
INTR(1,intr1,)
INTR(2,intr2,)
INTR(3,intr3,)
INTR(4,intr4,)
INTR(5,intr5,)
INTR(6,intr6,)
INTR(7,intr7,)
INTR(8,intr8,)
INTR(9,intr9,)
INTR(10,intr10,)
INTR(11,intr11,)
INTR(12,intr12,)
INTR(13,intr13,)
INTR(14,intr14,)
INTR(15,intr15,)
INTR(16,intr16,)
INTR(17,intr17,)
INTR(18,intr18,)
INTR(19,intr19,)
INTR(20,intr20,)
INTR(21,intr21,)
INTR(22,intr22,)
INTR(23,intr23,)
INTR(24,intr24,)
INTR(25,intr25,)
INTR(26,intr26,)
INTR(27,intr27,)
INTR(28,intr28,)
INTR(29,intr29,)
INTR(30,intr30,)
INTR(31,intr31,)
FAST_UNPEND(0,fastunpend0)
FAST_UNPEND(1,fastunpend1)
FAST_UNPEND(2,fastunpend2)
FAST_UNPEND(3,fastunpend3)
FAST_UNPEND(4,fastunpend4)
FAST_UNPEND(5,fastunpend5)
FAST_UNPEND(6,fastunpend6)
FAST_UNPEND(7,fastunpend7)
FAST_UNPEND(8,fastunpend8)
FAST_UNPEND(9,fastunpend9)
FAST_UNPEND(10,fastunpend10)
FAST_UNPEND(11,fastunpend11)
FAST_UNPEND(12,fastunpend12)
FAST_UNPEND(13,fastunpend13)
FAST_UNPEND(14,fastunpend14)
FAST_UNPEND(15,fastunpend15)
FAST_UNPEND(16,fastunpend16)
FAST_UNPEND(17,fastunpend17)
FAST_UNPEND(18,fastunpend18)
FAST_UNPEND(19,fastunpend19)
FAST_UNPEND(20,fastunpend20)
FAST_UNPEND(21,fastunpend21)
FAST_UNPEND(22,fastunpend22)
FAST_UNPEND(23,fastunpend23)
FAST_UNPEND(24,fastunpend24)
FAST_UNPEND(25,fastunpend25)
FAST_UNPEND(26,fastunpend26)
FAST_UNPEND(27,fastunpend27)
FAST_UNPEND(28,fastunpend28)
FAST_UNPEND(29,fastunpend29)
FAST_UNPEND(30,fastunpend30)
FAST_UNPEND(31,fastunpend31)
MCOUNT_LABEL(eintr)
/*
* Executed by a CPU when it receives a RENDEZVOUS IPI from another CPU.
*
* - Calls the generic rendezvous action function.
*/
.text
SUPERALIGN_TEXT
.globl Xrendezvous
Xrendezvous:
PUSH_FRAME
movl $KDSEL, %eax
mov %ax, %ds /* use KERNEL data segment */
mov %ax, %es
movl $KPSEL, %eax
mov %ax, %fs
call smp_rendezvous_action
movl $0, lapic+LA_EOI /* End Of Interrupt to APIC */
POP_FRAME
iret
#ifdef LAZY_SWITCH
/*
* Clean up when we lose out on the lazy context switch optimization.
* ie: when we are about to release a PTD but a cpu is still borrowing it.
*/
SUPERALIGN_TEXT
.globl Xlazypmap
Xlazypmap:
PUSH_FRAME
movl $KDSEL, %eax
mov %ax, %ds /* use KERNEL data segment */
mov %ax, %es
movl $KPSEL, %eax
mov %ax, %fs
call pmap_lazyfix_action
movl $0, lapic+LA_EOI /* End Of Interrupt to APIC */
POP_FRAME
iret
#endif
.data
.globl apic_pin_trigger
apic_pin_trigger:
.long 0
.text
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