diff options
Diffstat (limited to 'sys/i386/isa/ipl.s')
| -rw-r--r-- | sys/i386/isa/ipl.s | 119 |
1 files changed, 28 insertions, 91 deletions
diff --git a/sys/i386/isa/ipl.s b/sys/i386/isa/ipl.s index 7c1fca1..980257f 100644 --- a/sys/i386/isa/ipl.s +++ b/sys/i386/isa/ipl.s @@ -43,6 +43,10 @@ /* * AT/386 * Vector interrupt control section + * + * cpl - Current interrupt disable mask + * *_imask - Interrupt masks for various spl*() functions + * ipending - Pending interrupts (set when a masked interrupt occurs) */ .data @@ -67,9 +71,6 @@ _softnet_imask: .long SWI_NET_MASK .globl _softtty_imask _softtty_imask: .long SWI_TTY_MASK - .globl _astpending -_astpending: .long 0 - /* pending interrupts blocked by splxxx() */ .globl _ipending _ipending: .long 0 @@ -91,29 +92,12 @@ _netisrs: .text -#ifdef SMP -#ifdef notnow -#define TEST_CIL \ - cmpl $0x0100, _cil ; \ - jne 1f ; \ - cmpl $0, _inside_intr ; \ - jne 1f ; \ - int $3 ; \ -1: -#else -#define TEST_CIL -#endif -#endif - /* * Handle return from interrupts, traps and syscalls. */ SUPERALIGN_TEXT .type _doreti,@function _doreti: -#ifdef SMP - TEST_CIL -#endif FAKE_MCOUNT(_bintr) /* init "from" _bintr -> _doreti */ addl $4,%esp /* discard unit number */ popl %eax /* cpl or cml to restore */ @@ -128,32 +112,17 @@ doreti_next: * handlers is limited by the number of bits in cpl). */ #ifdef SMP - TEST_CIL cli /* early to prevent INT deadlock */ - pushl %eax /* preserve cpl while getting lock */ - ICPL_LOCK - popl %eax doreti_next2: #endif movl %eax,%ecx -#ifdef CPL_AND_CML - orl _cpl, %ecx /* add cpl to cml */ -#endif notl %ecx /* set bit = unmasked level */ #ifndef SMP cli #endif andl _ipending,%ecx /* set bit = unmasked pending INT */ jne doreti_unpend -#ifdef SMP - TEST_CIL -#endif -#ifdef CPL_AND_CML - movl %eax, _cml -#else movl %eax,_cpl -#endif - FAST_ICPL_UNLOCK /* preserves %eax */ MPLOCKED decb _intr_nesting_level /* Check for ASTs that can be handled now. */ @@ -166,19 +135,27 @@ doreti_next2: cmpl $1,_in_vm86call jne doreti_ast + /* + * doreti_exit - release MP lock, pop registers, iret. + * + * Note that the syscall trap shotcuts to doreti_syscall_ret. + * The segment register pop is a special case, since it may + * fault if (for example) a sigreturn specifies bad segment + * registers. The fault is handled in trap.c + */ + doreti_exit: MEXITCOUNT #ifdef SMP -#ifdef INTR_SIMPLELOCK -#error code needed here to decide which lock to release, INTR or giant -#endif /* release the kernel lock */ movl $_mp_lock, %edx /* GIANT_LOCK */ call _MPrellock_edx #endif /* SMP */ .globl doreti_popl_fs + .globl doreti_syscall_ret +doreti_syscall_ret: doreti_popl_fs: popl %fs .globl doreti_popl_es @@ -215,22 +192,13 @@ doreti_popl_fs_fault: doreti_unpend: /* * Enabling interrupts is safe because we haven't restored cpl yet. - * The locking from the "btrl" test is probably no longer necessary. - * We won't miss any new pending interrupts because we will check - * for them again. + * %ecx contains the next probable ready interrupt (~cpl & ipending) */ #ifdef SMP - TEST_CIL - /* we enter with cpl locked */ - bsfl %ecx, %ecx /* slow, but not worth optimizing */ + bsfl %ecx, %ecx /* locate the next dispatchable int */ lock - btrl %ecx, _ipending + btrl %ecx, _ipending /* is it really still pending? */ jnc doreti_next2 /* some intr cleared memory copy */ - cmpl $NHWI, %ecx - jae 1f - btsl %ecx, _cil -1: - FAST_ICPL_UNLOCK /* preserves %eax */ sti /* late to prevent INT deadlock */ #else sti @@ -238,8 +206,9 @@ doreti_unpend: btrl %ecx,_ipending jnc doreti_next /* some intr cleared memory copy */ #endif /* SMP */ - /* + * Execute handleable interrupt + * * Set up JUMP to _ihandlers[%ecx] for HWIs. * Set up CALL of _ihandlers[%ecx] for SWIs. * This is a bit early for the SMP case - we have to push %ecx and @@ -247,25 +216,10 @@ doreti_unpend: */ movl _ihandlers(,%ecx,4),%edx cmpl $NHWI,%ecx - jae doreti_swi - cli + jae doreti_swi /* software interrupt handling */ + cli /* else hardware int handling */ #ifdef SMP - pushl %edx /* preserve %edx */ -#ifdef APIC_INTR_DIAGNOSTIC - pushl %ecx -#endif - pushl %eax /* preserve %eax */ - ICPL_LOCK -#ifdef CPL_AND_CML - popl _cml -#else - popl _cpl -#endif - FAST_ICPL_UNLOCK -#ifdef APIC_INTR_DIAGNOSTIC - popl %ecx -#endif - popl %edx + movl %eax,_cpl /* same as non-smp case right now */ #else movl %eax,_cpl #endif @@ -292,9 +246,6 @@ doreti_unpend: ALIGN_TEXT doreti_swi: -#ifdef SMP - TEST_CIL -#endif pushl %eax /* * At least the SWI_CLOCK handler has to run at a possibly strictly @@ -304,29 +255,18 @@ doreti_swi: * in dying interrupt frames and about 12 HWIs nested in active * interrupt frames. There are only 4 different SWIs and the HWI * and SWI masks limit the nesting further. + * + * The SMP case is currently the same as the non-SMP case. */ #ifdef SMP - orl imasks(,%ecx,4), %eax - pushl %ecx /* preserve for use by _swi_generic */ - pushl %edx /* save handler entry point */ - cli /* prevent INT deadlock */ - pushl %eax /* save cpl|cml */ - ICPL_LOCK -#ifdef CPL_AND_CML - popl _cml /* restore cml */ -#else - popl _cpl /* restore cpl */ -#endif - FAST_ICPL_UNLOCK - sti - popl %edx /* restore handler entry point */ - popl %ecx + orl imasks(,%ecx,4), %eax /* or in imasks */ + movl %eax,_cpl /* set cpl for call */ #else orl imasks(,%ecx,4),%eax movl %eax,_cpl #endif call %edx - popl %eax + popl %eax /* cpl to restore */ jmp doreti_next ALIGN_TEXT @@ -336,9 +276,6 @@ doreti_ast: movl $T_ASTFLT,TF_TRAPNO(%esp) call _trap subl %eax,%eax /* recover cpl|cml */ -#ifdef CPL_AND_CML - movl %eax, _cpl -#endif movb $1,_intr_nesting_level /* for doreti_next to decrement */ jmp doreti_next |
