Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files. =================================================================== RCS file: /ftp/cvs/cvsroot/src/sys/arch/i386/i386/locore.S,v rcsdiff: /ftp/cvs/cvsroot/src/sys/arch/i386/i386/locore.S,v: warning: Unknown phrases like `commitid ...;' are present. retrieving revision 1.45.2.3 retrieving revision 1.48 diff -u -p -r1.45.2.3 -r1.48 --- src/sys/arch/i386/i386/locore.S 2007/02/27 16:51:38 1.45.2.3 +++ src/sys/arch/i386/i386/locore.S 2007/05/17 14:51:21 1.48 @@ -1,7 +1,7 @@ -/* $NetBSD: locore.S,v 1.45.2.3 2007/02/27 16:51:38 yamt Exp $ */ +/* $NetBSD: locore.S,v 1.48 2007/05/17 14:51:21 yamt Exp $ */ /*- - * Copyright (c) 1998, 2000, 2004 The NetBSD Foundation, Inc. + * Copyright (c) 1998, 2000, 2004, 2006, 2007 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation @@ -70,15 +70,10 @@ * @(#)locore.s 7.3 (Berkeley) 5/13/91 */ -#include "opt_compat_netbsd.h" #include "opt_compat_oldboot.h" #include "opt_cputype.h" #include "opt_ddb.h" -#include "opt_ipkdb.h" -#include "opt_lockdebug.h" -#include "opt_multiprocessor.h" #include "opt_realmem.h" -#include "opt_user_ldt.h" #include "opt_vm86.h" #include "npx.h" @@ -94,44 +89,16 @@ #include #include #include - -#if NLAPIC > 0 #include -#endif - #include - -/* LINTSTUB: include */ -/* LINTSTUB: include */ -/* LINTSTUB: include */ - #include +#include +#include /* XXX temporary kluge; these should not be here */ /* Get definitions for IOM_BEGIN, IOM_END, and IOM_SIZE */ #include - -/* Disallow old names for REALBASEMEM */ -#ifdef BIOSBASEMEM -#error BIOSBASEMEM option deprecated; use REALBASEMEM only if memory size reported by latest boot block is incorrect -#endif - -/* Disallow old names for REALEXTMEM */ -#ifdef EXTMEM_SIZE -#error EXTMEM_SIZE option deprecated; use REALEXTMEM only if memory size reported by latest boot block is incorrect -#endif -#ifdef BIOSEXTMEM -#error BIOSEXTMEM option deprecated; use REALEXTMEM only if memory size reported by latest boot block is incorrect -#endif - -#include - - -#ifdef MULTIPROCESSOR -#include -#endif - /* * Initialization */ @@ -142,9 +109,7 @@ .globl _C_LABEL(atdevbase) .globl _C_LABEL(proc0uarea),_C_LABEL(PDPpaddr) .globl _C_LABEL(gdt) -#ifdef I586_CPU .globl _C_LABEL(idt) -#endif .globl _C_LABEL(lapic_tpr) #if NLAPIC > 0 @@ -170,9 +135,7 @@ _C_LABEL(lapic_tpr): .long 0 #endif - -_C_LABEL(cpu): .long 0 # are we 386, 386sx, or 486, - # or Pentium, or.. +_C_LABEL(cpu): .long 0 # are we 80486, Pentium, or.. _C_LABEL(atdevbase): .long 0 # location of start of iomem in virtual _C_LABEL(proc0uarea): .long 0 _C_LABEL(PDPpaddr): .long 0 # paddr of PDP, for libkvm @@ -625,13 +588,13 @@ begin: /* * void lwp_trampoline(void); + * * This is a trampoline function pushed onto the stack of a newly created * process in order to do some additional setup. The trampoline is entered by * cpu_switch()ing to the process, so we abuse the callee-saved registers used * by cpu_switch() to store the information about the stub to call. * NOTE: This function does not have a normal calling sequence! */ -/* LINTSTUB: Func: void lwp_trampoline(void) */ NENTRY(lwp_trampoline) pushl %ebp xorl %ebp,%ebp @@ -645,12 +608,12 @@ NENTRY(lwp_trampoline) INTRFASTEXIT /* NOTREACHED */ -/*****************************************************************************/ -#ifdef COMPAT_16 /* - * Signal trampoline; copied to top of user stack. + * sigcode() + * + * Signal trampoline; copied to top of user stack. Used only for + * compatibility with old releases of NetBSD. */ -/* LINTSTUB: Var: char sigcode[1], esigcode[1]; */ NENTRY(sigcode) /* * Handler has returned here as if we called it. The sigcontext @@ -665,23 +628,16 @@ NENTRY(sigcode) int $0x80 # exit if sigreturn fails .globl _C_LABEL(esigcode) _C_LABEL(esigcode): -#endif - -/*****************************************************************************/ - -/* - * The following is i386-specific nonsense. - */ /* * void lgdt(struct region_descriptor *rdp); + * * Load a new GDT pointer (and do any necessary cleanup). * XXX It's somewhat questionable whether reloading all the segment registers * is necessary, since the actual descriptor data is not changed except by * process creation and exit, both of which clean up via task switches. OTOH, * this only happens at run time when the GDT is resized. */ -/* LINTSTUB: Func: void lgdt(struct region_descriptor *rdp) */ NENTRY(lgdt) /* Reload the descriptor table. */ movl 4(%esp),%eax @@ -703,20 +659,22 @@ NENTRY(lgdt) pushl %eax lret +/* + * void x86_flush() + * + * Flush instruction pipelines by doing an intersegment (far) return. + */ NENTRY(x86_flush) - /* Reload code selector by doing intersegment return. */ popl %eax pushl $GSEL(GCODE_SEL, SEL_KPL) pushl %eax lret -/*****************************************************************************/ - /* - * These functions are primarily used by DDB. + * int setjmp(label_t *) + * + * Used primarily by DDB. */ - -/* LINTSTUB: Func: int setjmp (label_t *l) */ ENTRY(setjmp) movl 4(%esp),%eax movl %ebx,(%eax) # save ebx @@ -726,10 +684,14 @@ ENTRY(setjmp) movl %edi,16(%eax) # save edi movl (%esp),%edx # get rta movl %edx,20(%eax) # save eip - xorl %eax,%eax # return (0); + xorl %eax,%eax # return 0 ret -/* LINTSTUB: Func: void longjmp (label_t *l) */ +/* + * int longjmp(label_t *) + * + * Used primarily by DDB. + */ ENTRY(longjmp) movl 4(%esp),%eax movl (%eax),%ebx # restore ebx @@ -739,30 +701,17 @@ ENTRY(longjmp) movl 16(%eax),%edi # restore edi movl 20(%eax),%edx # get rta movl %edx,(%esp) # put in return frame - xorl %eax,%eax # return (1); - incl %eax + movl $1,%eax # return 1 ret -/*****************************************************************************/ - - .globl _C_LABEL(uvmexp),_C_LABEL(panic) - -#ifdef DIAGNOSTIC -NENTRY(switch_error) - pushl $1f - call _C_LABEL(panic) - /* NOTREACHED */ -1: .asciz "cpu_switch" -#endif /* DIAGNOSTIC */ - /* * struct lwp *cpu_switchto(struct lwp *oldlwp, struct newlwp) * * 1. if (oldlwp != NULL), save its context. * 2. then, restore context of newlwp. * - * Note that the stack frame layout is known to "struct switchframe" - * in and to the code in cpu_lwp_fork() which initializes + * Note that the stack frame layout is known to "struct switchframe" in + * and to the code in cpu_lwp_fork() which initializes * it for a new lwp. */ ENTRY(cpu_switchto) @@ -772,138 +721,107 @@ ENTRY(cpu_switchto) movl 16(%esp),%esi # oldlwp movl 20(%esp),%edi # newlwp - testl %esi,%esi - jz switch_skipsave - - /* - * Save old context. - */ + jz 1f + /* Save old context. */ movl L_ADDR(%esi),%eax movl %esp,PCB_ESP(%eax) movl %ebp,PCB_EBP(%eax) -switch_skipsave: - - /* - * Switch to newlwp's stack. - */ - - movl L_ADDR(%edi),%ebx + /* Switch to newlwp's stack. */ +1: movl L_ADDR(%edi),%ebx movl PCB_EBP(%ebx),%ebp movl PCB_ESP(%ebx),%esp - /* - * Restore the rest of newlwp's context. - * - * Registers: - * %ebx - new pcb - * %edi - new lwp - */ - -#if 0 - /* Don't bother with the rest if switching to a system process. */ - testl $LK_SYSTEM,L_FLAG(%edi); - jnz switch_restored -#endif - - /* Switch TSS. Reset "task busy" flag before loading. */ + /* Switch TSS. Reset "task busy" flag before loading. */ movl %cr3,%eax - movl %eax,PCB_CR3(%ebx) /* for TSS gates */ - -#ifdef MULTIPROCESSOR + movl %eax,PCB_CR3(%ebx) # for TSS gates movl CPUVAR(GDT),%eax -#else - /* Load TSS info. */ - movl _C_LABEL(gdt),%eax -#endif movl L_MD_TSS_SEL(%edi),%edx - andl $~0x0200,4(%eax,%edx, 1) ltr %dx -#if 0 -switch_restored: -#endif + /* Set curlwp. */ + movl %edi,CPUVAR(CURLWP) - movl $0,CPUVAR(RESCHED) + /* Don't bother with the rest if switching to a system process. */ + testl $LW_SYSTEM,L_FLAG(%edi) + jnz 4f - /* Restore cr0 (including FPU state). */ - cli + /* Is this process using RAS (restartable atomic sequences)? */ + movl L_PROC(%edi),%eax + cmpl $0,P_RASLIST(%eax) + jne 5f + + /* + * Restore cr0 (including FPU state). Raise the IPL to IPL_IPI. + * FPU IPIs can alter the LWP's saved cr0. Dropping the priority + * is deferred until mi_switch(), when cpu_switchto() returns. + */ +2: movl $IPL_IPI,CPUVAR(ILEVEL) movl PCB_CR0(%ebx),%ecx -#ifdef MULTIPROCESSOR + movl %cr0,%edx + /* * If our floating point registers are on a different CPU, * set CR0_TS so we'll trap rather than reuse bogus state. */ movl PCB_FPCPU(%ebx),%eax cmpl CPUVAR(SELF),%eax - jz 1f + je 3f orl $CR0_TS,%ecx -1: -#endif - movl %ecx,%cr0 - - /* Interrupts are okay again. */ - sti - /* - * Check for restartable atomic sequences (RAS) - */ - - movl L_PROC(%edi),%ebx - cmpl $0,P_RASLIST(%ebx) - jne check_ras + /* Reloading CR0 is very expensive - avoid if possible. */ +3: cmpl %edx,%ecx + je 4f + movl %ecx,%cr0 -switch_return: - movl %esi,%eax # return 'oldlwp' + /* Return to the new LWP, returning 'oldlwp' in %eax. */ +4: movl %esi,%eax popl %edi popl %esi popl %ebx ret -check_ras: - movl L_MD_REGS(%edi),%ebx - movl TF_EIP(%ebx),%eax + /* Check for restartable atomic sequences (RAS). */ +5: movl L_MD_REGS(%edi),%ecx + pushl TF_EIP(%ecx) pushl %eax - pushl %esi call _C_LABEL(ras_lookup) addl $8,%esp cmpl $-1,%eax - je switch_return + je 2b movl %eax,TF_EIP(%ebx) - jmp switch_return + jmp 2b /* * void savectx(struct pcb *pcb); + * * Update pcb, saving current processor state. */ -/* LINTSTUB: Func: void savectx(struct pcb *pcb) */ ENTRY(savectx) movl 4(%esp),%edx # edx = pcb - - /* Save stack pointers. */ movl %esp,PCB_ESP(%edx) movl %ebp,PCB_EBP(%edx) - ret /* + * osyscall() + * * Old call gate entry for syscall */ -/* LINTSTUB: Var: char Xosyscall[1]; */ IDTVEC(osyscall) - /* Set eflags in trap frame. */ - pushfl + pushfl # set eflags in trap frame popl 8(%esp) pushl $7 # size of instruction for restart jmp syscall1 /* + * syscall() + * * Trap gate entry for syscall */ -/* LINTSTUB: Var: char Xsyscall[1]; */ IDTVEC(syscall) pushl $2 # size of instruction for restart syscall1: @@ -979,7 +897,9 @@ syscall1: * latch stuff in probintr() can be moved to npxprobe(). */ -/* LINTSTUB: Func: void probeintr(void) */ +/* + * void probeintr(void) + */ NENTRY(probeintr) ss incl _C_LABEL(npx_intrs_while_probing) @@ -992,14 +912,18 @@ NENTRY(probeintr) popl %eax iret -/* LINTSTUB: Func: void probetrap(void) */ +/* + * void probetrap(void) + */ NENTRY(probetrap) ss incl _C_LABEL(npx_traps_while_probing) fnclex iret -/* LINTSTUB: Func: int npx586bug1(int a, int b) */ +/* + * int npx586bug1(int a, int b) + */ NENTRY(npx586bug1) fildl 4(%esp) # x fildl 8(%esp) # y