PERFORCE change 133827 for review

[Oleksandr Tymoshenko]

http://perforce.freebsd.org/chv.cgi?CH=133827

Change 133827 by gonzo at gonzo_jeeves on 2008/01/21 23:29:06

	o Back out  a bit hackerish solution for kstack0 located in 
	    KSEG0 while cpu_thread_alloc expects to get it in KSEG2 
	    presented by changesets 133821 and 133822. 

Affected files ...

.. //depot/projects/mips2-jnpr/src/sys/mips/mips/vm_machdep.c#10 edit

Differences ...

==== //depot/projects/mips2-jnpr/src/sys/mips/mips/vm_machdep.c#10 (text+ko) ====

@@ -140,22 +140,13 @@
 	td2->td_frame->v1 = 1;
 	td2->td_frame->a3 = 0;
 
-	/*
-	 * thread 0 has its stack in KSEG0 space.  In that case, there's
-	 * nothing to do since we're not going to change the physical address
-	 * of where we're swapped in at...
-	 */
-	pte = pmap_segmap(kernel_pmap, (vm_offset_t)td2->td_kstack);
-	if (pte == NULL) {
-		if ((vm_offset_t)td2->td_kstack < MIPS_KSEG0_START &&
-		    (vm_offset_t)td2->td_kstack > MIPS_KSEG0_END)
-			panic("cpu_fork: invalid segmap");
-	} else {
-		pte += ((vm_offset_t)td2->td_kstack >> PGSHIFT) & (NPTEPG - 1);
-		for (i = 0; i < KSTACK_PAGES; i++) {
-			td2->td_md.md_upte[i] = *pte & ~(PG_RO|PG_WIRED);
-			pte++;
-		}
+	if (!(pte = pmap_segmap(kernel_pmap, (vm_offset_t)td2->td_kstack)))
+		panic("cpu_fork: invalid segmap");
+	pte += ((vm_offset_t)td2->td_kstack >> PGSHIFT) & (NPTEPG - 1);
+
+	for (i = 0; i < KSTACK_PAGES; i++) {
+		td2->td_md.md_upte[i] = *pte & ~(PG_RO|PG_WIRED);
+		pte++;
 	}
 
 	if (td1 == PCPU_GET(fpcurthread))
@@ -258,15 +249,6 @@
 	    td->td_kstack_pages * PAGE_SIZE) - 1;
 	td->td_frame = &td->td_pcb->pcb_regs;
 
-	/*
-	 * thread 0 has its stack in KSEG0 space.  In that case, there's
-	 * nothing to do since we're not going to change the physical address
-	 * of where we're swapped in at...
-	 */
-	if ((vm_offset_t)td->td_kstack > MIPS_KSEG0_START &&
-	    (vm_offset_t)td->td_kstack < MIPS_KSEG0_END)
-		return;
-	
 	if (!(pte = pmap_segmap(kernel_pmap, (vm_offset_t)td->td_kstack)))
 		panic("cpu_thread_alloc: invalid segmap");
 	pte += ((vm_offset_t)td->td_kstack >> PGSHIFT) & (NPTEPG - 1);