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 1.48.8.7
retrieving revision 1.50.2.6
diff -u -p -r1.48.8.7 -r1.50.2.6
--- src/sys/arch/i386/i386/locore.S	2007/12/09 19:35:21	1.48.8.7
+++ src/sys/arch/i386/i386/locore.S	2007/10/04 15:04:31	1.50.2.6
@@ -1,4 +1,4 @@
-/*	$NetBSD: locore.S,v 1.48.8.7 2007/12/09 19:35:21 jmcneill Exp $	*/
+/*	$NetBSD: locore.S,v 1.50.2.6 2007/10/04 15:04:31 yamt Exp $	*/
 
 /*
  * Copyright-o-rama!
@@ -111,6 +111,7 @@
  */
 
 #include "opt_compat_oldboot.h"
+#include "opt_cputype.h"
 #include "opt_ddb.h"
 #include "opt_realmem.h"
 #include "opt_vm86.h"
@@ -463,11 +464,10 @@ try586:	/* Use the `cpuid' instruction. 
 	addl	$PGOFSET,%esi			# page align up
 	andl	$~PGOFSET,%esi
 
-	/* nkptp[1] = (esi + ~L2_FRAME) >> L2_SHIFT + 1; */
+	/* nkptp = (esi + ~L2_FRAME) >> L2_SHIFT; */
 	movl	%esi,%eax
 	addl	$~L2_FRAME,%eax
 	shrl	$L2_SHIFT,%eax
-	incl	%eax		/* one more ptp for VAs stolen by bootstrap */
 1:	movl	%eax,RELOC(nkptp)+1*4
 
 	/* tablesize = (1 + UPAGES + nkptp) << PGSHIFT; */
@@ -479,7 +479,6 @@ try586:	/* Use the `cpuid' instruction. 
 	addl	%esi,%eax
 	addl	$~L2_FRAME,%eax
 	shrl	$L2_SHIFT,%eax
-	incl	%eax
 	cmpl	%eax,RELOC(nkptp)+1*4
 	jnz	1b
 
@@ -503,6 +502,7 @@ try586:	/* Use the `cpuid' instruction. 
 	 * 32 bit mode. So use the bottom 32 bits.
  	 */
  	movl	$RELOC(__data_start),%edx
+ 	addl	$PGOFSET,%edx
 	andl	$~PGOFSET,%edx
 
  	/*
@@ -688,6 +688,47 @@ NENTRY(sigcode)
 _C_LABEL(esigcode):
 
 /*
+ * 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.
+ */
+NENTRY(lgdt)
+	/* Reload the descriptor table. */
+	movl	4(%esp),%eax
+	lgdt	(%eax)
+	/* Flush the prefetch queue. */
+	jmp	1f
+	nop
+1:	/* Reload "stale" selectors. */
+	movl	$GSEL(GDATA_SEL, SEL_KPL),%eax
+	movw	%ax,%ds
+	movw	%ax,%es
+	movw	%ax,%gs
+	movw	%ax,%ss
+	movl	$GSEL(GCPU_SEL, SEL_KPL),%eax
+	movw	%ax,%fs
+	/* Reload code selector by doing intersegment return. */
+	popl	%eax
+	pushl	$GSEL(GCODE_SEL, SEL_KPL)
+	pushl	%eax
+	lret
+
+/*
+ * void x86_flush()
+ *
+ * Flush instruction pipelines by doing an intersegment (far) return.
+ */
+NENTRY(x86_flush)
+	popl	%eax
+	pushl	$GSEL(GCODE_SEL, SEL_KPL)
+	pushl	%eax
+	lret
+
+/*
  * int setjmp(label_t *)
  *
  * Used primarily by DDB.
@@ -722,8 +763,7 @@ ENTRY(longjmp)
 	ret
 
 /*
- * struct lwp *cpu_switchto(struct lwp *oldlwp, struct newlwp,
- *			    bool returning)
+ * struct lwp *cpu_switchto(struct lwp *oldlwp, struct newlwp)
  *
  *	1. if (oldlwp != NULL), save its context.
  *	2. then, restore context of newlwp.
@@ -739,7 +779,6 @@ ENTRY(cpu_switchto)
 
 	movl	16(%esp),%esi		# oldlwp
 	movl	20(%esp),%edi		# newlwp
-	movl	24(%esp),%edx		# returning
 	testl	%esi,%esi
 	jz	1f
 
@@ -753,35 +792,21 @@ ENTRY(cpu_switchto)
 	movl	PCB_EBP(%ebx),%ebp
 	movl	PCB_ESP(%ebx),%esp
 
-	/* Set curlwp. */
-	movl	%edi,CPUVAR(CURLWP)
-
-	/* Skip the rest if returning to a pinned LWP. */
-	testl	%edx,%edx
-	jnz	4f
-
 	/* Switch TSS.  Reset "task busy" flag before loading. */
 	movl	%cr3,%eax
 	movl	%eax,PCB_CR3(%ebx)	# for TSS gates
-	movl	CPUVAR(GDT),%ecx
+	movl	CPUVAR(GDT),%eax
 	movl	L_MD_TSS_SEL(%edi),%edx
-	andl	$~0x0200,4(%ecx,%edx, 1)
+	andl	$~0x0200,4(%eax,%edx, 1)
 	ltr	%dx
 
+	/* Set curlwp. */
+	movl	%edi,CPUVAR(CURLWP)
+
 	/* Don't bother with the rest if switching to a system process. */
 	testl	$LW_SYSTEM,L_FLAG(%edi)
 	jnz	4f
 
-	/* Restore thread-private %fs/%gs descriptors. */
-	movl	PCB_FSD(%ebx), %eax
-	movl	PCB_FSD+4(%ebx), %edx
-	movl	%eax, (GUFS_SEL*8)(%ecx)
-	movl	%edx, (GUFS_SEL*8+4)(%ecx)
-	movl	PCB_GSD(%ebx), %eax
-	movl	PCB_GSD+4(%ebx), %edx
-	movl	%eax, (GUGS_SEL*8)(%ecx)
-	movl	%edx, (GUGS_SEL*8+4)(%ecx)
-
 	/* Is this process using RAS (restartable atomic sequences)? */
 	movl	L_PROC(%edi),%eax
 	cmpl	$0,P_RASLIST(%eax)
@@ -911,9 +936,10 @@ syscall1:
 	pushl	$4f
 	call	_C_LABEL(printf)
 	addl	$4,%esp
-	pushl	$IPL_NONE
-	call	_C_LABEL(spllower)
-	addl	$4,%esp
+#ifdef DDB
+	int	$3
+#endif /* DDB */
+	movl	$IPL_NONE,CPUVAR(ILEVEL)
 	jmp	.Lsyscall_checkast
 4:	.asciz	"WARNING: SPL NOT LOWERED ON SYSCALL EXIT\n"
 5:	.asciz	"WARNING: SPL NOT ZERO ON SYSCALL ENTRY\n"