Use %fs to access per-cpu variables in uni-processor kernels the same

as multi-processor kernels.  The old way made it difficult for kernel
modules to be portable between uni-processor and multi-processor
kernels.  It is no longer necessary to jump through hoops.

- always load %fs with the private segment on entry to the kernel
- change the type of the self referntial pointer from struct privatespace
  to struct globaldata
- make the globaldata symbol have value 0 in all cases, so the symbols
  in globals.s are always offsets, not aliases for fields in globaldata
- define the globaldata space used for uniprocessor kernels in C, rather
  than assembler
- change the assmebly language accessors to use %fs, add a macro
  PCPU_ADDR(member, reg), which loads the register reg with the address
  of the per-cpu variable member

1 files changed, 1 insertions, 3 deletions

diff --git a/sys/i386/include/globaldata.h b/sys/i386/include/globaldata.h
index 27884997a535..90c3bd733df2 100644
--- a/sys/i386/include/globaldata.h
+++ b/sys/i386/include/globaldata.h
@@ -53,7 +53,7 @@
  * other processors"
  */
 struct globaldata {
-	struct privatespace *gd_prvspace;	/* self-reference */
+	struct globaldata *gd_prvspace;		/* self-reference */
 	struct proc	*gd_curproc;
 	struct proc	*gd_npxproc;
 	struct pcb	*gd_curpcb;
@@ -92,8 +92,6 @@ struct globaldata {
 #endif
 };
 
-extern struct globaldata globaldata;
-
 SLIST_HEAD(cpuhead, globaldata);
 extern struct cpuhead cpuhead;