PERFORCE change 102581 for review

[John Baldwin]

http://perforce.freebsd.org/chv.cgi?CH=102581

Change 102581 by jhb at jhb_mutex on 2006/07/27 19:13:24

	Really fix the hw.physmem stuff.  Not only do we have to not change
	the physmap[], we also have to make sure Maxmem retains the correct
	value.

Affected files ...

.. //depot/projects/smpng/sys/amd64/amd64/machdep.c#55 edit
.. //depot/projects/smpng/sys/i386/i386/machdep.c#111 edit

Differences ...

==== //depot/projects/smpng/sys/amd64/amd64/machdep.c#55 (text+ko) ====

@@ -947,6 +947,13 @@
 	if (TUNABLE_ULONG_FETCH("hw.physmem", &physmem_tunable))
 		Maxmem = atop(physmem_tunable);
 
+	/*
+	 * Don't allow MAXMEM or hw.physmem to extend the amount of memory
+	 * in the system.
+	 */
+	if (Maxmem > atop(physmap[physmap_idx + 1]))
+		Maxmem = atop(physmap[physmap_idx + 1]);
+
 	if (atop(physmap[physmap_idx + 1]) != Maxmem &&
 	    (boothowto & RB_VERBOSE))
 		printf("Physical memory use set to %ldK\n", Maxmem * 4);

==== //depot/projects/smpng/sys/i386/i386/machdep.c#111 (text+ko) ====

@@ -1661,6 +1661,7 @@
 	bzero(&vmf, sizeof(vmf));
 	bzero(physmap, sizeof(physmap));
 	basemem = 0;
+	has_smap = 0;
 
 	/*
 	 * Some newer BIOSes has broken INT 12H implementation which cause
@@ -1884,16 +1885,22 @@
 	if (TUNABLE_ULONG_FETCH("hw.physmem", &physmem_tunable))
 		Maxmem = atop(physmem_tunable);
 
+	/*
+	 * If we have an SMAP, don't allow MAXMEM or hw.physmem to extend
+	 * the amount of memory in the system.
+	 */
+	if (has_smap && Maxmem > atop(physmap[physmap_idx + 1]))
+		Maxmem = atop(physmap[physmap_idx + 1]);
+
 	if (atop(physmap[physmap_idx + 1]) != Maxmem &&
 	    (boothowto & RB_VERBOSE))
 		printf("Physical memory use set to %ldK\n", Maxmem * 4);
 
 	/*
-	 * If Maxmem has been increased beyond what the system has detected
-	 * and we didn't get the memory layout via SMAP, extend the last
-	 * memory segment to the new limit.
+	 * If Maxmem has been increased beyond what the system has detected,
+	 * extend the last memory segment to the new limit.
 	 */ 
-	if (!has_smap && atop(physmap[physmap_idx + 1]) < Maxmem)
+	if (atop(physmap[physmap_idx + 1]) < Maxmem)
 		physmap[physmap_idx + 1] = ptoa((vm_paddr_t)Maxmem);
 
 	/* call pmap initialization to make new kernel address space */