amd64/138220: [patch] FreeBSD/amd64 can't see all system memory

[John Baldwin]

Can you try this alternate patch instead?  I am leery of manipulating the SMAP
directly since it resides in the kernel's module metadata which in theory
should be read-only.  This patch changes the SMAP code to do an insertion sort
into the physmap[] array for each new entry that is added.  I also changed the
amd64 code to use a separate static routine to add each entry similar to i386
which fixes the bug with overlapping regions that you noted while keeping the
SMAP code identical between the two archs.

--- //depot/vendor/freebsd/src/sys/amd64/amd64/machdep.c	2009/08/20 23:00:20
+++ //depot/user/jhb/numa/sys/amd64/amd64/machdep.c	2009/09/14 19:37:10
@@ -1192,6 +1192,77 @@
 
 u_int basemem;
 
+static int
+add_smap_entry(struct bios_smap *smap, vm_paddr_t *physmap, int *physmap_idxp)
+{
+	int i, insert_idx, physmap_idx;
+
+	physmap_idx = *physmap_idxp;
+
+	if (boothowto & RB_VERBOSE)
+		printf("SMAP type=%02x base=%016lx len=%016lx\n",
+		    smap->type, smap->base, smap->length);
+
+	if (smap->type != SMAP_TYPE_MEMORY)
+		return (1);
+
+	if (smap->length == 0)
+		return (0);
+
+	/*
+	 * Find insertion point while checking for overlap.  Start off by
+	 * assuming the new entry will be added to the end.
+	 */
+	insert_idx = physmap_idx + 2;
+	for (i = 0; i <= physmap_idx; i += 2) {
+		if (smap->base < physmap[i + 1]) {
+			if (smap->base + smap->length <= physmap[i]) {
+				insert_idx = i;
+				break;
+			}
+			if (boothowto & RB_VERBOSE)
+				printf(
+	"Overlapping or non-monotonic memory region, ignoring second region\n");
+			return (1);
+		}
+	}
+
+	/* See if we can prepend to the next entry. */
+	if (insert_idx <= physmap_idx &&
+	    smap->base + smap->length == physmap[insert_idx]) {
+		physmap[insert_idx] = smap->base;
+		return (1);
+	}
+
+	/* See if we can append to the previous entry. */
+	if (insert_idx > 0 && smap->base == physmap[insert_idx - 1]) {
+		physmap[insert_idx - 1] += smap->length;
+		return (1);
+	}
+
+	physmap_idx += 2;
+	*physmap_idxp = physmap_idx;
+	if (physmap_idx == PHYSMAP_SIZE) {
+		printf(
+		"Too many segments in the physical address map, giving up\n");
+		return (0);
+	}
+
+	/*
+	 * Move the last 'N' entries down to make room for the new
+	 * entry if needed.
+	 */
+	for (i = physmap_idx - 2; i > insert_idx; i -= 2) {
+		physmap[i] = physmap[i - 2];
+		physmap[i + 1] = physmap[i - 1];
+	}
+
+	/* Insert the new entry. */
+	physmap[insert_idx] = smap->base;
+	physmap[insert_idx + 1] = smap->base + smap->length;
+	return (1);
+}
+
 /*
  * Populate the (physmap) array with base/bound pairs describing the
  * available physical memory in the system, then test this memory and
@@ -1235,40 +1306,9 @@
 	smapsize = *((u_int32_t *)smapbase - 1);
 	smapend = (struct bios_smap *)((uintptr_t)smapbase + smapsize);
 
-	for (smap = smapbase; smap < smapend; smap++) {
-		if (boothowto & RB_VERBOSE)
-			printf("SMAP type=%02x base=%016lx len=%016lx\n",
-			    smap->type, smap->base, smap->length);
-
-		if (smap->type != SMAP_TYPE_MEMORY)
-			continue;
-
-		if (smap->length == 0)
-			continue;
-
-		for (i = 0; i <= physmap_idx; i += 2) {
-			if (smap->base < physmap[i + 1]) {
-				if (boothowto & RB_VERBOSE)
-					printf(
-	"Overlapping or non-monotonic memory region, ignoring second region\n");
-				continue;
-			}
-		}
-
-		if (smap->base == physmap[physmap_idx + 1]) {
-			physmap[physmap_idx + 1] += smap->length;
-			continue;
-		}
-
-		physmap_idx += 2;
-		if (physmap_idx == PHYSMAP_SIZE) {
-			printf(
-		"Too many segments in the physical address map, giving up\n");
+	for (smap = smapbase; smap < smapend; smap++)
+		if (!add_smap_entry(smap, physmap, &physmap_idx))
 			break;
-		}
-		physmap[physmap_idx] = smap->base;
-		physmap[physmap_idx + 1] = smap->base + smap->length;
-	}
 
 	/*
 	 * Find the 'base memory' segment for SMP
--- //depot/vendor/freebsd/src/sys/i386/i386/machdep.c	2009/09/04 14:55:14
+++ //depot/user/jhb/numa/sys/i386/i386/machdep.c	2009/09/14 19:37:10
@@ -1946,7 +1946,7 @@
 static int
 add_smap_entry(struct bios_smap *smap, vm_paddr_t *physmap, int *physmap_idxp)
 {
-	int i, physmap_idx;
+	int i, insert_idx, physmap_idx;
 
 	physmap_idx = *physmap_idxp;
 	
@@ -1968,8 +1968,17 @@
 	}
 #endif
 
+	/*
+	 * Find insertion point while checking for overlap.  Start off by
+	 * assuming the new entry will be added to the end.
+	 */
+	insert_idx = physmap_idx + 2;
 	for (i = 0; i <= physmap_idx; i += 2) {
 		if (smap->base < physmap[i + 1]) {
+			if (smap->base + smap->length <= physmap[i]) {
+				insert_idx = i;
+				break;
+			}
 			if (boothowto & RB_VERBOSE)
 				printf(
 	"Overlapping or non-monotonic memory region, ignoring second region\n");
@@ -1977,8 +1986,16 @@
 		}
 	}
 
-	if (smap->base == physmap[physmap_idx + 1]) {
-		physmap[physmap_idx + 1] += smap->length;
+	/* See if we can prepend to the next entry. */
+	if (insert_idx <= physmap_idx &&
+	    smap->base + smap->length == physmap[insert_idx]) {
+		physmap[insert_idx] = smap->base;
+		return (1);
+	}
+
+	/* See if we can append to the previous entry. */
+	if (insert_idx > 0 && smap->base == physmap[insert_idx - 1]) {
+		physmap[insert_idx - 1] += smap->length;
 		return (1);
 	}
 
@@ -1989,8 +2006,19 @@
 		"Too many segments in the physical address map, giving up\n");
 		return (0);
 	}
-	physmap[physmap_idx] = smap->base;
-	physmap[physmap_idx + 1] = smap->base + smap->length;
+
+	/*
+	 * Move the last 'N' entries down to make room for the new
+	 * entry if needed.
+	 */
+	for (i = physmap_idx - 2; i > insert_idx; i -= 2) {
+		physmap[i] = physmap[i - 2];
+		physmap[i + 1] = physmap[i - 1];
+	}
+
+	/* Insert the new entry. */
+	physmap[insert_idx] = smap->base;
+	physmap[insert_idx + 1] = smap->base + smap->length;
 	return (1);
 }
 


-- 
John Baldwin