[new uImage] Introduce lmb from linux kernel for memory mgmt of boot images

Introduce the LMB lib used on PPC in the kernel as a clean way to manage
the memory spaces used by various boot images and structures.  This code
will allow us to simplify the code in bootm and its support functions.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

2 files changed, 281 insertions, 0 deletions

diff --git a/lib_generic/Makefile b/lib_generic/Makefile
index 9713353ddf7..b10793bd4c7 100644
--- a/lib_generic/Makefile
+++ b/lib_generic/Makefile
@@ -34,6 +34,7 @@ COBJS-y += crc32.o
 COBJS-y += ctype.o
 COBJS-y += display_options.o
 COBJS-y += div64.o
+COBJS-y += lmb.o
 COBJS-y += ldiv.o
 COBJS-y += sha1.o
 COBJS-y += string.o
diff --git a/lib_generic/lmb.c b/lib_generic/lmb.c
new file mode 100644
index 00000000000..3b8c805e881
--- /dev/null
+++ b/lib_generic/lmb.c
@@ -0,0 +1,280 @@
+/*
+ * Procedures for maintaining information about logical memory blocks.
+ *
+ * Peter Bergner, IBM Corp.	June 2001.
+ * Copyright (C) 2001 Peter Bergner.
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <common.h>
+#include <lmb.h>
+
+#define LMB_ALLOC_ANYWHERE	0
+
+void lmb_dump_all(struct lmb *lmb)
+{
+#ifdef DEBUG
+	unsigned long i;
+
+	debug("lmb_dump_all:\n");
+	debug("    memory.cnt		   = 0x%lx\n", lmb->memory.cnt);
+	debug("    memory.size		   = 0x%08x\n", lmb->memory.size);
+	for (i=0; i < lmb->memory.cnt ;i++) {
+		debug("    memory.reg[0x%x].base   = 0x%08x\n", i,
+			lmb->memory.region[i].base);
+		debug("		   .size   = 0x%08x\n",
+			lmb->memory.region[i].size);
+	}
+
+	debug("\n    reserved.cnt	   = 0x%lx\n", lmb->reserved.cnt);
+	debug("    reserved.size	   = 0x%08x\n", lmb->reserved.size);
+	for (i=0; i < lmb->reserved.cnt ;i++) {
+		debug("    reserved.reg[0x%x].base = 0x%08x\n", i,
+			lmb->reserved.region[i].base);
+		debug("		     .size = 0x%08x\n",
+			lmb->reserved.region[i].size);
+	}
+#endif /* DEBUG */
+}
+
+static unsigned long lmb_addrs_overlap(ulong base1,
+		ulong size1, ulong base2, ulong size2)
+{
+	return ((base1 < (base2+size2)) && (base2 < (base1+size1)));
+}
+
+static long lmb_addrs_adjacent(ulong base1, ulong size1,
+		ulong base2, ulong size2)
+{
+	if (base2 == base1 + size1)
+		return 1;
+	else if (base1 == base2 + size2)
+		return -1;
+
+	return 0;
+}
+
+static long lmb_regions_adjacent(struct lmb_region *rgn,
+		unsigned long r1, unsigned long r2)
+{
+	ulong base1 = rgn->region[r1].base;
+	ulong size1 = rgn->region[r1].size;
+	ulong base2 = rgn->region[r2].base;
+	ulong size2 = rgn->region[r2].size;
+
+	return lmb_addrs_adjacent(base1, size1, base2, size2);
+}
+
+static void lmb_remove_region(struct lmb_region *rgn, unsigned long r)
+{
+	unsigned long i;
+
+	for (i = r; i < rgn->cnt - 1; i++) {
+		rgn->region[i].base = rgn->region[i + 1].base;
+		rgn->region[i].size = rgn->region[i + 1].size;
+	}
+	rgn->cnt--;
+}
+
+/* Assumption: base addr of region 1 < base addr of region 2 */
+static void lmb_coalesce_regions(struct lmb_region *rgn,
+		unsigned long r1, unsigned long r2)
+{
+	rgn->region[r1].size += rgn->region[r2].size;
+	lmb_remove_region(rgn, r2);
+}
+
+void lmb_init(struct lmb *lmb)
+{
+	/* Create a dummy zero size LMB which will get coalesced away later.
+	 * This simplifies the lmb_add() code below...
+	 */
+	lmb->memory.region[0].base = 0;
+	lmb->memory.region[0].size = 0;
+	lmb->memory.cnt = 1;
+	lmb->memory.size = 0;
+
+	/* Ditto. */
+	lmb->reserved.region[0].base = 0;
+	lmb->reserved.region[0].size = 0;
+	lmb->reserved.cnt = 1;
+	lmb->reserved.size = 0;
+}
+
+/* This routine called with relocation disabled. */
+static long lmb_add_region(struct lmb_region *rgn, ulong base, ulong size)
+{
+	unsigned long coalesced = 0;
+	long adjacent, i;
+
+	if ((rgn->cnt == 1) && (rgn->region[0].size == 0)) {
+		rgn->region[0].base = base;
+		rgn->region[0].size = size;
+		return 0;
+	}
+
+	/* First try and coalesce this LMB with another. */
+	for (i=0; i < rgn->cnt; i++) {
+		ulong rgnbase = rgn->region[i].base;
+		ulong rgnsize = rgn->region[i].size;
+
+		if ((rgnbase == base) && (rgnsize == size))
+			/* Already have this region, so we're done */
+			return 0;
+
+		adjacent = lmb_addrs_adjacent(base,size,rgnbase,rgnsize);
+		if ( adjacent > 0 ) {
+			rgn->region[i].base -= size;
+			rgn->region[i].size += size;
+			coalesced++;
+			break;
+		}
+		else if ( adjacent < 0 ) {
+			rgn->region[i].size += size;
+			coalesced++;
+			break;
+		}
+	}
+
+	if ((i < rgn->cnt-1) && lmb_regions_adjacent(rgn, i, i+1) ) {
+		lmb_coalesce_regions(rgn, i, i+1);
+		coalesced++;
+	}
+
+	if (coalesced)
+		return coalesced;
+	if (rgn->cnt >= MAX_LMB_REGIONS)
+		return -1;
+
+	/* Couldn't coalesce the LMB, so add it to the sorted table. */
+	for (i = rgn->cnt-1; i >= 0; i--) {
+		if (base < rgn->region[i].base) {
+			rgn->region[i+1].base = rgn->region[i].base;
+			rgn->region[i+1].size = rgn->region[i].size;
+		} else {
+			rgn->region[i+1].base = base;
+			rgn->region[i+1].size = size;
+			break;
+		}
+	}
+
+	if (base < rgn->region[0].base) {
+		rgn->region[0].base = base;
+		rgn->region[0].size = size;
+	}
+
+	rgn->cnt++;
+
+	return 0;
+}
+
+/* This routine may be called with relocation disabled. */
+long lmb_add(struct lmb *lmb, ulong base, ulong size)
+{
+	struct lmb_region *_rgn = &(lmb->memory);
+
+	return lmb_add_region(_rgn, base, size);
+}
+
+long lmb_reserve(struct lmb *lmb, ulong base, ulong size)
+{
+	struct lmb_region *_rgn = &(lmb->reserved);
+
+	return lmb_add_region(_rgn, base, size);
+}
+
+long lmb_overlaps_region(struct lmb_region *rgn, ulong base,
+				ulong size)
+{
+	unsigned long i;
+
+	for (i=0; i < rgn->cnt; i++) {
+		ulong rgnbase = rgn->region[i].base;
+		ulong rgnsize = rgn->region[i].size;
+		if ( lmb_addrs_overlap(base,size,rgnbase,rgnsize) ) {
+			break;
+		}
+	}
+
+	return (i < rgn->cnt) ? i : -1;
+}
+
+ulong lmb_alloc(struct lmb *lmb, ulong size, ulong align)
+{
+	return lmb_alloc_base(lmb, size, align, LMB_ALLOC_ANYWHERE);
+}
+
+ulong lmb_alloc_base(struct lmb *lmb, ulong size, ulong align, ulong max_addr)
+{
+	ulong alloc;
+
+	alloc = __lmb_alloc_base(lmb, size, align, max_addr);
+
+	if (alloc == 0)
+		printf("ERROR: Failed to allocate 0x%lx bytes below 0x%lx.\n",
+		      size, max_addr);
+
+	return alloc;
+}
+
+static ulong lmb_align_down(ulong addr, ulong size)
+{
+	return addr & ~(size - 1);
+}
+
+static ulong lmb_align_up(ulong addr, ulong size)
+{
+	return (addr + (size - 1)) & ~(size - 1);
+}
+
+ulong __lmb_alloc_base(struct lmb *lmb, ulong size, ulong align, ulong max_addr)
+{
+	long i, j;
+	ulong base = 0;
+
+	for (i = lmb->memory.cnt-1; i >= 0; i--) {
+		ulong lmbbase = lmb->memory.region[i].base;
+		ulong lmbsize = lmb->memory.region[i].size;
+
+		if (max_addr == LMB_ALLOC_ANYWHERE)
+			base = lmb_align_down(lmbbase + lmbsize - size, align);
+		else if (lmbbase < max_addr) {
+			base = min(lmbbase + lmbsize, max_addr);
+			base = lmb_align_down(base - size, align);
+		} else
+			continue;
+
+		while ((lmbbase <= base) &&
+		       ((j = lmb_overlaps_region(&(lmb->reserved), base, size)) >= 0) )
+			base = lmb_align_down(lmb->reserved.region[j].base - size,
+					      align);
+
+		if ((base != 0) && (lmbbase <= base))
+			break;
+	}
+
+	if (i < 0)
+		return 0;
+
+	if (lmb_add_region(&(lmb->reserved), base, lmb_align_up(size, align)) < 0)
+		return 0;
+
+	return base;
+}
+
+int lmb_is_reserved(struct lmb *lmb, ulong addr)
+{
+	int i;
+
+	for (i = 0; i < lmb->reserved.cnt; i++) {
+		ulong upper = lmb->reserved.region[i].base +
+			lmb->reserved.region[i].size - 1;
+		if ((addr >= lmb->reserved.region[i].base) && (addr <= upper))
+			return 1;
+	}
+	return 0;
+}