Merge branch 'master' into for-next

8 files changed, 76 insertions, 595 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index 170d8ca901d8..5b916bc0fbae 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -181,9 +181,6 @@ config HAS_DMA
 config CHECK_SIGNATURE
 	bool
 
-config HAVE_LMB
-	boolean
-
 config CPUMASK_OFFSTACK
 	bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
 	help
diff --git a/lib/Makefile b/lib/Makefile
index 3f1062cbbff4..0bfabba1bb32 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -89,8 +89,6 @@ obj-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-notifier-error-inject.o
 
 lib-$(CONFIG_GENERIC_BUG) += bug.o
 
-obj-$(CONFIG_HAVE_LMB) += lmb.o
-
 obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o
 
 obj-$(CONFIG_DYNAMIC_DEBUG) += dynamic_debug.o
diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c
index 250ed11d3ed2..44524cc8c32a 100644
--- a/lib/atomic64_test.c
+++ b/lib/atomic64_test.c
@@ -114,7 +114,7 @@ static __init int test_atomic64(void)
 	BUG_ON(v.counter != r);
 
 #if defined(CONFIG_X86) || defined(CONFIG_MIPS) || defined(CONFIG_PPC) || \
-    defined(CONFIG_S390) || defined(_ASM_GENERIC_ATOMIC64_H)
+    defined(CONFIG_S390) || defined(_ASM_GENERIC_ATOMIC64_H) || defined(CONFIG_ARM)
 	INIT(onestwos);
 	BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
 	r -= one;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 3df8eb17a607..02afc2533728 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -692,7 +692,7 @@ static void ddebug_table_free(struct ddebug_table *dt)
  * Called in response to a module being unloaded.  Removes
  * any ddebug_table's which point at the module.
  */
-int ddebug_remove_module(char *mod_name)
+int ddebug_remove_module(const char *mod_name)
 {
 	struct ddebug_table *dt, *nextdt;
 	int ret = -ENOENT;
diff --git a/lib/genalloc.c b/lib/genalloc.c
index 736c3b06398e..1923f1490e72 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -128,7 +128,6 @@ unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
 		chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
 
 		end_bit = (chunk->end_addr - chunk->start_addr) >> order;
-		end_bit -= nbits + 1;
 
 		spin_lock_irqsave(&chunk->lock, flags);
 		start_bit = bitmap_find_next_zero_area(chunk->bits, end_bit, 0,
diff --git a/lib/idr.c b/lib/idr.c
index c1a206901761..7f1a4f0acf50 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -602,7 +602,7 @@ void *idr_get_next(struct idr *idp, int *nextidp)
 	/* find first ent */
 	n = idp->layers * IDR_BITS;
 	max = 1 << n;
-	p = rcu_dereference(idp->top);
+	p = rcu_dereference_raw(idp->top);
 	if (!p)
 		return NULL;
 
@@ -610,7 +610,7 @@ void *idr_get_next(struct idr *idp, int *nextidp)
 		while (n > 0 && p) {
 			n -= IDR_BITS;
 			*paa++ = p;
-			p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]);
+			p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
 		}
 
 		if (p) {
diff --git a/lib/lmb.c b/lib/lmb.c
deleted file mode 100644
index b1fc52606524..000000000000
--- a/lib/lmb.c
+++ /dev/null
@@ -1,541 +0,0 @@
-/*
- * 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 <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/bitops.h>
-#include <linux/lmb.h>
-
-#define LMB_ALLOC_ANYWHERE	0
-
-struct lmb lmb;
-
-static int lmb_debug;
-
-static int __init early_lmb(char *p)
-{
-	if (p && strstr(p, "debug"))
-		lmb_debug = 1;
-	return 0;
-}
-early_param("lmb", early_lmb);
-
-static void lmb_dump(struct lmb_region *region, char *name)
-{
-	unsigned long long base, size;
-	int i;
-
-	pr_info(" %s.cnt  = 0x%lx\n", name, region->cnt);
-
-	for (i = 0; i < region->cnt; i++) {
-		base = region->region[i].base;
-		size = region->region[i].size;
-
-		pr_info(" %s[0x%x]\t0x%016llx - 0x%016llx, 0x%llx bytes\n",
-		    name, i, base, base + size - 1, size);
-	}
-}
-
-void lmb_dump_all(void)
-{
-	if (!lmb_debug)
-		return;
-
-	pr_info("LMB configuration:\n");
-	pr_info(" rmo_size    = 0x%llx\n", (unsigned long long)lmb.rmo_size);
-	pr_info(" memory.size = 0x%llx\n", (unsigned long long)lmb.memory.size);
-
-	lmb_dump(&lmb.memory, "memory");
-	lmb_dump(&lmb.reserved, "reserved");
-}
-
-static unsigned long lmb_addrs_overlap(u64 base1, u64 size1, u64 base2,
-					u64 size2)
-{
-	return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
-}
-
-static long lmb_addrs_adjacent(u64 base1, u64 size1, u64 base2, u64 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)
-{
-	u64 base1 = rgn->region[r1].base;
-	u64 size1 = rgn->region[r1].size;
-	u64 base2 = rgn->region[r2].base;
-	u64 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 __init lmb_init(void)
-{
-	/* 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;
-
-	/* Ditto. */
-	lmb.reserved.region[0].base = 0;
-	lmb.reserved.region[0].size = 0;
-	lmb.reserved.cnt = 1;
-}
-
-void __init lmb_analyze(void)
-{
-	int i;
-
-	lmb.memory.size = 0;
-
-	for (i = 0; i < lmb.memory.cnt; i++)
-		lmb.memory.size += lmb.memory.region[i].size;
-}
-
-static long lmb_add_region(struct lmb_region *rgn, u64 base, u64 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++) {
-		u64 rgnbase = rgn->region[i].base;
-		u64 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;
-}
-
-long lmb_add(u64 base, u64 size)
-{
-	struct lmb_region *_rgn = &lmb.memory;
-
-	/* On pSeries LPAR systems, the first LMB is our RMO region. */
-	if (base == 0)
-		lmb.rmo_size = size;
-
-	return lmb_add_region(_rgn, base, size);
-
-}
-
-static long __lmb_remove(struct lmb_region *rgn, u64 base, u64 size)
-{
-	u64 rgnbegin, rgnend;
-	u64 end = base + size;
-	int i;
-
-	rgnbegin = rgnend = 0; /* supress gcc warnings */
-
-	/* Find the region where (base, size) belongs to */
-	for (i=0; i < rgn->cnt; i++) {
-		rgnbegin = rgn->region[i].base;
-		rgnend = rgnbegin + rgn->region[i].size;
-
-		if ((rgnbegin <= base) && (end <= rgnend))
-			break;
-	}
-
-	/* Didn't find the region */
-	if (i == rgn->cnt)
-		return -1;
-
-	/* Check to see if we are removing entire region */
-	if ((rgnbegin == base) && (rgnend == end)) {
-		lmb_remove_region(rgn, i);
-		return 0;
-	}
-
-	/* Check to see if region is matching at the front */
-	if (rgnbegin == base) {
-		rgn->region[i].base = end;
-		rgn->region[i].size -= size;
-		return 0;
-	}
-
-	/* Check to see if the region is matching at the end */
-	if (rgnend == end) {
-		rgn->region[i].size -= size;
-		return 0;
-	}
-
-	/*
-	 * We need to split the entry -  adjust the current one to the
-	 * beginging of the hole and add the region after hole.
-	 */
-	rgn->region[i].size = base - rgn->region[i].base;
-	return lmb_add_region(rgn, end, rgnend - end);
-}
-
-long lmb_remove(u64 base, u64 size)
-{
-	return __lmb_remove(&lmb.memory, base, size);
-}
-
-long __init lmb_free(u64 base, u64 size)
-{
-	return __lmb_remove(&lmb.reserved, base, size);
-}
-
-long __init lmb_reserve(u64 base, u64 size)
-{
-	struct lmb_region *_rgn = &lmb.reserved;
-
-	BUG_ON(0 == size);
-
-	return lmb_add_region(_rgn, base, size);
-}
-
-long lmb_overlaps_region(struct lmb_region *rgn, u64 base, u64 size)
-{
-	unsigned long i;
-
-	for (i = 0; i < rgn->cnt; i++) {
-		u64 rgnbase = rgn->region[i].base;
-		u64 rgnsize = rgn->region[i].size;
-		if (lmb_addrs_overlap(base, size, rgnbase, rgnsize))
-			break;
-	}
-
-	return (i < rgn->cnt) ? i : -1;
-}
-
-static u64 lmb_align_down(u64 addr, u64 size)
-{
-	return addr & ~(size - 1);
-}
-
-static u64 lmb_align_up(u64 addr, u64 size)
-{
-	return (addr + (size - 1)) & ~(size - 1);
-}
-
-static u64 __init lmb_alloc_nid_unreserved(u64 start, u64 end,
-					   u64 size, u64 align)
-{
-	u64 base, res_base;
-	long j;
-
-	base = lmb_align_down((end - size), align);
-	while (start <= base) {
-		j = lmb_overlaps_region(&lmb.reserved, base, size);
-		if (j < 0) {
-			/* this area isn't reserved, take it */
-			if (lmb_add_region(&lmb.reserved, base, size) < 0)
-				base = ~(u64)0;
-			return base;
-		}
-		res_base = lmb.reserved.region[j].base;
-		if (res_base < size)
-			break;
-		base = lmb_align_down(res_base - size, align);
-	}
-
-	return ~(u64)0;
-}
-
-static u64 __init lmb_alloc_nid_region(struct lmb_property *mp,
-				       u64 (*nid_range)(u64, u64, int *),
-				       u64 size, u64 align, int nid)
-{
-	u64 start, end;
-
-	start = mp->base;
-	end = start + mp->size;
-
-	start = lmb_align_up(start, align);
-	while (start < end) {
-		u64 this_end;
-		int this_nid;
-
-		this_end = nid_range(start, end, &this_nid);
-		if (this_nid == nid) {
-			u64 ret = lmb_alloc_nid_unreserved(start, this_end,
-							   size, align);
-			if (ret != ~(u64)0)
-				return ret;
-		}
-		start = this_end;
-	}
-
-	return ~(u64)0;
-}
-
-u64 __init lmb_alloc_nid(u64 size, u64 align, int nid,
-			 u64 (*nid_range)(u64 start, u64 end, int *nid))
-{
-	struct lmb_region *mem = &lmb.memory;
-	int i;
-
-	BUG_ON(0 == size);
-
-	size = lmb_align_up(size, align);
-
-	for (i = 0; i < mem->cnt; i++) {
-		u64 ret = lmb_alloc_nid_region(&mem->region[i],
-					       nid_range,
-					       size, align, nid);
-		if (ret != ~(u64)0)
-			return ret;
-	}
-
-	return lmb_alloc(size, align);
-}
-
-u64 __init lmb_alloc(u64 size, u64 align)
-{
-	return lmb_alloc_base(size, align, LMB_ALLOC_ANYWHERE);
-}
-
-u64 __init lmb_alloc_base(u64 size, u64 align, u64 max_addr)
-{
-	u64 alloc;
-
-	alloc = __lmb_alloc_base(size, align, max_addr);
-
-	if (alloc == 0)
-		panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
-		      (unsigned long long) size, (unsigned long long) max_addr);
-
-	return alloc;
-}
-
-u64 __init __lmb_alloc_base(u64 size, u64 align, u64 max_addr)
-{
-	long i, j;
-	u64 base = 0;
-	u64 res_base;
-
-	BUG_ON(0 == size);
-
-	size = lmb_align_up(size, align);
-
-	/* On some platforms, make sure we allocate lowmem */
-	/* Note that LMB_REAL_LIMIT may be LMB_ALLOC_ANYWHERE */
-	if (max_addr == LMB_ALLOC_ANYWHERE)
-		max_addr = LMB_REAL_LIMIT;
-
-	for (i = lmb.memory.cnt - 1; i >= 0; i--) {
-		u64 lmbbase = lmb.memory.region[i].base;
-		u64 lmbsize = lmb.memory.region[i].size;
-
-		if (lmbsize < size)
-			continue;
-		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 (base && lmbbase <= base) {
-			j = lmb_overlaps_region(&lmb.reserved, base, size);
-			if (j < 0) {
-				/* this area isn't reserved, take it */
-				if (lmb_add_region(&lmb.reserved, base, size) < 0)
-					return 0;
-				return base;
-			}
-			res_base = lmb.reserved.region[j].base;
-			if (res_base < size)
-				break;
-			base = lmb_align_down(res_base - size, align);
-		}
-	}
-	return 0;
-}
-
-/* You must call lmb_analyze() before this. */
-u64 __init lmb_phys_mem_size(void)
-{
-	return lmb.memory.size;
-}
-
-u64 lmb_end_of_DRAM(void)
-{
-	int idx = lmb.memory.cnt - 1;
-
-	return (lmb.memory.region[idx].base + lmb.memory.region[idx].size);
-}
-
-/* You must call lmb_analyze() after this. */
-void __init lmb_enforce_memory_limit(u64 memory_limit)
-{
-	unsigned long i;
-	u64 limit;
-	struct lmb_property *p;
-
-	if (!memory_limit)
-		return;
-
-	/* Truncate the lmb regions to satisfy the memory limit. */
-	limit = memory_limit;
-	for (i = 0; i < lmb.memory.cnt; i++) {
-		if (limit > lmb.memory.region[i].size) {
-			limit -= lmb.memory.region[i].size;
-			continue;
-		}
-
-		lmb.memory.region[i].size = limit;
-		lmb.memory.cnt = i + 1;
-		break;
-	}
-
-	if (lmb.memory.region[0].size < lmb.rmo_size)
-		lmb.rmo_size = lmb.memory.region[0].size;
-
-	memory_limit = lmb_end_of_DRAM();
-
-	/* And truncate any reserves above the limit also. */
-	for (i = 0; i < lmb.reserved.cnt; i++) {
-		p = &lmb.reserved.region[i];
-
-		if (p->base > memory_limit)
-			p->size = 0;
-		else if ((p->base + p->size) > memory_limit)
-			p->size = memory_limit - p->base;
-
-		if (p->size == 0) {
-			lmb_remove_region(&lmb.reserved, i);
-			i--;
-		}
-	}
-}
-
-int __init lmb_is_reserved(u64 addr)
-{
-	int i;
-
-	for (i = 0; i < lmb.reserved.cnt; i++) {
-		u64 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;
-}
-
-int lmb_is_region_reserved(u64 base, u64 size)
-{
-	return lmb_overlaps_region(&lmb.reserved, base, size);
-}
-
-/*
- * Given a <base, len>, find which memory regions belong to this range.
- * Adjust the request and return a contiguous chunk.
- */
-int lmb_find(struct lmb_property *res)
-{
-	int i;
-	u64 rstart, rend;
-
-	rstart = res->base;
-	rend = rstart + res->size - 1;
-
-	for (i = 0; i < lmb.memory.cnt; i++) {
-		u64 start = lmb.memory.region[i].base;
-		u64 end = start + lmb.memory.region[i].size - 1;
-
-		if (start > rend)
-			return -1;
-
-		if ((end >= rstart) && (start < rend)) {
-			/* adjust the request */
-			if (rstart < start)
-				rstart = start;
-			if (rend > end)
-				rend = end;
-			res->base = rstart;
-			res->size = rend - rstart + 1;
-			return 0;
-		}
-	}
-	return -1;
-}
diff --git a/lib/rbtree.c b/lib/rbtree.c
index 15e10b1afdd2..4693f79195d3 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -44,11 +44,6 @@ static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
 	else
 		root->rb_node = right;
 	rb_set_parent(node, right);
-
-	if (root->augment_cb) {
-		root->augment_cb(node);
-		root->augment_cb(right);
-	}
 }
 
 static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
@@ -72,20 +67,12 @@ static void __rb_rotate_right(struct rb_node *node, struct rb_root *root)
 	else
 		root->rb_node = left;
 	rb_set_parent(node, left);
-
-	if (root->augment_cb) {
-		root->augment_cb(node);
-		root->augment_cb(left);
-	}
 }
 
 void rb_insert_color(struct rb_node *node, struct rb_root *root)
 {
 	struct rb_node *parent, *gparent;
 
-	if (root->augment_cb)
-		root->augment_cb(node);
-
 	while ((parent = rb_parent(node)) && rb_is_red(parent))
 	{
 		gparent = rb_parent(parent);
@@ -240,15 +227,12 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
 	else
 	{
 		struct rb_node *old = node, *left;
-		int old_parent_cb = 0;
-		int successor_parent_cb = 0;
 
 		node = node->rb_right;
 		while ((left = node->rb_left) != NULL)
 			node = left;
 
 		if (rb_parent(old)) {
-			old_parent_cb = 1;
 			if (rb_parent(old)->rb_left == old)
 				rb_parent(old)->rb_left = node;
 			else
@@ -263,10 +247,8 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
 		if (parent == old) {
 			parent = node;
 		} else {
-			successor_parent_cb = 1;
 			if (child)
 				rb_set_parent(child, parent);
-
 			parent->rb_left = child;
 
 			node->rb_right = old->rb_right;
@@ -277,24 +259,6 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
 		node->rb_left = old->rb_left;
 		rb_set_parent(old->rb_left, node);
 
-		if (root->augment_cb) {
-			/*
-			 * Here, three different nodes can have new children.
-			 * The parent of the successor node that was selected
-			 * to replace the node to be erased.
-			 * The node that is getting erased and is now replaced
-			 * by its successor.
-			 * The parent of the node getting erased-replaced.
-			 */
-			if (successor_parent_cb)
-				root->augment_cb(parent);
-
-			root->augment_cb(node);
-
-			if (old_parent_cb)
-				root->augment_cb(rb_parent(old));
-		}
-
 		goto color;
 	}
 
@@ -303,19 +267,15 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
 
 	if (child)
 		rb_set_parent(child, parent);
-
-	if (parent) {
+	if (parent)
+	{
 		if (parent->rb_left == node)
 			parent->rb_left = child;
 		else
 			parent->rb_right = child;
-
-		if (root->augment_cb)
-			root->augment_cb(parent);
-
-	} else {
-		root->rb_node = child;
 	}
+	else
+		root->rb_node = child;
 
  color:
 	if (color == RB_BLACK)
@@ -323,6 +283,74 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
 }
 EXPORT_SYMBOL(rb_erase);
 
+static void rb_augment_path(struct rb_node *node, rb_augment_f func, void *data)
+{
+	struct rb_node *parent;
+
+up:
+	func(node, data);
+	parent = rb_parent(node);
+	if (!parent)
+		return;
+
+	if (node == parent->rb_left && parent->rb_right)
+		func(parent->rb_right, data);
+	else if (parent->rb_left)
+		func(parent->rb_left, data);
+
+	node = parent;
+	goto up;
+}
+
+/*
+ * after inserting @node into the tree, update the tree to account for
+ * both the new entry and any damage done by rebalance
+ */
+void rb_augment_insert(struct rb_node *node, rb_augment_f func, void *data)
+{
+	if (node->rb_left)
+		node = node->rb_left;
+	else if (node->rb_right)
+		node = node->rb_right;
+
+	rb_augment_path(node, func, data);
+}
+
+/*
+ * before removing the node, find the deepest node on the rebalance path
+ * that will still be there after @node gets removed
+ */
+struct rb_node *rb_augment_erase_begin(struct rb_node *node)
+{
+	struct rb_node *deepest;
+
+	if (!node->rb_right && !node->rb_left)
+		deepest = rb_parent(node);
+	else if (!node->rb_right)
+		deepest = node->rb_left;
+	else if (!node->rb_left)
+		deepest = node->rb_right;
+	else {
+		deepest = rb_next(node);
+		if (deepest->rb_right)
+			deepest = deepest->rb_right;
+		else if (rb_parent(deepest) != node)
+			deepest = rb_parent(deepest);
+	}
+
+	return deepest;
+}
+
+/*
+ * after removal, update the tree to account for the removed entry
+ * and any rebalance damage.
+ */
+void rb_augment_erase_end(struct rb_node *node, rb_augment_f func, void *data)
+{
+	if (node)
+		rb_augment_path(node, func, data);
+}
+
 /*
  * This function returns the first node (in sort order) of the tree.
  */