[PATCH] lmb: remove overlapping region with next range

[Udit Kumar]

In case of new memory range to be added is coalesced
with any already added non last lmb region.

And there is possibility that, then region in which new memory
range added is not adjacent to next region. But have some
sections are overlapping.

So along with adjacency check with next lmb region,
check for overlap should be done.

In case overlap  is found, adjust and merge these two lmb
region into one.

Reported-by: Suman Anna <s-anna at ti.com>
Signed-off-by: Udit Kumar <u-kumar1 at ti.com>
---
logs
https://gist.github.com/uditkumarti/5d08c34442235ad270cfa863792ebcdc
seqeunce : line 1 to 13
without fix : line 96-100
with fix : line 199-202

 lib/lmb.c | 37 +++++++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/lib/lmb.c b/lib/lmb.c
index b2c233edb6..2580d01d90 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -74,6 +74,16 @@ static long lmb_addrs_adjacent(phys_addr_t base1, phys_size_t size1,
 	return 0;
 }
 
+static long lmb_regions_overlap(struct lmb_region *rgn, unsigned long r1,
+				unsigned long r2)
+{
+	phys_addr_t base1 = rgn->region[r1].base;
+	phys_size_t size1 = rgn->region[r1].size;
+	phys_addr_t base2 = rgn->region[r2].base;
+	phys_size_t size2 = rgn->region[r2].size;
+
+	return lmb_addrs_overlap(base1, size1, base2, size2);
+}
 static long lmb_regions_adjacent(struct lmb_region *rgn, unsigned long r1,
 				 unsigned long r2)
 {
@@ -81,7 +91,6 @@ static long lmb_regions_adjacent(struct lmb_region *rgn, unsigned long r1,
 	phys_size_t size1 = rgn->region[r1].size;
 	phys_addr_t base2 = rgn->region[r2].base;
 	phys_size_t size2 = rgn->region[r2].size;
-
 	return lmb_addrs_adjacent(base1, size1, base2, size2);
 }
 
@@ -105,6 +114,23 @@ static void lmb_coalesce_regions(struct lmb_region *rgn, unsigned long r1,
 	lmb_remove_region(rgn, r2);
 }
 
+/*Assmptuon : base addr of region 1 < base addr of region 2*/
+static void lmb_fix_over_lap_regions(struct lmb_region *rgn, unsigned long r1,
+				     unsigned long r2)
+{
+	phys_addr_t base1 = rgn->region[r1].base;
+	phys_size_t size1 = rgn->region[r1].size;
+	phys_addr_t base2 = rgn->region[r2].base;
+	phys_size_t size2 = rgn->region[r2].size;
+
+	if (base1 + size1 > base2 + size2) {
+		printf("This will not be a case any time\n");
+		return;
+	}
+	rgn->region[r1].size = base2 + size2 - base1;
+	lmb_remove_region(rgn, r2);
+}
+
 void lmb_init(struct lmb *lmb)
 {
 #if IS_ENABLED(CONFIG_LMB_USE_MAX_REGIONS)
@@ -249,7 +275,6 @@ static long lmb_add_region_flags(struct lmb_region *rgn, phys_addr_t base,
 		phys_size_t rgnflags = rgn->region[i].flags;
 		phys_addr_t end = base + size - 1;
 		phys_addr_t rgnend = rgnbase + rgnsize - 1;
-
 		if (rgnbase <= base && end <= rgnend) {
 			if (flags == rgnflags)
 				/* Already have this region, so we're done */
@@ -278,10 +303,14 @@ static long lmb_add_region_flags(struct lmb_region *rgn, phys_addr_t base,
 		}
 	}
 
-	if ((i < rgn->cnt - 1) && lmb_regions_adjacent(rgn, i, i + 1)) {
-		if (rgn->region[i].flags == rgn->region[i + 1].flags) {
+	if (i < rgn->cnt - 1 && rgn->region[i].flags == rgn->region[i + 1].flags)  {
+		if (lmb_regions_adjacent(rgn, i, i + 1)) {
 			lmb_coalesce_regions(rgn, i, i + 1);
 			coalesced++;
+		} else if (lmb_regions_overlap(rgn, i, i + 1)) {
+			/* fix overlapping area */
+			lmb_fix_over_lap_regions(rgn, i, i + 1);
+			coalesced++;
 		}
 	}
 
-- 
2.34.1