[PATCH v2 2/6] lmb: handle scenario of encompassing overlap

[Sughosh Ganu]

The lmb_fix_over_lap_regions() function is called if the added region
overlaps with an existing region. The function then fixes the overlap
and removes the redundant region. However, it makes certain
assumptions. One assumption is that the overlap would not encompass
the existing region. Another assumption is that the overlap only
occurs between two regions -- the scenario of the added region
overlapping multiple existing regions is not being handled. Handle
these cases by instead calling lmb_resize_regions(). Also remove the
now superfluous lmb_fix_over_lap_regions().

Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
---
Changes since V1:
* Use lmb_resize_regions() to fix the overlap instead of
  lmb_fix_over_lap_regions().
* Remove the now superfluous lmb_fix_over_lap_regions().


Note: To be applied after an A-b/R-b/T-b from the original author of
      lmb_fix_over_lap_regions().


 lib/lmb.c | 30 +++++++++---------------------
 1 file changed, 9 insertions(+), 21 deletions(-)

diff --git a/lib/lmb.c b/lib/lmb.c
index d7d2c8c6dfd..207f059ceb9 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -100,25 +100,6 @@ static void lmb_coalesce_regions(struct alist *lmb_rgn_lst, unsigned long r1,
 	lmb_remove_region(lmb_rgn_lst, r2);
 }
 
-/*Assumption : base addr of region 1 < base addr of region 2*/
-static void lmb_fix_over_lap_regions(struct alist *lmb_rgn_lst,
-				     unsigned long r1, unsigned long r2)
-{
-	struct lmb_region *rgn = lmb_rgn_lst->data;
-
-	phys_addr_t base1 = rgn[r1].base;
-	phys_size_t size1 = rgn[r1].size;
-	phys_addr_t base2 = rgn[r2].base;
-	phys_size_t size2 = rgn[r2].size;
-
-	if (base1 + size1 > base2 + size2) {
-		printf("This will not be a case any time\n");
-		return;
-	}
-	rgn[r1].size = base2 + size2 - base1;
-	lmb_remove_region(lmb_rgn_lst, r2);
-}
-
 static long lmb_resize_regions(struct alist *lmb_rgn_lst,
 			       unsigned long idx_start,
 			       phys_addr_t base, phys_size_t size)
@@ -239,8 +220,15 @@ static long lmb_add_region_flags(struct alist *lmb_rgn_lst, phys_addr_t base,
 				lmb_coalesce_regions(lmb_rgn_lst, i, i + 1);
 				coalesced++;
 			} else if (lmb_regions_overlap(lmb_rgn_lst, i, i + 1)) {
-				/* fix overlapping area */
-				lmb_fix_over_lap_regions(lmb_rgn_lst, i, i + 1);
+				/* fix overlapping areas */
+				phys_addr_t rgnbase = rgn[i].base;
+				phys_size_t rgnsize = rgn[i].size;
+
+				ret = lmb_resize_regions(lmb_rgn_lst, i,
+							 rgnbase, rgnsize);
+				if (ret < 0)
+					return -1;
+
 				coalesced++;
 			}
 		}
-- 
2.34.1