[PATCH] lmb: remove overlapping region with next range

[Heinrich Schuchardt]

Am 24. September 2023 13:18:32 MESZ schrieb Udit Kumar <u-kumar1 at ti.com>:
>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*/

Assumption

Regards Heinrich

>+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++;
> 		}
> 	}
>