[U-Boot] [PATCH v10 10/10] arm: bootm: fix sp detection at end of address range

[Simon Goldschmidt]

This fixes  'arch_lmb_reserve()' for ARM that tries to detect in which
DRAM bank 'sp' is in.

This code failed if a bank was at the end of physical address range
(i.e. size + length overflowed to 0).

To fix this, calculate 'bank_end' as 'size + length - 1' so that such
banks end at 0xffffffff, not 0.

Fixes: 15751403b6 ("ARM: bootm: don't assume sp is in DRAM bank 0")
Reported-by: Frank Wunderlich <frank-w at public-files.de>
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>
Reviewed-by: Stephen Warren <swarren at nvidia.com>
---

Changes in v10: None
Changes in v9:
- fix compile error in arch/arm/lib/bootm.c

Changes in v8:
- this patch is new in v8

Changes in v7: None
Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v2: None

 arch/arm/lib/bootm.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index c3c1d2fdfa..329f20c2bf 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -64,13 +64,15 @@ void arch_lmb_reserve(struct lmb *lmb)
 	/* adjust sp by 4K to be safe */
 	sp -= 4096;
 	for (bank = 0; bank < CONFIG_NR_DRAM_BANKS; bank++) {
-		if (sp < gd->bd->bi_dram[bank].start)
+		if (!gd->bd->bi_dram[bank].size ||
+		    sp < gd->bd->bi_dram[bank].start)
 			continue;
+		/* Watch out for RAM at end of address space! */
 		bank_end = gd->bd->bi_dram[bank].start +
-			gd->bd->bi_dram[bank].size;
-		if (sp >= bank_end)
+			gd->bd->bi_dram[bank].size - 1;
+		if (sp > bank_end)
 			continue;
-		lmb_reserve(lmb, sp, bank_end - sp);
+		lmb_reserve(lmb, sp, bank_end - sp + 1);
 		break;
 	}
 }
-- 
2.17.1