arm: bootm: fix sp detection at end of address range

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@public-files.de>
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>

diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index c3c1d2f..329f20c 100644 (file)
--- 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;
        }
 }