lmb: Reinstate access to memory above ram_top

Revert commit eb052cbb896f ("lmb: add and reserve memory above ram_top")
and commit 1a48b0be93d4 ("lmb: prohibit allocations above ram_top even from
same bank"). These are based on incorrect premise of the first commit, that
"U-Boot does not use memory above ram_top". While U-Boot itself indeed does
not and should not use memory above ram_top, user can perfectly well use
that memory from the U-Boot shell, for example to load content in there.

Currently, attempt to use that memory to load large image using TFTP ends
with "TFTP error: trying to overwrite reserved memory...". With this change
in place, the memory can be used again.

Fixes: eb052cbb896f ("lmb: add and reserve memory above ram_top")
Fixes: 1a48b0be93d4 ("lmb: prohibit allocations above ram_top even from same bank")
Reported-by: Yuya Hamamachi <[email protected]>
Signed-off-by: Marek Vasut <[email protected]>

1 files changed, 1 insertions, 16 deletions

diff --git a/lib/lmb.c b/lib/lmb.c
index e2d9fe86c14..8f12c6ad8e5 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -611,7 +611,6 @@ static __maybe_unused void lmb_reserve_common_spl(void)
 static void lmb_add_memory(void)
 {
 	int i;
-	phys_addr_t bank_end;
 	phys_size_t size;
 	u64 ram_top = gd->ram_top;
 	struct bd_info *bd = gd->bd;
@@ -625,23 +624,9 @@ static void lmb_add_memory(void)
 
 	for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
 		size = bd->bi_dram[i].size;
-		bank_end = bd->bi_dram[i].start + size;
 
-		if (size) {
+		if (size)
 			lmb_add(bd->bi_dram[i].start, size);
-
-			/*
-			 * Reserve memory above ram_top as
-			 * no-overwrite so that it cannot be
-			 * allocated
-			 */
-			if (bd->bi_dram[i].start >= ram_top)
-				lmb_reserve(bd->bi_dram[i].start, size,
-					    LMB_NOOVERWRITE);
-			else if (bank_end > ram_top)
-				lmb_reserve(ram_top, bank_end - ram_top,
-					    LMB_NOOVERWRITE);
-		}
 	}
 }