[PATCH] xilinx: Handle board_get_usable_ram_top(0) properly

[Michal Simek]

board_get_usable_ram_top() was designed for getting the top most location
for U-Boot allocation that's why function itself supports via total_size
parameter to find out where the right location for U-Boot is.
But function itself is also reused by different (EFI) which is passing
total_size as 0 to find out where the usable ram top is. For this case
doesn't make sense (a waste time) to call any lmb functions.
That's why simply return gd->ram_top.

And gd->ram_top is filled already based on previous call for U-Boot iself.
The same solution is also used by stm32mp by commit 92b611e8b003 ("stm32mp:
correctly handle board_get_usable_ram_top(0)") and commit c8510e397fad
("stm32mp: Fix board_get_usable_ram_top()").

Signed-off-by: Michal Simek <michal.simek at amd.com>
---

 board/xilinx/versal/board.c  | 3 +++
 board/xilinx/zynqmp/zynqmp.c | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/board/xilinx/versal/board.c b/board/xilinx/versal/board.c
index 2e2807eee463..a88f5bb177e2 100644
--- a/board/xilinx/versal/board.c
+++ b/board/xilinx/versal/board.c
@@ -256,6 +256,9 @@ ulong board_get_usable_ram_top(ulong total_size)
 	phys_addr_t reg;
 	struct lmb lmb;
 
+	if (!total_size)
+		return gd->ram_top;
+
 	/* found enough not-reserved memory to relocated U-Boot */
 	lmb_init(&lmb);
 	lmb_add(&lmb, gd->ram_base, gd->ram_size);
diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
index 41ecc9559c4b..e311aa772cce 100644
--- a/board/xilinx/zynqmp/zynqmp.c
+++ b/board/xilinx/zynqmp/zynqmp.c
@@ -516,6 +516,9 @@ ulong board_get_usable_ram_top(ulong total_size)
 	phys_addr_t reg;
 	struct lmb lmb;
 
+	if (!total_size)
+		return gd->ram_top;
+
 	if (!IS_ALIGNED((ulong)gd->fdt_blob, 0x8))
 		panic("Not 64bit aligned DT location: %p\n", gd->fdt_blob);
 
-- 
2.36.0