[PATCH] ARM: imx: imx8m: Fix board_get_usable_ram_top()

[Marek Vasut]

The 4 GiB boundary is at 0xffffffff+1 , not at 0x80000000, fix this.

The PHYS_SDRAM of i.MX8M is at 0x40000000 , so to restrict ram_top
below 4 GiB, the ram_top has to be set to 0xffffffff as it is not
an offset from the start of PHYS_SDRAM, but rather a physical address
marking the topmost allowed DRAM address.

Fixes: e27bddff4b9 ("imx8m: Restrict usable memory to space below 4G boundary")
Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Fabio Estevam <festevam at denx.de>
Cc: Frieder Schrempf <frieder.schrempf at kontron.de>
Cc: Peng Fan <peng.fan at nxp.com>
Cc: Stefano Babic <sbabic at denx.de>
---
 arch/arm/mach-imx/imx8m/soc.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-imx/imx8m/soc.c b/arch/arm/mach-imx/imx8m/soc.c
index 8171631db10..e7fe7c2fd88 100644
--- a/arch/arm/mach-imx/imx8m/soc.c
+++ b/arch/arm/mach-imx/imx8m/soc.c
@@ -331,7 +331,7 @@ phys_size_t get_effective_memsize(void)
 
 ulong board_get_usable_ram_top(ulong total_size)
 {
-	ulong top_addr = PHYS_SDRAM + gd->ram_size;
+	ulong top_addr;
 
 	/*
 	 * Some IPs have their accessible address space restricted by
@@ -339,8 +339,7 @@ ulong board_get_usable_ram_top(ulong total_size)
 	 * space below the 4G address boundary (which is 3GiB big),
 	 * even when the effective available memory is bigger.
 	 */
-	if (top_addr > 0x80000000)
-		top_addr = 0x80000000;
+	top_addr = clamp_val((u64)PHYS_SDRAM + gd->ram_size, 0, 0xffffffff);
 
 	/*
 	 * rom_pointer[0] stores the TEE memory start address.
-- 
2.35.1