[PATCH v1 4/9] stm32mp: dram_init: Limit DDR usage under 4GB boundary for STM32MP

[Patrice Chotard]

Limit DDR usage under 4GB boundary on STM32MP regardless of
memory size declared in device tree.

Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
---

 arch/arm/mach-stm32mp/dram_init.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-stm32mp/dram_init.c b/arch/arm/mach-stm32mp/dram_init.c
index cb35ed60ca1..fb1208fc5d5 100644
--- a/arch/arm/mach-stm32mp/dram_init.c
+++ b/arch/arm/mach-stm32mp/dram_init.c
@@ -52,9 +52,15 @@ phys_addr_t board_get_usable_ram_top(phys_size_t total_size)
 	if (!total_size)
 		return gd->ram_top;
 
+	/*
+	 * make sure U-Boot uses address space below 4GB boundaries even
+	 * if the effective available memory is bigger
+	 */
+	gd->ram_top = clamp_val(gd->ram_top, 0, SZ_4G - 1);
+
 	/* found enough not-reserved memory to relocated U-Boot */
 	lmb_init(&lmb);
-	lmb_add(&lmb, gd->ram_base, get_effective_memsize());
+	lmb_add(&lmb, gd->ram_base, gd->ram_top - gd->ram_base);
 	boot_fdt_add_mem_rsv_regions(&lmb, (void *)gd->fdt_blob);
 	/* add 8M for reserved memory for display, fdt, gd,... */
 	size = ALIGN(SZ_8M + CONFIG_SYS_MALLOC_LEN + total_size, MMU_SECTION_SIZE),
-- 
2.25.1