[PATCH 2/2] rockchip: sdram: add dram bank with usable memory beyond 4GB

[Jonas Karlman]

Add a second dram bank of usable memory beyond the blob of space for
peripheral near 4GB. Any memory that exists beyond the 4GB mark is added
to the second bank.

Signed-off-by: Jonas Karlman <jonas at kwiboo.se>
---
 arch/arm/mach-rockchip/sdram.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-rockchip/sdram.c b/arch/arm/mach-rockchip/sdram.c
index 7c12112799..2007064f0a 100644
--- a/arch/arm/mach-rockchip/sdram.c
+++ b/arch/arm/mach-rockchip/sdram.c
@@ -37,13 +37,19 @@ struct tos_parameter_t {
 
 int dram_init_banksize(void)
 {
-	size_t top = min((unsigned long)(gd->ram_size + CONFIG_SYS_SDRAM_BASE),
-			 (unsigned long)(gd->ram_top));
+	size_t ram_top = (unsigned long)(gd->ram_size + CONFIG_SYS_SDRAM_BASE);
+	size_t top = min((unsigned long)ram_top, (unsigned long)(gd->ram_top));
 
 #ifdef CONFIG_ARM64
 	/* Reserve 0x200000 for ATF bl31 */
 	gd->bd->bi_dram[0].start = 0x200000;
 	gd->bd->bi_dram[0].size = top - gd->bd->bi_dram[0].start;
+
+	/* Add usable memory beyond the blob of space for peripheral near 4GB */
+	if (ram_top > SZ_4G && top < SZ_4G) {
+		gd->bd->bi_dram[1].start = SZ_4G;
+		gd->bd->bi_dram[1].size = ram_top - gd->bd->bi_dram[1].start;
+	}
 #else
 #ifdef CONFIG_SPL_OPTEE_IMAGE
 	struct tos_parameter_t *tos_parameter;
@@ -181,7 +187,7 @@ size_t rockchip_sdram_size(phys_addr_t reg)
 	 *   2. update board_get_usable_ram_top() and dram_init_banksize()
 	 *   to reserve memory for peripheral space after previous update.
 	 */
-	if (size_mb > (SDRAM_MAX_SIZE >> 20))
+	if (!IS_ENABLED(CONFIG_ARM64) && size_mb > (SDRAM_MAX_SIZE >> 20))
 		size_mb = (SDRAM_MAX_SIZE >> 20);
 
 	return (size_t)size_mb << 20;
-- 
2.39.0