armv8/ls2085a: Expose all DDR region(s) to Linux

This patch allows u-boot to expose the complete DDR region(s) to Linux
(after subtracting the memory hidden via MEM_TOP_HIDE mechanism).

This allows the u-boot to support the 48-bit VA support provided by
ARM64 Linux in flavors 3.18 and above, by passing the appropriate
'memory' DTS nodes.

Signed-off-by: Bhupesh Sharma <bhupesh.sharma at freescale.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar at freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>

2 files changed, 20 insertions, 6 deletions

diff --git a/board/freescale/ls2085a/README b/board/freescale/ls2085a/README
index b7023e1d48..bc1d0bb4a7 100644
--- a/board/freescale/ls2085a/README
+++ b/board/freescale/ls2085a/README
@@ -14,3 +14,14 @@ Memory map from core's view
 
 Other addresses are either reserved, or not used directly by u-boot.
 This list should be updated when more addresses are used.
+
+Booting Linux flavors which do not support 48-bit VA (< Linux 3.18)
+-------------------------------------------------------------------
+One needs to use appropriate bootargs to boot Linux flavors which do
+not support 48-bit VA (for e.g. < Linux 3.18) by appending mem=2048M, as shown
+below:
+
+=> setenv bootargs 'console=ttyS1,115200 root=/dev/ram
+   earlycon=uart8250,mmio,0x21c0600,115200 default_hugepagesz=2m hugepagesz=2m
+   hugepages=16 mem=2048M'
+
diff --git a/board/freescale/ls2085a/ls2085a.c b/board/freescale/ls2085a/ls2085a.c
index dd0acf23b2..e43dd4c9af 100644
--- a/board/freescale/ls2085a/ls2085a.c
+++ b/board/freescale/ls2085a/ls2085a.c
@@ -127,15 +127,18 @@ void fdt_fixup_board_enet(void *fdt)
 #ifdef CONFIG_OF_BOARD_SETUP
 int ft_board_setup(void *blob, bd_t *bd)
 {
-	phys_addr_t base;
-	phys_size_t size;
+	u64 base[CONFIG_NR_DRAM_BANKS];
+	u64 size[CONFIG_NR_DRAM_BANKS];
 
 	ft_cpu_setup(blob, bd);
 
-	/* limit the memory size to bank 1 until Linux can handle 40-bit PA */
-	base = getenv_bootm_low();
-	size = getenv_bootm_size();
-	fdt_fixup_memory(blob, (u64)base, (u64)size);
+	/* fixup DT for the two GPP DDR banks */
+	base[0] = gd->bd->bi_dram[0].start;
+	size[0] = gd->bd->bi_dram[0].size;
+	base[1] = gd->bd->bi_dram[1].start;
+	size[1] = gd->bd->bi_dram[1].size;
+
+	fdt_fixup_memory_banks(blob, base, size, 2);
 
 #ifdef CONFIG_FSL_MC_ENET
 	fdt_fixup_board_enet(blob);