[PATCH 1/1] board: toradex: Make A53 get RAM size from DT in K3 boards

[Suhaas Joshi]

`dram_init()` is called by R5 SPL and U-Boot, both. It starts by
computing the size of the RAM. In verdin-am62(p), it does so by calling
`get_ram_size()`. This function computes the size of the RAM by writing
over the RAM.

When R5 computes the size of the RAM, it does not update the DT with
this size. As a result, when A53 invokes `dram_init()` again, it has to
compute the size through `get_ram_size()` again.

Commit 13c54cf588d82 and 0c3a6f748c9 add firewall over ATF's and OPTEE's
regions. This firewall is added during the R5 SPL stage of boot. So when
A53 attempts to write over RAM in `get_ram_size()`, it writes over the
protected region. Since A53 is a non-secure core, this is blocked by the
firewall.

To fix this, do the following:
    * Implement `spl_perform_board_fixups()` function for verdin-am62
      and verdin-am62p. Make this function call `fixup_memory_node()`,
      which updates the DT.
    * Add an if-block in `dram_init()`, to ensure that only R5 is able
      to call `get_ram_size()`, and that A53 reads this size from the
      DT.

Signed-off-by: Suhaas Joshi <s-jo...@ti.com>
---
 board/toradex/verdin-am62/verdin-am62.c   | 10 ++++++++++
 board/toradex/verdin-am62p/verdin-am62p.c | 11 +++++++++++
 2 files changed, 21 insertions(+)

diff --git a/board/toradex/verdin-am62/verdin-am62.c 
b/board/toradex/verdin-am62/verdin-am62.c
index 069aa6c7909..1aa106afbd9 100644
--- a/board/toradex/verdin-am62/verdin-am62.c
+++ b/board/toradex/verdin-am62/verdin-am62.c
@@ -24,6 +24,9 @@ DECLARE_GLOBAL_DATA_PTR;
 
 int dram_init(void)
 {
+       if (!IS_ENABLED(CONFIG_CPU_V7R))
+               return fdtdec_setup_mem_size_base();
+
        gd->ram_size = get_ram_size((long *)CFG_SYS_SDRAM_BASE, 
CFG_SYS_SDRAM_SIZE);
 
        if (gd->ram_size < SZ_512M)
@@ -103,6 +106,13 @@ int board_late_init(void)
        return 0;
 }
 
+#if IS_ENABLED(CONFIG_XPL_BUILD)
+void spl_perform_board_fixups(struct spl_image_info *spl_image)
+{
+       fixup_memory_node(spl_image);
+}
+#endif
+
 #define CTRLMMR_USB0_PHY_CTRL          0x43004008
 #define CTRLMMR_USB1_PHY_CTRL          0x43004018
 #define CORE_VOLTAGE                   0x80000000
diff --git a/board/toradex/verdin-am62p/verdin-am62p.c 
b/board/toradex/verdin-am62p/verdin-am62p.c
index 7c631f380ff..12693c1a46b 100644
--- a/board/toradex/verdin-am62p/verdin-am62p.c
+++ b/board/toradex/verdin-am62p/verdin-am62p.c
@@ -18,6 +18,7 @@
 #include <k3-ddrss.h>
 #include <spl.h>
 #include <linux/sizes.h>
+#include <mach/k3-ddr.h>
 
 #include "../common/tdx-cfg-block.h"
 
@@ -57,6 +58,9 @@ static void read_hw_cfg(void)
 
 int dram_init(void)
 {
+       if (!IS_ENABLED(CONFIG_CPU_V7R))
+               return fdtdec_setup_mem_size_base();
+
        gd->ram_size = get_ram_size((long *)CFG_SYS_SDRAM_BASE, 
CFG_SYS_SDRAM_SIZE);
 
        if (gd->ram_size < SZ_1G)
@@ -132,6 +136,13 @@ int board_late_init(void)
        return 0;
 }
 
+#if IS_ENABLED(CONFIG_XPL_BUILD)
+void spl_perform_board_fixups(struct spl_image_info *spl_image)
+{
+       fixup_memory_node(spl_image);
+}
+#endif
+
 #define MCU_CTRL_LFXOSC_32K_BYPASS_VAL BIT(4)
 
 void spl_board_init(void)
-- 
2.34.1