From: Bin Meng [mailto:bmeng.cn@gmail.com] Sent: Wednesday, May 20, 2020 3:40 PM To: Rick Jian-Zhi Chen(陳建志); U-Boot Mailing List Cc: Bin Meng Subject: [PATCH 1/2] riscv: Avoid the reserved memory fixup if src and dst point to the same place

From: Bin Meng bin.meng@windriver.com

The copy of reserved memory node from source dtb to destination dtb can be avoided if they point to the same place. This is useful when OF_PRIOR_STAGE is used.

Signed-off-by: Bin Meng bin.meng@windriver.com

Reviewed-by: Rick Chen rick@andestech.com

arch/riscv/lib/fdt_fixup.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/lib/fdt_fixup.c b/arch/riscv/lib/fdt_fixup.c index 6db48ad..5f523f0 100644 --- a/arch/riscv/lib/fdt_fixup.c +++ b/arch/riscv/lib/fdt_fixup.c @@ -82,10 +82,9 @@ int riscv_fdt_copy_resv_mem_node(const void *src, void *dst)

• @fdt: Pointer to the device tree in which reserved memory node needs to be

•  added.
  

• • In RISC-V, any board compiled with OF_SEPARATE needs to copy the reserved
• • memory node from the device tree provided by the firmware to the device tree
• • used by U-Boot. This is a common function that individual board fixup
• • functions can invoke.

• • In RISC-V, any board needs to copy the reserved memory node from the
• device
• • tree provided by the firmware to the device tree used by U-Boot.
• This is a
• • common function that individual board fixup functions can invoke.
  • Return: 0 on success or error otherwise.
  */

@@ -95,6 +94,11 @@ int riscv_board_reserved_mem_fixup(void *fdt) void *src_fdt_addr;

    src_fdt_addr = map_sysmem(gd->arch.firmware_fdt_addr, 0);

•   /* avoid the copy if we are using the same device tree */
  

•   if (src_fdt_addr == fdt)
  

•           return 0;
  

•   err = riscv_fdt_copy_resv_mem_node(src_fdt_addr, fdt);
    if (err < 0)
            return err;
  

-- 2.7.4