MIPS: kexec: Use prepare method from Generic for UHI platforms

Out-of-tree platforms may not be based on Generic as shown in customer
communication. Share the prepare method with all using UHI boot protocol,
and put into machine_kexec.c.

The benefit is that, when having kexec_args related problems, developers
will naturally look into machine_kexec.c, where "CONFIG_UHI_BOOT" will be
found, prompting them to add "select UHI_BOOT" to the platform Kconfig. It
would otherwise require a lot debugging or online searching to be aware
that the solution is in Generic code.

Tested-by: Rachel Mozes <rachel.mozes@intel.com>
Reported-by: Rachel Mozes <rachel.mozes@intel.com>
Signed-off-by: Dengcheng Zhu <dzhu@wavecomp.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20569/
Cc: pburton@wavecomp.com
Cc: ralf@linux-mips.org
Cc: linux-mips@linux-mips.org

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index f744d25f7423..ce55c3c2d10d 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -133,6 +133,7 @@ config MIPS_GENERIC
         select USB_UHCI_BIG_ENDIAN_DESC if CPU_BIG_ENDIAN
         select USB_UHCI_BIG_ENDIAN_MMIO if CPU_BIG_ENDIAN
         select USE_OF
+        select UHI_BOOT
         help
           Select this to build a kernel which aims to support multiple boards,
           generally using a flattened device tree passed from the bootloader
@@ -2899,6 +2900,9 @@ config USE_OF
         select OF_EARLY_FLATTREE
         select IRQ_DOMAIN
 
+config UHI_BOOT
+        bool
+
 config BUILTIN_DTB
         bool