MIPS: Add helper function to allow platforms to point at a DTB.

Add __dt_setup_arch() that can be called to load a builtin DT.
Additionally we add a macro to allow loading a specific symbol
from the __dtb_* section.

Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3715/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/mips/include/asm/prom.h b/arch/mips/include/asm/prom.h
index 40ed25952e6b..7206d445bab8 100644
--- a/arch/mips/include/asm/prom.h
+++ b/arch/mips/include/asm/prom.h
@@ -36,6 +36,17 @@ static inline unsigned long pci_address_to_pio(phys_addr_t address)
 }
 #define pci_address_to_pio pci_address_to_pio
 
+struct boot_param_header;
+
+extern void __dt_setup_arch(struct boot_param_header *bph);
+
+#define dt_setup_arch(sym)                                              \
+({                                                                      \
+        extern struct boot_param_header __dtb_##sym##_begin;            \
+                                                                        \
+        __dt_setup_arch(&__dtb_##sym##_begin);                          \
+})
+
 #else /* CONFIG_OF */
 static inline void device_tree_init(void) { }
 #endif /* CONFIG_OF */