[PATCH 13/46] riscv: reserved_mem: Implement the new processing order for reserved memory

[Oreoluwa Babatunde]

Call early_fdt_scan_reserved_mem() in place of
early_init_fdt_scan_reserved_mem() to carry out the first stage of the
reserved memory processing only.

The early_fdt_scan_reserved_mem() function is used to scan through the
DT and mark all the reserved memory regions as reserved or nomap as
needed, as well as allocate the memory required by the
dynamically-placed
reserved memory regions.

The second stage of the reserved memory processing is done by
fdt_init_reserved_mem(). This function is used to store the information
of the statically-placed reserved memory nodes in the reserved_mem
array as well as call the region specific initialization function on all
the stored reserved memory regions.

The call to fdt_init_reserved_mem() is placed after paging_init()
in preparation for the dynamic allocation of the reserved_mem array
using memblock. This is because memblock allocated memory is not
writable until after the page tables have been setup on the riscv
architecture.

Signed-off-by: Oreoluwa Babatunde <quic_obabatun@xxxxxxxxxxx>
---
 arch/riscv/kernel/setup.c | 3 +++
 arch/riscv/mm/init.c      | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 4f73c0ae44b2..ea4fbc8e0ea1 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -16,6 +16,7 @@
 #include <linux/sched.h>
 #include <linux/console.h>
 #include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/sched/task.h>
 #include <linux/smp.h>
 #include <linux/efi.h>
@@ -261,6 +262,8 @@ void __init setup_arch(char **cmdline_p)
 	efi_init();
 	paging_init();
 
+	fdt_init_reserved_mem();
+
 	/* Parse the ACPI tables for possible boot-time configuration */
 	acpi_boot_table_init();
 
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 32cad6a65ccd..32b168d6672b 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -264,7 +264,7 @@ static void __init setup_bootmem(void)
 	 * in the device tree, otherwise the allocation could end up in a
 	 * reserved region.
 	 */
-	early_init_fdt_scan_reserved_mem();
+	early_fdt_scan_reserved_mem();
 
 	/*
 	 * If DTB is built in, no need to reserve its memblock.
-- 
2.17.1