[PATCH 26/46] powerpc: resrved_mem: Move fdt_init_reserved_mem() below unflatten_device_tree()

From: Oreoluwa Babatunde
Date: Fri Jan 26 2024 - 18:56:26 EST


The unflattened devicetree structure is available to be used not long
after the page tables have been set up on most architectures, and is
available even before that on other architectures.

Hence, move the call to fdt_init_reserved_mem() to after
unflatten_device_tree() is called so that the reserved memory nodes can
be accessed using the unflattened device tree APIs.

Using the unflattened devicetree APIs is more efficient than using the
flattened devicetree APIs.

Signed-off-by: Oreoluwa Babatunde <quic_obabatun@xxxxxxxxxxx>
---
arch/powerpc/kernel/prom.c | 2 --
arch/powerpc/kernel/setup-common.c | 3 +++
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 5f6307ea3069..3cf8213b114c 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -27,7 +27,6 @@
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
-#include <linux/of_reserved_mem.h>
#include <linux/libfdt.h>
#include <linux/cpu.h>
#include <linux/pgtable.h>
@@ -621,7 +620,6 @@ static void __init early_reserve_mem_dt(void)

early_init_fdt_reserve_self();
early_fdt_scan_reserved_mem();
- fdt_init_reserved_mem();

dt_root = of_get_flat_dt_root();

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 9b142b9d5187..96bd4c964943 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -32,6 +32,7 @@
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
#include <linux/of_irq.h>
#include <linux/hugetlb.h>
#include <linux/pgtable.h>
@@ -890,6 +891,8 @@ void __init setup_arch(char **cmdline_p)
/* Unflatten the device-tree passed by prom_init or kexec */
unflatten_device_tree();

+ fdt_init_reserved_mem();
+
/*
* Initialize cache line/block info from device-tree (on ppc64) or
* just cputable (on ppc32).
--
2.17.1