MIPS: Loongson3,SGI-IP27: Simplify max_low_pfn calculation

Both the Loongson3 & SGI-IP27 platforms set max_low_pfn to the last
available PFN describing memory. They both do it in paging_init() which
is later than ideal since max_low_pfn is used before that function is
called. Simplify both platforms to trivially initialize max_low_pfn
using the end address of DRAM, and do it earlier in prom_meminit().

Signed-off-by: Paul Burton <paul.burton@mips.com>
Suggested-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Patchwork: https://patchwork.linux-mips.org/patch/21104/
References: https://patchwork.linux-mips.org/patch/21031/
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Cc: linux-mips@linux-mips.org

2 files changed, 3 insertions, 20 deletions

diff --git a/arch/mips/loongson64/loongson-3/numa.c b/arch/mips/loongson64/loongson-3/numa.c
index 622761878cd1..60bf0a1cb757 100644
--- a/arch/mips/loongson64/loongson-3/numa.c
+++ b/arch/mips/loongson64/loongson-3/numa.c
@@ -231,6 +231,8 @@ static __init void prom_meminit(void)
                         cpumask_clear(&__node_data[(node)]->cpumask);
                 }
         }
+        max_low_pfn = PHYS_PFN(memblock_end_of_DRAM());
+
         for (cpu = 0; cpu < loongson_sysconf.nr_cpus; cpu++) {
                 node = cpu / loongson_sysconf.cores_per_node;
                 if (node >= num_online_nodes())
@@ -248,19 +250,9 @@ static __init void prom_meminit(void)
 
 void __init paging_init(void)
 {
-        unsigned node;
         unsigned long zones_size[MAX_NR_ZONES] = {0, };
 
         pagetable_init();
-
-        for_each_online_node(node) {
-                unsigned long  start_pfn, end_pfn;
-
-                get_pfn_range_for_nid(node, &start_pfn, &end_pfn);
-
-                if (end_pfn > max_low_pfn)
-                        max_low_pfn = end_pfn;
-        }
 #ifdef CONFIG_ZONE_DMA32
         zones_size[ZONE_DMA32] = MAX_DMA32_PFN;
 #endif
diff --git a/arch/mips/sgi-ip27/ip27-memory.c b/arch/mips/sgi-ip27/ip27-memory.c
index d8b8444d6795..813d13f92957 100644
--- a/arch/mips/sgi-ip27/ip27-memory.c
+++ b/arch/mips/sgi-ip27/ip27-memory.c
@@ -435,6 +435,7 @@ void __init prom_meminit(void)
 
         mlreset();
         szmem();
+        max_low_pfn = PHYS_PFN(memblock_end_of_DRAM());
 
         for (node = 0; node < MAX_COMPACT_NODES; node++) {
                 if (node_online(node)) {
@@ -455,18 +456,8 @@ extern void setup_zero_pages(void);
 void __init paging_init(void)
 {
         unsigned long zones_size[MAX_NR_ZONES] = {0, };
-        unsigned node;
 
         pagetable_init();
-
-        for_each_online_node(node) {
-                unsigned long start_pfn, end_pfn;
-
-                get_pfn_range_for_nid(node, &start_pfn, &end_pfn);
-
-                if (end_pfn > max_low_pfn)
-                        max_low_pfn = end_pfn;
-        }
         zones_size[ZONE_NORMAL] = max_low_pfn;
         free_area_init_nodes(zones_size);
 }