h8300, nds32, openrisc: simplify detection of memory extents

Instead of traversing memblock.memory regions to find memory_start and
memory_end, simply query memblock_{start,end}_of_DRAM().
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Emil Renner Berthing <kernel@esmil.dk>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20200818151634.14343-6-rppt@kernel.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/h8300/kernel/setup.c

@@ -74,17 +74,15 @@ static void __init bootmem_init(void)
 	memory_end = memory_start = 0;
 
 	/* Find main memory where is the kernel */
-	for_each_memblock(memory, region) {
-		memory_start = region->base;
-		memory_end = region->base + region->size;
-	}
+	memory_start = memblock_start_of_DRAM();
+	memory_end = memblock_end_of_DRAM();
 
 	if (!memory_end)
 		panic("No memory!");
 
 	/* setup bootmem globals (we use no_bootmem, but mm still depends on this) */
 	min_low_pfn = PFN_UP(memory_start);
-	max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
+	max_low_pfn = PFN_DOWN(memory_end);
 	max_pfn = max_low_pfn;
 
 	memblock_reserve(__pa(_stext), _end - _stext);

arch/nds32/kernel/setup.c

@@ -249,12 +249,8 @@ static void __init setup_memory(void)
 	memory_end = memory_start = 0;
 
 	/* Find main memory where is the kernel */
-	for_each_memblock(memory, region) {
-		memory_start = region->base;
-		memory_end = region->base + region->size;
-		pr_info("%s: Memory: 0x%x-0x%x\n", __func__,
-			memory_start, memory_end);
-	}
+	memory_start = memblock_start_of_DRAM();
+	memory_end = memblock_end_of_DRAM();
 
 	if (!memory_end) {
 		panic("No memory!");

arch/openrisc/kernel/setup.c

@@ -48,17 +48,12 @@ static void __init setup_memory(void)
 	unsigned long ram_start_pfn;
 	unsigned long ram_end_pfn;
 	phys_addr_t memory_start, memory_end;
-	struct memblock_region *region;
 
 	memory_end = memory_start = 0;
 
 	/* Find main memory where is the kernel, we assume its the only one */
-	for_each_memblock(memory, region) {
-		memory_start = region->base;
-		memory_end = region->base + region->size;
-		printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__,
-		       memory_start, memory_end);
-	}
+	memory_start = memblock_start_of_DRAM();
+	memory_end = memblock_end_of_DRAM();
 
 	if (!memory_end) {
 		panic("No memory!");