arm64: simplify detection of memory zone boundaries for UMA configs

The free_area_init() function only requires the definition of maximal PFN
for each of the supported zone rater than calculation of actual zone sizes
and the sizes of the holes between the zones.

After removal of CONFIG_HAVE_MEMBLOCK_NODE_MAP the free_area_init() is
available to all architectures.

Using this function instead of free_area_init_node() simplifies the zone
detection.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com>	[arm64]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-9-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/arm64/mm/init.c

@@ -192,8 +192,6 @@ static phys_addr_t __init max_zone_phys(unsigned int zone_bits)
 	return min(offset + (1ULL << zone_bits), memblock_end_of_DRAM());
 }
 
-#ifdef CONFIG_NUMA
-
 static void __init zone_sizes_init(unsigned long min, unsigned long max)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES]  = {0};
@@ -209,58 +207,6 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
 	free_area_init(max_zone_pfns);
 }
 
-#else
-
-static void __init zone_sizes_init(unsigned long min, unsigned long max)
-{
-	struct memblock_region *reg;
-	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
-	unsigned long __maybe_unused max_dma, max_dma32;
-
-	memset(zone_size, 0, sizeof(zone_size));
-
-	max_dma = max_dma32 = min;
-#ifdef CONFIG_ZONE_DMA
-	max_dma = max_dma32 = PFN_DOWN(arm64_dma_phys_limit);
-	zone_size[ZONE_DMA] = max_dma - min;
-#endif
-#ifdef CONFIG_ZONE_DMA32
-	max_dma32 = PFN_DOWN(arm64_dma32_phys_limit);
-	zone_size[ZONE_DMA32] = max_dma32 - max_dma;
-#endif
-	zone_size[ZONE_NORMAL] = max - max_dma32;
-
-	memcpy(zhole_size, zone_size, sizeof(zhole_size));
-
-	for_each_memblock(memory, reg) {
-		unsigned long start = memblock_region_memory_base_pfn(reg);
-		unsigned long end = memblock_region_memory_end_pfn(reg);
-
-#ifdef CONFIG_ZONE_DMA
-		if (start >= min && start < max_dma) {
-			unsigned long dma_end = min(end, max_dma);
-			zhole_size[ZONE_DMA] -= dma_end - start;
-			start = dma_end;
-		}
-#endif
-#ifdef CONFIG_ZONE_DMA32
-		if (start >= max_dma && start < max_dma32) {
-			unsigned long dma32_end = min(end, max_dma32);
-			zhole_size[ZONE_DMA32] -= dma32_end - start;
-			start = dma32_end;
-		}
-#endif
-		if (start >= max_dma32 && start < max) {
-			unsigned long normal_end = min(end, max);
-			zhole_size[ZONE_NORMAL] -= normal_end - start;
-		}
-	}
-
-	free_area_init_node(0, zone_size, min, zhole_size);
-}
-
-#endif /* CONFIG_NUMA */
-
 int pfn_valid(unsigned long pfn)
 {
 	phys_addr_t addr = pfn << PAGE_SHIFT;