ia64: discontig: paging_init(): remove local max_pfn calculation

The maximal PFN in the system is calculated during find_memory() time and
it is stored at max_low_pfn then.

Use this value in paging_init() and remove the redundant detection of
max_pfn in that function.

Link: https://lkml.kernel.org/r/20201101170454.9567-5-rppt@kernel.orgSigned-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/ia64/mm/discontig.c

@@ -594,7 +594,6 @@ void __init paging_init(void)
 {
 	unsigned long max_dma;
 	unsigned long pfn_offset = 0;
-	unsigned long max_pfn = 0;
 	int node;
 	unsigned long max_zone_pfns[MAX_NR_ZONES];
 
@@ -616,13 +615,11 @@ void __init paging_init(void)
 #ifdef CONFIG_VIRTUAL_MEM_MAP
 		NODE_DATA(node)->node_mem_map = vmem_map + pfn_offset;
 #endif
-		if (mem_data[node].max_pfn > max_pfn)
-			max_pfn = mem_data[node].max_pfn;
 	}
 
 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 	max_zone_pfns[ZONE_DMA32] = max_dma;
-	max_zone_pfns[ZONE_NORMAL] = max_pfn;
+	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 	free_area_init(max_zone_pfns);
 
 	zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page));