mm: free_area_init: use maximal zone PFNs rather than zone sizes

Currently, architectures that use free_area_init() to initialize memory
map and node and zone structures need to calculate zone and hole sizes.
We can use free_area_init_nodes() instead and let it detect the zone
boundaries while the architectures will only have to supply the possible
limits for the zones.

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]
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
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/20200412194859.12663-5-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 8 deletions

diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 30885d0b94ac..401b22f14743 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -158,8 +158,8 @@ static void __init fixaddr_user_init( void)
 
 void __init paging_init(void)
 {
-	unsigned long zones_size[MAX_NR_ZONES], vaddr;
-	int i;
+	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
+	unsigned long vaddr;
 
 	empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,
 							       PAGE_SIZE);
@@ -167,12 +167,8 @@ void __init paging_init(void)
 		panic("%s: Failed to allocate %lu bytes align=%lx\n",
 		      __func__, PAGE_SIZE, PAGE_SIZE);
 
-	for (i = 0; i < ARRAY_SIZE(zones_size); i++)
-		zones_size[i] = 0;
-
-	zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
-		(uml_physmem >> PAGE_SHIFT);
-	free_area_init(zones_size);
+	max_zone_pfn[ZONE_NORMAL] = end_iomem >> PAGE_SHIFT;
+	free_area_init(max_zone_pfn);
 
 	/*
 	 * Fixed mappings, only the page table structure has to be