Commit 51930df5 authored by Mike Rapoport's avatar Mike Rapoport Committed by Linus Torvalds
Browse files

mm: free_area_init: allow defining max_zone_pfn in descending order 

Some architectures (e.g.  ARC) have the ZONE_HIGHMEM zone below the
ZONE_NORMAL.  Allowing free_area_init() parse max_zone_pfn array even it
is sorted in descending order allows using free_area_init() on such
architectures.

Add top -> down traversal of max_zone_pfn array in free_area_init() and
use the latter in ARC node/zone initialization.

[rppt@kernel.org: ARC fix]
  Link: http://lkml.kernel.org/r/20200504153901.GM14260@kernel.org
[rppt@linux.ibm.com: arc: free_area_init(): take into account PAE40 mode]
  Link: http://lkml.kernel.org/r/20200507205900.GH683243@linux.ibm.com


[akpm@linux-foundation.org: declare arch_has_descending_max_zone_pfns()]
Signed-off-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com>	[arm64]
Reviewed-by: default avatarBaoquan 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>
Cc: Guenter Roeck <linux@roeck-us.net>
Link: http://lkml.kernel.org/r/20200412194859.12663-18-rppt@kernel.org


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent acd3f5c4

arch/arc/mm/init.c

+12 −29
Original line number Diff line number Diff line
@@ -63,11 +63,13 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size) 


		low_mem_sz = size;

		in_use = 1;

		memblock_add_node(base, size, 0);

	} else {

#ifdef CONFIG_HIGHMEM

		high_mem_start = base;

		high_mem_sz = size;

		in_use = 1;

		memblock_add_node(base, size, 1);

#endif

	}
@@ -75,6 +77,11 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size) 
		base, TO_MB(size), !in_use ? "Not used":"");

}



bool arch_has_descending_max_zone_pfns(void)

{

	return !IS_ENABLED(CONFIG_ARC_HAS_PAE40);

}



/*

 * First memory setup routine called from setup_arch()

 * 1. setup swapper's mm @init_mm
@@ -83,8 +90,7 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size) 
 */

void __init setup_arch_memory(void)

{

	unsigned long zones_size[MAX_NR_ZONES];

	unsigned long zones_holes[MAX_NR_ZONES];

	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };



	init_mm.start_code = (unsigned long)_text;

	init_mm.end_code = (unsigned long)_etext;
@@ -115,7 +121,6 @@ void __init setup_arch_memory(void) 
	 * the crash

	 */



	memblock_add_node(low_mem_start, low_mem_sz, 0);

	memblock_reserve(CONFIG_LINUX_LINK_BASE,

			 __pa(_end) - CONFIG_LINUX_LINK_BASE);
@@ -133,22 +138,7 @@ void __init setup_arch_memory(void) 
	memblock_dump_all();



	/*----------------- node/zones setup --------------------------*/

	memset(zones_size, 0, sizeof(zones_size));

	memset(zones_holes, 0, sizeof(zones_holes));



	zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;

	zones_holes[ZONE_NORMAL] = 0;



	/*

	 * We can't use the helper free_area_init(zones[]) because it uses

	 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong

	 * when our kernel doesn't start at PAGE_OFFSET, i.e.

	 * PAGE_OFFSET != CONFIG_LINUX_RAM_BASE

	 */

	free_area_init_node(0,			/* node-id */

			    zones_size,		/* num pages per zone */

			    min_low_pfn,	/* first pfn of node */

			    zones_holes);	/* holes */

	max_zone_pfn[ZONE_NORMAL] = max_low_pfn;



#ifdef CONFIG_HIGHMEM

	/*
@@ -168,20 +158,13 @@ void __init setup_arch_memory(void) 
	min_high_pfn = PFN_DOWN(high_mem_start);

	max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);



	zones_size[ZONE_NORMAL] = 0;

	zones_holes[ZONE_NORMAL] = 0;



	zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn;

	zones_holes[ZONE_HIGHMEM] = 0;



	free_area_init_node(1,			/* node-id */

			    zones_size,		/* num pages per zone */

			    min_high_pfn,	/* first pfn of node */

			    zones_holes);	/* holes */

	max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn;



	high_memory = (void *)(min_high_pfn << PAGE_SHIFT);

	kmap_init();

#endif



	free_area_init(max_zone_pfn);

}



/*

include/linux/mm.h

+1 −0
Original line number Diff line number Diff line
@@ -2473,6 +2473,7 @@ extern void setup_per_cpu_pageset(void); 
extern int min_free_kbytes;

extern int watermark_boost_factor;

extern int watermark_scale_factor;

extern bool arch_has_descending_max_zone_pfns(void);



/* nommu.c */

extern atomic_long_t mmap_pages_allocated;

mm/page_alloc.c

+21 −5
Original line number Diff line number Diff line
@@ -7408,6 +7408,15 @@ static void check_for_memory(pg_data_t *pgdat, int nid) 
	}

}



/*

 * Some architecturs, e.g. ARC may have ZONE_HIGHMEM below ZONE_NORMAL. For

 * such cases we allow max_zone_pfn sorted in the descending order

 */

bool __weak arch_has_descending_max_zone_pfns(void)

{

	return false;

}



/**

 * free_area_init - Initialise all pg_data_t and zone data

 * @max_zone_pfn: an array of max PFNs for each zone
@@ -7424,7 +7433,8 @@ static void check_for_memory(pg_data_t *pgdat, int nid) 
void __init free_area_init(unsigned long *max_zone_pfn)

{

	unsigned long start_pfn, end_pfn;

	int i, nid;

	int i, nid, zone;

	bool descending;



	/* Record where the zone boundaries are */

	memset(arch_zone_lowest_possible_pfn, 0,
@@ -7433,14 +7443,20 @@ void __init free_area_init(unsigned long *max_zone_pfn) 
				sizeof(arch_zone_highest_possible_pfn));



	start_pfn = find_min_pfn_with_active_regions();

	descending = arch_has_descending_max_zone_pfns();



	for (i = 0; i < MAX_NR_ZONES; i++) {

		if (i == ZONE_MOVABLE)

		if (descending)

			zone = MAX_NR_ZONES - i - 1;

		else

			zone = i;



		if (zone == ZONE_MOVABLE)

			continue;



		end_pfn = max(max_zone_pfn[i], start_pfn);

		arch_zone_lowest_possible_pfn[i] = start_pfn;

		arch_zone_highest_possible_pfn[i] = end_pfn;

		end_pfn = max(max_zone_pfn[zone], start_pfn);

		arch_zone_lowest_possible_pfn[zone] = start_pfn;

		arch_zone_highest_possible_pfn[zone] = end_pfn;



		start_pfn = end_pfn;

	}

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