Commit 4f5b0c17 authored by Mike Rapoport's avatar Mike Rapoport Committed by Linus Torvalds
Browse files

arm, arm64: move free_unused_memmap() to generic mm 

ARM and ARM64 free unused parts of the memory map just before the
initialization of the page allocator. To allow holes in the memory map both
architectures overload pfn_valid() and define HAVE_ARCH_PFN_VALID.

Allowing holes in the memory map for FLATMEM may be useful for small
machines, such as ARC and m68k and will enable those architectures to cease
using DISCONTIGMEM and still support more than one memory bank.

Move the functions that free unused memory map to generic mm and enable
them in case HAVE_ARCH_PFN_VALID=y.

Link: https://lkml.kernel.org/r/20201101170454.9567-10-rppt@kernel.org


Signed-off-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Alexey Dobriyan <adobriyan@gmail.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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5e545df3

arch/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -1044,6 +1044,9 @@ config ARCH_WANT_LD_ORPHAN_WARN 
	  by the linker, since the locations of such sections can change between linker

	  versions.



config HAVE_ARCH_PFN_VALID

	bool



source "kernel/gcov/Kconfig"



source "scripts/gcc-plugins/Kconfig"

arch/arm/Kconfig

+1 −3
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ config ARM 
	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU

	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU

	select HAVE_ARCH_MMAP_RND_BITS if MMU

	select HAVE_ARCH_PFN_VALID

	select HAVE_ARCH_SECCOMP

	select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT

	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
@@ -1489,9 +1490,6 @@ config ARCH_SPARSEMEM_ENABLE 
	bool

	select SPARSEMEM_STATIC if SPARSEMEM



config HAVE_ARCH_PFN_VALID

	def_bool y



config HIGHMEM

	bool "High Memory Support"

	depends on MMU

arch/arm/mm/init.c

+0 −78
Original line number Diff line number Diff line
@@ -267,83 +267,6 @@ static inline void poison_init_mem(void *s, size_t count) 
		*p++ = 0xe7fddef0;

}



static inline void __init

free_memmap(unsigned long start_pfn, unsigned long end_pfn)

{

	struct page *start_pg, *end_pg;

	phys_addr_t pg, pgend;



	/*

	 * Convert start_pfn/end_pfn to a struct page pointer.

	 */

	start_pg = pfn_to_page(start_pfn - 1) + 1;

	end_pg = pfn_to_page(end_pfn - 1) + 1;



	/*

	 * Convert to physical addresses, and

	 * round start upwards and end downwards.

	 */

	pg = PAGE_ALIGN(__pa(start_pg));

	pgend = __pa(end_pg) & PAGE_MASK;



	/*

	 * If there are free pages between these,

	 * free the section of the memmap array.

	 */

	if (pg < pgend)

		memblock_free_early(pg, pgend - pg);

}



/*

 * The mem_map array can get very big.  Free the unused area of the memory map.

 */

static void __init free_unused_memmap(void)

{

	unsigned long start, end, prev_end = 0;

	int i;



	/*

	 * This relies on each bank being in address order.

	 * The banks are sorted previously in bootmem_init().

	 */

	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {

#ifdef CONFIG_SPARSEMEM

		/*

		 * Take care not to free memmap entries that don't exist

		 * due to SPARSEMEM sections which aren't present.

		 */

		start = min(start,

				 ALIGN(prev_end, PAGES_PER_SECTION));

#else

		/*

		 * Align down here since the VM subsystem insists that the

		 * memmap entries are valid from the bank start aligned to

		 * MAX_ORDER_NR_PAGES.

		 */

		start = round_down(start, MAX_ORDER_NR_PAGES);

#endif

		/*

		 * If we had a previous bank, and there is a space

		 * between the current bank and the previous, free it.

		 */

		if (prev_end && prev_end < start)

			free_memmap(prev_end, start);



		/*

		 * Align up here since the VM subsystem insists that the

		 * memmap entries are valid from the bank end aligned to

		 * MAX_ORDER_NR_PAGES.

		 */

		prev_end = ALIGN(end, MAX_ORDER_NR_PAGES);

	}



#ifdef CONFIG_SPARSEMEM

	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))

		free_memmap(prev_end,

			    ALIGN(prev_end, PAGES_PER_SECTION));

#endif

}



static void __init free_highpages(void)

{

#ifdef CONFIG_HIGHMEM
@@ -385,7 +308,6 @@ void __init mem_init(void) 
	set_max_mapnr(pfn_to_page(max_pfn) - mem_map);



	/* this will put all unused low memory onto the freelists */

	free_unused_memmap();

	memblock_free_all();



#ifdef CONFIG_SA1111

arch/arm64/Kconfig

+1 −3
Original line number Diff line number Diff line
@@ -140,6 +140,7 @@ config ARM64 
	select HAVE_ARCH_KGDB

	select HAVE_ARCH_MMAP_RND_BITS

	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT

	select HAVE_ARCH_PFN_VALID

	select HAVE_ARCH_PREL32_RELOCATIONS

	select HAVE_ARCH_SECCOMP_FILTER

	select HAVE_ARCH_STACKLEAK
@@ -1043,9 +1044,6 @@ config ARCH_SELECT_MEMORY_MODEL 
config ARCH_FLATMEM_ENABLE

	def_bool !NUMA



config HAVE_ARCH_PFN_VALID

	def_bool y



config HW_PERF_EVENTS

	def_bool y

	depends on ARM_PMU

arch/arm64/mm/init.c

+0 −68
Original line number Diff line number Diff line
@@ -430,71 +430,6 @@ void __init bootmem_init(void) 
	memblock_dump_all();

}



#ifndef CONFIG_SPARSEMEM_VMEMMAP

static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)

{

	struct page *start_pg, *end_pg;

	unsigned long pg, pgend;



	/*

	 * Convert start_pfn/end_pfn to a struct page pointer.

	 */

	start_pg = pfn_to_page(start_pfn - 1) + 1;

	end_pg = pfn_to_page(end_pfn - 1) + 1;



	/*

	 * Convert to physical addresses, and round start upwards and end

	 * downwards.

	 */

	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));

	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;



	/*

	 * If there are free pages between these, free the section of the

	 * memmap array.

	 */

	if (pg < pgend)

		memblock_free(pg, pgend - pg);

}



/*

 * The mem_map array can get very big. Free the unused area of the memory map.

 */

static void __init free_unused_memmap(void)

{

	unsigned long start, end, prev_end = 0;

	int i;



	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {

#ifdef CONFIG_SPARSEMEM

		/*

		 * Take care not to free memmap entries that don't exist due

		 * to SPARSEMEM sections which aren't present.

		 */

		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));

#endif

		/*

		 * If we had a previous bank, and there is a space between the

		 * current bank and the previous, free it.

		 */

		if (prev_end && prev_end < start)

			free_memmap(prev_end, start);



		/*

		 * Align up here since the VM subsystem insists that the

		 * memmap entries are valid from the bank end aligned to

		 * MAX_ORDER_NR_PAGES.

		 */

		prev_end = ALIGN(end, MAX_ORDER_NR_PAGES);

	}



#ifdef CONFIG_SPARSEMEM

	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))

		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));

#endif

}

#endif	/* !CONFIG_SPARSEMEM_VMEMMAP */



/*

 * mem_init() marks the free areas in the mem_map and tells us how much memory

 * is free.  This is done after various parts of the system have claimed their
@@ -510,9 +445,6 @@ void __init mem_init(void) 


	set_max_mapnr(max_pfn - PHYS_PFN_OFFSET);



#ifndef CONFIG_SPARSEMEM_VMEMMAP

	free_unused_memmap();

#endif

	/* this will put all unused low memory onto the freelists */

	memblock_free_all();

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