Commit f171b55f authored by Mike Rapoport (Microsoft)'s avatar Mike Rapoport (Microsoft) Committed by Andrew Morton
Browse files

mips: fix HIGHMEM initialization 

Commit 6faea342 ("arch, mm: streamline HIGHMEM freeing") overzealously
removed mem_init_free_highmem() function that beside freeing high memory
pages checked for CPU support for high memory as a prerequisite.

Partially restore mem_init_free_highmem() with a new highmem_init() name
and make it discard high memory in case there is no CPU support for it.

Link: https://lkml.kernel.org/r/20251231105701.519711-1-rppt@kernel.org


Fixes: 6faea342 ("arch, mm: streamline HIGHMEM freeing")
Signed-off-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Reported-by: default avatarMarkus Stockhausen <markus.stockhausen@gmx.de>
Cc: Chris Packham <chris.packham@alliedtelesis.co.nz>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: Jonas Jelonek <jelonek.jonas@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent b0201916

arch/mips/mm/init.c

+23 −0
Original line number Diff line number Diff line
@@ -425,6 +425,28 @@ void __init paging_init(void) 
static struct kcore_list kcore_kseg0;

#endif



static inline void __init highmem_init(void)

{

#ifdef CONFIG_HIGHMEM

	unsigned long tmp;



	/*

	 * If CPU cannot support HIGHMEM discard the memory above highstart_pfn

	 */

	if (cpu_has_dc_aliases) {

		memblock_remove(PFN_PHYS(highstart_pfn), -1);

		return;

	}



	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {

		struct page *page = pfn_to_page(tmp);



		if (!memblock_is_memory(PFN_PHYS(tmp)))

			SetPageReserved(page);

	}

#endif

}



void __init arch_mm_preinit(void)

{

	/*
@@ -435,6 +457,7 @@ void __init arch_mm_preinit(void) 


	maar_init();

	setup_zero_pages();	/* Setup zeroed pages.  */

	highmem_init();



#ifdef CONFIG_64BIT

	if ((unsigned long) &_text > (unsigned long) CKSEG0)