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Commit 77f73a2c authored by Will Deacon's avatar Will Deacon Committed by Catalin Marinas
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ARM: LPAE: mark memory banks with start > ULONG_MAX as highmem 



Memory banks living outside of the 32-bit physical address
space do not have a 1:1 pa <-> va mapping and therefore the
__va macro may wrap.

This patch ensures that such banks are marked as highmem so
that the Kernel doesn't try to split them up when it sees that
the wrapped virtual address overlaps the vmalloc space.

Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarNicolas Pitre <nico@linaro.org>
parent ae2de101

arch/arm/mm/mmu.c

+15 −1
Original line number Diff line number Diff line
@@ -799,6 +799,9 @@ void __init sanity_check_meminfo(void) 
		struct membank *bank = &meminfo.bank[j];

		*bank = meminfo.bank[i];



		if (bank->start > ULONG_MAX)

			highmem = 1;



#ifdef CONFIG_HIGHMEM

		if (__va(bank->start) >= vmalloc_min ||

		    __va(bank->start) < (void *)PAGE_OFFSET)
@@ -810,7 +813,7 @@ void __init sanity_check_meminfo(void) 
		 * Split those memory banks which are partially overlapping

		 * the vmalloc area greatly simplifying things later.

		 */

		if (__va(bank->start) < vmalloc_min &&

		if (!highmem && __va(bank->start) < vmalloc_min &&

		    bank->size > vmalloc_min - __va(bank->start)) {

			if (meminfo.nr_banks >= NR_BANKS) {

				printk(KERN_CRIT "NR_BANKS too low, "
@@ -830,6 +833,17 @@ void __init sanity_check_meminfo(void) 
#else

		bank->highmem = highmem;



		/*

		 * Highmem banks not allowed with !CONFIG_HIGHMEM.

		 */

		if (highmem) {

			printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "

			       "(!CONFIG_HIGHMEM).\n",

			       (unsigned long long)bank->start,

			       (unsigned long long)bank->start + bank->size - 1);

			continue;

		}



		/*

		 * Check whether this memory bank would entirely overlap

		 * the vmalloc area.