From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Mon, 7 Nov 2011 16:16:56 +0000 Subject: [PATCH v8 14/16] ARM: LPAE: mark memory banks with start > ULONG_MAX as highmem In-Reply-To: <1320682618-1182-1-git-send-email-catalin.marinas@arm.com> References: <1320682618-1182-1-git-send-email-catalin.marinas@arm.com> Message-ID: <1320682618-1182-15-git-send-email-catalin.marinas@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Will Deacon 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: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm/mm/mmu.c | 16 +++++++++++++++- 1 files changed, 15 insertions(+), 1 deletions(-) diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 1935311..b836d6b 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -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, " @@ -831,6 +834,17 @@ void __init sanity_check_meminfo(void) 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. */