From 40f7bfe4f1c2761abeceb3b2b9dc1feec3c47ed9 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 19 May 2011 13:22:48 +0100 Subject: [PATCH] ARM: 6914/1: sparsemem: fix highmem detection when using SPARSEMEM sanity_check_meminfo walks over the registered memory banks and attempts to split banks across lowmem and highmem when they would otherwise overlap with the vmalloc space. When SPARSEMEM is used, there are two potential problems that occur when the virtual address of the start of a bank is equal to vmalloc_min. 1.) The end of lowmem is calculated as __pa(vmalloc_min - 1) + 1. In the above scenario, this will give the end address of the previous bank, rather than the actual bank we are interested in. This value is later used as the memblock limit and artificially restricts the total amount of available memory. 2.) The checks to determine whether or not a bank belongs to highmem or not only check if __va(bank->start) is greater or less than vmalloc_min. In the case that it is equal, the bank is incorrectly treated as lowmem, which hoses the vmalloc area. This patch fixes these two problems by checking whether the virtual start address of a bank is >= vmalloc_min and then calculating lowmem_end by finding the virtual end address of the highest lowmem bank. Acked-by: Catalin Marinas Reviewed-by: Nicolas Pitre Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/mm/mmu.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 08a9236..9d9e736 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -763,15 +763,12 @@ static void __init sanity_check_meminfo(void) { int i, j, highmem = 0; - lowmem_limit = __pa(vmalloc_min - 1) + 1; - memblock_set_current_limit(lowmem_limit); - for (i = 0, j = 0; i < meminfo.nr_banks; i++) { struct membank *bank = &meminfo.bank[j]; *bank = meminfo.bank[i]; #ifdef CONFIG_HIGHMEM - if (__va(bank->start) > vmalloc_min || + if (__va(bank->start) >= vmalloc_min || __va(bank->start) < (void *)PAGE_OFFSET) highmem = 1; @@ -829,6 +826,9 @@ static void __init sanity_check_meminfo(void) bank->size = newsize; } #endif + if (!bank->highmem && bank->start + bank->size > lowmem_limit) + lowmem_limit = bank->start + bank->size; + j++; } #ifdef CONFIG_HIGHMEM @@ -852,6 +852,7 @@ static void __init sanity_check_meminfo(void) } #endif meminfo.nr_banks = j; + memblock_set_current_limit(lowmem_limit); } static inline void prepare_page_table(void) -- 2.7.4