path: root/arch/arm
diff options
authorWill Deacon <will.deacon@arm.com>2011-05-19 13:22:48 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-05-26 10:23:25 +0100
commit40f7bfe4f1c2761abeceb3b2b9dc1feec3c47ed9 (patch)
treef7ed5abed753ec18fd5874d1088afc02dc23de0c /arch/arm
parent7b7bf499f79de3f6c85a340c8453a78789523f85 (diff)
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 <catalin.marinas@arm.com> Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 08a92368d9d3..9d9e736c2b4f 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];
- 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;
+ if (!bank->highmem && bank->start + bank->size > lowmem_limit)
+ lowmem_limit = bank->start + bank->size;
@@ -852,6 +852,7 @@ static void __init sanity_check_meminfo(void)
meminfo.nr_banks = j;
+ memblock_set_current_limit(lowmem_limit);
static inline void prepare_page_table(void)