[RFC 12/23] ARM: mm: clean up membank size limit checks

From: Cyril Chemparathy
Date: Mon Jul 23 2012 - 21:13:14 EST


This patch cleans up the highmem sanity check code by simplifying the range
checks with a pre-calculated size_limit. This patch should otherwise have no
functional impact on behavior.

This patch also removes a redundant (bank->start < vmalloc_limit) check, since
this is already covered by the !highmem condition.

Signed-off-by: Cyril Chemparathy <cyril@xxxxxx>
Signed-off-by: Vitaly Andrianov <vitalya@xxxxxx>
---
arch/arm/mm/mmu.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 4840efa..6b0baf3 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -905,10 +905,15 @@ void __init sanity_check_meminfo(void)

for (i = 0, j = 0; i < meminfo.nr_banks; i++) {
struct membank *bank = &meminfo.bank[j];
+ phys_addr_t size_limit;
+
*bank = meminfo.bank[i];
+ size_limit = bank->size;

if (bank->start >= vmalloc_limit)
highmem = 1;
+ else
+ size_limit = vmalloc_limit - bank->start;

bank->highmem = highmem;

@@ -917,8 +922,7 @@ void __init sanity_check_meminfo(void)
* Split those memory banks which are partially overlapping
* the vmalloc area greatly simplifying things later.
*/
- if (!highmem && bank->start < vmalloc_limit &&
- bank->size > vmalloc_limit - bank->start) {
+ if (!highmem && bank->size > size_limit) {
if (meminfo.nr_banks >= NR_BANKS) {
printk(KERN_CRIT "NR_BANKS too low, "
"ignoring high memory\n");
@@ -927,12 +931,12 @@ void __init sanity_check_meminfo(void)
(meminfo.nr_banks - i) * sizeof(*bank));
meminfo.nr_banks++;
i++;
- bank[1].size -= vmalloc_limit - bank->start;
+ bank[1].size -= size_limit;
bank[1].start = vmalloc_limit;
bank[1].highmem = highmem = 1;
j++;
}
- bank->size = vmalloc_limit - bank->start;
+ bank->size = size_limit;
}
#else
/*
@@ -950,14 +954,13 @@ void __init sanity_check_meminfo(void)
* Check whether this memory bank would partially overlap
* the vmalloc area.
*/
- if (bank->start + bank->size > vmalloc_limit)
- unsigned long newsize = vmalloc_limit - bank->start;
+ if (bank->size > size_limit) {
printk(KERN_NOTICE "Truncating RAM at %.8llx-%.8llx "
"to -%.8llx (vmalloc region overlap).\n",
(unsigned long long)bank->start,
(unsigned long long)bank->start + bank->size - 1,
- (unsigned long long)bank->start + newsize - 1);
- bank->size = newsize;
+ (unsigned long long)bank->start + size_limit - 1);
+ bank->size = size_limit;
}
#endif
if (!bank->highmem && bank->start + bank->size > arm_lowmem_limit)
--
1.7.9.5

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