[RFC 11/23] ARM: mm: cleanup checks for membank overlap with vmalloc area

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


On Keystone platforms, physical memory is entirely outside the 32-bit
addressible range. Therefore, the (bank->start > ULONG_MAX) check below marks
the entire system memory as highmem, and this causes unpleasentness all over.

This patch eliminates the extra bank start check (against ULONG_MAX) by
checking bank->start against the physical address corresponding to vmalloc_min
instead.

In the process, this patch also cleans up parts of the highmem sanity check
code by removing what has now become a redundant check for banks that entirely
overlap with the vmalloc range.

Signed-off-by: Cyril Chemparathy <cyril@xxxxxx>
Signed-off-by: Vitaly Andrianov <vitalya@xxxxxx>
---
arch/arm/mm/mmu.c | 19 +------------------
1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index adaf8c3..4840efa 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -907,15 +907,12 @@ 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 (bank->start >= vmalloc_limit)
highmem = 1;

bank->highmem = highmem;

+#ifdef CONFIG_HIGHMEM
/*
* Split those memory banks which are partially overlapping
* the vmalloc area greatly simplifying things later.
@@ -938,8 +935,6 @@ void __init sanity_check_meminfo(void)
bank->size = vmalloc_limit - bank->start;
}
#else
- bank->highmem = highmem;
-
/*
* Highmem banks not allowed with !CONFIG_HIGHMEM.
*/
@@ -952,18 +947,6 @@ void __init sanity_check_meminfo(void)
}

/*
- * Check whether this memory bank would entirely overlap
- * the vmalloc area.
- */
- if (bank->start >= vmalloc_limit) {
- printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "
- "(vmalloc region overlap).\n",
- (unsigned long long)bank->start,
- (unsigned long long)bank->start + bank->size - 1);
- continue;
- }
-
- /*
* Check whether this memory bank would partially overlap
* the vmalloc area.
*/
--
1.7.9.5

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