[PATCH] ARM: ioremap: fix boundary check when reusing static mapping

[Pawel Moll]

Since commit 576d2f2525612ecb5af029a76f21f22a3b82563d "ARM: add
generic ioremap optimization by reusing static mappings" ioremap()
is trying to reuse existing, static mapping when possible.

The condition checking boundaries of the requested and existing
mappings didn't take in-page offset into consideration though,
which lead to obscure and hard to debug problems when.

Cc: Nicolas Pitre <nico at fluxnic.net>
Signed-off-by: Pawel Moll <pawel.moll at arm.com>
---
 arch/arm/mm/ioremap.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 80632e8..ba15937 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -225,7 +225,8 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
 		if ((area->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
 			continue;
 		if (__phys_to_pfn(area->phys_addr) > pfn ||
-		    __pfn_to_phys(pfn) + size-1 > area->phys_addr + area->size-1)
+		    __pfn_to_phys(pfn) + offset + size-1 >
+		    area->phys_addr + area->size-1)
 			continue;
 		/* we can drop the lock here as we know *area is static */
 		read_unlock(&vmlist_lock);
-- 
1.7.5.4