From: Yinghai Lu <yinghai@kernel.org>
Date: Sat, 17 Nov 2012 03:38:50 +0000 (-0800)
Subject: x86, mm: use pfn_range_is_mapped() with gart
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5101730cb0613b91d40b9bb7be6bb023d2f6aa24;p=linux-beck.git

x86, mm: use pfn_range_is_mapped() with gart

We are going to map ram only, so under max_low_pfn_mapped,
between 4g and max_pfn_mapped does not mean mapped at all.

Use pfn_range_is_mapped() directly.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-14-git-send-email-yinghai@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---

diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c
index e66311200cbd..b574b295a2f9 100644
--- a/arch/x86/kernel/amd_gart_64.c
+++ b/arch/x86/kernel/amd_gart_64.c
@@ -768,10 +768,9 @@ int __init gart_iommu_init(void)
 	aper_base	= info.aper_base;
 	end_pfn		= (aper_base>>PAGE_SHIFT) + (aper_size>>PAGE_SHIFT);
 
-	if (end_pfn > max_low_pfn_mapped) {
-		start_pfn = (aper_base>>PAGE_SHIFT);
+	start_pfn = PFN_DOWN(aper_base);
+	if (!pfn_range_is_mapped(start_pfn, end_pfn))
 		init_memory_mapping(start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT);
-	}
 
 	pr_info("PCI-DMA: using GART IOMMU.\n");
 	iommu_size = check_iommu_size(info.aper_base, aper_size);