generic, x86: fix add iommu_num_pages helper function

This IOMMU helper function doesn't work for some architectures:

  http://marc.info/?l=linux-kernel&m=121699304403202&w=2

It also breaks POWER and SPARC builds:

  http://marc.info/?l=linux-kernel&m=121730388001890&w=2

Currently, only x86 IOMMUs use this so let's move it to x86 for
now.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 10 insertions, 9 deletions

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 8dbffb846de9..87d4d6964ec2 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -123,6 +123,14 @@ void __init pci_iommu_alloc(void)
 
         pci_swiotlb_init();
 }
+
+unsigned long iommu_num_pages(unsigned long addr, unsigned long len)
+{
+        unsigned long size = roundup((addr & ~PAGE_MASK) + len, PAGE_SIZE);
+
+        return size >> PAGE_SHIFT;
+}
+EXPORT_SYMBOL(iommu_num_pages);
 #endif
 
 /*
diff --git a/include/asm-x86/iommu.h b/include/asm-x86/iommu.h
index ecc8061904a9..5f888cc5be49 100644
--- a/include/asm-x86/iommu.h
+++ b/include/asm-x86/iommu.h
@@ -7,6 +7,8 @@ extern struct dma_mapping_ops nommu_dma_ops;
 extern int force_iommu, no_iommu;
 extern int iommu_detected;
 
+extern unsigned long iommu_num_pages(unsigned long addr, unsigned long len);
+
 #ifdef CONFIG_GART_IOMMU
 extern int gart_iommu_aperture;
 extern int gart_iommu_aperture_allowed;
diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h
index f8598f583944..c975caf75385 100644
--- a/include/linux/iommu-helper.h
+++ b/include/linux/iommu-helper.h
@@ -8,4 +8,3 @@ extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
                                       unsigned long align_mask);
 extern void iommu_area_free(unsigned long *map, unsigned long start,
                             unsigned int nr);
-extern unsigned long iommu_num_pages(unsigned long addr, unsigned long len);
diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c
index 889ddce2021e..a3b8d4c3f77a 100644
--- a/lib/iommu-helper.c
+++ b/lib/iommu-helper.c
@@ -80,11 +80,3 @@ void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr)
         }
 }
 EXPORT_SYMBOL(iommu_area_free);
-
-unsigned long iommu_num_pages(unsigned long addr, unsigned long len)
-{
-        unsigned long size = roundup((addr & ~PAGE_MASK) + len, PAGE_SIZE);
-
-        return size >> PAGE_SHIFT;
-}
-EXPORT_SYMBOL(iommu_num_pages);