x86: unify pci iommu setup and allow swiotlb to compile for 32 bit

swiotlb on 32 bit will be used by Xen domain 0 support.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 8 insertions, 3 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index b62a7667828e..a9c656f2d661 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -105,6 +105,8 @@ microcode-$(CONFIG_MICROCODE_INTEL)	+= microcode_intel.o
 microcode-$(CONFIG_MICROCODE_AMD)       += microcode_amd.o
 obj-$(CONFIG_MICROCODE)                 += microcode.o
 
+obj-$(CONFIG_SWIOTLB)                   += pci-swiotlb_64.o # NB rename without _64
+
 ###
 # 64 bit specific files
 ifeq ($(CONFIG_X86_64),y)
@@ -118,7 +120,6 @@ ifeq ($(CONFIG_X86_64),y)
         obj-$(CONFIG_GART_IOMMU)        += pci-gart_64.o aperture_64.o
         obj-$(CONFIG_CALGARY_IOMMU)     += pci-calgary_64.o tce_64.o
         obj-$(CONFIG_AMD_IOMMU)         += amd_iommu_init.o amd_iommu.o
-        obj-$(CONFIG_SWIOTLB)           += pci-swiotlb_64.o
 
         obj-$(CONFIG_PCI_MMCONFIG)      += mmconf-fam10h_64.o
 endif
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index e150ad4f0ccc..00e07447a5bd 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -105,11 +105,15 @@ static void __init dma32_free_bootmem(void)
         dma32_bootmem_ptr = NULL;
         dma32_bootmem_size = 0;
 }
+#endif
 
 void __init pci_iommu_alloc(void)
 {
+#ifdef CONFIG_X86_64
         /* free the range so iommu could get some range less than 4G */
         dma32_free_bootmem();
+#endif
+
         /*
          * The order of these functions is important for
          * fall-back/fail-over reasons
@@ -125,8 +129,6 @@ void __init pci_iommu_alloc(void)
         pci_swiotlb_init();
 }
 
-#endif
-
 void *dma_generic_alloc_coherent(struct device *dev, size_t size,
                                  dma_addr_t *dma_addr, gfp_t flag)
 {
diff --git a/arch/x86/kernel/pci-swiotlb_64.c b/arch/x86/kernel/pci-swiotlb_64.c
index f47a097a135b..a991afea6700 100644
--- a/arch/x86/kernel/pci-swiotlb_64.c
+++ b/arch/x86/kernel/pci-swiotlb_64.c
@@ -62,8 +62,10 @@ struct dma_mapping_ops swiotlb_dma_ops = {
 void __init pci_swiotlb_init(void)
 {
         /* don't initialize swiotlb if iommu=off (no_iommu=1) */
+#ifdef CONFIG_X86_64
         if (!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN)
                swiotlb = 1;
+#endif
         if (swiotlb_force)
                 swiotlb = 1;
         if (swiotlb) {