12 files changed, 29 insertions, 39 deletions

diff --git a/arch/x86/include/asm/iommu.h b/arch/x86/include/asm/iommu.h
index 878b30715766..df42a712361f 100644
--- a/arch/x86/include/asm/iommu.h
+++ b/arch/x86/include/asm/iommu.h
@@ -2,7 +2,6 @@
 #define _ASM_X86_IOMMU_H
 
 static inline void iommu_shutdown_noop(void) {}
-extern void no_iommu_init(void);
 extern struct dma_map_ops nommu_dma_ops;
 extern int force_iommu, no_iommu;
 extern int iommu_detected;
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 0285521e0a99..66237fde758f 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -2110,8 +2110,8 @@ int __init amd_iommu_init_dma_ops(void)
                 prealloc_protection_domains();
 
         iommu_detected = 1;
-        force_iommu = 1;
         bad_dma_address = 0;
+        swiotlb = 0;
 #ifdef CONFIG_GART_IOMMU
         gart_iommu_aperture_disabled = 1;
         gart_iommu_aperture = 0;
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index c41aabddaa2a..0d4581e602a4 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -1330,7 +1330,7 @@ static int __init early_amd_iommu_detect(struct acpi_table_header *table)
 
 void __init amd_iommu_detect(void)
 {
-        if (swiotlb || no_iommu || (iommu_detected && !gart_iommu_aperture))
+        if (no_iommu || (iommu_detected && !gart_iommu_aperture))
                 return;
 
         if (acpi_table_parse("IVRS", early_amd_iommu_detect) == 0) {
diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 03933cf0b63c..e0dfb6856aa2 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -458,7 +458,7 @@ out:
 
         if (aper_alloc) {
                 /* Got the aperture from the AGP bridge */
-        } else if (swiotlb && !valid_agp) {
+        } else if (!valid_agp) {
                 /* Do nothing */
         } else if ((!no_iommu && max_pfn > MAX_DMA32_PFN) ||
                    force_iommu ||
diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index 47bd419ea4d2..833f491440b9 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -1360,7 +1360,7 @@ void __init detect_calgary(void)
          * if the user specified iommu=off or iommu=soft or we found
          * another HW IOMMU already, bail out.
          */
-        if (swiotlb || no_iommu || iommu_detected)
+        if (no_iommu || iommu_detected)
                 return;
 
         if (!use_calgary)
@@ -1445,10 +1445,6 @@ void __init detect_calgary(void)
                 printk(KERN_INFO "PCI-DMA: Calgary TCE table spec is %d\n",
                        specified_table_size);
 
-                /* swiotlb for devices that aren't behind the Calgary. */
-                if (max_pfn > MAX_DMA32_PFN)
-                        swiotlb = 1;
-
                 x86_init.iommu.iommu_init = calgary_iommu_init;
         }
         return;
@@ -1476,11 +1472,7 @@ int __init calgary_iommu_init(void)
                 return ret;
         }
 
-        force_iommu = 1;
         bad_dma_address = 0x0;
-        /* dma_ops is set to swiotlb or nommu */
-        if (!dma_ops)
-                dma_ops = &nommu_dma_ops;
 
         return 0;
 }
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index bed05e2e5890..a234e63c2656 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -124,24 +124,24 @@ static void __init dma32_free_bootmem(void)
 
 void __init pci_iommu_alloc(void)
 {
+        /* swiotlb is forced by the boot option */
+        int use_swiotlb = swiotlb;
 #ifdef CONFIG_X86_64
         /* free the range so iommu could get some range less than 4G */
         dma32_free_bootmem();
 #endif
+        pci_swiotlb_init();
+        if (use_swiotlb)
+                return;
 
-        /*
-         * The order of these functions is important for
-         * fall-back/fail-over reasons
-         */
         gart_iommu_hole_init();
 
         detect_calgary();
 
         detect_intel_iommu();
 
+        /* needs to be called after gart_iommu_hole_init */
         amd_iommu_detect();
-
-        pci_swiotlb_init();
 }
 
 void *dma_generic_alloc_coherent(struct device *dev, size_t size,
@@ -291,10 +291,15 @@ static int __init pci_iommu_init(void)
 #ifdef CONFIG_PCI
         dma_debug_add_bus(&pci_bus_type);
 #endif
-
         x86_init.iommu.iommu_init();
 
-        no_iommu_init();
+        if (swiotlb) {
+                printk(KERN_INFO "PCI-DMA: "
+                       "Using software bounce buffering for IO (SWIOTLB)\n");
+                swiotlb_print_info();
+        } else
+                swiotlb_free();
+
         return 0;
 }
 /* Must execute after PCI subsystem */
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 0410bd30060d..919182e15d1e 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -833,6 +833,7 @@ int __init gart_iommu_init(void)
         flush_gart();
         dma_ops = &gart_dma_ops;
         x86_platform.iommu_shutdown = gart_iommu_shutdown;
+        swiotlb = 0;
 
         return 0;
 }
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index a3933d4330cd..875e3822ae61 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -103,12 +103,3 @@ struct dma_map_ops nommu_dma_ops = {
         .sync_sg_for_device     = nommu_sync_sg_for_device,
         .is_phys                = 1,
 };
-
-void __init no_iommu_init(void)
-{
-        if (dma_ops)
-                return;
-
-        force_iommu = 0; /* no HW IOMMU */
-        dma_ops = &nommu_dma_ops;
-}
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index ea20ef7ca523..17ce4221bd03 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -46,13 +46,12 @@ 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))
+        if (!no_iommu && max_pfn > MAX_DMA32_PFN)
                 swiotlb = 1;
 #endif
-        if (swiotlb_force)
-                swiotlb = 1;
         if (swiotlb) {
                 swiotlb_init(0);
                 dma_ops = &swiotlb_dma_ops;
-        }
+        } else
+                dma_ops = &nommu_dma_ops;
 }
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index bce9cd7c755a..437399667e5a 100644
--- a/drivers/pci/dmar.c
+++ b/drivers/pci/dmar.c
@@ -613,8 +613,7 @@ void __init detect_intel_iommu(void)
                                "x2apic and Intr-remapping.\n");
 #endif
 #ifdef CONFIG_DMAR
-                if (ret && !no_iommu && !iommu_detected && !swiotlb &&
-                    !dmar_disabled)
+                if (ret && !no_iommu && !iommu_detected && !dmar_disabled)
                         iommu_detected = 1;
 #endif
 #ifdef CONFIG_X86
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index b1e97e682500..43d755a2e14a 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -3231,7 +3231,7 @@ int __init intel_iommu_init(void)
          * Check the need for DMA-remapping initialization now.
          * Above initialization will also be used by Interrupt-remapping.
          */
-        if (no_iommu || swiotlb || dmar_disabled)
+        if (no_iommu || dmar_disabled)
                 return -ENODEV;
 
         iommu_init_mempool();
@@ -3252,7 +3252,9 @@ int __init intel_iommu_init(void)
         "PCI-DMA: Intel(R) Virtualization Technology for Directed I/O\n");
 
         init_timer(&unmap_timer);
-        force_iommu = 1;
+#ifdef CONFIG_SWIOTLB
+        swiotlb = 0;
+#endif
         dma_ops = &intel_dma_ops;
 
         init_iommu_sysfs();
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 0c12d7cce300..e6755a0574fb 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -109,8 +109,10 @@ setup_io_tlb_npages(char *str)
         }
         if (*str == ',')
                 ++str;
-        if (!strcmp(str, "force"))
+        if (!strcmp(str, "force")) {
                 swiotlb_force = 1;
+                swiotlb = 1;
+        }
         return 1;
 }
 __setup("swiotlb=", setup_io_tlb_npages);