[PATCH] x86_64: Fix off by one in IOMMU check

Fix off by one when checking if the machine has enougn memory to need IOMMU
This caused the IOMMUs to be needlessly enabled for mem=4G

Based on a patch from Jon Mason

Signed-off-by: jdmason@us.ibm.com
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/x86_64/kernel/aperture.c b/arch/x86_64/kernel/aperture.c
index c7f4fdd20f05ff78ee731054170de372f9c0cf40..e4e2b7d01f8914c67cba5ad3bf5201db76b9ef96 100644 (file)
--- a/arch/x86_64/kernel/aperture.c
+++ b/arch/x86_64/kernel/aperture.c
@@ -23,6 +23,7 @@
 #include <asm/io.h>
 #include <asm/proto.h>
 #include <asm/pci-direct.h>
+#include <asm/dma.h>
 
 int iommu_aperture;
 int iommu_aperture_disabled __initdata = 0;
@@ -247,7 +248,7 @@ void __init iommu_hole_init(void)
                /* Got the aperture from the AGP bridge */
        } else if (swiotlb && !valid_agp) {
                /* Do nothing */
-       } else if ((!no_iommu && end_pfn >= 0xffffffff>>PAGE_SHIFT) ||
+       } else if ((!no_iommu && end_pfn >= MAX_DMA32_PFN) ||
                   force_iommu ||
                   valid_agp ||
                   fallback_aper_force) { 

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index bdc589924b104d2eaaa170e16340632a918bb00e..83ea86e0633a975d3033041785a598064932d4fd 100644 (file)
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -37,6 +37,7 @@
 #include <asm/proto.h>
 #include <asm/mach_apic.h>
 #include <asm/acpi.h>
+#include <asm/dma.h>
 
 #define __apicdebuginit  __init
 
@@ -281,7 +282,7 @@ void __init check_ioapic(void)
                                switch (vendor) { 
                                case PCI_VENDOR_ID_VIA:
 #ifdef CONFIG_GART_IOMMU
-                                       if ((end_pfn >= (0xffffffff>>PAGE_SHIFT) ||
+                                       if ((end_pfn > MAX_DMA32_PFN ||
                                             force_iommu) &&
                                            !iommu_aperture_allowed) {
                                                printk(KERN_INFO

diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c
index 2b865c90b0414b2a33f652333fa34881cc817de5..116e00f1bb7b5267643e1486b8c825c8f4eedf03 100644 (file)
--- a/arch/x86_64/kernel/pci-gart.c
+++ b/arch/x86_64/kernel/pci-gart.c
@@ -804,7 +804,7 @@ static int __init pci_iommu_init(void)
        } 
        
        if (no_iommu ||
-           (!force_iommu && end_pfn < 0xffffffff>>PAGE_SHIFT) ||
+           (!force_iommu && (end_pfn-1) < 0xffffffff>>PAGE_SHIFT) ||
            !iommu_aperture ||
            (no_agp && init_k8_gatt(&info) < 0)) {
                printk(KERN_INFO "PCI-DMA: Disabling IOMMU.\n"); 

diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 1faae5fc1c01c35c5e7cd7b1458bc34b5f63dd05..5337ca0ea7b9733b0ac91c6a323362079ba88f4b 100644 (file)
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -424,7 +424,7 @@ void __init mem_init(void)
 
 #ifdef CONFIG_SWIOTLB
        if (!iommu_aperture &&
-           (end_pfn >= 0xffffffff>>PAGE_SHIFT || force_iommu))
+           ((end_pfn-1) >= 0xffffffff>>PAGE_SHIFT || force_iommu))
               swiotlb = 1;
        if (swiotlb)
                swiotlb_init();