[PATCH] x86_64: no_iommu removal in pci-gart.c

In previous versions of pci-gart.c, no_iommu was used to determine if IOMMU was
disabled in the GART DMA mapping functions.  This changed in 2.6.16 and now
gart_xxx() functions are only called if gart is enabled.  Therefore, uses of
no_iommu in the GART code are no longer necessary and can be removed.

Also, it removes double deceleration of no_iommu and force_iommu in pci.h and
proto.h, by removing the deceleration in pci.h.

Lastly, end_pfn off by one error.

Tested (along with patch 1/2) on dual opteron with gart enabled, iommu=soft,
and iommu=off.

Signed-off-by: Jon Mason <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 e4e2b7d..a0f955b 100644 (file)
--- a/arch/x86_64/kernel/aperture.c
+++ b/arch/x86_64/kernel/aperture.c
@@ -248,7 +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 >= MAX_DMA32_PFN) ||
+       } else if ((!no_iommu && end_pfn > MAX_DMA32_PFN) ||
                   force_iommu ||
                   valid_agp ||
                   fallback_aper_force) { 

diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c
index dd0718d..0c3f052 100644 (file)
--- a/arch/x86_64/kernel/pci-gart.c
+++ b/arch/x86_64/kernel/pci-gart.c
@@ -228,11 +228,6 @@ static inline int need_iommu(struct device *dev, unsigned long addr, size_t size
        int mmu = high;
        if (force_iommu) 
                mmu = 1; 
-       if (no_iommu) { 
-               if (high) 
-                       panic("PCI-DMA: high address but no IOMMU.\n"); 
-               mmu = 0; 
-       }       
        return mmu; 
 }
 
@@ -241,11 +236,6 @@ static inline int nonforced_iommu(struct device *dev, unsigned long addr, size_t
        u64 mask = *dev->dma_mask;
        int high = addr + size >= mask;
        int mmu = high;
-       if (no_iommu) { 
-               if (high) 
-                       panic("PCI-DMA: high address but no IOMMU.\n"); 
-               mmu = 0; 
-       }       
        return mmu; 
 }
 
@@ -310,7 +300,7 @@ void gart_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, int di
 
        for (i = 0; i < nents; i++) {
                struct scatterlist *s = &sg[i];
-               if (!s->dma_length)
+               if (!s->dma_length || !s->length)
                        break;
                dma_unmap_single(dev, s->dma_address, s->dma_length, dir);
        }
@@ -364,6 +354,7 @@ static int __dma_map_cont(struct scatterlist *sg, int start, int stopat,
                
                BUG_ON(i > start && s->offset);
                if (i == start) {
+                       *sout = *s; 
                        sout->dma_address = iommu_bus_base;
                        sout->dma_address += iommu_page*PAGE_SIZE + s->offset;
                        sout->dma_length = s->length;
@@ -390,6 +381,7 @@ static inline int dma_map_cont(struct scatterlist *sg, int start, int stopat,
 {
        if (!need) { 
                BUG_ON(stopat - start != 1);
+               *sout = sg[start]; 
                sout->dma_length = sg[start].length; 
                return 0;
        } 
@@ -632,17 +624,13 @@ static int __init pci_iommu_init(void)
                (agp_copy_info(agp_bridge, &info) < 0);
 #endif 
 
-       if (swiotlb) { 
-               no_iommu = 1;
+       if (swiotlb)
                return -1; 
-       } 
-       
+
        if (no_iommu ||
            (!force_iommu && end_pfn <= MAX_DMA32_PFN) ||
            !iommu_aperture ||
            (no_agp && init_k8_gatt(&info) < 0)) {
-               no_iommu = 1;
-               no_iommu_init();
                printk(KERN_INFO "PCI-DMA: Disabling IOMMU.\n");
                if (end_pfn > MAX_DMA32_PFN) {
                        printk(KERN_ERR "WARNING more than 4GB of memory "

diff --git a/include/asm-x86_64/pci.h b/include/asm-x86_64/pci.h
index fd03e15..8a05af2 100644 (file)
--- a/include/asm-x86_64/pci.h
+++ b/include/asm-x86_64/pci.h
@@ -19,8 +19,6 @@ extern unsigned int pcibios_assign_all_busses(void);
 #endif
 #define pcibios_scan_all_fns(a, b)     0
 
-extern int no_iommu, force_iommu;
-
 extern unsigned long pci_mem_start;
 #define PCIBIOS_MIN_IO         0x1000
 #define PCIBIOS_MIN_MEM                (pci_mem_start)