diff options
Diffstat (limited to 'arch/x86/kernel/pci-dma_64.c')
| -rw-r--r-- | arch/x86/kernel/pci-dma_64.c | 44 |
1 files changed, 1 insertions, 43 deletions
diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c index 7820675a688..c80da76e7e6 100644 --- a/arch/x86/kernel/pci-dma_64.c +++ b/arch/x86/kernel/pci-dma_64.c @@ -24,7 +24,7 @@ EXPORT_SYMBOL(bad_dma_address); int iommu_bio_merge __read_mostly = 0; EXPORT_SYMBOL(iommu_bio_merge); -static int iommu_sac_force __read_mostly = 0; +extern int iommu_sac_force; int no_iommu __read_mostly; /* Set this to 1 if there is a HW IOMMU in the system */ @@ -161,48 +161,6 @@ void dma_free_coherent(struct device *dev, size_t size, } EXPORT_SYMBOL(dma_free_coherent); -int dma_supported(struct device *dev, u64 mask) -{ -#ifdef CONFIG_PCI - if (mask > 0xffffffff && forbid_dac > 0) { - - - - printk(KERN_INFO "PCI: Disallowing DAC for device %s\n", dev->bus_id); - return 0; - } -#endif - - if (dma_ops->dma_supported) - return dma_ops->dma_supported(dev, mask); - - /* Copied from i386. Doesn't make much sense, because it will - only work for pci_alloc_coherent. - The caller just has to use GFP_DMA in this case. */ - if (mask < DMA_24BIT_MASK) - return 0; - - /* Tell the device to use SAC when IOMMU force is on. This - allows the driver to use cheaper accesses in some cases. - - Problem with this is that if we overflow the IOMMU area and - return DAC as fallback address the device may not handle it - correctly. - - As a special case some controllers have a 39bit address - mode that is as efficient as 32bit (aic79xx). Don't force - SAC for these. Assume all masks <= 40 bits are of this - type. Normally this doesn't make any difference, but gives - more gentle handling of IOMMU overflow. */ - if (iommu_sac_force && (mask >= DMA_40BIT_MASK)) { - printk(KERN_INFO "%s: Force SAC with mask %Lx\n", dev->bus_id,mask); - return 0; - } - - return 1; -} -EXPORT_SYMBOL(dma_supported); - /* * See <Documentation/x86_64/boot-options.txt> for the iommu kernel parameter * documentation. |