diff options
| -rw-r--r-- | arch/x86/kernel/pci-dma.c | 44 | ||||
| -rw-r--r-- | arch/x86/kernel/pci-dma_32.c | 24 | ||||
| -rw-r--r-- | arch/x86/kernel/pci-dma_64.c | 44 |
3 files changed, 45 insertions, 67 deletions
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 48cccbe51aa..7d3bd652c36 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -14,6 +14,8 @@ EXPORT_SYMBOL(forbid_dac); const struct dma_mapping_ops *dma_ops; EXPORT_SYMBOL(dma_ops); +int iommu_sac_force __read_mostly = 0; + #ifdef CONFIG_IOMMU_DEBUG int panic_on_overflow __read_mostly = 1; int force_iommu __read_mostly = 1; @@ -103,6 +105,48 @@ void __init pci_iommu_alloc(void) } #endif +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); + + static int __init pci_iommu_init(void) { #ifdef CONFIG_CALGARY_IOMMU diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c index 6543bb30b65..1d4091af441 100644 --- a/arch/x86/kernel/pci-dma_32.c +++ b/arch/x86/kernel/pci-dma_32.c @@ -155,30 +155,6 @@ void *dma_mark_declared_memory_occupied(struct device *dev, EXPORT_SYMBOL(dma_mark_declared_memory_occupied); #ifdef CONFIG_PCI -/* Many VIA bridges seem to corrupt data for DAC. Disable it here */ - -int -dma_supported(struct device *dev, u64 mask) -{ - /* - * we fall back to GFP_DMA when the mask isn't all 1s, - * so we can't guarantee allocations that must be - * within a tighter range than GFP_DMA.. - */ - if (mask < 0x00ffffff) - return 0; - - /* Work around chipset bugs */ - if (forbid_dac > 0 && mask > 0xffffffffULL) - return 0; - - if (dma_ops->dma_supported) - return dma_ops->dma_supported(dev, mask); - - return 1; -} -EXPORT_SYMBOL(dma_supported); - static int check_iommu(char *s) { if (!strcmp(s, "usedac")) { 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. |