From 7d3b03ce7bff9d39ebaee1bb8de1968c4434b883 Mon Sep 17 00:00:00 2001 From: "Keshavamurthy, Anil S" Date: Sun, 21 Oct 2007 16:41:53 -0700 Subject: Intel IOMMU: Intel iommu cmdline option - forcedac Introduce intel_iommu=forcedac commandline option. This option is helpful to verify the pci device capability of handling physical dma'able address greater than 4G. Signed-off-by: Anil S Keshavamurthy Cc: Andi Kleen Cc: Peter Zijlstra Cc: Muli Ben-Yehuda Cc: "Siddha, Suresh B" Cc: Arjan van de Ven Cc: Ashok Raj Cc: "David S. Miller" Cc: Christoph Lameter Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/pci/intel-iommu.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 05630b44db..cb24defdb6 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -54,6 +54,7 @@ static void domain_remove_dev_info(struct dmar_domain *domain); static int dmar_disabled; static int __initdata dmar_map_gfx = 1; +static int dmar_forcedac; #define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1)) static DEFINE_SPINLOCK(device_domain_lock); @@ -71,6 +72,10 @@ static int __init intel_iommu_setup(char *str) dmar_map_gfx = 0; printk(KERN_INFO "Intel-IOMMU: disable GFX device mapping\n"); + } else if (!strncmp(str, "forcedac", 8)) { + printk (KERN_INFO + "Intel-IOMMU: Forcing DAC for PCI devices\n"); + dmar_forcedac = 1; } str += strcspn(str, ","); @@ -1558,7 +1563,7 @@ static dma_addr_t __intel_map_single(struct device *dev, void *addr, start_addr = IOVA_START_ADDR; - if (pdev->dma_mask <= DMA_32BIT_MASK) { + if ((pdev->dma_mask <= DMA_32BIT_MASK) || (dmar_forcedac)) { iova = iommu_alloc_iova(domain, addr, size, start_addr, pdev->dma_mask); } else { -- cgit v1.2.2