This config option (DMAR_FLPY_WA) sets up 1:1 mapping for the floppy device so that the floppy device which does not use DMA api's will continue to work. Once the floppy driver starts using DMA api's this config option can be turn off or this patch can be yanked out of kernel at that time. Signed-off-by: Anil S Keshavamurthy --- arch/x86_64/Kconfig | 10 ++++++++++ drivers/pci/intel-iommu.c | 22 ++++++++++++++++++++++ drivers/pci/intel-iommu.h | 7 +++++++ 3 files changed, 39 insertions(+) Index: linux-2.6.22-rc4-mm2/arch/x86_64/Kconfig =================================================================== --- linux-2.6.22-rc4-mm2.orig/arch/x86_64/Kconfig 2007-06-18 15:45:08.000000000 -0700 +++ linux-2.6.22-rc4-mm2/arch/x86_64/Kconfig 2007-06-18 15:45:09.000000000 -0700 @@ -752,6 +752,16 @@ all the OS visible memory. Hence the driver can continue to use physical addresses for DMA. +config DMAR_FLPY_WA + bool "Support for Floppy disk workaround" + depends on DMAR + default y + help + Floppy disk drivers are know to by pass dma api calls + their by failing to work when IOMMU is enabled. This + work around will setup a 1 to 1 mappings for the first + 16M to make floppy(isa device) work. + source "drivers/pci/pcie/Kconfig" source "drivers/pci/Kconfig" Index: linux-2.6.22-rc4-mm2/drivers/pci/intel-iommu.c =================================================================== --- linux-2.6.22-rc4-mm2.orig/drivers/pci/intel-iommu.c 2007-06-18 15:45:08.000000000 -0700 +++ linux-2.6.22-rc4-mm2/drivers/pci/intel-iommu.c 2007-06-18 15:45:09.000000000 -0700 @@ -1631,6 +1631,26 @@ } #endif +#ifdef CONFIG_DMAR_FLPY_WA +static inline void iommu_prepare_isa(void) +{ + struct pci_dev *pdev = NULL; + int ret; + + pdev = pci_get_class (PCI_CLASS_BRIDGE_ISA << 8, NULL); + if (!pdev) + return; + + printk (KERN_INFO "IOMMU: Prepare 0-16M unity mapping for LPC\n"); + ret = iommu_prepare_identity_map(pdev, 0, 16*1024*1024); + + if (ret) + printk ("IOMMU: Failed to create 0-64M identity map, \ + Floppy might not work\n"); + +} +#endif + int __init init_dmars(void) { struct dmar_drhd_unit *drhd; @@ -1696,6 +1716,8 @@ iommu_prepare_gfx_mapping(); + iommu_prepare_isa(); + /* * for each drhd * enable fault log Index: linux-2.6.22-rc4-mm2/drivers/pci/intel-iommu.h =================================================================== --- linux-2.6.22-rc4-mm2.orig/drivers/pci/intel-iommu.h 2007-06-18 15:45:08.000000000 -0700 +++ linux-2.6.22-rc4-mm2/drivers/pci/intel-iommu.h 2007-06-18 15:45:09.000000000 -0700 @@ -322,4 +322,11 @@ } #endif /* !CONFIG_DMAR_GFX_WA */ +#ifndef CONFIG_DMAR_FLPY_WA +static inline void iommu_prepare_isa(void) +{ + return; +} +#endif /* !CONFIG_DMAR_FLPY_WA */ + #endif -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/