diff options
Diffstat (limited to 'kernel/arch/x86/xen/pci-swiotlb-xen.c')
-rw-r--r-- | kernel/arch/x86/xen/pci-swiotlb-xen.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/kernel/arch/x86/xen/pci-swiotlb-xen.c b/kernel/arch/x86/xen/pci-swiotlb-xen.c new file mode 100644 index 000000000..0e98e5d24 --- /dev/null +++ b/kernel/arch/x86/xen/pci-swiotlb-xen.c @@ -0,0 +1,109 @@ +/* Glue code to lib/swiotlb-xen.c */ + +#include <linux/dma-mapping.h> +#include <linux/pci.h> +#include <xen/swiotlb-xen.h> + +#include <asm/xen/hypervisor.h> +#include <xen/xen.h> +#include <asm/iommu_table.h> + + +#include <asm/xen/swiotlb-xen.h> +#ifdef CONFIG_X86_64 +#include <asm/iommu.h> +#include <asm/dma.h> +#endif +#include <linux/export.h> + +int xen_swiotlb __read_mostly; + +static struct dma_map_ops xen_swiotlb_dma_ops = { + .mapping_error = xen_swiotlb_dma_mapping_error, + .alloc = xen_swiotlb_alloc_coherent, + .free = xen_swiotlb_free_coherent, + .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu, + .sync_single_for_device = xen_swiotlb_sync_single_for_device, + .sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = xen_swiotlb_sync_sg_for_device, + .map_sg = xen_swiotlb_map_sg_attrs, + .unmap_sg = xen_swiotlb_unmap_sg_attrs, + .map_page = xen_swiotlb_map_page, + .unmap_page = xen_swiotlb_unmap_page, + .dma_supported = xen_swiotlb_dma_supported, +}; + +/* + * pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary + * + * This returns non-zero if we are forced to use xen_swiotlb (by the boot + * option). + */ +int __init pci_xen_swiotlb_detect(void) +{ + + if (!xen_pv_domain()) + return 0; + + /* If running as PV guest, either iommu=soft, or swiotlb=force will + * activate this IOMMU. If running as PV privileged, activate it + * irregardless. + */ + if ((xen_initial_domain() || swiotlb || swiotlb_force)) + xen_swiotlb = 1; + + /* If we are running under Xen, we MUST disable the native SWIOTLB. + * Don't worry about swiotlb_force flag activating the native, as + * the 'swiotlb' flag is the only one turning it on. */ + swiotlb = 0; + +#ifdef CONFIG_X86_64 + /* pci_swiotlb_detect_4gb turns on native SWIOTLB if no_iommu == 0 + * (so no iommu=X command line over-writes). + * Considering that PV guests do not want the *native SWIOTLB* but + * only Xen SWIOTLB it is not useful to us so set no_iommu=1 here. + */ + if (max_pfn > MAX_DMA32_PFN) + no_iommu = 1; +#endif + return xen_swiotlb; +} + +void __init pci_xen_swiotlb_init(void) +{ + if (xen_swiotlb) { + xen_swiotlb_init(1, true /* early */); + dma_ops = &xen_swiotlb_dma_ops; + +#ifdef CONFIG_PCI + /* Make sure ACS will be enabled */ + pci_request_acs(); +#endif + } +} + +int pci_xen_swiotlb_init_late(void) +{ + int rc; + + if (xen_swiotlb) + return 0; + + rc = xen_swiotlb_init(1, false /* late */); + if (rc) + return rc; + + dma_ops = &xen_swiotlb_dma_ops; +#ifdef CONFIG_PCI + /* Make sure ACS will be enabled */ + pci_request_acs(); +#endif + + return 0; +} +EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late); + +IOMMU_INIT_FINISH(pci_xen_swiotlb_detect, + NULL, + pci_xen_swiotlb_init, + NULL); |