diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/pci-dma.c | 114 |
1 files changed, 93 insertions, 21 deletions
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index de234e7a8962..30bbe4abb5d6 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -7,13 +7,16 @@ #include <linux/memblock.h> #include <linux/gfp.h> #include <linux/pci.h> +#include <linux/amd-iommu.h> #include <asm/proto.h> #include <asm/dma.h> #include <asm/iommu.h> #include <asm/gart.h> #include <asm/x86_init.h> -#include <asm/iommu_table.h> + +#include <xen/xen.h> +#include <xen/swiotlb-xen.h> static bool disable_dac_quirk __read_mostly; @@ -34,24 +37,90 @@ int no_iommu __read_mostly; /* Set this to 1 if there is a HW IOMMU in the system */ int iommu_detected __read_mostly = 0; -extern struct iommu_table_entry __iommu_table[], __iommu_table_end[]; +#ifdef CONFIG_SWIOTLB +bool x86_swiotlb_enable; +static unsigned int x86_swiotlb_flags; + +static void __init pci_swiotlb_detect(void) +{ + /* don't initialize swiotlb if iommu=off (no_iommu=1) */ + if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN) + x86_swiotlb_enable = true; + + /* + * Set swiotlb to 1 so that bounce buffers are allocated and used for + * devices that can't support DMA to encrypted memory. + */ + if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) + x86_swiotlb_enable = true; + + /* + * Guest with guest memory encryption currently perform all DMA through + * bounce buffers as the hypervisor can't access arbitrary VM memory + * that is not explicitly shared with it. + */ + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) { + x86_swiotlb_enable = true; + x86_swiotlb_flags |= SWIOTLB_FORCE; + } +} +#else +static inline void __init pci_swiotlb_detect(void) +{ +} +#define x86_swiotlb_flags 0 +#endif /* CONFIG_SWIOTLB */ + +#ifdef CONFIG_SWIOTLB_XEN +static void __init pci_xen_swiotlb_init(void) +{ + if (!xen_initial_domain() && !x86_swiotlb_enable) + return; + x86_swiotlb_enable = true; + x86_swiotlb_flags |= SWIOTLB_ANY; + swiotlb_init_remap(true, x86_swiotlb_flags, xen_swiotlb_fixup); + dma_ops = &xen_swiotlb_dma_ops; + if (IS_ENABLED(CONFIG_PCI)) + pci_request_acs(); +} + +int pci_xen_swiotlb_init_late(void) +{ + if (dma_ops == &xen_swiotlb_dma_ops) + return 0; + + /* we can work with the default swiotlb */ + if (!io_tlb_default_mem.nslabs) { + int rc = swiotlb_init_late(swiotlb_size_or_default(), + GFP_KERNEL, xen_swiotlb_fixup); + if (rc < 0) + return rc; + } + + /* XXX: this switches the dma ops under live devices! */ + dma_ops = &xen_swiotlb_dma_ops; + if (IS_ENABLED(CONFIG_PCI)) + pci_request_acs(); + return 0; +} +EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late); +#else +static inline void __init pci_xen_swiotlb_init(void) +{ +} +#endif /* CONFIG_SWIOTLB_XEN */ void __init pci_iommu_alloc(void) { - struct iommu_table_entry *p; - - sort_iommu_table(__iommu_table, __iommu_table_end); - check_iommu_entries(__iommu_table, __iommu_table_end); - - for (p = __iommu_table; p < __iommu_table_end; p++) { - if (p && p->detect && p->detect() > 0) { - p->flags |= IOMMU_DETECTED; - if (p->early_init) - p->early_init(); - if (p->flags & IOMMU_FINISH_IF_DETECTED) - break; - } + if (xen_pv_domain()) { + pci_xen_swiotlb_init(); + return; } + pci_swiotlb_detect(); + gart_iommu_hole_init(); + amd_iommu_detect(); + detect_intel_iommu(); + swiotlb_init(x86_swiotlb_enable, x86_swiotlb_flags); } /* @@ -102,7 +171,7 @@ static __init int iommu_setup(char *p) } #ifdef CONFIG_SWIOTLB if (!strncmp(p, "soft", 4)) - swiotlb = 1; + x86_swiotlb_enable = true; #endif if (!strncmp(p, "pt", 2)) iommu_set_default_passthrough(true); @@ -121,14 +190,17 @@ early_param("iommu", iommu_setup); static int __init pci_iommu_init(void) { - struct iommu_table_entry *p; - x86_init.iommu.iommu_init(); - for (p = __iommu_table; p < __iommu_table_end; p++) { - if (p && (p->flags & IOMMU_DETECTED) && p->late_init) - p->late_init(); +#ifdef CONFIG_SWIOTLB + /* An IOMMU turned us off. */ + if (x86_swiotlb_enable) { + pr_info("PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n"); + swiotlb_print_info(); + } else { + swiotlb_exit(); } +#endif return 0; } |