From 8a94ade4ce6df22006b96c5c9a8d6d12fce67585 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 24 Mar 2015 14:54:56 +0000 Subject: [PATCH] iommu/vt-d: Add initial support for PASID tables Add CONFIG_INTEL_IOMMU_SVM, and allocate PASID tables on supported hardware. Signed-off-by: David Woodhouse --- drivers/iommu/Kconfig | 8 ++++++ drivers/iommu/Makefile | 1 + drivers/iommu/intel-iommu.c | 14 ++++++++++ drivers/iommu/intel-svm.c | 65 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/intel-iommu.h | 15 +++++++++++ 5 files changed, 103 insertions(+) create mode 100644 drivers/iommu/intel-svm.c diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index d9da766719c8..e3b2c2e62e32 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -135,6 +135,14 @@ config INTEL_IOMMU and include PCI device scope covered by these DMA remapping devices. +config INTEL_IOMMU_SVM + bool "Support for Shared Virtual Memory with Intel IOMMU" + depends on INTEL_IOMMU && X86 + help + Shared Virtual Memory (SVM) provides a facility for devices + to access DMA resources through process address space by + means of a Process Address Space ID (PASID). + config INTEL_IOMMU_DEFAULT_ON def_bool y prompt "Enable Intel DMA Remapping Devices by default" diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index c6dcc513d711..dc6f511f45a3 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -12,6 +12,7 @@ obj-$(CONFIG_ARM_SMMU) += arm-smmu.o obj-$(CONFIG_ARM_SMMU_V3) += arm-smmu-v3.o obj-$(CONFIG_DMAR_TABLE) += dmar.o obj-$(CONFIG_INTEL_IOMMU) += intel-iommu.o +obj-$(CONFIG_INTEL_IOMMU_SVM) += intel-svm.o obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o obj-$(CONFIG_IRQ_REMAP) += intel_irq_remapping.o irq_remapping.o obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 6a01735f4df3..ab99fcfd9f2d 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1680,6 +1680,11 @@ static void free_dmar_iommu(struct intel_iommu *iommu) /* free context mapping */ free_context_table(iommu); + +#ifdef CONFIG_INTEL_IOMMU_SVM + if (pasid_enabled(iommu)) + intel_svm_free_pasid_tables(iommu); +#endif } static struct dmar_domain *alloc_domain(int flags) @@ -3107,6 +3112,10 @@ static int __init init_dmars(void) if (!ecap_pass_through(iommu->ecap)) hw_pass_through = 0; +#ifdef CONFIG_INTEL_IOMMU_SVM + if (pasid_enabled(iommu)) + intel_svm_alloc_pasid_tables(iommu); +#endif } if (iommu_pass_through) @@ -4122,6 +4131,11 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru) if (ret) goto out; +#ifdef CONFIG_INTEL_IOMMU_SVM + if (pasid_enabled(iommu)) + intel_svm_alloc_pasid_tables(iommu); +#endif + if (dmaru->ignored) { /* * we always have to disable PMRs or DMA may fail on this device diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c new file mode 100644 index 000000000000..5b42a95b3f80 --- /dev/null +++ b/drivers/iommu/intel-svm.c @@ -0,0 +1,65 @@ +/* + * Copyright © 2015 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * Authors: David Woodhouse + */ + +#include + +int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu) +{ + struct page *pages; + int order; + + order = ecap_pss(iommu->ecap) + 7 - PAGE_SHIFT; + if (order < 0) + order = 0; + + pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order); + if (!pages) { + pr_warn("IOMMU: %s: Failed to allocate PASID table\n", + iommu->name); + return -ENOMEM; + } + iommu->pasid_table = page_address(pages); + pr_info("%s: Allocated order %d PASID table.\n", iommu->name, order); + + if (ecap_dis(iommu->ecap)) { + pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order); + if (pages) + iommu->pasid_state_table = page_address(pages); + else + pr_warn("IOMMU: %s: Failed to allocate PASID state table\n", + iommu->name); + } + + return 0; +} + +int intel_svm_free_pasid_tables(struct intel_iommu *iommu) +{ + int order; + + order = ecap_pss(iommu->ecap) + 7 - PAGE_SHIFT; + if (order < 0) + order = 0; + + if (iommu->pasid_table) { + free_pages((unsigned long)iommu->pasid_table, order); + iommu->pasid_table = NULL; + } + if (iommu->pasid_state_table) { + free_pages((unsigned long)iommu->pasid_state_table, order); + iommu->pasid_state_table = NULL; + } + return 0; +} diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index 1d69c1d3aa9a..0f38e60d40ad 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -325,6 +325,9 @@ enum { #define VTD_FLAG_TRANS_PRE_ENABLED (1 << 0) #define VTD_FLAG_IRQ_REMAP_PRE_ENABLED (1 << 1) +struct pasid_entry; +struct pasid_state_entry; + struct intel_iommu { void __iomem *reg; /* Pointer to hardware regs, virtual addr */ u64 reg_phys; /* physical address of hw register set */ @@ -348,6 +351,15 @@ struct intel_iommu { struct iommu_flush flush; #endif +#ifdef CONFIG_INTEL_IOMMU_SVM + /* These are large and need to be contiguous, so we allocate just + * one for now. We'll maybe want to rethink that if we truly give + * devices away to userspace processes (e.g. for DPDK) and don't + * want to trust that userspace will use *only* the PASID it was + * told to. But while it's all driver-arbitrated, we're fine. */ + struct pasid_entry *pasid_table; + struct pasid_state_entry *pasid_state_table; +#endif struct q_inval *qi; /* Queued invalidation info */ u32 *iommu_state; /* Store iommu states between suspend and resume.*/ @@ -387,6 +399,9 @@ extern int qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu); extern int dmar_ir_support(void); +extern int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu); +extern int intel_svm_free_pasid_tables(struct intel_iommu *iommu); + extern const struct attribute_group *intel_iommu_groups[]; #endif -- 2.11.4.GIT