iommu/vt-d: Add basic SVM PASID support

This provides basic PASID support for endpoint devices, tested with a
version of the i915 driver.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

3 files changed, 152 insertions, 5 deletions

diff --git a/include/linux/dma_remapping.h b/include/linux/dma_remapping.h
index 7ac17f57250e..0e114bfabeed 100644
--- a/include/linux/dma_remapping.h
+++ b/include/linux/dma_remapping.h
@@ -20,6 +20,13 @@
 #define CONTEXT_TT_MULTI_LEVEL	0
 #define CONTEXT_TT_DEV_IOTLB	1
 #define CONTEXT_TT_PASS_THROUGH 2
+/* Extended context entry types */
+#define CONTEXT_TT_PT_PASID	4
+#define CONTEXT_TT_PT_PASID_DEV_IOTLB 5
+#define CONTEXT_TT_MASK (7ULL << 2)
+
+#define CONTEXT_PRS		(1ULL << 9)
+#define CONTEXT_PASIDE		(1ULL << 11)
 
 struct intel_iommu;
 struct dmar_domain;
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 0f38e60d40ad..46add607567b 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -1,5 +1,9 @@
 /*
- * Copyright (c) 2006, Intel Corporation.
+ * Copyright © 2006-2015, Intel Corporation.
+ *
+ * Authors: Ashok Raj <ashok.raj@intel.com>
+ *          Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ *          David Woodhouse <David.Woodhouse@intel.com>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -13,10 +17,6 @@
  * You should have received a copy of the GNU General Public License along with
  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  * Place - Suite 330, Boston, MA 02111-1307 USA.
- *
- * Copyright (C) 2006-2008 Intel Corporation
- * Author: Ashok Raj <ashok.raj@intel.com>
- * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  */
 
 #ifndef _INTEL_IOMMU_H_
@@ -25,7 +25,10 @@
 #include <linux/types.h>
 #include <linux/iova.h>
 #include <linux/io.h>
+#include <linux/idr.h>
 #include <linux/dma_remapping.h>
+#include <linux/mmu_notifier.h>
+#include <linux/list.h>
 #include <asm/cacheflush.h>
 #include <asm/iommu.h>
 
@@ -251,6 +254,9 @@ enum {
 #define QI_DIOTLB_TYPE		0x3
 #define QI_IEC_TYPE		0x4
 #define QI_IWD_TYPE		0x5
+#define QI_EIOTLB_TYPE		0x6
+#define QI_PC_TYPE		0x7
+#define QI_DEIOTLB_TYPE		0x8
 
 #define QI_IEC_SELECTIVE	(((u64)1) << 4)
 #define QI_IEC_IIDEX(idx)	(((u64)(idx & 0xffff) << 32))
@@ -278,6 +284,34 @@ enum {
 #define QI_DEV_IOTLB_SIZE	1
 #define QI_DEV_IOTLB_MAX_INVS	32
 
+#define QI_PC_PASID(pasid)	(((u64)pasid) << 32)
+#define QI_PC_DID(did)		(((u64)did) << 16)
+#define QI_PC_GRAN(gran)	(((u64)gran) << 4)
+
+#define QI_PC_ALL_PASIDS	(QI_PC_TYPE | QI_PC_GRAN(0))
+#define QI_PC_PASID_SEL		(QI_PC_TYPE | QI_PC_GRAN(1))
+
+#define QI_EIOTLB_ADDR(addr)	((u64)(addr) & VTD_PAGE_MASK)
+#define QI_EIOTLB_GL(gl)	(((u64)gl) << 7)
+#define QI_EIOTLB_IH(ih)	(((u64)ih) << 6)
+#define QI_EIOTLB_AM(am)	(((u64)am))
+#define QI_EIOTLB_PASID(pasid) 	(((u64)pasid) << 32)
+#define QI_EIOTLB_DID(did)	(((u64)did) << 16)
+#define QI_EIOTLB_GRAN(gran) 	(((u64)gran) << 4)
+
+#define QI_DEV_EIOTLB_ADDR(a)	((u64)(a) & VTD_PAGE_MASK)
+#define QI_DEV_EIOTLB_SIZE	(((u64)1) << 11)
+#define QI_DEV_EIOTLB_GLOB(g)	((u64)g)
+#define QI_DEV_EIOTLB_PASID(p)	(((u64)p) << 32)
+#define QI_DEV_EIOTLB_SID(sid)	((u64)((sid) & 0xffff) << 32)
+#define QI_DEV_EIOTLB_QDEP(qd)	(((qd) & 0x1f) << 16)
+#define QI_DEV_EIOTLB_MAX_INVS	32
+
+#define QI_GRAN_ALL_ALL			0
+#define QI_GRAN_NONG_ALL		1
+#define QI_GRAN_NONG_PASID		2
+#define QI_GRAN_PSI_PASID		3
+
 struct qi_desc {
 	u64 low, high;
 };
@@ -359,6 +393,7 @@ struct intel_iommu {
 	 * told to. But while it's all driver-arbitrated, we're fine. */
 	struct pasid_entry *pasid_table;
 	struct pasid_state_entry *pasid_state_table;
+	struct idr pasid_idr;
 #endif
 	struct q_inval  *qi;            /* Queued invalidation info */
 	u32 *iommu_state; /* Store iommu states between suspend and resume.*/
@@ -399,9 +434,32 @@ extern int qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu);
 
 extern int dmar_ir_support(void);
 
+#ifdef CONFIG_INTEL_IOMMU_SVM
 extern int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu);
 extern int intel_svm_free_pasid_tables(struct intel_iommu *iommu);
 
+struct intel_svm_dev {
+	struct list_head list;
+	struct rcu_head rcu;
+	struct device *dev;
+	int users;
+	u16 did;
+	u16 dev_iotlb:1;
+	u16 sid, qdep;
+};
+
+struct intel_svm {
+	struct mmu_notifier notifier;
+	struct mm_struct *mm;
+	struct intel_iommu *iommu;
+	int pasid;
+	struct list_head devs;
+};
+
+extern int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sdev);
+extern struct intel_iommu *intel_svm_device_to_iommu(struct device *dev);
+#endif
+
 extern const struct attribute_group *intel_iommu_groups[];
 
 #endif
diff --git a/include/linux/intel-svm.h b/include/linux/intel-svm.h
new file mode 100644
index 000000000000..42f80ad7a7a0
--- /dev/null
+++ b/include/linux/intel-svm.h
@@ -0,0 +1,82 @@
+/*
+ * Copyright © 2015 Intel Corporation.
+ *
+ * Authors: David Woodhouse <David.Woodhouse@intel.com>
+ *
+ * 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.
+ */
+
+#ifndef __INTEL_SVM_H__
+#define __INTEL_SVM_H__
+
+#ifdef CONFIG_INTEL_IOMMU_SVM
+
+struct device;
+
+/**
+ * intel_svm_bind_mm() - Bind the current process to a PASID
+ * @dev:	Device to be granted acccess
+ * @pasid:	Address for allocated PASID
+ *
+ * This function attempts to enable PASID support for the given device.
+ * If the @pasid argument is non-%NULL, a PASID is allocated for access
+ * to the MM of the current process.
+ *
+ * By using a %NULL value for the @pasid argument, this function can
+ * be used to simply validate that PASID support is available for the
+ * given device — i.e. that it is behind an IOMMU which has the
+ * requisite support, and is enabled.
+ *
+ * Page faults are handled transparently by the IOMMU code, and there
+ * should be no need for the device driver to be involved. If a page
+ * fault cannot be handled (i.e. is an invalid address rather than
+ * just needs paging in), then the page request will be completed by
+ * the core IOMMU code with appropriate status, and the device itself
+ * can then report the resulting fault to its driver via whatever
+ * mechanism is appropriate.
+ *
+ * Multiple calls from the same process may result in the same PASID
+ * being re-used. A reference count is kept.
+ */
+extern int intel_svm_bind_mm(struct device *dev, int *pasid);
+
+/**
+ * intel_svm_unbind_mm() - Unbind a specified PASID
+ * @dev:	Device for which PASID was allocated
+ * @pasid:	PASID value to be unbound
+ *
+ * This function allows a PASID to be retired when the device no
+ * longer requires access to the address space of a given process.
+ *
+ * If the use count for the PASID in question reaches zero, the
+ * PASID is revoked and may no longer be used by hardware.
+ *
+ * Device drivers are required to ensure that no access (including
+ * page requests) is currently outstanding for the PASID in question,
+ * before calling this function.
+ */
+extern int intel_svm_unbind_mm(struct device *dev, int pasid);
+
+#else /* CONFIG_INTEL_IOMMU_SVM */
+
+static inline int intel_svm_bind_mm(struct device *dev, int *pasid)
+{
+	return -ENOSYS;
+}
+
+static inline int intel_svm_unbind_mm(struct device *dev, int pasid)
+{
+	BUG();
+}
+#endif /* CONFIG_INTEL_IOMMU_SVM */
+
+#define intel_svm_available(dev) (!intel_svm_bind_mm((dev), NULL))
+
+#endif /* __INTEL_SVM_H__ */