David Woodhouse | 2f26e0a | 2015-09-09 11:40:47 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright © 2015 Intel Corporation. |
| 3 | * |
| 4 | * Authors: David Woodhouse <David.Woodhouse@intel.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify it |
| 7 | * under the terms and conditions of the GNU General Public License, |
| 8 | * version 2, as published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope it will be useful, but WITHOUT |
| 11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 13 | * more details. |
| 14 | */ |
| 15 | |
| 16 | #ifndef __INTEL_SVM_H__ |
| 17 | #define __INTEL_SVM_H__ |
| 18 | |
| 19 | #ifdef CONFIG_INTEL_IOMMU_SVM |
| 20 | |
| 21 | struct device; |
| 22 | |
David Woodhouse | 0204a49 | 2015-10-13 17:18:10 +0100 | [diff] [blame^] | 23 | struct svm_dev_ops { |
| 24 | void (*fault_cb)(struct device *dev, int pasid, u64 address, |
| 25 | u32 private, int rwxp, int response); |
| 26 | }; |
| 27 | |
| 28 | /* Values for rxwp in fault_cb callback */ |
| 29 | #define SVM_REQ_READ (1<<3) |
| 30 | #define SVM_REQ_WRITE (1<<2) |
| 31 | #define SVM_REQ_EXEC (1<<1) |
| 32 | #define SVM_REQ_PRIV (1<<0) |
| 33 | |
David Woodhouse | 2f26e0a | 2015-09-09 11:40:47 +0100 | [diff] [blame] | 34 | /** |
| 35 | * intel_svm_bind_mm() - Bind the current process to a PASID |
| 36 | * @dev: Device to be granted acccess |
| 37 | * @pasid: Address for allocated PASID |
David Woodhouse | 0204a49 | 2015-10-13 17:18:10 +0100 | [diff] [blame^] | 38 | * @flags: Flags. Later for requesting supervisor mode, etc. |
| 39 | * @ops: Callbacks to device driver |
David Woodhouse | 2f26e0a | 2015-09-09 11:40:47 +0100 | [diff] [blame] | 40 | * |
| 41 | * This function attempts to enable PASID support for the given device. |
| 42 | * If the @pasid argument is non-%NULL, a PASID is allocated for access |
| 43 | * to the MM of the current process. |
| 44 | * |
| 45 | * By using a %NULL value for the @pasid argument, this function can |
| 46 | * be used to simply validate that PASID support is available for the |
| 47 | * given device — i.e. that it is behind an IOMMU which has the |
| 48 | * requisite support, and is enabled. |
| 49 | * |
| 50 | * Page faults are handled transparently by the IOMMU code, and there |
| 51 | * should be no need for the device driver to be involved. If a page |
| 52 | * fault cannot be handled (i.e. is an invalid address rather than |
| 53 | * just needs paging in), then the page request will be completed by |
| 54 | * the core IOMMU code with appropriate status, and the device itself |
| 55 | * can then report the resulting fault to its driver via whatever |
| 56 | * mechanism is appropriate. |
| 57 | * |
| 58 | * Multiple calls from the same process may result in the same PASID |
| 59 | * being re-used. A reference count is kept. |
| 60 | */ |
David Woodhouse | 0204a49 | 2015-10-13 17:18:10 +0100 | [diff] [blame^] | 61 | extern int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, |
| 62 | struct svm_dev_ops *ops); |
David Woodhouse | 2f26e0a | 2015-09-09 11:40:47 +0100 | [diff] [blame] | 63 | |
| 64 | /** |
| 65 | * intel_svm_unbind_mm() - Unbind a specified PASID |
| 66 | * @dev: Device for which PASID was allocated |
| 67 | * @pasid: PASID value to be unbound |
| 68 | * |
| 69 | * This function allows a PASID to be retired when the device no |
| 70 | * longer requires access to the address space of a given process. |
| 71 | * |
| 72 | * If the use count for the PASID in question reaches zero, the |
| 73 | * PASID is revoked and may no longer be used by hardware. |
| 74 | * |
| 75 | * Device drivers are required to ensure that no access (including |
| 76 | * page requests) is currently outstanding for the PASID in question, |
| 77 | * before calling this function. |
| 78 | */ |
| 79 | extern int intel_svm_unbind_mm(struct device *dev, int pasid); |
| 80 | |
| 81 | #else /* CONFIG_INTEL_IOMMU_SVM */ |
| 82 | |
David Woodhouse | 0204a49 | 2015-10-13 17:18:10 +0100 | [diff] [blame^] | 83 | static inline int intel_svm_bind_mm(struct device *dev, int *pasid, |
| 84 | int flags, struct svm_dev_ops *ops) |
David Woodhouse | 2f26e0a | 2015-09-09 11:40:47 +0100 | [diff] [blame] | 85 | { |
| 86 | return -ENOSYS; |
| 87 | } |
| 88 | |
| 89 | static inline int intel_svm_unbind_mm(struct device *dev, int pasid) |
| 90 | { |
| 91 | BUG(); |
| 92 | } |
| 93 | #endif /* CONFIG_INTEL_IOMMU_SVM */ |
| 94 | |
David Woodhouse | 0204a49 | 2015-10-13 17:18:10 +0100 | [diff] [blame^] | 95 | #define intel_svm_available(dev) (!intel_svm_bind_mm((dev), NULL, 0, NULL)) |
David Woodhouse | 2f26e0a | 2015-09-09 11:40:47 +0100 | [diff] [blame] | 96 | |
| 97 | #endif /* __INTEL_SVM_H__ */ |