xref: /linux/include/linux/io-pgtable.h (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __IO_PGTABLE_H
3 #define __IO_PGTABLE_H
4 
5 #include <linux/bitops.h>
6 #include <linux/iommu.h>
7 
8 /*
9  * Public API for use by IOMMU drivers
10  */
11 enum io_pgtable_fmt {
12 	ARM_32_LPAE_S1,
13 	ARM_32_LPAE_S2,
14 	ARM_64_LPAE_S1,
15 	ARM_64_LPAE_S2,
16 	ARM_V7S,
17 	ARM_MALI_LPAE,
18 	AMD_IOMMU_V1,
19 	AMD_IOMMU_V2,
20 	APPLE_DART,
21 	APPLE_DART2,
22 	IO_PGTABLE_NUM_FMTS,
23 };
24 
25 /**
26  * struct iommu_flush_ops - IOMMU callbacks for TLB and page table management.
27  *
28  * @tlb_flush_all:  Synchronously invalidate the entire TLB context.
29  * @tlb_flush_walk: Synchronously invalidate all intermediate TLB state
30  *                  (sometimes referred to as the "walk cache") for a virtual
31  *                  address range.
32  * @tlb_add_page:   Optional callback to queue up leaf TLB invalidation for a
33  *                  single page.  IOMMUs that cannot batch TLB invalidation
34  *                  operations efficiently will typically issue them here, but
35  *                  others may decide to update the iommu_iotlb_gather structure
36  *                  and defer the invalidation until iommu_iotlb_sync() instead.
37  *
38  * Note that these can all be called in atomic context and must therefore
39  * not block.
40  */
41 struct iommu_flush_ops {
42 	void (*tlb_flush_all)(void *cookie);
43 	void (*tlb_flush_walk)(unsigned long iova, size_t size, size_t granule,
44 			       void *cookie);
45 	void (*tlb_add_page)(struct iommu_iotlb_gather *gather,
46 			     unsigned long iova, size_t granule, void *cookie);
47 };
48 
49 /**
50  * struct io_pgtable_cfg - Configuration data for a set of page tables.
51  *
52  * @quirks:        A bitmap of hardware quirks that require some special
53  *                 action by the low-level page table allocator.
54  * @pgsize_bitmap: A bitmap of page sizes supported by this set of page
55  *                 tables.
56  * @ias:           Input address (iova) size, in bits.
57  * @oas:           Output address (paddr) size, in bits.
58  * @coherent_walk  A flag to indicate whether or not page table walks made
59  *                 by the IOMMU are coherent with the CPU caches.
60  * @tlb:           TLB management callbacks for this set of tables.
61  * @iommu_dev:     The device representing the DMA configuration for the
62  *                 page table walker.
63  */
64 struct io_pgtable_cfg {
65 	/*
66 	 * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
67 	 *	stage 1 PTEs, for hardware which insists on validating them
68 	 *	even in	non-secure state where they should normally be ignored.
69 	 *
70 	 * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
71 	 *	IOMMU_NOEXEC flags and map everything with full access, for
72 	 *	hardware which does not implement the permissions of a given
73 	 *	format, and/or requires some format-specific default value.
74 	 *
75 	 * IO_PGTABLE_QUIRK_ARM_MTK_EXT: (ARM v7s format) MediaTek IOMMUs extend
76 	 *	to support up to 35 bits PA where the bit32, bit33 and bit34 are
77 	 *	encoded in the bit9, bit4 and bit5 of the PTE respectively.
78 	 *
79 	 * IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT: (ARM v7s format) MediaTek IOMMUs
80 	 *	extend the translation table base support up to 35 bits PA, the
81 	 *	encoding format is same with IO_PGTABLE_QUIRK_ARM_MTK_EXT.
82 	 *
83 	 * IO_PGTABLE_QUIRK_ARM_TTBR1: (ARM LPAE format) Configure the table
84 	 *	for use in the upper half of a split address space.
85 	 *
86 	 * IO_PGTABLE_QUIRK_ARM_OUTER_WBWA: Override the outer-cacheability
87 	 *	attributes set in the TCR for a non-coherent page-table walker.
88 	 */
89 	#define IO_PGTABLE_QUIRK_ARM_NS			BIT(0)
90 	#define IO_PGTABLE_QUIRK_NO_PERMS		BIT(1)
91 	#define IO_PGTABLE_QUIRK_ARM_MTK_EXT		BIT(3)
92 	#define IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT	BIT(4)
93 	#define IO_PGTABLE_QUIRK_ARM_TTBR1		BIT(5)
94 	#define IO_PGTABLE_QUIRK_ARM_OUTER_WBWA		BIT(6)
95 	unsigned long			quirks;
96 	unsigned long			pgsize_bitmap;
97 	unsigned int			ias;
98 	unsigned int			oas;
99 	bool				coherent_walk;
100 	const struct iommu_flush_ops	*tlb;
101 	struct device			*iommu_dev;
102 
103 	/**
104 	 * @alloc: Custom page allocator.
105 	 *
106 	 * Optional hook used to allocate page tables. If this function is NULL,
107 	 * @free must be NULL too.
108 	 *
109 	 * Memory returned should be zeroed and suitable for dma_map_single() and
110 	 * virt_to_phys().
111 	 *
112 	 * Not all formats support custom page allocators. Before considering
113 	 * passing a non-NULL value, make sure the chosen page format supports
114 	 * this feature.
115 	 */
116 	void *(*alloc)(void *cookie, size_t size, gfp_t gfp);
117 
118 	/**
119 	 * @free: Custom page de-allocator.
120 	 *
121 	 * Optional hook used to free page tables allocated with the @alloc
122 	 * hook. Must be non-NULL if @alloc is not NULL, must be NULL
123 	 * otherwise.
124 	 */
125 	void (*free)(void *cookie, void *pages, size_t size);
126 
127 	/* Low-level data specific to the table format */
128 	union {
129 		struct {
130 			u64	ttbr;
131 			struct {
132 				u32	ips:3;
133 				u32	tg:2;
134 				u32	sh:2;
135 				u32	orgn:2;
136 				u32	irgn:2;
137 				u32	tsz:6;
138 			}	tcr;
139 			u64	mair;
140 		} arm_lpae_s1_cfg;
141 
142 		struct {
143 			u64	vttbr;
144 			struct {
145 				u32	ps:3;
146 				u32	tg:2;
147 				u32	sh:2;
148 				u32	orgn:2;
149 				u32	irgn:2;
150 				u32	sl:2;
151 				u32	tsz:6;
152 			}	vtcr;
153 		} arm_lpae_s2_cfg;
154 
155 		struct {
156 			u32	ttbr;
157 			u32	tcr;
158 			u32	nmrr;
159 			u32	prrr;
160 		} arm_v7s_cfg;
161 
162 		struct {
163 			u64	transtab;
164 			u64	memattr;
165 		} arm_mali_lpae_cfg;
166 
167 		struct {
168 			u64 ttbr[4];
169 			u32 n_ttbrs;
170 		} apple_dart_cfg;
171 	};
172 };
173 
174 /**
175  * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
176  *
177  * @map_pages:    Map a physically contiguous range of pages of the same size.
178  * @unmap_pages:  Unmap a range of virtually contiguous pages of the same size.
179  * @iova_to_phys: Translate iova to physical address.
180  *
181  * These functions map directly onto the iommu_ops member functions with
182  * the same names.
183  */
184 struct io_pgtable_ops {
185 	int (*map_pages)(struct io_pgtable_ops *ops, unsigned long iova,
186 			 phys_addr_t paddr, size_t pgsize, size_t pgcount,
187 			 int prot, gfp_t gfp, size_t *mapped);
188 	size_t (*unmap_pages)(struct io_pgtable_ops *ops, unsigned long iova,
189 			      size_t pgsize, size_t pgcount,
190 			      struct iommu_iotlb_gather *gather);
191 	phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
192 				    unsigned long iova);
193 	int (*read_and_clear_dirty)(struct io_pgtable_ops *ops,
194 				    unsigned long iova, size_t size,
195 				    unsigned long flags,
196 				    struct iommu_dirty_bitmap *dirty);
197 };
198 
199 /**
200  * alloc_io_pgtable_ops() - Allocate a page table allocator for use by an IOMMU.
201  *
202  * @fmt:    The page table format.
203  * @cfg:    The page table configuration. This will be modified to represent
204  *          the configuration actually provided by the allocator (e.g. the
205  *          pgsize_bitmap may be restricted).
206  * @cookie: An opaque token provided by the IOMMU driver and passed back to
207  *          the callback routines in cfg->tlb.
208  */
209 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
210 					    struct io_pgtable_cfg *cfg,
211 					    void *cookie);
212 
213 /**
214  * free_io_pgtable_ops() - Free an io_pgtable_ops structure. The caller
215  *                         *must* ensure that the page table is no longer
216  *                         live, but the TLB can be dirty.
217  *
218  * @ops: The ops returned from alloc_io_pgtable_ops.
219  */
220 void free_io_pgtable_ops(struct io_pgtable_ops *ops);
221 
222 
223 /*
224  * Internal structures for page table allocator implementations.
225  */
226 
227 /**
228  * struct io_pgtable - Internal structure describing a set of page tables.
229  *
230  * @fmt:    The page table format.
231  * @cookie: An opaque token provided by the IOMMU driver and passed back to
232  *          any callback routines.
233  * @cfg:    A copy of the page table configuration.
234  * @ops:    The page table operations in use for this set of page tables.
235  */
236 struct io_pgtable {
237 	enum io_pgtable_fmt	fmt;
238 	void			*cookie;
239 	struct io_pgtable_cfg	cfg;
240 	struct io_pgtable_ops	ops;
241 };
242 
243 #define io_pgtable_ops_to_pgtable(x) container_of((x), struct io_pgtable, ops)
244 
245 static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
246 {
247 	if (iop->cfg.tlb && iop->cfg.tlb->tlb_flush_all)
248 		iop->cfg.tlb->tlb_flush_all(iop->cookie);
249 }
250 
251 static inline void
252 io_pgtable_tlb_flush_walk(struct io_pgtable *iop, unsigned long iova,
253 			  size_t size, size_t granule)
254 {
255 	if (iop->cfg.tlb && iop->cfg.tlb->tlb_flush_walk)
256 		iop->cfg.tlb->tlb_flush_walk(iova, size, granule, iop->cookie);
257 }
258 
259 static inline void
260 io_pgtable_tlb_add_page(struct io_pgtable *iop,
261 			struct iommu_iotlb_gather * gather, unsigned long iova,
262 			size_t granule)
263 {
264 	if (iop->cfg.tlb && iop->cfg.tlb->tlb_add_page)
265 		iop->cfg.tlb->tlb_add_page(gather, iova, granule, iop->cookie);
266 }
267 
268 /**
269  * enum io_pgtable_caps - IO page table backend capabilities.
270  */
271 enum io_pgtable_caps {
272 	/** @IO_PGTABLE_CAP_CUSTOM_ALLOCATOR: Backend accepts custom page table allocators. */
273 	IO_PGTABLE_CAP_CUSTOM_ALLOCATOR = BIT(0),
274 };
275 
276 /**
277  * struct io_pgtable_init_fns - Alloc/free a set of page tables for a
278  *                              particular format.
279  *
280  * @alloc: Allocate a set of page tables described by cfg.
281  * @free:  Free the page tables associated with iop.
282  * @caps:  Combination of @io_pgtable_caps flags encoding the backend capabilities.
283  */
284 struct io_pgtable_init_fns {
285 	struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
286 	void (*free)(struct io_pgtable *iop);
287 	u32 caps;
288 };
289 
290 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
291 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
292 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
293 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
294 extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
295 extern struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns;
296 extern struct io_pgtable_init_fns io_pgtable_amd_iommu_v1_init_fns;
297 extern struct io_pgtable_init_fns io_pgtable_amd_iommu_v2_init_fns;
298 extern struct io_pgtable_init_fns io_pgtable_apple_dart_init_fns;
299 
300 #endif /* __IO_PGTABLE_H */
301