xref: /linux/include/linux/io-pgtable.h (revision 6093a688a07da07808f0122f9aa2a3eed250d853)
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 	 * IO_PGTABLE_QUIRK_ARM_HD: Enables dirty tracking in stage 1 pagetable.
90 	 * IO_PGTABLE_QUIRK_ARM_S2FWB: Use the FWB format for the MemAttrs bits
91 	 *
92 	 * IO_PGTABLE_QUIRK_NO_WARN: Do not WARN_ON() on conflicting
93 	 *	mappings, but silently return -EEXISTS.  Normally an attempt
94 	 *	to map over an existing mapping would indicate some sort of
95 	 *	kernel bug, which would justify the WARN_ON().  But for GPU
96 	 *	drivers, this could be under control of userspace.  Which
97 	 *	deserves an error return, but not to spam dmesg.
98 	 */
99 	#define IO_PGTABLE_QUIRK_ARM_NS			BIT(0)
100 	#define IO_PGTABLE_QUIRK_NO_PERMS		BIT(1)
101 	#define IO_PGTABLE_QUIRK_ARM_MTK_EXT		BIT(3)
102 	#define IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT	BIT(4)
103 	#define IO_PGTABLE_QUIRK_ARM_TTBR1		BIT(5)
104 	#define IO_PGTABLE_QUIRK_ARM_OUTER_WBWA		BIT(6)
105 	#define IO_PGTABLE_QUIRK_ARM_HD			BIT(7)
106 	#define IO_PGTABLE_QUIRK_ARM_S2FWB		BIT(8)
107 	#define IO_PGTABLE_QUIRK_NO_WARN		BIT(9)
108 	unsigned long			quirks;
109 	unsigned long			pgsize_bitmap;
110 	unsigned int			ias;
111 	unsigned int			oas;
112 	bool				coherent_walk;
113 	const struct iommu_flush_ops	*tlb;
114 	struct device			*iommu_dev;
115 
116 	/**
117 	 * @alloc: Custom page allocator.
118 	 *
119 	 * Optional hook used to allocate page tables. If this function is NULL,
120 	 * @free must be NULL too.
121 	 *
122 	 * Memory returned should be zeroed and suitable for dma_map_single() and
123 	 * virt_to_phys().
124 	 *
125 	 * Not all formats support custom page allocators. Before considering
126 	 * passing a non-NULL value, make sure the chosen page format supports
127 	 * this feature.
128 	 */
129 	void *(*alloc)(void *cookie, size_t size, gfp_t gfp);
130 
131 	/**
132 	 * @free: Custom page de-allocator.
133 	 *
134 	 * Optional hook used to free page tables allocated with the @alloc
135 	 * hook. Must be non-NULL if @alloc is not NULL, must be NULL
136 	 * otherwise.
137 	 */
138 	void (*free)(void *cookie, void *pages, size_t size);
139 
140 	/* Low-level data specific to the table format */
141 	union {
142 		struct {
143 			u64	ttbr;
144 			struct {
145 				u32	ips:3;
146 				u32	tg:2;
147 				u32	sh:2;
148 				u32	orgn:2;
149 				u32	irgn:2;
150 				u32	tsz:6;
151 			}	tcr;
152 			u64	mair;
153 		} arm_lpae_s1_cfg;
154 
155 		struct {
156 			u64	vttbr;
157 			struct {
158 				u32	ps:3;
159 				u32	tg:2;
160 				u32	sh:2;
161 				u32	orgn:2;
162 				u32	irgn:2;
163 				u32	sl:2;
164 				u32	tsz:6;
165 			}	vtcr;
166 		} arm_lpae_s2_cfg;
167 
168 		struct {
169 			u32	ttbr;
170 			u32	tcr;
171 			u32	nmrr;
172 			u32	prrr;
173 		} arm_v7s_cfg;
174 
175 		struct {
176 			u64	transtab;
177 			u64	memattr;
178 		} arm_mali_lpae_cfg;
179 
180 		struct {
181 			u64 ttbr[4];
182 			u32 n_ttbrs;
183 			u32 n_levels;
184 		} apple_dart_cfg;
185 
186 		struct {
187 			int nid;
188 		} amd;
189 	};
190 };
191 
192 /**
193  * struct arm_lpae_io_pgtable_walk_data - information from a pgtable walk
194  *
195  * @ptes:     The recorded PTE values from the walk
196  */
197 struct arm_lpae_io_pgtable_walk_data {
198 	u64 ptes[4];
199 };
200 
201 /**
202  * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
203  *
204  * @map_pages:    Map a physically contiguous range of pages of the same size.
205  * @unmap_pages:  Unmap a range of virtually contiguous pages of the same size.
206  * @iova_to_phys: Translate iova to physical address.
207  * @pgtable_walk: (optional) Perform a page table walk for a given iova.
208  *
209  * These functions map directly onto the iommu_ops member functions with
210  * the same names.
211  */
212 struct io_pgtable_ops {
213 	int (*map_pages)(struct io_pgtable_ops *ops, unsigned long iova,
214 			 phys_addr_t paddr, size_t pgsize, size_t pgcount,
215 			 int prot, gfp_t gfp, size_t *mapped);
216 	size_t (*unmap_pages)(struct io_pgtable_ops *ops, unsigned long iova,
217 			      size_t pgsize, size_t pgcount,
218 			      struct iommu_iotlb_gather *gather);
219 	phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
220 				    unsigned long iova);
221 	int (*pgtable_walk)(struct io_pgtable_ops *ops, unsigned long iova, void *wd);
222 	int (*read_and_clear_dirty)(struct io_pgtable_ops *ops,
223 				    unsigned long iova, size_t size,
224 				    unsigned long flags,
225 				    struct iommu_dirty_bitmap *dirty);
226 };
227 
228 /**
229  * alloc_io_pgtable_ops() - Allocate a page table allocator for use by an IOMMU.
230  *
231  * @fmt:    The page table format.
232  * @cfg:    The page table configuration. This will be modified to represent
233  *          the configuration actually provided by the allocator (e.g. the
234  *          pgsize_bitmap may be restricted).
235  * @cookie: An opaque token provided by the IOMMU driver and passed back to
236  *          the callback routines in cfg->tlb.
237  */
238 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
239 					    struct io_pgtable_cfg *cfg,
240 					    void *cookie);
241 
242 /**
243  * free_io_pgtable_ops() - Free an io_pgtable_ops structure. The caller
244  *                         *must* ensure that the page table is no longer
245  *                         live, but the TLB can be dirty.
246  *
247  * @ops: The ops returned from alloc_io_pgtable_ops.
248  */
249 void free_io_pgtable_ops(struct io_pgtable_ops *ops);
250 
251 
252 /*
253  * Internal structures for page table allocator implementations.
254  */
255 
256 /**
257  * struct io_pgtable - Internal structure describing a set of page tables.
258  *
259  * @fmt:    The page table format.
260  * @cookie: An opaque token provided by the IOMMU driver and passed back to
261  *          any callback routines.
262  * @cfg:    A copy of the page table configuration.
263  * @ops:    The page table operations in use for this set of page tables.
264  */
265 struct io_pgtable {
266 	enum io_pgtable_fmt	fmt;
267 	void			*cookie;
268 	struct io_pgtable_cfg	cfg;
269 	struct io_pgtable_ops	ops;
270 };
271 
272 #define io_pgtable_ops_to_pgtable(x) container_of((x), struct io_pgtable, ops)
273 
274 static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
275 {
276 	if (iop->cfg.tlb && iop->cfg.tlb->tlb_flush_all)
277 		iop->cfg.tlb->tlb_flush_all(iop->cookie);
278 }
279 
280 static inline void
281 io_pgtable_tlb_flush_walk(struct io_pgtable *iop, unsigned long iova,
282 			  size_t size, size_t granule)
283 {
284 	if (iop->cfg.tlb && iop->cfg.tlb->tlb_flush_walk)
285 		iop->cfg.tlb->tlb_flush_walk(iova, size, granule, iop->cookie);
286 }
287 
288 static inline void
289 io_pgtable_tlb_add_page(struct io_pgtable *iop,
290 			struct iommu_iotlb_gather * gather, unsigned long iova,
291 			size_t granule)
292 {
293 	if (iop->cfg.tlb && iop->cfg.tlb->tlb_add_page)
294 		iop->cfg.tlb->tlb_add_page(gather, iova, granule, iop->cookie);
295 }
296 
297 /**
298  * enum io_pgtable_caps - IO page table backend capabilities.
299  */
300 enum io_pgtable_caps {
301 	/** @IO_PGTABLE_CAP_CUSTOM_ALLOCATOR: Backend accepts custom page table allocators. */
302 	IO_PGTABLE_CAP_CUSTOM_ALLOCATOR = BIT(0),
303 };
304 
305 /**
306  * struct io_pgtable_init_fns - Alloc/free a set of page tables for a
307  *                              particular format.
308  *
309  * @alloc: Allocate a set of page tables described by cfg.
310  * @free:  Free the page tables associated with iop.
311  * @caps:  Combination of @io_pgtable_caps flags encoding the backend capabilities.
312  */
313 struct io_pgtable_init_fns {
314 	struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
315 	void (*free)(struct io_pgtable *iop);
316 	u32 caps;
317 };
318 
319 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
320 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
321 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
322 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
323 extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
324 extern struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns;
325 extern struct io_pgtable_init_fns io_pgtable_amd_iommu_v1_init_fns;
326 extern struct io_pgtable_init_fns io_pgtable_amd_iommu_v2_init_fns;
327 extern struct io_pgtable_init_fns io_pgtable_apple_dart_init_fns;
328 
329 #endif /* __IO_PGTABLE_H */
330