xref: /linux/include/linux/io-pgtable.h (revision 71e2f4dd5a65bd8dbca0b77661e75eea471168f8)
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 	IO_PGTABLE_NUM_FMTS,
19 };
20 
21 /**
22  * struct iommu_flush_ops - IOMMU callbacks for TLB and page table management.
23  *
24  * @tlb_flush_all:  Synchronously invalidate the entire TLB context.
25  * @tlb_flush_walk: Synchronously invalidate all intermediate TLB state
26  *                  (sometimes referred to as the "walk cache") for a virtual
27  *                  address range.
28  * @tlb_flush_leaf: Synchronously invalidate all leaf TLB state for a virtual
29  *                  address range.
30  * @tlb_add_page:   Optional callback to queue up leaf TLB invalidation for a
31  *                  single page.  IOMMUs that cannot batch TLB invalidation
32  *                  operations efficiently will typically issue them here, but
33  *                  others may decide to update the iommu_iotlb_gather structure
34  *                  and defer the invalidation until iommu_tlb_sync() instead.
35  *
36  * Note that these can all be called in atomic context and must therefore
37  * not block.
38  */
39 struct iommu_flush_ops {
40 	void (*tlb_flush_all)(void *cookie);
41 	void (*tlb_flush_walk)(unsigned long iova, size_t size, size_t granule,
42 			       void *cookie);
43 	void (*tlb_flush_leaf)(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_TLBI_ON_MAP: If the format forbids caching invalid
76 	 *	(unmapped) entries but the hardware might do so anyway, perform
77 	 *	TLB maintenance when mapping as well as when unmapping.
78 	 *
79 	 * IO_PGTABLE_QUIRK_ARM_MTK_EXT: (ARM v7s format) MediaTek IOMMUs extend
80 	 *	to support up to 34 bits PA where the bit32 and bit33 are
81 	 *	encoded in the bit9 and bit4 of the PTE respectively.
82 	 *
83 	 * IO_PGTABLE_QUIRK_NON_STRICT: Skip issuing synchronous leaf TLBIs
84 	 *	on unmap, for DMA domains using the flush queue mechanism for
85 	 *	delayed invalidation.
86 	 */
87 	#define IO_PGTABLE_QUIRK_ARM_NS		BIT(0)
88 	#define IO_PGTABLE_QUIRK_NO_PERMS	BIT(1)
89 	#define IO_PGTABLE_QUIRK_TLBI_ON_MAP	BIT(2)
90 	#define IO_PGTABLE_QUIRK_ARM_MTK_EXT	BIT(3)
91 	#define IO_PGTABLE_QUIRK_NON_STRICT	BIT(4)
92 	unsigned long			quirks;
93 	unsigned long			pgsize_bitmap;
94 	unsigned int			ias;
95 	unsigned int			oas;
96 	bool				coherent_walk;
97 	const struct iommu_flush_ops	*tlb;
98 	struct device			*iommu_dev;
99 
100 	/* Low-level data specific to the table format */
101 	union {
102 		struct {
103 			u64	ttbr[2];
104 			u64	tcr;
105 			u64	mair[2];
106 		} arm_lpae_s1_cfg;
107 
108 		struct {
109 			u64	vttbr;
110 			u64	vtcr;
111 		} arm_lpae_s2_cfg;
112 
113 		struct {
114 			u32	ttbr[2];
115 			u32	tcr;
116 			u32	nmrr;
117 			u32	prrr;
118 		} arm_v7s_cfg;
119 
120 		struct {
121 			u64	transtab;
122 			u64	memattr;
123 		} arm_mali_lpae_cfg;
124 	};
125 };
126 
127 /**
128  * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
129  *
130  * @map:          Map a physically contiguous memory region.
131  * @unmap:        Unmap a physically contiguous memory region.
132  * @iova_to_phys: Translate iova to physical address.
133  *
134  * These functions map directly onto the iommu_ops member functions with
135  * the same names.
136  */
137 struct io_pgtable_ops {
138 	int (*map)(struct io_pgtable_ops *ops, unsigned long iova,
139 		   phys_addr_t paddr, size_t size, int prot);
140 	size_t (*unmap)(struct io_pgtable_ops *ops, unsigned long iova,
141 			size_t size, struct iommu_iotlb_gather *gather);
142 	phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
143 				    unsigned long iova);
144 };
145 
146 /**
147  * alloc_io_pgtable_ops() - Allocate a page table allocator for use by an IOMMU.
148  *
149  * @fmt:    The page table format.
150  * @cfg:    The page table configuration. This will be modified to represent
151  *          the configuration actually provided by the allocator (e.g. the
152  *          pgsize_bitmap may be restricted).
153  * @cookie: An opaque token provided by the IOMMU driver and passed back to
154  *          the callback routines in cfg->tlb.
155  */
156 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
157 					    struct io_pgtable_cfg *cfg,
158 					    void *cookie);
159 
160 /**
161  * free_io_pgtable_ops() - Free an io_pgtable_ops structure. The caller
162  *                         *must* ensure that the page table is no longer
163  *                         live, but the TLB can be dirty.
164  *
165  * @ops: The ops returned from alloc_io_pgtable_ops.
166  */
167 void free_io_pgtable_ops(struct io_pgtable_ops *ops);
168 
169 
170 /*
171  * Internal structures for page table allocator implementations.
172  */
173 
174 /**
175  * struct io_pgtable - Internal structure describing a set of page tables.
176  *
177  * @fmt:    The page table format.
178  * @cookie: An opaque token provided by the IOMMU driver and passed back to
179  *          any callback routines.
180  * @cfg:    A copy of the page table configuration.
181  * @ops:    The page table operations in use for this set of page tables.
182  */
183 struct io_pgtable {
184 	enum io_pgtable_fmt	fmt;
185 	void			*cookie;
186 	struct io_pgtable_cfg	cfg;
187 	struct io_pgtable_ops	ops;
188 };
189 
190 #define io_pgtable_ops_to_pgtable(x) container_of((x), struct io_pgtable, ops)
191 
192 static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
193 {
194 	iop->cfg.tlb->tlb_flush_all(iop->cookie);
195 }
196 
197 static inline void
198 io_pgtable_tlb_flush_walk(struct io_pgtable *iop, unsigned long iova,
199 			  size_t size, size_t granule)
200 {
201 	iop->cfg.tlb->tlb_flush_walk(iova, size, granule, iop->cookie);
202 }
203 
204 static inline void
205 io_pgtable_tlb_flush_leaf(struct io_pgtable *iop, unsigned long iova,
206 			  size_t size, size_t granule)
207 {
208 	iop->cfg.tlb->tlb_flush_leaf(iova, size, granule, iop->cookie);
209 }
210 
211 static inline void
212 io_pgtable_tlb_add_page(struct io_pgtable *iop,
213 			struct iommu_iotlb_gather * gather, unsigned long iova,
214 			size_t granule)
215 {
216 	if (iop->cfg.tlb->tlb_add_page)
217 		iop->cfg.tlb->tlb_add_page(gather, iova, granule, iop->cookie);
218 }
219 
220 /**
221  * struct io_pgtable_init_fns - Alloc/free a set of page tables for a
222  *                              particular format.
223  *
224  * @alloc: Allocate a set of page tables described by cfg.
225  * @free:  Free the page tables associated with iop.
226  */
227 struct io_pgtable_init_fns {
228 	struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
229 	void (*free)(struct io_pgtable *iop);
230 };
231 
232 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
233 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
234 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
235 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
236 extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
237 extern struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns;
238 
239 #endif /* __IO_PGTABLE_H */
240