xref: /openbmc/linux/include/linux/io-pgtable.h (revision 8d2c749e)
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_add_page:   Optional callback to queue up leaf TLB invalidation for a
29  *                  single page.  IOMMUs that cannot batch TLB invalidation
30  *                  operations efficiently will typically issue them here, but
31  *                  others may decide to update the iommu_iotlb_gather structure
32  *                  and defer the invalidation until iommu_iotlb_sync() instead.
33  *
34  * Note that these can all be called in atomic context and must therefore
35  * not block.
36  */
37 struct iommu_flush_ops {
38 	void (*tlb_flush_all)(void *cookie);
39 	void (*tlb_flush_walk)(unsigned long iova, size_t size, size_t granule,
40 			       void *cookie);
41 	void (*tlb_add_page)(struct iommu_iotlb_gather *gather,
42 			     unsigned long iova, size_t granule, void *cookie);
43 };
44 
45 /**
46  * struct io_pgtable_cfg - Configuration data for a set of page tables.
47  *
48  * @quirks:        A bitmap of hardware quirks that require some special
49  *                 action by the low-level page table allocator.
50  * @pgsize_bitmap: A bitmap of page sizes supported by this set of page
51  *                 tables.
52  * @ias:           Input address (iova) size, in bits.
53  * @oas:           Output address (paddr) size, in bits.
54  * @coherent_walk  A flag to indicate whether or not page table walks made
55  *                 by the IOMMU are coherent with the CPU caches.
56  * @tlb:           TLB management callbacks for this set of tables.
57  * @iommu_dev:     The device representing the DMA configuration for the
58  *                 page table walker.
59  */
60 struct io_pgtable_cfg {
61 	/*
62 	 * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
63 	 *	stage 1 PTEs, for hardware which insists on validating them
64 	 *	even in	non-secure state where they should normally be ignored.
65 	 *
66 	 * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
67 	 *	IOMMU_NOEXEC flags and map everything with full access, for
68 	 *	hardware which does not implement the permissions of a given
69 	 *	format, and/or requires some format-specific default value.
70 	 *
71 	 * IO_PGTABLE_QUIRK_ARM_MTK_EXT: (ARM v7s format) MediaTek IOMMUs extend
72 	 *	to support up to 35 bits PA where the bit32, bit33 and bit34 are
73 	 *	encoded in the bit9, bit4 and bit5 of the PTE respectively.
74 	 *
75 	 * IO_PGTABLE_QUIRK_NON_STRICT: Skip issuing synchronous leaf TLBIs
76 	 *	on unmap, for DMA domains using the flush queue mechanism for
77 	 *	delayed invalidation.
78 	 *
79 	 * IO_PGTABLE_QUIRK_ARM_TTBR1: (ARM LPAE format) Configure the table
80 	 *	for use in the upper half of a split address space.
81 	 *
82 	 * IO_PGTABLE_QUIRK_ARM_OUTER_WBWA: Override the outer-cacheability
83 	 *	attributes set in the TCR for a non-coherent page-table walker.
84 	 */
85 	#define IO_PGTABLE_QUIRK_ARM_NS		BIT(0)
86 	#define IO_PGTABLE_QUIRK_NO_PERMS	BIT(1)
87 	#define IO_PGTABLE_QUIRK_ARM_MTK_EXT	BIT(3)
88 	#define IO_PGTABLE_QUIRK_NON_STRICT	BIT(4)
89 	#define IO_PGTABLE_QUIRK_ARM_TTBR1	BIT(5)
90 	#define IO_PGTABLE_QUIRK_ARM_OUTER_WBWA	BIT(6)
91 	unsigned long			quirks;
92 	unsigned long			pgsize_bitmap;
93 	unsigned int			ias;
94 	unsigned int			oas;
95 	bool				coherent_walk;
96 	const struct iommu_flush_ops	*tlb;
97 	struct device			*iommu_dev;
98 
99 	/* Low-level data specific to the table format */
100 	union {
101 		struct {
102 			u64	ttbr;
103 			struct {
104 				u32	ips:3;
105 				u32	tg:2;
106 				u32	sh:2;
107 				u32	orgn:2;
108 				u32	irgn:2;
109 				u32	tsz:6;
110 			}	tcr;
111 			u64	mair;
112 		} arm_lpae_s1_cfg;
113 
114 		struct {
115 			u64	vttbr;
116 			struct {
117 				u32	ps:3;
118 				u32	tg:2;
119 				u32	sh:2;
120 				u32	orgn:2;
121 				u32	irgn:2;
122 				u32	sl:2;
123 				u32	tsz:6;
124 			}	vtcr;
125 		} arm_lpae_s2_cfg;
126 
127 		struct {
128 			u32	ttbr;
129 			u32	tcr;
130 			u32	nmrr;
131 			u32	prrr;
132 		} arm_v7s_cfg;
133 
134 		struct {
135 			u64	transtab;
136 			u64	memattr;
137 		} arm_mali_lpae_cfg;
138 	};
139 };
140 
141 /**
142  * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
143  *
144  * @map:          Map a physically contiguous memory region.
145  * @unmap:        Unmap a physically contiguous memory region.
146  * @iova_to_phys: Translate iova to physical address.
147  *
148  * These functions map directly onto the iommu_ops member functions with
149  * the same names.
150  */
151 struct io_pgtable_ops {
152 	int (*map)(struct io_pgtable_ops *ops, unsigned long iova,
153 		   phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
154 	size_t (*unmap)(struct io_pgtable_ops *ops, unsigned long iova,
155 			size_t size, struct iommu_iotlb_gather *gather);
156 	phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
157 				    unsigned long iova);
158 };
159 
160 /**
161  * alloc_io_pgtable_ops() - Allocate a page table allocator for use by an IOMMU.
162  *
163  * @fmt:    The page table format.
164  * @cfg:    The page table configuration. This will be modified to represent
165  *          the configuration actually provided by the allocator (e.g. the
166  *          pgsize_bitmap may be restricted).
167  * @cookie: An opaque token provided by the IOMMU driver and passed back to
168  *          the callback routines in cfg->tlb.
169  */
170 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
171 					    struct io_pgtable_cfg *cfg,
172 					    void *cookie);
173 
174 /**
175  * free_io_pgtable_ops() - Free an io_pgtable_ops structure. The caller
176  *                         *must* ensure that the page table is no longer
177  *                         live, but the TLB can be dirty.
178  *
179  * @ops: The ops returned from alloc_io_pgtable_ops.
180  */
181 void free_io_pgtable_ops(struct io_pgtable_ops *ops);
182 
183 
184 /*
185  * Internal structures for page table allocator implementations.
186  */
187 
188 /**
189  * struct io_pgtable - Internal structure describing a set of page tables.
190  *
191  * @fmt:    The page table format.
192  * @cookie: An opaque token provided by the IOMMU driver and passed back to
193  *          any callback routines.
194  * @cfg:    A copy of the page table configuration.
195  * @ops:    The page table operations in use for this set of page tables.
196  */
197 struct io_pgtable {
198 	enum io_pgtable_fmt	fmt;
199 	void			*cookie;
200 	struct io_pgtable_cfg	cfg;
201 	struct io_pgtable_ops	ops;
202 };
203 
204 #define io_pgtable_ops_to_pgtable(x) container_of((x), struct io_pgtable, ops)
205 
206 struct io_pgtable_domain_attr {
207 	unsigned long quirks;
208 };
209 
210 static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
211 {
212 	if (iop->cfg.tlb && iop->cfg.tlb->tlb_flush_all)
213 		iop->cfg.tlb->tlb_flush_all(iop->cookie);
214 }
215 
216 static inline void
217 io_pgtable_tlb_flush_walk(struct io_pgtable *iop, unsigned long iova,
218 			  size_t size, size_t granule)
219 {
220 	if (iop->cfg.tlb && iop->cfg.tlb->tlb_flush_walk)
221 		iop->cfg.tlb->tlb_flush_walk(iova, size, granule, iop->cookie);
222 }
223 
224 static inline void
225 io_pgtable_tlb_add_page(struct io_pgtable *iop,
226 			struct iommu_iotlb_gather * gather, unsigned long iova,
227 			size_t granule)
228 {
229 	if (iop->cfg.tlb && iop->cfg.tlb->tlb_add_page)
230 		iop->cfg.tlb->tlb_add_page(gather, iova, granule, iop->cookie);
231 }
232 
233 /**
234  * struct io_pgtable_init_fns - Alloc/free a set of page tables for a
235  *                              particular format.
236  *
237  * @alloc: Allocate a set of page tables described by cfg.
238  * @free:  Free the page tables associated with iop.
239  */
240 struct io_pgtable_init_fns {
241 	struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
242 	void (*free)(struct io_pgtable *iop);
243 };
244 
245 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
246 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
247 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
248 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
249 extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
250 extern struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns;
251 
252 #endif /* __IO_PGTABLE_H */
253