xref: /linux/include/linux/io-pgtable.h (revision be709d48329a500621d2a05835283150ae137b45)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __IO_PGTABLE_H
3 #define __IO_PGTABLE_H
4 #include <linux/bitops.h>
5 
6 /*
7  * Public API for use by IOMMU drivers
8  */
9 enum io_pgtable_fmt {
10 	ARM_32_LPAE_S1,
11 	ARM_32_LPAE_S2,
12 	ARM_64_LPAE_S1,
13 	ARM_64_LPAE_S2,
14 	ARM_V7S,
15 	IO_PGTABLE_NUM_FMTS,
16 };
17 
18 /**
19  * struct iommu_gather_ops - IOMMU callbacks for TLB and page table management.
20  *
21  * @tlb_flush_all: Synchronously invalidate the entire TLB context.
22  * @tlb_add_flush: Queue up a TLB invalidation for a virtual address range.
23  * @tlb_sync:      Ensure any queued TLB invalidation has taken effect, and
24  *                 any corresponding page table updates are visible to the
25  *                 IOMMU.
26  *
27  * Note that these can all be called in atomic context and must therefore
28  * not block.
29  */
30 struct iommu_gather_ops {
31 	void (*tlb_flush_all)(void *cookie);
32 	void (*tlb_add_flush)(unsigned long iova, size_t size, size_t granule,
33 			      bool leaf, void *cookie);
34 	void (*tlb_sync)(void *cookie);
35 };
36 
37 /**
38  * struct io_pgtable_cfg - Configuration data for a set of page tables.
39  *
40  * @quirks:        A bitmap of hardware quirks that require some special
41  *                 action by the low-level page table allocator.
42  * @pgsize_bitmap: A bitmap of page sizes supported by this set of page
43  *                 tables.
44  * @ias:           Input address (iova) size, in bits.
45  * @oas:           Output address (paddr) size, in bits.
46  * @tlb:           TLB management callbacks for this set of tables.
47  * @iommu_dev:     The device representing the DMA configuration for the
48  *                 page table walker.
49  */
50 struct io_pgtable_cfg {
51 	/*
52 	 * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
53 	 *	stage 1 PTEs, for hardware which insists on validating them
54 	 *	even in	non-secure state where they should normally be ignored.
55 	 *
56 	 * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
57 	 *	IOMMU_NOEXEC flags and map everything with full access, for
58 	 *	hardware which does not implement the permissions of a given
59 	 *	format, and/or requires some format-specific default value.
60 	 *
61 	 * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid
62 	 *	(unmapped) entries but the hardware might do so anyway, perform
63 	 *	TLB maintenance when mapping as well as when unmapping.
64 	 *
65 	 * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
66 	 *	PTEs, for Mediatek IOMMUs which treat it as a 33rd address bit
67 	 *	when the SoC is in "4GB mode" and they can only access the high
68 	 *	remap of DRAM (0x1_00000000 to 0x1_ffffffff).
69 	 *
70 	 * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only ever
71 	 *	be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a
72 	 *	software-emulated IOMMU), such that pagetable updates need not
73 	 *	be treated as explicit DMA data.
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 	#define IO_PGTABLE_QUIRK_ARM_NS		BIT(0)
80 	#define IO_PGTABLE_QUIRK_NO_PERMS	BIT(1)
81 	#define IO_PGTABLE_QUIRK_TLBI_ON_MAP	BIT(2)
82 	#define IO_PGTABLE_QUIRK_ARM_MTK_4GB	BIT(3)
83 	#define IO_PGTABLE_QUIRK_NO_DMA		BIT(4)
84 	#define IO_PGTABLE_QUIRK_NON_STRICT	BIT(5)
85 	unsigned long			quirks;
86 	unsigned long			pgsize_bitmap;
87 	unsigned int			ias;
88 	unsigned int			oas;
89 	const struct iommu_gather_ops	*tlb;
90 	struct device			*iommu_dev;
91 
92 	/* Low-level data specific to the table format */
93 	union {
94 		struct {
95 			u64	ttbr[2];
96 			u64	tcr;
97 			u64	mair[2];
98 		} arm_lpae_s1_cfg;
99 
100 		struct {
101 			u64	vttbr;
102 			u64	vtcr;
103 		} arm_lpae_s2_cfg;
104 
105 		struct {
106 			u32	ttbr[2];
107 			u32	tcr;
108 			u32	nmrr;
109 			u32	prrr;
110 		} arm_v7s_cfg;
111 	};
112 };
113 
114 /**
115  * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
116  *
117  * @map:          Map a physically contiguous memory region.
118  * @unmap:        Unmap a physically contiguous memory region.
119  * @iova_to_phys: Translate iova to physical address.
120  *
121  * These functions map directly onto the iommu_ops member functions with
122  * the same names.
123  */
124 struct io_pgtable_ops {
125 	int (*map)(struct io_pgtable_ops *ops, unsigned long iova,
126 		   phys_addr_t paddr, size_t size, int prot);
127 	size_t (*unmap)(struct io_pgtable_ops *ops, unsigned long iova,
128 			size_t size);
129 	phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
130 				    unsigned long iova);
131 };
132 
133 /**
134  * alloc_io_pgtable_ops() - Allocate a page table allocator for use by an IOMMU.
135  *
136  * @fmt:    The page table format.
137  * @cfg:    The page table configuration. This will be modified to represent
138  *          the configuration actually provided by the allocator (e.g. the
139  *          pgsize_bitmap may be restricted).
140  * @cookie: An opaque token provided by the IOMMU driver and passed back to
141  *          the callback routines in cfg->tlb.
142  */
143 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
144 					    struct io_pgtable_cfg *cfg,
145 					    void *cookie);
146 
147 /**
148  * free_io_pgtable_ops() - Free an io_pgtable_ops structure. The caller
149  *                         *must* ensure that the page table is no longer
150  *                         live, but the TLB can be dirty.
151  *
152  * @ops: The ops returned from alloc_io_pgtable_ops.
153  */
154 void free_io_pgtable_ops(struct io_pgtable_ops *ops);
155 
156 
157 /*
158  * Internal structures for page table allocator implementations.
159  */
160 
161 /**
162  * struct io_pgtable - Internal structure describing a set of page tables.
163  *
164  * @fmt:    The page table format.
165  * @cookie: An opaque token provided by the IOMMU driver and passed back to
166  *          any callback routines.
167  * @cfg:    A copy of the page table configuration.
168  * @ops:    The page table operations in use for this set of page tables.
169  */
170 struct io_pgtable {
171 	enum io_pgtable_fmt	fmt;
172 	void			*cookie;
173 	struct io_pgtable_cfg	cfg;
174 	struct io_pgtable_ops	ops;
175 };
176 
177 #define io_pgtable_ops_to_pgtable(x) container_of((x), struct io_pgtable, ops)
178 
179 static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
180 {
181 	iop->cfg.tlb->tlb_flush_all(iop->cookie);
182 }
183 
184 static inline void io_pgtable_tlb_add_flush(struct io_pgtable *iop,
185 		unsigned long iova, size_t size, size_t granule, bool leaf)
186 {
187 	iop->cfg.tlb->tlb_add_flush(iova, size, granule, leaf, iop->cookie);
188 }
189 
190 static inline void io_pgtable_tlb_sync(struct io_pgtable *iop)
191 {
192 	iop->cfg.tlb->tlb_sync(iop->cookie);
193 }
194 
195 /**
196  * struct io_pgtable_init_fns - Alloc/free a set of page tables for a
197  *                              particular format.
198  *
199  * @alloc: Allocate a set of page tables described by cfg.
200  * @free:  Free the page tables associated with iop.
201  */
202 struct io_pgtable_init_fns {
203 	struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
204 	void (*free)(struct io_pgtable *iop);
205 };
206 
207 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
208 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
209 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
210 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
211 extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
212 
213 #endif /* __IO_PGTABLE_H */
214