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1 /*
2  * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #ifndef __XLAT_TABLES_V2_H__
8 #define __XLAT_TABLES_V2_H__
9 
10 #include <xlat_tables_defs.h>
11 
12 #ifndef __ASSEMBLY__
13 #include <stddef.h>
14 #include <stdint.h>
15 #include <xlat_mmu_helpers.h>
16 #include <xlat_tables_v2_helpers.h>
17 
18 /*
19  * Default granularity size for an mmap_region_t.
20  * Useful when no specific granularity is required.
21  *
22  * By default, choose the biggest possible block size allowed by the
23  * architectural state and granule size in order to minimize the number of page
24  * tables required for the mapping.
25  */
26 #define REGION_DEFAULT_GRANULARITY	XLAT_BLOCK_SIZE(MIN_LVL_BLOCK_DESC)
27 
28 /* Helper macro to define an mmap_region_t. */
29 #define MAP_REGION(_pa, _va, _sz, _attr)	\
30 	_MAP_REGION_FULL_SPEC(_pa, _va, _sz, _attr, REGION_DEFAULT_GRANULARITY)
31 
32 /* Helper macro to define an mmap_region_t with an identity mapping. */
33 #define MAP_REGION_FLAT(_adr, _sz, _attr)			\
34 	MAP_REGION(_adr, _adr, _sz, _attr)
35 
36 /*
37  * Helper macro to define an mmap_region_t to map with the desired granularity
38  * of translation tables.
39  *
40  * The granularity value passed to this macro must be a valid block or page
41  * size. When using a 4KB translation granule, this might be 4KB, 2MB or 1GB.
42  * Passing REGION_DEFAULT_GRANULARITY is also allowed and means that the library
43  * is free to choose the granularity for this region. In this case, it is
44  * equivalent to the MAP_REGION() macro.
45  */
46 #define MAP_REGION2(_pa, _va, _sz, _attr, _gr)			\
47 	_MAP_REGION_FULL_SPEC(_pa, _va, _sz, _attr, _gr)
48 
49 /*
50  * Shifts and masks to access fields of an mmap_attr_t
51  */
52 #define MT_TYPE_MASK		U(0x7)
53 #define MT_TYPE(_attr)		((_attr) & MT_TYPE_MASK)
54 /* Access permissions (RO/RW) */
55 #define MT_PERM_SHIFT		U(3)
56 /* Security state (SECURE/NS) */
57 #define MT_SEC_SHIFT		U(4)
58 /* Access permissions for instruction execution (EXECUTE/EXECUTE_NEVER) */
59 #define MT_EXECUTE_SHIFT	U(5)
60 /*
61  * In the EL1&0 translation regime, mark the region as User (EL0) or
62  * Privileged (EL1). In the EL3 translation regime this has no effect.
63  */
64 #define MT_USER_SHIFT		U(6)
65 /* All other bits are reserved */
66 
67 /*
68  * Memory mapping attributes
69  */
70 typedef enum  {
71 	/*
72 	 * Memory types supported.
73 	 * These are organised so that, going down the list, the memory types
74 	 * are getting weaker; conversely going up the list the memory types are
75 	 * getting stronger.
76 	 */
77 	MT_DEVICE,
78 	MT_NON_CACHEABLE,
79 	MT_MEMORY,
80 	/* Values up to 7 are reserved to add new memory types in the future */
81 
82 	MT_RO		= U(0) << MT_PERM_SHIFT,
83 	MT_RW		= U(1) << MT_PERM_SHIFT,
84 
85 	MT_SECURE	= U(0) << MT_SEC_SHIFT,
86 	MT_NS		= U(1) << MT_SEC_SHIFT,
87 
88 	/*
89 	 * Access permissions for instruction execution are only relevant for
90 	 * normal read-only memory, i.e. MT_MEMORY | MT_RO. They are ignored
91 	 * (and potentially overridden) otherwise:
92 	 *  - Device memory is always marked as execute-never.
93 	 *  - Read-write normal memory is always marked as execute-never.
94 	 */
95 	MT_EXECUTE		= U(0) << MT_EXECUTE_SHIFT,
96 	MT_EXECUTE_NEVER	= U(1) << MT_EXECUTE_SHIFT,
97 
98 	/*
99 	 * When mapping a region at EL0 or EL1, this attribute will be used to
100 	 * determine if a User mapping (EL0) will be created or a Privileged
101 	 * mapping (EL1).
102 	 */
103 	MT_USER				= U(1) << MT_USER_SHIFT,
104 	MT_PRIVILEGED			= U(0) << MT_USER_SHIFT,
105 } mmap_attr_t;
106 
107 /* Compound attributes for most common usages */
108 #define MT_CODE		(MT_MEMORY | MT_RO | MT_EXECUTE)
109 #define MT_RO_DATA	(MT_MEMORY | MT_RO | MT_EXECUTE_NEVER)
110 #define MT_RW_DATA	(MT_MEMORY | MT_RW | MT_EXECUTE_NEVER)
111 
112 /*
113  * Structure for specifying a single region of memory.
114  */
115 typedef struct mmap_region {
116 	unsigned long long	base_pa;
117 	uintptr_t		base_va;
118 	size_t			size;
119 	mmap_attr_t		attr;
120 	/* Desired granularity. See the MAP_REGION2() macro for more details. */
121 	size_t			granularity;
122 } mmap_region_t;
123 
124 /*
125  * Translation regimes supported by this library.
126  */
127 typedef enum xlat_regime {
128 	EL1_EL0_REGIME,
129 	EL3_REGIME,
130 } xlat_regime_t;
131 
132 /*
133  * Declare the translation context type.
134  * Its definition is private.
135  */
136 typedef struct xlat_ctx xlat_ctx_t;
137 
138 /*
139  * Statically allocate a translation context and associated structures. Also
140  * initialize them.
141  *
142  * _ctx_name:
143  *   Prefix for the translation context variable.
144  *   E.g. If _ctx_name is 'foo', the variable will be called 'foo_xlat_ctx'.
145  *   Useful to distinguish multiple contexts from one another.
146  *
147  * _mmap_count:
148  *   Number of mmap_region_t to allocate.
149  *   Would typically be MAX_MMAP_REGIONS for the translation context describing
150  *   the BL image currently executing.
151  *
152  * _xlat_tables_count:
153  *   Number of sub-translation tables to allocate.
154  *   Would typically be MAX_XLAT_TABLES for the translation context describing
155  *   the BL image currently executing.
156  *   Note that this is only for sub-tables ; at the initial lookup level, there
157  *   is always a single table.
158  *
159  * _virt_addr_space_size, _phy_addr_space_size:
160  *   Size (in bytes) of the virtual (resp. physical) address space.
161  *   Would typically be PLAT_VIRT_ADDR_SPACE_SIZE
162  *   (resp. PLAT_PHY_ADDR_SPACE_SIZE) for the translation context describing the
163  *   BL image currently executing.
164  */
165 #define REGISTER_XLAT_CONTEXT(_ctx_name, _mmap_count, _xlat_tables_count,	\
166 			_virt_addr_space_size, _phy_addr_space_size)		\
167 	_REGISTER_XLAT_CONTEXT_FULL_SPEC(_ctx_name, _mmap_count,	\
168 					 _xlat_tables_count,		\
169 					 _virt_addr_space_size,		\
170 					 _phy_addr_space_size,		\
171 					 IMAGE_XLAT_DEFAULT_REGIME)
172 
173 /*
174  * Same as REGISTER_XLAT_CONTEXT plus the additional parameter _xlat_regime to
175  * specify the translation regime managed by this xlat_ctx_t instance. The
176  * values are the one from xlat_regime_t enumeration.
177  */
178 #define REGISTER_XLAT_CONTEXT2(_ctx_name, _mmap_count, _xlat_tables_count,	\
179 			_virt_addr_space_size, _phy_addr_space_size,		\
180 			_xlat_regime)					\
181 	_REGISTER_XLAT_CONTEXT_FULL_SPEC(_ctx_name, _mmap_count,	\
182 					 _xlat_tables_count,		\
183 					 _virt_addr_space_size,		\
184 					 _phy_addr_space_size,		\
185 					 _xlat_regime)
186 
187 /******************************************************************************
188  * Generic translation table APIs.
189  * Each API comes in 2 variants:
190  * - one that acts on the current translation context for this BL image
191  * - another that acts on the given translation context instead. This variant
192  *   is named after the 1st version, with an additional '_ctx' suffix.
193  *****************************************************************************/
194 
195 /*
196  * Initialize translation tables from the current list of mmap regions. Calling
197  * this function marks the transition point after which static regions can no
198  * longer be added.
199  */
200 void init_xlat_tables(void);
201 void init_xlat_tables_ctx(xlat_ctx_t *ctx);
202 
203 /*
204  * Add a static region with defined base PA and base VA. This function can only
205  * be used before initializing the translation tables. The region cannot be
206  * removed afterwards.
207  */
208 void mmap_add_region(unsigned long long base_pa, uintptr_t base_va,
209 				size_t size, mmap_attr_t attr);
210 void mmap_add_region_ctx(xlat_ctx_t *ctx, const mmap_region_t *mm);
211 
212 /*
213  * Add an array of static regions with defined base PA and base VA. This
214  * function can only be used before initializing the translation tables. The
215  * regions cannot be removed afterwards.
216  */
217 void mmap_add(const mmap_region_t *mm);
218 void mmap_add_ctx(xlat_ctx_t *ctx, const mmap_region_t *mm);
219 
220 
221 #if PLAT_XLAT_TABLES_DYNAMIC
222 /*
223  * Add a dynamic region with defined base PA and base VA. This type of region
224  * can be added and removed even after the translation tables are initialized.
225  *
226  * Returns:
227  *        0: Success.
228  *   EINVAL: Invalid values were used as arguments.
229  *   ERANGE: Memory limits were surpassed.
230  *   ENOMEM: Not enough space in the mmap array or not enough free xlat tables.
231  *    EPERM: It overlaps another region in an invalid way.
232  */
233 int mmap_add_dynamic_region(unsigned long long base_pa, uintptr_t base_va,
234 				size_t size, mmap_attr_t attr);
235 int mmap_add_dynamic_region_ctx(xlat_ctx_t *ctx, mmap_region_t *mm);
236 
237 /*
238  * Remove a region with the specified base VA and size. Only dynamic regions can
239  * be removed, and they can be removed even if the translation tables are
240  * initialized.
241  *
242  * Returns:
243  *        0: Success.
244  *   EINVAL: The specified region wasn't found.
245  *    EPERM: Trying to remove a static region.
246  */
247 int mmap_remove_dynamic_region(uintptr_t base_va, size_t size);
248 int mmap_remove_dynamic_region_ctx(xlat_ctx_t *ctx,
249 				uintptr_t base_va,
250 				size_t size);
251 
252 #endif /* PLAT_XLAT_TABLES_DYNAMIC */
253 
254 /*
255  * Change the memory attributes of the memory region starting from a given
256  * virtual address in a set of translation tables.
257  *
258  * This function can only be used after the translation tables have been
259  * initialized.
260  *
261  * The base address of the memory region must be aligned on a page boundary.
262  * The size of this memory region must be a multiple of a page size.
263  * The memory region must be already mapped by the given translation tables
264  * and it must be mapped at the granularity of a page.
265  *
266  * Return 0 on success, a negative value on error.
267  *
268  * In case of error, the memory attributes remain unchanged and this function
269  * has no effect.
270  *
271  * ctx
272  *   Translation context to work on.
273  * base_va:
274  *   Virtual address of the 1st page to change the attributes of.
275  * size:
276  *   Size in bytes of the memory region.
277  * attr:
278  *   New attributes of the page tables. The attributes that can be changed are
279  *   data access (MT_RO/MT_RW), instruction access (MT_EXECUTE_NEVER/MT_EXECUTE)
280  *   and user/privileged access (MT_USER/MT_PRIVILEGED) in the case of contexts
281  *   that are used in the EL1&0 translation regime. Also, note that this
282  *   function doesn't allow to remap a region as RW and executable, or to remap
283  *   device memory as executable.
284  *
285  * NOTE: The caller of this function must be able to write to the translation
286  * tables, i.e. the memory where they are stored must be mapped with read-write
287  * access permissions. This function assumes it is the case. If this is not
288  * the case then this function might trigger a data abort exception.
289  *
290  * NOTE2: The caller is responsible for making sure that the targeted
291  * translation tables are not modified by any other code while this function is
292  * executing.
293  */
294 int change_mem_attributes(xlat_ctx_t *ctx, uintptr_t base_va, size_t size,
295 			mmap_attr_t attr);
296 
297 /*
298  * Query the memory attributes of a memory page in a set of translation tables.
299  *
300  * Return 0 on success, a negative error code on error.
301  * On success, the attributes are stored into *attributes.
302  *
303  * ctx
304  *   Translation context to work on.
305  * base_va
306  *   Virtual address of the page to get the attributes of.
307  *   There are no alignment restrictions on this address. The attributes of the
308  *   memory page it lies within are returned.
309  * attributes
310  *   Output parameter where to store the attributes of the targeted memory page.
311  */
312 int get_mem_attributes(const xlat_ctx_t *ctx, uintptr_t base_va,
313 		mmap_attr_t *attributes);
314 
315 #endif /*__ASSEMBLY__*/
316 #endif /* __XLAT_TABLES_V2_H__ */
317