xref: /linux/arch/arm64/include/asm/memory.h (revision 9b27b117e29f63d0db3fcc474f645d6f4af6d3e4)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Based on arch/arm/include/asm/memory.h
4  *
5  * Copyright (C) 2000-2002 Russell King
6  * Copyright (C) 2012 ARM Ltd.
7  *
8  * Note: this file should not be included by non-asm/.h files
9  */
10 #ifndef __ASM_MEMORY_H
11 #define __ASM_MEMORY_H
12 
13 #include <linux/const.h>
14 #include <linux/sizes.h>
15 #include <asm/page-def.h>
16 
17 /*
18  * Size of the PCI I/O space. This must remain a power of two so that
19  * IO_SPACE_LIMIT acts as a mask for the low bits of I/O addresses.
20  */
21 #define PCI_IO_SIZE		SZ_16M
22 
23 /*
24  * VMEMMAP_SIZE - allows the whole linear region to be covered by
25  *                a struct page array
26  *
27  * If we are configured with a 52-bit kernel VA then our VMEMMAP_SIZE
28  * needs to cover the memory region from the beginning of the 52-bit
29  * PAGE_OFFSET all the way to PAGE_END for 48-bit. This allows us to
30  * keep a constant PAGE_OFFSET and "fallback" to using the higher end
31  * of the VMEMMAP where 52-bit support is not available in hardware.
32  */
33 #define VMEMMAP_SHIFT	(PAGE_SHIFT - STRUCT_PAGE_MAX_SHIFT)
34 #define VMEMMAP_SIZE	((_PAGE_END(VA_BITS_MIN) - PAGE_OFFSET) >> VMEMMAP_SHIFT)
35 
36 /*
37  * PAGE_OFFSET - the virtual address of the start of the linear map, at the
38  *               start of the TTBR1 address space.
39  * PAGE_END - the end of the linear map, where all other kernel mappings begin.
40  * KIMAGE_VADDR - the virtual address of the start of the kernel image.
41  * VA_BITS - the maximum number of bits for virtual addresses.
42  */
43 #define VA_BITS			(CONFIG_ARM64_VA_BITS)
44 #define _PAGE_OFFSET(va)	(-(UL(1) << (va)))
45 #define PAGE_OFFSET		(_PAGE_OFFSET(VA_BITS))
46 #define KIMAGE_VADDR		(MODULES_END)
47 #define MODULES_END		(MODULES_VADDR + MODULES_VSIZE)
48 #define MODULES_VADDR		(_PAGE_END(VA_BITS_MIN))
49 #define MODULES_VSIZE		(SZ_2G)
50 #define VMEMMAP_START		(-(UL(1) << (VA_BITS - VMEMMAP_SHIFT)))
51 #define VMEMMAP_END		(VMEMMAP_START + VMEMMAP_SIZE)
52 #define PCI_IO_END		(VMEMMAP_START - SZ_8M)
53 #define PCI_IO_START		(PCI_IO_END - PCI_IO_SIZE)
54 #define FIXADDR_TOP		(VMEMMAP_START - SZ_32M)
55 
56 #if VA_BITS > 48
57 #define VA_BITS_MIN		(48)
58 #else
59 #define VA_BITS_MIN		(VA_BITS)
60 #endif
61 
62 #define _PAGE_END(va)		(-(UL(1) << ((va) - 1)))
63 
64 #define KERNEL_START		_text
65 #define KERNEL_END		_end
66 
67 /*
68  * Generic and Software Tag-Based KASAN modes require 1/8th and 1/16th of the
69  * kernel virtual address space for storing the shadow memory respectively.
70  *
71  * The mapping between a virtual memory address and its corresponding shadow
72  * memory address is defined based on the formula:
73  *
74  *     shadow_addr = (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET
75  *
76  * where KASAN_SHADOW_SCALE_SHIFT is the order of the number of bits that map
77  * to a single shadow byte and KASAN_SHADOW_OFFSET is a constant that offsets
78  * the mapping. Note that KASAN_SHADOW_OFFSET does not point to the start of
79  * the shadow memory region.
80  *
81  * Based on this mapping, we define two constants:
82  *
83  *     KASAN_SHADOW_START: the start of the shadow memory region;
84  *     KASAN_SHADOW_END: the end of the shadow memory region.
85  *
86  * KASAN_SHADOW_END is defined first as the shadow address that corresponds to
87  * the upper bound of possible virtual kernel memory addresses UL(1) << 64
88  * according to the mapping formula.
89  *
90  * KASAN_SHADOW_START is defined second based on KASAN_SHADOW_END. The shadow
91  * memory start must map to the lowest possible kernel virtual memory address
92  * and thus it depends on the actual bitness of the address space.
93  *
94  * As KASAN inserts redzones between stack variables, this increases the stack
95  * memory usage significantly. Thus, we double the (minimum) stack size.
96  */
97 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
98 #define KASAN_SHADOW_OFFSET	_AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
99 #define KASAN_SHADOW_END	((UL(1) << (64 - KASAN_SHADOW_SCALE_SHIFT)) + KASAN_SHADOW_OFFSET)
100 #define _KASAN_SHADOW_START(va)	(KASAN_SHADOW_END - (UL(1) << ((va) - KASAN_SHADOW_SCALE_SHIFT)))
101 #define KASAN_SHADOW_START	_KASAN_SHADOW_START(vabits_actual)
102 #define PAGE_END		KASAN_SHADOW_START
103 #define KASAN_THREAD_SHIFT	1
104 #else
105 #define KASAN_THREAD_SHIFT	0
106 #define PAGE_END		(_PAGE_END(VA_BITS_MIN))
107 #endif /* CONFIG_KASAN */
108 
109 #define MIN_THREAD_SHIFT	(14 + KASAN_THREAD_SHIFT)
110 
111 /*
112  * VMAP'd stacks are allocated at page granularity, so we must ensure that such
113  * stacks are a multiple of page size.
114  */
115 #if defined(CONFIG_VMAP_STACK) && (MIN_THREAD_SHIFT < PAGE_SHIFT)
116 #define THREAD_SHIFT		PAGE_SHIFT
117 #else
118 #define THREAD_SHIFT		MIN_THREAD_SHIFT
119 #endif
120 
121 #if THREAD_SHIFT >= PAGE_SHIFT
122 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
123 #endif
124 
125 #define THREAD_SIZE		(UL(1) << THREAD_SHIFT)
126 
127 /*
128  * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
129  * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
130  * assembly.
131  */
132 #ifdef CONFIG_VMAP_STACK
133 #define THREAD_ALIGN		(2 * THREAD_SIZE)
134 #else
135 #define THREAD_ALIGN		THREAD_SIZE
136 #endif
137 
138 #define IRQ_STACK_SIZE		THREAD_SIZE
139 
140 #define OVERFLOW_STACK_SIZE	SZ_4K
141 
142 /*
143  * With the minimum frame size of [x29, x30], exactly half the combined
144  * sizes of the hyp and overflow stacks is the maximum size needed to
145  * save the unwinded stacktrace; plus an additional entry to delimit the
146  * end.
147  */
148 #define NVHE_STACKTRACE_SIZE	((OVERFLOW_STACK_SIZE + PAGE_SIZE) / 2 + sizeof(long))
149 
150 /*
151  * Alignment of kernel segments (e.g. .text, .data).
152  *
153  *  4 KB granule:  16 level 3 entries, with contiguous bit
154  * 16 KB granule:   4 level 3 entries, without contiguous bit
155  * 64 KB granule:   1 level 3 entry
156  */
157 #define SEGMENT_ALIGN		SZ_64K
158 
159 /*
160  * Memory types available.
161  *
162  * IMPORTANT: MT_NORMAL must be index 0 since vm_get_page_prot() may 'or' in
163  *	      the MT_NORMAL_TAGGED memory type for PROT_MTE mappings. Note
164  *	      that protection_map[] only contains MT_NORMAL attributes.
165  */
166 #define MT_NORMAL		0
167 #define MT_NORMAL_TAGGED	1
168 #define MT_NORMAL_NC		2
169 #define MT_DEVICE_nGnRnE	3
170 #define MT_DEVICE_nGnRE		4
171 
172 /*
173  * Memory types for Stage-2 translation
174  */
175 #define MT_S2_NORMAL		0xf
176 #define MT_S2_NORMAL_NC		0x5
177 #define MT_S2_DEVICE_nGnRE	0x1
178 
179 /*
180  * Memory types for Stage-2 translation when ID_AA64MMFR2_EL1.FWB is 0001
181  * Stage-2 enforces Normal-WB and Device-nGnRE
182  */
183 #define MT_S2_FWB_NORMAL	6
184 #define MT_S2_FWB_NORMAL_NC	5
185 #define MT_S2_FWB_DEVICE_nGnRE	1
186 
187 #ifdef CONFIG_ARM64_4K_PAGES
188 #define IOREMAP_MAX_ORDER	(PUD_SHIFT)
189 #else
190 #define IOREMAP_MAX_ORDER	(PMD_SHIFT)
191 #endif
192 
193 /*
194  *  Open-coded (swapper_pg_dir - reserved_pg_dir) as this cannot be calculated
195  *  until link time.
196  */
197 #define RESERVED_SWAPPER_OFFSET	(PAGE_SIZE)
198 
199 /*
200  *  Open-coded (swapper_pg_dir - tramp_pg_dir) as this cannot be calculated
201  *  until link time.
202  */
203 #define TRAMP_SWAPPER_OFFSET	(2 * PAGE_SIZE)
204 
205 #ifndef __ASSEMBLY__
206 
207 #include <linux/bitops.h>
208 #include <linux/compiler.h>
209 #include <linux/mmdebug.h>
210 #include <linux/types.h>
211 #include <asm/boot.h>
212 #include <asm/bug.h>
213 #include <asm/sections.h>
214 
215 #if VA_BITS > 48
216 extern u64			vabits_actual;
217 #else
218 #define vabits_actual		((u64)VA_BITS)
219 #endif
220 
221 extern s64			memstart_addr;
222 /* PHYS_OFFSET - the physical address of the start of memory. */
223 #define PHYS_OFFSET		({ VM_BUG_ON(memstart_addr & 1); memstart_addr; })
224 
225 /* the offset between the kernel virtual and physical mappings */
226 extern u64			kimage_voffset;
227 
228 static inline unsigned long kaslr_offset(void)
229 {
230 	return (u64)&_text - KIMAGE_VADDR;
231 }
232 
233 #ifdef CONFIG_RANDOMIZE_BASE
234 void kaslr_init(void);
235 static inline bool kaslr_enabled(void)
236 {
237 	extern bool __kaslr_is_enabled;
238 	return __kaslr_is_enabled;
239 }
240 #else
241 static inline void kaslr_init(void) { }
242 static inline bool kaslr_enabled(void) { return false; }
243 #endif
244 
245 /*
246  * Allow all memory at the discovery stage. We will clip it later.
247  */
248 #define MIN_MEMBLOCK_ADDR	0
249 #define MAX_MEMBLOCK_ADDR	U64_MAX
250 
251 /*
252  * PFNs are used to describe any physical page; this means
253  * PFN 0 == physical address 0.
254  *
255  * This is the PFN of the first RAM page in the kernel
256  * direct-mapped view.  We assume this is the first page
257  * of RAM in the mem_map as well.
258  */
259 #define PHYS_PFN_OFFSET	(PHYS_OFFSET >> PAGE_SHIFT)
260 
261 /*
262  * When dealing with data aborts, watchpoints, or instruction traps we may end
263  * up with a tagged userland pointer. Clear the tag to get a sane pointer to
264  * pass on to access_ok(), for instance.
265  */
266 #define __untagged_addr(addr)	\
267 	((__force __typeof__(addr))sign_extend64((__force u64)(addr), 55))
268 
269 #define untagged_addr(addr)	({					\
270 	u64 __addr = (__force u64)(addr);					\
271 	__addr &= __untagged_addr(__addr);				\
272 	(__force __typeof__(addr))__addr;				\
273 })
274 
275 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
276 #define __tag_shifted(tag)	((u64)(tag) << 56)
277 #define __tag_reset(addr)	__untagged_addr(addr)
278 #define __tag_get(addr)		(__u8)((u64)(addr) >> 56)
279 #else
280 #define __tag_shifted(tag)	0UL
281 #define __tag_reset(addr)	(addr)
282 #define __tag_get(addr)		0
283 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
284 
285 static inline const void *__tag_set(const void *addr, u8 tag)
286 {
287 	u64 __addr = (u64)addr & ~__tag_shifted(0xff);
288 	return (const void *)(__addr | __tag_shifted(tag));
289 }
290 
291 #ifdef CONFIG_KASAN_HW_TAGS
292 #define arch_enable_tag_checks_sync()		mte_enable_kernel_sync()
293 #define arch_enable_tag_checks_async()		mte_enable_kernel_async()
294 #define arch_enable_tag_checks_asymm()		mte_enable_kernel_asymm()
295 #define arch_suppress_tag_checks_start()	mte_enable_tco()
296 #define arch_suppress_tag_checks_stop()		mte_disable_tco()
297 #define arch_force_async_tag_fault()		mte_check_tfsr_exit()
298 #define arch_get_random_tag()			mte_get_random_tag()
299 #define arch_get_mem_tag(addr)			mte_get_mem_tag(addr)
300 #define arch_set_mem_tag_range(addr, size, tag, init)	\
301 			mte_set_mem_tag_range((addr), (size), (tag), (init))
302 #endif /* CONFIG_KASAN_HW_TAGS */
303 
304 /*
305  * Physical vs virtual RAM address space conversion.  These are
306  * private definitions which should NOT be used outside memory.h
307  * files.  Use virt_to_phys/phys_to_virt/__pa/__va instead.
308  */
309 
310 
311 /*
312  * Check whether an arbitrary address is within the linear map, which
313  * lives in the [PAGE_OFFSET, PAGE_END) interval at the bottom of the
314  * kernel's TTBR1 address range.
315  */
316 #define __is_lm_address(addr)	(((u64)(addr) - PAGE_OFFSET) < (PAGE_END - PAGE_OFFSET))
317 
318 #define __lm_to_phys(addr)	(((addr) - PAGE_OFFSET) + PHYS_OFFSET)
319 #define __kimg_to_phys(addr)	((addr) - kimage_voffset)
320 
321 #define __virt_to_phys_nodebug(x) ({					\
322 	phys_addr_t __x = (phys_addr_t)(__tag_reset(x));		\
323 	__is_lm_address(__x) ? __lm_to_phys(__x) : __kimg_to_phys(__x);	\
324 })
325 
326 #define __pa_symbol_nodebug(x)	__kimg_to_phys((phys_addr_t)(x))
327 
328 #ifdef CONFIG_DEBUG_VIRTUAL
329 extern phys_addr_t __virt_to_phys(unsigned long x);
330 extern phys_addr_t __phys_addr_symbol(unsigned long x);
331 #else
332 #define __virt_to_phys(x)	__virt_to_phys_nodebug(x)
333 #define __phys_addr_symbol(x)	__pa_symbol_nodebug(x)
334 #endif /* CONFIG_DEBUG_VIRTUAL */
335 
336 #define __phys_to_virt(x)	((unsigned long)((x) - PHYS_OFFSET) | PAGE_OFFSET)
337 #define __phys_to_kimg(x)	((unsigned long)((x) + kimage_voffset))
338 
339 /*
340  * Convert a page to/from a physical address
341  */
342 #define page_to_phys(page)	(__pfn_to_phys(page_to_pfn(page)))
343 #define phys_to_page(phys)	(pfn_to_page(__phys_to_pfn(phys)))
344 
345 /*
346  * Note: Drivers should NOT use these.  They are the wrong
347  * translation for translating DMA addresses.  Use the driver
348  * DMA support - see dma-mapping.h.
349  */
350 #define virt_to_phys virt_to_phys
351 static inline phys_addr_t virt_to_phys(const volatile void *x)
352 {
353 	return __virt_to_phys((unsigned long)(x));
354 }
355 
356 #define phys_to_virt phys_to_virt
357 static inline void *phys_to_virt(phys_addr_t x)
358 {
359 	return (void *)(__phys_to_virt(x));
360 }
361 
362 /* Needed already here for resolving __phys_to_pfn() in virt_to_pfn() */
363 #include <asm-generic/memory_model.h>
364 
365 static inline unsigned long virt_to_pfn(const void *kaddr)
366 {
367 	return __phys_to_pfn(virt_to_phys(kaddr));
368 }
369 
370 /*
371  * Drivers should NOT use these either.
372  */
373 #define __pa(x)			__virt_to_phys((unsigned long)(x))
374 #define __pa_symbol(x)		__phys_addr_symbol(RELOC_HIDE((unsigned long)(x), 0))
375 #define __pa_nodebug(x)		__virt_to_phys_nodebug((unsigned long)(x))
376 #define __va(x)			((void *)__phys_to_virt((phys_addr_t)(x)))
377 #define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
378 #define sym_to_pfn(x)		__phys_to_pfn(__pa_symbol(x))
379 
380 /*
381  *  virt_to_page(x)	convert a _valid_ virtual address to struct page *
382  *  virt_addr_valid(x)	indicates whether a virtual address is valid
383  */
384 #define ARCH_PFN_OFFSET		((unsigned long)PHYS_PFN_OFFSET)
385 
386 #if defined(CONFIG_DEBUG_VIRTUAL)
387 #define page_to_virt(x)	({						\
388 	__typeof__(x) __page = x;					\
389 	void *__addr = __va(page_to_phys(__page));			\
390 	(void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
391 })
392 #define virt_to_page(x)		pfn_to_page(virt_to_pfn(x))
393 #else
394 #define page_to_virt(x)	({						\
395 	__typeof__(x) __page = x;					\
396 	u64 __idx = ((u64)__page - VMEMMAP_START) / sizeof(struct page);\
397 	u64 __addr = PAGE_OFFSET + (__idx * PAGE_SIZE);			\
398 	(void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
399 })
400 
401 #define virt_to_page(x)	({						\
402 	u64 __idx = (__tag_reset((u64)x) - PAGE_OFFSET) / PAGE_SIZE;	\
403 	u64 __addr = VMEMMAP_START + (__idx * sizeof(struct page));	\
404 	(struct page *)__addr;						\
405 })
406 #endif /* CONFIG_DEBUG_VIRTUAL */
407 
408 #define virt_addr_valid(addr)	({					\
409 	__typeof__(addr) __addr = __tag_reset(addr);			\
410 	__is_lm_address(__addr) && pfn_is_map_memory(virt_to_pfn(__addr));	\
411 })
412 
413 void dump_mem_limit(void);
414 #endif /* !ASSEMBLY */
415 
416 /*
417  * Given that the GIC architecture permits ITS implementations that can only be
418  * configured with a LPI table address once, GICv3 systems with many CPUs may
419  * end up reserving a lot of different regions after a kexec for their LPI
420  * tables (one per CPU), as we are forced to reuse the same memory after kexec
421  * (and thus reserve it persistently with EFI beforehand)
422  */
423 #if defined(CONFIG_EFI) && defined(CONFIG_ARM_GIC_V3_ITS)
424 # define INIT_MEMBLOCK_RESERVED_REGIONS	(INIT_MEMBLOCK_REGIONS + NR_CPUS + 1)
425 #endif
426 
427 /*
428  * memory regions which marked with flag MEMBLOCK_NOMAP(for example, the memory
429  * of the EFI_UNUSABLE_MEMORY type) may divide a continuous memory block into
430  * multiple parts. As a result, the number of memory regions is large.
431  */
432 #ifdef CONFIG_EFI
433 #define INIT_MEMBLOCK_MEMORY_REGIONS	(INIT_MEMBLOCK_REGIONS * 8)
434 #endif
435 
436 
437 #endif /* __ASM_MEMORY_H */
438