xref: /linux/arch/arm64/include/asm/memory.h (revision 2fe3c78a2c26dd5ee811024a1b7d6cfb4d654319)
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_RANGE	(_PAGE_END(VA_BITS_MIN) - PAGE_OFFSET)
34 #define VMEMMAP_SIZE	((VMEMMAP_RANGE >> PAGE_SHIFT) * sizeof(struct page))
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		(VMEMMAP_END - VMEMMAP_SIZE)
51 #define VMEMMAP_END		(-UL(SZ_1G))
52 #define PCI_IO_START		(VMEMMAP_END + SZ_8M)
53 #define PCI_IO_END		(PCI_IO_START + PCI_IO_SIZE)
54 #define FIXADDR_TOP		(-UL(SZ_8M))
55 
56 #if VA_BITS > 48
57 #ifdef CONFIG_ARM64_16K_PAGES
58 #define VA_BITS_MIN		(47)
59 #else
60 #define VA_BITS_MIN		(48)
61 #endif
62 #else
63 #define VA_BITS_MIN		(VA_BITS)
64 #endif
65 
66 #define _PAGE_END(va)		(-(UL(1) << ((va) - 1)))
67 
68 #define KERNEL_START		_text
69 #define KERNEL_END		_end
70 
71 /*
72  * Generic and Software Tag-Based KASAN modes require 1/8th and 1/16th of the
73  * kernel virtual address space for storing the shadow memory respectively.
74  *
75  * The mapping between a virtual memory address and its corresponding shadow
76  * memory address is defined based on the formula:
77  *
78  *     shadow_addr = (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET
79  *
80  * where KASAN_SHADOW_SCALE_SHIFT is the order of the number of bits that map
81  * to a single shadow byte and KASAN_SHADOW_OFFSET is a constant that offsets
82  * the mapping. Note that KASAN_SHADOW_OFFSET does not point to the start of
83  * the shadow memory region.
84  *
85  * Based on this mapping, we define two constants:
86  *
87  *     KASAN_SHADOW_START: the start of the shadow memory region;
88  *     KASAN_SHADOW_END: the end of the shadow memory region.
89  *
90  * KASAN_SHADOW_END is defined first as the shadow address that corresponds to
91  * the upper bound of possible virtual kernel memory addresses UL(1) << 64
92  * according to the mapping formula.
93  *
94  * KASAN_SHADOW_START is defined second based on KASAN_SHADOW_END. The shadow
95  * memory start must map to the lowest possible kernel virtual memory address
96  * and thus it depends on the actual bitness of the address space.
97  *
98  * As KASAN inserts redzones between stack variables, this increases the stack
99  * memory usage significantly. Thus, we double the (minimum) stack size.
100  */
101 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
102 #define KASAN_SHADOW_OFFSET	_AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
103 #define KASAN_SHADOW_END	((UL(1) << (64 - KASAN_SHADOW_SCALE_SHIFT)) + KASAN_SHADOW_OFFSET)
104 #define _KASAN_SHADOW_START(va)	(KASAN_SHADOW_END - (UL(1) << ((va) - KASAN_SHADOW_SCALE_SHIFT)))
105 #define KASAN_SHADOW_START	_KASAN_SHADOW_START(vabits_actual)
106 #define PAGE_END		KASAN_SHADOW_START
107 #define KASAN_THREAD_SHIFT	1
108 #else
109 #define KASAN_THREAD_SHIFT	0
110 #define PAGE_END		(_PAGE_END(VA_BITS_MIN))
111 #endif /* CONFIG_KASAN */
112 
113 #define PHYSMEM_END		__pa(PAGE_END - 1)
114 
115 #define MIN_THREAD_SHIFT	(14 + KASAN_THREAD_SHIFT)
116 
117 /*
118  * VMAP'd stacks are allocated at page granularity, so we must ensure that such
119  * stacks are a multiple of page size.
120  */
121 #if defined(CONFIG_VMAP_STACK) && (MIN_THREAD_SHIFT < PAGE_SHIFT)
122 #define THREAD_SHIFT		PAGE_SHIFT
123 #else
124 #define THREAD_SHIFT		MIN_THREAD_SHIFT
125 #endif
126 
127 #if THREAD_SHIFT >= PAGE_SHIFT
128 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
129 #endif
130 
131 #define THREAD_SIZE		(UL(1) << THREAD_SHIFT)
132 
133 /*
134  * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
135  * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
136  * assembly.
137  */
138 #ifdef CONFIG_VMAP_STACK
139 #define THREAD_ALIGN		(2 * THREAD_SIZE)
140 #else
141 #define THREAD_ALIGN		THREAD_SIZE
142 #endif
143 
144 #define IRQ_STACK_SIZE		THREAD_SIZE
145 
146 #define OVERFLOW_STACK_SIZE	SZ_4K
147 
148 /*
149  * With the minimum frame size of [x29, x30], exactly half the combined
150  * sizes of the hyp and overflow stacks is the maximum size needed to
151  * save the unwinded stacktrace; plus an additional entry to delimit the
152  * end.
153  */
154 #define NVHE_STACKTRACE_SIZE	((OVERFLOW_STACK_SIZE + PAGE_SIZE) / 2 + sizeof(long))
155 
156 /*
157  * Alignment of kernel segments (e.g. .text, .data).
158  *
159  *  4 KB granule:  16 level 3 entries, with contiguous bit
160  * 16 KB granule:   4 level 3 entries, without contiguous bit
161  * 64 KB granule:   1 level 3 entry
162  */
163 #define SEGMENT_ALIGN		SZ_64K
164 
165 /*
166  * Memory types available.
167  *
168  * IMPORTANT: MT_NORMAL must be index 0 since vm_get_page_prot() may 'or' in
169  *	      the MT_NORMAL_TAGGED memory type for PROT_MTE mappings. Note
170  *	      that protection_map[] only contains MT_NORMAL attributes.
171  */
172 #define MT_NORMAL		0
173 #define MT_NORMAL_TAGGED	1
174 #define MT_NORMAL_NC		2
175 #define MT_DEVICE_nGnRnE	3
176 #define MT_DEVICE_nGnRE		4
177 
178 /*
179  * Memory types for Stage-2 translation
180  */
181 #define MT_S2_NORMAL		0xf
182 #define MT_S2_NORMAL_NC		0x5
183 #define MT_S2_DEVICE_nGnRE	0x1
184 
185 /*
186  * Memory types for Stage-2 translation when ID_AA64MMFR2_EL1.FWB is 0001
187  * Stage-2 enforces Normal-WB and Device-nGnRE
188  */
189 #define MT_S2_FWB_NORMAL	6
190 #define MT_S2_FWB_NORMAL_NC	5
191 #define MT_S2_FWB_DEVICE_nGnRE	1
192 
193 #ifdef CONFIG_ARM64_4K_PAGES
194 #define IOREMAP_MAX_ORDER	(PUD_SHIFT)
195 #else
196 #define IOREMAP_MAX_ORDER	(PMD_SHIFT)
197 #endif
198 
199 /*
200  *  Open-coded (swapper_pg_dir - reserved_pg_dir) as this cannot be calculated
201  *  until link time.
202  */
203 #define RESERVED_SWAPPER_OFFSET	(PAGE_SIZE)
204 
205 /*
206  *  Open-coded (swapper_pg_dir - tramp_pg_dir) as this cannot be calculated
207  *  until link time.
208  */
209 #define TRAMP_SWAPPER_OFFSET	(2 * PAGE_SIZE)
210 
211 #ifndef __ASSEMBLY__
212 
213 #include <linux/bitops.h>
214 #include <linux/compiler.h>
215 #include <linux/mmdebug.h>
216 #include <linux/types.h>
217 #include <asm/boot.h>
218 #include <asm/bug.h>
219 #include <asm/sections.h>
220 #include <asm/sysreg.h>
221 
222 static inline u64 __pure read_tcr(void)
223 {
224 	u64  tcr;
225 
226 	// read_sysreg() uses asm volatile, so avoid it here
227 	asm("mrs %0, tcr_el1" : "=r"(tcr));
228 	return tcr;
229 }
230 
231 #if VA_BITS > 48
232 // For reasons of #include hell, we can't use TCR_T1SZ_OFFSET/TCR_T1SZ_MASK here
233 #define vabits_actual		(64 - ((read_tcr() >> 16) & 63))
234 #else
235 #define vabits_actual		((u64)VA_BITS)
236 #endif
237 
238 extern s64			memstart_addr;
239 /* PHYS_OFFSET - the physical address of the start of memory. */
240 #define PHYS_OFFSET		({ VM_BUG_ON(memstart_addr & 1); memstart_addr; })
241 
242 /* the offset between the kernel virtual and physical mappings */
243 extern u64			kimage_voffset;
244 
245 static inline unsigned long kaslr_offset(void)
246 {
247 	return (u64)&_text - KIMAGE_VADDR;
248 }
249 
250 #ifdef CONFIG_RANDOMIZE_BASE
251 void kaslr_init(void);
252 static inline bool kaslr_enabled(void)
253 {
254 	extern bool __kaslr_is_enabled;
255 	return __kaslr_is_enabled;
256 }
257 #else
258 static inline void kaslr_init(void) { }
259 static inline bool kaslr_enabled(void) { return false; }
260 #endif
261 
262 /*
263  * Allow all memory at the discovery stage. We will clip it later.
264  */
265 #define MIN_MEMBLOCK_ADDR	0
266 #define MAX_MEMBLOCK_ADDR	U64_MAX
267 
268 /*
269  * PFNs are used to describe any physical page; this means
270  * PFN 0 == physical address 0.
271  *
272  * This is the PFN of the first RAM page in the kernel
273  * direct-mapped view.  We assume this is the first page
274  * of RAM in the mem_map as well.
275  */
276 #define PHYS_PFN_OFFSET	(PHYS_OFFSET >> PAGE_SHIFT)
277 
278 /*
279  * When dealing with data aborts, watchpoints, or instruction traps we may end
280  * up with a tagged userland pointer. Clear the tag to get a sane pointer to
281  * pass on to access_ok(), for instance.
282  */
283 #define __untagged_addr(addr)	\
284 	((__force __typeof__(addr))sign_extend64((__force u64)(addr), 55))
285 
286 #define untagged_addr(addr)	({					\
287 	u64 __addr = (__force u64)(addr);					\
288 	__addr &= __untagged_addr(__addr);				\
289 	(__force __typeof__(addr))__addr;				\
290 })
291 
292 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
293 #define __tag_shifted(tag)	((u64)(tag) << 56)
294 #define __tag_reset(addr)	__untagged_addr(addr)
295 #define __tag_get(addr)		(__u8)((u64)(addr) >> 56)
296 #else
297 #define __tag_shifted(tag)	0UL
298 #define __tag_reset(addr)	(addr)
299 #define __tag_get(addr)		0
300 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
301 
302 static inline const void *__tag_set(const void *addr, u8 tag)
303 {
304 	u64 __addr = (u64)addr & ~__tag_shifted(0xff);
305 	return (const void *)(__addr | __tag_shifted(tag));
306 }
307 
308 #ifdef CONFIG_KASAN_HW_TAGS
309 #define arch_enable_tag_checks_sync()		mte_enable_kernel_sync()
310 #define arch_enable_tag_checks_async()		mte_enable_kernel_async()
311 #define arch_enable_tag_checks_asymm()		mte_enable_kernel_asymm()
312 #define arch_suppress_tag_checks_start()	mte_enable_tco()
313 #define arch_suppress_tag_checks_stop()		mte_disable_tco()
314 #define arch_force_async_tag_fault()		mte_check_tfsr_exit()
315 #define arch_get_random_tag()			mte_get_random_tag()
316 #define arch_get_mem_tag(addr)			mte_get_mem_tag(addr)
317 #define arch_set_mem_tag_range(addr, size, tag, init)	\
318 			mte_set_mem_tag_range((addr), (size), (tag), (init))
319 #endif /* CONFIG_KASAN_HW_TAGS */
320 
321 /*
322  * Physical vs virtual RAM address space conversion.  These are
323  * private definitions which should NOT be used outside memory.h
324  * files.  Use virt_to_phys/phys_to_virt/__pa/__va instead.
325  */
326 
327 
328 /*
329  * Check whether an arbitrary address is within the linear map, which
330  * lives in the [PAGE_OFFSET, PAGE_END) interval at the bottom of the
331  * kernel's TTBR1 address range.
332  */
333 #define __is_lm_address(addr)	(((u64)(addr) - PAGE_OFFSET) < (PAGE_END - PAGE_OFFSET))
334 
335 #define __lm_to_phys(addr)	(((addr) - PAGE_OFFSET) + PHYS_OFFSET)
336 #define __kimg_to_phys(addr)	((addr) - kimage_voffset)
337 
338 #define __virt_to_phys_nodebug(x) ({					\
339 	phys_addr_t __x = (phys_addr_t)(__tag_reset(x));		\
340 	__is_lm_address(__x) ? __lm_to_phys(__x) : __kimg_to_phys(__x);	\
341 })
342 
343 #define __pa_symbol_nodebug(x)	__kimg_to_phys((phys_addr_t)(x))
344 
345 #ifdef CONFIG_DEBUG_VIRTUAL
346 extern phys_addr_t __virt_to_phys(unsigned long x);
347 extern phys_addr_t __phys_addr_symbol(unsigned long x);
348 #else
349 #define __virt_to_phys(x)	__virt_to_phys_nodebug(x)
350 #define __phys_addr_symbol(x)	__pa_symbol_nodebug(x)
351 #endif /* CONFIG_DEBUG_VIRTUAL */
352 
353 #define __phys_to_virt(x)	((unsigned long)((x) - PHYS_OFFSET) | PAGE_OFFSET)
354 #define __phys_to_kimg(x)	((unsigned long)((x) + kimage_voffset))
355 
356 /*
357  * Convert a page to/from a physical address
358  */
359 #define page_to_phys(page)	(__pfn_to_phys(page_to_pfn(page)))
360 #define phys_to_page(phys)	(pfn_to_page(__phys_to_pfn(phys)))
361 
362 /*
363  * Note: Drivers should NOT use these.  They are the wrong
364  * translation for translating DMA addresses.  Use the driver
365  * DMA support - see dma-mapping.h.
366  */
367 #define virt_to_phys virt_to_phys
368 static inline phys_addr_t virt_to_phys(const volatile void *x)
369 {
370 	return __virt_to_phys((unsigned long)(x));
371 }
372 
373 #define phys_to_virt phys_to_virt
374 static inline void *phys_to_virt(phys_addr_t x)
375 {
376 	return (void *)(__phys_to_virt(x));
377 }
378 
379 /* Needed already here for resolving __phys_to_pfn() in virt_to_pfn() */
380 #include <asm-generic/memory_model.h>
381 
382 static inline unsigned long virt_to_pfn(const void *kaddr)
383 {
384 	return __phys_to_pfn(virt_to_phys(kaddr));
385 }
386 
387 /*
388  * Drivers should NOT use these either.
389  */
390 #define __pa(x)			__virt_to_phys((unsigned long)(x))
391 #define __pa_symbol(x)		__phys_addr_symbol(RELOC_HIDE((unsigned long)(x), 0))
392 #define __pa_nodebug(x)		__virt_to_phys_nodebug((unsigned long)(x))
393 #define __va(x)			((void *)__phys_to_virt((phys_addr_t)(x)))
394 #define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
395 #define sym_to_pfn(x)		__phys_to_pfn(__pa_symbol(x))
396 
397 /*
398  *  virt_to_page(x)	convert a _valid_ virtual address to struct page *
399  *  virt_addr_valid(x)	indicates whether a virtual address is valid
400  */
401 #define ARCH_PFN_OFFSET		((unsigned long)PHYS_PFN_OFFSET)
402 
403 #if defined(CONFIG_DEBUG_VIRTUAL)
404 #define page_to_virt(x)	({						\
405 	__typeof__(x) __page = x;					\
406 	void *__addr = __va(page_to_phys(__page));			\
407 	(void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
408 })
409 #define virt_to_page(x)		pfn_to_page(virt_to_pfn(x))
410 #else
411 #define page_to_virt(x)	({						\
412 	__typeof__(x) __page = x;					\
413 	u64 __idx = ((u64)__page - VMEMMAP_START) / sizeof(struct page);\
414 	u64 __addr = PAGE_OFFSET + (__idx * PAGE_SIZE);			\
415 	(void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
416 })
417 
418 #define virt_to_page(x)	({						\
419 	u64 __idx = (__tag_reset((u64)x) - PAGE_OFFSET) / PAGE_SIZE;	\
420 	u64 __addr = VMEMMAP_START + (__idx * sizeof(struct page));	\
421 	(struct page *)__addr;						\
422 })
423 #endif /* CONFIG_DEBUG_VIRTUAL */
424 
425 #define virt_addr_valid(addr)	({					\
426 	__typeof__(addr) __addr = __tag_reset(addr);			\
427 	__is_lm_address(__addr) && pfn_is_map_memory(virt_to_pfn(__addr));	\
428 })
429 
430 void dump_mem_limit(void);
431 #endif /* !ASSEMBLY */
432 
433 /*
434  * Given that the GIC architecture permits ITS implementations that can only be
435  * configured with a LPI table address once, GICv3 systems with many CPUs may
436  * end up reserving a lot of different regions after a kexec for their LPI
437  * tables (one per CPU), as we are forced to reuse the same memory after kexec
438  * (and thus reserve it persistently with EFI beforehand)
439  */
440 #if defined(CONFIG_EFI) && defined(CONFIG_ARM_GIC_V3_ITS)
441 # define INIT_MEMBLOCK_RESERVED_REGIONS	(INIT_MEMBLOCK_REGIONS + NR_CPUS + 1)
442 #endif
443 
444 /*
445  * memory regions which marked with flag MEMBLOCK_NOMAP(for example, the memory
446  * of the EFI_UNUSABLE_MEMORY type) may divide a continuous memory block into
447  * multiple parts. As a result, the number of memory regions is large.
448  */
449 #ifdef CONFIG_EFI
450 #define INIT_MEMBLOCK_MEMORY_REGIONS	(INIT_MEMBLOCK_REGIONS * 8)
451 #endif
452 
453 
454 #endif /* __ASM_MEMORY_H */
455