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  
read_tcr(void)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  
kaslr_offset(void)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);
kaslr_enabled(void)252  static inline bool kaslr_enabled(void)
253  {
254  	extern bool __kaslr_is_enabled;
255  	return __kaslr_is_enabled;
256  }
257  #else
kaslr_init(void)258  static inline void kaslr_init(void) { }
kaslr_enabled(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  
__tag_set(const void * addr,u8 tag)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
virt_to_phys(const volatile void * x)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
phys_to_virt(phys_addr_t x)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  
virt_to_pfn(const void * kaddr)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