xref: /openbmc/linux/arch/arm64/include/asm/memory.h (revision abcda807)
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_SIZE ((_PAGE_END(VA_BITS_MIN) - PAGE_OFFSET) \
34 			>> (PAGE_SHIFT - STRUCT_PAGE_MAX_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 BPF_JIT_REGION_START	(KASAN_SHADOW_END)
48 #define BPF_JIT_REGION_SIZE	(SZ_128M)
49 #define BPF_JIT_REGION_END	(BPF_JIT_REGION_START + BPF_JIT_REGION_SIZE)
50 #define MODULES_END		(MODULES_VADDR + MODULES_VSIZE)
51 #define MODULES_VADDR		(BPF_JIT_REGION_END)
52 #define MODULES_VSIZE		(SZ_128M)
53 #define VMEMMAP_START		(-VMEMMAP_SIZE - SZ_2M)
54 #define VMEMMAP_END		(VMEMMAP_START + VMEMMAP_SIZE)
55 #define PCI_IO_END		(VMEMMAP_START - SZ_2M)
56 #define PCI_IO_START		(PCI_IO_END - PCI_IO_SIZE)
57 #define FIXADDR_TOP		(PCI_IO_START - SZ_2M)
58 
59 #if VA_BITS > 48
60 #define VA_BITS_MIN		(48)
61 #else
62 #define VA_BITS_MIN		(VA_BITS)
63 #endif
64 
65 #define _PAGE_END(va)		(-(UL(1) << ((va) - 1)))
66 
67 #define KERNEL_START		_text
68 #define KERNEL_END		_end
69 
70 /*
71  * Generic and tag-based KASAN require 1/8th and 1/16th of the kernel virtual
72  * address space for the shadow region respectively. They can bloat the stack
73  * significantly, so double the (minimum) stack size when they are in use.
74  */
75 #ifdef CONFIG_KASAN
76 #define KASAN_SHADOW_OFFSET	_AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
77 #define KASAN_SHADOW_END	((UL(1) << (64 - KASAN_SHADOW_SCALE_SHIFT)) \
78 					+ KASAN_SHADOW_OFFSET)
79 #define KASAN_THREAD_SHIFT	1
80 #else
81 #define KASAN_THREAD_SHIFT	0
82 #define KASAN_SHADOW_END	(_PAGE_END(VA_BITS_MIN))
83 #endif /* CONFIG_KASAN */
84 
85 #define MIN_THREAD_SHIFT	(14 + KASAN_THREAD_SHIFT)
86 
87 /*
88  * VMAP'd stacks are allocated at page granularity, so we must ensure that such
89  * stacks are a multiple of page size.
90  */
91 #if defined(CONFIG_VMAP_STACK) && (MIN_THREAD_SHIFT < PAGE_SHIFT)
92 #define THREAD_SHIFT		PAGE_SHIFT
93 #else
94 #define THREAD_SHIFT		MIN_THREAD_SHIFT
95 #endif
96 
97 #if THREAD_SHIFT >= PAGE_SHIFT
98 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
99 #endif
100 
101 #define THREAD_SIZE		(UL(1) << THREAD_SHIFT)
102 
103 /*
104  * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
105  * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
106  * assembly.
107  */
108 #ifdef CONFIG_VMAP_STACK
109 #define THREAD_ALIGN		(2 * THREAD_SIZE)
110 #else
111 #define THREAD_ALIGN		THREAD_SIZE
112 #endif
113 
114 #define IRQ_STACK_SIZE		THREAD_SIZE
115 
116 #define OVERFLOW_STACK_SIZE	SZ_4K
117 
118 /*
119  * Alignment of kernel segments (e.g. .text, .data).
120  *
121  *  4 KB granule:  16 level 3 entries, with contiguous bit
122  * 16 KB granule:   4 level 3 entries, without contiguous bit
123  * 64 KB granule:   1 level 3 entry
124  */
125 #define SEGMENT_ALIGN		SZ_64K
126 
127 /*
128  * Memory types available.
129  *
130  * IMPORTANT: MT_NORMAL must be index 0 since vm_get_page_prot() may 'or' in
131  *	      the MT_NORMAL_TAGGED memory type for PROT_MTE mappings. Note
132  *	      that protection_map[] only contains MT_NORMAL attributes.
133  */
134 #define MT_NORMAL		0
135 #define MT_NORMAL_TAGGED	1
136 #define MT_NORMAL_NC		2
137 #define MT_NORMAL_WT		3
138 #define MT_DEVICE_nGnRnE	4
139 #define MT_DEVICE_nGnRE		5
140 #define MT_DEVICE_GRE		6
141 
142 /*
143  * Memory types for Stage-2 translation
144  */
145 #define MT_S2_NORMAL		0xf
146 #define MT_S2_DEVICE_nGnRE	0x1
147 
148 /*
149  * Memory types for Stage-2 translation when ID_AA64MMFR2_EL1.FWB is 0001
150  * Stage-2 enforces Normal-WB and Device-nGnRE
151  */
152 #define MT_S2_FWB_NORMAL	6
153 #define MT_S2_FWB_DEVICE_nGnRE	1
154 
155 #ifdef CONFIG_ARM64_4K_PAGES
156 #define IOREMAP_MAX_ORDER	(PUD_SHIFT)
157 #else
158 #define IOREMAP_MAX_ORDER	(PMD_SHIFT)
159 #endif
160 
161 #ifndef __ASSEMBLY__
162 
163 #include <linux/bitops.h>
164 #include <linux/compiler.h>
165 #include <linux/mmdebug.h>
166 #include <linux/types.h>
167 #include <asm/bug.h>
168 
169 extern u64			vabits_actual;
170 #define PAGE_END		(_PAGE_END(vabits_actual))
171 
172 extern s64			memstart_addr;
173 /* PHYS_OFFSET - the physical address of the start of memory. */
174 #define PHYS_OFFSET		({ VM_BUG_ON(memstart_addr & 1); memstart_addr; })
175 
176 /* the virtual base of the kernel image */
177 extern u64			kimage_vaddr;
178 
179 /* the offset between the kernel virtual and physical mappings */
180 extern u64			kimage_voffset;
181 
182 static inline unsigned long kaslr_offset(void)
183 {
184 	return kimage_vaddr - KIMAGE_VADDR;
185 }
186 
187 /*
188  * Allow all memory at the discovery stage. We will clip it later.
189  */
190 #define MIN_MEMBLOCK_ADDR	0
191 #define MAX_MEMBLOCK_ADDR	U64_MAX
192 
193 /*
194  * PFNs are used to describe any physical page; this means
195  * PFN 0 == physical address 0.
196  *
197  * This is the PFN of the first RAM page in the kernel
198  * direct-mapped view.  We assume this is the first page
199  * of RAM in the mem_map as well.
200  */
201 #define PHYS_PFN_OFFSET	(PHYS_OFFSET >> PAGE_SHIFT)
202 
203 /*
204  * When dealing with data aborts, watchpoints, or instruction traps we may end
205  * up with a tagged userland pointer. Clear the tag to get a sane pointer to
206  * pass on to access_ok(), for instance.
207  */
208 #define __untagged_addr(addr)	\
209 	((__force __typeof__(addr))sign_extend64((__force u64)(addr), 55))
210 
211 #define untagged_addr(addr)	({					\
212 	u64 __addr = (__force u64)(addr);					\
213 	__addr &= __untagged_addr(__addr);				\
214 	(__force __typeof__(addr))__addr;				\
215 })
216 
217 #ifdef CONFIG_KASAN_SW_TAGS
218 #define __tag_shifted(tag)	((u64)(tag) << 56)
219 #define __tag_reset(addr)	__untagged_addr(addr)
220 #define __tag_get(addr)		(__u8)((u64)(addr) >> 56)
221 #else
222 #define __tag_shifted(tag)	0UL
223 #define __tag_reset(addr)	(addr)
224 #define __tag_get(addr)		0
225 #endif /* CONFIG_KASAN_SW_TAGS */
226 
227 static inline const void *__tag_set(const void *addr, u8 tag)
228 {
229 	u64 __addr = (u64)addr & ~__tag_shifted(0xff);
230 	return (const void *)(__addr | __tag_shifted(tag));
231 }
232 
233 /*
234  * Physical vs virtual RAM address space conversion.  These are
235  * private definitions which should NOT be used outside memory.h
236  * files.  Use virt_to_phys/phys_to_virt/__pa/__va instead.
237  */
238 
239 
240 /*
241  * The linear kernel range starts at the bottom of the virtual address
242  * space. Testing the top bit for the start of the region is a
243  * sufficient check and avoids having to worry about the tag.
244  */
245 #define __is_lm_address(addr)	(!(((u64)addr) & BIT(vabits_actual - 1)))
246 
247 #define __lm_to_phys(addr)	(((addr) & ~PAGE_OFFSET) + PHYS_OFFSET)
248 #define __kimg_to_phys(addr)	((addr) - kimage_voffset)
249 
250 #define __virt_to_phys_nodebug(x) ({					\
251 	phys_addr_t __x = (phys_addr_t)(__tag_reset(x));		\
252 	__is_lm_address(__x) ? __lm_to_phys(__x) : __kimg_to_phys(__x);	\
253 })
254 
255 #define __pa_symbol_nodebug(x)	__kimg_to_phys((phys_addr_t)(x))
256 
257 #ifdef CONFIG_DEBUG_VIRTUAL
258 extern phys_addr_t __virt_to_phys(unsigned long x);
259 extern phys_addr_t __phys_addr_symbol(unsigned long x);
260 #else
261 #define __virt_to_phys(x)	__virt_to_phys_nodebug(x)
262 #define __phys_addr_symbol(x)	__pa_symbol_nodebug(x)
263 #endif /* CONFIG_DEBUG_VIRTUAL */
264 
265 #define __phys_to_virt(x)	((unsigned long)((x) - PHYS_OFFSET) | PAGE_OFFSET)
266 #define __phys_to_kimg(x)	((unsigned long)((x) + kimage_voffset))
267 
268 /*
269  * Convert a page to/from a physical address
270  */
271 #define page_to_phys(page)	(__pfn_to_phys(page_to_pfn(page)))
272 #define phys_to_page(phys)	(pfn_to_page(__phys_to_pfn(phys)))
273 
274 /*
275  * Note: Drivers should NOT use these.  They are the wrong
276  * translation for translating DMA addresses.  Use the driver
277  * DMA support - see dma-mapping.h.
278  */
279 #define virt_to_phys virt_to_phys
280 static inline phys_addr_t virt_to_phys(const volatile void *x)
281 {
282 	return __virt_to_phys((unsigned long)(x));
283 }
284 
285 #define phys_to_virt phys_to_virt
286 static inline void *phys_to_virt(phys_addr_t x)
287 {
288 	return (void *)(__phys_to_virt(x));
289 }
290 
291 /*
292  * Drivers should NOT use these either.
293  */
294 #define __pa(x)			__virt_to_phys((unsigned long)(x))
295 #define __pa_symbol(x)		__phys_addr_symbol(RELOC_HIDE((unsigned long)(x), 0))
296 #define __pa_nodebug(x)		__virt_to_phys_nodebug((unsigned long)(x))
297 #define __va(x)			((void *)__phys_to_virt((phys_addr_t)(x)))
298 #define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
299 #define virt_to_pfn(x)		__phys_to_pfn(__virt_to_phys((unsigned long)(x)))
300 #define sym_to_pfn(x)		__phys_to_pfn(__pa_symbol(x))
301 
302 /*
303  *  virt_to_page(x)	convert a _valid_ virtual address to struct page *
304  *  virt_addr_valid(x)	indicates whether a virtual address is valid
305  */
306 #define ARCH_PFN_OFFSET		((unsigned long)PHYS_PFN_OFFSET)
307 
308 #if !defined(CONFIG_SPARSEMEM_VMEMMAP) || defined(CONFIG_DEBUG_VIRTUAL)
309 #define virt_to_page(x)		pfn_to_page(virt_to_pfn(x))
310 #else
311 #define page_to_virt(x)	({						\
312 	__typeof__(x) __page = x;					\
313 	u64 __idx = ((u64)__page - VMEMMAP_START) / sizeof(struct page);\
314 	u64 __addr = PAGE_OFFSET + (__idx * PAGE_SIZE);			\
315 	(void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
316 })
317 
318 #define virt_to_page(x)	({						\
319 	u64 __idx = (__tag_reset((u64)x) - PAGE_OFFSET) / PAGE_SIZE;	\
320 	u64 __addr = VMEMMAP_START + (__idx * sizeof(struct page));	\
321 	(struct page *)__addr;						\
322 })
323 #endif /* !CONFIG_SPARSEMEM_VMEMMAP || CONFIG_DEBUG_VIRTUAL */
324 
325 #define virt_addr_valid(addr)	({					\
326 	__typeof__(addr) __addr = addr;					\
327 	__is_lm_address(__addr) && pfn_valid(virt_to_pfn(__addr));	\
328 })
329 
330 void dump_mem_limit(void);
331 #endif /* !ASSEMBLY */
332 
333 /*
334  * Given that the GIC architecture permits ITS implementations that can only be
335  * configured with a LPI table address once, GICv3 systems with many CPUs may
336  * end up reserving a lot of different regions after a kexec for their LPI
337  * tables (one per CPU), as we are forced to reuse the same memory after kexec
338  * (and thus reserve it persistently with EFI beforehand)
339  */
340 #if defined(CONFIG_EFI) && defined(CONFIG_ARM_GIC_V3_ITS)
341 # define INIT_MEMBLOCK_RESERVED_REGIONS	(INIT_MEMBLOCK_REGIONS + NR_CPUS + 1)
342 #endif
343 
344 #include <asm-generic/memory_model.h>
345 
346 #endif /* __ASM_MEMORY_H */
347