xref: /openbmc/linux/arch/ia64/mm/init.c (revision f5ad1c74)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Initialize MMU support.
4  *
5  * Copyright (C) 1998-2003 Hewlett-Packard Co
6  *	David Mosberger-Tang <davidm@hpl.hp.com>
7  */
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 
11 #include <linux/dma-map-ops.h>
12 #include <linux/dmar.h>
13 #include <linux/efi.h>
14 #include <linux/elf.h>
15 #include <linux/memblock.h>
16 #include <linux/mm.h>
17 #include <linux/sched/signal.h>
18 #include <linux/mmzone.h>
19 #include <linux/module.h>
20 #include <linux/personality.h>
21 #include <linux/reboot.h>
22 #include <linux/slab.h>
23 #include <linux/swap.h>
24 #include <linux/proc_fs.h>
25 #include <linux/bitops.h>
26 #include <linux/kexec.h>
27 #include <linux/swiotlb.h>
28 
29 #include <asm/dma.h>
30 #include <asm/io.h>
31 #include <asm/numa.h>
32 #include <asm/patch.h>
33 #include <asm/pgalloc.h>
34 #include <asm/sal.h>
35 #include <asm/sections.h>
36 #include <asm/tlb.h>
37 #include <linux/uaccess.h>
38 #include <asm/unistd.h>
39 #include <asm/mca.h>
40 
41 extern void ia64_tlb_init (void);
42 
43 unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
44 
45 #ifdef CONFIG_VIRTUAL_MEM_MAP
46 unsigned long VMALLOC_END = VMALLOC_END_INIT;
47 EXPORT_SYMBOL(VMALLOC_END);
48 struct page *vmem_map;
49 EXPORT_SYMBOL(vmem_map);
50 #endif
51 
52 struct page *zero_page_memmap_ptr;	/* map entry for zero page */
53 EXPORT_SYMBOL(zero_page_memmap_ptr);
54 
55 void
56 __ia64_sync_icache_dcache (pte_t pte)
57 {
58 	unsigned long addr;
59 	struct page *page;
60 
61 	page = pte_page(pte);
62 	addr = (unsigned long) page_address(page);
63 
64 	if (test_bit(PG_arch_1, &page->flags))
65 		return;				/* i-cache is already coherent with d-cache */
66 
67 	flush_icache_range(addr, addr + page_size(page));
68 	set_bit(PG_arch_1, &page->flags);	/* mark page as clean */
69 }
70 
71 /*
72  * Since DMA is i-cache coherent, any (complete) pages that were written via
73  * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
74  * flush them when they get mapped into an executable vm-area.
75  */
76 void arch_dma_mark_clean(phys_addr_t paddr, size_t size)
77 {
78 	unsigned long pfn = PHYS_PFN(paddr);
79 
80 	do {
81 		set_bit(PG_arch_1, &pfn_to_page(pfn)->flags);
82 	} while (++pfn <= PHYS_PFN(paddr + size - 1));
83 }
84 
85 inline void
86 ia64_set_rbs_bot (void)
87 {
88 	unsigned long stack_size = rlimit_max(RLIMIT_STACK) & -16;
89 
90 	if (stack_size > MAX_USER_STACK_SIZE)
91 		stack_size = MAX_USER_STACK_SIZE;
92 	current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
93 }
94 
95 /*
96  * This performs some platform-dependent address space initialization.
97  * On IA-64, we want to setup the VM area for the register backing
98  * store (which grows upwards) and install the gateway page which is
99  * used for signal trampolines, etc.
100  */
101 void
102 ia64_init_addr_space (void)
103 {
104 	struct vm_area_struct *vma;
105 
106 	ia64_set_rbs_bot();
107 
108 	/*
109 	 * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
110 	 * the problem.  When the process attempts to write to the register backing store
111 	 * for the first time, it will get a SEGFAULT in this case.
112 	 */
113 	vma = vm_area_alloc(current->mm);
114 	if (vma) {
115 		vma_set_anonymous(vma);
116 		vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
117 		vma->vm_end = vma->vm_start + PAGE_SIZE;
118 		vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
119 		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
120 		mmap_write_lock(current->mm);
121 		if (insert_vm_struct(current->mm, vma)) {
122 			mmap_write_unlock(current->mm);
123 			vm_area_free(vma);
124 			return;
125 		}
126 		mmap_write_unlock(current->mm);
127 	}
128 
129 	/* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
130 	if (!(current->personality & MMAP_PAGE_ZERO)) {
131 		vma = vm_area_alloc(current->mm);
132 		if (vma) {
133 			vma_set_anonymous(vma);
134 			vma->vm_end = PAGE_SIZE;
135 			vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
136 			vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO |
137 					VM_DONTEXPAND | VM_DONTDUMP;
138 			mmap_write_lock(current->mm);
139 			if (insert_vm_struct(current->mm, vma)) {
140 				mmap_write_unlock(current->mm);
141 				vm_area_free(vma);
142 				return;
143 			}
144 			mmap_write_unlock(current->mm);
145 		}
146 	}
147 }
148 
149 void
150 free_initmem (void)
151 {
152 	free_reserved_area(ia64_imva(__init_begin), ia64_imva(__init_end),
153 			   -1, "unused kernel");
154 }
155 
156 void __init
157 free_initrd_mem (unsigned long start, unsigned long end)
158 {
159 	/*
160 	 * EFI uses 4KB pages while the kernel can use 4KB or bigger.
161 	 * Thus EFI and the kernel may have different page sizes. It is
162 	 * therefore possible to have the initrd share the same page as
163 	 * the end of the kernel (given current setup).
164 	 *
165 	 * To avoid freeing/using the wrong page (kernel sized) we:
166 	 *	- align up the beginning of initrd
167 	 *	- align down the end of initrd
168 	 *
169 	 *  |             |
170 	 *  |=============| a000
171 	 *  |             |
172 	 *  |             |
173 	 *  |             | 9000
174 	 *  |/////////////|
175 	 *  |/////////////|
176 	 *  |=============| 8000
177 	 *  |///INITRD////|
178 	 *  |/////////////|
179 	 *  |/////////////| 7000
180 	 *  |             |
181 	 *  |KKKKKKKKKKKKK|
182 	 *  |=============| 6000
183 	 *  |KKKKKKKKKKKKK|
184 	 *  |KKKKKKKKKKKKK|
185 	 *  K=kernel using 8KB pages
186 	 *
187 	 * In this example, we must free page 8000 ONLY. So we must align up
188 	 * initrd_start and keep initrd_end as is.
189 	 */
190 	start = PAGE_ALIGN(start);
191 	end = end & PAGE_MASK;
192 
193 	if (start < end)
194 		printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
195 
196 	for (; start < end; start += PAGE_SIZE) {
197 		if (!virt_addr_valid(start))
198 			continue;
199 		free_reserved_page(virt_to_page(start));
200 	}
201 }
202 
203 /*
204  * This installs a clean page in the kernel's page table.
205  */
206 static struct page * __init
207 put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
208 {
209 	pgd_t *pgd;
210 	p4d_t *p4d;
211 	pud_t *pud;
212 	pmd_t *pmd;
213 	pte_t *pte;
214 
215 	pgd = pgd_offset_k(address);		/* note: this is NOT pgd_offset()! */
216 
217 	{
218 		p4d = p4d_alloc(&init_mm, pgd, address);
219 		if (!p4d)
220 			goto out;
221 		pud = pud_alloc(&init_mm, p4d, address);
222 		if (!pud)
223 			goto out;
224 		pmd = pmd_alloc(&init_mm, pud, address);
225 		if (!pmd)
226 			goto out;
227 		pte = pte_alloc_kernel(pmd, address);
228 		if (!pte)
229 			goto out;
230 		if (!pte_none(*pte))
231 			goto out;
232 		set_pte(pte, mk_pte(page, pgprot));
233 	}
234   out:
235 	/* no need for flush_tlb */
236 	return page;
237 }
238 
239 static void __init
240 setup_gate (void)
241 {
242 	struct page *page;
243 
244 	/*
245 	 * Map the gate page twice: once read-only to export the ELF
246 	 * headers etc. and once execute-only page to enable
247 	 * privilege-promotion via "epc":
248 	 */
249 	page = virt_to_page(ia64_imva(__start_gate_section));
250 	put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
251 #ifdef HAVE_BUGGY_SEGREL
252 	page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
253 	put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
254 #else
255 	put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
256 	/* Fill in the holes (if any) with read-only zero pages: */
257 	{
258 		unsigned long addr;
259 
260 		for (addr = GATE_ADDR + PAGE_SIZE;
261 		     addr < GATE_ADDR + PERCPU_PAGE_SIZE;
262 		     addr += PAGE_SIZE)
263 		{
264 			put_kernel_page(ZERO_PAGE(0), addr,
265 					PAGE_READONLY);
266 			put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
267 					PAGE_READONLY);
268 		}
269 	}
270 #endif
271 	ia64_patch_gate();
272 }
273 
274 static struct vm_area_struct gate_vma;
275 
276 static int __init gate_vma_init(void)
277 {
278 	vma_init(&gate_vma, NULL);
279 	gate_vma.vm_start = FIXADDR_USER_START;
280 	gate_vma.vm_end = FIXADDR_USER_END;
281 	gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
282 	gate_vma.vm_page_prot = __P101;
283 
284 	return 0;
285 }
286 __initcall(gate_vma_init);
287 
288 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
289 {
290 	return &gate_vma;
291 }
292 
293 int in_gate_area_no_mm(unsigned long addr)
294 {
295 	if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
296 		return 1;
297 	return 0;
298 }
299 
300 int in_gate_area(struct mm_struct *mm, unsigned long addr)
301 {
302 	return in_gate_area_no_mm(addr);
303 }
304 
305 void ia64_mmu_init(void *my_cpu_data)
306 {
307 	unsigned long pta, impl_va_bits;
308 	extern void tlb_init(void);
309 
310 #ifdef CONFIG_DISABLE_VHPT
311 #	define VHPT_ENABLE_BIT	0
312 #else
313 #	define VHPT_ENABLE_BIT	1
314 #endif
315 
316 	/*
317 	 * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
318 	 * address space.  The IA-64 architecture guarantees that at least 50 bits of
319 	 * virtual address space are implemented but if we pick a large enough page size
320 	 * (e.g., 64KB), the mapped address space is big enough that it will overlap with
321 	 * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
322 	 * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
323 	 * problem in practice.  Alternatively, we could truncate the top of the mapped
324 	 * address space to not permit mappings that would overlap with the VMLPT.
325 	 * --davidm 00/12/06
326 	 */
327 #	define pte_bits			3
328 #	define mapped_space_bits	(3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
329 	/*
330 	 * The virtual page table has to cover the entire implemented address space within
331 	 * a region even though not all of this space may be mappable.  The reason for
332 	 * this is that the Access bit and Dirty bit fault handlers perform
333 	 * non-speculative accesses to the virtual page table, so the address range of the
334 	 * virtual page table itself needs to be covered by virtual page table.
335 	 */
336 #	define vmlpt_bits		(impl_va_bits - PAGE_SHIFT + pte_bits)
337 #	define POW2(n)			(1ULL << (n))
338 
339 	impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
340 
341 	if (impl_va_bits < 51 || impl_va_bits > 61)
342 		panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
343 	/*
344 	 * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
345 	 * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
346 	 * the test makes sure that our mapped space doesn't overlap the
347 	 * unimplemented hole in the middle of the region.
348 	 */
349 	if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
350 	    (mapped_space_bits > impl_va_bits - 1))
351 		panic("Cannot build a big enough virtual-linear page table"
352 		      " to cover mapped address space.\n"
353 		      " Try using a smaller page size.\n");
354 
355 
356 	/* place the VMLPT at the end of each page-table mapped region: */
357 	pta = POW2(61) - POW2(vmlpt_bits);
358 
359 	/*
360 	 * Set the (virtually mapped linear) page table address.  Bit
361 	 * 8 selects between the short and long format, bits 2-7 the
362 	 * size of the table, and bit 0 whether the VHPT walker is
363 	 * enabled.
364 	 */
365 	ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
366 
367 	ia64_tlb_init();
368 
369 #ifdef	CONFIG_HUGETLB_PAGE
370 	ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
371 	ia64_srlz_d();
372 #endif
373 }
374 
375 #ifdef CONFIG_VIRTUAL_MEM_MAP
376 int vmemmap_find_next_valid_pfn(int node, int i)
377 {
378 	unsigned long end_address, hole_next_pfn;
379 	unsigned long stop_address;
380 	pg_data_t *pgdat = NODE_DATA(node);
381 
382 	end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
383 	end_address = PAGE_ALIGN(end_address);
384 	stop_address = (unsigned long) &vmem_map[pgdat_end_pfn(pgdat)];
385 
386 	do {
387 		pgd_t *pgd;
388 		p4d_t *p4d;
389 		pud_t *pud;
390 		pmd_t *pmd;
391 		pte_t *pte;
392 
393 		pgd = pgd_offset_k(end_address);
394 		if (pgd_none(*pgd)) {
395 			end_address += PGDIR_SIZE;
396 			continue;
397 		}
398 
399 		p4d = p4d_offset(pgd, end_address);
400 		if (p4d_none(*p4d)) {
401 			end_address += P4D_SIZE;
402 			continue;
403 		}
404 
405 		pud = pud_offset(p4d, end_address);
406 		if (pud_none(*pud)) {
407 			end_address += PUD_SIZE;
408 			continue;
409 		}
410 
411 		pmd = pmd_offset(pud, end_address);
412 		if (pmd_none(*pmd)) {
413 			end_address += PMD_SIZE;
414 			continue;
415 		}
416 
417 		pte = pte_offset_kernel(pmd, end_address);
418 retry_pte:
419 		if (pte_none(*pte)) {
420 			end_address += PAGE_SIZE;
421 			pte++;
422 			if ((end_address < stop_address) &&
423 			    (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
424 				goto retry_pte;
425 			continue;
426 		}
427 		/* Found next valid vmem_map page */
428 		break;
429 	} while (end_address < stop_address);
430 
431 	end_address = min(end_address, stop_address);
432 	end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
433 	hole_next_pfn = end_address / sizeof(struct page);
434 	return hole_next_pfn - pgdat->node_start_pfn;
435 }
436 
437 int __init create_mem_map_page_table(u64 start, u64 end, void *arg)
438 {
439 	unsigned long address, start_page, end_page;
440 	struct page *map_start, *map_end;
441 	int node;
442 	pgd_t *pgd;
443 	p4d_t *p4d;
444 	pud_t *pud;
445 	pmd_t *pmd;
446 	pte_t *pte;
447 
448 	map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
449 	map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
450 
451 	start_page = (unsigned long) map_start & PAGE_MASK;
452 	end_page = PAGE_ALIGN((unsigned long) map_end);
453 	node = paddr_to_nid(__pa(start));
454 
455 	for (address = start_page; address < end_page; address += PAGE_SIZE) {
456 		pgd = pgd_offset_k(address);
457 		if (pgd_none(*pgd)) {
458 			p4d = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
459 			if (!p4d)
460 				goto err_alloc;
461 			pgd_populate(&init_mm, pgd, p4d);
462 		}
463 		p4d = p4d_offset(pgd, address);
464 
465 		if (p4d_none(*p4d)) {
466 			pud = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
467 			if (!pud)
468 				goto err_alloc;
469 			p4d_populate(&init_mm, p4d, pud);
470 		}
471 		pud = pud_offset(p4d, address);
472 
473 		if (pud_none(*pud)) {
474 			pmd = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
475 			if (!pmd)
476 				goto err_alloc;
477 			pud_populate(&init_mm, pud, pmd);
478 		}
479 		pmd = pmd_offset(pud, address);
480 
481 		if (pmd_none(*pmd)) {
482 			pte = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
483 			if (!pte)
484 				goto err_alloc;
485 			pmd_populate_kernel(&init_mm, pmd, pte);
486 		}
487 		pte = pte_offset_kernel(pmd, address);
488 
489 		if (pte_none(*pte)) {
490 			void *page = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE,
491 							 node);
492 			if (!page)
493 				goto err_alloc;
494 			set_pte(pte, pfn_pte(__pa(page) >> PAGE_SHIFT,
495 					     PAGE_KERNEL));
496 		}
497 	}
498 	return 0;
499 
500 err_alloc:
501 	panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d\n",
502 	      __func__, PAGE_SIZE, PAGE_SIZE, node);
503 	return -ENOMEM;
504 }
505 
506 struct memmap_init_callback_data {
507 	struct page *start;
508 	struct page *end;
509 	int nid;
510 	unsigned long zone;
511 };
512 
513 static int __meminit
514 virtual_memmap_init(u64 start, u64 end, void *arg)
515 {
516 	struct memmap_init_callback_data *args;
517 	struct page *map_start, *map_end;
518 
519 	args = (struct memmap_init_callback_data *) arg;
520 	map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
521 	map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
522 
523 	if (map_start < args->start)
524 		map_start = args->start;
525 	if (map_end > args->end)
526 		map_end = args->end;
527 
528 	/*
529 	 * We have to initialize "out of bounds" struct page elements that fit completely
530 	 * on the same pages that were allocated for the "in bounds" elements because they
531 	 * may be referenced later (and found to be "reserved").
532 	 */
533 	map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
534 	map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
535 		    / sizeof(struct page));
536 
537 	if (map_start < map_end)
538 		memmap_init_zone((unsigned long)(map_end - map_start),
539 				 args->nid, args->zone, page_to_pfn(map_start),
540 				 MEMINIT_EARLY, NULL, MIGRATE_MOVABLE);
541 	return 0;
542 }
543 
544 void __meminit
545 memmap_init (unsigned long size, int nid, unsigned long zone,
546 	     unsigned long start_pfn)
547 {
548 	if (!vmem_map) {
549 		memmap_init_zone(size, nid, zone, start_pfn,
550 				 MEMINIT_EARLY, NULL, MIGRATE_MOVABLE);
551 	} else {
552 		struct page *start;
553 		struct memmap_init_callback_data args;
554 
555 		start = pfn_to_page(start_pfn);
556 		args.start = start;
557 		args.end = start + size;
558 		args.nid = nid;
559 		args.zone = zone;
560 
561 		efi_memmap_walk(virtual_memmap_init, &args);
562 	}
563 }
564 
565 int
566 ia64_pfn_valid (unsigned long pfn)
567 {
568 	char byte;
569 	struct page *pg = pfn_to_page(pfn);
570 
571 	return     (__get_user(byte, (char __user *) pg) == 0)
572 		&& ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
573 			|| (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
574 }
575 EXPORT_SYMBOL(ia64_pfn_valid);
576 
577 #endif /* CONFIG_VIRTUAL_MEM_MAP */
578 
579 int __init register_active_ranges(u64 start, u64 len, int nid)
580 {
581 	u64 end = start + len;
582 
583 #ifdef CONFIG_KEXEC
584 	if (start > crashk_res.start && start < crashk_res.end)
585 		start = crashk_res.end;
586 	if (end > crashk_res.start && end < crashk_res.end)
587 		end = crashk_res.start;
588 #endif
589 
590 	if (start < end)
591 		memblock_add_node(__pa(start), end - start, nid);
592 	return 0;
593 }
594 
595 int
596 find_max_min_low_pfn (u64 start, u64 end, void *arg)
597 {
598 	unsigned long pfn_start, pfn_end;
599 #ifdef CONFIG_FLATMEM
600 	pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
601 	pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
602 #else
603 	pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
604 	pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
605 #endif
606 	min_low_pfn = min(min_low_pfn, pfn_start);
607 	max_low_pfn = max(max_low_pfn, pfn_end);
608 	return 0;
609 }
610 
611 /*
612  * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
613  * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
614  * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
615  * useful for performance testing, but conceivably could also come in handy for debugging
616  * purposes.
617  */
618 
619 static int nolwsys __initdata;
620 
621 static int __init
622 nolwsys_setup (char *s)
623 {
624 	nolwsys = 1;
625 	return 1;
626 }
627 
628 __setup("nolwsys", nolwsys_setup);
629 
630 void __init
631 mem_init (void)
632 {
633 	int i;
634 
635 	BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
636 	BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
637 	BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
638 
639 	/*
640 	 * This needs to be called _after_ the command line has been parsed but
641 	 * _before_ any drivers that may need the PCI DMA interface are
642 	 * initialized or bootmem has been freed.
643 	 */
644 #ifdef CONFIG_INTEL_IOMMU
645 	detect_intel_iommu();
646 	if (!iommu_detected)
647 #endif
648 #ifdef CONFIG_SWIOTLB
649 		swiotlb_init(1);
650 #endif
651 
652 #ifdef CONFIG_FLATMEM
653 	BUG_ON(!mem_map);
654 #endif
655 
656 	set_max_mapnr(max_low_pfn);
657 	high_memory = __va(max_low_pfn * PAGE_SIZE);
658 	memblock_free_all();
659 	mem_init_print_info(NULL);
660 
661 	/*
662 	 * For fsyscall entrpoints with no light-weight handler, use the ordinary
663 	 * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
664 	 * code can tell them apart.
665 	 */
666 	for (i = 0; i < NR_syscalls; ++i) {
667 		extern unsigned long fsyscall_table[NR_syscalls];
668 		extern unsigned long sys_call_table[NR_syscalls];
669 
670 		if (!fsyscall_table[i] || nolwsys)
671 			fsyscall_table[i] = sys_call_table[i] | 1;
672 	}
673 	setup_gate();
674 }
675 
676 #ifdef CONFIG_MEMORY_HOTPLUG
677 int arch_add_memory(int nid, u64 start, u64 size,
678 		    struct mhp_params *params)
679 {
680 	unsigned long start_pfn = start >> PAGE_SHIFT;
681 	unsigned long nr_pages = size >> PAGE_SHIFT;
682 	int ret;
683 
684 	if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
685 		return -EINVAL;
686 
687 	ret = __add_pages(nid, start_pfn, nr_pages, params);
688 	if (ret)
689 		printk("%s: Problem encountered in __add_pages() as ret=%d\n",
690 		       __func__,  ret);
691 
692 	return ret;
693 }
694 
695 void arch_remove_memory(int nid, u64 start, u64 size,
696 			struct vmem_altmap *altmap)
697 {
698 	unsigned long start_pfn = start >> PAGE_SHIFT;
699 	unsigned long nr_pages = size >> PAGE_SHIFT;
700 
701 	__remove_pages(start_pfn, nr_pages, altmap);
702 }
703 #endif
704