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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * PowerPC version
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5 *
6 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
7 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
8 * Copyright (C) 1996 Paul Mackerras
9 *
10 * Derived from "arch/i386/mm/init.c"
11 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
12 *
13 * Dave Engebretsen <engebret@us.ibm.com>
14 * Rework for PPC64 port.
15 */
16
17#undef DEBUG
18
19#include <linux/signal.h>
20#include <linux/sched.h>
21#include <linux/kernel.h>
22#include <linux/errno.h>
23#include <linux/string.h>
24#include <linux/types.h>
25#include <linux/mman.h>
26#include <linux/mm.h>
27#include <linux/swap.h>
28#include <linux/stddef.h>
29#include <linux/vmalloc.h>
30#include <linux/init.h>
31#include <linux/delay.h>
32#include <linux/highmem.h>
33#include <linux/idr.h>
34#include <linux/nodemask.h>
35#include <linux/module.h>
36#include <linux/poison.h>
37#include <linux/memblock.h>
38#include <linux/hugetlb.h>
39#include <linux/slab.h>
40#include <linux/of_fdt.h>
41#include <linux/libfdt.h>
42#include <linux/memremap.h>
43
44#include <asm/pgalloc.h>
45#include <asm/page.h>
46#include <asm/prom.h>
47#include <asm/rtas.h>
48#include <asm/io.h>
49#include <asm/mmu_context.h>
50#include <asm/mmu.h>
51#include <linux/uaccess.h>
52#include <asm/smp.h>
53#include <asm/machdep.h>
54#include <asm/tlb.h>
55#include <asm/eeh.h>
56#include <asm/processor.h>
57#include <asm/mmzone.h>
58#include <asm/cputable.h>
59#include <asm/sections.h>
60#include <asm/iommu.h>
61#include <asm/vdso.h>
62#include <asm/hugetlb.h>
63
64#include <mm/mmu_decl.h>
65
66#ifdef CONFIG_SPARSEMEM_VMEMMAP
67/*
68 * Given an address within the vmemmap, determine the page that
69 * represents the start of the subsection it is within. Note that we have to
70 * do this by hand as the proffered address may not be correctly aligned.
71 * Subtraction of non-aligned pointers produces undefined results.
72 */
73static struct page * __meminit vmemmap_subsection_start(unsigned long vmemmap_addr)
74{
75 unsigned long start_pfn;
76 unsigned long offset = vmemmap_addr - ((unsigned long)(vmemmap));
77
78 /* Return the pfn of the start of the section. */
79 start_pfn = (offset / sizeof(struct page)) & PAGE_SUBSECTION_MASK;
80 return pfn_to_page(start_pfn);
81}
82
83/*
84 * Since memory is added in sub-section chunks, before creating a new vmemmap
85 * mapping, the kernel should check whether there is an existing memmap mapping
86 * covering the new subsection added. This is needed because kernel can map
87 * vmemmap area using 16MB pages which will cover a memory range of 16G. Such
88 * a range covers multiple subsections (2M)
89 *
90 * If any subsection in the 16G range mapped by vmemmap is valid we consider the
91 * vmemmap populated (There is a page table entry already present). We can't do
92 * a page table lookup here because with the hash translation we don't keep
93 * vmemmap details in linux page table.
94 */
95static int __meminit vmemmap_populated(unsigned long vmemmap_addr, int vmemmap_map_size)
96{
97 struct page *start;
98 unsigned long vmemmap_end = vmemmap_addr + vmemmap_map_size;
99 start = vmemmap_subsection_start(vmemmap_addr);
100
101 for (; (unsigned long)start < vmemmap_end; start += PAGES_PER_SUBSECTION)
102 /*
103 * pfn valid check here is intended to really check
104 * whether we have any subsection already initialized
105 * in this range.
106 */
107 if (pfn_valid(page_to_pfn(start)))
108 return 1;
109
110 return 0;
111}
112
113/*
114 * vmemmap virtual address space management does not have a traditional page
115 * table to track which virtual struct pages are backed by physical mapping.
116 * The virtual to physical mappings are tracked in a simple linked list
117 * format. 'vmemmap_list' maintains the entire vmemmap physical mapping at
118 * all times where as the 'next' list maintains the available
119 * vmemmap_backing structures which have been deleted from the
120 * 'vmemmap_global' list during system runtime (memory hotplug remove
121 * operation). The freed 'vmemmap_backing' structures are reused later when
122 * new requests come in without allocating fresh memory. This pointer also
123 * tracks the allocated 'vmemmap_backing' structures as we allocate one
124 * full page memory at a time when we dont have any.
125 */
126struct vmemmap_backing *vmemmap_list;
127static struct vmemmap_backing *next;
128
129/*
130 * The same pointer 'next' tracks individual chunks inside the allocated
131 * full page during the boot time and again tracks the freed nodes during
132 * runtime. It is racy but it does not happen as they are separated by the
133 * boot process. Will create problem if some how we have memory hotplug
134 * operation during boot !!
135 */
136static int num_left;
137static int num_freed;
138
139static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node)
140{
141 struct vmemmap_backing *vmem_back;
142 /* get from freed entries first */
143 if (num_freed) {
144 num_freed--;
145 vmem_back = next;
146 next = next->list;
147
148 return vmem_back;
149 }
150
151 /* allocate a page when required and hand out chunks */
152 if (!num_left) {
153 next = vmemmap_alloc_block(PAGE_SIZE, node);
154 if (unlikely(!next)) {
155 WARN_ON(1);
156 return NULL;
157 }
158 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing);
159 }
160
161 num_left--;
162
163 return next++;
164}
165
166static __meminit int vmemmap_list_populate(unsigned long phys,
167 unsigned long start,
168 int node)
169{
170 struct vmemmap_backing *vmem_back;
171
172 vmem_back = vmemmap_list_alloc(node);
173 if (unlikely(!vmem_back)) {
174 pr_debug("vmemap list allocation failed\n");
175 return -ENOMEM;
176 }
177
178 vmem_back->phys = phys;
179 vmem_back->virt_addr = start;
180 vmem_back->list = vmemmap_list;
181
182 vmemmap_list = vmem_back;
183 return 0;
184}
185
186static bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long start,
187 unsigned long page_size)
188{
189 unsigned long nr_pfn = page_size / sizeof(struct page);
190 unsigned long start_pfn = page_to_pfn((struct page *)start);
191
192 if ((start_pfn + nr_pfn) > altmap->end_pfn)
193 return true;
194
195 if (start_pfn < altmap->base_pfn)
196 return true;
197
198 return false;
199}
200
201int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
202 struct vmem_altmap *altmap)
203{
204 bool altmap_alloc;
205 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
206
207 /* Align to the page size of the linear mapping. */
208 start = ALIGN_DOWN(start, page_size);
209
210 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node);
211
212 for (; start < end; start += page_size) {
213 void *p = NULL;
214 int rc;
215
216 /*
217 * This vmemmap range is backing different subsections. If any
218 * of that subsection is marked valid, that means we already
219 * have initialized a page table covering this range and hence
220 * the vmemmap range is populated.
221 */
222 if (vmemmap_populated(start, page_size))
223 continue;
224
225 /*
226 * Allocate from the altmap first if we have one. This may
227 * fail due to alignment issues when using 16MB hugepages, so
228 * fall back to system memory if the altmap allocation fail.
229 */
230 if (altmap && !altmap_cross_boundary(altmap, start, page_size)) {
231 p = vmemmap_alloc_block_buf(page_size, node, altmap);
232 if (!p)
233 pr_debug("altmap block allocation failed, falling back to system memory");
234 else
235 altmap_alloc = true;
236 }
237 if (!p) {
238 p = vmemmap_alloc_block_buf(page_size, node, NULL);
239 altmap_alloc = false;
240 }
241 if (!p)
242 return -ENOMEM;
243
244 if (vmemmap_list_populate(__pa(p), start, node)) {
245 /*
246 * If we don't populate vmemap list, we don't have
247 * the ability to free the allocated vmemmap
248 * pages in section_deactivate. Hence free them
249 * here.
250 */
251 int nr_pfns = page_size >> PAGE_SHIFT;
252 unsigned long page_order = get_order(page_size);
253
254 if (altmap_alloc)
255 vmem_altmap_free(altmap, nr_pfns);
256 else
257 free_pages((unsigned long)p, page_order);
258 return -ENOMEM;
259 }
260
261 pr_debug(" * %016lx..%016lx allocated at %p\n",
262 start, start + page_size, p);
263
264 rc = vmemmap_create_mapping(start, page_size, __pa(p));
265 if (rc < 0) {
266 pr_warn("%s: Unable to create vmemmap mapping: %d\n",
267 __func__, rc);
268 return -EFAULT;
269 }
270 }
271
272 return 0;
273}
274
275#ifdef CONFIG_MEMORY_HOTPLUG
276static unsigned long vmemmap_list_free(unsigned long start)
277{
278 struct vmemmap_backing *vmem_back, *vmem_back_prev;
279
280 vmem_back_prev = vmem_back = vmemmap_list;
281
282 /* look for it with prev pointer recorded */
283 for (; vmem_back; vmem_back = vmem_back->list) {
284 if (vmem_back->virt_addr == start)
285 break;
286 vmem_back_prev = vmem_back;
287 }
288
289 if (unlikely(!vmem_back))
290 return 0;
291
292 /* remove it from vmemmap_list */
293 if (vmem_back == vmemmap_list) /* remove head */
294 vmemmap_list = vmem_back->list;
295 else
296 vmem_back_prev->list = vmem_back->list;
297
298 /* next point to this freed entry */
299 vmem_back->list = next;
300 next = vmem_back;
301 num_freed++;
302
303 return vmem_back->phys;
304}
305
306void __ref vmemmap_free(unsigned long start, unsigned long end,
307 struct vmem_altmap *altmap)
308{
309 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
310 unsigned long page_order = get_order(page_size);
311 unsigned long alt_start = ~0, alt_end = ~0;
312 unsigned long base_pfn;
313
314 start = ALIGN_DOWN(start, page_size);
315 if (altmap) {
316 alt_start = altmap->base_pfn;
317 alt_end = altmap->base_pfn + altmap->reserve +
318 altmap->free + altmap->alloc + altmap->align;
319 }
320
321 pr_debug("vmemmap_free %lx...%lx\n", start, end);
322
323 for (; start < end; start += page_size) {
324 unsigned long nr_pages, addr;
325 struct page *page;
326
327 /*
328 * We have already marked the subsection we are trying to remove
329 * invalid. So if we want to remove the vmemmap range, we
330 * need to make sure there is no subsection marked valid
331 * in this range.
332 */
333 if (vmemmap_populated(start, page_size))
334 continue;
335
336 addr = vmemmap_list_free(start);
337 if (!addr)
338 continue;
339
340 page = pfn_to_page(addr >> PAGE_SHIFT);
341 nr_pages = 1 << page_order;
342 base_pfn = PHYS_PFN(addr);
343
344 if (base_pfn >= alt_start && base_pfn < alt_end) {
345 vmem_altmap_free(altmap, nr_pages);
346 } else if (PageReserved(page)) {
347 /* allocated from bootmem */
348 if (page_size < PAGE_SIZE) {
349 /*
350 * this shouldn't happen, but if it is
351 * the case, leave the memory there
352 */
353 WARN_ON_ONCE(1);
354 } else {
355 while (nr_pages--)
356 free_reserved_page(page++);
357 }
358 } else {
359 free_pages((unsigned long)(__va(addr)), page_order);
360 }
361
362 vmemmap_remove_mapping(start, page_size);
363 }
364}
365#endif
366void register_page_bootmem_memmap(unsigned long section_nr,
367 struct page *start_page, unsigned long size)
368{
369}
370
371#endif /* CONFIG_SPARSEMEM_VMEMMAP */
372
373#ifdef CONFIG_PPC_BOOK3S_64
374unsigned int mmu_lpid_bits;
375#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
376EXPORT_SYMBOL_GPL(mmu_lpid_bits);
377#endif
378unsigned int mmu_pid_bits;
379
380static bool disable_radix = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT);
381
382static int __init parse_disable_radix(char *p)
383{
384 bool val;
385
386 if (!p)
387 val = true;
388 else if (kstrtobool(p, &val))
389 return -EINVAL;
390
391 disable_radix = val;
392
393 return 0;
394}
395early_param("disable_radix", parse_disable_radix);
396
397/*
398 * If we're running under a hypervisor, we need to check the contents of
399 * /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do
400 * radix. If not, we clear the radix feature bit so we fall back to hash.
401 */
402static void __init early_check_vec5(void)
403{
404 unsigned long root, chosen;
405 int size;
406 const u8 *vec5;
407 u8 mmu_supported;
408
409 root = of_get_flat_dt_root();
410 chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
411 if (chosen == -FDT_ERR_NOTFOUND) {
412 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
413 return;
414 }
415 vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size);
416 if (!vec5) {
417 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
418 return;
419 }
420 if (size <= OV5_INDX(OV5_MMU_SUPPORT)) {
421 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
422 return;
423 }
424
425 /* Check for supported configuration */
426 mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] &
427 OV5_FEAT(OV5_MMU_SUPPORT);
428 if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) {
429 /* Hypervisor only supports radix - check enabled && GTSE */
430 if (!early_radix_enabled()) {
431 pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
432 }
433 if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] &
434 OV5_FEAT(OV5_RADIX_GTSE))) {
435 cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
436 } else
437 cur_cpu_spec->mmu_features |= MMU_FTR_GTSE;
438 /* Do radix anyway - the hypervisor said we had to */
439 cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
440 } else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) {
441 /* Hypervisor only supports hash - disable radix */
442 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
443 cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
444 }
445}
446
447static int __init dt_scan_mmu_pid_width(unsigned long node,
448 const char *uname, int depth,
449 void *data)
450{
451 int size = 0;
452 const __be32 *prop;
453 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
454
455 /* We are scanning "cpu" nodes only */
456 if (type == NULL || strcmp(type, "cpu") != 0)
457 return 0;
458
459 /* Find MMU LPID, PID register size */
460 prop = of_get_flat_dt_prop(node, "ibm,mmu-lpid-bits", &size);
461 if (prop && size == 4)
462 mmu_lpid_bits = be32_to_cpup(prop);
463
464 prop = of_get_flat_dt_prop(node, "ibm,mmu-pid-bits", &size);
465 if (prop && size == 4)
466 mmu_pid_bits = be32_to_cpup(prop);
467
468 if (!mmu_pid_bits && !mmu_lpid_bits)
469 return 0;
470
471 return 1;
472}
473
474void __init mmu_early_init_devtree(void)
475{
476 bool hvmode = !!(mfmsr() & MSR_HV);
477
478 /* Disable radix mode based on kernel command line. */
479 if (disable_radix) {
480 if (IS_ENABLED(CONFIG_PPC_64S_HASH_MMU))
481 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
482 else
483 pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
484 }
485
486 of_scan_flat_dt(dt_scan_mmu_pid_width, NULL);
487 if (hvmode && !mmu_lpid_bits) {
488 if (early_cpu_has_feature(CPU_FTR_ARCH_207S))
489 mmu_lpid_bits = 12; /* POWER8-10 */
490 else
491 mmu_lpid_bits = 10; /* POWER7 */
492 }
493 if (!mmu_pid_bits) {
494 if (early_cpu_has_feature(CPU_FTR_ARCH_300))
495 mmu_pid_bits = 20; /* POWER9-10 */
496 }
497
498 /*
499 * Check /chosen/ibm,architecture-vec-5 if running as a guest.
500 * When running bare-metal, we can use radix if we like
501 * even though the ibm,architecture-vec-5 property created by
502 * skiboot doesn't have the necessary bits set.
503 */
504 if (!hvmode)
505 early_check_vec5();
506
507 if (early_radix_enabled()) {
508 radix__early_init_devtree();
509
510 /*
511 * We have finalized the translation we are going to use by now.
512 * Radix mode is not limited by RMA / VRMA addressing.
513 * Hence don't limit memblock allocations.
514 */
515 ppc64_rma_size = ULONG_MAX;
516 memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
517 } else
518 hash__early_init_devtree();
519
520 if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
521 hugetlbpage_init_defaultsize();
522
523 if (!(cur_cpu_spec->mmu_features & MMU_FTR_HPTE_TABLE) &&
524 !(cur_cpu_spec->mmu_features & MMU_FTR_TYPE_RADIX))
525 panic("kernel does not support any MMU type offered by platform");
526}
527#endif /* CONFIG_PPC_BOOK3S_64 */
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * PowerPC version
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5 *
6 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
7 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
8 * Copyright (C) 1996 Paul Mackerras
9 *
10 * Derived from "arch/i386/mm/init.c"
11 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
12 *
13 * Dave Engebretsen <engebret@us.ibm.com>
14 * Rework for PPC64 port.
15 */
16
17#undef DEBUG
18
19#include <linux/signal.h>
20#include <linux/sched.h>
21#include <linux/kernel.h>
22#include <linux/errno.h>
23#include <linux/string.h>
24#include <linux/types.h>
25#include <linux/mman.h>
26#include <linux/mm.h>
27#include <linux/swap.h>
28#include <linux/stddef.h>
29#include <linux/vmalloc.h>
30#include <linux/init.h>
31#include <linux/delay.h>
32#include <linux/highmem.h>
33#include <linux/idr.h>
34#include <linux/nodemask.h>
35#include <linux/module.h>
36#include <linux/poison.h>
37#include <linux/memblock.h>
38#include <linux/hugetlb.h>
39#include <linux/slab.h>
40#include <linux/of_fdt.h>
41#include <linux/libfdt.h>
42#include <linux/memremap.h>
43
44#include <asm/pgalloc.h>
45#include <asm/page.h>
46#include <asm/prom.h>
47#include <asm/rtas.h>
48#include <asm/io.h>
49#include <asm/mmu_context.h>
50#include <asm/mmu.h>
51#include <linux/uaccess.h>
52#include <asm/smp.h>
53#include <asm/machdep.h>
54#include <asm/tlb.h>
55#include <asm/eeh.h>
56#include <asm/processor.h>
57#include <asm/mmzone.h>
58#include <asm/cputable.h>
59#include <asm/sections.h>
60#include <asm/iommu.h>
61#include <asm/vdso.h>
62
63#include <mm/mmu_decl.h>
64
65#ifdef CONFIG_SPARSEMEM_VMEMMAP
66/*
67 * Given an address within the vmemmap, determine the page that
68 * represents the start of the subsection it is within. Note that we have to
69 * do this by hand as the proffered address may not be correctly aligned.
70 * Subtraction of non-aligned pointers produces undefined results.
71 */
72static struct page * __meminit vmemmap_subsection_start(unsigned long vmemmap_addr)
73{
74 unsigned long start_pfn;
75 unsigned long offset = vmemmap_addr - ((unsigned long)(vmemmap));
76
77 /* Return the pfn of the start of the section. */
78 start_pfn = (offset / sizeof(struct page)) & PAGE_SUBSECTION_MASK;
79 return pfn_to_page(start_pfn);
80}
81
82/*
83 * Since memory is added in sub-section chunks, before creating a new vmemmap
84 * mapping, the kernel should check whether there is an existing memmap mapping
85 * covering the new subsection added. This is needed because kernel can map
86 * vmemmap area using 16MB pages which will cover a memory range of 16G. Such
87 * a range covers multiple subsections (2M)
88 *
89 * If any subsection in the 16G range mapped by vmemmap is valid we consider the
90 * vmemmap populated (There is a page table entry already present). We can't do
91 * a page table lookup here because with the hash translation we don't keep
92 * vmemmap details in linux page table.
93 */
94static int __meminit vmemmap_populated(unsigned long vmemmap_addr, int vmemmap_map_size)
95{
96 struct page *start;
97 unsigned long vmemmap_end = vmemmap_addr + vmemmap_map_size;
98 start = vmemmap_subsection_start(vmemmap_addr);
99
100 for (; (unsigned long)start < vmemmap_end; start += PAGES_PER_SUBSECTION)
101 /*
102 * pfn valid check here is intended to really check
103 * whether we have any subsection already initialized
104 * in this range.
105 */
106 if (pfn_valid(page_to_pfn(start)))
107 return 1;
108
109 return 0;
110}
111
112/*
113 * vmemmap virtual address space management does not have a traditonal page
114 * table to track which virtual struct pages are backed by physical mapping.
115 * The virtual to physical mappings are tracked in a simple linked list
116 * format. 'vmemmap_list' maintains the entire vmemmap physical mapping at
117 * all times where as the 'next' list maintains the available
118 * vmemmap_backing structures which have been deleted from the
119 * 'vmemmap_global' list during system runtime (memory hotplug remove
120 * operation). The freed 'vmemmap_backing' structures are reused later when
121 * new requests come in without allocating fresh memory. This pointer also
122 * tracks the allocated 'vmemmap_backing' structures as we allocate one
123 * full page memory at a time when we dont have any.
124 */
125struct vmemmap_backing *vmemmap_list;
126static struct vmemmap_backing *next;
127
128/*
129 * The same pointer 'next' tracks individual chunks inside the allocated
130 * full page during the boot time and again tracks the freeed nodes during
131 * runtime. It is racy but it does not happen as they are separated by the
132 * boot process. Will create problem if some how we have memory hotplug
133 * operation during boot !!
134 */
135static int num_left;
136static int num_freed;
137
138static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node)
139{
140 struct vmemmap_backing *vmem_back;
141 /* get from freed entries first */
142 if (num_freed) {
143 num_freed--;
144 vmem_back = next;
145 next = next->list;
146
147 return vmem_back;
148 }
149
150 /* allocate a page when required and hand out chunks */
151 if (!num_left) {
152 next = vmemmap_alloc_block(PAGE_SIZE, node);
153 if (unlikely(!next)) {
154 WARN_ON(1);
155 return NULL;
156 }
157 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing);
158 }
159
160 num_left--;
161
162 return next++;
163}
164
165static __meminit void vmemmap_list_populate(unsigned long phys,
166 unsigned long start,
167 int node)
168{
169 struct vmemmap_backing *vmem_back;
170
171 vmem_back = vmemmap_list_alloc(node);
172 if (unlikely(!vmem_back)) {
173 WARN_ON(1);
174 return;
175 }
176
177 vmem_back->phys = phys;
178 vmem_back->virt_addr = start;
179 vmem_back->list = vmemmap_list;
180
181 vmemmap_list = vmem_back;
182}
183
184static bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long start,
185 unsigned long page_size)
186{
187 unsigned long nr_pfn = page_size / sizeof(struct page);
188 unsigned long start_pfn = page_to_pfn((struct page *)start);
189
190 if ((start_pfn + nr_pfn) > altmap->end_pfn)
191 return true;
192
193 if (start_pfn < altmap->base_pfn)
194 return true;
195
196 return false;
197}
198
199int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
200 struct vmem_altmap *altmap)
201{
202 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
203
204 /* Align to the page size of the linear mapping. */
205 start = ALIGN_DOWN(start, page_size);
206
207 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node);
208
209 for (; start < end; start += page_size) {
210 void *p = NULL;
211 int rc;
212
213 /*
214 * This vmemmap range is backing different subsections. If any
215 * of that subsection is marked valid, that means we already
216 * have initialized a page table covering this range and hence
217 * the vmemmap range is populated.
218 */
219 if (vmemmap_populated(start, page_size))
220 continue;
221
222 /*
223 * Allocate from the altmap first if we have one. This may
224 * fail due to alignment issues when using 16MB hugepages, so
225 * fall back to system memory if the altmap allocation fail.
226 */
227 if (altmap && !altmap_cross_boundary(altmap, start, page_size)) {
228 p = vmemmap_alloc_block_buf(page_size, node, altmap);
229 if (!p)
230 pr_debug("altmap block allocation failed, falling back to system memory");
231 }
232 if (!p)
233 p = vmemmap_alloc_block_buf(page_size, node, NULL);
234 if (!p)
235 return -ENOMEM;
236
237 vmemmap_list_populate(__pa(p), start, node);
238
239 pr_debug(" * %016lx..%016lx allocated at %p\n",
240 start, start + page_size, p);
241
242 rc = vmemmap_create_mapping(start, page_size, __pa(p));
243 if (rc < 0) {
244 pr_warn("%s: Unable to create vmemmap mapping: %d\n",
245 __func__, rc);
246 return -EFAULT;
247 }
248 }
249
250 return 0;
251}
252
253#ifdef CONFIG_MEMORY_HOTPLUG
254static unsigned long vmemmap_list_free(unsigned long start)
255{
256 struct vmemmap_backing *vmem_back, *vmem_back_prev;
257
258 vmem_back_prev = vmem_back = vmemmap_list;
259
260 /* look for it with prev pointer recorded */
261 for (; vmem_back; vmem_back = vmem_back->list) {
262 if (vmem_back->virt_addr == start)
263 break;
264 vmem_back_prev = vmem_back;
265 }
266
267 if (unlikely(!vmem_back)) {
268 WARN_ON(1);
269 return 0;
270 }
271
272 /* remove it from vmemmap_list */
273 if (vmem_back == vmemmap_list) /* remove head */
274 vmemmap_list = vmem_back->list;
275 else
276 vmem_back_prev->list = vmem_back->list;
277
278 /* next point to this freed entry */
279 vmem_back->list = next;
280 next = vmem_back;
281 num_freed++;
282
283 return vmem_back->phys;
284}
285
286void __ref vmemmap_free(unsigned long start, unsigned long end,
287 struct vmem_altmap *altmap)
288{
289 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
290 unsigned long page_order = get_order(page_size);
291 unsigned long alt_start = ~0, alt_end = ~0;
292 unsigned long base_pfn;
293
294 start = ALIGN_DOWN(start, page_size);
295 if (altmap) {
296 alt_start = altmap->base_pfn;
297 alt_end = altmap->base_pfn + altmap->reserve +
298 altmap->free + altmap->alloc + altmap->align;
299 }
300
301 pr_debug("vmemmap_free %lx...%lx\n", start, end);
302
303 for (; start < end; start += page_size) {
304 unsigned long nr_pages, addr;
305 struct page *page;
306
307 /*
308 * We have already marked the subsection we are trying to remove
309 * invalid. So if we want to remove the vmemmap range, we
310 * need to make sure there is no subsection marked valid
311 * in this range.
312 */
313 if (vmemmap_populated(start, page_size))
314 continue;
315
316 addr = vmemmap_list_free(start);
317 if (!addr)
318 continue;
319
320 page = pfn_to_page(addr >> PAGE_SHIFT);
321 nr_pages = 1 << page_order;
322 base_pfn = PHYS_PFN(addr);
323
324 if (base_pfn >= alt_start && base_pfn < alt_end) {
325 vmem_altmap_free(altmap, nr_pages);
326 } else if (PageReserved(page)) {
327 /* allocated from bootmem */
328 if (page_size < PAGE_SIZE) {
329 /*
330 * this shouldn't happen, but if it is
331 * the case, leave the memory there
332 */
333 WARN_ON_ONCE(1);
334 } else {
335 while (nr_pages--)
336 free_reserved_page(page++);
337 }
338 } else {
339 free_pages((unsigned long)(__va(addr)), page_order);
340 }
341
342 vmemmap_remove_mapping(start, page_size);
343 }
344}
345#endif
346void register_page_bootmem_memmap(unsigned long section_nr,
347 struct page *start_page, unsigned long size)
348{
349}
350
351#endif /* CONFIG_SPARSEMEM_VMEMMAP */
352
353#ifdef CONFIG_PPC_BOOK3S_64
354static bool disable_radix = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT);
355
356static int __init parse_disable_radix(char *p)
357{
358 bool val;
359
360 if (!p)
361 val = true;
362 else if (kstrtobool(p, &val))
363 return -EINVAL;
364
365 disable_radix = val;
366
367 return 0;
368}
369early_param("disable_radix", parse_disable_radix);
370
371/*
372 * If we're running under a hypervisor, we need to check the contents of
373 * /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do
374 * radix. If not, we clear the radix feature bit so we fall back to hash.
375 */
376static void __init early_check_vec5(void)
377{
378 unsigned long root, chosen;
379 int size;
380 const u8 *vec5;
381 u8 mmu_supported;
382
383 root = of_get_flat_dt_root();
384 chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
385 if (chosen == -FDT_ERR_NOTFOUND) {
386 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
387 return;
388 }
389 vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size);
390 if (!vec5) {
391 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
392 return;
393 }
394 if (size <= OV5_INDX(OV5_MMU_SUPPORT)) {
395 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
396 return;
397 }
398
399 /* Check for supported configuration */
400 mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] &
401 OV5_FEAT(OV5_MMU_SUPPORT);
402 if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) {
403 /* Hypervisor only supports radix - check enabled && GTSE */
404 if (!early_radix_enabled()) {
405 pr_warn("WARNING: Ignoring cmdline option disable_radix\n");
406 }
407 if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] &
408 OV5_FEAT(OV5_RADIX_GTSE))) {
409 cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
410 } else
411 cur_cpu_spec->mmu_features |= MMU_FTR_GTSE;
412 /* Do radix anyway - the hypervisor said we had to */
413 cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX;
414 } else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) {
415 /* Hypervisor only supports hash - disable radix */
416 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
417 cur_cpu_spec->mmu_features &= ~MMU_FTR_GTSE;
418 }
419}
420
421void __init mmu_early_init_devtree(void)
422{
423 /* Disable radix mode based on kernel command line. */
424 if (disable_radix)
425 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX;
426
427 /*
428 * Check /chosen/ibm,architecture-vec-5 if running as a guest.
429 * When running bare-metal, we can use radix if we like
430 * even though the ibm,architecture-vec-5 property created by
431 * skiboot doesn't have the necessary bits set.
432 */
433 if (!(mfmsr() & MSR_HV))
434 early_check_vec5();
435
436 if (early_radix_enabled()) {
437 radix__early_init_devtree();
438 /*
439 * We have finalized the translation we are going to use by now.
440 * Radix mode is not limited by RMA / VRMA addressing.
441 * Hence don't limit memblock allocations.
442 */
443 ppc64_rma_size = ULONG_MAX;
444 memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
445 } else
446 hash__early_init_devtree();
447}
448#endif /* CONFIG_PPC_BOOK3S_64 */