3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
6 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
7 * Copyright (C) 1996 Paul Mackerras
9 * Derived from "arch/i386/mm/init.c"
10 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
12 * Dave Engebretsen <engebret@us.ibm.com>
13 * Rework for PPC64 port.
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
24 #include <linux/signal.h>
25 #include <linux/sched.h>
26 #include <linux/kernel.h>
27 #include <linux/errno.h>
28 #include <linux/string.h>
29 #include <linux/types.h>
30 #include <linux/mman.h>
32 #include <linux/swap.h>
33 #include <linux/stddef.h>
34 #include <linux/vmalloc.h>
35 #include <linux/init.h>
36 #include <linux/delay.h>
37 #include <linux/highmem.h>
38 #include <linux/idr.h>
39 #include <linux/nodemask.h>
40 #include <linux/module.h>
41 #include <linux/poison.h>
42 #include <linux/memblock.h>
43 #include <linux/hugetlb.h>
44 #include <linux/slab.h>
46 #include <asm/pgalloc.h>
51 #include <asm/mmu_context.h>
52 #include <asm/pgtable.h>
54 #include <asm/uaccess.h>
56 #include <asm/machdep.h>
59 #include <asm/processor.h>
60 #include <asm/mmzone.h>
61 #include <asm/cputable.h>
62 #include <asm/sections.h>
63 #include <asm/iommu.h>
68 #ifdef CONFIG_PPC_STD_MMU_64
69 #if H_PGTABLE_RANGE > USER_VSID_RANGE
70 #warning Limited user VSID range means pagetable space is wasted
73 #if (TASK_SIZE_USER64 < H_PGTABLE_RANGE) && (TASK_SIZE_USER64 < USER_VSID_RANGE)
74 #warning TASK_SIZE is smaller than it needs to be.
76 #endif /* CONFIG_PPC_STD_MMU_64 */
78 phys_addr_t memstart_addr
= ~0;
79 EXPORT_SYMBOL_GPL(memstart_addr
);
80 phys_addr_t kernstart_addr
;
81 EXPORT_SYMBOL_GPL(kernstart_addr
);
83 static void pgd_ctor(void *addr
)
85 memset(addr
, 0, PGD_TABLE_SIZE
);
88 static void pud_ctor(void *addr
)
90 memset(addr
, 0, PUD_TABLE_SIZE
);
93 static void pmd_ctor(void *addr
)
95 memset(addr
, 0, PMD_TABLE_SIZE
);
98 struct kmem_cache
*pgtable_cache
[MAX_PGTABLE_INDEX_SIZE
];
101 * Create a kmem_cache() for pagetables. This is not used for PTE
102 * pages - they're linked to struct page, come from the normal free
103 * pages pool and have a different entry size (see real_pte_t) to
104 * everything else. Caches created by this function are used for all
105 * the higher level pagetables, and for hugepage pagetables.
107 void pgtable_cache_add(unsigned shift
, void (*ctor
)(void *))
110 unsigned long table_size
= sizeof(void *) << shift
;
111 unsigned long align
= table_size
;
113 /* When batching pgtable pointers for RCU freeing, we store
114 * the index size in the low bits. Table alignment must be
115 * big enough to fit it.
117 * Likewise, hugeapge pagetable pointers contain a (different)
118 * shift value in the low bits. All tables must be aligned so
119 * as to leave enough 0 bits in the address to contain it. */
120 unsigned long minalign
= max(MAX_PGTABLE_INDEX_SIZE
+ 1,
121 HUGEPD_SHIFT_MASK
+ 1);
122 struct kmem_cache
*new;
124 /* It would be nice if this was a BUILD_BUG_ON(), but at the
125 * moment, gcc doesn't seem to recognize is_power_of_2 as a
126 * constant expression, so so much for that. */
127 BUG_ON(!is_power_of_2(minalign
));
128 BUG_ON((shift
< 1) || (shift
> MAX_PGTABLE_INDEX_SIZE
));
130 if (PGT_CACHE(shift
))
131 return; /* Already have a cache of this size */
133 align
= max_t(unsigned long, align
, minalign
);
134 name
= kasprintf(GFP_KERNEL
, "pgtable-2^%d", shift
);
135 new = kmem_cache_create(name
, table_size
, align
, 0, ctor
);
137 pgtable_cache
[shift
- 1] = new;
138 pr_debug("Allocated pgtable cache for order %d\n", shift
);
142 void pgtable_cache_init(void)
144 pgtable_cache_add(PGD_INDEX_SIZE
, pgd_ctor
);
145 pgtable_cache_add(PMD_CACHE_INDEX
, pmd_ctor
);
147 * In all current configs, when the PUD index exists it's the
148 * same size as either the pgd or pmd index except with THP enabled
151 if (PUD_INDEX_SIZE
&& !PGT_CACHE(PUD_INDEX_SIZE
))
152 pgtable_cache_add(PUD_INDEX_SIZE
, pud_ctor
);
154 if (!PGT_CACHE(PGD_INDEX_SIZE
) || !PGT_CACHE(PMD_CACHE_INDEX
))
155 panic("Couldn't allocate pgtable caches");
156 if (PUD_INDEX_SIZE
&& !PGT_CACHE(PUD_INDEX_SIZE
))
157 panic("Couldn't allocate pud pgtable caches");
160 #ifdef CONFIG_SPARSEMEM_VMEMMAP
162 * Given an address within the vmemmap, determine the pfn of the page that
163 * represents the start of the section it is within. Note that we have to
164 * do this by hand as the proffered address may not be correctly aligned.
165 * Subtraction of non-aligned pointers produces undefined results.
167 static unsigned long __meminit
vmemmap_section_start(unsigned long page
)
169 unsigned long offset
= page
- ((unsigned long)(vmemmap
));
171 /* Return the pfn of the start of the section. */
172 return (offset
/ sizeof(struct page
)) & PAGE_SECTION_MASK
;
176 * Check if this vmemmap page is already initialised. If any section
177 * which overlaps this vmemmap page is initialised then this page is
178 * initialised already.
180 static int __meminit
vmemmap_populated(unsigned long start
, int page_size
)
182 unsigned long end
= start
+ page_size
;
183 start
= (unsigned long)(pfn_to_page(vmemmap_section_start(start
)));
185 for (; start
< end
; start
+= (PAGES_PER_SECTION
* sizeof(struct page
)))
186 if (pfn_valid(page_to_pfn((struct page
*)start
)))
192 struct vmemmap_backing
*vmemmap_list
;
193 static struct vmemmap_backing
*next
;
195 static int num_freed
;
197 static __meminit
struct vmemmap_backing
* vmemmap_list_alloc(int node
)
199 struct vmemmap_backing
*vmem_back
;
200 /* get from freed entries first */
209 /* allocate a page when required and hand out chunks */
211 next
= vmemmap_alloc_block(PAGE_SIZE
, node
);
212 if (unlikely(!next
)) {
216 num_left
= PAGE_SIZE
/ sizeof(struct vmemmap_backing
);
224 static __meminit
void vmemmap_list_populate(unsigned long phys
,
228 struct vmemmap_backing
*vmem_back
;
230 vmem_back
= vmemmap_list_alloc(node
);
231 if (unlikely(!vmem_back
)) {
236 vmem_back
->phys
= phys
;
237 vmem_back
->virt_addr
= start
;
238 vmem_back
->list
= vmemmap_list
;
240 vmemmap_list
= vmem_back
;
243 int __meminit
vmemmap_populate(unsigned long start
, unsigned long end
, int node
)
245 unsigned long page_size
= 1 << mmu_psize_defs
[mmu_vmemmap_psize
].shift
;
247 /* Align to the page size of the linear mapping. */
248 start
= _ALIGN_DOWN(start
, page_size
);
250 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start
, end
, node
);
252 for (; start
< end
; start
+= page_size
) {
256 if (vmemmap_populated(start
, page_size
))
259 p
= vmemmap_alloc_block(page_size
, node
);
263 vmemmap_list_populate(__pa(p
), start
, node
);
265 pr_debug(" * %016lx..%016lx allocated at %p\n",
266 start
, start
+ page_size
, p
);
268 rc
= vmemmap_create_mapping(start
, page_size
, __pa(p
));
271 "vmemmap_populate: Unable to create vmemmap mapping: %d\n",
280 #ifdef CONFIG_MEMORY_HOTPLUG
281 static unsigned long vmemmap_list_free(unsigned long start
)
283 struct vmemmap_backing
*vmem_back
, *vmem_back_prev
;
285 vmem_back_prev
= vmem_back
= vmemmap_list
;
287 /* look for it with prev pointer recorded */
288 for (; vmem_back
; vmem_back
= vmem_back
->list
) {
289 if (vmem_back
->virt_addr
== start
)
291 vmem_back_prev
= vmem_back
;
294 if (unlikely(!vmem_back
)) {
299 /* remove it from vmemmap_list */
300 if (vmem_back
== vmemmap_list
) /* remove head */
301 vmemmap_list
= vmem_back
->list
;
303 vmem_back_prev
->list
= vmem_back
->list
;
305 /* next point to this freed entry */
306 vmem_back
->list
= next
;
310 return vmem_back
->phys
;
313 void __ref
vmemmap_free(unsigned long start
, unsigned long end
)
315 unsigned long page_size
= 1 << mmu_psize_defs
[mmu_vmemmap_psize
].shift
;
317 start
= _ALIGN_DOWN(start
, page_size
);
319 pr_debug("vmemmap_free %lx...%lx\n", start
, end
);
321 for (; start
< end
; start
+= page_size
) {
325 * the section has already be marked as invalid, so
326 * vmemmap_populated() true means some other sections still
327 * in this page, so skip it.
329 if (vmemmap_populated(start
, page_size
))
332 addr
= vmemmap_list_free(start
);
334 struct page
*page
= pfn_to_page(addr
>> PAGE_SHIFT
);
336 if (PageReserved(page
)) {
337 /* allocated from bootmem */
338 if (page_size
< PAGE_SIZE
) {
340 * this shouldn't happen, but if it is
341 * the case, leave the memory there
345 unsigned int nr_pages
=
346 1 << get_order(page_size
);
348 free_reserved_page(page
++);
351 free_pages((unsigned long)(__va(addr
)),
352 get_order(page_size
));
354 vmemmap_remove_mapping(start
, page_size
);
359 void register_page_bootmem_memmap(unsigned long section_nr
,
360 struct page
*start_page
, unsigned long size
)
365 * We do not have access to the sparsemem vmemmap, so we fallback to
366 * walking the list of sparsemem blocks which we already maintain for
367 * the sake of crashdump. In the long run, we might want to maintain
368 * a tree if performance of that linear walk becomes a problem.
370 * realmode_pfn_to_page functions can fail due to:
371 * 1) As real sparsemem blocks do not lay in RAM continously (they
372 * are in virtual address space which is not available in the real mode),
373 * the requested page struct can be split between blocks so get_page/put_page
375 * 2) When huge pages are used, the get_page/put_page API will fail
376 * in real mode as the linked addresses in the page struct are virtual
379 struct page
*realmode_pfn_to_page(unsigned long pfn
)
381 struct vmemmap_backing
*vmem_back
;
383 unsigned long page_size
= 1 << mmu_psize_defs
[mmu_vmemmap_psize
].shift
;
384 unsigned long pg_va
= (unsigned long) pfn_to_page(pfn
);
386 for (vmem_back
= vmemmap_list
; vmem_back
; vmem_back
= vmem_back
->list
) {
387 if (pg_va
< vmem_back
->virt_addr
)
390 /* After vmemmap_list entry free is possible, need check all */
391 if ((pg_va
+ sizeof(struct page
)) <=
392 (vmem_back
->virt_addr
+ page_size
)) {
393 page
= (struct page
*) (vmem_back
->phys
+ pg_va
-
394 vmem_back
->virt_addr
);
399 /* Probably that page struct is split between real pages */
402 EXPORT_SYMBOL_GPL(realmode_pfn_to_page
);
404 #elif defined(CONFIG_FLATMEM)
406 struct page
*realmode_pfn_to_page(unsigned long pfn
)
408 struct page
*page
= pfn_to_page(pfn
);
411 EXPORT_SYMBOL_GPL(realmode_pfn_to_page
);
413 #endif /* CONFIG_SPARSEMEM_VMEMMAP/CONFIG_FLATMEM */
415 #ifdef CONFIG_PPC_STD_MMU_64
416 static bool disable_radix
;
417 static int __init
parse_disable_radix(char *p
)
419 disable_radix
= true;
422 early_param("disable_radix", parse_disable_radix
);
424 void __init
mmu_early_init_devtree(void)
426 /* Disable radix mode based on kernel command line. */
428 cur_cpu_spec
->mmu_features
&= ~MMU_FTR_TYPE_RADIX
;
431 radix__early_init_devtree();
433 hash__early_init_devtree();
435 #endif /* CONFIG_PPC_STD_MMU_64 */