2 * Copyright IBM Corp. 2006
3 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
6 #include <linux/bootmem.h>
9 #include <linux/module.h>
10 #include <linux/list.h>
11 #include <linux/hugetlb.h>
12 #include <linux/slab.h>
13 #include <asm/pgalloc.h>
14 #include <asm/pgtable.h>
15 #include <asm/setup.h>
16 #include <asm/tlbflush.h>
17 #include <asm/sections.h>
19 static DEFINE_MUTEX(vmem_mutex);
21 struct memory_segment {
22 struct list_head list;
27 static LIST_HEAD(mem_segs);
29 static void __ref *vmem_alloc_pages(unsigned int order)
31 if (slab_is_available())
32 return (void *)__get_free_pages(GFP_KERNEL, order);
33 return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
36 static inline pud_t *vmem_pud_alloc(void)
41 pud = vmem_alloc_pages(2);
44 clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
49 static inline pmd_t *vmem_pmd_alloc(void)
54 pmd = vmem_alloc_pages(2);
57 clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
62 static pte_t __ref *vmem_pte_alloc(unsigned long address)
66 if (slab_is_available())
67 pte = (pte_t *) page_table_alloc(&init_mm, address);
69 pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t));
72 clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY,
73 PTRS_PER_PTE * sizeof(pte_t));
78 * Add a physical memory range to the 1:1 mapping.
80 static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
82 unsigned long end = start + size;
83 unsigned long address = start;
90 while (address < end) {
91 pg_dir = pgd_offset_k(address);
92 if (pgd_none(*pg_dir)) {
93 pu_dir = vmem_pud_alloc();
96 pgd_populate(&init_mm, pg_dir, pu_dir);
98 pu_dir = pud_offset(pg_dir, address);
99 #if defined(CONFIG_64BIT) && !defined(CONFIG_DEBUG_PAGEALLOC)
100 if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address &&
101 !(address & ~PUD_MASK) && (address + PUD_SIZE <= end)) {
102 pud_val(*pu_dir) = __pa(address) |
103 _REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE |
104 (ro ? _REGION_ENTRY_RO : 0);
109 if (pud_none(*pu_dir)) {
110 pm_dir = vmem_pmd_alloc();
113 pud_populate(&init_mm, pu_dir, pm_dir);
115 pm_dir = pmd_offset(pu_dir, address);
116 #if defined(CONFIG_64BIT) && !defined(CONFIG_DEBUG_PAGEALLOC)
117 if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
118 !(address & ~PMD_MASK) && (address + PMD_SIZE <= end)) {
119 pmd_val(*pm_dir) = __pa(address) |
120 _SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE |
121 (ro ? _SEGMENT_ENTRY_RO : 0);
126 if (pmd_none(*pm_dir)) {
127 pt_dir = vmem_pte_alloc(address);
130 pmd_populate(&init_mm, pm_dir, pt_dir);
133 pt_dir = pte_offset_kernel(pm_dir, address);
134 pte_val(*pt_dir) = __pa(address) | (ro ? _PAGE_RO : 0);
135 address += PAGE_SIZE;
139 flush_tlb_kernel_range(start, end);
144 * Remove a physical memory range from the 1:1 mapping.
145 * Currently only invalidates page table entries.
147 static void vmem_remove_range(unsigned long start, unsigned long size)
149 unsigned long end = start + size;
150 unsigned long address = start;
157 pte_val(pte) = _PAGE_TYPE_EMPTY;
158 while (address < end) {
159 pg_dir = pgd_offset_k(address);
160 if (pgd_none(*pg_dir)) {
161 address += PGDIR_SIZE;
164 pu_dir = pud_offset(pg_dir, address);
165 if (pud_none(*pu_dir)) {
169 if (pud_large(*pu_dir)) {
174 pm_dir = pmd_offset(pu_dir, address);
175 if (pmd_none(*pm_dir)) {
179 if (pmd_large(*pm_dir)) {
184 pt_dir = pte_offset_kernel(pm_dir, address);
186 address += PAGE_SIZE;
188 flush_tlb_kernel_range(start, end);
192 * Add a backed mem_map array to the virtual mem_map array.
194 int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
196 unsigned long address, start_addr, end_addr;
203 start_addr = (unsigned long) start;
204 end_addr = (unsigned long) (start + nr);
206 for (address = start_addr; address < end_addr;) {
207 pg_dir = pgd_offset_k(address);
208 if (pgd_none(*pg_dir)) {
209 pu_dir = vmem_pud_alloc();
212 pgd_populate(&init_mm, pg_dir, pu_dir);
215 pu_dir = pud_offset(pg_dir, address);
216 if (pud_none(*pu_dir)) {
217 pm_dir = vmem_pmd_alloc();
220 pud_populate(&init_mm, pu_dir, pm_dir);
223 pm_dir = pmd_offset(pu_dir, address);
224 if (pmd_none(*pm_dir)) {
226 /* Use 1MB frames for vmemmap if available. We always
227 * use large frames even if they are only partially
229 * Otherwise we would have also page tables since
230 * vmemmap_populate gets called for each section
232 if (MACHINE_HAS_EDAT1) {
235 new_page = vmemmap_alloc_block(PMD_SIZE, node);
238 pmd_val(*pm_dir) = __pa(new_page) |
239 _SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE;
240 address = (address + PMD_SIZE) & PMD_MASK;
244 pt_dir = vmem_pte_alloc(address);
247 pmd_populate(&init_mm, pm_dir, pt_dir);
248 } else if (pmd_large(*pm_dir)) {
249 address = (address + PMD_SIZE) & PMD_MASK;
253 pt_dir = pte_offset_kernel(pm_dir, address);
254 if (pte_none(*pt_dir)) {
255 unsigned long new_page;
257 new_page =__pa(vmem_alloc_pages(0));
260 pte_val(*pt_dir) = __pa(new_page);
262 address += PAGE_SIZE;
264 memset(start, 0, nr * sizeof(struct page));
267 flush_tlb_kernel_range(start_addr, end_addr);
271 void vmemmap_free(struct page *memmap, unsigned long nr_pages)
276 * Add memory segment to the segment list if it doesn't overlap with
277 * an already present segment.
279 static int insert_memory_segment(struct memory_segment *seg)
281 struct memory_segment *tmp;
283 if (seg->start + seg->size > VMEM_MAX_PHYS ||
284 seg->start + seg->size < seg->start)
287 list_for_each_entry(tmp, &mem_segs, list) {
288 if (seg->start >= tmp->start + tmp->size)
290 if (seg->start + seg->size <= tmp->start)
294 list_add(&seg->list, &mem_segs);
299 * Remove memory segment from the segment list.
301 static void remove_memory_segment(struct memory_segment *seg)
303 list_del(&seg->list);
306 static void __remove_shared_memory(struct memory_segment *seg)
308 remove_memory_segment(seg);
309 vmem_remove_range(seg->start, seg->size);
312 int vmem_remove_mapping(unsigned long start, unsigned long size)
314 struct memory_segment *seg;
317 mutex_lock(&vmem_mutex);
320 list_for_each_entry(seg, &mem_segs, list) {
321 if (seg->start == start && seg->size == size)
325 if (seg->start != start || seg->size != size)
329 __remove_shared_memory(seg);
332 mutex_unlock(&vmem_mutex);
336 int vmem_add_mapping(unsigned long start, unsigned long size)
338 struct memory_segment *seg;
341 mutex_lock(&vmem_mutex);
343 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
349 ret = insert_memory_segment(seg);
353 ret = vmem_add_mem(start, size, 0);
359 __remove_shared_memory(seg);
363 mutex_unlock(&vmem_mutex);
368 * map whole physical memory to virtual memory (identity mapping)
369 * we reserve enough space in the vmalloc area for vmemmap to hotplug
370 * additional memory segments.
372 void __init vmem_map_init(void)
374 unsigned long ro_start, ro_end;
375 unsigned long start, end;
378 ro_start = PFN_ALIGN((unsigned long)&_stext);
379 ro_end = (unsigned long)&_eshared & PAGE_MASK;
380 for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
381 if (memory_chunk[i].type == CHUNK_CRASHK ||
382 memory_chunk[i].type == CHUNK_OLDMEM)
384 start = memory_chunk[i].addr;
385 end = memory_chunk[i].addr + memory_chunk[i].size;
386 if (start >= ro_end || end <= ro_start)
387 vmem_add_mem(start, end - start, 0);
388 else if (start >= ro_start && end <= ro_end)
389 vmem_add_mem(start, end - start, 1);
390 else if (start >= ro_start) {
391 vmem_add_mem(start, ro_end - start, 1);
392 vmem_add_mem(ro_end, end - ro_end, 0);
393 } else if (end < ro_end) {
394 vmem_add_mem(start, ro_start - start, 0);
395 vmem_add_mem(ro_start, end - ro_start, 1);
397 vmem_add_mem(start, ro_start - start, 0);
398 vmem_add_mem(ro_start, ro_end - ro_start, 1);
399 vmem_add_mem(ro_end, end - ro_end, 0);
405 * Convert memory chunk array to a memory segment list so there is a single
406 * list that contains both r/w memory and shared memory segments.
408 static int __init vmem_convert_memory_chunk(void)
410 struct memory_segment *seg;
413 mutex_lock(&vmem_mutex);
414 for (i = 0; i < MEMORY_CHUNKS; i++) {
415 if (!memory_chunk[i].size)
417 if (memory_chunk[i].type == CHUNK_CRASHK ||
418 memory_chunk[i].type == CHUNK_OLDMEM)
420 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
422 panic("Out of memory...\n");
423 seg->start = memory_chunk[i].addr;
424 seg->size = memory_chunk[i].size;
425 insert_memory_segment(seg);
427 mutex_unlock(&vmem_mutex);
431 core_initcall(vmem_convert_memory_chunk);