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(unsigned long start, unsigned long end, int node)
196 unsigned long address = start;
203 for (address = start; address < end;) {
204 pg_dir = pgd_offset_k(address);
205 if (pgd_none(*pg_dir)) {
206 pu_dir = vmem_pud_alloc();
209 pgd_populate(&init_mm, pg_dir, pu_dir);
212 pu_dir = pud_offset(pg_dir, address);
213 if (pud_none(*pu_dir)) {
214 pm_dir = vmem_pmd_alloc();
217 pud_populate(&init_mm, pu_dir, pm_dir);
220 pm_dir = pmd_offset(pu_dir, address);
221 if (pmd_none(*pm_dir)) {
223 /* Use 1MB frames for vmemmap if available. We always
224 * use large frames even if they are only partially
226 * Otherwise we would have also page tables since
227 * vmemmap_populate gets called for each section
229 if (MACHINE_HAS_EDAT1) {
232 new_page = vmemmap_alloc_block(PMD_SIZE, node);
235 pmd_val(*pm_dir) = __pa(new_page) |
236 _SEGMENT_ENTRY | _SEGMENT_ENTRY_LARGE |
238 address = (address + PMD_SIZE) & PMD_MASK;
242 pt_dir = vmem_pte_alloc(address);
245 pmd_populate(&init_mm, pm_dir, pt_dir);
246 } else if (pmd_large(*pm_dir)) {
247 address = (address + PMD_SIZE) & PMD_MASK;
251 pt_dir = pte_offset_kernel(pm_dir, address);
252 if (pte_none(*pt_dir)) {
253 unsigned long new_page;
255 new_page =__pa(vmem_alloc_pages(0));
258 pte_val(*pt_dir) = __pa(new_page);
260 address += PAGE_SIZE;
262 memset((void *)start, 0, end - start);
265 flush_tlb_kernel_range(start, end);
269 void vmemmap_free(unsigned long start, unsigned long end)
274 * Add memory segment to the segment list if it doesn't overlap with
275 * an already present segment.
277 static int insert_memory_segment(struct memory_segment *seg)
279 struct memory_segment *tmp;
281 if (seg->start + seg->size > VMEM_MAX_PHYS ||
282 seg->start + seg->size < seg->start)
285 list_for_each_entry(tmp, &mem_segs, list) {
286 if (seg->start >= tmp->start + tmp->size)
288 if (seg->start + seg->size <= tmp->start)
292 list_add(&seg->list, &mem_segs);
297 * Remove memory segment from the segment list.
299 static void remove_memory_segment(struct memory_segment *seg)
301 list_del(&seg->list);
304 static void __remove_shared_memory(struct memory_segment *seg)
306 remove_memory_segment(seg);
307 vmem_remove_range(seg->start, seg->size);
310 int vmem_remove_mapping(unsigned long start, unsigned long size)
312 struct memory_segment *seg;
315 mutex_lock(&vmem_mutex);
318 list_for_each_entry(seg, &mem_segs, list) {
319 if (seg->start == start && seg->size == size)
323 if (seg->start != start || seg->size != size)
327 __remove_shared_memory(seg);
330 mutex_unlock(&vmem_mutex);
334 int vmem_add_mapping(unsigned long start, unsigned long size)
336 struct memory_segment *seg;
339 mutex_lock(&vmem_mutex);
341 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
347 ret = insert_memory_segment(seg);
351 ret = vmem_add_mem(start, size, 0);
357 __remove_shared_memory(seg);
361 mutex_unlock(&vmem_mutex);
366 * map whole physical memory to virtual memory (identity mapping)
367 * we reserve enough space in the vmalloc area for vmemmap to hotplug
368 * additional memory segments.
370 void __init vmem_map_init(void)
372 unsigned long ro_start, ro_end;
373 unsigned long start, end;
376 ro_start = PFN_ALIGN((unsigned long)&_stext);
377 ro_end = (unsigned long)&_eshared & PAGE_MASK;
378 for (i = 0; i < MEMORY_CHUNKS; i++) {
379 if (!memory_chunk[i].size)
381 start = memory_chunk[i].addr;
382 end = memory_chunk[i].addr + memory_chunk[i].size;
383 if (start >= ro_end || end <= ro_start)
384 vmem_add_mem(start, end - start, 0);
385 else if (start >= ro_start && end <= ro_end)
386 vmem_add_mem(start, end - start, 1);
387 else if (start >= ro_start) {
388 vmem_add_mem(start, ro_end - start, 1);
389 vmem_add_mem(ro_end, end - ro_end, 0);
390 } else if (end < ro_end) {
391 vmem_add_mem(start, ro_start - start, 0);
392 vmem_add_mem(ro_start, end - ro_start, 1);
394 vmem_add_mem(start, ro_start - start, 0);
395 vmem_add_mem(ro_start, ro_end - ro_start, 1);
396 vmem_add_mem(ro_end, end - ro_end, 0);
402 * Convert memory chunk array to a memory segment list so there is a single
403 * list that contains both r/w memory and shared memory segments.
405 static int __init vmem_convert_memory_chunk(void)
407 struct memory_segment *seg;
410 mutex_lock(&vmem_mutex);
411 for (i = 0; i < MEMORY_CHUNKS; i++) {
412 if (!memory_chunk[i].size)
414 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
416 panic("Out of memory...\n");
417 seg->start = memory_chunk[i].addr;
418 seg->size = memory_chunk[i].size;
419 insert_memory_segment(seg);
421 mutex_unlock(&vmem_mutex);
425 core_initcall(vmem_convert_memory_chunk);