4 * Copyright IBM Corp. 2006
5 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
8 #include <linux/bootmem.h>
11 #include <linux/module.h>
12 #include <linux/list.h>
13 #include <linux/hugetlb.h>
14 #include <linux/slab.h>
15 #include <asm/pgalloc.h>
16 #include <asm/pgtable.h>
17 #include <asm/setup.h>
18 #include <asm/tlbflush.h>
19 #include <asm/sections.h>
21 static DEFINE_MUTEX(vmem_mutex);
23 struct memory_segment {
24 struct list_head list;
29 static LIST_HEAD(mem_segs);
31 static void __ref *vmem_alloc_pages(unsigned int order)
33 if (slab_is_available())
34 return (void *)__get_free_pages(GFP_KERNEL, order);
35 return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
38 static inline pud_t *vmem_pud_alloc(void)
43 pud = vmem_alloc_pages(2);
46 clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
51 static inline pmd_t *vmem_pmd_alloc(void)
56 pmd = vmem_alloc_pages(2);
59 clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
64 static pte_t __ref *vmem_pte_alloc(unsigned long address)
68 if (slab_is_available())
69 pte = (pte_t *) page_table_alloc(&init_mm, address);
71 pte = alloc_bootmem(PTRS_PER_PTE * sizeof(pte_t));
74 clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY,
75 PTRS_PER_PTE * sizeof(pte_t));
80 * Add a physical memory range to the 1:1 mapping.
82 static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
84 unsigned long address;
92 for (address = start; address < start + size; address += PAGE_SIZE) {
93 pg_dir = pgd_offset_k(address);
94 if (pgd_none(*pg_dir)) {
95 pu_dir = vmem_pud_alloc();
98 pgd_populate(&init_mm, pg_dir, pu_dir);
101 pu_dir = pud_offset(pg_dir, address);
102 if (pud_none(*pu_dir)) {
103 pm_dir = vmem_pmd_alloc();
106 pud_populate(&init_mm, pu_dir, pm_dir);
109 pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
110 pm_dir = pmd_offset(pu_dir, address);
113 if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
114 (address + HPAGE_SIZE <= start + size) &&
115 (address >= HPAGE_SIZE)) {
116 pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
117 pmd_val(*pm_dir) = pte_val(pte);
118 address += HPAGE_SIZE - PAGE_SIZE;
122 if (pmd_none(*pm_dir)) {
123 pt_dir = vmem_pte_alloc(address);
126 pmd_populate(&init_mm, pm_dir, pt_dir);
129 pt_dir = pte_offset_kernel(pm_dir, address);
134 flush_tlb_kernel_range(start, start + size);
139 * Remove a physical memory range from the 1:1 mapping.
140 * Currently only invalidates page table entries.
142 static void vmem_remove_range(unsigned long start, unsigned long size)
144 unsigned long address;
151 pte_val(pte) = _PAGE_TYPE_EMPTY;
152 for (address = start; address < start + size; address += PAGE_SIZE) {
153 pg_dir = pgd_offset_k(address);
154 pu_dir = pud_offset(pg_dir, address);
155 if (pud_none(*pu_dir))
157 pm_dir = pmd_offset(pu_dir, address);
158 if (pmd_none(*pm_dir))
161 if (pmd_huge(*pm_dir)) {
163 address += HPAGE_SIZE - PAGE_SIZE;
167 pt_dir = pte_offset_kernel(pm_dir, address);
170 flush_tlb_kernel_range(start, start + size);
174 * Add a backed mem_map array to the virtual mem_map array.
176 int __meminit vmemmap_populate(struct page *start, unsigned long nr, int node)
178 unsigned long address, start_addr, end_addr;
186 start_addr = (unsigned long) start;
187 end_addr = (unsigned long) (start + nr);
189 for (address = start_addr; address < end_addr; address += PAGE_SIZE) {
190 pg_dir = pgd_offset_k(address);
191 if (pgd_none(*pg_dir)) {
192 pu_dir = vmem_pud_alloc();
195 pgd_populate(&init_mm, pg_dir, pu_dir);
198 pu_dir = pud_offset(pg_dir, address);
199 if (pud_none(*pu_dir)) {
200 pm_dir = vmem_pmd_alloc();
203 pud_populate(&init_mm, pu_dir, pm_dir);
206 pm_dir = pmd_offset(pu_dir, address);
207 if (pmd_none(*pm_dir)) {
208 pt_dir = vmem_pte_alloc(address);
211 pmd_populate(&init_mm, pm_dir, pt_dir);
214 pt_dir = pte_offset_kernel(pm_dir, address);
215 if (pte_none(*pt_dir)) {
216 unsigned long new_page;
218 new_page =__pa(vmem_alloc_pages(0));
221 pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
225 memset(start, 0, nr * sizeof(struct page));
228 flush_tlb_kernel_range(start_addr, end_addr);
233 * Add memory segment to the segment list if it doesn't overlap with
234 * an already present segment.
236 static int insert_memory_segment(struct memory_segment *seg)
238 struct memory_segment *tmp;
240 if (seg->start + seg->size > VMEM_MAX_PHYS ||
241 seg->start + seg->size < seg->start)
244 list_for_each_entry(tmp, &mem_segs, list) {
245 if (seg->start >= tmp->start + tmp->size)
247 if (seg->start + seg->size <= tmp->start)
251 list_add(&seg->list, &mem_segs);
256 * Remove memory segment from the segment list.
258 static void remove_memory_segment(struct memory_segment *seg)
260 list_del(&seg->list);
263 static void __remove_shared_memory(struct memory_segment *seg)
265 remove_memory_segment(seg);
266 vmem_remove_range(seg->start, seg->size);
269 int vmem_remove_mapping(unsigned long start, unsigned long size)
271 struct memory_segment *seg;
274 mutex_lock(&vmem_mutex);
277 list_for_each_entry(seg, &mem_segs, list) {
278 if (seg->start == start && seg->size == size)
282 if (seg->start != start || seg->size != size)
286 __remove_shared_memory(seg);
289 mutex_unlock(&vmem_mutex);
293 int vmem_add_mapping(unsigned long start, unsigned long size)
295 struct memory_segment *seg;
298 mutex_lock(&vmem_mutex);
300 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
306 ret = insert_memory_segment(seg);
310 ret = vmem_add_mem(start, size, 0);
316 __remove_shared_memory(seg);
320 mutex_unlock(&vmem_mutex);
325 * map whole physical memory to virtual memory (identity mapping)
326 * we reserve enough space in the vmalloc area for vmemmap to hotplug
327 * additional memory segments.
329 void __init vmem_map_init(void)
331 unsigned long ro_start, ro_end;
332 unsigned long start, end;
335 ro_start = ((unsigned long)&_stext) & PAGE_MASK;
336 ro_end = PFN_ALIGN((unsigned long)&_eshared);
337 for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
338 if (memory_chunk[i].type == CHUNK_CRASHK ||
339 memory_chunk[i].type == CHUNK_OLDMEM)
341 start = memory_chunk[i].addr;
342 end = memory_chunk[i].addr + memory_chunk[i].size;
343 if (start >= ro_end || end <= ro_start)
344 vmem_add_mem(start, end - start, 0);
345 else if (start >= ro_start && end <= ro_end)
346 vmem_add_mem(start, end - start, 1);
347 else if (start >= ro_start) {
348 vmem_add_mem(start, ro_end - start, 1);
349 vmem_add_mem(ro_end, end - ro_end, 0);
350 } else if (end < ro_end) {
351 vmem_add_mem(start, ro_start - start, 0);
352 vmem_add_mem(ro_start, end - ro_start, 1);
354 vmem_add_mem(start, ro_start - start, 0);
355 vmem_add_mem(ro_start, ro_end - ro_start, 1);
356 vmem_add_mem(ro_end, end - ro_end, 0);
362 * Convert memory chunk array to a memory segment list so there is a single
363 * list that contains both r/w memory and shared memory segments.
365 static int __init vmem_convert_memory_chunk(void)
367 struct memory_segment *seg;
370 mutex_lock(&vmem_mutex);
371 for (i = 0; i < MEMORY_CHUNKS; i++) {
372 if (!memory_chunk[i].size)
374 if (memory_chunk[i].type == CHUNK_CRASHK ||
375 memory_chunk[i].type == CHUNK_OLDMEM)
377 seg = kzalloc(sizeof(*seg), GFP_KERNEL);
379 panic("Out of memory...\n");
380 seg->start = memory_chunk[i].addr;
381 seg->size = memory_chunk[i].size;
382 insert_memory_segment(seg);
384 mutex_unlock(&vmem_mutex);
388 core_initcall(vmem_convert_memory_chunk);