2 * linux/arch/sh/mm/init.c
4 * Copyright (C) 1999 Niibe Yutaka
5 * Copyright (C) 2002 - 2007 Paul Mundt
7 * Based on linux/arch/i386/mm/init.c:
8 * Copyright (C) 1995 Linus Torvalds
11 #include <linux/swap.h>
12 #include <linux/init.h>
13 #include <linux/bootmem.h>
14 #include <linux/proc_fs.h>
15 #include <linux/pagemap.h>
16 #include <linux/percpu.h>
18 #include <asm/mmu_context.h>
20 #include <asm/cacheflush.h>
21 #include <asm/sections.h>
22 #include <asm/cache.h>
24 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
25 pgd_t swapper_pg_dir[PTRS_PER_PGD];
27 #ifdef CONFIG_SUPERH32
29 * Handle trivial transitions between cached and uncached
30 * segments, making use of the 1:1 mapping relationship in
33 * This is the offset of the uncached section from its cached alias.
34 * Default value only valid in 29 bit mode, in 32bit mode will be
35 * overridden in pmb_init.
37 unsigned long cached_to_uncached = P2SEG - P1SEG;
41 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
48 pgd = pgd_offset_k(addr);
54 pud = pud_alloc(NULL, pgd, addr);
60 pmd = pmd_alloc(NULL, pud, addr);
66 pte = pte_offset_kernel(pmd, addr);
67 if (!pte_none(*pte)) {
72 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
73 local_flush_tlb_one(get_asid(), addr);
77 * As a performance optimization, other platforms preserve the fixmap mapping
78 * across a context switch, we don't presently do this, but this could be done
79 * in a similar fashion as to the wired TLB interface that sh64 uses (by way
80 * of the memory mapped UTLB configuration) -- this unfortunately forces us to
81 * give up a TLB entry for each mapping we want to preserve. While this may be
82 * viable for a small number of fixmaps, it's not particularly useful for
83 * everything and needs to be carefully evaluated. (ie, we may want this for
86 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
87 * in at __set_fixmap() time to determine the appropriate behavior to follow.
91 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
93 unsigned long address = __fix_to_virt(idx);
95 if (idx >= __end_of_fixed_addresses) {
100 set_pte_phys(address, phys, prot);
103 void __init page_table_range_init(unsigned long start, unsigned long end,
114 i = __pgd_offset(vaddr);
115 j = __pud_offset(vaddr);
116 k = __pmd_offset(vaddr);
119 for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
121 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
123 for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
124 if (pmd_none(*pmd)) {
125 pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
126 pmd_populate_kernel(&init_mm, pmd, pte);
127 BUG_ON(pte != pte_offset_kernel(pmd, 0));
136 #endif /* CONFIG_MMU */
139 * paging_init() sets up the page tables
141 void __init paging_init(void)
143 unsigned long max_zone_pfns[MAX_NR_ZONES];
144 unsigned long vaddr, end;
147 /* We don't need to map the kernel through the TLB, as
148 * it is permanatly mapped using P1. So clear the
150 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
152 /* Set an initial value for the MMU.TTB so we don't have to
153 * check for a null value. */
154 set_TTB(swapper_pg_dir);
157 * Populate the relevant portions of swapper_pg_dir so that
158 * we can use the fixmap entries without calling kmalloc.
159 * pte's will be filled in by __set_fixmap().
161 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
162 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
163 page_table_range_init(vaddr, end, swapper_pg_dir);
165 kmap_coherent_init();
167 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
169 for_each_online_node(nid) {
170 pg_data_t *pgdat = NODE_DATA(nid);
171 unsigned long low, start_pfn;
173 start_pfn = pgdat->bdata->node_min_pfn;
174 low = pgdat->bdata->node_low_pfn;
176 if (max_zone_pfns[ZONE_NORMAL] < low)
177 max_zone_pfns[ZONE_NORMAL] = low;
179 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
180 nid, start_pfn, low);
183 free_area_init_nodes(max_zone_pfns);
185 /* Set up the uncached fixmap */
186 set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
189 static struct kcore_list kcore_mem, kcore_vmalloc;
191 void __init mem_init(void)
193 int codesize, datasize, initsize;
199 for_each_online_node(nid) {
200 pg_data_t *pgdat = NODE_DATA(nid);
201 unsigned long node_pages = 0;
202 void *node_high_memory;
204 num_physpages += pgdat->node_present_pages;
206 if (pgdat->node_spanned_pages)
207 node_pages = free_all_bootmem_node(pgdat);
209 totalram_pages += node_pages;
211 node_high_memory = (void *)__va((pgdat->node_start_pfn +
212 pgdat->node_spanned_pages) <<
214 if (node_high_memory > high_memory)
215 high_memory = node_high_memory;
218 /* Set this up early, so we can take care of the zero page */
221 /* clear the zero-page */
222 memset(empty_zero_page, 0, PAGE_SIZE);
223 __flush_wback_region(empty_zero_page, PAGE_SIZE);
225 codesize = (unsigned long) &_etext - (unsigned long) &_text;
226 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
227 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
229 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
230 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
231 VMALLOC_END - VMALLOC_START);
233 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
234 "%dk data, %dk init)\n",
235 nr_free_pages() << (PAGE_SHIFT-10),
236 num_physpages << (PAGE_SHIFT-10),
241 /* Initialize the vDSO */
245 void free_initmem(void)
249 addr = (unsigned long)(&__init_begin);
250 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
251 ClearPageReserved(virt_to_page(addr));
252 init_page_count(virt_to_page(addr));
256 printk("Freeing unused kernel memory: %ldk freed\n",
257 ((unsigned long)&__init_end -
258 (unsigned long)&__init_begin) >> 10);
261 #ifdef CONFIG_BLK_DEV_INITRD
262 void free_initrd_mem(unsigned long start, unsigned long end)
265 for (p = start; p < end; p += PAGE_SIZE) {
266 ClearPageReserved(virt_to_page(p));
267 init_page_count(virt_to_page(p));
271 printk("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
275 #if THREAD_SHIFT < PAGE_SHIFT
276 static struct kmem_cache *thread_info_cache;
278 struct thread_info *alloc_thread_info(struct task_struct *tsk)
280 struct thread_info *ti;
282 ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL);
283 if (unlikely(ti == NULL))
285 #ifdef CONFIG_DEBUG_STACK_USAGE
286 memset(ti, 0, THREAD_SIZE);
291 void free_thread_info(struct thread_info *ti)
293 kmem_cache_free(thread_info_cache, ti);
296 void thread_info_cache_init(void)
298 thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
299 THREAD_SIZE, 0, NULL);
300 BUG_ON(thread_info_cache == NULL);
302 #endif /* THREAD_SHIFT < PAGE_SHIFT */
304 #ifdef CONFIG_MEMORY_HOTPLUG
305 int arch_add_memory(int nid, u64 start, u64 size)
308 unsigned long start_pfn = start >> PAGE_SHIFT;
309 unsigned long nr_pages = size >> PAGE_SHIFT;
312 pgdat = NODE_DATA(nid);
314 /* We only have ZONE_NORMAL, so this is easy.. */
315 ret = __add_pages(nid, pgdat->node_zones + ZONE_NORMAL,
316 start_pfn, nr_pages);
318 printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
322 EXPORT_SYMBOL_GPL(arch_add_memory);
325 int memory_add_physaddr_to_nid(u64 addr)
327 /* Node 0 for now.. */
330 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
332 #endif /* CONFIG_MEMORY_HOTPLUG */