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 <linux/dma-mapping.h>
19 #include <asm/mmu_context.h>
21 #include <asm/cacheflush.h>
22 #include <asm/sections.h>
23 #include <asm/cache.h>
25 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
26 pgd_t swapper_pg_dir[PTRS_PER_PGD];
28 #ifdef CONFIG_SUPERH32
30 * Handle trivial transitions between cached and uncached
31 * segments, making use of the 1:1 mapping relationship in
34 * This is the offset of the uncached section from its cached alias.
35 * Default value only valid in 29 bit mode, in 32bit mode will be
36 * overridden in pmb_init.
38 unsigned long cached_to_uncached = P2SEG - P1SEG;
42 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
49 pgd = pgd_offset_k(addr);
55 pud = pud_alloc(NULL, pgd, addr);
61 pmd = pmd_alloc(NULL, pud, addr);
67 pte = pte_offset_kernel(pmd, addr);
68 if (!pte_none(*pte)) {
73 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
74 local_flush_tlb_one(get_asid(), addr);
78 * As a performance optimization, other platforms preserve the fixmap mapping
79 * across a context switch, we don't presently do this, but this could be done
80 * in a similar fashion as to the wired TLB interface that sh64 uses (by way
81 * of the memory mapped UTLB configuration) -- this unfortunately forces us to
82 * give up a TLB entry for each mapping we want to preserve. While this may be
83 * viable for a small number of fixmaps, it's not particularly useful for
84 * everything and needs to be carefully evaluated. (ie, we may want this for
87 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
88 * in at __set_fixmap() time to determine the appropriate behavior to follow.
92 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
94 unsigned long address = __fix_to_virt(idx);
96 if (idx >= __end_of_fixed_addresses) {
101 set_pte_phys(address, phys, prot);
104 void __init page_table_range_init(unsigned long start, unsigned long end,
115 i = __pgd_offset(vaddr);
116 j = __pud_offset(vaddr);
117 k = __pmd_offset(vaddr);
120 for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
122 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
123 #ifdef __PAGETABLE_PMD_FOLDED
126 pmd = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
127 pud_populate(&init_mm, pud, pmd);
130 for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
131 if (pmd_none(*pmd)) {
132 pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
133 pmd_populate_kernel(&init_mm, pmd, pte);
134 BUG_ON(pte != pte_offset_kernel(pmd, 0));
143 #endif /* CONFIG_MMU */
146 * paging_init() sets up the page tables
148 void __init paging_init(void)
150 unsigned long max_zone_pfns[MAX_NR_ZONES];
151 unsigned long vaddr, end;
154 /* We don't need to map the kernel through the TLB, as
155 * it is permanatly mapped using P1. So clear the
157 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
159 /* Set an initial value for the MMU.TTB so we don't have to
160 * check for a null value. */
161 set_TTB(swapper_pg_dir);
164 * Populate the relevant portions of swapper_pg_dir so that
165 * we can use the fixmap entries without calling kmalloc.
166 * pte's will be filled in by __set_fixmap().
168 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
169 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
170 page_table_range_init(vaddr, end, swapper_pg_dir);
172 kmap_coherent_init();
174 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
176 for_each_online_node(nid) {
177 pg_data_t *pgdat = NODE_DATA(nid);
178 unsigned long low, start_pfn;
180 start_pfn = pgdat->bdata->node_min_pfn;
181 low = pgdat->bdata->node_low_pfn;
183 if (max_zone_pfns[ZONE_NORMAL] < low)
184 max_zone_pfns[ZONE_NORMAL] = low;
186 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
187 nid, start_pfn, low);
190 free_area_init_nodes(max_zone_pfns);
192 /* Set up the uncached fixmap */
193 set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
197 * Early initialization for any I/O MMUs we might have.
199 static void __init iommu_init(void)
204 void __init mem_init(void)
206 int codesize, datasize, initsize;
214 for_each_online_node(nid) {
215 pg_data_t *pgdat = NODE_DATA(nid);
216 unsigned long node_pages = 0;
217 void *node_high_memory;
219 num_physpages += pgdat->node_present_pages;
221 if (pgdat->node_spanned_pages)
222 node_pages = free_all_bootmem_node(pgdat);
224 totalram_pages += node_pages;
226 node_high_memory = (void *)__va((pgdat->node_start_pfn +
227 pgdat->node_spanned_pages) <<
229 if (node_high_memory > high_memory)
230 high_memory = node_high_memory;
233 /* Set this up early, so we can take care of the zero page */
236 /* clear the zero-page */
237 memset(empty_zero_page, 0, PAGE_SIZE);
238 __flush_wback_region(empty_zero_page, PAGE_SIZE);
240 codesize = (unsigned long) &_etext - (unsigned long) &_text;
241 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
242 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
244 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
245 "%dk data, %dk init)\n",
246 nr_free_pages() << (PAGE_SHIFT-10),
247 num_physpages << (PAGE_SHIFT-10),
252 /* Initialize the vDSO */
256 void free_initmem(void)
260 addr = (unsigned long)(&__init_begin);
261 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
262 ClearPageReserved(virt_to_page(addr));
263 init_page_count(virt_to_page(addr));
267 printk("Freeing unused kernel memory: %ldk freed\n",
268 ((unsigned long)&__init_end -
269 (unsigned long)&__init_begin) >> 10);
272 #ifdef CONFIG_BLK_DEV_INITRD
273 void free_initrd_mem(unsigned long start, unsigned long end)
276 for (p = start; p < end; p += PAGE_SIZE) {
277 ClearPageReserved(virt_to_page(p));
278 init_page_count(virt_to_page(p));
282 printk("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
286 #ifdef CONFIG_MEMORY_HOTPLUG
287 int arch_add_memory(int nid, u64 start, u64 size)
290 unsigned long start_pfn = start >> PAGE_SHIFT;
291 unsigned long nr_pages = size >> PAGE_SHIFT;
294 pgdat = NODE_DATA(nid);
296 /* We only have ZONE_NORMAL, so this is easy.. */
297 ret = __add_pages(nid, pgdat->node_zones + ZONE_NORMAL,
298 start_pfn, nr_pages);
300 printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
304 EXPORT_SYMBOL_GPL(arch_add_memory);
307 int memory_add_physaddr_to_nid(u64 addr)
309 /* Node 0 for now.. */
312 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
315 #endif /* CONFIG_MEMORY_HOTPLUG */
318 int __in_29bit_mode(void)
320 return !(ctrl_inl(PMB_PASCR) & PASCR_SE);
322 #endif /* CONFIG_PMB */