2 * This file contains the routines setting up the linux page tables.
5 * Derived from arch/ppc/mm/init.c:
6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
8 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
9 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
10 * Copyright (C) 1996 Paul Mackerras
12 * Derived from "arch/i386/mm/init.c"
13 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/types.h>
26 #include <linux/vmalloc.h>
27 #include <linux/init.h>
28 #include <linux/highmem.h>
29 #include <linux/memblock.h>
30 #include <linux/slab.h>
32 #include <asm/pgtable.h>
33 #include <asm/pgalloc.h>
34 #include <asm/fixmap.h>
36 #include <asm/setup.h>
37 #include <asm/sections.h>
41 unsigned long ioremap_bot;
42 EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
44 extern char etext[], _stext[], _sinittext[], _einittext[];
46 __ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
50 if (slab_is_available()) {
51 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
53 pte = __va(memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE));
60 pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
64 gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT;
66 ptepage = alloc_pages(flags, 0);
69 if (!pgtable_page_ctor(ptepage)) {
77 ioremap(phys_addr_t addr, unsigned long size)
79 pgprot_t prot = pgprot_noncached(PAGE_KERNEL);
81 return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
83 EXPORT_SYMBOL(ioremap);
86 ioremap_wc(phys_addr_t addr, unsigned long size)
88 pgprot_t prot = pgprot_noncached_wc(PAGE_KERNEL);
90 return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
92 EXPORT_SYMBOL(ioremap_wc);
95 ioremap_wt(phys_addr_t addr, unsigned long size)
97 pgprot_t prot = pgprot_cached_wthru(PAGE_KERNEL);
99 return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
101 EXPORT_SYMBOL(ioremap_wt);
104 ioremap_coherent(phys_addr_t addr, unsigned long size)
106 pgprot_t prot = pgprot_cached(PAGE_KERNEL);
108 return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
110 EXPORT_SYMBOL(ioremap_coherent);
113 ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
115 pte_t pte = __pte(flags);
117 /* writeable implies dirty for kernel addresses */
119 pte = pte_mkdirty(pte);
121 /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
122 pte = pte_exprotect(pte);
123 pte = pte_mkprivileged(pte);
125 return __ioremap_caller(addr, size, pte_pgprot(pte), __builtin_return_address(0));
127 EXPORT_SYMBOL(ioremap_prot);
130 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
132 return __ioremap_caller(addr, size, __pgprot(flags), __builtin_return_address(0));
136 __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller)
143 * Choose an address to map it to.
144 * Once the vmalloc system is running, we use it.
145 * Before then, we use space going down from IOREMAP_TOP
146 * (ioremap_bot records where we're up to).
148 p = addr & PAGE_MASK;
149 size = PAGE_ALIGN(addr + size) - p;
152 * If the address lies within the first 16 MB, assume it's in ISA
155 if (p < 16*1024*1024)
158 #ifndef CONFIG_CRASH_DUMP
160 * Don't allow anybody to remap normal RAM that we're using.
161 * mem_init() sets high_memory so only do the check after that.
163 if (slab_is_available() && (p < virt_to_phys(high_memory)) &&
164 page_is_ram(__phys_to_pfn(p))) {
165 printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
166 (unsigned long long)p, __builtin_return_address(0));
175 * Is it already mapped? Perhaps overlapped by a previous
178 v = p_block_mapped(p);
182 if (slab_is_available()) {
183 struct vm_struct *area;
184 area = get_vm_area_caller(size, VM_IOREMAP, caller);
188 v = (unsigned long) area->addr;
190 v = (ioremap_bot -= size);
194 * Should check if it is a candidate for a BAT mapping
198 for (i = 0; i < size && err == 0; i += PAGE_SIZE)
199 err = map_kernel_page(v + i, p + i, prot);
201 if (slab_is_available())
207 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
209 EXPORT_SYMBOL(__ioremap);
211 void iounmap(volatile void __iomem *addr)
214 * If mapped by BATs then there is nothing to do.
215 * Calling vfree() generates a benign warning.
217 if (v_block_mapped((unsigned long)addr))
220 if (addr > high_memory && (unsigned long) addr < ioremap_bot)
221 vunmap((void *) (PAGE_MASK & (unsigned long)addr));
223 EXPORT_SYMBOL(iounmap);
225 int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
231 /* Use upper 10 bits of VA to index the first level map */
232 pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
233 /* Use middle 10 bits of VA to index the second-level map */
234 pg = pte_alloc_kernel(pd, va);
237 /* The PTE should never be already set nor present in the
240 BUG_ON((pte_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot));
241 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
248 * Map in a chunk of physical memory starting at start.
250 static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
258 p = memstart_addr + s;
259 for (; s < top; s += PAGE_SIZE) {
260 ktext = ((char *)v >= _stext && (char *)v < etext) ||
261 ((char *)v >= _sinittext && (char *)v < _einittext);
262 map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
263 #ifdef CONFIG_PPC_STD_MMU_32
265 hash_preload(&init_mm, v, false, 0x300);
272 void __init mapin_ram(void)
274 unsigned long s, top;
278 s = mmu_mapin_ram(top);
279 __mapin_ram_chunk(s, top);
281 if (!wii_hole_size) {
282 s = mmu_mapin_ram(total_lowmem);
283 __mapin_ram_chunk(s, total_lowmem);
285 top = wii_hole_start;
286 s = mmu_mapin_ram(top);
287 __mapin_ram_chunk(s, top);
289 top = memblock_end_of_DRAM();
290 s = wii_mmu_mapin_mem2(top);
291 __mapin_ram_chunk(s, top);
296 /* Scan the real Linux page tables and return a PTE pointer for
297 * a virtual address in a context.
298 * Returns true (1) if PTE was found, zero otherwise. The pointer to
299 * the PTE pointer is unmodified if PTE is not found.
302 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
310 pgd = pgd_offset(mm, addr & PAGE_MASK);
312 pud = pud_offset(pgd, addr & PAGE_MASK);
313 if (pud && pud_present(*pud)) {
314 pmd = pmd_offset(pud, addr & PAGE_MASK);
315 if (pmd_present(*pmd)) {
316 pte = pte_offset_map(pmd, addr & PAGE_MASK);
322 /* XXX caller needs to do pte_unmap, yuck */
330 static int __change_page_attr_noflush(struct page *page, pgprot_t prot)
334 unsigned long address;
336 BUG_ON(PageHighMem(page));
337 address = (unsigned long)page_address(page);
339 if (v_block_mapped(address))
341 if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
343 __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
350 * Change the page attributes of an page in the linear mapping.
352 * THIS DOES NOTHING WITH BAT MAPPINGS, DEBUG USE ONLY
354 static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
358 struct page *start = page;
360 local_irq_save(flags);
361 for (i = 0; i < numpages; i++, page++) {
362 err = __change_page_attr_noflush(page, prot);
367 local_irq_restore(flags);
368 flush_tlb_kernel_range((unsigned long)page_address(start),
369 (unsigned long)page_address(page));
373 void mark_initmem_nx(void)
375 struct page *page = virt_to_page(_sinittext);
376 unsigned long numpages = PFN_UP((unsigned long)_einittext) -
377 PFN_DOWN((unsigned long)_sinittext);
379 change_page_attr(page, numpages, PAGE_KERNEL);
382 #ifdef CONFIG_STRICT_KERNEL_RWX
383 void mark_rodata_ro(void)
386 unsigned long numpages;
388 page = virt_to_page(_stext);
389 numpages = PFN_UP((unsigned long)_etext) -
390 PFN_DOWN((unsigned long)_stext);
392 change_page_attr(page, numpages, PAGE_KERNEL_ROX);
394 * mark .rodata as read only. Use __init_begin rather than __end_rodata
395 * to cover NOTES and EXCEPTION_TABLE.
397 page = virt_to_page(__start_rodata);
398 numpages = PFN_UP((unsigned long)__init_begin) -
399 PFN_DOWN((unsigned long)__start_rodata);
401 change_page_attr(page, numpages, PAGE_KERNEL_RO);
405 #ifdef CONFIG_DEBUG_PAGEALLOC
406 void __kernel_map_pages(struct page *page, int numpages, int enable)
408 if (PageHighMem(page))
411 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
413 #endif /* CONFIG_DEBUG_PAGEALLOC */