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>
30 #include <asm/pgtable.h>
31 #include <asm/pgalloc.h>
36 unsigned long ioremap_base;
37 unsigned long ioremap_bot;
38 EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
41 #if defined(CONFIG_6xx) || defined(CONFIG_POWER3)
45 #if defined(CONFIG_FSL_BOOKE)
49 extern char etext[], _stext[];
52 extern void hash_page_sync(void);
56 extern unsigned long v_mapped_by_bats(unsigned long va);
57 extern unsigned long p_mapped_by_bats(unsigned long pa);
58 void setbat(int index, unsigned long virt, unsigned long phys,
59 unsigned int size, int flags);
61 #else /* !HAVE_BATS */
62 #define v_mapped_by_bats(x) (0UL)
63 #define p_mapped_by_bats(x) (0UL)
64 #endif /* HAVE_BATS */
67 extern unsigned int tlbcam_index;
68 extern unsigned long v_mapped_by_tlbcam(unsigned long va);
69 extern unsigned long p_mapped_by_tlbcam(unsigned long pa);
70 #else /* !HAVE_TLBCAM */
71 #define v_mapped_by_tlbcam(x) (0UL)
72 #define p_mapped_by_tlbcam(x) (0UL)
73 #endif /* HAVE_TLBCAM */
75 #ifdef CONFIG_PTE_64BIT
76 /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
82 pgd_t *pgd_alloc(struct mm_struct *mm)
86 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER);
90 void pgd_free(pgd_t *pgd)
92 free_pages((unsigned long)pgd, PGDIR_ORDER);
95 __init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
98 extern int mem_init_done;
99 extern void *early_get_page(void);
102 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
104 pte = (pte_t *)early_get_page();
111 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
113 struct page *ptepage;
115 #ifdef CONFIG_HIGHPTE
116 gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
118 gfp_t flags = GFP_KERNEL | __GFP_REPEAT;
121 ptepage = alloc_pages(flags, 0);
123 clear_highpage(ptepage);
127 void pte_free_kernel(pte_t *pte)
132 free_page((unsigned long)pte);
135 void pte_free(struct page *ptepage)
140 __free_page(ptepage);
144 ioremap(phys_addr_t addr, unsigned long size)
146 return __ioremap(addr, size, _PAGE_NO_CACHE);
148 EXPORT_SYMBOL(ioremap);
151 ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags)
153 return __ioremap(addr, size, flags);
155 EXPORT_SYMBOL(ioremap_flags);
158 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
165 * Choose an address to map it to.
166 * Once the vmalloc system is running, we use it.
167 * Before then, we use space going down from ioremap_base
168 * (ioremap_bot records where we're up to).
170 p = addr & PAGE_MASK;
171 size = PAGE_ALIGN(addr + size) - p;
174 * If the address lies within the first 16 MB, assume it's in ISA
177 if (p < 16*1024*1024)
181 * Don't allow anybody to remap normal RAM that we're using.
182 * mem_init() sets high_memory so only do the check after that.
184 if (mem_init_done && (p < virt_to_phys(high_memory))) {
185 printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n",
186 (unsigned long long)p, __builtin_return_address(0));
194 * Is it already mapped? Perhaps overlapped by a previous
195 * BAT mapping. If the whole area is mapped then we're done,
196 * otherwise remap it since we want to keep the virt addrs for
197 * each request contiguous.
199 * We make the assumption here that if the bottom and top
200 * of the range we want are mapped then it's mapped to the
201 * same virt address (and this is contiguous).
204 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
207 if ((v = p_mapped_by_tlbcam(p)))
211 struct vm_struct *area;
212 area = get_vm_area(size, VM_IOREMAP);
215 v = (unsigned long) area->addr;
217 v = (ioremap_bot -= size);
220 if ((flags & _PAGE_PRESENT) == 0)
221 flags |= _PAGE_KERNEL;
222 if (flags & _PAGE_NO_CACHE)
223 flags |= _PAGE_GUARDED;
226 * Should check if it is a candidate for a BAT mapping
230 for (i = 0; i < size && err == 0; i += PAGE_SIZE)
231 err = map_page(v+i, p+i, flags);
239 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
241 EXPORT_SYMBOL(__ioremap);
243 void iounmap(volatile void __iomem *addr)
246 * If mapped by BATs then there is nothing to do.
247 * Calling vfree() generates a benign warning.
249 if (v_mapped_by_bats((unsigned long)addr)) return;
251 if (addr > high_memory && (unsigned long) addr < ioremap_bot)
252 vunmap((void *) (PAGE_MASK & (unsigned long)addr));
254 EXPORT_SYMBOL(iounmap);
256 int map_page(unsigned long va, phys_addr_t pa, int flags)
262 /* Use upper 10 bits of VA to index the first level map */
263 pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
264 /* Use middle 10 bits of VA to index the second-level map */
265 pg = pte_alloc_kernel(pd, va);
268 /* The PTE should never be already set nor present in the
271 BUG_ON(pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE));
272 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
279 * Map in all of physical memory starting at KERNELBASE.
281 void __init mapin_ram(void)
283 unsigned long v, p, s, f;
288 p = PPC_MEMSTART + s;
289 for (; s < total_lowmem; s += PAGE_SIZE) {
290 ktext = ((char *) v >= _stext && (char *) v < etext);
291 f = ktext ?_PAGE_RAM_TEXT : _PAGE_RAM;
293 #ifdef CONFIG_PPC_STD_MMU_32
295 hash_preload(&init_mm, v, 0, 0x300);
302 /* is x a power of 4? */
303 #define is_power_of_4(x) is_power_of_2(x) && (ffs(x) & 1)
305 /* Scan the real Linux page tables and return a PTE pointer for
306 * a virtual address in a context.
307 * Returns true (1) if PTE was found, zero otherwise. The pointer to
308 * the PTE pointer is unmodified if PTE is not found.
311 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
319 pgd = pgd_offset(mm, addr & PAGE_MASK);
321 pud = pud_offset(pgd, addr & PAGE_MASK);
322 if (pud && pud_present(*pud)) {
323 pmd = pmd_offset(pud, addr & PAGE_MASK);
324 if (pmd_present(*pmd)) {
325 pte = pte_offset_map(pmd, addr & PAGE_MASK);
331 /* XXX caller needs to do pte_unmap, yuck */
339 #ifdef CONFIG_DEBUG_PAGEALLOC
341 static int __change_page_attr(struct page *page, pgprot_t prot)
345 unsigned long address;
347 BUG_ON(PageHighMem(page));
348 address = (unsigned long)page_address(page);
350 if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address))
352 if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
354 set_pte_at(&init_mm, address, kpte, mk_pte(page, prot));
356 flush_HPTE(0, address, pmd_val(*kpmd));
363 * Change the page attributes of an page in the linear mapping.
365 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY
367 static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
372 local_irq_save(flags);
373 for (i = 0; i < numpages; i++, page++) {
374 err = __change_page_attr(page, prot);
378 local_irq_restore(flags);
383 void kernel_map_pages(struct page *page, int numpages, int enable)
385 if (PageHighMem(page))
388 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
390 #endif /* CONFIG_DEBUG_PAGEALLOC */