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
11 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
13 * Derived from "arch/i386/mm/init.c"
14 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation; either version
19 * 2 of the License, or (at your option) any later version.
23 #include <linux/config.h>
24 #include <linux/kernel.h>
25 #include <linux/types.h>
27 #include <linux/vmalloc.h>
28 #include <linux/init.h>
29 #include <linux/highmem.h>
31 #include <asm/pgtable.h>
32 #include <asm/pgalloc.h>
37 unsigned long ioremap_base;
38 unsigned long ioremap_bot;
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 int num_tlbcam_entries;
69 extern unsigned long v_mapped_by_tlbcam(unsigned long va);
70 extern unsigned long p_mapped_by_tlbcam(unsigned long pa);
71 #else /* !HAVE_TLBCAM */
72 #define v_mapped_by_tlbcam(x) (0UL)
73 #define p_mapped_by_tlbcam(x) (0UL)
74 #endif /* HAVE_TLBCAM */
77 /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
83 pgd_t *pgd_alloc(struct mm_struct *mm)
87 if ((ret = (pgd_t *)__get_free_pages(GFP_KERNEL, PGDIR_ORDER)) != NULL)
88 clear_pages(ret, PGDIR_ORDER);
92 void pgd_free(pgd_t *pgd)
94 free_pages((unsigned long)pgd, PGDIR_ORDER);
97 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
100 extern int mem_init_done;
101 extern void *early_get_page(void);
104 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
106 struct page *ptepage = virt_to_page(pte);
107 ptepage->mapping = (void *) mm;
108 ptepage->index = address & PMD_MASK;
111 pte = (pte_t *)early_get_page();
117 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
119 struct page *ptepage;
121 #ifdef CONFIG_HIGHPTE
122 int flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
124 int flags = GFP_KERNEL | __GFP_REPEAT;
127 ptepage = alloc_pages(flags, 0);
129 ptepage->mapping = (void *) mm;
130 ptepage->index = address & PMD_MASK;
131 clear_highpage(ptepage);
136 void pte_free_kernel(pte_t *pte)
141 virt_to_page(pte)->mapping = NULL;
142 free_page((unsigned long)pte);
145 void pte_free(struct page *ptepage)
150 ptepage->mapping = NULL;
151 __free_page(ptepage);
156 ioremap(phys_addr_t addr, unsigned long size)
158 return __ioremap(addr, size, _PAGE_NO_CACHE);
160 #else /* CONFIG_44x */
162 ioremap64(unsigned long long addr, unsigned long size)
164 return __ioremap(addr, size, _PAGE_NO_CACHE);
168 ioremap(phys_addr_t addr, unsigned long size)
170 phys_addr_t addr64 = fixup_bigphys_addr(addr, size);
172 return ioremap64(addr64, size);
174 #endif /* CONFIG_44x */
177 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
184 * Choose an address to map it to.
185 * Once the vmalloc system is running, we use it.
186 * Before then, we use space going down from ioremap_base
187 * (ioremap_bot records where we're up to).
189 p = addr & PAGE_MASK;
190 size = PAGE_ALIGN(addr + size) - p;
193 * If the address lies within the first 16 MB, assume it's in ISA
196 if (p < 16*1024*1024)
200 * Don't allow anybody to remap normal RAM that we're using.
201 * mem_init() sets high_memory so only do the check after that.
203 if ( mem_init_done && (p < virt_to_phys(high_memory)) )
205 printk("__ioremap(): phys addr "PTE_FMT" is RAM lr %p\n", p,
206 __builtin_return_address(0));
214 * Is it already mapped? Perhaps overlapped by a previous
215 * BAT mapping. If the whole area is mapped then we're done,
216 * otherwise remap it since we want to keep the virt addrs for
217 * each request contiguous.
219 * We make the assumption here that if the bottom and top
220 * of the range we want are mapped then it's mapped to the
221 * same virt address (and this is contiguous).
224 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
227 if ((v = p_mapped_by_tlbcam(p)))
231 struct vm_struct *area;
232 area = get_vm_area(size, VM_IOREMAP);
235 v = (unsigned long) area->addr;
237 v = (ioremap_bot -= size);
240 if ((flags & _PAGE_PRESENT) == 0)
241 flags |= _PAGE_KERNEL;
242 if (flags & _PAGE_NO_CACHE)
243 flags |= _PAGE_GUARDED;
246 * Should check if it is a candidate for a BAT mapping
250 for (i = 0; i < size && err == 0; i += PAGE_SIZE)
251 err = map_page(v+i, p+i, flags);
259 return (void *) (v + ((unsigned long)addr & ~PAGE_MASK));
262 void iounmap(void *addr)
265 * If mapped by BATs then there is nothing to do.
266 * Calling vfree() generates a benign warning.
268 if (v_mapped_by_bats((unsigned long)addr)) return;
270 if (addr > high_memory && (unsigned long) addr < ioremap_bot)
271 vunmap((void *) (PAGE_MASK & (unsigned long)addr));
275 map_page(unsigned long va, phys_addr_t pa, int flags)
281 spin_lock(&init_mm.page_table_lock);
282 /* Use upper 10 bits of VA to index the first level map */
283 pd = pmd_offset(pgd_offset_k(va), va);
284 /* Use middle 10 bits of VA to index the second-level map */
285 pg = pte_alloc_kernel(&init_mm, pd, va);
288 set_pte(pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags)));
290 flush_HPTE(0, va, pmd_val(*pd));
292 spin_unlock(&init_mm.page_table_lock);
297 * Map in all of physical memory starting at KERNELBASE.
299 void __init mapin_ram(void)
301 unsigned long v, p, s, f;
305 p = PPC_MEMSTART + s;
306 for (; s < total_lowmem; s += PAGE_SIZE) {
307 if ((char *) v >= _stext && (char *) v < etext)
317 /* is x a power of 2? */
318 #define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0))
320 /* is x a power of 4? */
321 #define is_power_of_4(x) ((x) != 0 && (((x) & (x-1)) == 0) && (ffs(x) & 1))
324 * Set up a mapping for a block of I/O.
325 * virt, phys, size must all be page-aligned.
326 * This should only be called before ioremap is called.
328 void __init io_block_mapping(unsigned long virt, phys_addr_t phys,
329 unsigned int size, int flags)
333 if (virt > KERNELBASE && virt < ioremap_bot)
334 ioremap_bot = ioremap_base = virt;
338 * Use a BAT for this if possible...
340 if (io_bat_index < 2 && is_power_of_2(size)
341 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) {
342 setbat(io_bat_index, virt, phys, size, flags);
346 #endif /* HAVE_BATS */
350 * Use a CAM for this if possible...
352 if (tlbcam_index < num_tlbcam_entries && is_power_of_4(size)
353 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) {
354 settlbcam(tlbcam_index, virt, phys, size, flags, 0);
358 #endif /* HAVE_TLBCAM */
360 /* No BATs available, put it in the page tables. */
361 for (i = 0; i < size; i += PAGE_SIZE)
362 map_page(virt + i, phys + i, flags);
365 /* Scan the real Linux page tables and return a PTE pointer for
366 * a virtual address in a context.
367 * Returns true (1) if PTE was found, zero otherwise. The pointer to
368 * the PTE pointer is unmodified if PTE is not found.
371 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep)
378 pgd = pgd_offset(mm, addr & PAGE_MASK);
380 pmd = pmd_offset(pgd, addr & PAGE_MASK);
381 if (pmd_present(*pmd)) {
382 pte = pte_offset_map(pmd, addr & PAGE_MASK);
386 /* XXX caller needs to do pte_unmap, yuck */
393 /* Find physical address for this virtual address. Normally used by
394 * I/O functions, but anyone can call it.
396 unsigned long iopa(unsigned long addr)
400 /* I don't know why this won't work on PMacs or CHRP. It
401 * appears there is some bug, or there is some implicit
402 * mapping done not properly represented by BATs or in page
403 * tables.......I am actively working on resolving this, but
404 * can't hold up other stuff. -- Dan
407 struct mm_struct *mm;
410 pa = v_mapped_by_bats(addr);
414 /* Allow mapping of user addresses (within the thread)
415 * for DMA if necessary.
417 if (addr < TASK_SIZE)
423 if (get_pteptr(mm, addr, &pte)) {
424 pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
431 /* This is will find the virtual address for a physical one....
432 * Swiped from APUS, could be dangerous :-).
433 * This is only a placeholder until I really find a way to make this
437 mm_ptov (unsigned long paddr)
441 if (paddr < 16*1024*1024)
442 ret = ZTWO_VADDR(paddr);
446 for (i = 0; i < kmap_chunk_count;){
447 unsigned long phys = kmap_chunks[i++];
448 unsigned long size = kmap_chunks[i++];
449 unsigned long virt = kmap_chunks[i++];
451 && paddr < (phys + size)){
452 ret = virt + paddr - phys;
457 ret = (unsigned long) __va(paddr);
461 printk ("PTOV(%lx)=%lx\n", paddr, ret);
464 ret = (unsigned long)paddr + KERNELBASE;