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/module.h>
26 #include <linux/types.h>
28 #include <linux/vmalloc.h>
29 #include <linux/init.h>
30 #include <linux/highmem.h>
32 #include <asm/pgtable.h>
33 #include <asm/pgalloc.h>
38 unsigned long ioremap_base;
39 unsigned long ioremap_bot;
42 #if defined(CONFIG_6xx) || defined(CONFIG_POWER3)
46 #if defined(CONFIG_FSL_BOOKE)
50 extern char etext[], _stext[];
53 extern void hash_page_sync(void);
57 extern unsigned long v_mapped_by_bats(unsigned long va);
58 extern unsigned long p_mapped_by_bats(unsigned long pa);
59 void setbat(int index, unsigned long virt, unsigned long phys,
60 unsigned int size, int flags);
62 #else /* !HAVE_BATS */
63 #define v_mapped_by_bats(x) (0UL)
64 #define p_mapped_by_bats(x) (0UL)
65 #endif /* HAVE_BATS */
68 extern unsigned int tlbcam_index;
69 extern unsigned int num_tlbcam_entries;
70 extern unsigned long v_mapped_by_tlbcam(unsigned long va);
71 extern unsigned long p_mapped_by_tlbcam(unsigned long pa);
72 #else /* !HAVE_TLBCAM */
73 #define v_mapped_by_tlbcam(x) (0UL)
74 #define p_mapped_by_tlbcam(x) (0UL)
75 #endif /* HAVE_TLBCAM */
77 #ifdef CONFIG_PTE_64BIT
78 /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
84 pgd_t *pgd_alloc(struct mm_struct *mm)
88 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 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|__GFP_ZERO);
106 pte = (pte_t *)early_get_page();
113 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
115 struct page *ptepage;
117 #ifdef CONFIG_HIGHPTE
118 int flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
120 int flags = GFP_KERNEL | __GFP_REPEAT;
123 ptepage = alloc_pages(flags, 0);
125 clear_highpage(ptepage);
129 void pte_free_kernel(pte_t *pte)
134 free_page((unsigned long)pte);
137 void pte_free(struct page *ptepage)
142 __free_page(ptepage);
145 #ifndef CONFIG_PHYS_64BIT
147 ioremap(phys_addr_t addr, unsigned long size)
149 return __ioremap(addr, size, _PAGE_NO_CACHE);
151 #else /* CONFIG_PHYS_64BIT */
153 ioremap64(unsigned long long addr, unsigned long size)
155 return __ioremap(addr, size, _PAGE_NO_CACHE);
159 ioremap(phys_addr_t addr, unsigned long size)
161 phys_addr_t addr64 = fixup_bigphys_addr(addr, size);
163 return ioremap64(addr64, size);
165 #endif /* CONFIG_PHYS_64BIT */
168 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
175 * Choose an address to map it to.
176 * Once the vmalloc system is running, we use it.
177 * Before then, we use space going down from ioremap_base
178 * (ioremap_bot records where we're up to).
180 p = addr & PAGE_MASK;
181 size = PAGE_ALIGN(addr + size) - p;
184 * If the address lies within the first 16 MB, assume it's in ISA
187 if (p < 16*1024*1024)
191 * Don't allow anybody to remap normal RAM that we're using.
192 * mem_init() sets high_memory so only do the check after that.
194 if ( mem_init_done && (p < virt_to_phys(high_memory)) )
196 printk("__ioremap(): phys addr "PHYS_FMT" is RAM lr %p\n", p,
197 __builtin_return_address(0));
205 * Is it already mapped? Perhaps overlapped by a previous
206 * BAT mapping. If the whole area is mapped then we're done,
207 * otherwise remap it since we want to keep the virt addrs for
208 * each request contiguous.
210 * We make the assumption here that if the bottom and top
211 * of the range we want are mapped then it's mapped to the
212 * same virt address (and this is contiguous).
215 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
218 if ((v = p_mapped_by_tlbcam(p)))
222 struct vm_struct *area;
223 area = get_vm_area(size, VM_IOREMAP);
226 v = (unsigned long) area->addr;
228 v = (ioremap_bot -= size);
231 if ((flags & _PAGE_PRESENT) == 0)
232 flags |= _PAGE_KERNEL;
233 if (flags & _PAGE_NO_CACHE)
234 flags |= _PAGE_GUARDED;
237 * Should check if it is a candidate for a BAT mapping
241 for (i = 0; i < size && err == 0; i += PAGE_SIZE)
242 err = map_page(v+i, p+i, flags);
250 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
253 void iounmap(volatile void __iomem *addr)
256 * If mapped by BATs then there is nothing to do.
257 * Calling vfree() generates a benign warning.
259 if (v_mapped_by_bats((unsigned long)addr)) return;
261 if (addr > high_memory && (unsigned long) addr < ioremap_bot)
262 vunmap((void *) (PAGE_MASK & (unsigned long)addr));
265 void __iomem *ioport_map(unsigned long port, unsigned int len)
267 return (void __iomem *) (port + _IO_BASE);
270 void ioport_unmap(void __iomem *addr)
274 EXPORT_SYMBOL(ioport_map);
275 EXPORT_SYMBOL(ioport_unmap);
278 map_page(unsigned long va, phys_addr_t pa, int flags)
284 spin_lock(&init_mm.page_table_lock);
285 /* Use upper 10 bits of VA to index the first level map */
286 pd = pmd_offset(pgd_offset_k(va), va);
287 /* Use middle 10 bits of VA to index the second-level map */
288 pg = pte_alloc_kernel(&init_mm, pd, va);
291 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags)));
293 flush_HPTE(0, va, pmd_val(*pd));
295 spin_unlock(&init_mm.page_table_lock);
300 * Map in all of physical memory starting at KERNELBASE.
302 void __init mapin_ram(void)
304 unsigned long v, p, s, f;
308 p = PPC_MEMSTART + s;
309 for (; s < total_lowmem; s += PAGE_SIZE) {
310 if ((char *) v >= _stext && (char *) v < etext)
320 /* is x a power of 2? */
321 #define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0))
323 /* is x a power of 4? */
324 #define is_power_of_4(x) ((x) != 0 && (((x) & (x-1)) == 0) && (ffs(x) & 1))
327 * Set up a mapping for a block of I/O.
328 * virt, phys, size must all be page-aligned.
329 * This should only be called before ioremap is called.
331 void __init io_block_mapping(unsigned long virt, phys_addr_t phys,
332 unsigned int size, int flags)
336 if (virt > KERNELBASE && virt < ioremap_bot)
337 ioremap_bot = ioremap_base = virt;
341 * Use a BAT for this if possible...
343 if (io_bat_index < 2 && is_power_of_2(size)
344 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) {
345 setbat(io_bat_index, virt, phys, size, flags);
349 #endif /* HAVE_BATS */
353 * Use a CAM for this if possible...
355 if (tlbcam_index < num_tlbcam_entries && is_power_of_4(size)
356 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) {
357 settlbcam(tlbcam_index, virt, phys, size, flags, 0);
361 #endif /* HAVE_TLBCAM */
363 /* No BATs available, put it in the page tables. */
364 for (i = 0; i < size; i += PAGE_SIZE)
365 map_page(virt + i, phys + i, flags);
368 /* Scan the real Linux page tables and return a PTE pointer for
369 * a virtual address in a context.
370 * Returns true (1) if PTE was found, zero otherwise. The pointer to
371 * the PTE pointer is unmodified if PTE is not found.
374 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep)
381 pgd = pgd_offset(mm, addr & PAGE_MASK);
383 pmd = pmd_offset(pgd, addr & PAGE_MASK);
384 if (pmd_present(*pmd)) {
385 pte = pte_offset_map(pmd, addr & PAGE_MASK);
389 /* XXX caller needs to do pte_unmap, yuck */
396 /* Find physical address for this virtual address. Normally used by
397 * I/O functions, but anyone can call it.
399 unsigned long iopa(unsigned long addr)
403 /* I don't know why this won't work on PMacs or CHRP. It
404 * appears there is some bug, or there is some implicit
405 * mapping done not properly represented by BATs or in page
406 * tables.......I am actively working on resolving this, but
407 * can't hold up other stuff. -- Dan
410 struct mm_struct *mm;
413 pa = v_mapped_by_bats(addr);
417 /* Allow mapping of user addresses (within the thread)
418 * for DMA if necessary.
420 if (addr < TASK_SIZE)
426 if (get_pteptr(mm, addr, &pte)) {
427 pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
434 /* This is will find the virtual address for a physical one....
435 * Swiped from APUS, could be dangerous :-).
436 * This is only a placeholder until I really find a way to make this
440 mm_ptov (unsigned long paddr)
444 if (paddr < 16*1024*1024)
445 ret = ZTWO_VADDR(paddr);
449 for (i = 0; i < kmap_chunk_count;){
450 unsigned long phys = kmap_chunks[i++];
451 unsigned long size = kmap_chunks[i++];
452 unsigned long virt = kmap_chunks[i++];
454 && paddr < (phys + size)){
455 ret = virt + paddr - phys;
460 ret = (unsigned long) __va(paddr);
464 printk ("PTOV(%lx)=%lx\n", paddr, ret);
467 ret = (unsigned long)paddr + KERNELBASE;