[MIPS] Use common definitions from asm-generic/signal.h
[linux-2.6/linux-mips/linux-dm7025.git] / arch / powerpc / mm / pgtable_32.c
blob8fcacb0239da8a9caedd78196159cc88307628b2
1 /*
2 * This file contains the routines setting up the linux page tables.
3 * -- paulus
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/kernel.h>
24 #include <linux/module.h>
25 #include <linux/types.h>
26 #include <linux/mm.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>
33 #include <asm/io.h>
35 #include "mmu_decl.h"
37 unsigned long ioremap_base;
38 unsigned long ioremap_bot;
39 EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
40 int io_bat_index;
42 #if defined(CONFIG_6xx) || defined(CONFIG_POWER3)
43 #define HAVE_BATS 1
44 #endif
46 #if defined(CONFIG_FSL_BOOKE)
47 #define HAVE_TLBCAM 1
48 #endif
50 extern char etext[], _stext[];
52 #ifdef CONFIG_SMP
53 extern void hash_page_sync(void);
54 #endif
56 #ifdef HAVE_BATS
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 */
67 #ifdef HAVE_TLBCAM
68 extern unsigned int tlbcam_index;
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 */
76 #ifdef CONFIG_PTE_64BIT
77 /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
78 #define PGDIR_ORDER 1
79 #else
80 #define PGDIR_ORDER 0
81 #endif
83 pgd_t *pgd_alloc(struct mm_struct *mm)
85 pgd_t *ret;
87 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER);
88 return ret;
91 void pgd_free(pgd_t *pgd)
93 free_pages((unsigned long)pgd, PGDIR_ORDER);
96 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
98 pte_t *pte;
99 extern int mem_init_done;
100 extern void *early_get_page(void);
102 if (mem_init_done) {
103 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
104 } else {
105 pte = (pte_t *)early_get_page();
106 if (pte)
107 clear_page(pte);
109 return pte;
112 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
114 struct page *ptepage;
116 #ifdef CONFIG_HIGHPTE
117 gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
118 #else
119 gfp_t flags = GFP_KERNEL | __GFP_REPEAT;
120 #endif
122 ptepage = alloc_pages(flags, 0);
123 if (ptepage)
124 clear_highpage(ptepage);
125 return ptepage;
128 void pte_free_kernel(pte_t *pte)
130 #ifdef CONFIG_SMP
131 hash_page_sync();
132 #endif
133 free_page((unsigned long)pte);
136 void pte_free(struct page *ptepage)
138 #ifdef CONFIG_SMP
139 hash_page_sync();
140 #endif
141 __free_page(ptepage);
144 #ifndef CONFIG_PHYS_64BIT
145 void __iomem *
146 ioremap(phys_addr_t addr, unsigned long size)
148 return __ioremap(addr, size, _PAGE_NO_CACHE);
150 #else /* CONFIG_PHYS_64BIT */
151 void __iomem *
152 ioremap64(unsigned long long addr, unsigned long size)
154 return __ioremap(addr, size, _PAGE_NO_CACHE);
156 EXPORT_SYMBOL(ioremap64);
158 void __iomem *
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 */
166 EXPORT_SYMBOL(ioremap);
168 void __iomem *
169 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
171 unsigned long v, i;
172 phys_addr_t p;
173 int err;
176 * Choose an address to map it to.
177 * Once the vmalloc system is running, we use it.
178 * Before then, we use space going down from ioremap_base
179 * (ioremap_bot records where we're up to).
181 p = addr & PAGE_MASK;
182 size = PAGE_ALIGN(addr + size) - p;
185 * If the address lies within the first 16 MB, assume it's in ISA
186 * memory space
188 if (p < 16*1024*1024)
189 p += _ISA_MEM_BASE;
192 * Don't allow anybody to remap normal RAM that we're using.
193 * mem_init() sets high_memory so only do the check after that.
195 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));
198 return NULL;
201 if (size == 0)
202 return NULL;
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).
213 * -- Cort
215 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
216 goto out;
218 if ((v = p_mapped_by_tlbcam(p)))
219 goto out;
221 if (mem_init_done) {
222 struct vm_struct *area;
223 area = get_vm_area(size, VM_IOREMAP);
224 if (area == 0)
225 return NULL;
226 v = (unsigned long) area->addr;
227 } else {
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
240 err = 0;
241 for (i = 0; i < size && err == 0; i += PAGE_SIZE)
242 err = map_page(v+i, p+i, flags);
243 if (err) {
244 if (mem_init_done)
245 vunmap((void *)v);
246 return NULL;
249 out:
250 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
252 EXPORT_SYMBOL(__ioremap);
254 void iounmap(volatile void __iomem *addr)
257 * If mapped by BATs then there is nothing to do.
258 * Calling vfree() generates a benign warning.
260 if (v_mapped_by_bats((unsigned long)addr)) return;
262 if (addr > high_memory && (unsigned long) addr < ioremap_bot)
263 vunmap((void *) (PAGE_MASK & (unsigned long)addr));
265 EXPORT_SYMBOL(iounmap);
267 void __iomem *ioport_map(unsigned long port, unsigned int len)
269 return (void __iomem *) (port + _IO_BASE);
272 void ioport_unmap(void __iomem *addr)
274 /* Nothing to do */
276 EXPORT_SYMBOL(ioport_map);
277 EXPORT_SYMBOL(ioport_unmap);
280 map_page(unsigned long va, phys_addr_t pa, int flags)
282 pmd_t *pd;
283 pte_t *pg;
284 int err = -ENOMEM;
286 /* Use upper 10 bits of VA to index the first level map */
287 pd = pmd_offset(pgd_offset_k(va), va);
288 /* Use middle 10 bits of VA to index the second-level map */
289 pg = pte_alloc_kernel(pd, va);
290 if (pg != 0) {
291 err = 0;
292 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags)));
293 if (mem_init_done)
294 flush_HPTE(0, va, pmd_val(*pd));
296 return err;
300 * Map in all of physical memory starting at KERNELBASE.
302 void __init mapin_ram(void)
304 unsigned long v, p, s, f;
306 s = mmu_mapin_ram();
307 v = KERNELBASE + s;
308 p = PPC_MEMSTART + s;
309 for (; s < total_lowmem; s += PAGE_SIZE) {
310 if ((char *) v >= _stext && (char *) v < etext)
311 f = _PAGE_RAM_TEXT;
312 else
313 f = _PAGE_RAM;
314 map_page(v, p, f);
315 v += PAGE_SIZE;
316 p += PAGE_SIZE;
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)
334 int i;
336 if (virt > KERNELBASE && virt < ioremap_bot)
337 ioremap_bot = ioremap_base = virt;
339 #ifdef HAVE_BATS
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);
346 ++io_bat_index;
347 return;
349 #endif /* HAVE_BATS */
351 #ifdef HAVE_TLBCAM
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);
358 ++tlbcam_index;
359 return;
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, pmd_t **pmdp)
376 pgd_t *pgd;
377 pmd_t *pmd;
378 pte_t *pte;
379 int retval = 0;
381 pgd = pgd_offset(mm, addr & PAGE_MASK);
382 if (pgd) {
383 pmd = pmd_offset(pgd, addr & PAGE_MASK);
384 if (pmd_present(*pmd)) {
385 pte = pte_offset_map(pmd, addr & PAGE_MASK);
386 if (pte) {
387 retval = 1;
388 *ptep = pte;
389 if (pmdp)
390 *pmdp = pmd;
391 /* XXX caller needs to do pte_unmap, yuck */
395 return(retval);
398 /* Find physical address for this virtual address. Normally used by
399 * I/O functions, but anyone can call it.
401 unsigned long iopa(unsigned long addr)
403 unsigned long pa;
405 /* I don't know why this won't work on PMacs or CHRP. It
406 * appears there is some bug, or there is some implicit
407 * mapping done not properly represented by BATs or in page
408 * tables.......I am actively working on resolving this, but
409 * can't hold up other stuff. -- Dan
411 pte_t *pte;
412 struct mm_struct *mm;
414 /* Check the BATs */
415 pa = v_mapped_by_bats(addr);
416 if (pa)
417 return pa;
419 /* Allow mapping of user addresses (within the thread)
420 * for DMA if necessary.
422 if (addr < TASK_SIZE)
423 mm = current->mm;
424 else
425 mm = &init_mm;
427 pa = 0;
428 if (get_pteptr(mm, addr, &pte, NULL)) {
429 pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
430 pte_unmap(pte);
433 return(pa);
436 /* This is will find the virtual address for a physical one....
437 * Swiped from APUS, could be dangerous :-).
438 * This is only a placeholder until I really find a way to make this
439 * work. -- Dan
441 unsigned long
442 mm_ptov (unsigned long paddr)
444 unsigned long ret;
445 #if 0
446 if (paddr < 16*1024*1024)
447 ret = ZTWO_VADDR(paddr);
448 else {
449 int i;
451 for (i = 0; i < kmap_chunk_count;){
452 unsigned long phys = kmap_chunks[i++];
453 unsigned long size = kmap_chunks[i++];
454 unsigned long virt = kmap_chunks[i++];
455 if (paddr >= phys
456 && paddr < (phys + size)){
457 ret = virt + paddr - phys;
458 goto exit;
462 ret = (unsigned long) __va(paddr);
464 exit:
465 #ifdef DEBUGPV
466 printk ("PTOV(%lx)=%lx\n", paddr, ret);
467 #endif
468 #else
469 ret = (unsigned long)paddr + KERNELBASE;
470 #endif
471 return ret;