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>
32 #include <asm/fixmap.h>
37 unsigned long ioremap_base
;
38 unsigned long ioremap_bot
;
39 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 phys_addr_t
v_mapped_by_bats(unsigned long va
);
53 extern unsigned long p_mapped_by_bats(phys_addr_t pa
);
54 void setbat(int index
, unsigned long virt
, phys_addr_t phys
,
55 unsigned int size
, int flags
);
57 #else /* !HAVE_BATS */
58 #define v_mapped_by_bats(x) (0UL)
59 #define p_mapped_by_bats(x) (0UL)
60 #endif /* HAVE_BATS */
63 extern unsigned int tlbcam_index
;
64 extern unsigned long v_mapped_by_tlbcam(unsigned long va
);
65 extern unsigned long p_mapped_by_tlbcam(unsigned long pa
);
66 #else /* !HAVE_TLBCAM */
67 #define v_mapped_by_tlbcam(x) (0UL)
68 #define p_mapped_by_tlbcam(x) (0UL)
69 #endif /* HAVE_TLBCAM */
71 #ifdef CONFIG_PTE_64BIT
72 /* Some processors use an 8kB pgdir because they have 8-byte Linux PTEs. */
78 pgd_t
*pgd_alloc(struct mm_struct
*mm
)
82 ret
= (pgd_t
*)__get_free_pages(GFP_KERNEL
|__GFP_ZERO
, PGDIR_ORDER
);
86 void pgd_free(struct mm_struct
*mm
, pgd_t
*pgd
)
88 free_pages((unsigned long)pgd
, PGDIR_ORDER
);
91 __init_refok pte_t
*pte_alloc_one_kernel(struct mm_struct
*mm
, unsigned long address
)
94 extern int mem_init_done
;
95 extern void *early_get_page(void);
98 pte
= (pte_t
*)__get_free_page(GFP_KERNEL
|__GFP_REPEAT
|__GFP_ZERO
);
100 pte
= (pte_t
*)early_get_page();
107 pgtable_t
pte_alloc_one(struct mm_struct
*mm
, unsigned long address
)
109 struct page
*ptepage
;
111 #ifdef CONFIG_HIGHPTE
112 gfp_t flags
= GFP_KERNEL
| __GFP_HIGHMEM
| __GFP_REPEAT
| __GFP_ZERO
;
114 gfp_t flags
= GFP_KERNEL
| __GFP_REPEAT
| __GFP_ZERO
;
117 ptepage
= alloc_pages(flags
, 0);
120 pgtable_page_ctor(ptepage
);
125 ioremap(phys_addr_t addr
, unsigned long size
)
127 return __ioremap(addr
, size
, _PAGE_NO_CACHE
| _PAGE_GUARDED
);
129 EXPORT_SYMBOL(ioremap
);
132 ioremap_flags(phys_addr_t addr
, unsigned long size
, unsigned long flags
)
134 /* writeable implies dirty for kernel addresses */
135 if (flags
& _PAGE_RW
)
136 flags
|= _PAGE_DIRTY
| _PAGE_HWWRITE
;
138 /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
139 flags
&= ~(_PAGE_USER
| _PAGE_EXEC
| _PAGE_HWEXEC
);
141 return __ioremap(addr
, size
, flags
);
143 EXPORT_SYMBOL(ioremap_flags
);
146 __ioremap(phys_addr_t addr
, unsigned long size
, unsigned long flags
)
152 /* Make sure we have the base flags */
153 if ((flags
& _PAGE_PRESENT
) == 0)
154 flags
|= _PAGE_KERNEL
;
156 /* Non-cacheable page cannot be coherent */
157 if (flags
& _PAGE_NO_CACHE
)
158 flags
&= ~_PAGE_COHERENT
;
161 * Choose an address to map it to.
162 * Once the vmalloc system is running, we use it.
163 * Before then, we use space going down from ioremap_base
164 * (ioremap_bot records where we're up to).
166 p
= addr
& PAGE_MASK
;
167 size
= PAGE_ALIGN(addr
+ size
) - p
;
170 * If the address lies within the first 16 MB, assume it's in ISA
173 if (p
< 16*1024*1024)
176 #ifndef CONFIG_CRASH_DUMP
178 * Don't allow anybody to remap normal RAM that we're using.
179 * mem_init() sets high_memory so only do the check after that.
181 if (mem_init_done
&& (p
< virt_to_phys(high_memory
))) {
182 printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n",
183 (unsigned long long)p
, __builtin_return_address(0));
192 * Is it already mapped? Perhaps overlapped by a previous
193 * BAT mapping. If the whole area is mapped then we're done,
194 * otherwise remap it since we want to keep the virt addrs for
195 * each request contiguous.
197 * We make the assumption here that if the bottom and top
198 * of the range we want are mapped then it's mapped to the
199 * same virt address (and this is contiguous).
202 if ((v
= p_mapped_by_bats(p
)) /*&& p_mapped_by_bats(p+size-1)*/ )
205 if ((v
= p_mapped_by_tlbcam(p
)))
209 struct vm_struct
*area
;
210 area
= get_vm_area(size
, VM_IOREMAP
);
213 v
= (unsigned long) area
->addr
;
215 v
= (ioremap_bot
-= size
);
219 * Should check if it is a candidate for a BAT mapping
223 for (i
= 0; i
< size
&& err
== 0; i
+= PAGE_SIZE
)
224 err
= map_page(v
+i
, p
+i
, flags
);
232 return (void __iomem
*) (v
+ ((unsigned long)addr
& ~PAGE_MASK
));
234 EXPORT_SYMBOL(__ioremap
);
236 void iounmap(volatile void __iomem
*addr
)
239 * If mapped by BATs then there is nothing to do.
240 * Calling vfree() generates a benign warning.
242 if (v_mapped_by_bats((unsigned long)addr
)) return;
244 if (addr
> high_memory
&& (unsigned long) addr
< ioremap_bot
)
245 vunmap((void *) (PAGE_MASK
& (unsigned long)addr
));
247 EXPORT_SYMBOL(iounmap
);
249 int map_page(unsigned long va
, phys_addr_t pa
, int flags
)
255 /* Use upper 10 bits of VA to index the first level map */
256 pd
= pmd_offset(pud_offset(pgd_offset_k(va
), va
), va
);
257 /* Use middle 10 bits of VA to index the second-level map */
258 pg
= pte_alloc_kernel(pd
, va
);
261 /* The PTE should never be already set nor present in the
264 BUG_ON(pte_val(*pg
) & (_PAGE_PRESENT
| _PAGE_HASHPTE
));
265 set_pte_at(&init_mm
, va
, pg
, pfn_pte(pa
>> PAGE_SHIFT
,
272 * Map in a big chunk of physical memory starting at KERNELBASE.
274 void __init
mapin_ram(void)
276 unsigned long v
, s
, f
;
282 p
= memstart_addr
+ s
;
283 for (; s
< total_lowmem
; s
+= PAGE_SIZE
) {
284 ktext
= ((char *) v
>= _stext
&& (char *) v
< etext
);
285 f
= ktext
?_PAGE_RAM_TEXT
: _PAGE_RAM
;
287 #ifdef CONFIG_PPC_STD_MMU_32
289 hash_preload(&init_mm
, v
, 0, 0x300);
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 #ifdef CONFIG_DEBUG_PAGEALLOC
332 static int __change_page_attr(struct page
*page
, pgprot_t prot
)
336 unsigned long address
;
338 BUG_ON(PageHighMem(page
));
339 address
= (unsigned long)page_address(page
);
341 if (v_mapped_by_bats(address
) || v_mapped_by_tlbcam(address
))
343 if (!get_pteptr(&init_mm
, address
, &kpte
, &kpmd
))
345 set_pte_at(&init_mm
, address
, kpte
, mk_pte(page
, prot
));
347 #ifdef CONFIG_PPC_STD_MMU
348 flush_hash_pages(0, address
, pmd_val(*kpmd
), 1);
350 flush_tlb_page(NULL
, address
);
358 * Change the page attributes of an page in the linear mapping.
360 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY
362 static int change_page_attr(struct page
*page
, int numpages
, pgprot_t prot
)
367 local_irq_save(flags
);
368 for (i
= 0; i
< numpages
; i
++, page
++) {
369 err
= __change_page_attr(page
, prot
);
373 local_irq_restore(flags
);
378 void kernel_map_pages(struct page
*page
, int numpages
, int enable
)
380 if (PageHighMem(page
))
383 change_page_attr(page
, numpages
, enable
? PAGE_KERNEL
: __pgprot(0));
385 #endif /* CONFIG_DEBUG_PAGEALLOC */
388 unsigned long FIXADDR_TOP
= 0xfffff000;
389 EXPORT_SYMBOL(FIXADDR_TOP
);
391 void __set_fixmap (enum fixed_addresses idx
, phys_addr_t phys
, pgprot_t flags
)
393 unsigned long address
= __fix_to_virt(idx
);
395 if (idx
>= __end_of_fixed_addresses
) {
400 map_page(address
, phys
, pgprot_val(flags
));
404 void __this_fixmap_does_not_exist(void)