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 */