1 /* MN10300 Page table management
3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Modified by David Howells (dhowells@redhat.com)
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public Licence
9 * as published by the Free Software Foundation; either version
10 * 2 of the Licence, or (at your option) any later version.
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/gfp.h>
17 #include <linux/swap.h>
18 #include <linux/smp.h>
19 #include <linux/highmem.h>
20 #include <linux/pagemap.h>
21 #include <linux/spinlock.h>
22 #include <linux/quicklist.h>
24 #include <asm/pgtable.h>
25 #include <asm/pgalloc.h>
27 #include <asm/tlbflush.h>
30 * Associate a large virtual page frame with a given physical page frame
31 * and protection flags for that frame. pfn is for the base of the page,
32 * vaddr is what the page gets mapped to - both must be properly aligned.
33 * The pmd must already be instantiated. Assumes PAE mode.
35 void set_pmd_pfn(unsigned long vaddr
, unsigned long pfn
, pgprot_t flags
)
41 if (vaddr
& (PMD_SIZE
-1)) { /* vaddr is misaligned */
42 printk(KERN_ERR
"set_pmd_pfn: vaddr misaligned\n");
45 if (pfn
& (PTRS_PER_PTE
-1)) { /* pfn is misaligned */
46 printk(KERN_ERR
"set_pmd_pfn: pfn misaligned\n");
49 pgd
= swapper_pg_dir
+ pgd_index(vaddr
);
51 printk(KERN_ERR
"set_pmd_pfn: pgd_none\n");
54 pud
= pud_offset(pgd
, vaddr
);
55 pmd
= pmd_offset(pud
, vaddr
);
56 set_pmd(pmd
, pfn_pmd(pfn
, flags
));
58 * It's enough to flush this one mapping.
59 * (PGE mappings get flushed as well)
61 local_flush_tlb_one(vaddr
);
64 pte_t
*pte_alloc_one_kernel(struct mm_struct
*mm
, unsigned long address
)
66 pte_t
*pte
= (pte_t
*)__get_free_page(GFP_KERNEL
|__GFP_REPEAT
);
72 struct page
*pte_alloc_one(struct mm_struct
*mm
, unsigned long address
)
77 pte
= alloc_pages(GFP_KERNEL
|__GFP_HIGHMEM
|__GFP_REPEAT
, 0);
79 pte
= alloc_pages(GFP_KERNEL
|__GFP_REPEAT
, 0);
87 * List of all pgd's needed for non-PAE so it can invalidate entries
88 * in both cached and uncached pgd's; not needed for PAE since the
89 * kernel pmd is shared. If PAE were not to share the pmd a similar
90 * tactic would be needed. This is essentially codepath-based locking
91 * against pageattr.c; it is the unique case in which a valid change
92 * of kernel pagetables can't be lazily synchronized by vmalloc faults.
93 * vmalloc faults work because attached pagetables are never freed.
94 * If the locking proves to be non-performant, a ticketing scheme with
95 * checks at dup_mmap(), exec(), and other mmlist addition points
96 * could be used. The locking scheme was chosen on the basis of
97 * manfred's recommendations and having no core impact whatsoever.
100 DEFINE_SPINLOCK(pgd_lock
);
101 struct page
*pgd_list
;
103 static inline void pgd_list_add(pgd_t
*pgd
)
105 struct page
*page
= virt_to_page(pgd
);
106 page
->index
= (unsigned long) pgd_list
;
108 set_page_private(pgd_list
, (unsigned long) &page
->index
);
110 set_page_private(page
, (unsigned long) &pgd_list
);
113 static inline void pgd_list_del(pgd_t
*pgd
)
115 struct page
*next
, **pprev
, *page
= virt_to_page(pgd
);
116 next
= (struct page
*) page
->index
;
117 pprev
= (struct page
**) page_private(page
);
120 set_page_private(next
, (unsigned long) pprev
);
123 void pgd_ctor(void *pgd
)
127 if (PTRS_PER_PMD
== 1)
128 spin_lock_irqsave(&pgd_lock
, flags
);
130 memcpy((pgd_t
*)pgd
+ USER_PTRS_PER_PGD
,
131 swapper_pg_dir
+ USER_PTRS_PER_PGD
,
132 (PTRS_PER_PGD
- USER_PTRS_PER_PGD
) * sizeof(pgd_t
));
134 if (PTRS_PER_PMD
> 1)
138 spin_unlock_irqrestore(&pgd_lock
, flags
);
139 memset(pgd
, 0, USER_PTRS_PER_PGD
* sizeof(pgd_t
));
142 /* never called when PTRS_PER_PMD > 1 */
143 void pgd_dtor(void *pgd
)
145 unsigned long flags
; /* can be called from interrupt context */
147 spin_lock_irqsave(&pgd_lock
, flags
);
149 spin_unlock_irqrestore(&pgd_lock
, flags
);
152 pgd_t
*pgd_alloc(struct mm_struct
*mm
)
154 return quicklist_alloc(0, GFP_KERNEL
, pgd_ctor
);
157 void pgd_free(struct mm_struct
*mm
, pgd_t
*pgd
)
159 quicklist_free(0, pgd_dtor
, pgd
);
162 void __init
pgtable_cache_init(void)
166 void check_pgt_cache(void)
168 quicklist_trim(0, pgd_dtor
, 25, 16);