nfsd: don't fail unchecked creates of non-special files
[zen-stable.git] / arch / microblaze / mm / mmu_context.c
blob26ff82f4fa8f77fd48701b9f6ae7cea2467c0738
1 /*
2 * This file contains the routines for handling the MMU.
4 * Copyright (C) 2007 Xilinx, Inc. All rights reserved.
6 * Derived from arch/ppc/mm/4xx_mmu.c:
7 * -- paulus
9 * Derived from arch/ppc/mm/init.c:
10 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
12 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
13 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
14 * Copyright (C) 1996 Paul Mackerras
15 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
17 * Derived from "arch/i386/mm/init.c"
18 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
27 #include <linux/mm.h>
28 #include <linux/init.h>
30 #include <asm/tlbflush.h>
31 #include <asm/mmu_context.h>
33 mm_context_t next_mmu_context;
34 unsigned long context_map[LAST_CONTEXT / BITS_PER_LONG + 1];
35 atomic_t nr_free_contexts;
36 struct mm_struct *context_mm[LAST_CONTEXT+1];
39 * Initialize the context management stuff.
41 void __init mmu_context_init(void)
44 * The use of context zero is reserved for the kernel.
45 * This code assumes FIRST_CONTEXT < 32.
47 context_map[0] = (1 << FIRST_CONTEXT) - 1;
48 next_mmu_context = FIRST_CONTEXT;
49 atomic_set(&nr_free_contexts, LAST_CONTEXT - FIRST_CONTEXT + 1);
53 * Steal a context from a task that has one at the moment.
55 * This isn't an LRU system, it just frees up each context in
56 * turn (sort-of pseudo-random replacement :). This would be the
57 * place to implement an LRU scheme if anyone were motivated to do it.
59 void steal_context(void)
61 struct mm_struct *mm;
63 /* free up context `next_mmu_context' */
64 /* if we shouldn't free context 0, don't... */
65 if (next_mmu_context < FIRST_CONTEXT)
66 next_mmu_context = FIRST_CONTEXT;
67 mm = context_mm[next_mmu_context];
68 flush_tlb_mm(mm);
69 destroy_context(mm);