[PATCH] backlight: HP Jornada 680 Backlight driver updates/fixes
[linux-2.6-block.git] / include / asm-powerpc / mmu_context.h
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1#ifndef __ASM_POWERPC_MMU_CONTEXT_H
2#define __ASM_POWERPC_MMU_CONTEXT_H
88ced031 3#ifdef __KERNEL__
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4
5#ifndef CONFIG_PPC64
6#include <asm-ppc/mmu_context.h>
7#else
1da177e4 8
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9#include <linux/kernel.h>
10#include <linux/mm.h>
11#include <asm/mmu.h>
12#include <asm/cputable.h>
13
14/*
15 * Copyright (C) 2001 PPC 64 Team, IBM Corp
16 *
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
21 */
22
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23/*
24 * Getting into a kernel thread, there is no valid user segment, mark
25 * paca->pgdir NULL so that SLB miss on user addresses will fault
26 */
27static inline void enter_lazy_tlb(struct mm_struct *mm,
28 struct task_struct *tsk)
1da177e4 29{
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30#ifdef CONFIG_PPC_64K_PAGES
31 get_paca()->pgdir = NULL;
32#endif /* CONFIG_PPC_64K_PAGES */
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33}
34
35#define NO_CONTEXT 0
36#define MAX_CONTEXT (0x100000-1)
37
38extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
39extern void destroy_context(struct mm_struct *mm);
40
41extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
42extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
43
44/*
45 * switch_mm is the entry point called from the architecture independent
46 * code in kernel/sched.c
47 */
48static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
49 struct task_struct *tsk)
50{
51 if (!cpu_isset(smp_processor_id(), next->cpu_vm_mask))
52 cpu_set(smp_processor_id(), next->cpu_vm_mask);
53
54 /* No need to flush userspace segments if the mm doesnt change */
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55#ifdef CONFIG_PPC_64K_PAGES
56 if (prev == next && get_paca()->pgdir == next->pgd)
57 return;
58#else
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59 if (prev == next)
60 return;
3c726f8d 61#endif /* CONFIG_PPC_64K_PAGES */
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62
63#ifdef CONFIG_ALTIVEC
64 if (cpu_has_feature(CPU_FTR_ALTIVEC))
65 asm volatile ("dssall");
66#endif /* CONFIG_ALTIVEC */
67
68 if (cpu_has_feature(CPU_FTR_SLB))
69 switch_slb(tsk, next);
70 else
71 switch_stab(tsk, next);
72}
73
74#define deactivate_mm(tsk,mm) do { } while (0)
75
76/*
77 * After we have set current->mm to a new value, this activates
78 * the context for the new mm so we see the new mappings.
79 */
80static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
81{
82 unsigned long flags;
83
84 local_irq_save(flags);
85 switch_mm(prev, next, current);
86 local_irq_restore(flags);
87}
88
047ea784 89#endif /* CONFIG_PPC64 */
88ced031 90#endif /* __KERNEL__ */
047ea784 91#endif /* __ASM_POWERPC_MMU_CONTEXT_H */