projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 14cf11af PM |
1 | /* |
| 2 | * MMU context allocation for 64-bit kernels. | |
| 3 | * | |
| 4 | * Copyright (C) 2004 Anton Blanchard, IBM Corp. <anton@samba.org> | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or | |
| 7 | * modify it under the terms of the GNU General Public License | |
| 8 | * as published by the Free Software Foundation; either version | |
| 9 | * 2 of the License, or (at your option) any later version. | |
| 10 | * | |
| 11 | */ | |
| 12 | ||
| 14cf11af PM |
13 | #include <linux/sched.h> |
| 14 | #include <linux/kernel.h> | |
| 15 | #include <linux/errno.h> | |
| 16 | #include <linux/string.h> | |
| 17 | #include <linux/types.h> | |
| 18 | #include <linux/mm.h> | |
| 19 | #include <linux/spinlock.h> | |
| 20 | #include <linux/idr.h> | |
| 21 | ||
| 22 | #include <asm/mmu_context.h> | |
| 23 | ||
| 24 | static DEFINE_SPINLOCK(mmu_context_lock); | |
| 25 | static DEFINE_IDR(mmu_context_idr); | |
| 26 | ||
| 27 | int init_new_context(struct task_struct *tsk, struct mm_struct *mm) | |
| 28 | { | |
| 29 | int index; | |
| 30 | int err; | |
| 31 | ||
| 32 | again: | |
| 33 | if (!idr_pre_get(&mmu_context_idr, GFP_KERNEL)) | |
| 34 | return -ENOMEM; | |
| 35 | ||
| 36 | spin_lock(&mmu_context_lock); | |
| 37 | err = idr_get_new_above(&mmu_context_idr, NULL, 1, &index); | |
| 38 | spin_unlock(&mmu_context_lock); | |
| 39 | ||
| 40 | if (err == -EAGAIN) | |
| 41 | goto again; | |
| 42 | else if (err) | |
| 43 | return err; | |
| 44 | ||
| 45 | if (index > MAX_CONTEXT) { | |
| f86c9747 | 46 | spin_lock(&mmu_context_lock); |
| 14cf11af | 47 | idr_remove(&mmu_context_idr, index); |
| f86c9747 | 48 | spin_unlock(&mmu_context_lock); |
| 14cf11af PM |
49 | return -ENOMEM; |
| 50 | } | |
| 51 | ||
| d0f13e3c BH |
52 | /* The old code would re-promote on fork, we don't do that |
| 53 | * when using slices as it could cause problem promoting slices | |
| 54 | * that have been forced down to 4K | |
| 55 | */ | |
| e8ff0646 | 56 | if (slice_mm_new_context(mm)) |
| d0f13e3c | 57 | slice_set_user_psize(mm, mmu_virtual_psize); |
| 9dfe5c53 | 58 | mm->context.id = index; |
| 14cf11af PM |
59 | |
| 60 | return 0; | |
| 61 | } | |
| 62 | ||
| 63 | void destroy_context(struct mm_struct *mm) | |
| 64 | { | |
| 65 | spin_lock(&mmu_context_lock); | |
| 66 | idr_remove(&mmu_context_idr, mm->context.id); | |
| 67 | spin_unlock(&mmu_context_lock); | |
| 68 | ||
| 69 | mm->context.id = NO_CONTEXT; | |
| 70 | } |