arch/hexagon/include/asm/mmu_context.h

   1 /*
   2  * MM context support for the Hexagon architecture
   3  *
   4  * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 and
   8  * only version 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA.
  19  */
  20
  21 #ifndef _ASM_MMU_CONTEXT_H
  22 #define _ASM_MMU_CONTEXT_H
  23
  24 #include <linux/mm_types.h>
  25
  26 #include <asm/setup.h>
  27 #include <asm/page.h>
  28 #include <asm/pgalloc.h>
  29 #include <asm/mem-layout.h>
  30
  31 static inline void destroy_context(struct mm_struct *mm)
  32 {
  33 }
  34
  35 /*
  36  * VM port hides all TLB management, so "lazy TLB" isn't very
  37  * meaningful.  Even for ports to architectures with visble TLBs,
  38  * this is almost invariably a null function.
  39  */
  40 static inline void enter_lazy_tlb(struct mm_struct *mm,
  41         struct task_struct *tsk)
  42 {
  43 }
  44
  45 /*
  46  * Architecture-specific actions, if any, for memory map deactivation.
  47  */
  48 static inline void deactivate_mm(struct task_struct *tsk,
  49         struct mm_struct *mm)
  50 {
  51 }
  52
  53 /**
  54  * init_new_context - initialize context related info for new mm_struct instance
  55  * @tsk: pointer to a task struct
  56  * @mm: pointer to a new mm struct
  57  */
  58 static inline int init_new_context(struct task_struct *tsk,
  59                                         struct mm_struct *mm)
  60 {
  61         /* mm->context is set up by pgd_alloc */
  62         return 0;
  63 }
  64
  65 /*
  66  *  Switch active mm context
  67  */
  68 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  69                                 struct task_struct *tsk)
  70 {
  71         int l1;
  72
  73         /*
  74          * For virtual machine, we have to update system map if it's been
  75          * touched.
  76          */
  77         if (next->context.generation < prev->context.generation) {
  78                 for (l1 = MIN_KERNEL_SEG; l1 <= max_kernel_seg; l1++)
  79                         next->pgd[l1] = init_mm.pgd[l1];
  80
  81                 next->context.generation = prev->context.generation;
  82         }
  83
  84         __vmnewmap((void *)next->context.ptbase);
  85 }
  86
  87 /*
  88  *  Activate new memory map for task
  89  */
  90 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  91 {
  92         unsigned long flags;
  93
  94         local_irq_save(flags);
  95         switch_mm(prev, next, current_thread_info()->task);
  96         local_irq_restore(flags);
  97 }
  98
  99 /*  Generic hooks for arch_dup_mmap and arch_exit_mmap  */
 100 #include <asm-generic/mm_hooks.h>
 101
 102 #endif