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 <asm/setup.h>
  25 #include <asm/page.h>
  26 #include <asm/pgalloc.h>
  27 #include <asm/mem-layout.h>
  28
  29 static inline void destroy_context(struct mm_struct *mm)
  30 {
  31 }
  32
  33 /*
  34  * VM port hides all TLB management, so "lazy TLB" isn't very
  35  * meaningful.  Even for ports to architectures with visble TLBs,
  36  * this is almost invariably a null function.
  37  */
  38 static inline void enter_lazy_tlb(struct mm_struct *mm,
  39         struct task_struct *tsk)
  40 {
  41 }
  42
  43 /*
  44  * Architecture-specific actions, if any, for memory map deactivation.
  45  */
  46 static inline void deactivate_mm(struct task_struct *tsk,
  47         struct mm_struct *mm)
  48 {
  49 }
  50
  51 /**
  52  * init_new_context - initialize context related info for new mm_struct instance
  53  * @tsk: pointer to a task struct
  54  * @mm: pointer to a new mm struct
  55  */
  56 static inline int init_new_context(struct task_struct *tsk,
  57                                         struct mm_struct *mm)
  58 {
  59         /* mm->context is set up by pgd_alloc */
  60         return 0;
  61 }
  62
  63 /*
  64  *  Switch active mm context
  65  */
  66 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  67                                 struct task_struct *tsk)
  68 {
  69         int l1;
  70
  71         /*
  72          * For virtual machine, we have to update system map if it's been
  73          * touched.
  74          */
  75         if (next->context.generation < prev->context.generation) {
  76                 for (l1 = MIN_KERNEL_SEG; l1 <= max_kernel_seg; l1++)
  77                         next->pgd[l1] = init_mm.pgd[l1];
  78
  79                 next->context.generation = prev->context.generation;
  80         }
  81
  82         __vmnewmap((void *)next->context.ptbase);
  83 }
  84
  85 /*
  86  *  Activate new memory map for task
  87  */
  88 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  89 {
  90         unsigned long flags;
  91
  92         local_irq_save(flags);
  93         switch_mm(prev, next, current_thread_info()->task);
  94         local_irq_restore(flags);
  95 }
  96
  97 /*  Generic hooks for arch_dup_mmap and arch_exit_mmap  */
  98 #include <asm-generic/mm_hooks.h>
  99
 100 #endif