include/asm-powerpc/mmu_context.h

   1 #ifndef __ASM_POWERPC_MMU_CONTEXT_H
   2 #define __ASM_POWERPC_MMU_CONTEXT_H
   3 #ifdef __KERNEL__
   4
   5 #ifndef CONFIG_PPC64
   6 #include <asm-ppc/mmu_context.h>
   7 #else
   8
   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
  23 static inline void enter_lazy_tlb(struct mm_struct *mm,
  24                                   struct task_struct *tsk)
  25 {
  26 }
  27
  28 /*
  29  * The proto-VSID space has 2^35 - 1 segments available for user mappings.
  30  * Each segment contains 2^28 bytes.  Each context maps 2^44 bytes,
  31  * so we can support 2^19-1 contexts (19 == 35 + 28 - 44).
  32  */
  33 #define NO_CONTEXT      0
  34 #define MAX_CONTEXT     ((1UL << 19) - 1)
  35
  36 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
  37 extern void destroy_context(struct mm_struct *mm);
  38
  39 extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
  40 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
  41
  42 /*
  43  * switch_mm is the entry point called from the architecture independent
  44  * code in kernel/sched.c
  45  */
  46 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  47                              struct task_struct *tsk)
  48 {
  49         if (!cpu_isset(smp_processor_id(), next->cpu_vm_mask))
  50                 cpu_set(smp_processor_id(), next->cpu_vm_mask);
  51
  52         /* No need to flush userspace segments if the mm doesnt change */
  53         if (prev == next)
  54                 return;
  55
  56 #ifdef CONFIG_ALTIVEC
  57         if (cpu_has_feature(CPU_FTR_ALTIVEC))
  58                 asm volatile ("dssall");
  59 #endif /* CONFIG_ALTIVEC */
  60
  61         if (cpu_has_feature(CPU_FTR_SLB))
  62                 switch_slb(tsk, next);
  63         else
  64                 switch_stab(tsk, next);
  65 }
  66
  67 #define deactivate_mm(tsk,mm)   do { } while (0)
  68
  69 /*
  70  * After we have set current->mm to a new value, this activates
  71  * the context for the new mm so we see the new mappings.
  72  */
  73 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
  74 {
  75         unsigned long flags;
  76
  77         local_irq_save(flags);
  78         switch_mm(prev, next, current);
  79         local_irq_restore(flags);
  80 }
  81
  82 #endif /* CONFIG_PPC64 */
  83 #endif /* __KERNEL__ */
  84 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */