include/asm-mips/mmu_context.h

   1 /* $Id: mmu_context.h,v 1.3 1998/10/16 19:22:54 ralf Exp $
   2  *
   3  * Switch a MMU context.
   4  *
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License.  See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  *
   9  * Copyright (C) 1996, 1997, 1998 by Ralf Baechle
  10  */
  11 #ifndef __ASM_MIPS_MMU_CONTEXT_H
  12 #define __ASM_MIPS_MMU_CONTEXT_H
  13
  14 /* Fuck.  The f-word is here so you can grep for it :-)  */
  15 extern unsigned long asid_cache;
  16
  17 /* I patch, therefore I am ...  */
  18 #define ASID_INC(asid)                                          \
  19  ({ unsigned long __asid = asid;                                \
  20    __asm__("1:\taddiu\t%0,0\t\t\t\t# patched\n\t"               \
  21            ".section\t__asid_inc,\"a\"\n\t"                     \
  22            ".word\t1b\n\t"                                      \
  23            ".previous"                                          \
  24            :"=r" (__asid)                                       \
  25            :"0" (__asid));                                      \
  26    __asid; })
  27 #define ASID_MASK(asid)                                         \
  28  ({ unsigned long __asid = asid;                                \
  29    __asm__("1:\tandi\t%0,%1,0\t\t\t# patched\n\t"                       \
  30            ".section\t__asid_mask,\"a\"\n\t"                    \
  31            ".word\t1b\n\t"                                      \
  32            ".previous"                                          \
  33            :"=r" (__asid)                                       \
  34            :"r" (__asid));                                      \
  35    __asid; })
  36 #define ASID_VERSION_MASK                                       \
  37  ({ unsigned long __asid;                                       \
  38    __asm__("1:\tli\t%0,0\t\t\t\t# patched\n\t"                  \
  39            ".section\t__asid_version_mask,\"a\"\n\t"            \
  40            ".word\t1b\n\t"                                      \
  41            ".previous"                                          \
  42            :"=r" (__asid));                                     \
  43    __asid; })
  44 #define ASID_FIRST_VERSION                                      \
  45  ({ unsigned long __asid = asid;                                \
  46    __asm__("1:\tli\t%0,0\t\t\t\t# patched\n\t"                  \
  47            ".section\t__asid_first_version,\"a\"\n\t"           \
  48            ".word\t1b\n\t"                                      \
  49            ".previous"                                          \
  50            :"=r" (__asid));                                     \
  51    __asid; })
  52
  53 #define ASID_FIRST_VERSION_R3000 0x1000
  54 #define ASID_FIRST_VERSION_R4000 0x100
  55
  56 extern inline void
  57 get_new_mmu_context(struct mm_struct *mm, unsigned long asid)
  58 {
  59         if (!ASID_MASK((asid = ASID_INC(asid)))) {
  60                 flush_tlb_all(); /* start new asid cycle */
  61                 if (!asid)      /* fix version if needed */
  62                         asid = ASID_FIRST_VERSION;
  63         }
  64         mm->context = asid_cache = asid;
  65 }
  66
  67 extern inline void
  68 get_mmu_context(struct task_struct *p)
  69 {
  70         struct mm_struct *mm = p->mm;
  71
  72         if (mm) {
  73                 unsigned long asid = asid_cache;
  74                 /* Check if our ASID is of an older version and thus invalid */
  75                 if ((mm->context ^ asid) & ASID_VERSION_MASK)
  76                         get_new_mmu_context(mm, asid);
  77         }
  78 }
  79
  80 /*
  81  * Initialize the context related info for a new mm_struct
  82  * instance.
  83  */
  84 extern inline void init_new_context(struct mm_struct *mm)
  85 {
  86         mm->context = 0;
  87 }
  88
  89 /*
  90  * Destroy context related info for an mm_struct that is about
  91  * to be put to rest.
  92  */
  93 extern inline void destroy_context(struct mm_struct *mm)
  94 {
  95         mm->context = 0;
  96 }
  97
  98 /*
  99  * After we have set current->mm to a new value, this activates
 100  * the context for the new mm so we see the new mappings.
 101  */
 102 extern inline void activate_context(struct task_struct *tsk)
 103 {
 104         get_mmu_context(tsk);
 105         set_entryhi(tsk->mm->context);
 106 }
 107
 108 extern void __asid_setup(unsigned int inc, unsigned int mask,
 109                          unsigned int version_mask, unsigned int first_version);
 110
 111 extern inline void r3000_asid_setup(void)
 112 {
 113         __asid_setup(0x40, 0xfc0, 0xf000, ASID_FIRST_VERSION_R3000);
 114 }
 115
 116 extern inline void r6000_asid_setup(void)
 117 {
 118         panic("r6000_asid_setup: implement me");        /* No idea ...  */
 119 }
 120
 121 extern inline void tfp_asid_setup(void)
 122 {
 123         panic("tfp_asid_setup: implement me");  /* No idea ...  */
 124 }
 125
 126 extern inline void r4xx0_asid_setup(void)
 127 {
 128         __asid_setup(1, 0xff, 0xff00, ASID_FIRST_VERSION_R4000);
 129 }
 130
 131 /* R10000 has the same ASID mechanism as the R4000.  */
 132 #define andes_asid_setup r4xx0_asid_setup
 133
 134 #endif /* __ASM_MIPS_MMU_CONTEXT_H */