arch/arm/kernel/smp_tlb.c

   1 /*
   2  *  linux/arch/arm/kernel/smp_tlb.c
   3  *
   4  *  Copyright (C) 2002 ARM Limited, 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 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/preempt.h>
  11 #include <linux/smp.h>
  12 #include <linux/uaccess.h>
  13
  14 #include <asm/smp_plat.h>
  15 #include <asm/tlbflush.h>
  16 #include <asm/mmu_context.h>
  17
  18 /**********************************************************************/
  19
  20 /*
  21  * TLB operations
  22  */
  23 struct tlb_args {
  24         struct vm_area_struct *ta_vma;
  25         unsigned long ta_start;
  26         unsigned long ta_end;
  27 };
  28
  29 static inline void ipi_flush_tlb_all(void *ignored)
  30 {
  31         local_flush_tlb_all();
  32 }
  33
  34 static inline void ipi_flush_tlb_mm(void *arg)
  35 {
  36         struct mm_struct *mm = (struct mm_struct *)arg;
  37
  38         local_flush_tlb_mm(mm);
  39 }
  40
  41 static inline void ipi_flush_tlb_page(void *arg)
  42 {
  43         struct tlb_args *ta = (struct tlb_args *)arg;
  44         unsigned int __ua_flags = uaccess_save_and_enable();
  45
  46         local_flush_tlb_page(ta->ta_vma, ta->ta_start);
  47
  48         uaccess_restore(__ua_flags);
  49 }
  50
  51 static inline void ipi_flush_tlb_kernel_page(void *arg)
  52 {
  53         struct tlb_args *ta = (struct tlb_args *)arg;
  54
  55         local_flush_tlb_kernel_page(ta->ta_start);
  56 }
  57
  58 static inline void ipi_flush_tlb_range(void *arg)
  59 {
  60         struct tlb_args *ta = (struct tlb_args *)arg;
  61         unsigned int __ua_flags = uaccess_save_and_enable();
  62
  63         local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);
  64
  65         uaccess_restore(__ua_flags);
  66 }
  67
  68 static inline void ipi_flush_tlb_kernel_range(void *arg)
  69 {
  70         struct tlb_args *ta = (struct tlb_args *)arg;
  71
  72         local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end);
  73 }
  74
  75 static inline void ipi_flush_bp_all(void *ignored)
  76 {
  77         local_flush_bp_all();
  78 }
  79
  80 #ifdef CONFIG_ARM_ERRATA_798181
  81 bool (*erratum_a15_798181_handler)(void);
  82
  83 static bool erratum_a15_798181_partial(void)
  84 {
  85         asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (0));
  86         dsb(ish);
  87         return false;
  88 }
  89
  90 static bool erratum_a15_798181_broadcast(void)
  91 {
  92         asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (0));
  93         dsb(ish);
  94         return true;
  95 }
  96
  97 void erratum_a15_798181_init(void)
  98 {
  99         unsigned int midr = read_cpuid_id();
 100         unsigned int revidr = read_cpuid(CPUID_REVIDR);
 101
 102         /* Brahma-B15 r0p0..r0p2 affected
 103          * Cortex-A15 r0p0..r3p3 w/o ECO fix affected
 104          * Fixes applied to A15 with respect to the revision and revidr are:
 105          *
 106          * r0p0-r2p1: No fixes applied
 107          * r2p2,r2p3:
 108          *      REVIDR[4]: 798181 Moving a virtual page that is being accessed
 109          *                 by an active process can lead to unexpected behavior
 110          *      REVIDR[9]: Not defined
 111          * r2p4,r3p0,r3p1,r3p2:
 112          *      REVIDR[4]: 798181 Moving a virtual page that is being accessed
 113          *                 by an active process can lead to unexpected behavior
 114          *      REVIDR[9]: 798181 Moving a virtual page that is being accessed
 115          *                 by an active process can lead to unexpected behavior
 116          *                 - This is an update to a previously released ECO.
 117          * r3p3:
 118          *      REVIDR[4]: Reserved
 119          *      REVIDR[9]: 798181 Moving a virtual page that is being accessed
 120          *                 by an active process can lead to unexpected behavior
 121          *                 - This is an update to a previously released ECO.
 122          *
 123          * Handling:
 124          *      REVIDR[9] set -> No WA
 125          *      REVIDR[4] set, REVIDR[9] cleared -> Partial WA
 126          *      Both cleared -> Full WA
 127          */
 128         if ((midr & 0xff0ffff0) == 0x420f00f0 && midr <= 0x420f00f2) {
 129                 erratum_a15_798181_handler = erratum_a15_798181_broadcast;
 130         } else if ((midr & 0xff0ffff0) == 0x410fc0f0 && midr < 0x412fc0f2) {
 131                 erratum_a15_798181_handler = erratum_a15_798181_broadcast;
 132         } else if ((midr & 0xff0ffff0) == 0x410fc0f0 && midr < 0x412fc0f4) {
 133                 if (revidr & 0x10)
 134                         erratum_a15_798181_handler =
 135                                 erratum_a15_798181_partial;
 136                 else
 137                         erratum_a15_798181_handler =
 138                                 erratum_a15_798181_broadcast;
 139         } else if ((midr & 0xff0ffff0) == 0x410fc0f0 && midr < 0x413fc0f3) {
 140                 if ((revidr & 0x210) == 0)
 141                         erratum_a15_798181_handler =
 142                                 erratum_a15_798181_broadcast;
 143                 else if (revidr & 0x10)
 144                         erratum_a15_798181_handler =
 145                                 erratum_a15_798181_partial;
 146         } else if ((midr & 0xff0ffff0) == 0x410fc0f0 && midr < 0x414fc0f0) {
 147                 if ((revidr & 0x200) == 0)
 148                         erratum_a15_798181_handler =
 149                                 erratum_a15_798181_partial;
 150         }
 151 }
 152 #endif
 153
 154 static void ipi_flush_tlb_a15_erratum(void *arg)
 155 {
 156         dmb();
 157 }
 158
 159 static void broadcast_tlb_a15_erratum(void)
 160 {
 161         if (!erratum_a15_798181())
 162                 return;
 163
 164         smp_call_function(ipi_flush_tlb_a15_erratum, NULL, 1);
 165 }
 166
 167 static void broadcast_tlb_mm_a15_erratum(struct mm_struct *mm)
 168 {
 169         int this_cpu;
 170         cpumask_t mask = { CPU_BITS_NONE };
 171
 172         if (!erratum_a15_798181())
 173                 return;
 174
 175         this_cpu = get_cpu();
 176         a15_erratum_get_cpumask(this_cpu, mm, &mask);
 177         smp_call_function_many(&mask, ipi_flush_tlb_a15_erratum, NULL, 1);
 178         put_cpu();
 179 }
 180
 181 void flush_tlb_all(void)
 182 {
 183         if (tlb_ops_need_broadcast())
 184                 on_each_cpu(ipi_flush_tlb_all, NULL, 1);
 185         else
 186                 __flush_tlb_all();
 187         broadcast_tlb_a15_erratum();
 188 }
 189
 190 void flush_tlb_mm(struct mm_struct *mm)
 191 {
 192         if (tlb_ops_need_broadcast())
 193                 on_each_cpu_mask(mm_cpumask(mm), ipi_flush_tlb_mm, mm, 1);
 194         else
 195                 __flush_tlb_mm(mm);
 196         broadcast_tlb_mm_a15_erratum(mm);
 197 }
 198
 199 void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
 200 {
 201         if (tlb_ops_need_broadcast()) {
 202                 struct tlb_args ta;
 203                 ta.ta_vma = vma;
 204                 ta.ta_start = uaddr;
 205                 on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_page,
 206                                         &ta, 1);
 207         } else
 208                 __flush_tlb_page(vma, uaddr);
 209         broadcast_tlb_mm_a15_erratum(vma->vm_mm);
 210 }
 211
 212 void flush_tlb_kernel_page(unsigned long kaddr)
 213 {
 214         if (tlb_ops_need_broadcast()) {
 215                 struct tlb_args ta;
 216                 ta.ta_start = kaddr;
 217                 on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1);
 218         } else
 219                 __flush_tlb_kernel_page(kaddr);
 220         broadcast_tlb_a15_erratum();
 221 }
 222
 223 void flush_tlb_range(struct vm_area_struct *vma,
 224                      unsigned long start, unsigned long end)
 225 {
 226         if (tlb_ops_need_broadcast()) {
 227                 struct tlb_args ta;
 228                 ta.ta_vma = vma;
 229                 ta.ta_start = start;
 230                 ta.ta_end = end;
 231                 on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_range,
 232                                         &ta, 1);
 233         } else
 234                 local_flush_tlb_range(vma, start, end);
 235         broadcast_tlb_mm_a15_erratum(vma->vm_mm);
 236 }
 237
 238 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 239 {
 240         if (tlb_ops_need_broadcast()) {
 241                 struct tlb_args ta;
 242                 ta.ta_start = start;
 243                 ta.ta_end = end;
 244                 on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
 245         } else
 246                 local_flush_tlb_kernel_range(start, end);
 247         broadcast_tlb_a15_erratum();
 248 }
 249
 250 void flush_bp_all(void)
 251 {
 252         if (tlb_ops_need_broadcast())
 253                 on_each_cpu(ipi_flush_bp_all, NULL, 1);
 254         else
 255                 __flush_bp_all();
 256 }