arch/arm/kernel/smp_tlb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/arch/arm/kernel/smp_tlb.c
   4  *
   5  *  Copyright (C) 2002 ARM Limited, All Rights Reserved.
   6  */
   7 #include <linux/preempt.h>
   8 #include <linux/smp.h>
   9 #include <linux/uaccess.h>
  10
  11 #include <asm/smp_plat.h>
  12 #include <asm/tlbflush.h>
  13 #include <asm/mmu_context.h>
  14
  15 /**********************************************************************/
  16
  17 /*
  18  * TLB operations
  19  */
  20 struct tlb_args {
  21         struct vm_area_struct *ta_vma;
  22         unsigned long ta_start;
  23         unsigned long ta_end;
  24 };
  25
  26 static inline void ipi_flush_tlb_all(void *ignored)
  27 {
  28         local_flush_tlb_all();
  29 }
  30
  31 static inline void ipi_flush_tlb_mm(void *arg)
  32 {
  33         struct mm_struct *mm = (struct mm_struct *)arg;
  34
  35         local_flush_tlb_mm(mm);
  36 }
  37
  38 static inline void ipi_flush_tlb_page(void *arg)
  39 {
  40         struct tlb_args *ta = (struct tlb_args *)arg;
  41         unsigned int __ua_flags = uaccess_save_and_enable();
  42
  43         local_flush_tlb_page(ta->ta_vma, ta->ta_start);
  44
  45         uaccess_restore(__ua_flags);
  46 }
  47
  48 static inline void ipi_flush_tlb_kernel_page(void *arg)
  49 {
  50         struct tlb_args *ta = (struct tlb_args *)arg;
  51
  52         local_flush_tlb_kernel_page(ta->ta_start);
  53 }
  54
  55 static inline void ipi_flush_tlb_range(void *arg)
  56 {
  57         struct tlb_args *ta = (struct tlb_args *)arg;
  58         unsigned int __ua_flags = uaccess_save_and_enable();
  59
  60         local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);
  61
  62         uaccess_restore(__ua_flags);
  63 }
  64
  65 static inline void ipi_flush_tlb_kernel_range(void *arg)
  66 {
  67         struct tlb_args *ta = (struct tlb_args *)arg;
  68
  69         local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end);
  70 }
  71
  72 static inline void ipi_flush_bp_all(void *ignored)
  73 {
  74         local_flush_bp_all();
  75 }
  76
  77 #ifdef CONFIG_ARM_ERRATA_798181
  78 bool (*erratum_a15_798181_handler)(void);
  79
  80 static bool erratum_a15_798181_partial(void)
  81 {
  82         asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (0));
  83         dsb(ish);
  84         return false;
  85 }
  86
  87 static bool erratum_a15_798181_broadcast(void)
  88 {
  89         asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (0));
  90         dsb(ish);
  91         return true;
  92 }
  93
  94 void erratum_a15_798181_init(void)
  95 {
  96         unsigned int midr = read_cpuid_id();
  97         unsigned int revidr = read_cpuid(CPUID_REVIDR);
  98
  99         /* Brahma-B15 r0p0..r0p2 affected
 100          * Cortex-A15 r0p0..r3p3 w/o ECO fix affected
 101          * Fixes applied to A15 with respect to the revision and revidr are:
 102          *
 103          * r0p0-r2p1: No fixes applied
 104          * r2p2,r2p3:
 105          *      REVIDR[4]: 798181 Moving a virtual page that is being accessed
 106          *                 by an active process can lead to unexpected behavior
 107          *      REVIDR[9]: Not defined
 108          * r2p4,r3p0,r3p1,r3p2:
 109          *      REVIDR[4]: 798181 Moving a virtual page that is being accessed
 110          *                 by an active process can lead to unexpected behavior
 111          *      REVIDR[9]: 798181 Moving a virtual page that is being accessed
 112          *                 by an active process can lead to unexpected behavior
 113          *                 - This is an update to a previously released ECO.
 114          * r3p3:
 115          *      REVIDR[4]: Reserved
 116          *      REVIDR[9]: 798181 Moving a virtual page that is being accessed
 117          *                 by an active process can lead to unexpected behavior
 118          *                 - This is an update to a previously released ECO.
 119          *
 120          * Handling:
 121          *      REVIDR[9] set -> No WA
 122          *      REVIDR[4] set, REVIDR[9] cleared -> Partial WA
 123          *      Both cleared -> Full WA
 124          */
 125         if ((midr & 0xff0ffff0) == 0x420f00f0 && midr <= 0x420f00f2) {
 126                 erratum_a15_798181_handler = erratum_a15_798181_broadcast;
 127         } else if ((midr & 0xff0ffff0) == 0x410fc0f0 && midr < 0x412fc0f2) {
 128                 erratum_a15_798181_handler = erratum_a15_798181_broadcast;
 129         } else if ((midr & 0xff0ffff0) == 0x410fc0f0 && midr < 0x412fc0f4) {
 130                 if (revidr & 0x10)
 131                         erratum_a15_798181_handler =
 132                                 erratum_a15_798181_partial;
 133                 else
 134                         erratum_a15_798181_handler =
 135                                 erratum_a15_798181_broadcast;
 136         } else if ((midr & 0xff0ffff0) == 0x410fc0f0 && midr < 0x413fc0f3) {
 137                 if ((revidr & 0x210) == 0)
 138                         erratum_a15_798181_handler =
 139                                 erratum_a15_798181_broadcast;
 140                 else if (revidr & 0x10)
 141                         erratum_a15_798181_handler =
 142                                 erratum_a15_798181_partial;
 143         } else if ((midr & 0xff0ffff0) == 0x410fc0f0 && midr < 0x414fc0f0) {
 144                 if ((revidr & 0x200) == 0)
 145                         erratum_a15_798181_handler =
 146                                 erratum_a15_798181_partial;
 147         }
 148 }
 149 #endif
 150
 151 static void ipi_flush_tlb_a15_erratum(void *arg)
 152 {
 153         dmb();
 154 }
 155
 156 static void broadcast_tlb_a15_erratum(void)
 157 {
 158         if (!erratum_a15_798181())
 159                 return;
 160
 161         smp_call_function(ipi_flush_tlb_a15_erratum, NULL, 1);
 162 }
 163
 164 static void broadcast_tlb_mm_a15_erratum(struct mm_struct *mm)
 165 {
 166         int this_cpu;
 167         cpumask_t mask = { CPU_BITS_NONE };
 168
 169         if (!erratum_a15_798181())
 170                 return;
 171
 172         this_cpu = get_cpu();
 173         a15_erratum_get_cpumask(this_cpu, mm, &mask);
 174         smp_call_function_many(&mask, ipi_flush_tlb_a15_erratum, NULL, 1);
 175         put_cpu();
 176 }
 177
 178 void flush_tlb_all(void)
 179 {
 180         if (tlb_ops_need_broadcast())
 181                 on_each_cpu(ipi_flush_tlb_all, NULL, 1);
 182         else
 183                 __flush_tlb_all();
 184         broadcast_tlb_a15_erratum();
 185 }
 186
 187 void flush_tlb_mm(struct mm_struct *mm)
 188 {
 189         if (tlb_ops_need_broadcast())
 190                 on_each_cpu_mask(mm_cpumask(mm), ipi_flush_tlb_mm, mm, 1);
 191         else
 192                 __flush_tlb_mm(mm);
 193         broadcast_tlb_mm_a15_erratum(mm);
 194 }
 195
 196 void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
 197 {
 198         if (tlb_ops_need_broadcast()) {
 199                 struct tlb_args ta;
 200                 ta.ta_vma = vma;
 201                 ta.ta_start = uaddr;
 202                 on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_page,
 203                                         &ta, 1);
 204         } else
 205                 __flush_tlb_page(vma, uaddr);
 206         broadcast_tlb_mm_a15_erratum(vma->vm_mm);
 207 }
 208
 209 void flush_tlb_kernel_page(unsigned long kaddr)
 210 {
 211         if (tlb_ops_need_broadcast()) {
 212                 struct tlb_args ta;
 213                 ta.ta_start = kaddr;
 214                 on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1);
 215         } else
 216                 __flush_tlb_kernel_page(kaddr);
 217         broadcast_tlb_a15_erratum();
 218 }
 219
 220 void flush_tlb_range(struct vm_area_struct *vma,
 221                      unsigned long start, unsigned long end)
 222 {
 223         if (tlb_ops_need_broadcast()) {
 224                 struct tlb_args ta;
 225                 ta.ta_vma = vma;
 226                 ta.ta_start = start;
 227                 ta.ta_end = end;
 228                 on_each_cpu_mask(mm_cpumask(vma->vm_mm), ipi_flush_tlb_range,
 229                                         &ta, 1);
 230         } else
 231                 local_flush_tlb_range(vma, start, end);
 232         broadcast_tlb_mm_a15_erratum(vma->vm_mm);
 233 }
 234
 235 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 236 {
 237         if (tlb_ops_need_broadcast()) {
 238                 struct tlb_args ta;
 239                 ta.ta_start = start;
 240                 ta.ta_end = end;
 241                 on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
 242         } else
 243                 local_flush_tlb_kernel_range(start, end);
 244         broadcast_tlb_a15_erratum();
 245 }
 246
 247 void flush_bp_all(void)
 248 {
 249         if (tlb_ops_need_broadcast())
 250                 on_each_cpu(ipi_flush_bp_all, NULL, 1);
 251         else
 252                 __flush_bp_all();
 253 }