arch/loongarch/mm/tlb.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
   4  */
   5 #include <linux/init.h>
   6 #include <linux/sched.h>
   7 #include <linux/smp.h>
   8 #include <linux/mm.h>
   9 #include <linux/hugetlb.h>
  10 #include <linux/export.h>
  11
  12 #include <asm/cpu.h>
  13 #include <asm/bootinfo.h>
  14 #include <asm/mmu_context.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/tlb.h>
  17
  18 void local_flush_tlb_all(void)
  19 {
  20         invtlb_all(INVTLB_CURRENT_ALL, 0, 0);
  21 }
  22 EXPORT_SYMBOL(local_flush_tlb_all);
  23
  24 void local_flush_tlb_user(void)
  25 {
  26         invtlb_all(INVTLB_CURRENT_GFALSE, 0, 0);
  27 }
  28 EXPORT_SYMBOL(local_flush_tlb_user);
  29
  30 void local_flush_tlb_kernel(void)
  31 {
  32         invtlb_all(INVTLB_CURRENT_GTRUE, 0, 0);
  33 }
  34 EXPORT_SYMBOL(local_flush_tlb_kernel);
  35
  36 /*
  37  * All entries common to a mm share an asid. To effectively flush
  38  * these entries, we just bump the asid.
  39  */
  40 void local_flush_tlb_mm(struct mm_struct *mm)
  41 {
  42         int cpu;
  43
  44         preempt_disable();
  45
  46         cpu = smp_processor_id();
  47
  48         if (asid_valid(mm, cpu))
  49                 drop_mmu_context(mm, cpu);
  50         else
  51                 cpumask_clear_cpu(cpu, mm_cpumask(mm));
  52
  53         preempt_enable();
  54 }
  55
  56 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  57         unsigned long end)
  58 {
  59         struct mm_struct *mm = vma->vm_mm;
  60         int cpu = smp_processor_id();
  61
  62         if (asid_valid(mm, cpu)) {
  63                 unsigned long size, flags;
  64
  65                 local_irq_save(flags);
  66                 start = round_down(start, PAGE_SIZE << 1);
  67                 end = round_up(end, PAGE_SIZE << 1);
  68                 size = (end - start) >> (PAGE_SHIFT + 1);
  69                 if (size <= (current_cpu_data.tlbsizestlbsets ?
  70                              current_cpu_data.tlbsize / 8 :
  71                              current_cpu_data.tlbsize / 2)) {
  72                         int asid = cpu_asid(cpu, mm);
  73
  74                         while (start < end) {
  75                                 invtlb(INVTLB_ADDR_GFALSE_AND_ASID, asid, start);
  76                                 start += (PAGE_SIZE << 1);
  77                         }
  78                 } else {
  79                         drop_mmu_context(mm, cpu);
  80                 }
  81                 local_irq_restore(flags);
  82         } else {
  83                 cpumask_clear_cpu(cpu, mm_cpumask(mm));
  84         }
  85 }
  86
  87 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
  88 {
  89         unsigned long size, flags;
  90
  91         local_irq_save(flags);
  92         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
  93         size = (size + 1) >> 1;
  94         if (size <= (current_cpu_data.tlbsizestlbsets ?
  95                      current_cpu_data.tlbsize / 8 :
  96                      current_cpu_data.tlbsize / 2)) {
  97
  98                 start &= (PAGE_MASK << 1);
  99                 end += ((PAGE_SIZE << 1) - 1);
 100                 end &= (PAGE_MASK << 1);
 101
 102                 while (start < end) {
 103                         invtlb_addr(INVTLB_ADDR_GTRUE_OR_ASID, 0, start);
 104                         start += (PAGE_SIZE << 1);
 105                 }
 106         } else {
 107                 local_flush_tlb_kernel();
 108         }
 109         local_irq_restore(flags);
 110 }
 111
 112 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 113 {
 114         int cpu = smp_processor_id();
 115
 116         if (asid_valid(vma->vm_mm, cpu)) {
 117                 int newpid;
 118
 119                 newpid = cpu_asid(cpu, vma->vm_mm);
 120                 page &= (PAGE_MASK << 1);
 121                 invtlb(INVTLB_ADDR_GFALSE_AND_ASID, newpid, page);
 122         } else {
 123                 cpumask_clear_cpu(cpu, mm_cpumask(vma->vm_mm));
 124         }
 125 }
 126
 127 /*
 128  * This one is only used for pages with the global bit set so we don't care
 129  * much about the ASID.
 130  */
 131 void local_flush_tlb_one(unsigned long page)
 132 {
 133         page &= (PAGE_MASK << 1);
 134         invtlb_addr(INVTLB_ADDR_GTRUE_OR_ASID, 0, page);
 135 }
 136
 137 static void __update_hugetlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
 138 {
 139 #ifdef CONFIG_HUGETLB_PAGE
 140         int idx;
 141         unsigned long lo;
 142         unsigned long flags;
 143
 144         local_irq_save(flags);
 145
 146         address &= (PAGE_MASK << 1);
 147         write_csr_entryhi(address);
 148         tlb_probe();
 149         idx = read_csr_tlbidx();
 150         write_csr_pagesize(PS_HUGE_SIZE);
 151         lo = pmd_to_entrylo(pte_val(*ptep));
 152         write_csr_entrylo0(lo);
 153         write_csr_entrylo1(lo + (HPAGE_SIZE >> 1));
 154
 155         if (idx < 0)
 156                 tlb_write_random();
 157         else
 158                 tlb_write_indexed();
 159         write_csr_pagesize(PS_DEFAULT_SIZE);
 160
 161         local_irq_restore(flags);
 162 #endif
 163 }
 164
 165 void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
 166 {
 167         int idx;
 168         unsigned long flags;
 169
 170         /*
 171          * Handle debugger faulting in for debugee.
 172          */
 173         if (current->active_mm != vma->vm_mm)
 174                 return;
 175
 176         if (pte_val(*ptep) & _PAGE_HUGE) {
 177                 __update_hugetlb(vma, address, ptep);
 178                 return;
 179         }
 180
 181         local_irq_save(flags);
 182
 183         if ((unsigned long)ptep & sizeof(pte_t))
 184                 ptep--;
 185
 186         address &= (PAGE_MASK << 1);
 187         write_csr_entryhi(address);
 188         tlb_probe();
 189         idx = read_csr_tlbidx();
 190         write_csr_pagesize(PS_DEFAULT_SIZE);
 191         write_csr_entrylo0(pte_val(*ptep++));
 192         write_csr_entrylo1(pte_val(*ptep));
 193         if (idx < 0)
 194                 tlb_write_random();
 195         else
 196                 tlb_write_indexed();
 197
 198         local_irq_restore(flags);
 199 }
 200
 201 static void setup_ptwalker(void)
 202 {
 203         unsigned long pwctl0, pwctl1;
 204         unsigned long pgd_i = 0, pgd_w = 0;
 205         unsigned long pud_i = 0, pud_w = 0;
 206         unsigned long pmd_i = 0, pmd_w = 0;
 207         unsigned long pte_i = 0, pte_w = 0;
 208
 209         pgd_i = PGDIR_SHIFT;
 210         pgd_w = PAGE_SHIFT - 3;
 211 #if CONFIG_PGTABLE_LEVELS > 3
 212         pud_i = PUD_SHIFT;
 213         pud_w = PAGE_SHIFT - 3;
 214 #endif
 215 #if CONFIG_PGTABLE_LEVELS > 2
 216         pmd_i = PMD_SHIFT;
 217         pmd_w = PAGE_SHIFT - 3;
 218 #endif
 219         pte_i = PAGE_SHIFT;
 220         pte_w = PAGE_SHIFT - 3;
 221
 222         pwctl0 = pte_i | pte_w << 5 | pmd_i << 10 | pmd_w << 15 | pud_i << 20 | pud_w << 25;
 223         pwctl1 = pgd_i | pgd_w << 6;
 224
 225         csr_write64(pwctl0, LOONGARCH_CSR_PWCTL0);
 226         csr_write64(pwctl1, LOONGARCH_CSR_PWCTL1);
 227         csr_write64((long)swapper_pg_dir, LOONGARCH_CSR_PGDH);
 228         csr_write64((long)invalid_pg_dir, LOONGARCH_CSR_PGDL);
 229         csr_write64((long)smp_processor_id(), LOONGARCH_CSR_TMID);
 230 }
 231
 232 static void output_pgtable_bits_defines(void)
 233 {
 234 #define pr_define(fmt, ...)                                     \
 235         pr_debug("#define " fmt, ##__VA_ARGS__)
 236
 237         pr_debug("#include <asm/asm.h>\n");
 238         pr_debug("#include <asm/regdef.h>\n");
 239         pr_debug("\n");
 240
 241         pr_define("_PAGE_VALID_SHIFT %d\n", _PAGE_VALID_SHIFT);
 242         pr_define("_PAGE_DIRTY_SHIFT %d\n", _PAGE_DIRTY_SHIFT);
 243         pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
 244         pr_define("_PAGE_GLOBAL_SHIFT %d\n", _PAGE_GLOBAL_SHIFT);
 245         pr_define("_PAGE_PRESENT_SHIFT %d\n", _PAGE_PRESENT_SHIFT);
 246         pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
 247         pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
 248         pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
 249         pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT);
 250         pr_debug("\n");
 251 }
 252
 253 #ifdef CONFIG_NUMA
 254 unsigned long pcpu_handlers[NR_CPUS];
 255 #endif
 256 extern long exception_handlers[VECSIZE * 128 / sizeof(long)];
 257
 258 void setup_tlb_handler(int cpu)
 259 {
 260         setup_ptwalker();
 261         local_flush_tlb_all();
 262
 263         /* The tlb handlers are generated only once */
 264         if (cpu == 0) {
 265                 memcpy((void *)tlbrentry, handle_tlb_refill, 0x80);
 266                 local_flush_icache_range(tlbrentry, tlbrentry + 0x80);
 267                 set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load, VECSIZE);
 268                 set_handler(EXCCODE_TLBL * VECSIZE, handle_tlb_load, VECSIZE);
 269                 set_handler(EXCCODE_TLBS * VECSIZE, handle_tlb_store, VECSIZE);
 270                 set_handler(EXCCODE_TLBM * VECSIZE, handle_tlb_modify, VECSIZE);
 271                 set_handler(EXCCODE_TLBNR * VECSIZE, handle_tlb_protect, VECSIZE);
 272                 set_handler(EXCCODE_TLBNX * VECSIZE, handle_tlb_protect, VECSIZE);
 273                 set_handler(EXCCODE_TLBPE * VECSIZE, handle_tlb_protect, VECSIZE);
 274         }
 275 #ifdef CONFIG_NUMA
 276         else {
 277                 void *addr;
 278                 struct page *page;
 279                 const int vec_sz = sizeof(exception_handlers);
 280
 281                 if (pcpu_handlers[cpu])
 282                         return;
 283
 284                 page = alloc_pages_node(cpu_to_node(cpu), GFP_ATOMIC, get_order(vec_sz));
 285                 if (!page)
 286                         return;
 287
 288                 addr = page_address(page);
 289                 pcpu_handlers[cpu] = (unsigned long)addr;
 290                 memcpy((void *)addr, (void *)eentry, vec_sz);
 291                 local_flush_icache_range((unsigned long)addr, (unsigned long)addr + vec_sz);
 292                 csr_write64(pcpu_handlers[cpu], LOONGARCH_CSR_EENTRY);
 293                 csr_write64(pcpu_handlers[cpu], LOONGARCH_CSR_MERRENTRY);
 294                 csr_write64(pcpu_handlers[cpu] + 80*VECSIZE, LOONGARCH_CSR_TLBRENTRY);
 295         }
 296 #endif
 297 }
 298
 299 void tlb_init(int cpu)
 300 {
 301         write_csr_pagesize(PS_DEFAULT_SIZE);
 302         write_csr_stlbpgsize(PS_DEFAULT_SIZE);
 303         write_csr_tlbrefill_pagesize(PS_DEFAULT_SIZE);
 304
 305         setup_tlb_handler(cpu);
 306         output_pgtable_bits_defines();
 307 }