arch/riscv/mm/tlbflush.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <linux/mm.h>
   4 #include <linux/smp.h>
   5 #include <linux/sched.h>
   6 #include <linux/hugetlb.h>
   7 #include <asm/sbi.h>
   8 #include <asm/mmu_context.h>
   9
  10 /*
  11  * Flush entire TLB if number of entries to be flushed is greater
  12  * than the threshold below.
  13  */
  14 unsigned long tlb_flush_all_threshold __read_mostly = 64;
  15
  16 static void local_flush_tlb_range_threshold_asid(unsigned long start,
  17                                                  unsigned long size,
  18                                                  unsigned long stride,
  19                                                  unsigned long asid)
  20 {
  21         unsigned long nr_ptes_in_range = DIV_ROUND_UP(size, stride);
  22         int i;
  23
  24         if (nr_ptes_in_range > tlb_flush_all_threshold) {
  25                 local_flush_tlb_all_asid(asid);
  26                 return;
  27         }
  28
  29         for (i = 0; i < nr_ptes_in_range; ++i) {
  30                 local_flush_tlb_page_asid(start, asid);
  31                 start += stride;
  32         }
  33 }
  34
  35 static inline void local_flush_tlb_range_asid(unsigned long start,
  36                 unsigned long size, unsigned long stride, unsigned long asid)
  37 {
  38         if (size <= stride)
  39                 local_flush_tlb_page_asid(start, asid);
  40         else if (size == FLUSH_TLB_MAX_SIZE)
  41                 local_flush_tlb_all_asid(asid);
  42         else
  43                 local_flush_tlb_range_threshold_asid(start, size, stride, asid);
  44 }
  45
  46 /* Flush a range of kernel pages without broadcasting */
  47 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
  48 {
  49         local_flush_tlb_range_asid(start, end - start, PAGE_SIZE, FLUSH_TLB_NO_ASID);
  50 }
  51
  52 static void __ipi_flush_tlb_all(void *info)
  53 {
  54         local_flush_tlb_all();
  55 }
  56
  57 void flush_tlb_all(void)
  58 {
  59         if (num_online_cpus() < 2)
  60                 local_flush_tlb_all();
  61         else if (riscv_use_sbi_for_rfence())
  62                 sbi_remote_sfence_vma_asid(NULL, 0, FLUSH_TLB_MAX_SIZE, FLUSH_TLB_NO_ASID);
  63         else
  64                 on_each_cpu(__ipi_flush_tlb_all, NULL, 1);
  65 }
  66
  67 struct flush_tlb_range_data {
  68         unsigned long asid;
  69         unsigned long start;
  70         unsigned long size;
  71         unsigned long stride;
  72 };
  73
  74 static void __ipi_flush_tlb_range_asid(void *info)
  75 {
  76         struct flush_tlb_range_data *d = info;
  77
  78         local_flush_tlb_range_asid(d->start, d->size, d->stride, d->asid);
  79 }
  80
  81 static void __flush_tlb_range(const struct cpumask *cmask, unsigned long asid,
  82                               unsigned long start, unsigned long size,
  83                               unsigned long stride)
  84 {
  85         unsigned int cpu;
  86
  87         if (cpumask_empty(cmask))
  88                 return;
  89
  90         cpu = get_cpu();
  91
  92         /* Check if the TLB flush needs to be sent to other CPUs. */
  93         if (cpumask_any_but(cmask, cpu) >= nr_cpu_ids) {
  94                 local_flush_tlb_range_asid(start, size, stride, asid);
  95         } else if (riscv_use_sbi_for_rfence()) {
  96                 sbi_remote_sfence_vma_asid(cmask, start, size, asid);
  97         } else {
  98                 struct flush_tlb_range_data ftd;
  99
 100                 ftd.asid = asid;
 101                 ftd.start = start;
 102                 ftd.size = size;
 103                 ftd.stride = stride;
 104                 on_each_cpu_mask(cmask, __ipi_flush_tlb_range_asid, &ftd, 1);
 105         }
 106
 107         put_cpu();
 108 }
 109
 110 static inline unsigned long get_mm_asid(struct mm_struct *mm)
 111 {
 112         return cntx2asid(atomic_long_read(&mm->context.id));
 113 }
 114
 115 void flush_tlb_mm(struct mm_struct *mm)
 116 {
 117         __flush_tlb_range(mm_cpumask(mm), get_mm_asid(mm),
 118                           0, FLUSH_TLB_MAX_SIZE, PAGE_SIZE);
 119 }
 120
 121 void flush_tlb_mm_range(struct mm_struct *mm,
 122                         unsigned long start, unsigned long end,
 123                         unsigned int page_size)
 124 {
 125         __flush_tlb_range(mm_cpumask(mm), get_mm_asid(mm),
 126                           start, end - start, page_size);
 127 }
 128
 129 void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
 130 {
 131         __flush_tlb_range(mm_cpumask(vma->vm_mm), get_mm_asid(vma->vm_mm),
 132                           addr, PAGE_SIZE, PAGE_SIZE);
 133 }
 134
 135 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 136                      unsigned long end)
 137 {
 138         unsigned long stride_size;
 139
 140         if (!is_vm_hugetlb_page(vma)) {
 141                 stride_size = PAGE_SIZE;
 142         } else {
 143                 stride_size = huge_page_size(hstate_vma(vma));
 144
 145                 /*
 146                  * As stated in the privileged specification, every PTE in a
 147                  * NAPOT region must be invalidated, so reset the stride in that
 148                  * case.
 149                  */
 150                 if (has_svnapot()) {
 151                         if (stride_size >= PGDIR_SIZE)
 152                                 stride_size = PGDIR_SIZE;
 153                         else if (stride_size >= P4D_SIZE)
 154                                 stride_size = P4D_SIZE;
 155                         else if (stride_size >= PUD_SIZE)
 156                                 stride_size = PUD_SIZE;
 157                         else if (stride_size >= PMD_SIZE)
 158                                 stride_size = PMD_SIZE;
 159                         else
 160                                 stride_size = PAGE_SIZE;
 161                 }
 162         }
 163
 164         __flush_tlb_range(mm_cpumask(vma->vm_mm), get_mm_asid(vma->vm_mm),
 165                           start, end - start, stride_size);
 166 }
 167
 168 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 169 {
 170         __flush_tlb_range(cpu_online_mask, FLUSH_TLB_NO_ASID,
 171                           start, end - start, PAGE_SIZE);
 172 }
 173
 174 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 175 void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,
 176                         unsigned long end)
 177 {
 178         __flush_tlb_range(mm_cpumask(vma->vm_mm), get_mm_asid(vma->vm_mm),
 179                           start, end - start, PMD_SIZE);
 180 }
 181 #endif
 182
 183 bool arch_tlbbatch_should_defer(struct mm_struct *mm)
 184 {
 185         return true;
 186 }
 187
 188 void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch,
 189                                struct mm_struct *mm,
 190                                unsigned long uaddr)
 191 {
 192         cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm));
 193 }
 194
 195 void arch_flush_tlb_batched_pending(struct mm_struct *mm)
 196 {
 197         flush_tlb_mm(mm);
 198 }
 199
 200 void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
 201 {
 202         __flush_tlb_range(&batch->cpumask, FLUSH_TLB_NO_ASID, 0,
 203                           FLUSH_TLB_MAX_SIZE, PAGE_SIZE);
 204         cpumask_clear(&batch->cpumask);
 205 }