arch/powerpc/mm/copro_fault.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * CoProcessor (SPU/AFU) mm fault handler
   4  *
   5  * (C) Copyright IBM Deutschland Entwicklung GmbH 2007
   6  *
   7  * Author: Arnd Bergmann <[email protected]>
   8  * Author: Jeremy Kerr <[email protected]>
   9  */
  10 #include <linux/sched.h>
  11 #include <linux/mm.h>
  12 #include <linux/export.h>
  13 #include <asm/reg.h>
  14 #include <asm/copro.h>
  15 #include <asm/spu.h>
  16 #include <misc/cxl-base.h>
  17
  18 /*
  19  * This ought to be kept in sync with the powerpc specific do_page_fault
  20  * function. Currently, there are a few corner cases that we haven't had
  21  * to handle fortunately.
  22  */
  23 int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
  24                 unsigned long dsisr, vm_fault_t *flt)
  25 {
  26         struct vm_area_struct *vma;
  27         unsigned long is_write;
  28         int ret;
  29
  30         if (mm == NULL)
  31                 return -EFAULT;
  32
  33         if (mm->pgd == NULL)
  34                 return -EFAULT;
  35
  36         mmap_read_lock(mm);
  37         ret = -EFAULT;
  38         vma = find_vma(mm, ea);
  39         if (!vma)
  40                 goto out_unlock;
  41
  42         if (ea < vma->vm_start) {
  43                 if (!(vma->vm_flags & VM_GROWSDOWN))
  44                         goto out_unlock;
  45                 if (expand_stack(vma, ea))
  46                         goto out_unlock;
  47         }
  48
  49         is_write = dsisr & DSISR_ISSTORE;
  50         if (is_write) {
  51                 if (!(vma->vm_flags & VM_WRITE))
  52                         goto out_unlock;
  53         } else {
  54                 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
  55                         goto out_unlock;
  56                 /*
  57                  * PROT_NONE is covered by the VMA check above.
  58                  * and hash should get a NOHPTE fault instead of
  59                  * a PROTFAULT in case fixup is needed for things
  60                  * like autonuma.
  61                  */
  62                 if (!radix_enabled())
  63                         WARN_ON_ONCE(dsisr & DSISR_PROTFAULT);
  64         }
  65
  66         ret = 0;
  67         *flt = handle_mm_fault(vma, ea, is_write ? FAULT_FLAG_WRITE : 0, NULL);
  68
  69         /* The fault is fully completed (including releasing mmap lock) */
  70         if (*flt & VM_FAULT_COMPLETED)
  71                 return 0;
  72
  73         if (unlikely(*flt & VM_FAULT_ERROR)) {
  74                 if (*flt & VM_FAULT_OOM) {
  75                         ret = -ENOMEM;
  76                         goto out_unlock;
  77                 } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
  78                         ret = -EFAULT;
  79                         goto out_unlock;
  80                 }
  81                 BUG();
  82         }
  83
  84 out_unlock:
  85         mmap_read_unlock(mm);
  86         return ret;
  87 }
  88 EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
  89
  90 #ifdef CONFIG_PPC_64S_HASH_MMU
  91 int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
  92 {
  93         u64 vsid, vsidkey;
  94         int psize, ssize;
  95
  96         switch (get_region_id(ea)) {
  97         case USER_REGION_ID:
  98                 pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
  99                 if (mm == NULL)
 100                         return 1;
 101                 psize = get_slice_psize(mm, ea);
 102                 ssize = user_segment_size(ea);
 103                 vsid = get_user_vsid(&mm->context, ea, ssize);
 104                 vsidkey = SLB_VSID_USER;
 105                 break;
 106         case VMALLOC_REGION_ID:
 107                 pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
 108                 psize = mmu_vmalloc_psize;
 109                 ssize = mmu_kernel_ssize;
 110                 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 111                 vsidkey = SLB_VSID_KERNEL;
 112                 break;
 113         case IO_REGION_ID:
 114                 pr_devel("%s: 0x%llx -- IO_REGION_ID\n", __func__, ea);
 115                 psize = mmu_io_psize;
 116                 ssize = mmu_kernel_ssize;
 117                 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 118                 vsidkey = SLB_VSID_KERNEL;
 119                 break;
 120         case LINEAR_MAP_REGION_ID:
 121                 pr_devel("%s: 0x%llx -- LINEAR_MAP_REGION_ID\n", __func__, ea);
 122                 psize = mmu_linear_psize;
 123                 ssize = mmu_kernel_ssize;
 124                 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 125                 vsidkey = SLB_VSID_KERNEL;
 126                 break;
 127         default:
 128                 pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
 129                 return 1;
 130         }
 131         /* Bad address */
 132         if (!vsid)
 133                 return 1;
 134
 135         vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey;
 136
 137         vsid |= mmu_psize_defs[psize].sllp |
 138                 ((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
 139
 140         slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V;
 141         slb->vsid = vsid;
 142
 143         return 0;
 144 }
 145 EXPORT_SYMBOL_GPL(copro_calculate_slb);
 146
 147 void copro_flush_all_slbs(struct mm_struct *mm)
 148 {
 149 #ifdef CONFIG_SPU_BASE
 150         spu_flush_all_slbs(mm);
 151 #endif
 152         cxl_slbia(mm);
 153 }
 154 EXPORT_SYMBOL_GPL(copro_flush_all_slbs);
 155 #endif