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         down_read(&mm->mmap_sem);
  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);
  68         if (unlikely(*flt & VM_FAULT_ERROR)) {
  69                 if (*flt & VM_FAULT_OOM) {
  70                         ret = -ENOMEM;
  71                         goto out_unlock;
  72                 } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
  73                         ret = -EFAULT;
  74                         goto out_unlock;
  75                 }
  76                 BUG();
  77         }
  78
  79         if (*flt & VM_FAULT_MAJOR)
  80                 current->maj_flt++;
  81         else
  82                 current->min_flt++;
  83
  84 out_unlock:
  85         up_read(&mm->mmap_sem);
  86         return ret;
  87 }
  88 EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
  89
  90 int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
  91 {
  92         u64 vsid, vsidkey;
  93         int psize, ssize;
  94
  95         switch (get_region_id(ea)) {
  96         case USER_REGION_ID:
  97                 pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
  98                 if (mm == NULL)
  99                         return 1;
 100                 psize = get_slice_psize(mm, ea);
 101                 ssize = user_segment_size(ea);
 102                 vsid = get_user_vsid(&mm->context, ea, ssize);
 103                 vsidkey = SLB_VSID_USER;
 104                 break;
 105         case VMALLOC_REGION_ID:
 106                 pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
 107                 psize = mmu_vmalloc_psize;
 108                 ssize = mmu_kernel_ssize;
 109                 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 110                 vsidkey = SLB_VSID_KERNEL;
 111                 break;
 112         case IO_REGION_ID:
 113                 pr_devel("%s: 0x%llx -- IO_REGION_ID\n", __func__, ea);
 114                 psize = mmu_io_psize;
 115                 ssize = mmu_kernel_ssize;
 116                 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 117                 vsidkey = SLB_VSID_KERNEL;
 118                 break;
 119         case LINEAR_MAP_REGION_ID:
 120                 pr_devel("%s: 0x%llx -- LINEAR_MAP_REGION_ID\n", __func__, ea);
 121                 psize = mmu_linear_psize;
 122                 ssize = mmu_kernel_ssize;
 123                 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 124                 vsidkey = SLB_VSID_KERNEL;
 125                 break;
 126         default:
 127                 pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
 128                 return 1;
 129         }
 130         /* Bad address */
 131         if (!vsid)
 132                 return 1;
 133
 134         vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey;
 135
 136         vsid |= mmu_psize_defs[psize].sllp |
 137                 ((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
 138
 139         slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V;
 140         slb->vsid = vsid;
 141
 142         return 0;
 143 }
 144 EXPORT_SYMBOL_GPL(copro_calculate_slb);
 145
 146 void copro_flush_all_slbs(struct mm_struct *mm)
 147 {
 148 #ifdef CONFIG_SPU_BASE
 149         spu_flush_all_slbs(mm);
 150 #endif
 151         cxl_slbia(mm);
 152 }
 153 EXPORT_SYMBOL_GPL(copro_flush_all_slbs);