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 <arndb@de.ibm.com>
   8  * Author: Jeremy Kerr <jk@ozlabs.org>
   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         vma = lock_mm_and_find_vma(mm, ea, NULL);
  37         if (!vma)
  38                 return -EFAULT;
  39
  40         ret = -EFAULT;
  41         is_write = dsisr & DSISR_ISSTORE;
  42         if (is_write) {
  43                 if (!(vma->vm_flags & VM_WRITE))
  44                         goto out_unlock;
  45         } else {
  46                 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
  47                         goto out_unlock;
  48                 /*
  49                  * PROT_NONE is covered by the VMA check above.
  50                  * and hash should get a NOHPTE fault instead of
  51                  * a PROTFAULT in case fixup is needed for things
  52                  * like autonuma.
  53                  */
  54                 if (!radix_enabled())
  55                         WARN_ON_ONCE(dsisr & DSISR_PROTFAULT);
  56         }
  57
  58         ret = 0;
  59         *flt = handle_mm_fault(vma, ea, is_write ? FAULT_FLAG_WRITE : 0, NULL);
  60
  61         /* The fault is fully completed (including releasing mmap lock) */
  62         if (*flt & VM_FAULT_COMPLETED)
  63                 return 0;
  64
  65         if (unlikely(*flt & VM_FAULT_ERROR)) {
  66                 if (*flt & VM_FAULT_OOM) {
  67                         ret = -ENOMEM;
  68                         goto out_unlock;
  69                 } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
  70                         ret = -EFAULT;
  71                         goto out_unlock;
  72                 }
  73                 BUG();
  74         }
  75
  76 out_unlock:
  77         mmap_read_unlock(mm);
  78         return ret;
  79 }
  80 EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
  81
  82 #ifdef CONFIG_PPC_64S_HASH_MMU
  83 int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
  84 {
  85         u64 vsid, vsidkey;
  86         int psize, ssize;
  87
  88         switch (get_region_id(ea)) {
  89         case USER_REGION_ID:
  90                 pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
  91                 if (mm == NULL)
  92                         return 1;
  93                 psize = get_slice_psize(mm, ea);
  94                 ssize = user_segment_size(ea);
  95                 vsid = get_user_vsid(&mm->context, ea, ssize);
  96                 vsidkey = SLB_VSID_USER;
  97                 break;
  98         case VMALLOC_REGION_ID:
  99                 pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
 100                 psize = mmu_vmalloc_psize;
 101                 ssize = mmu_kernel_ssize;
 102                 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 103                 vsidkey = SLB_VSID_KERNEL;
 104                 break;
 105         case IO_REGION_ID:
 106                 pr_devel("%s: 0x%llx -- IO_REGION_ID\n", __func__, ea);
 107                 psize = mmu_io_psize;
 108                 ssize = mmu_kernel_ssize;
 109                 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 110                 vsidkey = SLB_VSID_KERNEL;
 111                 break;
 112         case LINEAR_MAP_REGION_ID:
 113                 pr_devel("%s: 0x%llx -- LINEAR_MAP_REGION_ID\n", __func__, ea);
 114                 psize = mmu_linear_psize;
 115                 ssize = mmu_kernel_ssize;
 116                 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 117                 vsidkey = SLB_VSID_KERNEL;
 118                 break;
 119         default:
 120                 pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
 121                 return 1;
 122         }
 123         /* Bad address */
 124         if (!vsid)
 125                 return 1;
 126
 127         vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey;
 128
 129         vsid |= mmu_psize_defs[psize].sllp |
 130                 ((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
 131
 132         slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V;
 133         slb->vsid = vsid;
 134
 135         return 0;
 136 }
 137 EXPORT_SYMBOL_GPL(copro_calculate_slb);
 138
 139 void copro_flush_all_slbs(struct mm_struct *mm)
 140 {
 141 #ifdef CONFIG_SPU_BASE
 142         spu_flush_all_slbs(mm);
 143 #endif
 144         cxl_slbia(mm);
 145 }
 146 EXPORT_SYMBOL_GPL(copro_flush_all_slbs);
 147 #endif