| 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 | |
| 16 | /* |
| 17 | * This ought to be kept in sync with the powerpc specific do_page_fault |
| 18 | * function. Currently, there are a few corner cases that we haven't had |
| 19 | * to handle fortunately. |
| 20 | */ |
| 21 | int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea, |
| 22 | unsigned long dsisr, vm_fault_t *flt) |
| 23 | { |
| 24 | struct vm_area_struct *vma; |
| 25 | unsigned long is_write; |
| 26 | int ret; |
| 27 | |
| 28 | if (mm == NULL) |
| 29 | return -EFAULT; |
| 30 | |
| 31 | if (mm->pgd == NULL) |
| 32 | return -EFAULT; |
| 33 | |
| 34 | vma = lock_mm_and_find_vma(mm, ea, NULL); |
| 35 | if (!vma) |
| 36 | return -EFAULT; |
| 37 | |
| 38 | ret = -EFAULT; |
| 39 | is_write = dsisr & DSISR_ISSTORE; |
| 40 | if (is_write) { |
| 41 | if (!(vma->vm_flags & VM_WRITE)) |
| 42 | goto out_unlock; |
| 43 | } else { |
| 44 | if (!(vma->vm_flags & (VM_READ | VM_EXEC))) |
| 45 | goto out_unlock; |
| 46 | /* |
| 47 | * PROT_NONE is covered by the VMA check above. |
| 48 | * and hash should get a NOHPTE fault instead of |
| 49 | * a PROTFAULT in case fixup is needed for things |
| 50 | * like autonuma. |
| 51 | */ |
| 52 | if (!radix_enabled()) |
| 53 | WARN_ON_ONCE(dsisr & DSISR_PROTFAULT); |
| 54 | } |
| 55 | |
| 56 | ret = 0; |
| 57 | *flt = handle_mm_fault(vma, ea, is_write ? FAULT_FLAG_WRITE : 0, NULL); |
| 58 | |
| 59 | /* The fault is fully completed (including releasing mmap lock) */ |
| 60 | if (*flt & VM_FAULT_COMPLETED) |
| 61 | return 0; |
| 62 | |
| 63 | if (unlikely(*flt & VM_FAULT_ERROR)) { |
| 64 | if (*flt & VM_FAULT_OOM) { |
| 65 | ret = -ENOMEM; |
| 66 | goto out_unlock; |
| 67 | } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) { |
| 68 | ret = -EFAULT; |
| 69 | goto out_unlock; |
| 70 | } |
| 71 | BUG(); |
| 72 | } |
| 73 | |
| 74 | out_unlock: |
| 75 | mmap_read_unlock(mm); |
| 76 | return ret; |
| 77 | } |
| 78 | EXPORT_SYMBOL_GPL(copro_handle_mm_fault); |
| 79 | |
| 80 | #ifdef CONFIG_PPC_64S_HASH_MMU |
| 81 | int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb) |
| 82 | { |
| 83 | u64 vsid, vsidkey; |
| 84 | int psize, ssize; |
| 85 | |
| 86 | switch (get_region_id(ea)) { |
| 87 | case USER_REGION_ID: |
| 88 | pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea); |
| 89 | if (mm == NULL) |
| 90 | return 1; |
| 91 | psize = get_slice_psize(mm, ea); |
| 92 | ssize = user_segment_size(ea); |
| 93 | vsid = get_user_vsid(&mm->context, ea, ssize); |
| 94 | vsidkey = SLB_VSID_USER; |
| 95 | break; |
| 96 | case VMALLOC_REGION_ID: |
| 97 | pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea); |
| 98 | psize = mmu_vmalloc_psize; |
| 99 | ssize = mmu_kernel_ssize; |
| 100 | vsid = get_kernel_vsid(ea, mmu_kernel_ssize); |
| 101 | vsidkey = SLB_VSID_KERNEL; |
| 102 | break; |
| 103 | case IO_REGION_ID: |
| 104 | pr_devel("%s: 0x%llx -- IO_REGION_ID\n", __func__, ea); |
| 105 | psize = mmu_io_psize; |
| 106 | ssize = mmu_kernel_ssize; |
| 107 | vsid = get_kernel_vsid(ea, mmu_kernel_ssize); |
| 108 | vsidkey = SLB_VSID_KERNEL; |
| 109 | break; |
| 110 | case LINEAR_MAP_REGION_ID: |
| 111 | pr_devel("%s: 0x%llx -- LINEAR_MAP_REGION_ID\n", __func__, ea); |
| 112 | psize = mmu_linear_psize; |
| 113 | ssize = mmu_kernel_ssize; |
| 114 | vsid = get_kernel_vsid(ea, mmu_kernel_ssize); |
| 115 | vsidkey = SLB_VSID_KERNEL; |
| 116 | break; |
| 117 | default: |
| 118 | pr_debug("%s: invalid region access at %016llx\n", __func__, ea); |
| 119 | return 1; |
| 120 | } |
| 121 | /* Bad address */ |
| 122 | if (!vsid) |
| 123 | return 1; |
| 124 | |
| 125 | vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey; |
| 126 | |
| 127 | vsid |= mmu_psize_defs[psize].sllp | |
| 128 | ((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0); |
| 129 | |
| 130 | slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V; |
| 131 | slb->vsid = vsid; |
| 132 | |
| 133 | return 0; |
| 134 | } |
| 135 | EXPORT_SYMBOL_GPL(copro_calculate_slb); |
| 136 | #endif |