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 */
copro_handle_mm_fault(struct mm_struct * mm,unsigned long ea,unsigned long dsisr,vm_fault_t * flt)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
copro_calculate_slb(struct mm_struct * mm,u64 ea,struct copro_slb * slb)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
137