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
148
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