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 */
copro_handle_mm_fault(struct mm_struct * mm,unsigned long ea,unsigned long dsisr,vm_fault_t * flt)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 mmap_read_lock(mm);
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, NULL);
68
69 /* The fault is fully completed (including releasing mmap lock) */
70 if (*flt & VM_FAULT_COMPLETED)
71 return 0;
72
73 if (unlikely(*flt & VM_FAULT_ERROR)) {
74 if (*flt & VM_FAULT_OOM) {
75 ret = -ENOMEM;
76 goto out_unlock;
77 } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
78 ret = -EFAULT;
79 goto out_unlock;
80 }
81 BUG();
82 }
83
84 out_unlock:
85 mmap_read_unlock(mm);
86 return ret;
87 }
88 EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
89
90 #ifdef CONFIG_PPC_64S_HASH_MMU
copro_calculate_slb(struct mm_struct * mm,u64 ea,struct copro_slb * slb)91 int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
92 {
93 u64 vsid, vsidkey;
94 int psize, ssize;
95
96 switch (get_region_id(ea)) {
97 case USER_REGION_ID:
98 pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
99 if (mm == NULL)
100 return 1;
101 psize = get_slice_psize(mm, ea);
102 ssize = user_segment_size(ea);
103 vsid = get_user_vsid(&mm->context, ea, ssize);
104 vsidkey = SLB_VSID_USER;
105 break;
106 case VMALLOC_REGION_ID:
107 pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
108 psize = mmu_vmalloc_psize;
109 ssize = mmu_kernel_ssize;
110 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
111 vsidkey = SLB_VSID_KERNEL;
112 break;
113 case IO_REGION_ID:
114 pr_devel("%s: 0x%llx -- IO_REGION_ID\n", __func__, ea);
115 psize = mmu_io_psize;
116 ssize = mmu_kernel_ssize;
117 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
118 vsidkey = SLB_VSID_KERNEL;
119 break;
120 case LINEAR_MAP_REGION_ID:
121 pr_devel("%s: 0x%llx -- LINEAR_MAP_REGION_ID\n", __func__, ea);
122 psize = mmu_linear_psize;
123 ssize = mmu_kernel_ssize;
124 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
125 vsidkey = SLB_VSID_KERNEL;
126 break;
127 default:
128 pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
129 return 1;
130 }
131 /* Bad address */
132 if (!vsid)
133 return 1;
134
135 vsid = (vsid << slb_vsid_shift(ssize)) | vsidkey;
136
137 vsid |= mmu_psize_defs[psize].sllp |
138 ((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
139
140 slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V;
141 slb->vsid = vsid;
142
143 return 0;
144 }
145 EXPORT_SYMBOL_GPL(copro_calculate_slb);
146
copro_flush_all_slbs(struct mm_struct * mm)147 void copro_flush_all_slbs(struct mm_struct *mm)
148 {
149 #ifdef CONFIG_SPU_BASE
150 spu_flush_all_slbs(mm);
151 #endif
152 cxl_slbia(mm);
153 }
154 EXPORT_SYMBOL_GPL(copro_flush_all_slbs);
155 #endif
156