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