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 */
23int 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
76out_unlock:
77	mmap_read_unlock(mm);
78	return ret;
79}
80EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
81
82#ifdef CONFIG_PPC_64S_HASH_MMU
83int 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}
137EXPORT_SYMBOL_GPL(copro_calculate_slb);
138
139void 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}
146EXPORT_SYMBOL_GPL(copro_flush_all_slbs);
147#endif
148