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