1/*
2 * CoProcessor (SPU/AFU) mm fault handler
3 *
4 * (C) Copyright IBM Deutschland Entwicklung GmbH 2007
5 *
6 * Author: Arnd Bergmann <arndb@de.ibm.com>
7 * Author: Jeremy Kerr <jk@ozlabs.org>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2, or (at your option)
12 * any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23#include <linux/sched.h>
24#include <linux/mm.h>
25#include <linux/export.h>
26#include <asm/reg.h>
27#include <asm/copro.h>
28#include <asm/spu.h>
29#include <misc/cxl.h>
30
31/*
32 * This ought to be kept in sync with the powerpc specific do_page_fault
33 * function. Currently, there are a few corner cases that we haven't had
34 * to handle fortunately.
35 */
36int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
37		unsigned long dsisr, unsigned *flt)
38{
39	struct vm_area_struct *vma;
40	unsigned long is_write;
41	int ret;
42
43	if (mm == NULL)
44		return -EFAULT;
45
46	if (mm->pgd == NULL)
47		return -EFAULT;
48
49	down_read(&mm->mmap_sem);
50	ret = -EFAULT;
51	vma = find_vma(mm, ea);
52	if (!vma)
53		goto out_unlock;
54
55	if (ea < vma->vm_start) {
56		if (!(vma->vm_flags & VM_GROWSDOWN))
57			goto out_unlock;
58		if (expand_stack(vma, ea))
59			goto out_unlock;
60	}
61
62	is_write = dsisr & DSISR_ISSTORE;
63	if (is_write) {
64		if (!(vma->vm_flags & VM_WRITE))
65			goto out_unlock;
66	} else {
67		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
68			goto out_unlock;
69		/*
70		 * protfault should only happen due to us
71		 * mapping a region readonly temporarily. PROT_NONE
72		 * is also covered by the VMA check above.
73		 */
74		WARN_ON_ONCE(dsisr & DSISR_PROTFAULT);
75	}
76
77	ret = 0;
78	*flt = handle_mm_fault(mm, vma, ea, is_write ? FAULT_FLAG_WRITE : 0);
79	if (unlikely(*flt & VM_FAULT_ERROR)) {
80		if (*flt & VM_FAULT_OOM) {
81			ret = -ENOMEM;
82			goto out_unlock;
83		} else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) {
84			ret = -EFAULT;
85			goto out_unlock;
86		}
87		BUG();
88	}
89
90	if (*flt & VM_FAULT_MAJOR)
91		current->maj_flt++;
92	else
93		current->min_flt++;
94
95out_unlock:
96	up_read(&mm->mmap_sem);
97	return ret;
98}
99EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
100
101int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
102{
103	u64 vsid;
104	int psize, ssize;
105
106	switch (REGION_ID(ea)) {
107	case USER_REGION_ID:
108		pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
109		psize = get_slice_psize(mm, ea);
110		ssize = user_segment_size(ea);
111		vsid = get_vsid(mm->context.id, ea, ssize);
112		break;
113	case VMALLOC_REGION_ID:
114		pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
115		if (ea < VMALLOC_END)
116			psize = mmu_vmalloc_psize;
117		else
118			psize = mmu_io_psize;
119		ssize = mmu_kernel_ssize;
120		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
121		break;
122	case KERNEL_REGION_ID:
123		pr_devel("%s: 0x%llx -- KERNEL_REGION_ID\n", __func__, ea);
124		psize = mmu_linear_psize;
125		ssize = mmu_kernel_ssize;
126		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
127		break;
128	default:
129		pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
130		return 1;
131	}
132
133	vsid = (vsid << slb_vsid_shift(ssize)) | SLB_VSID_USER;
134
135	vsid |= mmu_psize_defs[psize].sllp |
136		((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
137
138	slb->esid = (ea & (ssize == MMU_SEGSIZE_1T ? ESID_MASK_1T : ESID_MASK)) | SLB_ESID_V;
139	slb->vsid = vsid;
140
141	return 0;
142}
143EXPORT_SYMBOL_GPL(copro_calculate_slb);
144
145void copro_flush_all_slbs(struct mm_struct *mm)
146{
147#ifdef CONFIG_SPU_BASE
148	spu_flush_all_slbs(mm);
149#endif
150	cxl_slbia(mm);
151}
152EXPORT_SYMBOL_GPL(copro_flush_all_slbs);
153