1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License, version 2, as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
9 * GNU General Public License for more details.
10 *
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
14 *
15 * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
16 * Copyright 2011 David Gibson, IBM Corporation <dwg@au1.ibm.com>
17 */
18
19#include <linux/types.h>
20#include <linux/string.h>
21#include <linux/kvm.h>
22#include <linux/kvm_host.h>
23#include <linux/highmem.h>
24#include <linux/gfp.h>
25#include <linux/slab.h>
26#include <linux/hugetlb.h>
27#include <linux/list.h>
28#include <linux/anon_inodes.h>
29
30#include <asm/tlbflush.h>
31#include <asm/kvm_ppc.h>
32#include <asm/kvm_book3s.h>
33#include <asm/mmu-hash64.h>
34#include <asm/hvcall.h>
35#include <asm/synch.h>
36#include <asm/ppc-opcode.h>
37#include <asm/kvm_host.h>
38#include <asm/udbg.h>
39
40#define TCES_PER_PAGE	(PAGE_SIZE / sizeof(u64))
41
42static long kvmppc_stt_npages(unsigned long window_size)
43{
44	return ALIGN((window_size >> SPAPR_TCE_SHIFT)
45		     * sizeof(u64), PAGE_SIZE) / PAGE_SIZE;
46}
47
48static void release_spapr_tce_table(struct kvmppc_spapr_tce_table *stt)
49{
50	struct kvm *kvm = stt->kvm;
51	int i;
52
53	mutex_lock(&kvm->lock);
54	list_del(&stt->list);
55	for (i = 0; i < kvmppc_stt_npages(stt->window_size); i++)
56		__free_page(stt->pages[i]);
57	kfree(stt);
58	mutex_unlock(&kvm->lock);
59
60	kvm_put_kvm(kvm);
61}
62
63static int kvm_spapr_tce_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
64{
65	struct kvmppc_spapr_tce_table *stt = vma->vm_file->private_data;
66	struct page *page;
67
68	if (vmf->pgoff >= kvmppc_stt_npages(stt->window_size))
69		return VM_FAULT_SIGBUS;
70
71	page = stt->pages[vmf->pgoff];
72	get_page(page);
73	vmf->page = page;
74	return 0;
75}
76
77static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
78	.fault = kvm_spapr_tce_fault,
79};
80
81static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma)
82{
83	vma->vm_ops = &kvm_spapr_tce_vm_ops;
84	return 0;
85}
86
87static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
88{
89	struct kvmppc_spapr_tce_table *stt = filp->private_data;
90
91	release_spapr_tce_table(stt);
92	return 0;
93}
94
95static const struct file_operations kvm_spapr_tce_fops = {
96	.mmap           = kvm_spapr_tce_mmap,
97	.release	= kvm_spapr_tce_release,
98};
99
100long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
101				   struct kvm_create_spapr_tce *args)
102{
103	struct kvmppc_spapr_tce_table *stt = NULL;
104	long npages;
105	int ret = -ENOMEM;
106	int i;
107
108	/* Check this LIOBN hasn't been previously allocated */
109	list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
110		if (stt->liobn == args->liobn)
111			return -EBUSY;
112	}
113
114	npages = kvmppc_stt_npages(args->window_size);
115
116	stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
117		      GFP_KERNEL);
118	if (!stt)
119		goto fail;
120
121	stt->liobn = args->liobn;
122	stt->window_size = args->window_size;
123	stt->kvm = kvm;
124
125	for (i = 0; i < npages; i++) {
126		stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
127		if (!stt->pages[i])
128			goto fail;
129	}
130
131	kvm_get_kvm(kvm);
132
133	mutex_lock(&kvm->lock);
134	list_add(&stt->list, &kvm->arch.spapr_tce_tables);
135
136	mutex_unlock(&kvm->lock);
137
138	return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
139				stt, O_RDWR | O_CLOEXEC);
140
141fail:
142	if (stt) {
143		for (i = 0; i < npages; i++)
144			if (stt->pages[i])
145				__free_page(stt->pages[i]);
146
147		kfree(stt);
148	}
149	return ret;
150}
151