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 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);
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}