path: root/arch/powerpc/kernel/iommu.c

/*
 * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
 * 
 * Rewrite, cleanup, new allocation schemes, virtual merging: 
 * Copyright (C) 2004 Olof Johansson, IBM Corporation
 *               and  Ben. Herrenschmidt, IBM Corporation
 *
 * Dynamic DMA mapping support, bus-independent parts.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */


#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/dma-mapping.h>
#include <linux/bitmap.h>
#include <linux/iommu-helper.h>
#include <linux/crash_dump.h>
#include <linux/hash.h>
#include <linux/fault-inject.h>
#include <linux/pci.h>
#include <linux/iommu.h>
#include <linux/sched.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/iommu.h>
#include <asm/pci-bridge.h>
#include <asm/machdep.h>
#include <asm/kdump.h>
#include <asm/fadump.h>
#include <asm/vio.h>
#include <asm/tce.h>

#define DBG(...)

static int novmerge;

static void __iommu_free(struct iommu_table *, dma_addr_t, unsigned int);

static int __init setup_iommu(char *str)
{
	if (!strcmp(str, "novmerge"))
		novmerge = 1;
	else if (!strcmp(str, "vmerge"))
		novmerge = 0;
	return 1;
}

__setup("iommu=", setup_iommu);

static DEFINE_PER_CPU(unsigned int, iommu_pool_hash);

/*
 * We precalculate the hash to avoid doing it on every allocation.
 *
 * The hash is important to spread CPUs across all the pools. For example,
 * on a POWER7 with 4 way SMT we want interrupts on the primary threads and
 * with 4 pools all primary threads would map to the same pool.
 */
static int __init setup_iommu_pool_hash(void)
{
	unsigned int i;

	for_each_possible_cpu(i)
		per_cpu(iommu_pool_hash, i) = hash_32(i, IOMMU_POOL_HASHBITS);

	return 0;
}
subsys_initcall(setup_iommu_pool_hash);

#ifdef CONFIG_FAIL_IOMMU

static DECLARE_FAULT_ATTR(fail_iommu);

static int __init setup_fail_iommu(char *str)
{
	return setup_fault_attr(&fail_iommu, str);
}
__setup("fail_iommu=", setup_fail_iommu);

static bool should_fail_iommu(struct device *dev)
{
	return dev->archdata.fail_iommu && should_fail(&fail_iommu, 1);
}

static int __init fail_iommu_debugfs(void)
{
	struct dentry *dir = fault_create_debugfs_attr("fail_iommu",
						       NULL, &fail_iommu);

	return PTR_ERR_OR_ZERO(dir);
}
late_initcall(fail_iommu_debugfs);

static ssize_t fail_iommu_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", dev->archdata.fail_iommu);
}

static ssize_t fail_iommu_store(struct device *dev,
				struct device_attribute *attr, const char *buf,
				size_t count)
{
	int i;

	if (count > 0 && sscanf(buf, "%d", &i) > 0)
		dev->archdata.fail_iommu = (i == 0) ? 0 : 1;

	return count;
}

static DEVICE_ATTR(fail_iommu, S_IRUGO|S_IWUSR, fail_iommu_show,
		   fail_iommu_store);

static int fail_iommu_bus_notify(struct notifier