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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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.
 */


#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 <linux/debugfs.h>
#include <asm/io.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>
#include <asm/mmu_context.h>

#define DBG(...)

#ifdef CONFIG_IOMMU_DEBUGFS
static int iommu_debugfs_weight_get(void *data, u64 *val)
{
	struct iommu_table *tbl = data;
	*val = bitmap_weight(tbl->it_map, tbl->it_size);
	return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(iommu_debugfs_fops_weight, iommu_debugfs_weight_get, NULL, "%llu\n");

static void iommu_debugfs_add(struct iommu_table *tbl)
{
	char name[10];
	struct dentry *liobn_entry;

	sprintf(name, "%08lx", tbl->it_index);
	liobn_entry = debugfs_create_dir(name, iommu_debugfs_dir);

	debugfs_create_file_unsafe("weight", 0400, liobn_entry, tbl, &iommu_debugfs_fops_weight);
	debugfs_create_ulong("it_size", 0400, liobn_entry, &tbl->it_size);
	debugfs_create_ulong("it_page_shift", 0400, liobn_entry, &tbl->it_page_shift);
	debugfs_create_ulong("it_reserved_start", 0400, liobn_entry, &tbl->it_reserved_start);
	debugfs_create_ulong("it_reserved_end", 0400, liobn_entry, &tbl->it_reserved_end);
	debugfs_create_ulong("it_indirect_levels", 0400, liobn_entry, &tbl->it_indirect_levels);
	debugfs_create_ulong("it_level_size", 0400, liobn_entry, &tbl->it_level_size);
}

static void iommu_debugfs_del(struct iommu_table *tbl)
{
	char name[10];
	struct dentry *liobn_entry;

	sprintf(name, "%08lx", tbl->it_index);
	liobn_entry = debugfs_lookup(name, iommu_debugfs_dir);
	debugfs_remove(liobn_entry);
}
#else
static void iommu_debugfs_add(struct iommu_table *tbl){}
static void iommu_debugfs_del(struct iommu_table *tbl){}
#endif

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