[linux-block.git] / arch / powerpc / mm / mmu_context_iommu.c

/*
 *  IOMMU helpers in MMU context.
 *
 *  Copyright (C) 2015 IBM Corp. <aik@ozlabs.ru>
 *
 *  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.
 *
 */

#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/rculist.h>
#include <linux/vmalloc.h>
#include <linux/mutex.h>
#include <linux/migrate.h>
#include <linux/hugetlb.h>
#include <linux/swap.h>
#include <asm/mmu_context.h>

static DEFINE_MUTEX(mem_list_mutex);

struct mm_iommu_table_group_mem_t {
	struct list_head next;
	struct rcu_head rcu;
	unsigned long used;
	atomic64_t mapped;
	u64 ua;			/* userspace address */
	u64 entries;		/* number of entries in hpas[] */
	u64 *hpas;		/* vmalloc'ed */
};

static long mm_iommu_adjust_locked_vm(struct mm_struct *mm,
		unsigned long npages, bool incr)
{
	long ret = 0, locked, lock_limit;

	if (!npages)
		return 0;

	down_write(&mm->mmap_sem);

	if (incr) {
		locked = mm->locked_vm + npages;
		lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
		if (locked > lock_limit && !capable(CAP_IPC_LOCK))
			ret = -ENOMEM;
		else
			mm->locked_vm += npages;
	} else {
		if (WARN_ON_ONCE(npages > mm->locked_vm))
			npages = mm->locked_vm;
		mm->locked_vm -= npages;
	}

	pr_debug("[%d] RLIMIT_MEMLOCK HASH64 %c%ld %ld/%ld\n",
			current ? current->pid : 0,
			incr ? '+' : '-',
			npages << PAGE_SHIFT,
			mm->locked_vm << PAGE_SHIFT,
			rlimit(RLIMIT_MEMLOCK));
	up_write(&mm->mmap_sem);

	return ret;
}

bool mm_iommu_preregistered(struct mm_struct *mm)
{
	return !list_empty(&mm->context.iommu_group_mem_list);
}
EXPORT_SYMBOL_GPL(mm_iommu_preregistered);

/*
 * Taken from alloc_migrate_target with changes to remove CMA allocations
 */
struct page *new_iommu_non_cma_page(struct page *page, unsigned long private)
{
	gfp_t gfp_mask = GFP_USER;
	struct page *new_page;

	if (PageCompound(page))
		return NULL;

	if (PageHighMem(page))
		gfp_mask |= __GFP_HIGHMEM;

	/*
	 * We don't want the allocation to force an OOM if possibe
	 */
	new_page = alloc_page(gfp_mask | __GFP_NORETRY | __GFP_NOWARN);
	return new_page;
}

static int mm_iommu_move_page_from_cma(struct page *page)
{
	int ret = 0;
	LIST_HEAD(cma_migrate_pages);

	/* Ignore huge pages for now */
	if (PageCompound(page))
		return -EBUSY;

	lru_add_drain();
	ret = isolate_lru_page(page);
	if (ret)
		return ret;

	list_add(&page->lru, &cma_migrate_pages);
	put_page(page); /* Drop the gup reference */

	ret = migrate_pages(&cma_migrate_pages, new_iommu_non_cma_page,
				NULL, 0, MIGRATE_SYNC, MR_CONTIG_RANGE);
	if (ret) {
		if (!list_empty(&cma_migrate_pages))
			putback_movable_pages(&cma_migrate_pages);
	}

	return 0;
}

long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries,
		struct mm_iommu_table_group_mem_t **pmem)
{
	struct mm_iommu_table_group_mem_t *mem;
	long i, j, ret = 0, locked_entries = 0;
	struct page *page = NULL;

	mutex_lock(&mem_list_mutex);

	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list,
			next) {
		if ((mem->ua == ua) && (mem->entries == entries)) {
			++mem->used;
			*pmem = mem;
			goto unlock_exit;
		}

		/* Overlap? */
		if ((mem->ua < (ua + (entries << PAGE_SHIFT))) &&
				(ua < (mem->ua +
				       (mem->entries << PAGE_SHIFT)))) {
			ret = -EINVAL;
			goto unlock_exit;
		}

	}

	ret = mm_iommu_adjust_locked_vm(mm, entries, true);
	if (ret)
		goto unlock_exit;

	locked_entries = entries;

	mem = kzalloc(sizeof(*mem), GFP_KERNEL);
	if (!mem) {
		ret = -ENOMEM;
		goto unlock_exit;
	}

	mem->hpas = vzalloc(array_size(entries, sizeof(mem->hpas[0])));
	if (!mem->hpas) {
		kfree(mem);
		ret = -ENOMEM;
		goto unlock_exit;
	}

	for (i = 0; i < entries; ++i) {
		if (1 != get_user_pages_fast(ua + (i << PAGE_SHIFT),
					1/* pages */, 1/* iswrite */, &page)) {
			ret = -EFAULT;
			for (j = 0; j < i; ++j)
				put_page(pfn_to_page(mem->hpas[j] >>
						PAGE_SHIFT));
			vfree(mem->hpas);
			kfree(mem);
			goto unlock_exit;
		}
		/*
		 * If we get a page from the CMA zone, since we are going to
		 * be pinning these entries, we might as well move them out
		 * of the CMA zone if possible. NOTE: faulting in + migration
		 * can be expensive. Batching can be considered later
		 */
		if (is_migrate_cma_page(page)) {
			if (mm_iommu_move_page_from_cma(page))
				goto populate;
			if (1 != get_user_pages_fast(ua + (i << PAGE_SHIFT),
						1/* pages */, 1/* iswrite */,
						&page)) {
				ret = -EFAULT;
				for (j = 0; j < i; ++j)
					put_page(pfn_to_page(mem->hpas[j] >>
								PAGE_SHIFT));
				vfree(mem->hpas);
				kfree(mem);
				goto unlock_exit;
			}
		}
populate:
		mem->hpas[i] = page_to_pfn(page) << PAGE_SHIFT;
	}

	atomic64_set(&mem->mapped, 1);
	mem->used = 1;
	mem->ua = ua;
	mem->entries = entries;
	*pmem = mem;

	list_add_rcu(&mem->next, &mm->context.iommu_group_mem_list);

unlock_exit:
	if (locked_entries && ret)
		mm_iommu_adjust_locked_vm(mm, locked_entries, false);

	mutex_unlock(&mem_list_mutex);

	return ret;
}
EXPORT_SYMBOL_GPL(mm_iommu_get);

static void mm_iommu_unpin(struct mm_iommu_table_group_mem_t *mem)
{
	long i;
	struct page *page = NULL;

	for (i = 0; i < mem->entries; ++i) {
		if (!mem->hpas[i])
			continue;

		page = pfn_to_page(mem->hpas[i] >> PAGE_SHIFT);
		if (!page)
			continue;

		put_page(page);
		mem->hpas[i] = 0;
	}
}

static void mm_iommu_do_free(struct mm_iommu_table_group_mem_t *mem)
{

	mm_iommu_unpin(mem);
	vfree(mem->hpas);
	kfree(mem);
}

static void mm_iommu_free(struct rcu_head *head)
{
	struct mm_iommu_table_group_mem_t *mem = container_of(head,
			struct mm_iommu_table_group_mem_t, rcu);

	mm_iommu_do_free(mem);
}

static void mm_iommu_release(struct mm_iommu_table_group_mem_t *mem)
{
	list_del_rcu(&mem->next);
	call_rcu(&mem->rcu, mm_iommu_free);
}

long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem)
{
	long ret = 0;

	mutex_lock(&mem_list_mutex);

	if (mem->used == 0) {
		ret = -ENOENT;
		goto unlock_exit;
	}

	--mem->used;
	/* There are still users, exit */
	if (mem->used)
		goto unlock_exit;

	/* Are there still mappings? */
	if (atomic_cmpxchg(&mem->mapped, 1, 0) != 1) {
		++mem->used;
		ret = -EBUSY;
		goto unlock_exit;
	}

	/* @mapped became 0 so now mappings are disabled, release the region */
	mm_iommu_release(mem);

	mm_iommu_adjust_locked_vm(mm, mem->entries, false);

unlock_exit:
	mutex_unlock(&mem_list_mutex);

	return ret;
}
EXPORT_SYMBOL_GPL(mm_iommu_put);

struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
		unsigned long ua, unsigned long size)
{
	struct mm_iommu_table_group_mem_t *mem, *ret = NULL;

	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) {
		if ((mem->ua <= ua) &&
				(ua + size <= mem->ua +
				 (mem->entries << PAGE_SHIFT))) {
			ret = mem;
			break;
		}
	}

	return ret;
}
EXPORT_SYMBOL_GPL(mm_iommu_lookup);

struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(struct mm_struct *mm,
		unsigned long ua, unsigned long size)
{
	struct mm_iommu_table_group_mem_t *mem, *ret = NULL;

	list_for_each_entry_lockless(mem, &mm->context.iommu_group_mem_list,
			next) {
		if ((mem->ua <= ua) &&
				(ua + size <= mem->ua +
				 (mem->entries << PAGE_SHIFT))) {
			ret = mem;
			break;
		}
	}

	return ret;
}
EXPORT_SYMBOL_GPL(mm_iommu_lookup_rm);

struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,
		unsigned long ua, unsigned long entries)
{
	struct mm_iommu_table_group_mem_t *mem, *ret = NULL;

	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) {
		if ((mem->ua == ua) && (mem->entries == entries)) {
			ret = mem;
			break;
		}
	}

	return ret;
}
EXPORT_SYMBOL_GPL(mm_iommu_find);

long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
		unsigned long ua, unsigned long *hpa)
{
	const long entry = (ua - mem->ua) >> PAGE_SHIFT;
	u64 *va = &mem->hpas[entry];

	if (entry >= mem->entries)
		return -EFAULT;

	*hpa = *va | (ua & ~PAGE_MASK);

	return 0;
}
EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa);

long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
		unsigned long ua, unsigned long *hpa)
{
	const long entry = (ua - mem->ua) >> PAGE_SHIFT;
	void *va = &mem->hpas[entry];
	unsigned long *pa;

	if (entry >= mem->entries)
		return -EFAULT;

	pa = (void *) vmalloc_to_phys(va);
	if (!pa)
		return -EFAULT;

	*hpa = *pa | (ua & ~PAGE_MASK);

	return 0;
}
EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa_rm);

long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem)
{
	if (atomic64_inc_not_zero(&mem->mapped))
		return 0;

	/* Last mm_iommu_put() has been called, no more mappings allowed() */
	return -ENXIO;
}
EXPORT_SYMBOL_GPL(mm_iommu_mapped_inc);

void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem)
{
	atomic64_add_unless(&mem->mapped, -1, 1);
}
EXPORT_SYMBOL_GPL(mm_iommu_mapped_dec);

void mm_iommu_init(struct mm_struct *mm)
{
	INIT_LIST_HEAD_RCU(&mm->context.iommu_group_mem_list);
}
Commit	Line	Data
15b244a8 AK	1	/*
	2	* IOMMU helpers in MMU context.
	3	*
	4	* Copyright (C) 2015 IBM Corp. <aik@ozlabs.ru>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*
	11	*/
	12
3f07c014	13	#include <linux/sched/signal.h>
15b244a8 AK	14	#include <linux/slab.h>
	15	#include <linux/rculist.h>
	16	#include <linux/vmalloc.h>
	17	#include <linux/mutex.h>
2e5bbb54 BS	18	#include <linux/migrate.h>
	19	#include <linux/hugetlb.h>
	20	#include <linux/swap.h>
15b244a8 AK	21	#include <asm/mmu_context.h>
	22
	23	static DEFINE_MUTEX(mem_list_mutex);
	24
	25	struct mm_iommu_table_group_mem_t {
	26	struct list_head next;
	27	struct rcu_head rcu;
	28	unsigned long used;
	29	atomic64_t mapped;
	30	u64 ua; /* userspace address */
	31	u64 entries; /* number of entries in hpas[] */
	32	u64 hpas; / vmalloc'ed */
	33	};
	34
	35	static long mm_iommu_adjust_locked_vm(struct mm_struct *mm,
	36	unsigned long npages, bool incr)
	37	{
	38	long ret = 0, locked, lock_limit;
	39
	40	if (!npages)
	41	return 0;
	42
	43	down_write(&mm->mmap_sem);
	44
	45	if (incr) {
	46	locked = mm->locked_vm + npages;
	47	lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
	48	if (locked > lock_limit && !capable(CAP_IPC_LOCK))
	49	ret = -ENOMEM;
	50	else
	51	mm->locked_vm += npages;
	52	} else {
	53	if (WARN_ON_ONCE(npages > mm->locked_vm))
	54	npages = mm->locked_vm;
	55	mm->locked_vm -= npages;
	56	}
	57
	58	pr_debug("[%d] RLIMIT_MEMLOCK HASH64 %c%ld %ld/%ld\n",
d7baee69	59	current ? current->pid : 0,
15b244a8 AK	60	incr ? '+' : '-',
	61	npages << PAGE_SHIFT,
	62	mm->locked_vm << PAGE_SHIFT,
	63	rlimit(RLIMIT_MEMLOCK));
	64	up_write(&mm->mmap_sem);
	65
	66	return ret;
	67	}
	68
d7baee69	69	bool mm_iommu_preregistered(struct mm_struct *mm)
15b244a8	70	{
d7baee69	71	return !list_empty(&mm->context.iommu_group_mem_list);
15b244a8 AK	72	}
	73	EXPORT_SYMBOL_GPL(mm_iommu_preregistered);
	74
2e5bbb54 BS	75	/*
	76	* Taken from alloc_migrate_target with changes to remove CMA allocations
	77	*/
666feb21	78	struct page new_iommu_non_cma_page(struct page page, unsigned long private)
2e5bbb54 BS	79	{
	80	gfp_t gfp_mask = GFP_USER;
	81	struct page *new_page;
	82
e889e96e	83	if (PageCompound(page))
2e5bbb54 BS	84	return NULL;
	85
	86	if (PageHighMem(page))
	87	gfp_mask \|= __GFP_HIGHMEM;
	88
	89	/*
	90	* We don't want the allocation to force an OOM if possibe
	91	*/
	92	new_page = alloc_page(gfp_mask \| __GFP_NORETRY \| __GFP_NOWARN);
	93	return new_page;
	94	}
	95
	96	static int mm_iommu_move_page_from_cma(struct page *page)
	97	{
	98	int ret = 0;
	99	LIST_HEAD(cma_migrate_pages);
	100
	101	/* Ignore huge pages for now */
e889e96e	102	if (PageCompound(page))
2e5bbb54 BS	103	return -EBUSY;
	104
	105	lru_add_drain();
	106	ret = isolate_lru_page(page);
	107	if (ret)
	108	return ret;
	109
	110	list_add(&page->lru, &cma_migrate_pages);
	111	put_page(page); /* Drop the gup reference */
	112
	113	ret = migrate_pages(&cma_migrate_pages, new_iommu_non_cma_page,
31025351	114	NULL, 0, MIGRATE_SYNC, MR_CONTIG_RANGE);
2e5bbb54 BS	115	if (ret) {
	116	if (!list_empty(&cma_migrate_pages))
	117	putback_movable_pages(&cma_migrate_pages);
	118	}
	119
	120	return 0;
	121	}
	122
d7baee69	123	long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries,
15b244a8 AK	124	struct mm_iommu_table_group_mem_t **pmem)
	125	{
	126	struct mm_iommu_table_group_mem_t *mem;
	127	long i, j, ret = 0, locked_entries = 0;
	128	struct page *page = NULL;
	129
15b244a8 AK	130	mutex_lock(&mem_list_mutex);
15b244a8 AK	131
d7baee69	132	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list,
15b244a8 AK	133	next) {
	134	if ((mem->ua == ua) && (mem->entries == entries)) {
	135	++mem->used;
	136	*pmem = mem;
	137	goto unlock_exit;
	138	}
	139
	140	/* Overlap? */
	141	if ((mem->ua < (ua + (entries << PAGE_SHIFT))) &&
	142	(ua < (mem->ua +
	143	(mem->entries << PAGE_SHIFT)))) {
	144	ret = -EINVAL;
	145	goto unlock_exit;
	146	}
	147
	148	}
	149
d7baee69	150	ret = mm_iommu_adjust_locked_vm(mm, entries, true);
15b244a8 AK	151	if (ret)
	152	goto unlock_exit;
	153
	154	locked_entries = entries;
	155
	156	mem = kzalloc(sizeof(*mem), GFP_KERNEL);
	157	if (!mem) {
	158	ret = -ENOMEM;
	159	goto unlock_exit;
	160	}
	161
fad953ce	162	mem->hpas = vzalloc(array_size(entries, sizeof(mem->hpas[0])));
15b244a8 AK	163	if (!mem->hpas) {
	164	kfree(mem);
	165	ret = -ENOMEM;
	166	goto unlock_exit;
	167	}
	168
	169	for (i = 0; i < entries; ++i) {
	170	if (1 != get_user_pages_fast(ua + (i << PAGE_SHIFT),
	171	1/* pages /, 1/ iswrite */, &page)) {
2e5bbb54	172	ret = -EFAULT;
15b244a8	173	for (j = 0; j < i; ++j)
2e5bbb54 BS	174	put_page(pfn_to_page(mem->hpas[j] >>
2e5bbb54 BS	175	PAGE_SHIFT));
15b244a8 AK	176	vfree(mem->hpas);
15b244a8 AK	177	kfree(mem);
15b244a8 AK	178	goto unlock_exit;
15b244a8 AK	179	}
2e5bbb54 BS	180	/*
	181	* If we get a page from the CMA zone, since we are going to
	182	* be pinning these entries, we might as well move them out
	183	* of the CMA zone if possible. NOTE: faulting in + migration
	184	* can be expensive. Batching can be considered later
	185	*/
a05ef161	186	if (is_migrate_cma_page(page)) {
2e5bbb54 BS	187	if (mm_iommu_move_page_from_cma(page))
	188	goto populate;
	189	if (1 != get_user_pages_fast(ua + (i << PAGE_SHIFT),
	190	1/* pages /, 1/ iswrite */,
	191	&page)) {
	192	ret = -EFAULT;
	193	for (j = 0; j < i; ++j)
	194	put_page(pfn_to_page(mem->hpas[j] >>
	195	PAGE_SHIFT));
	196	vfree(mem->hpas);
	197	kfree(mem);
	198	goto unlock_exit;
	199	}
	200	}
	201	populate:
15b244a8 AK	202	mem->hpas[i] = page_to_pfn(page) << PAGE_SHIFT;
	203	}
	204
	205	atomic64_set(&mem->mapped, 1);
	206	mem->used = 1;
	207	mem->ua = ua;
	208	mem->entries = entries;
	209	*pmem = mem;
	210
d7baee69	211	list_add_rcu(&mem->next, &mm->context.iommu_group_mem_list);
15b244a8 AK	212
	213	unlock_exit:
	214	if (locked_entries && ret)
d7baee69	215	mm_iommu_adjust_locked_vm(mm, locked_entries, false);
15b244a8 AK	216
	217	mutex_unlock(&mem_list_mutex);
	218
	219	return ret;
	220	}
	221	EXPORT_SYMBOL_GPL(mm_iommu_get);
	222
	223	static void mm_iommu_unpin(struct mm_iommu_table_group_mem_t *mem)
	224	{
	225	long i;
	226	struct page *page = NULL;
	227
	228	for (i = 0; i < mem->entries; ++i) {
	229	if (!mem->hpas[i])
	230	continue;
	231
	232	page = pfn_to_page(mem->hpas[i] >> PAGE_SHIFT);
	233	if (!page)
	234	continue;
	235
	236	put_page(page);
	237	mem->hpas[i] = 0;
	238	}
	239	}
	240
	241	static void mm_iommu_do_free(struct mm_iommu_table_group_mem_t *mem)
	242	{
	243
	244	mm_iommu_unpin(mem);
	245	vfree(mem->hpas);
	246	kfree(mem);
	247	}
	248
	249	static void mm_iommu_free(struct rcu_head *head)
	250	{
	251	struct mm_iommu_table_group_mem_t *mem = container_of(head,
	252	struct mm_iommu_table_group_mem_t, rcu);
	253
	254	mm_iommu_do_free(mem);
	255	}
	256
	257	static void mm_iommu_release(struct mm_iommu_table_group_mem_t *mem)
	258	{
	259	list_del_rcu(&mem->next);
15b244a8 AK	260	call_rcu(&mem->rcu, mm_iommu_free);
	261	}
	262
d7baee69	263	long mm_iommu_put(struct mm_struct mm, struct mm_iommu_table_group_mem_t mem)
15b244a8 AK	264	{
	265	long ret = 0;
	266
15b244a8 AK	267	mutex_lock(&mem_list_mutex);
	268
	269	if (mem->used == 0) {
	270	ret = -ENOENT;
	271	goto unlock_exit;
	272	}
	273
	274	--mem->used;
	275	/* There are still users, exit */
	276	if (mem->used)
	277	goto unlock_exit;
	278
	279	/* Are there still mappings? */
	280	if (atomic_cmpxchg(&mem->mapped, 1, 0) != 1) {
	281	++mem->used;
	282	ret = -EBUSY;
	283	goto unlock_exit;
	284	}
	285
	286	/* @mapped became 0 so now mappings are disabled, release the region */
	287	mm_iommu_release(mem);
	288
d7baee69 AK	289	mm_iommu_adjust_locked_vm(mm, mem->entries, false);
d7baee69 AK	290
15b244a8 AK	291	unlock_exit:
	292	mutex_unlock(&mem_list_mutex);
	293
	294	return ret;
	295	}
	296	EXPORT_SYMBOL_GPL(mm_iommu_put);
	297
d7baee69 AK	298	struct mm_iommu_table_group_mem_t mm_iommu_lookup(struct mm_struct mm,
d7baee69 AK	299	unsigned long ua, unsigned long size)
15b244a8 AK	300	{
	301	struct mm_iommu_table_group_mem_t mem, ret = NULL;
	302
d7baee69	303	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) {
15b244a8 AK	304	if ((mem->ua <= ua) &&
	305	(ua + size <= mem->ua +
	306	(mem->entries << PAGE_SHIFT))) {
	307	ret = mem;
	308	break;
	309	}
	310	}
	311
	312	return ret;
	313	}
	314	EXPORT_SYMBOL_GPL(mm_iommu_lookup);
	315
6b5c19c5 AK	316	struct mm_iommu_table_group_mem_t mm_iommu_lookup_rm(struct mm_struct mm,
	317	unsigned long ua, unsigned long size)
	318	{
	319	struct mm_iommu_table_group_mem_t mem, ret = NULL;
	320
	321	list_for_each_entry_lockless(mem, &mm->context.iommu_group_mem_list,
	322	next) {
	323	if ((mem->ua <= ua) &&
	324	(ua + size <= mem->ua +
	325	(mem->entries << PAGE_SHIFT))) {
	326	ret = mem;
	327	break;
	328	}
	329	}
	330
	331	return ret;
	332	}
	333	EXPORT_SYMBOL_GPL(mm_iommu_lookup_rm);
	334
d7baee69 AK	335	struct mm_iommu_table_group_mem_t mm_iommu_find(struct mm_struct mm,
d7baee69 AK	336	unsigned long ua, unsigned long entries)
15b244a8 AK	337	{
	338	struct mm_iommu_table_group_mem_t mem, ret = NULL;
	339
d7baee69	340	list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) {
15b244a8 AK	341	if ((mem->ua == ua) && (mem->entries == entries)) {
	342	ret = mem;
	343	break;
	344	}
	345	}
	346
	347	return ret;
	348	}
	349	EXPORT_SYMBOL_GPL(mm_iommu_find);
	350
	351	long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
	352	unsigned long ua, unsigned long *hpa)
	353	{
	354	const long entry = (ua - mem->ua) >> PAGE_SHIFT;
	355	u64 *va = &mem->hpas[entry];
	356
	357	if (entry >= mem->entries)
	358	return -EFAULT;
	359
	360	hpa = va \| (ua & ~PAGE_MASK);
	361
	362	return 0;
	363	}
	364	EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa);
	365
6b5c19c5 AK	366	long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
	367	unsigned long ua, unsigned long *hpa)
	368	{
	369	const long entry = (ua - mem->ua) >> PAGE_SHIFT;
	370	void *va = &mem->hpas[entry];
	371	unsigned long *pa;
	372
	373	if (entry >= mem->entries)
	374	return -EFAULT;
	375
	376	pa = (void *) vmalloc_to_phys(va);
	377	if (!pa)
	378	return -EFAULT;
	379
	380	hpa = pa \| (ua & ~PAGE_MASK);
	381
	382	return 0;
	383	}
	384	EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa_rm);
	385
15b244a8 AK	386	long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem)
	387	{
	388	if (atomic64_inc_not_zero(&mem->mapped))
	389	return 0;
	390
	391	/* Last mm_iommu_put() has been called, no more mappings allowed() */
	392	return -ENXIO;
	393	}
	394	EXPORT_SYMBOL_GPL(mm_iommu_mapped_inc);
	395
	396	void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem)
	397	{
	398	atomic64_add_unless(&mem->mapped, -1, 1);
	399	}
	400	EXPORT_SYMBOL_GPL(mm_iommu_mapped_dec);
	401
88f54a35	402	void mm_iommu_init(struct mm_struct *mm)
15b244a8	403	{
88f54a35	404	INIT_LIST_HEAD_RCU(&mm->context.iommu_group_mem_list);
15b244a8	405	}