368 lines
8.0 KiB
C
368 lines
8.0 KiB
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.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,
|
||
|
|
int **resultp)
|
||
|
|
{
|
||
|
|
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_CMA);
|
||
|
|
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(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_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_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);
|
||
|
|
}
|