/*
* Copyright (c) 2005 Topspin Communications. All rights reserved.
* Copyright (c) 2005 Cisco Systems. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* $Id: uverbs_mem.c 2743 2005-06-28 22:27:59Z roland $
*/
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include "uverbs.h"
struct ib_umem_account_work {
struct work_struct work;
struct mm_struct *mm;
unsigned long diff;
};
static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
{
struct ib_umem_chunk *chunk, *tmp;
int i;
list_for_each_entry_safe(chunk, tmp, &umem->chunk_list, list) {
dma_unmap_sg(dev->dma_device, chunk->page_list,
chunk->nents, DMA_BIDIRECTIONAL);
for (i = 0; i < chunk->nents; ++i) {
if (umem->writable && dirty)
set_page_dirty_lock(chunk->page_list[i].page);
put_page(chunk->page_list[i].page);
}
kfree(chunk);
}
}
int ib_umem_get(struct ib_device *dev, struct ib_umem *mem,
void *addr, size_t size, int write)
{
struct page **page_list;
struct ib_umem_chunk *chunk;
unsigned long locked;
unsigned long lock_limit;
unsigned long cur_base;
unsigned long npages;
int ret = 0;
int off;
int i;
if (!can_do_mlock())
return -EPERM;
page_list = (struct page **) __get_free_page(GFP_KERNEL);
if (!page_list)
return -ENOMEM;
mem->user_base = (unsigned long) addr;
mem->length = size;
mem->offset = (unsigned long) addr & ~PAGE_MASK;
mem->page_size = PAGE_SIZE;
mem->writable = write;
INIT_LIST_HEAD(&mem->chunk_list);
npages = PAGE_ALIGN(size + mem->offset) >> PAGE_SHIFT;
down_write(¤t->mm->mmap_sem);
locked = npages + current->mm->locked_vm;
lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
ret = -ENOMEM;
goto out;
}
cur_base = (unsigned long) addr & PAGE_MASK;
while (npages) {
ret = get_user_pages(current, current->mm, cur_base,
min_t(int, npages,
PAGE_SIZE / sizeof (struct page *)),
1, !write, page_list, NULL);
if (ret < 0)
goto out;
cur_base += ret * PAGE_SIZE;
npages -= ret;
off = 0;
while (ret) {
chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) *
min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK),
GFP_KERNEL);
if (!chunk) {
ret = -ENOMEM;
goto out;
}
chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
for (i = 0; i < chunk->nents; ++i) {
chunk->page_list[i].page = page_list[i + off];
chunk->page_list[i].offset = 0;
chunk->page_list[i].length = PAGE_SIZE;
}
chunk->nmap = dma_map_sg(dev->dma_device,
&chunk->page_list[0],
chunk->nents,
DMA_BIDIRECTIONAL);
if (chunk->nmap <= 0) {
for (i = 0; i < chunk->nents; ++i)
put_page(chunk->page_list[i].page);
kfree(chunk);
ret = -ENOMEM;
goto out;
}
ret -= chunk->nents;
off += chunk->nents;
list_add_tail(&chunk->list, &mem->chunk_list);
}
ret = 0;
}
out:
if (ret < 0)
__ib_umem_release(dev, mem, 0);
else
current->mm->locked_vm = locked;
up_write(¤t->mm->mmap_sem);
free_page((unsigned long) page_list);
return ret;
}
void ib_umem_release(struct ib_device *dev, struct ib_umem *umem)
{
__ib_umem_release(dev, umem, 1);
down_write(¤t->mm->mmap_sem);
current->mm->locked_vm -=
PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
up_write(¤t->mm->mmap_sem);
}
static void ib_umem_account(void *work_ptr)
{
struct ib_umem_account_work *work = work_ptr;
down_write(&work->mm->mmap_sem);
work->mm->locked_vm -= work->diff;
up_write(&work->mm->mmap_sem);
mmput(work->mm);
kfree(work);
}
void ib_umem_release_on_close(struct ib_device *dev, struct ib_umem *umem)
{
struct ib_umem_account_work *work;
struct mm_struct *mm;
__ib_umem_release(dev, umem, 1);
mm = get_task_mm(current);
if (!mm)
return;
/*
* We may be called with the mm's mmap_sem already held. This
* can happen when a userspace munmap() is the call that drops
* the last reference to our file and calls our release
* method. If there are memory regions to destroy, we'll end
* up here and not be able to take the mmap_sem. Therefore we
* defer the vm_locked accounting to the system workqueue.
*/
work = kmalloc(sizeof *work, GFP_KERNEL);
if (!work)
return;
INIT_WORK(&work->work, ib_umem_account, work);
work->mm = mm;
work->diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
schedule_work(&work->work);
}
