/*
* Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
* Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. 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.
*/
#include <linux/mm.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include "ipath_kernel.h"
static void __ipath_release_user_pages(struct page **p, size_t num_pages,
int dirty)
{
size_t i;
for (i = 0; i < num_pages; i++) {
ipath_cdbg(MM, "%lu/%lu put_page %p\n", (unsigned long) i,
(unsigned long) num_pages, p[i]);
if (dirty)
set_page_dirty_lock(p[i]);
put_page(p[i]);
}
}
/* call with current->mm->mmap_sem held */
static int __get_user_pages(unsigned long start_page, size_t num_pages,
struct page **p, struct vm_area_struct **vma)
{
unsigned long lock_limit;
size_t got;
int ret;
lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
if (num_pages > lock_limit) {
ret = -ENOMEM;
goto bail;
}
ipath_cdbg(VERBOSE, "pin %lx pages from vaddr %lx\n",
(unsigned long) num_pages, start_page);
for (got = 0; got < num_pages; got += ret) {
ret = get_user_pages(current, current->mm,
start_page + got * PAGE_SIZE,
num_pages - got, 1, 1,
p + got, vma);
if (ret < 0)
goto bail_release;
}
current->mm->locked_vm += num_pages;
ret = 0;
goto bail;
bail_release:
__ipath_release_user_pages(p, got, 0);
bail:
return ret;
}
/**
* ipath_map_page - a safety wrapper around pci_map_page()
*
* A dma_addr of all 0's is interpreted by the chip as "disabled".
* Unfortunately, it can also be a valid dma_addr returned on some
* architectures.
*
* The powerpc iommu assigns dma_addrs in ascending order, so we don't
* have to bother with retries or mapping a dummy page to insure we
* don't just get the same mapping again.
*
* I'm sure we won't be so lucky with other iommu's, so FIXME.
*/
dma_addr_t ipath_map_page(struct pci_dev *hwdev, struct page *page,
unsigned long offset, size_t size, int direction)
{
dma_addr_t phys;
phys = pci_map_page(hwdev, page, offset, size, direction);
if (phys == 0) {
pci_unmap_page(hwdev, phys, size, direction);
phys = pci_map_page(hwdev, page, offset, size, direction);
/*
* FIXME: If we get 0 again, we should keep this page,
* map another, then free the 0 page.
*/
}
return phys;
}
/**
* ipath_map_single - a safety wrapper around pci_map_single()
*
* Same idea as ipath_map_page().
*/
dma_addr_t ipath_map_single(struct pci_dev *hwdev, void *ptr, size_t size,
int direction)
{
dma_addr_t phys;
phys = pci_map_single(hwdev, ptr, size, direction);
if (phys == 0) {
pci_unmap_single(hwdev, phys, size, direction);
phys = pci_map_single(hwdev, ptr, size, direction);
/*
* FIXME: If we get 0 again, we should keep this page,
* map another, then free the 0 page.
*/
}
return phys;
}
/**
* ipath_get_user_pages - lock user pages into memory
* @start_page: the start page
* @num_pages: the number of pages
* @p: the output page structures
*
* This function takes a given start page (page aligned user virtual
* address) and pins it and the following specified number of pages. For
* now, num_pages is always 1, but that will probably change at some point
* (because caller is doing expected sends on a single virtually contiguous
* buffer, so we can do all pages at once).
*/
int ipath_get_user_pages(unsigned long start_page, size_t num_pages,
struct page **p)
{
int ret;
down_write(¤t->mm->mmap_sem);
ret = __get_user_pages(start_page, num_pages, p, NULL);
up_write(¤t->mm->mmap_sem);
return ret;
}
void ipath_release_user_pages(struct page **p, size_t num_pages)
{
down_write(¤t->mm->mmap_sem);
__ipath_release_user_pages(p, num_pages, 1);
current->mm->locked_vm -= num_pages;
up_write(¤t->mm->mmap_sem);
}
struct ipath_user_pages_work {
struct work_struct work;
struct mm_struct *mm;
unsigned long num_pages;
};
static void user_pages_account(struct work_struct *_work)
{
struct ipath_user_pages_work *work =
container_of(_work, struct ipath_user_pages_work, work);
down_write(&work->mm->mmap_sem);
work->mm->locked_vm -= work->num_pages;
up_write(&work->mm->mmap_sem);
mmput(work->mm);
kfree(work);
}
void ipath_release_user_pages_on_close(struct page **p, size_t num_pages)
{
struct ipath_user_pages_work *work;
struct mm_struct *mm;
__ipath_release_user_pages(p, num_pages, 1);
mm = get_task_mm(current);
if (!mm)
return;
work = kmalloc(sizeof(*work), GFP_KERNEL);
if (!work)
goto bail_mm;
INIT_WORK(&work->work, user_pages_account);
work->mm = mm;
work->num_pages = num_pages;
schedule_work(&work->work);
return;
bail_mm:
mmput(mm);
return;
}
