Commit 7f510b46 authored by Bryan O'Sullivan's avatar Bryan O'Sullivan Committed by Roland Dreier
Browse files

IB/ipath: support for userspace apps using core driver



These files introduce a char device that userspace apps use to gain
direct memory-mapped access to the InfiniPath hardware, and routines for
pinning and unpinning user memory in cases where the hardware needs to
DMA into the user address space.
Signed-off-by: default avatarBryan O'Sullivan <bos@pathscale.com>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 3e9b4a5e
This diff is collapsed.
/*
* 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 "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;
#if 0
/*
* XXX - causes MPI programs to fail, haven't had time to check
* yet
*/
if (!capable(CAP_IPC_LOCK)) {
ret = -EPERM;
goto bail;
}
#endif
lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >>
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_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(&current->mm->mmap_sem);
ret = __get_user_pages(start_page, num_pages, p, NULL);
up_write(&current->mm->mmap_sem);
return ret;
}
/**
* ipath_get_user_pages_nocopy - lock a single page for I/O and mark shared
* @start_page: the page to lock
* @p: the output page structure
*
* This is similar to ipath_get_user_pages, but it's always one page, and we
* mark the page as locked for I/O, and shared. This is used for the user
* process page that contains the destination address for the rcvhdrq tail
* update, so we need to have the vma. If we don't do this, the page can be
* taken away from us on fork, even if the child never touches it, and then
* the user process never sees the tail register updates.
*/
int ipath_get_user_pages_nocopy(unsigned long page, struct page **p)
{
struct vm_area_struct *vma;
int ret;
down_write(&current->mm->mmap_sem);
ret = __get_user_pages(page, 1, p, &vma);
up_write(&current->mm->mmap_sem);
return ret;
}
void ipath_release_user_pages(struct page **p, size_t num_pages)
{
down_write(&current->mm->mmap_sem);
__ipath_release_user_pages(p, num_pages, 1);
current->mm->locked_vm -= num_pages;
up_write(&current->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(void *ptr)
{
struct ipath_user_pages_work *work = ptr;
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)
goto bail;
work = kmalloc(sizeof(*work), GFP_KERNEL);
if (!work)
goto bail_mm;
goto bail;
INIT_WORK(&work->work, user_pages_account, work);
work->mm = mm;
work->num_pages = num_pages;
bail_mm:
mmput(mm);
bail:
return;
}
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