Commit 8ada2c1c authored by Shachar Raindel's avatar Shachar Raindel Committed by Roland Dreier

IB/core: Add support for on demand paging regions

* Extend the umem struct to keep the ODP related data.
* Allocate and initialize the ODP related information in the umem
  (page_list, dma_list) and freeing as needed in the end of the run.
* Store a reference to the process PID struct in the ucontext.  Used to
  safely obtain the task_struct and the mm during fault handling,
  without preventing the task destruction if needed.
* Add 2 helper functions: ib_umem_odp_map_dma_pages and
  ib_umem_odp_unmap_dma_pages. These functions get the DMA addresses
  of specific pages of the umem (and, currently, pin them).
* Support for page faults only - IB core will keep the reference on
  the pages used and call put_page when freeing an ODP umem
  area. Invalidations support will be added in a later patch.
Signed-off-by: default avatarSagi Grimberg <sagig@mellanox.com>
Signed-off-by: default avatarShachar Raindel <raindel@mellanox.com>
Signed-off-by: default avatarHaggai Eran <haggaie@mellanox.com>
Signed-off-by: default avatarMajd Dibbiny <majd@mellanox.com>
Signed-off-by: default avatarRoland Dreier <roland@purestorage.com>
parent 860f10a7
......@@ -11,6 +11,7 @@ obj-$(CONFIG_INFINIBAND_USER_ACCESS) += ib_uverbs.o ib_ucm.o \
ib_core-y := packer.o ud_header.o verbs.o sysfs.o \
device.o fmr_pool.o cache.o netlink.o
ib_core-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
ib_core-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += umem_odp.o
ib_mad-y := mad.o smi.o agent.o mad_rmpp.o
......
......@@ -39,6 +39,7 @@
#include <linux/hugetlb.h>
#include <linux/dma-attrs.h>
#include <linux/slab.h>
#include <rdma/ib_umem_odp.h>
#include "uverbs.h"
......@@ -69,6 +70,10 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d
/**
* ib_umem_get - Pin and DMA map userspace memory.
*
* If access flags indicate ODP memory, avoid pinning. Instead, stores
* the mm for future page fault handling.
*
* @context: userspace context to pin memory for
* @addr: userspace virtual address to start at
* @size: length of region to pin
......@@ -117,6 +122,17 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
(IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE |
IB_ACCESS_REMOTE_ATOMIC | IB_ACCESS_MW_BIND));
if (access & IB_ACCESS_ON_DEMAND) {
ret = ib_umem_odp_get(context, umem);
if (ret) {
kfree(umem);
return ERR_PTR(ret);
}
return umem;
}
umem->odp_data = NULL;
/* We assume the memory is from hugetlb until proved otherwise */
umem->hugetlb = 1;
......@@ -237,6 +253,11 @@ void ib_umem_release(struct ib_umem *umem)
struct task_struct *task;
unsigned long diff;
if (umem->odp_data) {
ib_umem_odp_release(umem);
return;
}
__ib_umem_release(umem->context->device, umem, 1);
task = get_pid_task(umem->pid, PIDTYPE_PID);
......@@ -285,6 +306,9 @@ int ib_umem_page_count(struct ib_umem *umem)
int n;
struct scatterlist *sg;
if (umem->odp_data)
return ib_umem_num_pages(umem);
shift = ilog2(umem->page_size);
n = 0;
......
/*
* Copyright (c) 2014 Mellanox Technologies. 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/types.h>
#include <linux/sched.h>
#include <linux/pid.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/vmalloc.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_umem.h>
#include <rdma/ib_umem_odp.h>
int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem)
{
int ret_val;
struct pid *our_pid;
/* Prevent creating ODP MRs in child processes */
rcu_read_lock();
our_pid = get_task_pid(current->group_leader, PIDTYPE_PID);
rcu_read_unlock();
put_pid(our_pid);
if (context->tgid != our_pid)
return -EINVAL;
umem->hugetlb = 0;
umem->odp_data = kzalloc(sizeof(*umem->odp_data), GFP_KERNEL);
if (!umem->odp_data)
return -ENOMEM;
mutex_init(&umem->odp_data->umem_mutex);
umem->odp_data->page_list = vzalloc(ib_umem_num_pages(umem) *
sizeof(*umem->odp_data->page_list));
if (!umem->odp_data->page_list) {
ret_val = -ENOMEM;
goto out_odp_data;
}
umem->odp_data->dma_list = vzalloc(ib_umem_num_pages(umem) *
sizeof(*umem->odp_data->dma_list));
if (!umem->odp_data->dma_list) {
ret_val = -ENOMEM;
goto out_page_list;
}
return 0;
out_page_list:
vfree(umem->odp_data->page_list);
out_odp_data:
kfree(umem->odp_data);
return ret_val;
}
void ib_umem_odp_release(struct ib_umem *umem)
{
/*
* Ensure that no more pages are mapped in the umem.
*
* It is the driver's responsibility to ensure, before calling us,
* that the hardware will not attempt to access the MR any more.
*/
ib_umem_odp_unmap_dma_pages(umem, ib_umem_start(umem),
ib_umem_end(umem));
vfree(umem->odp_data->dma_list);
vfree(umem->odp_data->page_list);
kfree(umem->odp_data);
kfree(umem);
}
/*
* Map for DMA and insert a single page into the on-demand paging page tables.
*
* @umem: the umem to insert the page to.
* @page_index: index in the umem to add the page to.
* @page: the page struct to map and add.
* @access_mask: access permissions needed for this page.
* @current_seq: sequence number for synchronization with invalidations.
* the sequence number is taken from
* umem->odp_data->notifiers_seq.
*
* The function returns -EFAULT if the DMA mapping operation fails.
*
* The page is released via put_page even if the operation failed. For
* on-demand pinning, the page is released whenever it isn't stored in the
* umem.
*/
static int ib_umem_odp_map_dma_single_page(
struct ib_umem *umem,
int page_index,
struct page *page,
u64 access_mask,
unsigned long current_seq)
{
struct ib_device *dev = umem->context->device;
dma_addr_t dma_addr;
int stored_page = 0;
int ret = 0;
mutex_lock(&umem->odp_data->umem_mutex);
if (!(umem->odp_data->dma_list[page_index])) {
dma_addr = ib_dma_map_page(dev,
page,
0, PAGE_SIZE,
DMA_BIDIRECTIONAL);
if (ib_dma_mapping_error(dev, dma_addr)) {
ret = -EFAULT;
goto out;
}
umem->odp_data->dma_list[page_index] = dma_addr | access_mask;
umem->odp_data->page_list[page_index] = page;
stored_page = 1;
} else if (umem->odp_data->page_list[page_index] == page) {
umem->odp_data->dma_list[page_index] |= access_mask;
} else {
pr_err("error: got different pages in IB device and from get_user_pages. IB device page: %p, gup page: %p\n",
umem->odp_data->page_list[page_index], page);
}
out:
mutex_unlock(&umem->odp_data->umem_mutex);
if (!stored_page)
put_page(page);
return ret;
}
/**
* ib_umem_odp_map_dma_pages - Pin and DMA map userspace memory in an ODP MR.
*
* Pins the range of pages passed in the argument, and maps them to
* DMA addresses. The DMA addresses of the mapped pages is updated in
* umem->odp_data->dma_list.
*
* Returns the number of pages mapped in success, negative error code
* for failure.
*
* @umem: the umem to map and pin
* @user_virt: the address from which we need to map.
* @bcnt: the minimal number of bytes to pin and map. The mapping might be
* bigger due to alignment, and may also be smaller in case of an error
* pinning or mapping a page. The actual pages mapped is returned in
* the return value.
* @access_mask: bit mask of the requested access permissions for the given
* range.
* @current_seq: the MMU notifiers sequance value for synchronization with
* invalidations. the sequance number is read from
* umem->odp_data->notifiers_seq before calling this function
*/
int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 user_virt, u64 bcnt,
u64 access_mask, unsigned long current_seq)
{
struct task_struct *owning_process = NULL;
struct mm_struct *owning_mm = NULL;
struct page **local_page_list = NULL;
u64 off;
int j, k, ret = 0, start_idx, npages = 0;
if (access_mask == 0)
return -EINVAL;
if (user_virt < ib_umem_start(umem) ||
user_virt + bcnt > ib_umem_end(umem))
return -EFAULT;
local_page_list = (struct page **)__get_free_page(GFP_KERNEL);
if (!local_page_list)
return -ENOMEM;
off = user_virt & (~PAGE_MASK);
user_virt = user_virt & PAGE_MASK;
bcnt += off; /* Charge for the first page offset as well. */
owning_process = get_pid_task(umem->context->tgid, PIDTYPE_PID);
if (owning_process == NULL) {
ret = -EINVAL;
goto out_no_task;
}
owning_mm = get_task_mm(owning_process);
if (owning_mm == NULL) {
ret = -EINVAL;
goto out_put_task;
}
start_idx = (user_virt - ib_umem_start(umem)) >> PAGE_SHIFT;
k = start_idx;
while (bcnt > 0) {
const size_t gup_num_pages =
min_t(size_t, ALIGN(bcnt, PAGE_SIZE) / PAGE_SIZE,
PAGE_SIZE / sizeof(struct page *));
down_read(&owning_mm->mmap_sem);
/*
* Note: this might result in redundent page getting. We can
* avoid this by checking dma_list to be 0 before calling
* get_user_pages. However, this make the code much more
* complex (and doesn't gain us much performance in most use
* cases).
*/
npages = get_user_pages(owning_process, owning_mm, user_virt,
gup_num_pages,
access_mask & ODP_WRITE_ALLOWED_BIT, 0,
local_page_list, NULL);
up_read(&owning_mm->mmap_sem);
if (npages < 0)
break;
bcnt -= min_t(size_t, npages << PAGE_SHIFT, bcnt);
user_virt += npages << PAGE_SHIFT;
for (j = 0; j < npages; ++j) {
ret = ib_umem_odp_map_dma_single_page(
umem, k, local_page_list[j], access_mask,
current_seq);
if (ret < 0)
break;
k++;
}
if (ret < 0) {
/* Release left over pages when handling errors. */
for (++j; j < npages; ++j)
put_page(local_page_list[j]);
break;
}
}
if (ret >= 0) {
if (npages < 0 && k == start_idx)
ret = npages;
else
ret = k - start_idx;
}
mmput(owning_mm);
out_put_task:
put_task_struct(owning_process);
out_no_task:
free_page((unsigned long)local_page_list);
return ret;
}
EXPORT_SYMBOL(ib_umem_odp_map_dma_pages);
void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 virt,
u64 bound)
{
int idx;
u64 addr;
struct ib_device *dev = umem->context->device;
virt = max_t(u64, virt, ib_umem_start(umem));
bound = min_t(u64, bound, ib_umem_end(umem));
for (addr = virt; addr < bound; addr += (u64)umem->page_size) {
idx = (addr - ib_umem_start(umem)) / PAGE_SIZE;
mutex_lock(&umem->odp_data->umem_mutex);
if (umem->odp_data->page_list[idx]) {
struct page *page = umem->odp_data->page_list[idx];
struct page *head_page = compound_head(page);
dma_addr_t dma = umem->odp_data->dma_list[idx];
dma_addr_t dma_addr = dma & ODP_DMA_ADDR_MASK;
WARN_ON(!dma_addr);
ib_dma_unmap_page(dev, dma_addr, PAGE_SIZE,
DMA_BIDIRECTIONAL);
if (dma & ODP_WRITE_ALLOWED_BIT)
set_page_dirty_lock(head_page);
put_page(page);
}
mutex_unlock(&umem->odp_data->umem_mutex);
}
}
EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages);
......@@ -36,6 +36,7 @@
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <asm/uaccess.h>
......@@ -325,6 +326,9 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file,
INIT_LIST_HEAD(&ucontext->ah_list);
INIT_LIST_HEAD(&ucontext->xrcd_list);
INIT_LIST_HEAD(&ucontext->rule_list);
rcu_read_lock();
ucontext->tgid = get_task_pid(current->group_leader, PIDTYPE_PID);
rcu_read_unlock();
ucontext->closing = 0;
resp.num_comp_vectors = file->device->num_comp_vectors;
......@@ -371,6 +375,7 @@ err_fd:
put_unused_fd(resp.async_fd);
err_free:
put_pid(ucontext->tgid);
ibdev->dealloc_ucontext(ucontext);
err:
......
......@@ -297,6 +297,8 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
kfree(uobj);
}
put_pid(context->tgid);
return context->device->dealloc_ucontext(context);
}
......
......@@ -38,6 +38,7 @@
#include <linux/workqueue.h>
struct ib_ucontext;
struct ib_umem_odp;
struct ib_umem {
struct ib_ucontext *context;
......@@ -50,6 +51,7 @@ struct ib_umem {
struct pid *pid;
struct mm_struct *mm;
unsigned long diff;
struct ib_umem_odp *odp_data;
struct sg_table sg_head;
int nmap;
int npages;
......
/*
* Copyright (c) 2014 Mellanox Technologies. 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.
*/
#ifndef IB_UMEM_ODP_H
#define IB_UMEM_ODP_H
#include <rdma/ib_umem.h>
struct ib_umem_odp {
/*
* An array of the pages included in the on-demand paging umem.
* Indices of pages that are currently not mapped into the device will
* contain NULL.
*/
struct page **page_list;
/*
* An array of the same size as page_list, with DMA addresses mapped
* for pages the pages in page_list. The lower two bits designate
* access permissions. See ODP_READ_ALLOWED_BIT and
* ODP_WRITE_ALLOWED_BIT.
*/
dma_addr_t *dma_list;
/*
* The umem_mutex protects the page_list and dma_list fields of an ODP
* umem, allowing only a single thread to map/unmap pages.
*/
struct mutex umem_mutex;
void *private; /* for the HW driver to use. */
};
#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem);
void ib_umem_odp_release(struct ib_umem *umem);
/*
* The lower 2 bits of the DMA address signal the R/W permissions for
* the entry. To upgrade the permissions, provide the appropriate
* bitmask to the map_dma_pages function.
*
* Be aware that upgrading a mapped address might result in change of
* the DMA address for the page.
*/
#define ODP_READ_ALLOWED_BIT (1<<0ULL)
#define ODP_WRITE_ALLOWED_BIT (1<<1ULL)
#define ODP_DMA_ADDR_MASK (~(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT))
int ib_umem_odp_map_dma_pages(struct ib_umem *umem, u64 start_offset, u64 bcnt,
u64 access_mask, unsigned long current_seq);
void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 start_offset,
u64 bound);
#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
static inline int ib_umem_odp_get(struct ib_ucontext *context,
struct ib_umem *umem)
{
return -EINVAL;
}
static inline void ib_umem_odp_release(struct ib_umem *umem) {}
#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
#endif /* IB_UMEM_ODP_H */
......@@ -1151,6 +1151,8 @@ struct ib_ucontext {
struct list_head xrcd_list;
struct list_head rule_list;
int closing;
struct pid *tgid;
};
struct ib_uobject {
......
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