/*
* Copyright (c) 2005 Topspin Communications. All rights reserved.
* Copyright (c) 2005 Cisco Systems. All rights reserved.
* Copyright (c) 2005 Mellanox Technologies. All rights reserved.
* Copyright (c) 2020 Intel Corporation. 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/dma-mapping.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/count_zeros.h>
#include <rdma/ib_umem_odp.h>
#include "uverbs.h"
static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
{
bool make_dirty = umem->writable && dirty;
struct scatterlist *sg;
unsigned int i;
if (dirty)
ib_dma_unmap_sgtable_attrs(dev, &umem->sgt_append.sgt,
DMA_BIDIRECTIONAL, 0);
for_each_sgtable_sg(&umem->sgt_append.sgt, sg, i)
unpin_user_page_range_dirty_lock(sg_page(sg),
DIV_ROUND_UP(sg->length, PAGE_SIZE), make_dirty);
sg_free_append_table(&umem->sgt_append);
}
/**
* ib_umem_find_best_pgsz - Find best HW page size to use for this MR
*
* @umem: umem struct
* @pgsz_bitmap: bitmap of HW supported page sizes
* @virt: IOVA
*
* This helper is intended for HW that support multiple page
* sizes but can do only a single page size in an MR.
*
* Returns 0 if the umem requires page sizes not supported by
* the driver to be mapped. Drivers always supporting PAGE_SIZE
* or smaller will never see a 0 result.
*/
unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
unsigned long pgsz_bitmap,
unsigned long virt)
{
struct scatterlist *sg;
unsigned long va, pgoff;
dma_addr_t mask;
int i;
umem->iova = va = virt;
if (umem->is_odp) {
unsigned int page_size = BIT(to_ib_umem_odp(umem)->page_shift);
/* ODP must always be self consistent. */
if (!(pgsz_bitmap & page_size))
return 0;
return page_size;
}
/* The best result is the smallest page size that results in the minimum
* number of required pages. Compute the largest page size that could
* work based on VA address bits that don't change.
*/
mask = pgsz_bitmap &
GENMASK(BITS_PER_LONG - 1,
bits_per((umem->length - 1 + virt) ^ virt));
/* offset into first SGL */
pgoff = umem->address & ~PAGE_MASK;
for_each_sgtable_dma_sg(&umem->sgt_append.sgt, sg, i) {
/* Walk SGL and reduce max page size if VA/PA bits differ
* for any address.
*/
mask |= (sg_dma_address(sg) + pgoff) ^ va;
va += sg_dma_len(sg) - pgoff;
/* Except for the last entry, the ending iova alignment sets
* the maximum possible page size as the low bits of the iova
* must be zero when starting the next chunk.
*/
if (i != (umem->sgt_append.sgt.nents - 1))
mask |= va;
pgoff = 0;
}
/* The mask accumulates 1's in each position where the VA and physical
* address differ, thus the length of trailing 0 is the largest page
* size that can pass the VA through to the physical.
*/
if (mask)
pgsz_bitmap &= GENMASK(count_trailing_zeros(mask), 0);
return pgsz_bitmap ? rounddown_pow_of_two(pgsz_bitmap) : 0;
}
EXPORT_SYMBOL(ib_umem_find_best_pgsz);
/**
* ib_umem_get - Pin and DMA map userspace memory.
*
* @device: IB device to connect UMEM
* @addr: userspace virtual address to start at
* @size: length of region to pin
* @access: IB_ACCESS_xxx flags for memory being pinned
*/
struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
size_t size, int access)
{
struct ib_umem *umem;
struct page **page_list;
unsigned long lock_limit;
unsigned long new_pinned;
unsigned long cur_base;
unsigned long dma_attr = 0;
struct mm_struct *mm;
unsigned long npages;
int pinned, ret;
unsigned int gup_flags = FOLL_LONGTERM;
/*
* If the combination of the addr and size requested for this memory
* region causes an integer overflow, return error.
*/
if (((addr + size) < addr) ||
PAGE_ALIGN(addr + size) < (addr + size))
return ERR_PTR(-EINVAL);
if (!can_do_mlock())
return ERR_PTR(-EPERM);
if (access & IB_ACCESS_ON_DEMAND)
return ERR_PTR(-EOPNOTSUPP);
umem = kzalloc(sizeof(*umem), GFP_KERNEL);
if (!umem)
return ERR_PTR(-ENOMEM);
umem->ibdev = device;
umem->length = size;
umem->address = addr;
/*
* Drivers should call ib_umem_find_best_pgsz() to set the iova
* correctly.
*/
umem->iova = addr;
umem->writable = ib_access_writable(access);
umem->owning_mm = mm = current->mm;
mmgrab(mm);
page_list = (struct page **) __get_free_page(GFP_KERNEL);
if (!page_list) {
ret = -ENOMEM;
goto umem_kfree;
}
npages = ib_umem_num_pages(umem);
if (npages == 0 || npages > UINT_MAX) {
ret = -EINVAL;
goto out;
}
lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
new_pinned = atomic64_add_return(npages, &mm->pinned_vm);
if (new_pinned > lock_limit && !capable(CAP_IPC_LOCK)) {
atomic64_sub(npages, &mm->pinned_vm);
ret = -ENOMEM;
goto out;
}
cur_base = addr & PAGE_MASK;
if (umem->writable)
gup_flags |= FOLL_WRITE;
while (npages) {
cond_resched();
pinned = pin_user_pages_fast(cur_base,
min_t(unsigned long, npages,
PAGE_SIZE /
sizeof(struct page *)),
gup_flags, page_list);
if (pinned < 0) {
ret = pinned;
goto umem_release;
}
cur_base += pinned * PAGE_SIZE;
npages -= pinned;
ret = sg_alloc_append_table_from_pages(
&umem->sgt_append, page_list, pinned, 0,
pinned << PAGE_SHIFT, ib_dma_max_seg_size(device),
npages, GFP_KERNEL);
if (ret) {
unpin_user_pages_dirty_lock(page_list, pinned, 0);
goto umem_release;
}
}
if (access & IB_ACCESS_RELAXED_ORDERING)
dma_attr |= DMA_ATTR_WEAK_ORDERING;
ret = ib_dma_map_sgtable_attrs(device, &umem->sgt_append.sgt,
DMA_BIDIRECTIONAL, dma_attr);
if (ret)
goto umem_release;
goto out;
umem_release:
__ib_umem_release(device, umem, 0);
atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm);
out:
free_page((unsigned long) page_list);
umem_kfree:
if (ret) {
mmdrop(umem->owning_mm);
kfree(umem);
}
return ret ? ERR_PTR(ret) : umem;
}
EXPORT_SYMBOL(ib_umem_get);
/**
* ib_umem_release - release memory pinned with ib_umem_get
* @umem: umem struct to release
*/
void ib_umem_release(struct ib_umem *umem)
{
if (!umem)
return;
if (umem->is_dmabuf)
return ib_umem_dmabuf_release(to_ib_umem_dmabuf(umem));
if (umem->is_odp)
return ib_umem_odp_release(to_ib_umem_odp(umem));
__ib_umem_release(umem->ibdev, umem, 1);
atomic64_sub(ib_umem_num_pages(umem), &umem->owning_mm->pinned_vm);
mmdrop(umem->owning_mm);
kfree(umem);
}
EXPORT_SYMBOL(ib_umem_release);
/*
* Copy from the given ib_umem's pages to the given buffer.
*
* umem - the umem to copy from
* offset - offset to start copying from
* dst - destination buffer
* length - buffer length
*
* Returns 0 on success, or an error code.
*/
int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset,
size_t length)
{
size_t end = offset + length;
int ret;
if (offset > umem->length || length > umem->length - offset) {
pr_err("%s not in range. offset: %zd umem length: %zd end: %zd\n",
__func__, offset, umem->length, end);
return -EINVAL;
}
ret = sg_pcopy_to_buffer(umem->sgt_append.sgt.sgl,
umem->sgt_append.sgt.orig_nents, dst, length,
offset + ib_umem_offset(umem));
if (ret < 0)
return ret;
else if (ret != length)
return -EINVAL;
else
return 0;
}
EXPORT_SYMBOL(ib_umem_copy_from);
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