drivers/infiniband/core/umem.c - linux - Git at Google

 /*
  * 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;
 	}

 	/* rdma_for_each_block() has a bug if the page size is smaller than the
 	 * page size used to build the umem. For now prevent smaller page sizes
 	 * from being returned.
 	 */
 	pgsz_bitmap &= GENMASK(BITS_PER_LONG - 1, PAGE_SHIFT);

 	/* 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_WRITE;

 	/*
 	 * 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_FORCE;

 	while (npages) {
 		cond_resched();
 		pinned = pin_user_pages_fast(cur_base,
 					  min_t(unsigned long, npages,
 						PAGE_SIZE /
 						sizeof(struct page *)),
 					  gup_flags | FOLL_LONGTERM, 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);
	/*
	* 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;
	}

	/* rdma_for_each_block() has a bug if the page size is smaller than the
	* page size used to build the umem. For now prevent smaller page sizes
	* from being returned.
	*/
	pgsz_bitmap &= GENMASK(BITS_PER_LONG - 1, PAGE_SHIFT);

	/* 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_WRITE;

	/*
	* 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_FORCE;

	while (npages) {
	cond_resched();
	pinned = pin_user_pages_fast(cur_base,
	min_t(unsigned long, npages,
	PAGE_SIZE /
	sizeof(struct page *)),
	gup_flags \| FOLL_LONGTERM, 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);