drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c - arm/linux - Git at Google

 /*
  * Copyright 2014 Advanced Micro Devices, Inc.
  * All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sub license, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * 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 NON-INFRINGEMENT. IN NO EVENT SHALL
  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
  *
  * The above copyright notice and this permission notice (including the
  * next paragraph) shall be included in all copies or substantial portions
  * of the Software.
  *
  */
 /*
  * Authors:
  *    Christian König <christian.koenig@amd.com>
  */

 #include <linux/firmware.h>
 #include <linux/module.h>
 #include <linux/mmu_notifier.h>
 #include <drm/drmP.h>
 #include <drm/drm.h>

 #include "amdgpu.h"

 struct amdgpu_mn {
 	/* constant after initialisation */
 	struct amdgpu_device	*adev;
 	struct mm_struct	*mm;
 	struct mmu_notifier	mn;

 	/* only used on destruction */
 	struct work_struct	work;

 	/* protected by adev->mn_lock */
 	struct hlist_node	node;

 	/* objects protected by lock */
 	struct mutex		lock;
 	struct rb_root		objects;
 };

 struct amdgpu_mn_node {
 	struct interval_tree_node	it;
 	struct list_head		bos;
 };

 /**
  * amdgpu_mn_destroy - destroy the rmn
  *
  * @work: previously sheduled work item
  *
  * Lazy destroys the notifier from a work item
  */
 static void amdgpu_mn_destroy(struct work_struct *work)
 {
 	struct amdgpu_mn *rmn = container_of(work, struct amdgpu_mn, work);
 	struct amdgpu_device *adev = rmn->adev;
 	struct amdgpu_mn_node *node, *next_node;
 	struct amdgpu_bo *bo, *next_bo;

 	mutex_lock(&adev->mn_lock);
 	mutex_lock(&rmn->lock);
 	hash_del(&rmn->node);
 	rbtree_postorder_for_each_entry_safe(node, next_node, &rmn->objects,
 					     it.rb) {
 		list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) {
 			bo->mn = NULL;
 			list_del_init(&bo->mn_list);
 		}
 		kfree(node);
 	}
 	mutex_unlock(&rmn->lock);
 	mutex_unlock(&adev->mn_lock);
 	mmu_notifier_unregister_no_release(&rmn->mn, rmn->mm);
 	kfree(rmn);
 }

 /**
  * amdgpu_mn_release - callback to notify about mm destruction
  *
  * @mn: our notifier
  * @mn: the mm this callback is about
  *
  * Shedule a work item to lazy destroy our notifier.
  */
 static void amdgpu_mn_release(struct mmu_notifier *mn,
 			      struct mm_struct *mm)
 {
 	struct amdgpu_mn *rmn = container_of(mn, struct amdgpu_mn, mn);
 	INIT_WORK(&rmn->work, amdgpu_mn_destroy);
 	schedule_work(&rmn->work);
 }

 /**
  * amdgpu_mn_invalidate_node - unmap all BOs of a node
  *
  * @node: the node with the BOs to unmap
  *
  * We block for all BOs and unmap them by move them
  * into system domain again.
  */
 static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
 				      unsigned long start,
 				      unsigned long end)
 {
 	struct amdgpu_bo *bo;
 	long r;

 	list_for_each_entry(bo, &node->bos, mn_list) {

 		if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start, end))
 			continue;

 		r = amdgpu_bo_reserve(bo, true);
 		if (r) {
 			DRM_ERROR("(%ld) failed to reserve user bo\n", r);
 			continue;
 		}

 		r = reservation_object_wait_timeout_rcu(bo->tbo.resv,
 			true, false, MAX_SCHEDULE_TIMEOUT);
 		if (r <= 0)
 			DRM_ERROR("(%ld) failed to wait for user bo\n", r);

 		amdgpu_ttm_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU);
 		r = ttm_bo_validate(&bo->tbo, &bo->placement, false, false);
 		if (r)
 			DRM_ERROR("(%ld) failed to validate user bo\n", r);

 		amdgpu_bo_unreserve(bo);
 	}
 }

 /**
  * amdgpu_mn_invalidate_page - callback to notify about mm change
  *
  * @mn: our notifier
  * @mn: the mm this callback is about
  * @address: address of invalidate page
  *
  * Invalidation of a single page. Blocks for all BOs mapping it
  * and unmap them by move them into system domain again.
  */
 static void amdgpu_mn_invalidate_page(struct mmu_notifier *mn,
 				      struct mm_struct *mm,
 				      unsigned long address)
 {
 	struct amdgpu_mn *rmn = container_of(mn, struct amdgpu_mn, mn);
 	struct interval_tree_node *it;

 	mutex_lock(&rmn->lock);

 	it = interval_tree_iter_first(&rmn->objects, address, address);
 	if (it) {
 		struct amdgpu_mn_node *node;

 		node = container_of(it, struct amdgpu_mn_node, it);
 		amdgpu_mn_invalidate_node(node, address, address);
 	}

 	mutex_unlock(&rmn->lock);
 }

 /**
  * amdgpu_mn_invalidate_range_start - callback to notify about mm change
  *
  * @mn: our notifier
  * @mn: the mm this callback is about
  * @start: start of updated range
  * @end: end of updated range
  *
  * We block for all BOs between start and end to be idle and
  * unmap them by move them into system domain again.
  */
 static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
 					     struct mm_struct *mm,
 					     unsigned long start,
 					     unsigned long end)
 {
 	struct amdgpu_mn *rmn = container_of(mn, struct amdgpu_mn, mn);
 	struct interval_tree_node *it;

 	/* notification is exclusive, but interval is inclusive */
 	end -= 1;

 	mutex_lock(&rmn->lock);

 	it = interval_tree_iter_first(&rmn->objects, start, end);
 	while (it) {
 		struct amdgpu_mn_node *node;

 		node = container_of(it, struct amdgpu_mn_node, it);
 		it = interval_tree_iter_next(it, start, end);

 		amdgpu_mn_invalidate_node(node, start, end);
 	}

 	mutex_unlock(&rmn->lock);
 }

 static const struct mmu_notifier_ops amdgpu_mn_ops = {
 	.release = amdgpu_mn_release,
 	.invalidate_page = amdgpu_mn_invalidate_page,
 	.invalidate_range_start = amdgpu_mn_invalidate_range_start,
 };

 /**
  * amdgpu_mn_get - create notifier context
  *
  * @adev: amdgpu device pointer
  *
  * Creates a notifier context for current->mm.
  */
 static struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev)
 {
 	struct mm_struct *mm = current->mm;
 	struct amdgpu_mn *rmn;
 	int r;

 	mutex_lock(&adev->mn_lock);
 	if (down_write_killable(&mm->mmap_sem)) {
 		mutex_unlock(&adev->mn_lock);
 		return ERR_PTR(-EINTR);
 	}

 	hash_for_each_possible(adev->mn_hash, rmn, node, (unsigned long)mm)
 		if (rmn->mm == mm)
 			goto release_locks;

 	rmn = kzalloc(sizeof(*rmn), GFP_KERNEL);
 	if (!rmn) {
 		rmn = ERR_PTR(-ENOMEM);
 		goto release_locks;
 	}

 	rmn->adev = adev;
 	rmn->mm = mm;
 	rmn->mn.ops = &amdgpu_mn_ops;
 	mutex_init(&rmn->lock);
 	rmn->objects = RB_ROOT;

 	r = __mmu_notifier_register(&rmn->mn, mm);
 	if (r)
 		goto free_rmn;

 	hash_add(adev->mn_hash, &rmn->node, (unsigned long)mm);

 release_locks:
 	up_write(&mm->mmap_sem);
 	mutex_unlock(&adev->mn_lock);

 	return rmn;

 free_rmn:
 	up_write(&mm->mmap_sem);
 	mutex_unlock(&adev->mn_lock);
 	kfree(rmn);

 	return ERR_PTR(r);
 }

 /**
  * amdgpu_mn_register - register a BO for notifier updates
  *
  * @bo: amdgpu buffer object
  * @addr: userptr addr we should monitor
  *
  * Registers an MMU notifier for the given BO at the specified address.
  * Returns 0 on success, -ERRNO if anything goes wrong.
  */
 int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
 {
 	unsigned long end = addr + amdgpu_bo_size(bo) - 1;
 	struct amdgpu_device *adev = bo->adev;
 	struct amdgpu_mn *rmn;
 	struct amdgpu_mn_node *node = NULL;
 	struct list_head bos;
 	struct interval_tree_node *it;

 	rmn = amdgpu_mn_get(adev);
 	if (IS_ERR(rmn))
 		return PTR_ERR(rmn);

 	INIT_LIST_HEAD(&bos);

 	mutex_lock(&rmn->lock);

 	while ((it = interval_tree_iter_first(&rmn->objects, addr, end))) {
 		kfree(node);
 		node = container_of(it, struct amdgpu_mn_node, it);
 		interval_tree_remove(&node->it, &rmn->objects);
 		addr = min(it->start, addr);
 		end = max(it->last, end);
 		list_splice(&node->bos, &bos);
 	}

 	if (!node) {
 		node = kmalloc(sizeof(struct amdgpu_mn_node), GFP_KERNEL);
 		if (!node) {
 			mutex_unlock(&rmn->lock);
 			return -ENOMEM;
 		}
 	}

 	bo->mn = rmn;

 	node->it.start = addr;
 	node->it.last = end;
 	INIT_LIST_HEAD(&node->bos);
 	list_splice(&bos, &node->bos);
 	list_add(&bo->mn_list, &node->bos);

 	interval_tree_insert(&node->it, &rmn->objects);

 	mutex_unlock(&rmn->lock);

 	return 0;
 }

 /**
  * amdgpu_mn_unregister - unregister a BO for notifier updates
  *
  * @bo: amdgpu buffer object
  *
  * Remove any registration of MMU notifier updates from the buffer object.
  */
 void amdgpu_mn_unregister(struct amdgpu_bo *bo)
 {
 	struct amdgpu_device *adev = bo->adev;
 	struct amdgpu_mn *rmn;
 	struct list_head *head;

 	mutex_lock(&adev->mn_lock);

 	rmn = bo->mn;
 	if (rmn == NULL) {
 		mutex_unlock(&adev->mn_lock);
 		return;
 	}

 	mutex_lock(&rmn->lock);

 	/* save the next list entry for later */
 	head = bo->mn_list.next;

 	bo->mn = NULL;
 	list_del(&bo->mn_list);

 	if (list_empty(head)) {
 		struct amdgpu_mn_node *node;
 		node = container_of(head, struct amdgpu_mn_node, bos);
 		interval_tree_remove(&node->it, &rmn->objects);
 		kfree(node);
 	}

 	mutex_unlock(&rmn->lock);
 	mutex_unlock(&adev->mn_lock);
 }
	/*
	* Copyright 2014 Advanced Micro Devices, Inc.
	* All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the
	* "Software"), to deal in the Software without restriction, including
	* without limitation the rights to use, copy, modify, merge, publish,
	* distribute, sub license, and/or sell copies of the Software, and to
	* permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* 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 NON-INFRINGEMENT. IN NO EVENT SHALL
	* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
	*
	* The above copyright notice and this permission notice (including the
	* next paragraph) shall be included in all copies or substantial portions
	* of the Software.
	*
	*/
	/*
	* Authors:
	* Christian König <christian.koenig@amd.com>
	*/

	#include <linux/firmware.h>
	#include <linux/module.h>
	#include <linux/mmu_notifier.h>
	#include <drm/drmP.h>
	#include <drm/drm.h>

	#include "amdgpu.h"

	struct amdgpu_mn {
	/* constant after initialisation */
	struct amdgpu_device *adev;
	struct mm_struct *mm;
	struct mmu_notifier mn;

	/* only used on destruction */
	struct work_struct work;

	/* protected by adev->mn_lock */
	struct hlist_node node;

	/* objects protected by lock */
	struct mutex lock;
	struct rb_root objects;
	};

	struct amdgpu_mn_node {
	struct interval_tree_node it;
	struct list_head bos;
	};

	/**
	* amdgpu_mn_destroy - destroy the rmn
	*
	* @work: previously sheduled work item
	*
	* Lazy destroys the notifier from a work item
	*/
	static void amdgpu_mn_destroy(struct work_struct *work)
	{
	struct amdgpu_mn *rmn = container_of(work, struct amdgpu_mn, work);
	struct amdgpu_device *adev = rmn->adev;
	struct amdgpu_mn_node node, next_node;
	struct amdgpu_bo bo, next_bo;

	mutex_lock(&adev->mn_lock);
	mutex_lock(&rmn->lock);
	hash_del(&rmn->node);
	rbtree_postorder_for_each_entry_safe(node, next_node, &rmn->objects,
	it.rb) {
	list_for_each_entry_safe(bo, next_bo, &node->bos, mn_list) {
	bo->mn = NULL;
	list_del_init(&bo->mn_list);
	}
	kfree(node);
	}
	mutex_unlock(&rmn->lock);
	mutex_unlock(&adev->mn_lock);
	mmu_notifier_unregister_no_release(&rmn->mn, rmn->mm);
	kfree(rmn);
	}

	/**
	* amdgpu_mn_release - callback to notify about mm destruction
	*
	* @mn: our notifier
	* @mn: the mm this callback is about
	*
	* Shedule a work item to lazy destroy our notifier.
	*/
	static void amdgpu_mn_release(struct mmu_notifier *mn,
	struct mm_struct *mm)
	{
	struct amdgpu_mn *rmn = container_of(mn, struct amdgpu_mn, mn);
	INIT_WORK(&rmn->work, amdgpu_mn_destroy);
	schedule_work(&rmn->work);
	}

	/**
	* amdgpu_mn_invalidate_node - unmap all BOs of a node
	*
	* @node: the node with the BOs to unmap
	*
	* We block for all BOs and unmap them by move them
	* into system domain again.
	*/
	static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node *node,
	unsigned long start,
	unsigned long end)
	{
	struct amdgpu_bo *bo;
	long r;

	list_for_each_entry(bo, &node->bos, mn_list) {

	if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start, end))
	continue;

	r = amdgpu_bo_reserve(bo, true);
	if (r) {
	DRM_ERROR("(%ld) failed to reserve user bo\n", r);
	continue;
	}

	r = reservation_object_wait_timeout_rcu(bo->tbo.resv,
	true, false, MAX_SCHEDULE_TIMEOUT);
	if (r <= 0)
	DRM_ERROR("(%ld) failed to wait for user bo\n", r);

	amdgpu_ttm_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU);
	r = ttm_bo_validate(&bo->tbo, &bo->placement, false, false);
	if (r)
	DRM_ERROR("(%ld) failed to validate user bo\n", r);

	amdgpu_bo_unreserve(bo);
	}
	}

	/**
	* amdgpu_mn_invalidate_page - callback to notify about mm change
	*
	* @mn: our notifier
	* @mn: the mm this callback is about
	* @address: address of invalidate page
	*
	* Invalidation of a single page. Blocks for all BOs mapping it
	* and unmap them by move them into system domain again.
	*/
	static void amdgpu_mn_invalidate_page(struct mmu_notifier *mn,
	struct mm_struct *mm,
	unsigned long address)
	{
	struct amdgpu_mn *rmn = container_of(mn, struct amdgpu_mn, mn);
	struct interval_tree_node *it;

	mutex_lock(&rmn->lock);

	it = interval_tree_iter_first(&rmn->objects, address, address);
	if (it) {
	struct amdgpu_mn_node *node;

	node = container_of(it, struct amdgpu_mn_node, it);
	amdgpu_mn_invalidate_node(node, address, address);
	}

	mutex_unlock(&rmn->lock);
	}

	/**
	* amdgpu_mn_invalidate_range_start - callback to notify about mm change
	*
	* @mn: our notifier
	* @mn: the mm this callback is about
	* @start: start of updated range
	* @end: end of updated range
	*
	* We block for all BOs between start and end to be idle and
	* unmap them by move them into system domain again.
	*/
	static void amdgpu_mn_invalidate_range_start(struct mmu_notifier *mn,
	struct mm_struct *mm,
	unsigned long start,
	unsigned long end)
	{
	struct amdgpu_mn *rmn = container_of(mn, struct amdgpu_mn, mn);
	struct interval_tree_node *it;

	/* notification is exclusive, but interval is inclusive */
	end -= 1;

	mutex_lock(&rmn->lock);

	it = interval_tree_iter_first(&rmn->objects, start, end);
	while (it) {
	struct amdgpu_mn_node *node;

	node = container_of(it, struct amdgpu_mn_node, it);
	it = interval_tree_iter_next(it, start, end);

	amdgpu_mn_invalidate_node(node, start, end);
	}

	mutex_unlock(&rmn->lock);
	}

	static const struct mmu_notifier_ops amdgpu_mn_ops = {
	.release = amdgpu_mn_release,
	.invalidate_page = amdgpu_mn_invalidate_page,
	.invalidate_range_start = amdgpu_mn_invalidate_range_start,
	};

	/**
	* amdgpu_mn_get - create notifier context
	*
	* @adev: amdgpu device pointer
	*
	* Creates a notifier context for current->mm.
	*/
	static struct amdgpu_mn amdgpu_mn_get(struct amdgpu_device adev)
	{
	struct mm_struct *mm = current->mm;
	struct amdgpu_mn *rmn;
	int r;

	mutex_lock(&adev->mn_lock);
	if (down_write_killable(&mm->mmap_sem)) {
	mutex_unlock(&adev->mn_lock);
	return ERR_PTR(-EINTR);
	}

	hash_for_each_possible(adev->mn_hash, rmn, node, (unsigned long)mm)
	if (rmn->mm == mm)
	goto release_locks;

	rmn = kzalloc(sizeof(*rmn), GFP_KERNEL);
	if (!rmn) {
	rmn = ERR_PTR(-ENOMEM);
	goto release_locks;
	}

	rmn->adev = adev;
	rmn->mm = mm;
	rmn->mn.ops = &amdgpu_mn_ops;
	mutex_init(&rmn->lock);
	rmn->objects = RB_ROOT;

	r = __mmu_notifier_register(&rmn->mn, mm);
	if (r)
	goto free_rmn;

	hash_add(adev->mn_hash, &rmn->node, (unsigned long)mm);

	release_locks:
	up_write(&mm->mmap_sem);
	mutex_unlock(&adev->mn_lock);

	return rmn;

	free_rmn:
	up_write(&mm->mmap_sem);
	mutex_unlock(&adev->mn_lock);
	kfree(rmn);

	return ERR_PTR(r);
	}

	/**
	* amdgpu_mn_register - register a BO for notifier updates
	*
	* @bo: amdgpu buffer object
	* @addr: userptr addr we should monitor
	*
	* Registers an MMU notifier for the given BO at the specified address.
	* Returns 0 on success, -ERRNO if anything goes wrong.
	*/
	int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
	{
	unsigned long end = addr + amdgpu_bo_size(bo) - 1;
	struct amdgpu_device *adev = bo->adev;
	struct amdgpu_mn *rmn;
	struct amdgpu_mn_node *node = NULL;
	struct list_head bos;
	struct interval_tree_node *it;

	rmn = amdgpu_mn_get(adev);
	if (IS_ERR(rmn))
	return PTR_ERR(rmn);

	INIT_LIST_HEAD(&bos);

	mutex_lock(&rmn->lock);

	while ((it = interval_tree_iter_first(&rmn->objects, addr, end))) {
	kfree(node);
	node = container_of(it, struct amdgpu_mn_node, it);
	interval_tree_remove(&node->it, &rmn->objects);
	addr = min(it->start, addr);
	end = max(it->last, end);
	list_splice(&node->bos, &bos);
	}

	if (!node) {
	node = kmalloc(sizeof(struct amdgpu_mn_node), GFP_KERNEL);
	if (!node) {
	mutex_unlock(&rmn->lock);
	return -ENOMEM;
	}
	}

	bo->mn = rmn;

	node->it.start = addr;
	node->it.last = end;
	INIT_LIST_HEAD(&node->bos);
	list_splice(&bos, &node->bos);
	list_add(&bo->mn_list, &node->bos);

	interval_tree_insert(&node->it, &rmn->objects);

	mutex_unlock(&rmn->lock);

	return 0;
	}

	/**
	* amdgpu_mn_unregister - unregister a BO for notifier updates
	*
	* @bo: amdgpu buffer object
	*
	* Remove any registration of MMU notifier updates from the buffer object.
	*/
	void amdgpu_mn_unregister(struct amdgpu_bo *bo)
	{
	struct amdgpu_device *adev = bo->adev;
	struct amdgpu_mn *rmn;
	struct list_head *head;

	mutex_lock(&adev->mn_lock);

	rmn = bo->mn;
	if (rmn == NULL) {
	mutex_unlock(&adev->mn_lock);
	return;
	}

	mutex_lock(&rmn->lock);

	/* save the next list entry for later */
	head = bo->mn_list.next;

	bo->mn = NULL;
	list_del(&bo->mn_list);

	if (list_empty(head)) {
	struct amdgpu_mn_node *node;
	node = container_of(head, struct amdgpu_mn_node, bos);
	interval_tree_remove(&node->it, &rmn->objects);
	kfree(node);
	}

	mutex_unlock(&rmn->lock);
	mutex_unlock(&adev->mn_lock);
	}