1/*
  2 * Copyright 2014 Advanced Micro Devices, Inc.
  3 * All Rights Reserved.
  4 *
  5 * Permission is hereby granted, free of charge, to any person obtaining a
  6 * copy of this software and associated documentation files (the
  7 * "Software"), to deal in the Software without restriction, including
  8 * without limitation the rights to use, copy, modify, merge, publish,
  9 * distribute, sub license, and/or sell copies of the Software, and to
 10 * permit persons to whom the Software is furnished to do so, subject to
 11 * the following conditions:
 12 *
 13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 15 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 16 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 17 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 18 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 19 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 20 *
 21 * The above copyright notice and this permission notice (including the
 22 * next paragraph) shall be included in all copies or substantial portions
 23 * of the Software.
 24 *
 25 */
 26/*
 27 * Authors:
 28 *    Christian König <christian.koenig@amd.com>
 29 */
 30
 31/**
 32 * DOC: MMU Notifier
 33 *
 34 * For coherent userptr handling registers an MMU notifier to inform the driver
 35 * about updates on the page tables of a process.
 36 *
 37 * When somebody tries to invalidate the page tables we block the update until
 38 * all operations on the pages in question are completed, then those pages are
 39 * marked as accessed and also dirty if it wasn't a read only access.
 40 *
 41 * New command submissions using the userptrs in question are delayed until all
 42 * page table invalidation are completed and we once more see a coherent process
 43 * address space.
 44 */
 45
 46#include <linux/firmware.h>
 47#include <linux/module.h>
 48#include <drm/drm.h>
 49
 50#include "amdgpu.h"
 51#include "amdgpu_amdkfd.h"
 52
 53/**
 54 * amdgpu_mn_invalidate_gfx - callback to notify about mm change
 55 *
 56 * @mni: the range (mm) is about to update
 57 * @range: details on the invalidation
 58 * @cur_seq: Value to pass to mmu_interval_set_seq()
 59 *
 60 * Block for operations on BOs to finish and mark pages as accessed and
 61 * potentially dirty.
 62 */
 63static bool amdgpu_mn_invalidate_gfx(struct mmu_interval_notifier *mni,
 64				     const struct mmu_notifier_range *range,
 65				     unsigned long cur_seq)
 66{
 67	struct amdgpu_bo *bo = container_of(mni, struct amdgpu_bo, notifier);
 68	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
 69	long r;
 70
 71	if (!mmu_notifier_range_blockable(range))
 72		return false;
 73
 74	mutex_lock(&adev->notifier_lock);
 75
 76	mmu_interval_set_seq(mni, cur_seq);
 77
 78	r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
 79				      MAX_SCHEDULE_TIMEOUT);
 80	mutex_unlock(&adev->notifier_lock);
 81	if (r <= 0)
 82		DRM_ERROR("(%ld) failed to wait for user bo\n", r);
 83	return true;
 84}
 85
 86static const struct mmu_interval_notifier_ops amdgpu_mn_gfx_ops = {
 87	.invalidate = amdgpu_mn_invalidate_gfx,
 88};
 89
 90/**
 91 * amdgpu_mn_invalidate_hsa - callback to notify about mm change
 92 *
 93 * @mni: the range (mm) is about to update
 94 * @range: details on the invalidation
 95 * @cur_seq: Value to pass to mmu_interval_set_seq()
 96 *
 97 * We temporarily evict the BO attached to this range. This necessitates
 98 * evicting all user-mode queues of the process.
 99 */
100static bool amdgpu_mn_invalidate_hsa(struct mmu_interval_notifier *mni,
101				     const struct mmu_notifier_range *range,
102				     unsigned long cur_seq)
103{
104	struct amdgpu_bo *bo = container_of(mni, struct amdgpu_bo, notifier);
105	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
106
107	if (!mmu_notifier_range_blockable(range))
108		return false;
109
110	mutex_lock(&adev->notifier_lock);
111
112	mmu_interval_set_seq(mni, cur_seq);
113
114	amdgpu_amdkfd_evict_userptr(bo->kfd_bo, bo->notifier.mm);
115	mutex_unlock(&adev->notifier_lock);
116
117	return true;
118}
119
120static const struct mmu_interval_notifier_ops amdgpu_mn_hsa_ops = {
121	.invalidate = amdgpu_mn_invalidate_hsa,
122};
123
124/**
125 * amdgpu_mn_register - register a BO for notifier updates
126 *
127 * @bo: amdgpu buffer object
128 * @addr: userptr addr we should monitor
129 *
130 * Registers a mmu_notifier for the given BO at the specified address.
131 * Returns 0 on success, -ERRNO if anything goes wrong.
132 */
133int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
134{
135	if (bo->kfd_bo)
136		return mmu_interval_notifier_insert(&bo->notifier, current->mm,
137						    addr, amdgpu_bo_size(bo),
138						    &amdgpu_mn_hsa_ops);
139	return mmu_interval_notifier_insert(&bo->notifier, current->mm, addr,
140					    amdgpu_bo_size(bo),
141					    &amdgpu_mn_gfx_ops);
142}
143
144/**
145 * amdgpu_mn_unregister - unregister a BO for notifier updates
146 *
147 * @bo: amdgpu buffer object
148 *
149 * Remove any registration of mmu notifier updates from the buffer object.
150 */
151void amdgpu_mn_unregister(struct amdgpu_bo *bo)
152{
153	if (!bo->notifier.mm)
154		return;
155	mmu_interval_notifier_remove(&bo->notifier);
156	bo->notifier.mm = NULL;
157}