The new API is an exact match for the needs of radeon. For some reason radeon tries to remove overlapping ranges from the interval tree, but interval trees (and mmu_interval_notifier_insert()) support overlapping ranges directly. Simply delete all this code. Since this driver is missing a invalidate_range_end callback, but still calls get_user_pages(), it cannot be correct against all races. Link: https://lore.kernel.org/r/20191112202231.3856-8-jgg@ziepe.ca Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
		
			
				
	
	
		
			128 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			128 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright 2014 Advanced Micro Devices, Inc.
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|  * All Rights Reserved.
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|  *
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|  * Permission is hereby granted, free of charge, to any person obtaining a
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|  * copy of this software and associated documentation files (the
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|  * "Software"), to deal in the Software without restriction, including
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|  * without limitation the rights to use, copy, modify, merge, publish,
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|  * distribute, sub license, and/or sell copies of the Software, and to
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|  * permit persons to whom the Software is furnished to do so, subject to
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|  * the following conditions:
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|  *
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|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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|  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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|  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
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|  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
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|  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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|  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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|  * USE OR OTHER DEALINGS IN THE SOFTWARE.
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|  *
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|  * The above copyright notice and this permission notice (including the
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|  * next paragraph) shall be included in all copies or substantial portions
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|  * of the Software.
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|  *
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|  */
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| /*
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|  * Authors:
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|  *    Christian König <christian.koenig@amd.com>
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|  */
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| 
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| #include <linux/firmware.h>
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| #include <linux/module.h>
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| #include <linux/mmu_notifier.h>
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| 
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| #include <drm/drm.h>
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| 
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| #include "radeon.h"
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| 
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| /**
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|  * radeon_mn_invalidate - callback to notify about mm change
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|  *
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|  * @mn: our notifier
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|  * @range: the VMA under invalidation
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|  *
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|  * We block for all BOs between start and end to be idle and
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|  * unmap them by move them into system domain again.
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|  */
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| static bool radeon_mn_invalidate(struct mmu_interval_notifier *mn,
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| 				 const struct mmu_notifier_range *range,
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| 				 unsigned long cur_seq)
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| {
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| 	struct radeon_bo *bo = container_of(mn, struct radeon_bo, notifier);
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| 	struct ttm_operation_ctx ctx = { false, false };
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| 	long r;
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| 
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| 	if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound)
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| 		return true;
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| 
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| 	if (!mmu_notifier_range_blockable(range))
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| 		return false;
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| 
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| 	r = radeon_bo_reserve(bo, true);
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| 	if (r) {
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| 		DRM_ERROR("(%ld) failed to reserve user bo\n", r);
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| 		return true;
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| 	}
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| 
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| 	r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
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| 				      MAX_SCHEDULE_TIMEOUT);
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| 	if (r <= 0)
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| 		DRM_ERROR("(%ld) failed to wait for user bo\n", r);
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| 
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| 	radeon_ttm_placement_from_domain(bo, RADEON_GEM_DOMAIN_CPU);
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| 	r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
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| 	if (r)
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| 		DRM_ERROR("(%ld) failed to validate user bo\n", r);
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| 
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| 	radeon_bo_unreserve(bo);
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| 	return true;
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| }
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| 
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| static const struct mmu_interval_notifier_ops radeon_mn_ops = {
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| 	.invalidate = radeon_mn_invalidate,
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| };
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| 
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| /**
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|  * radeon_mn_register - register a BO for notifier updates
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|  *
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|  * @bo: radeon buffer object
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|  * @addr: userptr addr we should monitor
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|  *
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|  * Registers an MMU notifier for the given BO at the specified address.
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|  * Returns 0 on success, -ERRNO if anything goes wrong.
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|  */
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| int radeon_mn_register(struct radeon_bo *bo, unsigned long addr)
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| {
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| 	int ret;
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| 
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| 	ret = mmu_interval_notifier_insert(&bo->notifier, current->mm, addr,
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| 					   radeon_bo_size(bo), &radeon_mn_ops);
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| 	if (ret)
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| 		return ret;
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| 
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| 	/*
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| 	 * FIXME: radeon appears to allow get_user_pages to run during
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| 	 * invalidate_range_start/end, which is not a safe way to read the
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| 	 * PTEs. It should use the mmu_interval_read_begin() scheme around the
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| 	 * get_user_pages to ensure that the PTEs are read properly
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| 	 */
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| 	mmu_interval_read_begin(&bo->notifier);
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| 	return 0;
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| }
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| 
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| /**
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|  * radeon_mn_unregister - unregister a BO for notifier updates
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|  *
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|  * @bo: radeon buffer object
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|  *
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|  * Remove any registration of MMU notifier updates from the buffer object.
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|  */
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| void radeon_mn_unregister(struct radeon_bo *bo)
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| {
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| 	if (!bo->notifier.mm)
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| 		return;
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| 	mmu_interval_notifier_remove(&bo->notifier);
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| 	bo->notifier.mm = NULL;
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| }
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