drm/i915: convert get_user_pages() --> pin_user_pages() (2170ecfa) · Commits · 戴 / test

This code was using get_user_pages*(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Signed-off-by:

John Hubbard <jhubbard@nvidia.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Reviewed-by:

Chris Wilson <chris@chris-wilson.co.uk> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: "Joonas Lahtinen" <joonas.lahtinen@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Matthew Auld <matthew.auld@intel.com> Link: http://lkml.kernel.org/r/20200519002124.2025955-5-jhubbard@nvidia.com Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpu/drm/i915/gem/i915_gem_userptr.c

+13 −9

Original line number	Diff line number	Diff line
		@@ -471,7 +471,7 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work)
		down_read(&mm->mmap_sem);
		locked = 1;
		}
		ret = get_user_pages_remote
		ret = pin_user_pages_remote
		(work->task, mm,
		obj->userptr.ptr + pinned * PAGE_SIZE,
		npages - pinned,
		@@ -507,7 +507,7 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work)
		}
		mutex_unlock(&obj->mm.lock);

		release_pages(pvec, pinned);
		unpin_user_pages(pvec, pinned);
		kvfree(pvec);

		i915_gem_object_put(obj);
		@@ -564,6 +564,7 @@ static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
		struct sg_table *pages;
		bool active;
		int pinned;
		unsigned int gup_flags = 0;

		/* If userspace should engineer that these pages are replaced in
		* the vma between us binding this page into the GTT and completion
		@@ -606,12 +607,15 @@ static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
		*
		* We may or may not care.
		*/
		if (pvec) /* defer to worker if malloc fails */
		pinned = __get_user_pages_fast(obj->userptr.ptr,
		num_pages,
		!i915_gem_object_is_readonly(obj),
		if (pvec) {
		/* defer to worker if malloc fails */
		if (!i915_gem_object_is_readonly(obj))
		gup_flags \|= FOLL_WRITE;
		pinned = pin_user_pages_fast_only(obj->userptr.ptr,
		num_pages, gup_flags,
		pvec);
		}
		}

		active = false;
		if (pinned < 0) {
		@@ -628,7 +632,7 @@ static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
		__i915_gem_userptr_set_active(obj, true);

		if (IS_ERR(pages))
		release_pages(pvec, pinned);
		unpin_user_pages(pvec, pinned);
		kvfree(pvec);

		return PTR_ERR_OR_ZERO(pages);
		@@ -683,7 +687,7 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj,
		}

		mark_page_accessed(page);
		put_page(page);
		unpin_user_page(page);
		}
		obj->mm.dirty = false;

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