On Tue, Mar 23, 2021 at 04:50:05PM +0100, Maarten Lankhorst wrote:
> Instead of doing what we do currently, which will never work with
> PROVE_LOCKING, do the same as AMD does, and something similar to
> relocation slowpath. When all locks are dropped, we acquire the
> pages for pinning. When the locks are taken, we transfer those
> pages in .get_pages() to the bo. As a final check before installing
> the fences, we ensure that the mmu notifier was not called; if it is,
> we return -EAGAIN to userspace to signal it has to start over.
>
> Changes since v1:
> - Unbinding is done in submit_init only. submit_begin() removed.
> - MMU_NOTFIER -> MMU_NOTIFIER
> Changes since v2:
> - Make i915->mm.notifier a spinlock.
> Changes since v3:
> - Add WARN_ON if there are any page references left, should have been 0.
> - Return 0 on success in submit_init(), bug from spinlock conversion.
> - Release pvec outside of notifier_lock (Thomas).
> Changes since v4:
> - Mention why we're clearing eb->[i + 1].vma in the code. (Thomas)
> - Actually check all invalidations in eb_move_to_gpu. (Thomas)
> - Do not wait when process is exiting to fix gem_ctx_persistence.userptr.
> Changes since v5:
> - Clarify why check on PF_EXITING is (temporarily) required.
> Changes since v6:
> - Ensure userptr validity is checked in set_domain through a special path.
>
> Signed-off-by: Maarten Lankhorst <maarten.lankho...@linux.intel.com>
> Acked-by: Dave Airlie <airl...@redhat.com>
> ---
> drivers/gpu/drm/i915/gem/i915_gem_domain.c | 18 +-
> .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 101 ++-
> drivers/gpu/drm/i915/gem/i915_gem_object.h | 38 +-
> .../gpu/drm/i915/gem/i915_gem_object_types.h | 10 +-
> drivers/gpu/drm/i915/gem/i915_gem_pages.c | 2 +-
> drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 796 ++++++------------
> drivers/gpu/drm/i915/i915_drv.h | 9 +-
> drivers/gpu/drm/i915/i915_gem.c | 5 +-
> 8 files changed, 395 insertions(+), 584 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c
> b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
> index 2f4980bf742e..76cb9f5c66aa 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
> @@ -468,14 +468,28 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void
> *data,
> if (!obj)
> return -ENOENT;
>
> + if (i915_gem_object_is_userptr(obj)) {
> + /*
> + * Try to grab userptr pages, iris uses set_domain to check
> + * userptr validity
> + */
> + err = i915_gem_object_userptr_validate(obj);
> + if (!err)
> + err = i915_gem_object_wait(obj,
> + I915_WAIT_INTERRUPTIBLE |
> + I915_WAIT_PRIORITY |
> + (write_domain ?
> I915_WAIT_ALL : 0),
> + MAX_SCHEDULE_TIMEOUT);
> + goto out;
> + }
> +
> /*
> * Proxy objects do not control access to the backing storage, ergo
> * they cannot be used as a means to manipulate the cache domain
> * tracking for that backing storage. The proxy object is always
> * considered to be outside of any cache domain.
> */
> - if (i915_gem_object_is_proxy(obj) &&
> - !i915_gem_object_is_userptr(obj)) {
> + if (i915_gem_object_is_proxy(obj)) {
> err = -ENXIO;
> goto out;
> }
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index 795c68fcc6ed..b5ca9eb53565 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -53,14 +53,16 @@ enum {
> /* __EXEC_OBJECT_NO_RESERVE is BIT(31), defined in i915_vma.h */
> #define __EXEC_OBJECT_HAS_PIN BIT(30)
> #define __EXEC_OBJECT_HAS_FENCE BIT(29)
> -#define __EXEC_OBJECT_NEEDS_MAP BIT(28)
> -#define __EXEC_OBJECT_NEEDS_BIAS BIT(27)
> -#define __EXEC_OBJECT_INTERNAL_FLAGS (~0u << 27) /* all of the above + */
> +#define __EXEC_OBJECT_USERPTR_INIT BIT(28)
> +#define __EXEC_OBJECT_NEEDS_MAP BIT(27)
> +#define __EXEC_OBJECT_NEEDS_BIAS BIT(26)
> +#define __EXEC_OBJECT_INTERNAL_FLAGS (~0u << 26) /* all of the above + */
> #define __EXEC_OBJECT_RESERVED (__EXEC_OBJECT_HAS_PIN |
> __EXEC_OBJECT_HAS_FENCE)
>
> #define __EXEC_HAS_RELOC BIT(31)
> #define __EXEC_ENGINE_PINNED BIT(30)
> -#define __EXEC_INTERNAL_FLAGS (~0u << 30)
> +#define __EXEC_USERPTR_USED BIT(29)
> +#define __EXEC_INTERNAL_FLAGS (~0u << 29)
> #define UPDATE PIN_OFFSET_FIXED
>
> #define BATCH_OFFSET_BIAS (256*1024)
> @@ -871,6 +873,26 @@ static int eb_lookup_vmas(struct i915_execbuffer *eb)
> }
>
> eb_add_vma(eb, i, batch, vma);
> +
> + if (i915_gem_object_is_userptr(vma->obj)) {
> + err = i915_gem_object_userptr_submit_init(vma->obj);
> + if (err) {
> + if (i + 1 < eb->buffer_count) {
> + /*
> + * Execbuffer code expects last vma
> entry to be NULL,
> + * since we already initialized this
> entry,
> + * set the next value to NULL or we
> mess up
> + * cleanup handling.
> + */
> + eb->vma[i + 1].vma = NULL;
> + }
> +
> + return err;
> + }
> +
> + eb->vma[i].flags |= __EXEC_OBJECT_USERPTR_INIT;
> + eb->args->flags |= __EXEC_USERPTR_USED;
> + }
> }
>
> if (unlikely(eb->batch->flags & EXEC_OBJECT_WRITE)) {
> @@ -972,7 +994,7 @@ eb_get_vma(const struct i915_execbuffer *eb, unsigned
> long handle)
> }
> }
>
> -static void eb_release_vmas(struct i915_execbuffer *eb, bool final)
> +static void eb_release_vmas(struct i915_execbuffer *eb, bool final, bool
> release_userptr)
> {
> const unsigned int count = eb->buffer_count;
> unsigned int i;
> @@ -986,6 +1008,11 @@ static void eb_release_vmas(struct i915_execbuffer *eb,
> bool final)
>
> eb_unreserve_vma(ev);
>
> + if (release_userptr && ev->flags & __EXEC_OBJECT_USERPTR_INIT) {
> + ev->flags &= ~__EXEC_OBJECT_USERPTR_INIT;
> + i915_gem_object_userptr_submit_fini(vma->obj);
> + }
> +
> if (final)
> i915_vma_put(vma);
> }
> @@ -1916,6 +1943,31 @@ static int eb_prefault_relocations(const struct
> i915_execbuffer *eb)
> return 0;
> }
>
> +static int eb_reinit_userptr(struct i915_execbuffer *eb)
> +{
> + const unsigned int count = eb->buffer_count;
> + unsigned int i;
> + int ret;
> +
> + if (likely(!(eb->args->flags & __EXEC_USERPTR_USED)))
> + return 0;
> +
> + for (i = 0; i < count; i++) {
> + struct eb_vma *ev = &eb->vma[i];
> +
> + if (!i915_gem_object_is_userptr(ev->vma->obj))
> + continue;
> +
> + ret = i915_gem_object_userptr_submit_init(ev->vma->obj);
> + if (ret)
> + return ret;
> +
> + ev->flags |= __EXEC_OBJECT_USERPTR_INIT;
> + }
> +
> + return 0;
> +}
> +
> static noinline int eb_relocate_parse_slow(struct i915_execbuffer *eb,
> struct i915_request *rq)
> {
> @@ -1930,7 +1982,7 @@ static noinline int eb_relocate_parse_slow(struct
> i915_execbuffer *eb,
> }
>
> /* We may process another execbuffer during the unlock... */
> - eb_release_vmas(eb, false);
> + eb_release_vmas(eb, false, true);
> i915_gem_ww_ctx_fini(&eb->ww);
>
> if (rq) {
> @@ -1971,10 +2023,8 @@ static noinline int eb_relocate_parse_slow(struct
> i915_execbuffer *eb,
> err = 0;
> }
>
> -#ifdef CONFIG_MMU_NOTIFIER
> if (!err)
> - flush_workqueue(eb->i915->mm.userptr_wq);
> -#endif
> + err = eb_reinit_userptr(eb);
>
> err_relock:
> i915_gem_ww_ctx_init(&eb->ww, true);
> @@ -2036,7 +2086,7 @@ static noinline int eb_relocate_parse_slow(struct
> i915_execbuffer *eb,
>
> err:
> if (err == -EDEADLK) {
> - eb_release_vmas(eb, false);
> + eb_release_vmas(eb, false, false);
> err = i915_gem_ww_ctx_backoff(&eb->ww);
> if (!err)
> goto repeat_validate;
> @@ -2133,7 +2183,7 @@ static int eb_relocate_parse(struct i915_execbuffer *eb)
>
> err:
> if (err == -EDEADLK) {
> - eb_release_vmas(eb, false);
> + eb_release_vmas(eb, false, false);
> err = i915_gem_ww_ctx_backoff(&eb->ww);
> if (!err)
> goto retry;
> @@ -2208,6 +2258,30 @@ static int eb_move_to_gpu(struct i915_execbuffer *eb)
> flags |
> __EXEC_OBJECT_NO_RESERVE);
> }
>
> +#ifdef CONFIG_MMU_NOTIFIER
> + if (!err && (eb->args->flags & __EXEC_USERPTR_USED)) {
> + spin_lock(&eb->i915->mm.notifier_lock);
> +
> + /*
> + * count is always at least 1, otherwise __EXEC_USERPTR_USED
> + * could not have been set
> + */
> + for (i = 0; i < count; i++) {
> + struct eb_vma *ev = &eb->vma[i];
> + struct drm_i915_gem_object *obj = ev->vma->obj;
> +
> + if (!i915_gem_object_is_userptr(obj))
> + continue;
> +
> + err = i915_gem_object_userptr_submit_done(obj);
> + if (err)
> + break;
> + }
> +
> + spin_unlock(&eb->i915->mm.notifier_lock);
> + }
> +#endif
> +
> if (unlikely(err))
> goto err_skip;
>
> @@ -3352,7 +3426,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>
> err = eb_lookup_vmas(&eb);
> if (err) {
> - eb_release_vmas(&eb, true);
> + eb_release_vmas(&eb, true, true);
> goto err_engine;
> }
>
> @@ -3424,6 +3498,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>
> trace_i915_request_queue(eb.request, eb.batch_flags);
> err = eb_submit(&eb, batch);
> +
> err_request:
> i915_request_get(eb.request);
> err = eb_request_add(&eb, err);
> @@ -3444,7 +3519,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
> i915_request_put(eb.request);
>
> err_vma:
> - eb_release_vmas(&eb, true);
> + eb_release_vmas(&eb, true, true);
> if (eb.trampoline)
> i915_vma_unpin(eb.trampoline);
> WARN_ON(err == -EDEADLK);
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h
> b/drivers/gpu/drm/i915/gem/i915_gem_object.h
> index 69509dbd01c7..b5af9c440ac5 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
> @@ -59,6 +59,7 @@ i915_gem_object_create_shmem_from_data(struct
> drm_i915_private *i915,
> const void *data, resource_size_t size);
>
> extern const struct drm_i915_gem_object_ops i915_gem_shmem_ops;
> +
> void __i915_gem_object_release_shmem(struct drm_i915_gem_object *obj,
> struct sg_table *pages,
> bool needs_clflush);
> @@ -278,12 +279,6 @@ i915_gem_object_never_mmap(const struct
> drm_i915_gem_object *obj)
> return i915_gem_object_type_has(obj, I915_GEM_OBJECT_NO_MMAP);
> }
>
> -static inline bool
> -i915_gem_object_needs_async_cancel(const struct drm_i915_gem_object *obj)
> -{
> - return i915_gem_object_type_has(obj, I915_GEM_OBJECT_ASYNC_CANCEL);
> -}
> -
> static inline bool
> i915_gem_object_is_framebuffer(const struct drm_i915_gem_object *obj)
> {
> @@ -573,16 +568,6 @@ void __i915_gem_object_flush_frontbuffer(struct
> drm_i915_gem_object *obj,
> void __i915_gem_object_invalidate_frontbuffer(struct drm_i915_gem_object
> *obj,
> enum fb_op_origin origin);
>
> -static inline bool
> -i915_gem_object_is_userptr(struct drm_i915_gem_object *obj)
> -{
> -#ifdef CONFIG_MMU_NOTIFIER
> - return obj->userptr.mm;
> -#else
> - return false;
> -#endif
> -}
> -
> static inline void
> i915_gem_object_flush_frontbuffer(struct drm_i915_gem_object *obj,
> enum fb_op_origin origin)
> @@ -603,4 +588,25 @@ int i915_gem_object_read_from_page(struct
> drm_i915_gem_object *obj, u64 offset,
>
> bool i915_gem_object_is_shmem(const struct drm_i915_gem_object *obj);
>
> +#ifdef CONFIG_MMU_NOTIFIER
> +static inline bool
> +i915_gem_object_is_userptr(struct drm_i915_gem_object *obj)
> +{
> + return obj->userptr.notifier.mm;
> +}
> +
> +int i915_gem_object_userptr_submit_init(struct drm_i915_gem_object *obj);
> +int i915_gem_object_userptr_submit_done(struct drm_i915_gem_object *obj);
> +void i915_gem_object_userptr_submit_fini(struct drm_i915_gem_object *obj);
> +int i915_gem_object_userptr_validate(struct drm_i915_gem_object *obj);
> +#else
> +static inline bool i915_gem_object_is_userptr(struct drm_i915_gem_object
> *obj) { return false; }
> +
> +static inline int i915_gem_object_userptr_submit_init(struct
> drm_i915_gem_object *obj) { GEM_BUG_ON(1); return -ENODEV; }
> +static inline int i915_gem_object_userptr_submit_done(struct
> drm_i915_gem_object *obj) { GEM_BUG_ON(1); return -ENODEV; }
> +static inline void i915_gem_object_userptr_submit_fini(struct
> drm_i915_gem_object *obj) { GEM_BUG_ON(1); }
> +static inline int i915_gem_object_userptr_validate(struct
> drm_i915_gem_object *obj) { GEM_BUG_ON(1); return -ENODEV; }
> +
> +#endif
> +
> #endif
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> index 414322619781..4c0a34231623 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> @@ -7,6 +7,8 @@
> #ifndef __I915_GEM_OBJECT_TYPES_H__
> #define __I915_GEM_OBJECT_TYPES_H__
>
> +#include <linux/mmu_notifier.h>
> +
> #include <drm/drm_gem.h>
> #include <uapi/drm/i915_drm.h>
>
> @@ -34,7 +36,6 @@ struct drm_i915_gem_object_ops {
> #define I915_GEM_OBJECT_IS_SHRINKABLE BIT(2)
> #define I915_GEM_OBJECT_IS_PROXY BIT(3)
> #define I915_GEM_OBJECT_NO_MMAP BIT(4)
> -#define I915_GEM_OBJECT_ASYNC_CANCEL BIT(5)
>
> /* Interface between the GEM object and its backing storage.
> * get_pages() is called once prior to the use of the associated set
> @@ -299,10 +300,11 @@ struct drm_i915_gem_object {
> #ifdef CONFIG_MMU_NOTIFIER
> struct i915_gem_userptr {
> uintptr_t ptr;
> + unsigned long notifier_seq;
>
> - struct i915_mm_struct *mm;
> - struct i915_mmu_object *mmu_object;
> - struct work_struct *work;
> + struct mmu_interval_notifier notifier;
> + struct page **pvec;
> + int page_ref;
> } userptr;
> #endif
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> index bf61b88a2113..e7d7650072c5 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> @@ -226,7 +226,7 @@ int __i915_gem_object_put_pages(struct
> drm_i915_gem_object *obj)
> * get_pages backends we should be better able to handle the
> * cancellation of the async task in a more uniform manner.
> */
> - if (!pages && !i915_gem_object_needs_async_cancel(obj))
> + if (!pages)
> pages = ERR_PTR(-EINVAL);
>
> if (!IS_ERR(pages))
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> index b466ab2def4d..1e42fbc68697 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> @@ -2,10 +2,39 @@
> * SPDX-License-Identifier: MIT
> *
> * Copyright © 2012-2014 Intel Corporation
> + *
> + * Based on amdgpu_mn, which bears the following notice:
> + *
> + * 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.koe...@amd.com>
> */
>
> #include <linux/mmu_context.h>
> -#include <linux/mmu_notifier.h>
> #include <linux/mempolicy.h>
> #include <linux/swap.h>
> #include <linux/sched/mm.h>
> @@ -15,373 +44,121 @@
> #include "i915_gem_object.h"
> #include "i915_scatterlist.h"
>
> -#if defined(CONFIG_MMU_NOTIFIER)
> -
> -struct i915_mm_struct {
> - struct mm_struct *mm;
> - struct drm_i915_private *i915;
> - struct i915_mmu_notifier *mn;
> - struct hlist_node node;
> - struct kref kref;
> - struct rcu_work work;
> -};
> -
> -#include <linux/interval_tree.h>
> -
> -struct i915_mmu_notifier {
> - spinlock_t lock;
> - struct hlist_node node;
> - struct mmu_notifier mn;
> - struct rb_root_cached objects;
> - struct i915_mm_struct *mm;
> -};
> -
> -struct i915_mmu_object {
> - struct i915_mmu_notifier *mn;
> - struct drm_i915_gem_object *obj;
> - struct interval_tree_node it;
> -};
> +#ifdef CONFIG_MMU_NOTIFIER
>
> -static void add_object(struct i915_mmu_object *mo)
> +/**
> + * i915_gem_userptr_invalidate - callback to notify about mm change
> + *
> + * @mni: the range (mm) is about to update
> + * @range: details on the invalidation
> + * @cur_seq: Value to pass to mmu_interval_set_seq()
> + *
> + * Block for operations on BOs to finish and mark pages as accessed and
> + * potentially dirty.
> + */
> +static bool i915_gem_userptr_invalidate(struct mmu_interval_notifier *mni,
> + const struct mmu_notifier_range *range,
> + unsigned long cur_seq)
> {
> - GEM_BUG_ON(!RB_EMPTY_NODE(&mo->it.rb));
> - interval_tree_insert(&mo->it, &mo->mn->objects);
> -}
> + struct drm_i915_gem_object *obj = container_of(mni, struct
> drm_i915_gem_object, userptr.notifier);
> + struct drm_i915_private *i915 = to_i915(obj->base.dev);
> + long r;
>
> -static void del_object(struct i915_mmu_object *mo)
> -{
> - if (RB_EMPTY_NODE(&mo->it.rb))
> - return;
> + if (!mmu_notifier_range_blockable(range))
> + return false;
>
> - interval_tree_remove(&mo->it, &mo->mn->objects);
> - RB_CLEAR_NODE(&mo->it.rb);
> -}
> + spin_lock(&i915->mm.notifier_lock);
>
> -static void
> -__i915_gem_userptr_set_active(struct drm_i915_gem_object *obj, bool value)
> -{
> - struct i915_mmu_object *mo = obj->userptr.mmu_object;
> + mmu_interval_set_seq(mni, cur_seq);
> +
> + spin_unlock(&i915->mm.notifier_lock);
>
> /*
> - * During mm_invalidate_range we need to cancel any userptr that
> - * overlaps the range being invalidated. Doing so requires the
> - * struct_mutex, and that risks recursion. In order to cause
> - * recursion, the user must alias the userptr address space with
> - * a GTT mmapping (possible with a MAP_FIXED) - then when we have
> - * to invalidate that mmaping, mm_invalidate_range is called with
> - * the userptr address *and* the struct_mutex held. To prevent that
> - * we set a flag under the i915_mmu_notifier spinlock to indicate
> - * whether this object is valid.
> + * We don't wait when the process is exiting. This is valid
> + * because the object will be cleaned up anyway.
> + *
> + * This is also temporarily required as a hack, because we
> + * cannot currently force non-consistent batch buffers to preempt
> + * and reschedule by waiting on it, hanging processes on exit.
> */
> - if (!mo)
> - return;
> -
> - spin_lock(&mo->mn->lock);
> - if (value)
> - add_object(mo);
> - else
> - del_object(mo);
> - spin_unlock(&mo->mn->lock);
> -}
> -
> -static int
> -userptr_mn_invalidate_range_start(struct mmu_notifier *_mn,
> - const struct mmu_notifier_range *range)
> -{
> - struct i915_mmu_notifier *mn =
> - container_of(_mn, struct i915_mmu_notifier, mn);
> - struct interval_tree_node *it;
> - unsigned long end;
> - int ret = 0;
> -
> - if (RB_EMPTY_ROOT(&mn->objects.rb_root))
> - return 0;
> -
> - /* interval ranges are inclusive, but invalidate range is exclusive */
> - end = range->end - 1;
> -
> - spin_lock(&mn->lock);
> - it = interval_tree_iter_first(&mn->objects, range->start, end);
> - while (it) {
> - struct drm_i915_gem_object *obj;
> -
> - if (!mmu_notifier_range_blockable(range)) {
> - ret = -EAGAIN;
> - break;
> - }
> -
> - /*
> - * The mmu_object is released late when destroying the
> - * GEM object so it is entirely possible to gain a
> - * reference on an object in the process of being freed
> - * since our serialisation is via the spinlock and not
> - * the struct_mutex - and consequently use it after it
> - * is freed and then double free it. To prevent that
> - * use-after-free we only acquire a reference on the
> - * object if it is not in the process of being destroyed.
> - */
> - obj = container_of(it, struct i915_mmu_object, it)->obj;
> - if (!kref_get_unless_zero(&obj->base.refcount)) {
> - it = interval_tree_iter_next(it, range->start, end);
> - continue;
> - }
> - spin_unlock(&mn->lock);
> -
> - ret = i915_gem_object_unbind(obj,
> - I915_GEM_OBJECT_UNBIND_ACTIVE |
> - I915_GEM_OBJECT_UNBIND_BARRIER);
> - if (ret == 0)
> - ret = __i915_gem_object_put_pages(obj);
> - i915_gem_object_put(obj);
> - if (ret)
> - return ret;
> + if (current->flags & PF_EXITING)
> + return true;
>
> - spin_lock(&mn->lock);
> -
> - /*
> - * As we do not (yet) protect the mmu from concurrent insertion
> - * over this range, there is no guarantee that this search will
> - * terminate given a pathologic workload.
> - */
> - it = interval_tree_iter_first(&mn->objects, range->start, end);
> - }
> - spin_unlock(&mn->lock);
> -
> - return ret;
> + /* we will unbind on next submission, still have userptr pins */
> + r = dma_resv_wait_timeout_rcu(obj->base.resv, true, false,
> + MAX_SCHEDULE_TIMEOUT);
> + if (r <= 0)
> + drm_err(&i915->drm, "(%ld) failed to wait for idle\n", r);
>
> + return true;
> }
>
> -static const struct mmu_notifier_ops i915_gem_userptr_notifier = {
> - .invalidate_range_start = userptr_mn_invalidate_range_start,
> +static const struct mmu_interval_notifier_ops i915_gem_userptr_notifier_ops
> = {
> + .invalidate = i915_gem_userptr_invalidate,
> };
>
> -static struct i915_mmu_notifier *
> -i915_mmu_notifier_create(struct i915_mm_struct *mm)
> -{
> - struct i915_mmu_notifier *mn;
> -
> - mn = kmalloc(sizeof(*mn), GFP_KERNEL);
> - if (mn == NULL)
> - return ERR_PTR(-ENOMEM);
> -
> - spin_lock_init(&mn->lock);
> - mn->mn.ops = &i915_gem_userptr_notifier;
> - mn->objects = RB_ROOT_CACHED;
> - mn->mm = mm;
> -
> - return mn;
> -}
> -
> -static void
> -i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj)
> -{
> - struct i915_mmu_object *mo;
> -
> - mo = fetch_and_zero(&obj->userptr.mmu_object);
> - if (!mo)
> - return;
> -
> - spin_lock(&mo->mn->lock);
> - del_object(mo);
> - spin_unlock(&mo->mn->lock);
> - kfree(mo);
> -}
> -
> -static struct i915_mmu_notifier *
> -i915_mmu_notifier_find(struct i915_mm_struct *mm)
> -{
> - struct i915_mmu_notifier *mn, *old;
> - int err;
> -
> - mn = READ_ONCE(mm->mn);
> - if (likely(mn))
> - return mn;
> -
> - mn = i915_mmu_notifier_create(mm);
> - if (IS_ERR(mn))
> - return mn;
> -
> - err = mmu_notifier_register(&mn->mn, mm->mm);
> - if (err) {
> - kfree(mn);
> - return ERR_PTR(err);
> - }
> -
> - old = cmpxchg(&mm->mn, NULL, mn);
> - if (old) {
> - mmu_notifier_unregister(&mn->mn, mm->mm);
> - kfree(mn);
> - mn = old;
> - }
> -
> - return mn;
> -}
> -
> static int
> i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj)
> {
> - struct i915_mmu_notifier *mn;
> - struct i915_mmu_object *mo;
> -
> - if (GEM_WARN_ON(!obj->userptr.mm))
> - return -EINVAL;
> -
> - mn = i915_mmu_notifier_find(obj->userptr.mm);
> - if (IS_ERR(mn))
> - return PTR_ERR(mn);
> -
> - mo = kzalloc(sizeof(*mo), GFP_KERNEL);
> - if (!mo)
> - return -ENOMEM;
> -
> - mo->mn = mn;
> - mo->obj = obj;
> - mo->it.start = obj->userptr.ptr;
> - mo->it.last = obj->userptr.ptr + obj->base.size - 1;
> - RB_CLEAR_NODE(&mo->it.rb);
> -
> - obj->userptr.mmu_object = mo;
> - return 0;
> -}
> -
> -static void
> -i915_mmu_notifier_free(struct i915_mmu_notifier *mn,
> - struct mm_struct *mm)
> -{
> - if (mn == NULL)
> - return;
> -
> - mmu_notifier_unregister(&mn->mn, mm);
> - kfree(mn);
> -}
> -
> -
> -static struct i915_mm_struct *
> -__i915_mm_struct_find(struct drm_i915_private *i915, struct mm_struct *real)
> -{
> - struct i915_mm_struct *it, *mm = NULL;
> -
> - rcu_read_lock();
> - hash_for_each_possible_rcu(i915->mm_structs,
> - it, node,
> - (unsigned long)real)
> - if (it->mm == real && kref_get_unless_zero(&it->kref)) {
> - mm = it;
> - break;
> - }
> - rcu_read_unlock();
> -
> - return mm;
> + return mmu_interval_notifier_insert(&obj->userptr.notifier, current->mm,
> + obj->userptr.ptr, obj->base.size,
> + &i915_gem_userptr_notifier_ops);
> }
>
> -static int
> -i915_gem_userptr_init__mm_struct(struct drm_i915_gem_object *obj)
> +static void i915_gem_object_userptr_drop_ref(struct drm_i915_gem_object *obj)
> {
> struct drm_i915_private *i915 = to_i915(obj->base.dev);
> - struct i915_mm_struct *mm, *new;
> - int ret = 0;
> -
> - /* During release of the GEM object we hold the struct_mutex. This
> - * precludes us from calling mmput() at that time as that may be
> - * the last reference and so call exit_mmap(). exit_mmap() will
> - * attempt to reap the vma, and if we were holding a GTT mmap
> - * would then call drm_gem_vm_close() and attempt to reacquire
> - * the struct mutex. So in order to avoid that recursion, we have
> - * to defer releasing the mm reference until after we drop the
> - * struct_mutex, i.e. we need to schedule a worker to do the clean
> - * up.
> - */
> - mm = __i915_mm_struct_find(i915, current->mm);
> - if (mm)
> - goto out;
> + struct page **pvec = NULL;
>
> - new = kmalloc(sizeof(*mm), GFP_KERNEL);
> - if (!new)
> - return -ENOMEM;
> -
> - kref_init(&new->kref);
> - new->i915 = to_i915(obj->base.dev);
> - new->mm = current->mm;
> - new->mn = NULL;
> -
> - spin_lock(&i915->mm_lock);
> - mm = __i915_mm_struct_find(i915, current->mm);
> - if (!mm) {
> - hash_add_rcu(i915->mm_structs,
> - &new->node,
> - (unsigned long)new->mm);
> - mmgrab(current->mm);
> - mm = new;
> + spin_lock(&i915->mm.notifier_lock);
> + if (!--obj->userptr.page_ref) {
> + pvec = obj->userptr.pvec;
> + obj->userptr.pvec = NULL;
> }
> - spin_unlock(&i915->mm_lock);
> - if (mm != new)
> - kfree(new);
> + GEM_BUG_ON(obj->userptr.page_ref < 0);
> + spin_unlock(&i915->mm.notifier_lock);
>
> -out:
> - obj->userptr.mm = mm;
> - return ret;
> -}
> -
> -static void
> -__i915_mm_struct_free__worker(struct work_struct *work)
> -{
> - struct i915_mm_struct *mm = container_of(work, typeof(*mm), work.work);
> -
> - i915_mmu_notifier_free(mm->mn, mm->mm);
> - mmdrop(mm->mm);
> - kfree(mm);
> -}
> -
> -static void
> -__i915_mm_struct_free(struct kref *kref)
> -{
> - struct i915_mm_struct *mm = container_of(kref, typeof(*mm), kref);
> -
> - spin_lock(&mm->i915->mm_lock);
> - hash_del_rcu(&mm->node);
> - spin_unlock(&mm->i915->mm_lock);
> -
> - INIT_RCU_WORK(&mm->work, __i915_mm_struct_free__worker);
> - queue_rcu_work(system_wq, &mm->work);
> -}
> -
> -static void
> -i915_gem_userptr_release__mm_struct(struct drm_i915_gem_object *obj)
> -{
> - if (obj->userptr.mm == NULL)
> - return;
> + if (pvec) {
> + const unsigned long num_pages = obj->base.size >> PAGE_SHIFT;
>
> - kref_put(&obj->userptr.mm->kref, __i915_mm_struct_free);
> - obj->userptr.mm = NULL;
> + unpin_user_pages(pvec, num_pages);
> + kfree(pvec);
This one needs to be kvfree apparently, per review from previous round.
Can you pls do a fixup patch? I'm already merging.
For the other pending review comments and suggestions I think it's better
if we handle this in a separate patch series to highlight all the
questions, and ideally with amdgpu folks involved too.
-Daniel
> + }
> }
>
> -struct get_pages_work {
> - struct work_struct work;
> - struct drm_i915_gem_object *obj;
> - struct task_struct *task;
> -};
> -
> -static struct sg_table *
> -__i915_gem_userptr_alloc_pages(struct drm_i915_gem_object *obj,
> - struct page **pvec, unsigned long num_pages)
> +static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
> {
> + struct drm_i915_private *i915 = to_i915(obj->base.dev);
> + const unsigned long num_pages = obj->base.size >> PAGE_SHIFT;
> unsigned int max_segment = i915_sg_segment_size();
> struct sg_table *st;
> unsigned int sg_page_sizes;
> struct scatterlist *sg;
> + struct page **pvec;
> int ret;
>
> st = kmalloc(sizeof(*st), GFP_KERNEL);
> if (!st)
> - return ERR_PTR(-ENOMEM);
> + return -ENOMEM;
> +
> + spin_lock(&i915->mm.notifier_lock);
> + if (GEM_WARN_ON(!obj->userptr.page_ref)) {
> + spin_unlock(&i915->mm.notifier_lock);
> + ret = -EFAULT;
> + goto err_free;
> + }
> +
> + obj->userptr.page_ref++;
> + pvec = obj->userptr.pvec;
> + spin_unlock(&i915->mm.notifier_lock);
>
> alloc_table:
> sg = __sg_alloc_table_from_pages(st, pvec, num_pages, 0,
> num_pages << PAGE_SHIFT, max_segment,
> NULL, 0, GFP_KERNEL);
> if (IS_ERR(sg)) {
> - kfree(st);
> - return ERR_CAST(sg);
> + ret = PTR_ERR(sg);
> + goto err;
> }
>
> ret = i915_gem_gtt_prepare_pages(obj, st);
> @@ -393,203 +170,20 @@ __i915_gem_userptr_alloc_pages(struct
> drm_i915_gem_object *obj,
> goto alloc_table;
> }
>
> - kfree(st);
> - return ERR_PTR(ret);
> + goto err;
> }
>
> sg_page_sizes = i915_sg_page_sizes(st->sgl);
>
> __i915_gem_object_set_pages(obj, st, sg_page_sizes);
>
> - return st;
> -}
> -
> -static void
> -__i915_gem_userptr_get_pages_worker(struct work_struct *_work)
> -{
> - struct get_pages_work *work = container_of(_work, typeof(*work), work);
> - struct drm_i915_gem_object *obj = work->obj;
> - const unsigned long npages = obj->base.size >> PAGE_SHIFT;
> - unsigned long pinned;
> - struct page **pvec;
> - int ret;
> -
> - ret = -ENOMEM;
> - pinned = 0;
> -
> - pvec = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
> - if (pvec != NULL) {
> - struct mm_struct *mm = obj->userptr.mm->mm;
> - unsigned int flags = 0;
> - int locked = 0;
> -
> - if (!i915_gem_object_is_readonly(obj))
> - flags |= FOLL_WRITE;
> -
> - ret = -EFAULT;
> - if (mmget_not_zero(mm)) {
> - while (pinned < npages) {
> - if (!locked) {
> - mmap_read_lock(mm);
> - locked = 1;
> - }
> - ret = pin_user_pages_remote
> - (mm,
> - obj->userptr.ptr + pinned * PAGE_SIZE,
> - npages - pinned,
> - flags,
> - pvec + pinned, NULL, &locked);
> - if (ret < 0)
> - break;
> -
> - pinned += ret;
> - }
> - if (locked)
> - mmap_read_unlock(mm);
> - mmput(mm);
> - }
> - }
> -
> - mutex_lock_nested(&obj->mm.lock, I915_MM_GET_PAGES);
> - if (obj->userptr.work == &work->work) {
> - struct sg_table *pages = ERR_PTR(ret);
> -
> - if (pinned == npages) {
> - pages = __i915_gem_userptr_alloc_pages(obj, pvec,
> - npages);
> - if (!IS_ERR(pages)) {
> - pinned = 0;
> - pages = NULL;
> - }
> - }
> -
> - obj->userptr.work = ERR_CAST(pages);
> - if (IS_ERR(pages))
> - __i915_gem_userptr_set_active(obj, false);
> - }
> - mutex_unlock(&obj->mm.lock);
> -
> - unpin_user_pages(pvec, pinned);
> - kvfree(pvec);
> -
> - i915_gem_object_put(obj);
> - put_task_struct(work->task);
> - kfree(work);
> -}
> -
> -static struct sg_table *
> -__i915_gem_userptr_get_pages_schedule(struct drm_i915_gem_object *obj)
> -{
> - struct get_pages_work *work;
> -
> - /* Spawn a worker so that we can acquire the
> - * user pages without holding our mutex. Access
> - * to the user pages requires mmap_lock, and we have
> - * a strict lock ordering of mmap_lock, struct_mutex -
> - * we already hold struct_mutex here and so cannot
> - * call gup without encountering a lock inversion.
> - *
> - * Userspace will keep on repeating the operation
> - * (thanks to EAGAIN) until either we hit the fast
> - * path or the worker completes. If the worker is
> - * cancelled or superseded, the task is still run
> - * but the results ignored. (This leads to
> - * complications that we may have a stray object
> - * refcount that we need to be wary of when
> - * checking for existing objects during creation.)
> - * If the worker encounters an error, it reports
> - * that error back to this function through
> - * obj->userptr.work = ERR_PTR.
> - */
> - work = kmalloc(sizeof(*work), GFP_KERNEL);
> - if (work == NULL)
> - return ERR_PTR(-ENOMEM);
> -
> - obj->userptr.work = &work->work;
> -
> - work->obj = i915_gem_object_get(obj);
> -
> - work->task = current;
> - get_task_struct(work->task);
> -
> - INIT_WORK(&work->work, __i915_gem_userptr_get_pages_worker);
> - queue_work(to_i915(obj->base.dev)->mm.userptr_wq, &work->work);
> -
> - return ERR_PTR(-EAGAIN);
> -}
> -
> -static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
> -{
> - const unsigned long num_pages = obj->base.size >> PAGE_SHIFT;
> - struct mm_struct *mm = obj->userptr.mm->mm;
> - struct page **pvec;
> - 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
> - * of rendering... Their loss. If they change the mapping of their
> - * pages they need to create a new bo to point to the new vma.
> - *
> - * However, that still leaves open the possibility of the vma
> - * being copied upon fork. Which falls under the same userspace
> - * synchronisation issue as a regular bo, except that this time
> - * the process may not be expecting that a particular piece of
> - * memory is tied to the GPU.
> - *
> - * Fortunately, we can hook into the mmu_notifier in order to
> - * discard the page references prior to anything nasty happening
> - * to the vma (discard or cloning) which should prevent the more
> - * egregious cases from causing harm.
> - */
> -
> - if (obj->userptr.work) {
> - /* active flag should still be held for the pending work */
> - if (IS_ERR(obj->userptr.work))
> - return PTR_ERR(obj->userptr.work);
> - else
> - return -EAGAIN;
> - }
> -
> - pvec = NULL;
> - pinned = 0;
> -
> - if (mm == current->mm) {
> - pvec = kvmalloc_array(num_pages, sizeof(struct page *),
> - GFP_KERNEL |
> - __GFP_NORETRY |
> - __GFP_NOWARN);
> - 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) {
> - pages = ERR_PTR(pinned);
> - pinned = 0;
> - } else if (pinned < num_pages) {
> - pages = __i915_gem_userptr_get_pages_schedule(obj);
> - active = pages == ERR_PTR(-EAGAIN);
> - } else {
> - pages = __i915_gem_userptr_alloc_pages(obj, pvec, num_pages);
> - active = !IS_ERR(pages);
> - }
> - if (active)
> - __i915_gem_userptr_set_active(obj, true);
> -
> - if (IS_ERR(pages))
> - unpin_user_pages(pvec, pinned);
> - kvfree(pvec);
> + return 0;
>
> - return PTR_ERR_OR_ZERO(pages);
> +err:
> + i915_gem_object_userptr_drop_ref(obj);
> +err_free:
> + kfree(st);
> + return ret;
> }
>
> static void
> @@ -599,9 +193,6 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object
> *obj,
> struct sgt_iter sgt_iter;
> struct page *page;
>
> - /* Cancel any inflight work and force them to restart their gup */
> - obj->userptr.work = NULL;
> - __i915_gem_userptr_set_active(obj, false);
> if (!pages)
> return;
>
> @@ -641,19 +232,161 @@ i915_gem_userptr_put_pages(struct drm_i915_gem_object
> *obj,
> }
>
> mark_page_accessed(page);
> - unpin_user_page(page);
> }
> obj->mm.dirty = false;
>
> sg_free_table(pages);
> kfree(pages);
> +
> + i915_gem_object_userptr_drop_ref(obj);
> +}
> +
> +static int i915_gem_object_userptr_unbind(struct drm_i915_gem_object *obj,
> bool get_pages)
> +{
> + struct sg_table *pages;
> + int err;
> +
> + err = i915_gem_object_unbind(obj, I915_GEM_OBJECT_UNBIND_ACTIVE);
> + if (err)
> + return err;
> +
> + if (GEM_WARN_ON(i915_gem_object_has_pinned_pages(obj)))
> + return -EBUSY;
> +
> + mutex_lock_nested(&obj->mm.lock, I915_MM_GET_PAGES);
> +
> + pages = __i915_gem_object_unset_pages(obj);
> + if (!IS_ERR_OR_NULL(pages))
> + i915_gem_userptr_put_pages(obj, pages);
> +
> + if (get_pages)
> + err = ____i915_gem_object_get_pages(obj);
> + mutex_unlock(&obj->mm.lock);
> +
> + return err;
> +}
> +
> +int i915_gem_object_userptr_submit_init(struct drm_i915_gem_object *obj)
> +{
> + struct drm_i915_private *i915 = to_i915(obj->base.dev);
> + const unsigned long num_pages = obj->base.size >> PAGE_SHIFT;
> + struct page **pvec;
> + unsigned int gup_flags = 0;
> + unsigned long notifier_seq;
> + int pinned, ret;
> +
> + if (obj->userptr.notifier.mm != current->mm)
> + return -EFAULT;
> +
> + ret = i915_gem_object_lock_interruptible(obj, NULL);
> + if (ret)
> + return ret;
> +
> + /* Make sure userptr is unbound for next attempt, so we don't use stale
> pages. */
> + ret = i915_gem_object_userptr_unbind(obj, false);
> + i915_gem_object_unlock(obj);
> + if (ret)
> + return ret;
> +
> + notifier_seq = mmu_interval_read_begin(&obj->userptr.notifier);
> +
> + pvec = kvmalloc_array(num_pages, sizeof(struct page *), GFP_KERNEL);
> + if (!pvec)
> + return -ENOMEM;
> +
> + if (!i915_gem_object_is_readonly(obj))
> + gup_flags |= FOLL_WRITE;
> +
> + pinned = ret = 0;
> + while (pinned < num_pages) {
> + ret = pin_user_pages_fast(obj->userptr.ptr + pinned * PAGE_SIZE,
> + num_pages - pinned, gup_flags,
> + &pvec[pinned]);
> + if (ret < 0)
> + goto out;
> +
> + pinned += ret;
> + }
> + ret = 0;
> +
> + spin_lock(&i915->mm.notifier_lock);
> +
> + if (mmu_interval_read_retry(&obj->userptr.notifier,
> + !obj->userptr.page_ref ? notifier_seq :
> + obj->userptr.notifier_seq)) {
> + ret = -EAGAIN;
> + goto out_unlock;
> + }
> +
> + if (!obj->userptr.page_ref++) {
> + obj->userptr.pvec = pvec;
> + obj->userptr.notifier_seq = notifier_seq;
> +
> + pvec = NULL;
> + }
> +
> +out_unlock:
> + spin_unlock(&i915->mm.notifier_lock);
> +
> +out:
> + if (pvec) {
> + unpin_user_pages(pvec, pinned);
> + kvfree(pvec);
> + }
> +
> + return ret;
> +}
> +
> +int i915_gem_object_userptr_submit_done(struct drm_i915_gem_object *obj)
> +{
> + if (mmu_interval_read_retry(&obj->userptr.notifier,
> + obj->userptr.notifier_seq)) {
> + /* We collided with the mmu notifier, need to retry */
> +
> + return -EAGAIN;
> + }
> +
> + return 0;
> +}
> +
> +void i915_gem_object_userptr_submit_fini(struct drm_i915_gem_object *obj)
> +{
> + i915_gem_object_userptr_drop_ref(obj);
> +}
> +
> +int i915_gem_object_userptr_validate(struct drm_i915_gem_object *obj)
> +{
> + int err;
> +
> + err = i915_gem_object_userptr_submit_init(obj);
> + if (err)
> + return err;
> +
> + err = i915_gem_object_lock_interruptible(obj, NULL);
> + if (!err) {
> + /*
> + * Since we only check validity, not use the pages,
> + * it doesn't matter if we collide with the mmu notifier,
> + * and -EAGAIN handling is not required.
> + */
> + err = i915_gem_object_pin_pages(obj);
> + if (!err)
> + i915_gem_object_unpin_pages(obj);
> +
> + i915_gem_object_unlock(obj);
> + }
> +
> + i915_gem_object_userptr_submit_fini(obj);
> + return err;
> }
>
> static void
> i915_gem_userptr_release(struct drm_i915_gem_object *obj)
> {
> - i915_gem_userptr_release__mmu_notifier(obj);
> - i915_gem_userptr_release__mm_struct(obj);
> + GEM_WARN_ON(obj->userptr.page_ref);
> +
> + mmu_interval_notifier_remove(&obj->userptr.notifier);
> + obj->userptr.notifier.mm = NULL;
> }
>
> static int
> @@ -686,7 +419,6 @@ static const struct drm_i915_gem_object_ops
> i915_gem_userptr_ops = {
> .name = "i915_gem_object_userptr",
> .flags = I915_GEM_OBJECT_IS_SHRINKABLE |
> I915_GEM_OBJECT_NO_MMAP |
> - I915_GEM_OBJECT_ASYNC_CANCEL |
> I915_GEM_OBJECT_IS_PROXY,
> .get_pages = i915_gem_userptr_get_pages,
> .put_pages = i915_gem_userptr_put_pages,
> @@ -793,6 +525,7 @@ i915_gem_userptr_ioctl(struct drm_device *dev,
> i915_gem_object_set_cache_coherency(obj, I915_CACHE_LLC);
>
> obj->userptr.ptr = args->user_ptr;
> + obj->userptr.notifier_seq = ULONG_MAX;
> if (args->flags & I915_USERPTR_READ_ONLY)
> i915_gem_object_set_readonly(obj);
>
> @@ -800,9 +533,7 @@ i915_gem_userptr_ioctl(struct drm_device *dev,
> * at binding. This means that we need to hook into the mmu_notifier
> * in order to detect if the mmu is destroyed.
> */
> - ret = i915_gem_userptr_init__mm_struct(obj);
> - if (ret == 0)
> - ret = i915_gem_userptr_init__mmu_notifier(obj);
> + ret = i915_gem_userptr_init__mmu_notifier(obj);
> if (ret == 0)
> ret = drm_gem_handle_create(file, &obj->base, &handle);
>
> @@ -821,15 +552,7 @@ i915_gem_userptr_ioctl(struct drm_device *dev,
> int i915_gem_init_userptr(struct drm_i915_private *dev_priv)
> {
> #ifdef CONFIG_MMU_NOTIFIER
> - spin_lock_init(&dev_priv->mm_lock);
> - hash_init(dev_priv->mm_structs);
> -
> - dev_priv->mm.userptr_wq =
> - alloc_workqueue("i915-userptr-acquire",
> - WQ_HIGHPRI | WQ_UNBOUND,
> - 0);
> - if (!dev_priv->mm.userptr_wq)
> - return -ENOMEM;
> + spin_lock_init(&dev_priv->mm.notifier_lock);
> #endif
>
> return 0;
> @@ -837,7 +560,4 @@ int i915_gem_init_userptr(struct drm_i915_private
> *dev_priv)
>
> void i915_gem_cleanup_userptr(struct drm_i915_private *dev_priv)
> {
> -#ifdef CONFIG_MMU_NOTIFIER
> - destroy_workqueue(dev_priv->mm.userptr_wq);
> -#endif
> }
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index d738e2ba07c8..7c16bd283b87 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -558,11 +558,10 @@ struct i915_gem_mm {
>
> #ifdef CONFIG_MMU_NOTIFIER
> /**
> - * Workqueue to fault in userptr pages, flushed by the execbuf
> - * when required but otherwise left to userspace to try again
> - * on EAGAIN.
> + * notifier_lock for mmu notifiers, memory may not be allocated
> + * while holding this lock.
> */
> - struct workqueue_struct *userptr_wq;
> + spinlock_t notifier_lock;
> #endif
>
> /* shrinker accounting, also useful for userland debugging */
> @@ -936,8 +935,6 @@ struct drm_i915_private {
> struct i915_ggtt ggtt; /* VM representing the global address space */
>
> struct i915_gem_mm mm;
> - DECLARE_HASHTABLE(mm_structs, 7);
> - spinlock_t mm_lock;
>
> /* Kernel Modesetting */
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index dde12ce4f90b..3dee4e31fb14 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -1067,10 +1067,8 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
> err_unlock:
> i915_gem_drain_workqueue(dev_priv);
>
> - if (ret != -EIO) {
> + if (ret != -EIO)
> intel_uc_cleanup_firmwares(&dev_priv->gt.uc);
> - i915_gem_cleanup_userptr(dev_priv);
> - }
>
> if (ret == -EIO) {
> /*
> @@ -1127,7 +1125,6 @@ void i915_gem_driver_release(struct drm_i915_private
> *dev_priv)
> intel_wa_list_free(&dev_priv->gt_wa_list);
>
> intel_uc_cleanup_firmwares(&dev_priv->gt.uc);
> - i915_gem_cleanup_userptr(dev_priv);
>
> i915_gem_drain_freed_objects(dev_priv);
>
> --
> 2.31.0
>
> _______________________________________________
> Intel-gfx mailing list
> intel-...@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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