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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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![Chris Wilson](/assets/img/avatar_default.png)
To silence the critcs: [56532.161115] workqueue: PF_MEMALLOC task 36(khugepaged) is flushing !WQ_MEM_RECLAIM i915-userptr-release: (null) [56532.161138] ------------[ cut here ]------------ [56532.161144] WARNING: CPU: 1 PID: 36 at kernel/workqueue.c:2418 check_flush_dependency+0xe8/0xf0 [56532.161145] Modules linked in: wmi_bmof [56532.161148] CPU: 1 PID: 36 Comm: khugepaged Not tainted 4.13.0-krejzi #1 [56532.161149] Hardware name: HP HP ProBook 470 G3/8102, BIOS N78 Ver. 01.17 06/08/2017 [56532.161150] task: ffff8802371ee200 task.stack: ffffc90000174000 [56532.161152] RIP: 0010:check_flush_dependency+0xe8/0xf0 [56532.161152] RSP: 0018:ffffc900001777b8 EFLAGS: 00010286 [56532.161153] RAX: 000000000000006c RBX: ffff88022fc5a000 RCX: 0000000000000001 [56532.161154] RDX: 0000000000000000 RSI: 0000000000000086 RDI: 00000000ffffffff [56532.161155] RBP: 0000000000000000 R08: 14f038bb55f6dae0 R09: 0000000000000516 [56532.161155] R10: ffffc900001778a0 R11: 000000006c756e28 R12: ffff8802371ee200 [56532.161156] R13: 0000000000000000 R14: 000000000000000b R15: ffffc90000177810 [56532.161157] FS: 0000000000000000(0000) GS:ffff880240480000(0000) knlGS:0000000000000000 [56532.161158] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [56532.161158] CR2: 0000000004795ff8 CR3: 000000000220a000 CR4: 00000000003406e0 [56532.161159] Call Trace: [56532.161161] ? flush_workqueue+0x136/0x3e0 [56532.161178] ? _raw_spin_unlock_irqrestore+0xf/0x30 [56532.161179] ? try_to_wake_up+0x1ce/0x3b0 [56532.161183] ? i915_gem_userptr_mn_invalidate_range_start+0x13f/0x150 [56532.161184] ? _raw_spin_unlock+0xd/0x20 [56532.161186] ? i915_gem_userptr_mn_invalidate_range_start+0x13f/0x150 [56532.161189] ? __mmu_notifier_invalidate_range_start+0x4a/0x70 [56532.161191] ? try_to_unmap_one+0x5e5/0x660 [56532.161193] ? rmap_walk_file+0xe4/0x240 [56532.161195] ? __ClearPageMovable+0x10/0x10 [56532.161196] ? try_to_unmap+0x8c/0xe0 [56532.161197] ? page_remove_rmap+0x280/0x280 [56532.161199] ? page_not_mapped+0x10/0x10 [56532.161200] ? page_get_anon_vma+0x90/0x90 [56532.161202] ? migrate_pages+0x6a5/0x940 [56532.161203] ? isolate_freepages_block+0x330/0x330 [56532.161205] ? compact_zone+0x593/0x6a0 [56532.161206] ? enqueue_task_fair+0xc3/0x1180 [56532.161208] ? compact_zone_order+0x9b/0xc0 [56532.161210] ? get_page_from_freelist+0x24a/0x900 [56532.161212] ? try_to_compact_pages+0xc8/0x240 [56532.161213] ? try_to_compact_pages+0xc8/0x240 [56532.161215] ? __alloc_pages_direct_compact+0x45/0xe0 [56532.161216] ? __alloc_pages_slowpath+0x845/0xb90 [56532.161218] ? __alloc_pages_nodemask+0x176/0x1f0 [56532.161220] ? wait_woken+0x80/0x80 [56532.161222] ? khugepaged+0x29e/0x17d0 [56532.161223] ? wait_woken+0x80/0x80 [56532.161225] ? collapse_shmem.isra.39+0xa60/0xa60 [56532.161226] ? kthread+0x10d/0x130 [56532.161227] ? kthread_create_on_node+0x60/0x60 [56532.161228] ? ret_from_fork+0x22/0x30 [56532.161229] Code: 00 8b b0 10 05 00 00 48 8d 8b b0 00 00 00 48 8d 90 b8 06 00 00 49 89 e8 48 c7 c7 38 55 09 82 c6 05 f9 c6 1d 01 01 e8 0e a1 03 00 <0f> ff e9 6b ff ff ff 90 48 8b 37 40 f6 c6 04 75 1b 48 c1 ee 05 [56532.161251] ---[ end trace 2ce2b4f5f69b803b ]--- Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20170911084135.22903-2-chris@chris-wilson.co.uk Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
828 lines
22 KiB
C
828 lines
22 KiB
C
/*
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* Copyright © 2012-2014 Intel Corporation
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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 "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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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 NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*
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*/
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#include <drm/drmP.h>
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#include <drm/i915_drm.h>
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#include "i915_drv.h"
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#include "i915_trace.h"
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#include "intel_drv.h"
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#include <linux/mmu_context.h>
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#include <linux/mmu_notifier.h>
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#include <linux/mempolicy.h>
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#include <linux/swap.h>
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#include <linux/sched/mm.h>
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struct i915_mm_struct {
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struct mm_struct *mm;
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struct drm_i915_private *i915;
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struct i915_mmu_notifier *mn;
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struct hlist_node node;
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struct kref kref;
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struct work_struct work;
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};
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#if defined(CONFIG_MMU_NOTIFIER)
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#include <linux/interval_tree.h>
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struct i915_mmu_notifier {
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spinlock_t lock;
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struct hlist_node node;
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struct mmu_notifier mn;
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struct rb_root objects;
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struct workqueue_struct *wq;
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};
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struct i915_mmu_object {
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struct i915_mmu_notifier *mn;
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struct drm_i915_gem_object *obj;
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struct interval_tree_node it;
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struct list_head link;
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struct work_struct work;
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bool attached;
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};
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static void cancel_userptr(struct work_struct *work)
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{
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struct i915_mmu_object *mo = container_of(work, typeof(*mo), work);
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struct drm_i915_gem_object *obj = mo->obj;
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struct work_struct *active;
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/* Cancel any active worker and force us to re-evaluate gup */
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mutex_lock(&obj->mm.lock);
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active = fetch_and_zero(&obj->userptr.work);
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mutex_unlock(&obj->mm.lock);
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if (active)
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goto out;
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i915_gem_object_wait(obj, I915_WAIT_ALL, MAX_SCHEDULE_TIMEOUT, NULL);
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mutex_lock(&obj->base.dev->struct_mutex);
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/* We are inside a kthread context and can't be interrupted */
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if (i915_gem_object_unbind(obj) == 0)
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__i915_gem_object_put_pages(obj, I915_MM_NORMAL);
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WARN_ONCE(obj->mm.pages,
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"Failed to release pages: bind_count=%d, pages_pin_count=%d, pin_display=%d\n",
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obj->bind_count,
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atomic_read(&obj->mm.pages_pin_count),
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obj->pin_display);
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mutex_unlock(&obj->base.dev->struct_mutex);
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out:
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i915_gem_object_put(obj);
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}
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static void add_object(struct i915_mmu_object *mo)
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{
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if (mo->attached)
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return;
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interval_tree_insert(&mo->it, &mo->mn->objects);
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mo->attached = true;
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}
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static void del_object(struct i915_mmu_object *mo)
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{
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if (!mo->attached)
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return;
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interval_tree_remove(&mo->it, &mo->mn->objects);
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mo->attached = false;
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}
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static void i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn,
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struct mm_struct *mm,
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unsigned long start,
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unsigned long end)
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{
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struct i915_mmu_notifier *mn =
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container_of(_mn, struct i915_mmu_notifier, mn);
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struct i915_mmu_object *mo;
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struct interval_tree_node *it;
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LIST_HEAD(cancelled);
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if (RB_EMPTY_ROOT(&mn->objects))
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return;
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/* interval ranges are inclusive, but invalidate range is exclusive */
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end--;
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spin_lock(&mn->lock);
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it = interval_tree_iter_first(&mn->objects, start, end);
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while (it) {
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/* The mmu_object is released late when destroying the
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* GEM object so it is entirely possible to gain a
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* reference on an object in the process of being freed
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* since our serialisation is via the spinlock and not
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* the struct_mutex - and consequently use it after it
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* is freed and then double free it. To prevent that
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* use-after-free we only acquire a reference on the
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* object if it is not in the process of being destroyed.
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*/
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mo = container_of(it, struct i915_mmu_object, it);
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if (kref_get_unless_zero(&mo->obj->base.refcount))
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queue_work(mn->wq, &mo->work);
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list_add(&mo->link, &cancelled);
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it = interval_tree_iter_next(it, start, end);
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}
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list_for_each_entry(mo, &cancelled, link)
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del_object(mo);
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spin_unlock(&mn->lock);
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if (!list_empty(&cancelled))
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flush_workqueue(mn->wq);
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}
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static const struct mmu_notifier_ops i915_gem_userptr_notifier = {
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.invalidate_range_start = i915_gem_userptr_mn_invalidate_range_start,
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};
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static struct i915_mmu_notifier *
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i915_mmu_notifier_create(struct mm_struct *mm)
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{
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struct i915_mmu_notifier *mn;
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int ret;
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mn = kmalloc(sizeof(*mn), GFP_KERNEL);
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if (mn == NULL)
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return ERR_PTR(-ENOMEM);
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spin_lock_init(&mn->lock);
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mn->mn.ops = &i915_gem_userptr_notifier;
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mn->objects = RB_ROOT;
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mn->wq = alloc_workqueue("i915-userptr-release", WQ_UNBOUND, 0);
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if (mn->wq == NULL) {
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kfree(mn);
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return ERR_PTR(-ENOMEM);
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}
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/* Protected by mmap_sem (write-lock) */
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ret = __mmu_notifier_register(&mn->mn, mm);
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if (ret) {
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destroy_workqueue(mn->wq);
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kfree(mn);
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return ERR_PTR(ret);
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}
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return mn;
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}
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static void
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i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj)
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{
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struct i915_mmu_object *mo;
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mo = obj->userptr.mmu_object;
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if (mo == NULL)
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return;
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spin_lock(&mo->mn->lock);
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del_object(mo);
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spin_unlock(&mo->mn->lock);
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kfree(mo);
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obj->userptr.mmu_object = NULL;
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}
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static struct i915_mmu_notifier *
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i915_mmu_notifier_find(struct i915_mm_struct *mm)
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{
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struct i915_mmu_notifier *mn = mm->mn;
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mn = mm->mn;
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if (mn)
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return mn;
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down_write(&mm->mm->mmap_sem);
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mutex_lock(&mm->i915->mm_lock);
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if ((mn = mm->mn) == NULL) {
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mn = i915_mmu_notifier_create(mm->mm);
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if (!IS_ERR(mn))
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mm->mn = mn;
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}
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mutex_unlock(&mm->i915->mm_lock);
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up_write(&mm->mm->mmap_sem);
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return mn;
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}
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static int
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i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj,
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unsigned flags)
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{
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struct i915_mmu_notifier *mn;
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struct i915_mmu_object *mo;
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if (flags & I915_USERPTR_UNSYNCHRONIZED)
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return capable(CAP_SYS_ADMIN) ? 0 : -EPERM;
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if (WARN_ON(obj->userptr.mm == NULL))
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return -EINVAL;
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mn = i915_mmu_notifier_find(obj->userptr.mm);
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if (IS_ERR(mn))
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return PTR_ERR(mn);
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mo = kzalloc(sizeof(*mo), GFP_KERNEL);
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if (mo == NULL)
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return -ENOMEM;
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mo->mn = mn;
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mo->obj = obj;
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mo->it.start = obj->userptr.ptr;
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mo->it.last = obj->userptr.ptr + obj->base.size - 1;
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INIT_WORK(&mo->work, cancel_userptr);
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obj->userptr.mmu_object = mo;
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return 0;
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}
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static void
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i915_mmu_notifier_free(struct i915_mmu_notifier *mn,
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struct mm_struct *mm)
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{
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if (mn == NULL)
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return;
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mmu_notifier_unregister(&mn->mn, mm);
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destroy_workqueue(mn->wq);
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kfree(mn);
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}
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#else
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static void
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i915_gem_userptr_release__mmu_notifier(struct drm_i915_gem_object *obj)
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{
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}
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static int
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i915_gem_userptr_init__mmu_notifier(struct drm_i915_gem_object *obj,
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unsigned flags)
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{
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if ((flags & I915_USERPTR_UNSYNCHRONIZED) == 0)
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return -ENODEV;
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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return 0;
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}
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static void
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i915_mmu_notifier_free(struct i915_mmu_notifier *mn,
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struct mm_struct *mm)
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{
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}
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#endif
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static struct i915_mm_struct *
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__i915_mm_struct_find(struct drm_i915_private *dev_priv, struct mm_struct *real)
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{
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struct i915_mm_struct *mm;
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/* Protected by dev_priv->mm_lock */
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hash_for_each_possible(dev_priv->mm_structs, mm, node, (unsigned long)real)
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if (mm->mm == real)
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return mm;
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return NULL;
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}
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static int
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i915_gem_userptr_init__mm_struct(struct drm_i915_gem_object *obj)
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{
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struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
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struct i915_mm_struct *mm;
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int ret = 0;
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/* During release of the GEM object we hold the struct_mutex. This
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* precludes us from calling mmput() at that time as that may be
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* the last reference and so call exit_mmap(). exit_mmap() will
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* attempt to reap the vma, and if we were holding a GTT mmap
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* would then call drm_gem_vm_close() and attempt to reacquire
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* the struct mutex. So in order to avoid that recursion, we have
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* to defer releasing the mm reference until after we drop the
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* struct_mutex, i.e. we need to schedule a worker to do the clean
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* up.
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*/
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mutex_lock(&dev_priv->mm_lock);
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mm = __i915_mm_struct_find(dev_priv, current->mm);
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if (mm == NULL) {
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mm = kmalloc(sizeof(*mm), GFP_KERNEL);
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if (mm == NULL) {
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ret = -ENOMEM;
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goto out;
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}
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kref_init(&mm->kref);
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mm->i915 = to_i915(obj->base.dev);
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mm->mm = current->mm;
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mmgrab(current->mm);
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mm->mn = NULL;
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/* Protected by dev_priv->mm_lock */
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hash_add(dev_priv->mm_structs,
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&mm->node, (unsigned long)mm->mm);
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} else
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kref_get(&mm->kref);
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obj->userptr.mm = mm;
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out:
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mutex_unlock(&dev_priv->mm_lock);
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return ret;
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}
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static void
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__i915_mm_struct_free__worker(struct work_struct *work)
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{
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struct i915_mm_struct *mm = container_of(work, typeof(*mm), work);
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i915_mmu_notifier_free(mm->mn, mm->mm);
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mmdrop(mm->mm);
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kfree(mm);
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}
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static void
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__i915_mm_struct_free(struct kref *kref)
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{
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struct i915_mm_struct *mm = container_of(kref, typeof(*mm), kref);
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/* Protected by dev_priv->mm_lock */
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hash_del(&mm->node);
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mutex_unlock(&mm->i915->mm_lock);
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INIT_WORK(&mm->work, __i915_mm_struct_free__worker);
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queue_work(mm->i915->mm.userptr_wq, &mm->work);
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}
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static void
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i915_gem_userptr_release__mm_struct(struct drm_i915_gem_object *obj)
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{
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if (obj->userptr.mm == NULL)
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return;
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kref_put_mutex(&obj->userptr.mm->kref,
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__i915_mm_struct_free,
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&to_i915(obj->base.dev)->mm_lock);
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obj->userptr.mm = NULL;
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}
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struct get_pages_work {
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struct work_struct work;
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struct drm_i915_gem_object *obj;
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struct task_struct *task;
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};
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|
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static struct sg_table *
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__i915_gem_userptr_alloc_pages(struct drm_i915_gem_object *obj,
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struct page **pvec, int num_pages)
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{
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unsigned int max_segment = i915_sg_segment_size();
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struct sg_table *st;
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int ret;
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|
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st = kmalloc(sizeof(*st), GFP_KERNEL);
|
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if (!st)
|
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return ERR_PTR(-ENOMEM);
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|
|
alloc_table:
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ret = __sg_alloc_table_from_pages(st, pvec, num_pages,
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0, num_pages << PAGE_SHIFT,
|
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max_segment,
|
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GFP_KERNEL);
|
|
if (ret) {
|
|
kfree(st);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
ret = i915_gem_gtt_prepare_pages(obj, st);
|
|
if (ret) {
|
|
sg_free_table(st);
|
|
|
|
if (max_segment > PAGE_SIZE) {
|
|
max_segment = PAGE_SIZE;
|
|
goto alloc_table;
|
|
}
|
|
|
|
kfree(st);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
return st;
|
|
}
|
|
|
|
static int
|
|
__i915_gem_userptr_set_active(struct drm_i915_gem_object *obj,
|
|
bool value)
|
|
{
|
|
int ret = 0;
|
|
|
|
/* 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.
|
|
*/
|
|
#if defined(CONFIG_MMU_NOTIFIER)
|
|
if (obj->userptr.mmu_object == NULL)
|
|
return 0;
|
|
|
|
spin_lock(&obj->userptr.mmu_object->mn->lock);
|
|
/* In order to serialise get_pages with an outstanding
|
|
* cancel_userptr, we must drop the struct_mutex and try again.
|
|
*/
|
|
if (!value)
|
|
del_object(obj->userptr.mmu_object);
|
|
else if (!work_pending(&obj->userptr.mmu_object->work))
|
|
add_object(obj->userptr.mmu_object);
|
|
else
|
|
ret = -EAGAIN;
|
|
spin_unlock(&obj->userptr.mmu_object->mn->lock);
|
|
#endif
|
|
|
|
return ret;
|
|
}
|
|
|
|
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 int npages = obj->base.size >> PAGE_SHIFT;
|
|
struct page **pvec;
|
|
int pinned, ret;
|
|
|
|
ret = -ENOMEM;
|
|
pinned = 0;
|
|
|
|
pvec = kvmalloc_array(npages, sizeof(struct page *), GFP_TEMPORARY);
|
|
if (pvec != NULL) {
|
|
struct mm_struct *mm = obj->userptr.mm->mm;
|
|
unsigned int flags = 0;
|
|
|
|
if (!obj->userptr.read_only)
|
|
flags |= FOLL_WRITE;
|
|
|
|
ret = -EFAULT;
|
|
if (mmget_not_zero(mm)) {
|
|
down_read(&mm->mmap_sem);
|
|
while (pinned < npages) {
|
|
ret = get_user_pages_remote
|
|
(work->task, mm,
|
|
obj->userptr.ptr + pinned * PAGE_SIZE,
|
|
npages - pinned,
|
|
flags,
|
|
pvec + pinned, NULL, NULL);
|
|
if (ret < 0)
|
|
break;
|
|
|
|
pinned += ret;
|
|
}
|
|
up_read(&mm->mmap_sem);
|
|
mmput(mm);
|
|
}
|
|
}
|
|
|
|
mutex_lock(&obj->mm.lock);
|
|
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)) {
|
|
__i915_gem_object_set_pages(obj, 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);
|
|
|
|
release_pages(pvec, pinned, 0);
|
|
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_sem, and we have
|
|
* a strict lock ordering of mmap_sem, 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 struct sg_table *
|
|
i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
|
|
{
|
|
const int 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;
|
|
|
|
/* 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 ERR_CAST(obj->userptr.work);
|
|
else
|
|
return ERR_PTR(-EAGAIN);
|
|
}
|
|
|
|
pvec = NULL;
|
|
pinned = 0;
|
|
|
|
if (mm == current->mm) {
|
|
pvec = kvmalloc_array(num_pages, sizeof(struct page *),
|
|
GFP_TEMPORARY |
|
|
__GFP_NORETRY |
|
|
__GFP_NOWARN);
|
|
if (pvec) /* defer to worker if malloc fails */
|
|
pinned = __get_user_pages_fast(obj->userptr.ptr,
|
|
num_pages,
|
|
!obj->userptr.read_only,
|
|
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))
|
|
release_pages(pvec, pinned, 0);
|
|
kvfree(pvec);
|
|
|
|
return pages;
|
|
}
|
|
|
|
static void
|
|
i915_gem_userptr_put_pages(struct drm_i915_gem_object *obj,
|
|
struct sg_table *pages)
|
|
{
|
|
struct sgt_iter sgt_iter;
|
|
struct page *page;
|
|
|
|
BUG_ON(obj->userptr.work != NULL);
|
|
__i915_gem_userptr_set_active(obj, false);
|
|
|
|
if (obj->mm.madv != I915_MADV_WILLNEED)
|
|
obj->mm.dirty = false;
|
|
|
|
i915_gem_gtt_finish_pages(obj, pages);
|
|
|
|
for_each_sgt_page(page, sgt_iter, pages) {
|
|
if (obj->mm.dirty)
|
|
set_page_dirty(page);
|
|
|
|
mark_page_accessed(page);
|
|
put_page(page);
|
|
}
|
|
obj->mm.dirty = false;
|
|
|
|
sg_free_table(pages);
|
|
kfree(pages);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
static int
|
|
i915_gem_userptr_dmabuf_export(struct drm_i915_gem_object *obj)
|
|
{
|
|
if (obj->userptr.mmu_object)
|
|
return 0;
|
|
|
|
return i915_gem_userptr_init__mmu_notifier(obj, 0);
|
|
}
|
|
|
|
static const struct drm_i915_gem_object_ops i915_gem_userptr_ops = {
|
|
.flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE |
|
|
I915_GEM_OBJECT_IS_SHRINKABLE,
|
|
.get_pages = i915_gem_userptr_get_pages,
|
|
.put_pages = i915_gem_userptr_put_pages,
|
|
.dmabuf_export = i915_gem_userptr_dmabuf_export,
|
|
.release = i915_gem_userptr_release,
|
|
};
|
|
|
|
/**
|
|
* Creates a new mm object that wraps some normal memory from the process
|
|
* context - user memory.
|
|
*
|
|
* We impose several restrictions upon the memory being mapped
|
|
* into the GPU.
|
|
* 1. It must be page aligned (both start/end addresses, i.e ptr and size).
|
|
* 2. It must be normal system memory, not a pointer into another map of IO
|
|
* space (e.g. it must not be a GTT mmapping of another object).
|
|
* 3. We only allow a bo as large as we could in theory map into the GTT,
|
|
* that is we limit the size to the total size of the GTT.
|
|
* 4. The bo is marked as being snoopable. The backing pages are left
|
|
* accessible directly by the CPU, but reads and writes by the GPU may
|
|
* incur the cost of a snoop (unless you have an LLC architecture).
|
|
*
|
|
* Synchronisation between multiple users and the GPU is left to userspace
|
|
* through the normal set-domain-ioctl. The kernel will enforce that the
|
|
* GPU relinquishes the VMA before it is returned back to the system
|
|
* i.e. upon free(), munmap() or process termination. However, the userspace
|
|
* malloc() library may not immediately relinquish the VMA after free() and
|
|
* instead reuse it whilst the GPU is still reading and writing to the VMA.
|
|
* Caveat emptor.
|
|
*
|
|
* Also note, that the object created here is not currently a "first class"
|
|
* object, in that several ioctls are banned. These are the CPU access
|
|
* ioctls: mmap(), pwrite and pread. In practice, you are expected to use
|
|
* direct access via your pointer rather than use those ioctls. Another
|
|
* restriction is that we do not allow userptr surfaces to be pinned to the
|
|
* hardware and so we reject any attempt to create a framebuffer out of a
|
|
* userptr.
|
|
*
|
|
* If you think this is a good interface to use to pass GPU memory between
|
|
* drivers, please use dma-buf instead. In fact, wherever possible use
|
|
* dma-buf instead.
|
|
*/
|
|
int
|
|
i915_gem_userptr_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
|
|
{
|
|
struct drm_i915_private *dev_priv = to_i915(dev);
|
|
struct drm_i915_gem_userptr *args = data;
|
|
struct drm_i915_gem_object *obj;
|
|
int ret;
|
|
u32 handle;
|
|
|
|
if (!HAS_LLC(dev_priv) && !HAS_SNOOP(dev_priv)) {
|
|
/* We cannot support coherent userptr objects on hw without
|
|
* LLC and broken snooping.
|
|
*/
|
|
return -ENODEV;
|
|
}
|
|
|
|
if (args->flags & ~(I915_USERPTR_READ_ONLY |
|
|
I915_USERPTR_UNSYNCHRONIZED))
|
|
return -EINVAL;
|
|
|
|
if (offset_in_page(args->user_ptr | args->user_size))
|
|
return -EINVAL;
|
|
|
|
if (!access_ok(args->flags & I915_USERPTR_READ_ONLY ? VERIFY_READ : VERIFY_WRITE,
|
|
(char __user *)(unsigned long)args->user_ptr, args->user_size))
|
|
return -EFAULT;
|
|
|
|
if (args->flags & I915_USERPTR_READ_ONLY) {
|
|
/* On almost all of the current hw, we cannot tell the GPU that a
|
|
* page is readonly, so this is just a placeholder in the uAPI.
|
|
*/
|
|
return -ENODEV;
|
|
}
|
|
|
|
obj = i915_gem_object_alloc(dev_priv);
|
|
if (obj == NULL)
|
|
return -ENOMEM;
|
|
|
|
drm_gem_private_object_init(dev, &obj->base, args->user_size);
|
|
i915_gem_object_init(obj, &i915_gem_userptr_ops);
|
|
obj->base.read_domains = I915_GEM_DOMAIN_CPU;
|
|
obj->base.write_domain = I915_GEM_DOMAIN_CPU;
|
|
i915_gem_object_set_cache_coherency(obj, I915_CACHE_LLC);
|
|
|
|
obj->userptr.ptr = args->user_ptr;
|
|
obj->userptr.read_only = !!(args->flags & I915_USERPTR_READ_ONLY);
|
|
|
|
/* And keep a pointer to the current->mm for resolving the user pages
|
|
* 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, args->flags);
|
|
if (ret == 0)
|
|
ret = drm_gem_handle_create(file, &obj->base, &handle);
|
|
|
|
/* drop reference from allocate - handle holds it now */
|
|
i915_gem_object_put(obj);
|
|
if (ret)
|
|
return ret;
|
|
|
|
args->handle = handle;
|
|
return 0;
|
|
}
|
|
|
|
int i915_gem_init_userptr(struct drm_i915_private *dev_priv)
|
|
{
|
|
mutex_init(&dev_priv->mm_lock);
|
|
hash_init(dev_priv->mm_structs);
|
|
|
|
dev_priv->mm.userptr_wq =
|
|
alloc_workqueue("i915-userptr-acquire",
|
|
WQ_HIGHPRI | WQ_MEM_RECLAIM,
|
|
0);
|
|
if (!dev_priv->mm.userptr_wq)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void i915_gem_cleanup_userptr(struct drm_i915_private *dev_priv)
|
|
{
|
|
destroy_workqueue(dev_priv->mm.userptr_wq);
|
|
}
|