linux_dsm_epyc7002/drivers/media/v4l2-core/videobuf2-dma-sg.c
Hans Verkuil 511a1b8a4c [media] Revert "[media] vb2: Push mmap_sem down to memops"
This reverts commit 48b25a3a71.

That commit caused two regressions. The first is a BUG:

Jun 14 18:42:15 test-media kernel: [  115.972299] BUG: unable to handle kernel NULL pointer dereference at 0000000000000100
Jun 14 18:42:15 test-media kernel: [  115.972307] IP: [<ffffffff810d5cd0>] __lock_acquire+0x2f0/0x2070
Jun 14 18:42:15 test-media kernel: [  115.972316] PGD 0
Jun 14 18:42:15 test-media kernel: [  115.972318] Oops: 0000 [#1] PREEMPT SMP
Jun 14 18:42:15 test-media kernel: [  115.972321] Modules linked in: vivid v4l2_dv_timings videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media vmw_balloon vmw_vmci acpi_cpufreq processor button
Jun 14 18:42:15 test-media kernel: [  115.972333] CPU: 0 PID: 1542 Comm: v4l2-ctl Not tainted 4.1.0-rc3-test-media #1190
Jun 14 18:42:15 test-media kernel: [  115.972336] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014
Jun 14 18:42:15 test-media kernel: [  115.972337] task: ffff880220ce4200 ti: ffff88021d16c000 task.ti: ffff88021d16c000
Jun 14 18:42:15 test-media kernel: [  115.972339] RIP: 0010:[<ffffffff810d5cd0>]  [<ffffffff810d5cd0>] __lock_acquire+0x2f0/0x2070
Jun 14 18:42:15 test-media kernel: [  115.972342] RSP: 0018:ffff88021d16f9b8  EFLAGS: 00010002
Jun 14 18:42:15 test-media kernel: [  115.972343] RAX: 0000000000000046 RBX: 0000000000000292 RCX: 0000000000000001
Jun 14 18:42:15 test-media kernel: [  115.972345] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000100
Jun 14 18:42:15 test-media kernel: [  115.972346] RBP: ffff88021d16fa88 R08: 0000000000000001 R09: 0000000000000000
Jun 14 18:42:15 test-media kernel: [  115.972347] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
Jun 14 18:42:15 test-media kernel: [  115.972348] R13: ffff880220ce4200 R14: 0000000000000100 R15: 0000000000000000
Jun 14 18:42:15 test-media kernel: [  115.972350] FS:  00007f2441e7f740(0000) GS:ffff880236e00000(0000) knlGS:0000000000000000
Jun 14 18:42:15 test-media kernel: [  115.972351] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
Jun 14 18:42:15 test-media kernel: [  115.972353] CR2: 0000000000000100 CR3: 0000000001e0b000 CR4: 00000000001406f0
Jun 14 18:42:15 test-media kernel: [  115.972424] Stack:
Jun 14 18:42:15 test-media kernel: [  115.972427]  ffff88021d16fa98 ffffffff810d6543 0000000000000006 0000000000000246
Jun 14 18:42:15 test-media kernel: [  115.972431]  ffff88021d16fa08 ffffffff810d532d ffff880220ce4a78 ffff880200000000
Jun 14 18:42:15 test-media kernel: [  115.972433]  ffff880200000001 0000000000000000 0000000000000001 000000000093a4a0
Jun 14 18:42:15 test-media kernel: [  115.972436] Call Trace:
Jun 14 18:42:15 test-media kernel: [  115.972440]  [<ffffffff810d6543>] ? __lock_acquire+0xb63/0x2070
Jun 14 18:42:15 test-media kernel: [  115.972443]  [<ffffffff810d532d>] ? mark_held_locks+0x6d/0xa0
Jun 14 18:42:15 test-media kernel: [  115.972445]  [<ffffffff810d37a8>] ? __lock_is_held+0x58/0x80
Jun 14 18:42:15 test-media kernel: [  115.972447]  [<ffffffff810d852c>] lock_acquire+0x6c/0xa0
Jun 14 18:42:15 test-media kernel: [  115.972452]  [<ffffffffa039f1f6>] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc]
Jun 14 18:42:15 test-media kernel: [  115.972458]  [<ffffffff819b1a92>] down_read+0x42/0x60
Jun 14 18:42:15 test-media kernel: [  115.972460]  [<ffffffffa039f1f6>] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc]
Jun 14 18:42:15 test-media kernel: [  115.972463]  [<ffffffff819af1b1>] ? mutex_lock_nested+0x2b1/0x560
Jun 14 18:42:15 test-media kernel: [  115.972467]  [<ffffffffa038fdc5>] ? vb2_queue_release+0x25/0x40 [videobuf2_core]
Jun 14 18:42:15 test-media kernel: [  115.972469]  [<ffffffffa039f1f6>] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc]
Jun 14 18:42:15 test-media kernel: [  115.972472]  [<ffffffffa038b626>] __vb2_queue_free+0x146/0x5e0 [videobuf2_core]
Jun 14 18:42:15 test-media kernel: [  115.972475]  [<ffffffffa038fdd3>] vb2_queue_release+0x33/0x40 [videobuf2_core]
Jun 14 18:42:15 test-media kernel: [  115.972478]  [<ffffffffa038fe75>] _vb2_fop_release+0x95/0xb0 [videobuf2_core]
Jun 14 18:42:15 test-media kernel: [  115.972481]  [<ffffffffa038feb9>] vb2_fop_release+0x29/0x50 [videobuf2_core]
Jun 14 18:42:15 test-media kernel: [  115.972485]  [<ffffffffa03ad372>] vivid_fop_release+0x92/0x230 [vivid]
Jun 14 18:42:15 test-media kernel: [  115.972491]  [<ffffffffa0358460>] v4l2_release+0x30/0x80 [videodev]
Jun 14 18:42:15 test-media kernel: [  115.972496]  [<ffffffff811a51d5>] __fput+0xe5/0x200
Jun 14 18:42:15 test-media kernel: [  115.972498]  [<ffffffff811a5339>] ____fput+0x9/0x10
Jun 14 18:42:15 test-media kernel: [  115.972501]  [<ffffffff810a9fa4>] task_work_run+0xc4/0xf0
Jun 14 18:42:15 test-media kernel: [  115.972504]  [<ffffffff8108c670>] do_exit+0x3a0/0xaf0
Jun 14 18:42:15 test-media kernel: [  115.972507]  [<ffffffff819b3a9b>] ? _raw_spin_unlock_irq+0x2b/0x60
Jun 14 18:42:15 test-media kernel: [  115.972509]  [<ffffffff8108e0ff>] do_group_exit+0x4f/0xe0
Jun 14 18:42:15 test-media kernel: [  115.972511]  [<ffffffff8109a170>] get_signal+0x200/0x8c0
Jun 14 18:42:15 test-media kernel: [  115.972514]  [<ffffffff819b14b5>] ? __mutex_unlock_slowpath+0xf5/0x240
Jun 14 18:42:15 test-media kernel: [  115.972518]  [<ffffffff81002593>] do_signal+0x23/0x820
Jun 14 18:42:15 test-media kernel: [  115.972521]  [<ffffffff819b1609>] ? mutex_unlock+0x9/0x10
Jun 14 18:42:15 test-media kernel: [  115.972524]  [<ffffffffa0358648>] ? v4l2_ioctl+0x78/0xf0 [videodev]
Jun 14 18:42:15 test-media kernel: [  115.972526]  [<ffffffff819b4653>] ? int_very_careful+0x5/0x46
Jun 14 18:42:15 test-media kernel: [  115.972529]  [<ffffffff810d54bd>] ? trace_hardirqs_on_caller+0x15d/0x200
Jun 14 18:42:15 test-media kernel: [  115.972531]  [<ffffffff81002de0>] do_notify_resume+0x50/0x60
Jun 14 18:42:15 test-media kernel: [  115.972533]  [<ffffffff819b46a6>] int_signal+0x12/0x17
Jun 14 18:42:15 test-media kernel: [  115.972534] Code: ca 81 31 c0 e8 7a e2 8c 00 e8 aa 1d 8d 00 0f 1f 44 00 00 31 db 48 81 c4 a8 00 00 00 89 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 66 90 <49> 81 3e 40 4e 02 82 b8 00 00 00 00 44 0f 44 e0 41 83 ff 01 0f
Jun 14 18:42:15 test-media kernel: [  115.972567] RIP  [<ffffffff810d5cd0>] __lock_acquire+0x2f0/0x2070
Jun 14 18:42:15 test-media kernel: [  115.972569]  RSP <ffff88021d16f9b8>
Jun 14 18:42:15 test-media kernel: [  115.972570] CR2: 0000000000000100
Jun 14 18:42:15 test-media kernel: [  115.972573] ---[ end trace 25595c2b8560cb57 ]---
Jun 14 18:42:15 test-media kernel: [  115.972575] Fixing recursive fault but reboot is needed!

This can be reproduced by loading the vivid driver and running:

v4l2-ctl --stream-user

and pressing Ctrl-C. You may have to try a few times, but in my experience this BUG
is triggered quite quickly.

The second is a possible deadlock:

Jun 14 18:44:07 test-media kernel: [   49.376650] ======================================================
Jun 14 18:44:07 test-media kernel: [   49.376651] [ INFO: possible circular locking dependency detected ]
Jun 14 18:44:07 test-media kernel: [   49.376653] 4.1.0-rc3-test-media #1190 Not tainted
Jun 14 18:44:07 test-media kernel: [   49.376654] -------------------------------------------------------
Jun 14 18:44:07 test-media kernel: [   49.376655] v4l2-compliance/1468 is trying to acquire lock:
Jun 14 18:44:07 test-media kernel: [   49.376657]  (&mm->mmap_sem){++++++}, at: [<ffffffffa03a81f6>] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc]
Jun 14 18:44:07 test-media kernel: [   49.376665]
Jun 14 18:44:07 test-media kernel: [   49.376665] but task is already holding lock:
Jun 14 18:44:07 test-media kernel: [   49.376666]  (&q->mmap_lock){+.+...}, at: [<ffffffffa0398dc5>] vb2_queue_release+0x25/0x40 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376670]
Jun 14 18:44:07 test-media kernel: [   49.376670] which lock already depends on the new lock.
Jun 14 18:44:07 test-media kernel: [   49.376670]
Jun 14 18:44:07 test-media kernel: [   49.376671]
Jun 14 18:44:07 test-media kernel: [   49.376671] the existing dependency chain (in reverse order) is:
Jun 14 18:44:07 test-media kernel: [   49.376672]
Jun 14 18:44:07 test-media kernel: [   49.376672] -> #1 (&q->mmap_lock){+.+...}:
Jun 14 18:44:07 test-media kernel: [   49.376675]        [<ffffffff810d852c>] lock_acquire+0x6c/0xa0
Jun 14 18:44:07 test-media kernel: [   49.376682]        [<ffffffff819aef5e>] mutex_lock_nested+0x5e/0x560
Jun 14 18:44:07 test-media kernel: [   49.376689]        [<ffffffffa03934a2>] vb2_mmap+0x232/0x350 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376691]        [<ffffffffa0395a60>] vb2_fop_mmap+0x20/0x30 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376694]        [<ffffffffa0361102>] v4l2_mmap+0x52/0x90 [videodev]
Jun 14 18:44:07 test-media kernel: [   49.376698]        [<ffffffff81177e33>] mmap_region+0x3b3/0x5e0
Jun 14 18:44:07 test-media kernel: [   49.376701]        [<ffffffff81178377>] do_mmap_pgoff+0x317/0x400
Jun 14 18:44:07 test-media kernel: [   49.376703]        [<ffffffff81165320>] vm_mmap_pgoff+0x90/0xc0
Jun 14 18:44:07 test-media kernel: [   49.376708]        [<ffffffff81176867>] SyS_mmap_pgoff+0x1d7/0x280
Jun 14 18:44:07 test-media kernel: [   49.376709]        [<ffffffff81007f8d>] SyS_mmap+0x1d/0x20
Jun 14 18:44:07 test-media kernel: [   49.376714]        [<ffffffff819b44ae>] system_call_fastpath+0x12/0x76
Jun 14 18:44:07 test-media kernel: [   49.376716]
Jun 14 18:44:07 test-media kernel: [   49.376716] -> #0 (&mm->mmap_sem){++++++}:
Jun 14 18:44:07 test-media kernel: [   49.376718]        [<ffffffff810d79b3>] __lock_acquire+0x1fd3/0x2070
Jun 14 18:44:07 test-media kernel: [   49.376720]        [<ffffffff810d852c>] lock_acquire+0x6c/0xa0
Jun 14 18:44:07 test-media kernel: [   49.376721]        [<ffffffff819b1a92>] down_read+0x42/0x60
Jun 14 18:44:07 test-media kernel: [   49.376723]        [<ffffffffa03a81f6>] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc]
Jun 14 18:44:07 test-media kernel: [   49.376725]        [<ffffffffa0394626>] __vb2_queue_free+0x146/0x5e0 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376727]        [<ffffffffa0398dd3>] vb2_queue_release+0x33/0x40 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376729]        [<ffffffffa0398e75>] _vb2_fop_release+0x95/0xb0 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376731]        [<ffffffffa0398eb9>] vb2_fop_release+0x29/0x50 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376733]        [<ffffffffa03b6372>] vivid_fop_release+0x92/0x230 [vivid]
Jun 14 18:44:07 test-media kernel: [   49.376737]        [<ffffffffa0361460>] v4l2_release+0x30/0x80 [videodev]
Jun 14 18:44:07 test-media kernel: [   49.376739]        [<ffffffff811a51d5>] __fput+0xe5/0x200
Jun 14 18:44:07 test-media kernel: [   49.376744]        [<ffffffff811a5339>] ____fput+0x9/0x10
Jun 14 18:44:07 test-media kernel: [   49.376746]        [<ffffffff810a9fa4>] task_work_run+0xc4/0xf0
Jun 14 18:44:07 test-media kernel: [   49.376749]        [<ffffffff81002dd1>] do_notify_resume+0x41/0x60
Jun 14 18:44:07 test-media kernel: [   49.376752]        [<ffffffff819b46a6>] int_signal+0x12/0x17
Jun 14 18:44:07 test-media kernel: [   49.376754]
Jun 14 18:44:07 test-media kernel: [   49.376754] other info that might help us debug this:
Jun 14 18:44:07 test-media kernel: [   49.376754]
Jun 14 18:44:07 test-media kernel: [   49.376755]  Possible unsafe locking scenario:
Jun 14 18:44:07 test-media kernel: [   49.376755]
Jun 14 18:44:07 test-media kernel: [   49.376756]        CPU0                    CPU1
Jun 14 18:44:07 test-media kernel: [   49.376757]        ----                    ----
Jun 14 18:44:07 test-media kernel: [   49.376758]   lock(&q->mmap_lock);
Jun 14 18:44:07 test-media kernel: [   49.376759]                                lock(&mm->mmap_sem);
Jun 14 18:44:07 test-media kernel: [   49.376760]                                lock(&q->mmap_lock);
Jun 14 18:44:07 test-media kernel: [   49.376761]   lock(&mm->mmap_sem);
Jun 14 18:44:07 test-media kernel: [   49.376763]
Jun 14 18:44:07 test-media kernel: [   49.376763]  *** DEADLOCK ***
Jun 14 18:44:07 test-media kernel: [   49.376763]
Jun 14 18:44:07 test-media kernel: [   49.376764] 2 locks held by v4l2-compliance/1468:
Jun 14 18:44:07 test-media kernel: [   49.376765]  #0:  (&dev->mutex#3){+.+.+.}, at: [<ffffffffa0398e0a>] _vb2_fop_release+0x2a/0xb0 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376770]  #1:  (&q->mmap_lock){+.+...}, at: [<ffffffffa0398dc5>] vb2_queue_release+0x25/0x40 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376773]
Jun 14 18:44:07 test-media kernel: [   49.376773] stack backtrace:
Jun 14 18:44:07 test-media kernel: [   49.376776] CPU: 2 PID: 1468 Comm: v4l2-compliance Not tainted 4.1.0-rc3-test-media #1190
Jun 14 18:44:07 test-media kernel: [   49.376777] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014
Jun 14 18:44:07 test-media kernel: [   49.376779]  ffffffff8279e0b0 ffff88021d6f7ba8 ffffffff819a7aac 0000000000000011
Jun 14 18:44:07 test-media kernel: [   49.376781]  ffffffff8279e0b0 ffff88021d6f7bf8 ffffffff819a3964 ffff88021d6f7bd8
Jun 14 18:44:07 test-media kernel: [   49.376783]  ffff8800ac8aa100 0000000000000002 ffff8800ac8aa9a0 0000000000000002
Jun 14 18:44:07 test-media kernel: [   49.376785] Call Trace:
Jun 14 18:44:07 test-media kernel: [   49.376788]  [<ffffffff819a7aac>] dump_stack+0x4f/0x7b
Jun 14 18:44:07 test-media kernel: [   49.376792]  [<ffffffff819a3964>] print_circular_bug+0x20f/0x251
Jun 14 18:44:07 test-media kernel: [   49.376793]  [<ffffffff810d79b3>] __lock_acquire+0x1fd3/0x2070
Jun 14 18:44:07 test-media kernel: [   49.376795]  [<ffffffff810d6543>] ? __lock_acquire+0xb63/0x2070
Jun 14 18:44:07 test-media kernel: [   49.376797]  [<ffffffff810d37a8>] ? __lock_is_held+0x58/0x80
Jun 14 18:44:07 test-media kernel: [   49.376798]  [<ffffffff810d852c>] lock_acquire+0x6c/0xa0
Jun 14 18:44:07 test-media kernel: [   49.376800]  [<ffffffffa03a81f6>] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc]
Jun 14 18:44:07 test-media kernel: [   49.376802]  [<ffffffff819b1a92>] down_read+0x42/0x60
Jun 14 18:44:07 test-media kernel: [   49.376803]  [<ffffffffa03a81f6>] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc]
Jun 14 18:44:07 test-media kernel: [   49.376805]  [<ffffffff819af1b1>] ? mutex_lock_nested+0x2b1/0x560
Jun 14 18:44:07 test-media kernel: [   49.376807]  [<ffffffffa0398dc5>] ? vb2_queue_release+0x25/0x40 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376808]  [<ffffffffa03a81f6>] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc]
Jun 14 18:44:07 test-media kernel: [   49.376810]  [<ffffffffa0398e0a>] ? _vb2_fop_release+0x2a/0xb0 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376812]  [<ffffffffa0394626>] __vb2_queue_free+0x146/0x5e0 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376814]  [<ffffffffa0398dd3>] vb2_queue_release+0x33/0x40 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376816]  [<ffffffffa0398e75>] _vb2_fop_release+0x95/0xb0 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376818]  [<ffffffffa0398eb9>] vb2_fop_release+0x29/0x50 [videobuf2_core]
Jun 14 18:44:07 test-media kernel: [   49.376820]  [<ffffffffa03b6372>] vivid_fop_release+0x92/0x230 [vivid]
Jun 14 18:44:07 test-media kernel: [   49.376822]  [<ffffffffa0361460>] v4l2_release+0x30/0x80 [videodev]
Jun 14 18:44:07 test-media kernel: [   49.376824]  [<ffffffff811a51d5>] __fput+0xe5/0x200
Jun 14 18:44:07 test-media kernel: [   49.376825]  [<ffffffff819b4653>] ? int_very_careful+0x5/0x46
Jun 14 18:44:07 test-media kernel: [   49.376827]  [<ffffffff811a5339>] ____fput+0x9/0x10
Jun 14 18:44:07 test-media kernel: [   49.376828]  [<ffffffff810a9fa4>] task_work_run+0xc4/0xf0
Jun 14 18:44:07 test-media kernel: [   49.376830]  [<ffffffff81002dd1>] do_notify_resume+0x41/0x60
Jun 14 18:44:07 test-media kernel: [   49.376832]  [<ffffffff819b46a6>] int_signal+0x12/0x17

This can be triggered by loading the vivid module with the module option 'no_error_inj=1'
and running 'v4l2-compliance -s5'. Again, it may take a few attempts to trigger this
but for me it happens quite quickly.

Without this patch I cannot reproduce these two issues. So reverting is the best
solution for now.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-06-18 14:34:22 -03:00

759 lines
18 KiB
C

/*
* videobuf2-dma-sg.c - dma scatter/gather memory allocator for videobuf2
*
* Copyright (C) 2010 Samsung Electronics
*
* Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <media/videobuf2-core.h>
#include <media/videobuf2-memops.h>
#include <media/videobuf2-dma-sg.h>
static int debug;
module_param(debug, int, 0644);
#define dprintk(level, fmt, arg...) \
do { \
if (debug >= level) \
printk(KERN_DEBUG "vb2-dma-sg: " fmt, ## arg); \
} while (0)
struct vb2_dma_sg_conf {
struct device *dev;
};
struct vb2_dma_sg_buf {
struct device *dev;
void *vaddr;
struct page **pages;
int offset;
enum dma_data_direction dma_dir;
struct sg_table sg_table;
/*
* This will point to sg_table when used with the MMAP or USERPTR
* memory model, and to the dma_buf sglist when used with the
* DMABUF memory model.
*/
struct sg_table *dma_sgt;
size_t size;
unsigned int num_pages;
atomic_t refcount;
struct vb2_vmarea_handler handler;
struct vm_area_struct *vma;
struct dma_buf_attachment *db_attach;
};
static void vb2_dma_sg_put(void *buf_priv);
static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
gfp_t gfp_flags)
{
unsigned int last_page = 0;
int size = buf->size;
while (size > 0) {
struct page *pages;
int order;
int i;
order = get_order(size);
/* Dont over allocate*/
if ((PAGE_SIZE << order) > size)
order--;
pages = NULL;
while (!pages) {
pages = alloc_pages(GFP_KERNEL | __GFP_ZERO |
__GFP_NOWARN | gfp_flags, order);
if (pages)
break;
if (order == 0) {
while (last_page--)
__free_page(buf->pages[last_page]);
return -ENOMEM;
}
order--;
}
split_page(pages, order);
for (i = 0; i < (1 << order); i++)
buf->pages[last_page++] = &pages[i];
size -= PAGE_SIZE << order;
}
return 0;
}
static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size,
enum dma_data_direction dma_dir, gfp_t gfp_flags)
{
struct vb2_dma_sg_conf *conf = alloc_ctx;
struct vb2_dma_sg_buf *buf;
struct sg_table *sgt;
int ret;
int num_pages;
DEFINE_DMA_ATTRS(attrs);
dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
if (WARN_ON(alloc_ctx == NULL))
return NULL;
buf = kzalloc(sizeof *buf, GFP_KERNEL);
if (!buf)
return NULL;
buf->vaddr = NULL;
buf->dma_dir = dma_dir;
buf->offset = 0;
buf->size = size;
/* size is already page aligned */
buf->num_pages = size >> PAGE_SHIFT;
buf->dma_sgt = &buf->sg_table;
buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
GFP_KERNEL);
if (!buf->pages)
goto fail_pages_array_alloc;
ret = vb2_dma_sg_alloc_compacted(buf, gfp_flags);
if (ret)
goto fail_pages_alloc;
ret = sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
buf->num_pages, 0, size, GFP_KERNEL);
if (ret)
goto fail_table_alloc;
/* Prevent the device from being released while the buffer is used */
buf->dev = get_device(conf->dev);
sgt = &buf->sg_table;
/*
* No need to sync to the device, this will happen later when the
* prepare() memop is called.
*/
sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
buf->dma_dir, &attrs);
if (!sgt->nents)
goto fail_map;
buf->handler.refcount = &buf->refcount;
buf->handler.put = vb2_dma_sg_put;
buf->handler.arg = buf;
atomic_inc(&buf->refcount);
dprintk(1, "%s: Allocated buffer of %d pages\n",
__func__, buf->num_pages);
return buf;
fail_map:
put_device(buf->dev);
sg_free_table(buf->dma_sgt);
fail_table_alloc:
num_pages = buf->num_pages;
while (num_pages--)
__free_page(buf->pages[num_pages]);
fail_pages_alloc:
kfree(buf->pages);
fail_pages_array_alloc:
kfree(buf);
return NULL;
}
static void vb2_dma_sg_put(void *buf_priv)
{
struct vb2_dma_sg_buf *buf = buf_priv;
struct sg_table *sgt = &buf->sg_table;
int i = buf->num_pages;
if (atomic_dec_and_test(&buf->refcount)) {
DEFINE_DMA_ATTRS(attrs);
dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
dprintk(1, "%s: Freeing buffer of %d pages\n", __func__,
buf->num_pages);
dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
buf->dma_dir, &attrs);
if (buf->vaddr)
vm_unmap_ram(buf->vaddr, buf->num_pages);
sg_free_table(buf->dma_sgt);
while (--i >= 0)
__free_page(buf->pages[i]);
kfree(buf->pages);
put_device(buf->dev);
kfree(buf);
}
}
static void vb2_dma_sg_prepare(void *buf_priv)
{
struct vb2_dma_sg_buf *buf = buf_priv;
struct sg_table *sgt = buf->dma_sgt;
/* DMABUF exporter will flush the cache for us */
if (buf->db_attach)
return;
dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
}
static void vb2_dma_sg_finish(void *buf_priv)
{
struct vb2_dma_sg_buf *buf = buf_priv;
struct sg_table *sgt = buf->dma_sgt;
/* DMABUF exporter will flush the cache for us */
if (buf->db_attach)
return;
dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
}
static inline int vma_is_io(struct vm_area_struct *vma)
{
return !!(vma->vm_flags & (VM_IO | VM_PFNMAP));
}
static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
unsigned long size,
enum dma_data_direction dma_dir)
{
struct vb2_dma_sg_conf *conf = alloc_ctx;
struct vb2_dma_sg_buf *buf;
unsigned long first, last;
int num_pages_from_user;
struct vm_area_struct *vma;
struct sg_table *sgt;
DEFINE_DMA_ATTRS(attrs);
dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
buf = kzalloc(sizeof *buf, GFP_KERNEL);
if (!buf)
return NULL;
buf->vaddr = NULL;
buf->dev = conf->dev;
buf->dma_dir = dma_dir;
buf->offset = vaddr & ~PAGE_MASK;
buf->size = size;
buf->dma_sgt = &buf->sg_table;
first = (vaddr & PAGE_MASK) >> PAGE_SHIFT;
last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
buf->num_pages = last - first + 1;
buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
GFP_KERNEL);
if (!buf->pages)
goto userptr_fail_alloc_pages;
vma = find_vma(current->mm, vaddr);
if (!vma) {
dprintk(1, "no vma for address %lu\n", vaddr);
goto userptr_fail_find_vma;
}
if (vma->vm_end < vaddr + size) {
dprintk(1, "vma at %lu is too small for %lu bytes\n",
vaddr, size);
goto userptr_fail_find_vma;
}
buf->vma = vb2_get_vma(vma);
if (!buf->vma) {
dprintk(1, "failed to copy vma\n");
goto userptr_fail_find_vma;
}
if (vma_is_io(buf->vma)) {
for (num_pages_from_user = 0;
num_pages_from_user < buf->num_pages;
++num_pages_from_user, vaddr += PAGE_SIZE) {
unsigned long pfn;
if (follow_pfn(vma, vaddr, &pfn)) {
dprintk(1, "no page for address %lu\n", vaddr);
break;
}
buf->pages[num_pages_from_user] = pfn_to_page(pfn);
}
} else
num_pages_from_user = get_user_pages(current, current->mm,
vaddr & PAGE_MASK,
buf->num_pages,
buf->dma_dir == DMA_FROM_DEVICE,
1, /* force */
buf->pages,
NULL);
if (num_pages_from_user != buf->num_pages)
goto userptr_fail_get_user_pages;
if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
buf->num_pages, buf->offset, size, 0))
goto userptr_fail_alloc_table_from_pages;
sgt = &buf->sg_table;
/*
* No need to sync to the device, this will happen later when the
* prepare() memop is called.
*/
sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
buf->dma_dir, &attrs);
if (!sgt->nents)
goto userptr_fail_map;
return buf;
userptr_fail_map:
sg_free_table(&buf->sg_table);
userptr_fail_alloc_table_from_pages:
userptr_fail_get_user_pages:
dprintk(1, "get_user_pages requested/got: %d/%d]\n",
buf->num_pages, num_pages_from_user);
if (!vma_is_io(buf->vma))
while (--num_pages_from_user >= 0)
put_page(buf->pages[num_pages_from_user]);
vb2_put_vma(buf->vma);
userptr_fail_find_vma:
kfree(buf->pages);
userptr_fail_alloc_pages:
kfree(buf);
return NULL;
}
/*
* @put_userptr: inform the allocator that a USERPTR buffer will no longer
* be used
*/
static void vb2_dma_sg_put_userptr(void *buf_priv)
{
struct vb2_dma_sg_buf *buf = buf_priv;
struct sg_table *sgt = &buf->sg_table;
int i = buf->num_pages;
DEFINE_DMA_ATTRS(attrs);
dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
dprintk(1, "%s: Releasing userspace buffer of %d pages\n",
__func__, buf->num_pages);
dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir,
&attrs);
if (buf->vaddr)
vm_unmap_ram(buf->vaddr, buf->num_pages);
sg_free_table(buf->dma_sgt);
while (--i >= 0) {
if (buf->dma_dir == DMA_FROM_DEVICE)
set_page_dirty_lock(buf->pages[i]);
if (!vma_is_io(buf->vma))
put_page(buf->pages[i]);
}
kfree(buf->pages);
vb2_put_vma(buf->vma);
kfree(buf);
}
static void *vb2_dma_sg_vaddr(void *buf_priv)
{
struct vb2_dma_sg_buf *buf = buf_priv;
BUG_ON(!buf);
if (!buf->vaddr) {
if (buf->db_attach)
buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf);
else
buf->vaddr = vm_map_ram(buf->pages,
buf->num_pages, -1, PAGE_KERNEL);
}
/* add offset in case userptr is not page-aligned */
return buf->vaddr ? buf->vaddr + buf->offset : NULL;
}
static unsigned int vb2_dma_sg_num_users(void *buf_priv)
{
struct vb2_dma_sg_buf *buf = buf_priv;
return atomic_read(&buf->refcount);
}
static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
{
struct vb2_dma_sg_buf *buf = buf_priv;
unsigned long uaddr = vma->vm_start;
unsigned long usize = vma->vm_end - vma->vm_start;
int i = 0;
if (!buf) {
printk(KERN_ERR "No memory to map\n");
return -EINVAL;
}
do {
int ret;
ret = vm_insert_page(vma, uaddr, buf->pages[i++]);
if (ret) {
printk(KERN_ERR "Remapping memory, error: %d\n", ret);
return ret;
}
uaddr += PAGE_SIZE;
usize -= PAGE_SIZE;
} while (usize > 0);
/*
* Use common vm_area operations to track buffer refcount.
*/
vma->vm_private_data = &buf->handler;
vma->vm_ops = &vb2_common_vm_ops;
vma->vm_ops->open(vma);
return 0;
}
/*********************************************/
/* DMABUF ops for exporters */
/*********************************************/
struct vb2_dma_sg_attachment {
struct sg_table sgt;
enum dma_data_direction dma_dir;
};
static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
struct dma_buf_attachment *dbuf_attach)
{
struct vb2_dma_sg_attachment *attach;
unsigned int i;
struct scatterlist *rd, *wr;
struct sg_table *sgt;
struct vb2_dma_sg_buf *buf = dbuf->priv;
int ret;
attach = kzalloc(sizeof(*attach), GFP_KERNEL);
if (!attach)
return -ENOMEM;
sgt = &attach->sgt;
/* Copy the buf->base_sgt scatter list to the attachment, as we can't
* map the same scatter list to multiple attachments at the same time.
*/
ret = sg_alloc_table(sgt, buf->dma_sgt->orig_nents, GFP_KERNEL);
if (ret) {
kfree(attach);
return -ENOMEM;
}
rd = buf->dma_sgt->sgl;
wr = sgt->sgl;
for (i = 0; i < sgt->orig_nents; ++i) {
sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
rd = sg_next(rd);
wr = sg_next(wr);
}
attach->dma_dir = DMA_NONE;
dbuf_attach->priv = attach;
return 0;
}
static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
struct dma_buf_attachment *db_attach)
{
struct vb2_dma_sg_attachment *attach = db_attach->priv;
struct sg_table *sgt;
if (!attach)
return;
sgt = &attach->sgt;
/* release the scatterlist cache */
if (attach->dma_dir != DMA_NONE)
dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
attach->dma_dir);
sg_free_table(sgt);
kfree(attach);
db_attach->priv = NULL;
}
static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
{
struct vb2_dma_sg_attachment *attach = db_attach->priv;
/* stealing dmabuf mutex to serialize map/unmap operations */
struct mutex *lock = &db_attach->dmabuf->lock;
struct sg_table *sgt;
mutex_lock(lock);
sgt = &attach->sgt;
/* return previously mapped sg table */
if (attach->dma_dir == dma_dir) {
mutex_unlock(lock);
return sgt;
}
/* release any previous cache */
if (attach->dma_dir != DMA_NONE) {
dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
attach->dma_dir);
attach->dma_dir = DMA_NONE;
}
/* mapping to the client with new direction */
sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
dma_dir);
if (!sgt->nents) {
pr_err("failed to map scatterlist\n");
mutex_unlock(lock);
return ERR_PTR(-EIO);
}
attach->dma_dir = dma_dir;
mutex_unlock(lock);
return sgt;
}
static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
struct sg_table *sgt, enum dma_data_direction dma_dir)
{
/* nothing to be done here */
}
static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf)
{
/* drop reference obtained in vb2_dma_sg_get_dmabuf */
vb2_dma_sg_put(dbuf->priv);
}
static void *vb2_dma_sg_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
{
struct vb2_dma_sg_buf *buf = dbuf->priv;
return buf->vaddr ? buf->vaddr + pgnum * PAGE_SIZE : NULL;
}
static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf)
{
struct vb2_dma_sg_buf *buf = dbuf->priv;
return vb2_dma_sg_vaddr(buf);
}
static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
struct vm_area_struct *vma)
{
return vb2_dma_sg_mmap(dbuf->priv, vma);
}
static struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
.attach = vb2_dma_sg_dmabuf_ops_attach,
.detach = vb2_dma_sg_dmabuf_ops_detach,
.map_dma_buf = vb2_dma_sg_dmabuf_ops_map,
.unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap,
.kmap = vb2_dma_sg_dmabuf_ops_kmap,
.kmap_atomic = vb2_dma_sg_dmabuf_ops_kmap,
.vmap = vb2_dma_sg_dmabuf_ops_vmap,
.mmap = vb2_dma_sg_dmabuf_ops_mmap,
.release = vb2_dma_sg_dmabuf_ops_release,
};
static struct dma_buf *vb2_dma_sg_get_dmabuf(void *buf_priv, unsigned long flags)
{
struct vb2_dma_sg_buf *buf = buf_priv;
struct dma_buf *dbuf;
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
exp_info.ops = &vb2_dma_sg_dmabuf_ops;
exp_info.size = buf->size;
exp_info.flags = flags;
exp_info.priv = buf;
if (WARN_ON(!buf->dma_sgt))
return NULL;
dbuf = dma_buf_export(&exp_info);
if (IS_ERR(dbuf))
return NULL;
/* dmabuf keeps reference to vb2 buffer */
atomic_inc(&buf->refcount);
return dbuf;
}
/*********************************************/
/* callbacks for DMABUF buffers */
/*********************************************/
static int vb2_dma_sg_map_dmabuf(void *mem_priv)
{
struct vb2_dma_sg_buf *buf = mem_priv;
struct sg_table *sgt;
if (WARN_ON(!buf->db_attach)) {
pr_err("trying to pin a non attached buffer\n");
return -EINVAL;
}
if (WARN_ON(buf->dma_sgt)) {
pr_err("dmabuf buffer is already pinned\n");
return 0;
}
/* get the associated scatterlist for this buffer */
sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);
if (IS_ERR(sgt)) {
pr_err("Error getting dmabuf scatterlist\n");
return -EINVAL;
}
buf->dma_sgt = sgt;
buf->vaddr = NULL;
return 0;
}
static void vb2_dma_sg_unmap_dmabuf(void *mem_priv)
{
struct vb2_dma_sg_buf *buf = mem_priv;
struct sg_table *sgt = buf->dma_sgt;
if (WARN_ON(!buf->db_attach)) {
pr_err("trying to unpin a not attached buffer\n");
return;
}
if (WARN_ON(!sgt)) {
pr_err("dmabuf buffer is already unpinned\n");
return;
}
if (buf->vaddr) {
dma_buf_vunmap(buf->db_attach->dmabuf, buf->vaddr);
buf->vaddr = NULL;
}
dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
buf->dma_sgt = NULL;
}
static void vb2_dma_sg_detach_dmabuf(void *mem_priv)
{
struct vb2_dma_sg_buf *buf = mem_priv;
/* if vb2 works correctly you should never detach mapped buffer */
if (WARN_ON(buf->dma_sgt))
vb2_dma_sg_unmap_dmabuf(buf);
/* detach this attachment */
dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach);
kfree(buf);
}
static void *vb2_dma_sg_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
unsigned long size, enum dma_data_direction dma_dir)
{
struct vb2_dma_sg_conf *conf = alloc_ctx;
struct vb2_dma_sg_buf *buf;
struct dma_buf_attachment *dba;
if (dbuf->size < size)
return ERR_PTR(-EFAULT);
buf = kzalloc(sizeof(*buf), GFP_KERNEL);
if (!buf)
return ERR_PTR(-ENOMEM);
buf->dev = conf->dev;
/* create attachment for the dmabuf with the user device */
dba = dma_buf_attach(dbuf, buf->dev);
if (IS_ERR(dba)) {
pr_err("failed to attach dmabuf\n");
kfree(buf);
return dba;
}
buf->dma_dir = dma_dir;
buf->size = size;
buf->db_attach = dba;
return buf;
}
static void *vb2_dma_sg_cookie(void *buf_priv)
{
struct vb2_dma_sg_buf *buf = buf_priv;
return buf->dma_sgt;
}
const struct vb2_mem_ops vb2_dma_sg_memops = {
.alloc = vb2_dma_sg_alloc,
.put = vb2_dma_sg_put,
.get_userptr = vb2_dma_sg_get_userptr,
.put_userptr = vb2_dma_sg_put_userptr,
.prepare = vb2_dma_sg_prepare,
.finish = vb2_dma_sg_finish,
.vaddr = vb2_dma_sg_vaddr,
.mmap = vb2_dma_sg_mmap,
.num_users = vb2_dma_sg_num_users,
.get_dmabuf = vb2_dma_sg_get_dmabuf,
.map_dmabuf = vb2_dma_sg_map_dmabuf,
.unmap_dmabuf = vb2_dma_sg_unmap_dmabuf,
.attach_dmabuf = vb2_dma_sg_attach_dmabuf,
.detach_dmabuf = vb2_dma_sg_detach_dmabuf,
.cookie = vb2_dma_sg_cookie,
};
EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);
void *vb2_dma_sg_init_ctx(struct device *dev)
{
struct vb2_dma_sg_conf *conf;
conf = kzalloc(sizeof(*conf), GFP_KERNEL);
if (!conf)
return ERR_PTR(-ENOMEM);
conf->dev = dev;
return conf;
}
EXPORT_SYMBOL_GPL(vb2_dma_sg_init_ctx);
void vb2_dma_sg_cleanup_ctx(void *alloc_ctx)
{
if (!IS_ERR_OR_NULL(alloc_ctx))
kfree(alloc_ctx);
}
EXPORT_SYMBOL_GPL(vb2_dma_sg_cleanup_ctx);
MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2");
MODULE_AUTHOR("Andrzej Pietrasiewicz");
MODULE_LICENSE("GPL");