Hi
this patch regresses buffer sharing between udl and amdgpu. The latter
uses TTM. When udl imports a dma_buf from amdgpu, vmap returns a kernel
address, but pagefaults on the buffer cannot be handled. A full error
message is attached. It fails right at [1], where udl read the first
pixel from the buffer. That pixel address is the vmap'ed buffer.
[1]
https://elixir.bootlin.com/linux/v6.15.5/source/drivers/gpu/drm/udl/udl_transfer.c#L109
Buffer sharing works with SHMEM-based drivers, which have their buffers
in system memory though. I assume that amdgpu's buffer is located in I/O
memory or scanout.
Best regards
Thomas
[ 168.785445] BUG: unable to handle page fault for address:
ffffc9012b800000
[ 168.792311] #PF: supervisor read access in kernel mode
[ 168.797452] #PF: error_code(0x0000) - not-present page
[ 168.802586] PGD 100000067 P4D 100000067 PUD 0
[ 168.807042] Oops: Oops: 0000 [#1] SMP KASAN PTI
[ 168.811573] CPU: 2 UID: 1000 PID: 2380 Comm: KMS thread Tainted:
G E 6.16.0-rc5-1-default+ #4080 PREEMPT(voluntary)
[ 168.823537] Tainted: [E]=UNSIGNED_MODULE
[ 168.827458] Hardware name: System manufacturer System Product
Name/Z170-A, BIOS 3802 03/15/2018
[ 168.836125] RIP: 0010:udl_compress_hline16+0x219/0x940 [udl]
[ 168.841779] Code: 0f b6 34 28 4c 89 d8 49 d3 e5 83 e0 07 4d 01 dd 83
f9 01 0f 84 4a 03 00 00 83 c0 03 40 38 f0 7c 09 40 84 f6 0f 85 82 05 00
00 <41> 8b 03 4c 63 7c 24 78 4c 89 5c 24 08 89 c6 41 89 c4 c1 e8 08
c1
[ 168.860476] RSP: 0018:ffff88811c7e75c0 EFLAGS: 00010246
[ 168.865697] RAX: 0000000000000003 RBX: 0000000000000000 RCX:
0000000000000002
[ 168.872815] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
0000000000000100
[ 168.879934] RBP: dffffc0000000000 R08: ffff8881082efe00 R09:
ffff8881082e0000
[ 168.887046] R10: 0000000000000002 R11: ffffc9012b800000 R12:
ffff88811c7e76f8
[ 168.894155] R13: ffffc9012b800400 R14: ffff8881082e0007 R15:
0000000000000000
[ 168.901266] FS: 00007f4685f3b6c0(0000) GS:ffff88846c690000(0000)
knlGS:0000000000000000
[ 168.909330] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 168.915058] CR2: ffffc9012b800000 CR3: 0000000117944004 CR4:
00000000003706f0
[ 168.922170] Call Trace:
[ 168.924616] <TASK>
[ 168.926714] ? validate_chain+0x24e/0x5e0
[ 168.930718] ? __lock_acquire+0x568/0xae0
[ 168.934725] udl_render_hline+0x165/0x33b [udl]
[ 168.939256] ? __pfx_udl_render_hline+0x10/0x10 [udl]
[ 168.944297] ? local_clock_noinstr+0xb/0x100
[ 168.948557] ? __lock_release.isra.0+0x16c/0x2e0
[ 168.953162] ? mark_held_locks+0x40/0x70
[ 168.957077] ? lockdep_hardirqs_on_prepare.part.0+0x92/0x170
[ 168.962721] udl_primary_plane_helper_atomic_update+0x432/0x670 [udl]
[ 168.969145] ? __pfx_udl_primary_plane_helper_atomic_update+0x10/0x10
[udl]
[ 168.976089] ? __pfx___drm_dev_dbg+0x10/0x10
[ 168.980357] ? drm_atomic_helper_calc_timestamping_constants+0x141/0x200
[ 168.987044] ? drm_atomic_helper_commit_planes+0x3b6/0x1030
[ 168.992599] drm_atomic_helper_commit_planes+0x3b6/0x1030
[ 168.997987] drm_atomic_helper_commit_tail+0x41/0xb0
[ 169.002943] commit_tail+0x204/0x330
[ 169.006513] drm_atomic_helper_commit+0x242/0x2e0
[ 169.011203] ? __pfx_drm_atomic_helper_commit+0x10/0x10
[ 169.016413] drm_atomic_commit+0x1e1/0x290
[ 169.020500] ? prepare_signaling+0x355/0xda0
[ 169.024769] ? __pfx_drm_atomic_commit+0x10/0x10
[ 169.029372] ? __pfx___drm_printfn_info+0x10/0x10
[ 169.034069] drm_mode_atomic_ioctl+0x8ff/0xe40
[ 169.038510] ? __pfx_drm_mode_atomic_ioctl+0x10/0x10
[ 169.043466] ? find_held_lock+0x2b/0x80
[ 169.047295] ? __lock_acquire+0x568/0xae0
[ 169.051293] ? mark_usage+0x65/0x180
[ 169.054870] ? __pfx_drm_mode_atomic_ioctl+0x10/0x10
[ 169.059823] ? do_raw_spin_unlock+0x55/0x230
[ 169.064081] ? drm_is_current_master+0x26/0x30
[ 169.068517] ? __pfx_drm_mode_atomic_ioctl+0x10/0x10
[ 169.073465] drm_ioctl_kernel+0x141/0x2b0
[ 169.077468] ? __pfx_drm_ioctl_kernel+0x10/0x10
[ 169.081987] ? lock_release.part.0+0x47/0x90
[ 169.086249] drm_ioctl+0x481/0xb50
[ 169.089653] ? __pfx_drm_mode_atomic_ioctl+0x10/0x10
[ 169.094610] ? __pfx_drm_ioctl+0x10/0x10
[ 169.098525] ? find_held_lock+0x2b/0x80
[ 169.102356] ? lock_release.part.0+0x47/0x90
[ 169.106621] ? __fget_files+0x1aa/0x2f0
[ 169.110450] ? __fget_files+0x1b4/0x2f0
[ 169.114281] __x64_sys_ioctl+0x135/0x1c0
[ 169.118201] do_syscall_64+0x68/0x2a0
[ 169.121856] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 169.126892] RIP: 0033:0x7f469391a53f
[ 169.130460] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10
00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f
05 <89> c2 3d 00 f0 ff ff 77 18 48 8b 44 24 18 64 48 2b 04 25 28 00
00
[ 169.149151] RSP: 002b:00007f4685f39a80 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
[ 169.156703] RAX: ffffffffffffffda RBX: 00007f465c002da0 RCX:
00007f469391a53f
[ 169.163868] RDX: 00007f4685f39b20 RSI: 00000000c03864bc RDI:
0000000000000010
[ 169.171029] RBP: 00007f4685f39b20 R08: 0000000000001310 R09:
00007f465c044cf0
[ 169.178194] R10: 0000000000000002 R11: 0000000000000246 R12:
00000000c03864bc
[ 169.185358] R13: 0000000000000010 R14: 00007f465c0284b0 R15:
00007f45d402b110
[ 169.192525] </TASK>
[ 169.194732] Modules linked in: udl(E) snd_seq_dummy(E) snd_hrtimer(E)
snd_seq(E) snd_seq_device(E) af_packet(E) nf_tables(E) iptable_filter(E)
binfmt_misc(E) intel_rapl_msr(E) nls_iso8859_1(E) eeepc_wmi(E) nls
_cp437(E) intel_rapl_common(E) snd_hda_codec_realtek(E) asus_wmi(E)
iTCO_wdt(E) vfat(E) ee1004(E) snd_hda_codec_generic(E) sparse_keymap(E)
x86_pkg_temp_thermal(E) iTCO_vendor_support(E) snd_hda_scodec_component(
E) intel_powerclamp(E) snd_hda_codec_hdmi(E) platform_profile(E) fat(E)
e1000e(E) i2c_i801(E) ptp(E) battery(E) snd_hda_intel(E) i2c_smbus(E)
snd_intel_dspcfg(E) mxm_wmi(E) rfkill(E) wmi_bmof(E) intel_wmi_thunder
bolt(E) coretemp(E) pps_core(E) i2c_mux(E) pcspkr(E) snd_hda_codec(E)
xfs(E) snd_hda_core(E) snd_hwdep(E) snd_pcm(E) snd_timer(E) snd(E)
soundcore(E) mei_me(E) acpi_pad(E) button(E) mei(E) joydev(E) nvme_fabrics(
E) loop(E) fuse(E) efi_pstore(E) dm_mod(E) configfs(E) nfnetlink(E)
ip_tables(E) x_tables(E) amdgpu(E) amdxcp(E) i2c_algo_bit(E)
drm_ttm_helper(E) ttm(E) drm_exec(E) hid_generic(E)
[ 169.194874] gpu_sched(E) drm_suballoc_helper(E)
ghash_clmulni_intel(E) sha512_ssse3(E) video(E) sha1_ssse3(E)
aesni_intel(E) usbhid(E) drm_panel_backlight_quirks(E) drm_buddy(E)
drm_display_helper(E) cec(E) w
mi(E) btrfs(E) blake2b_generic(E) xor(E) raid6_pq(E) msr(E) i2c_dev(E)
efivarfs(E) dmi_sysfs(E)
[ 169.311501] CR2: ffffc9012b800000
[ 169.314835] ---[ end trace 0000000000000000 ]---
[ 169.434549] RIP: 0010:udl_compress_hline16+0x219/0x940 [udl]
[ 169.440237] Code: 0f b6 34 28 4c 89 d8 49 d3 e5 83 e0 07 4d 01 dd 83
f9 01 0f 84 4a 03 00 00 83 c0 03 40 38 f0 7c 09 40 84 f6 0f 85 82 05 00
00 <41> 8b 03 4c 63 7c 24 78 4c 89 5c 24 08 89 c6 41 89 c4 c1 e8 08
c1
[ 169.459062] RSP: 0018:ffff88811c7e75c0 EFLAGS: 00010246
[ 169.464309] RAX: 0000000000000003 RBX: 0000000000000000 RCX:
0000000000000002
[ 169.471474] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
0000000000000100
[ 169.478635] RBP: dffffc0000000000 R08: ffff8881082efe00 R09:
ffff8881082e0000
[ 169.485800] R10: 0000000000000002 R11: ffffc9012b800000 R12:
ffff88811c7e76f8
[ 169.492962] R13: ffffc9012b800400 R14: ffff8881082e0007 R15:
0000000000000000
[ 169.500126] FS: 00007f4685f3b6c0(0000) GS:ffff88846c690000(0000)
knlGS:0000000000000000
[ 169.508246] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 169.514014] CR2: ffffc9012b800000 CR3: 0000000117944004 CR4:
00000000003706f0
[ 169.521180] note: KMS thread[2380] exited with irqs disabled
[ 175.343111]
==================================================================
[ 175.350342] BUG: KASAN: slab-use-after-free in
mutex_can_spin_on_owner+0x1a6/0x1c0
[ 175.357886] Read of size 4 at addr ffff8881172daff4 by task
kworker/5:0/49
[ 175.364738]
[ 175.366235] CPU: 5 UID: 0 PID: 49 Comm: kworker/5:0 Tainted: G
D E 6.16.0-rc5-1-default+ #4080 PREEMPT(voluntary)
[ 175.366240] Tainted: [D]=DIE, [E]=UNSIGNED_MODULE
[ 175.366242] Hardware name: System manufacturer System Product
Name/Z170-A, BIOS 3802 03/15/2018
[ 175.366244] Workqueue: events output_poll_execute
[ 175.366249] Call Trace:
[ 175.366251] <TASK>
[ 175.366254] dump_stack_lvl+0x68/0x90
[ 175.366259] ? mutex_can_spin_on_owner+0x1a6/0x1c0
[ 175.366261] print_address_description.constprop.0+0x88/0x380
[ 175.366266] ? lock_acquire+0xf2/0x140
[ 175.366269] ? mutex_can_spin_on_owner+0x1a6/0x1c0
[ 175.366272] print_report+0xf8/0x1e2
[ 175.366275] ? __virt_addr_valid+0x22e/0x500
[ 175.366279] ? kasan_addr_to_slab+0x9/0x90
[ 175.366282] ? mutex_can_spin_on_owner+0x1a6/0x1c0
[ 175.366284] kasan_report+0xd8/0x190
[ 175.366288] ? mutex_can_spin_on_owner+0x1a6/0x1c0
[ 175.366294] mutex_can_spin_on_owner+0x1a6/0x1c0
[ 175.366297] __ww_mutex_lock.constprop.0+0x2f8/0x34d0
[ 175.366301] ? do_raw_spin_trylock+0xa2/0x160
[ 175.366304] ? __pfx_do_raw_spin_trylock+0x10/0x10
[ 175.366308] ? get_nohz_timer_target+0x28/0x3d0
[ 175.366311] ? modeset_lock+0x3c6/0x640
[ 175.366316] ? __pfx___ww_mutex_lock.constprop.0+0x10/0x10
[ 175.366320] ? rcu_is_watching+0x11/0xb0
[ 175.366323] ? timerqueue_add+0x154/0x3c0
[ 175.366328] ? __hrtimer_start_range_ns+0x2e1/0x750
[ 175.366331] ? rcu_is_watching+0x11/0xb0
[ 175.366334] ? lock_acquired+0xb6/0xf0
[ 175.366337] ? rcu_is_watching+0x11/0xb0
[ 175.366340] ? rcu_is_watching+0x11/0xb0
[ 175.366342] ? drm_helper_probe_detect_ctx+0x6d/0x1a0
[ 175.366345] ? lock_acquire+0xf2/0x140
[ 175.366349] ? ww_mutex_lock+0x27/0x150
[ 175.366352] ? drm_helper_probe_detect_ctx+0x6d/0x1a0
[ 175.366355] ww_mutex_lock+0x27/0x150
[ 175.366358] modeset_lock+0x3c6/0x640
[ 175.366362] drm_helper_probe_detect_ctx+0xa6/0x1a0
[ 175.366366] ? __pfx_drm_helper_probe_detect_ctx+0x10/0x10
[ 175.366375] ? __pfx_drm_connector_list_iter_next+0x10/0x10
[ 175.366381] output_poll_execute+0x29b/0x760
[ 175.366387] ? trace_hardirqs_on+0x14/0x150
[ 175.366391] ? __pfx_output_poll_execute+0x10/0x10
[ 175.366396] process_one_work+0x7b5/0x1390
[ 175.366404] ? __pfx_process_one_work+0x10/0x10
[ 175.366409] ? assign_work+0x156/0x390
[ 175.366413] worker_thread+0x58d/0xf60
[ 175.366420] ? __pfx_worker_thread+0x10/0x10
[ 175.366422] kthread+0x370/0x720
[ 175.366425] ? __pfx_kthread+0x10/0x10
[ 175.366428] ? local_clock_noinstr+0x56/0x100
[ 175.366431] ? local_clock+0x11/0x30
[ 175.366433] ? __lock_release.isra.0+0x16c/0x2e0
[ 175.366437] ? rcu_is_watching+0x11/0xb0
[ 175.366439] ? lockdep_hardirqs_on_prepare.part.0+0x92/0x170
[ 175.366442] ? __pfx_kthread+0x10/0x10
[ 175.366445] ret_from_fork+0x1f4/0x2f0
[ 175.366448] ? __pfx_kthread+0x10/0x10
[ 175.366450] ret_from_fork_asm+0x1a/0x30
[ 175.366459] </TASK>
[ 175.366460]
[ 175.632772] Allocated by task 2342:
[ 175.636282] kasan_save_stack+0x1c/0x40
[ 175.640137] kasan_save_track+0x10/0x30
[ 175.643992] __kasan_slab_alloc+0x5f/0x70
[ 175.648023] kmem_cache_alloc_node_noprof+0x13a/0x380
[ 175.653097] dup_task_struct+0x32/0x730
[ 175.656952] copy_process+0x2d8/0x5380
[ 175.660720] kernel_clone+0x9f/0x5e0
[ 175.664318] __do_sys_clone3+0x135/0x180
[ 175.668258] do_syscall_64+0x68/0x2a0
[ 175.671940] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 175.677014]
[ 175.678520] Freed by task 0:
[ 175.681418] kasan_save_stack+0x1c/0x40
[ 175.685273] kasan_save_track+0x10/0x30
[ 175.689130] kasan_save_free_info+0x37/0x70
[ 175.693333] __kasan_slab_free+0x33/0x40
[ 175.697278] kmem_cache_free+0x10b/0x4d0
[ 175.701221] delayed_put_task_struct+0x15e/0x1e0
[ 175.705858] rcu_do_batch+0x2e3/0xb30
[ 175.709542] rcu_core+0x51d/0xb60
[ 175.712873] handle_softirqs+0x1a2/0x6b0
[ 175.716817] __irq_exit_rcu+0xf7/0x160
[ 175.720585] irq_exit_rcu+0xa/0x30
[ 175.724006] sysvec_apic_timer_interrupt+0x9d/0xc0
[ 175.728820] asm_sysvec_apic_timer_interrupt+0x16/0x20
[ 175.733980]
[ 175.735486] Last potentially related work creation:
[ 175.740385] kasan_save_stack+0x1c/0x40
[ 175.744243] kasan_record_aux_stack+0x88/0xa0
[ 175.748618] __call_rcu_common.constprop.0+0x77/0x850
[ 175.753693] __schedule+0x887/0x1d00
[ 175.757287] schedule+0xd0/0x260
[ 175.760533] smpboot_thread_fn+0x583/0x7a0
[ 175.764650] kthread+0x370/0x720
[ 175.767896] ret_from_fork+0x1f4/0x2f0
[ 175.771665] ret_from_fork_asm+0x1a/0x30
[ 175.775608]
[ 175.777113] Second to last potentially related work creation:
[ 175.782886] kasan_save_stack+0x1c/0x40
[ 175.786739] kasan_record_aux_stack+0x88/0xa0
[ 175.791118] task_work_add+0x1b1/0x270
[ 175.794886] sched_tick+0x226/0x6f0
[ 175.798394] update_process_times+0xe9/0x1f0
[ 175.802685] tick_nohz_handler+0x1a6/0x4b0
[ 175.806801] __hrtimer_run_queues+0x161/0x960
[ 175.811181] hrtimer_interrupt+0x33e/0x880
[ 175.815295] __sysvec_apic_timer_interrupt+0xf6/0x390
[ 175.820370] sysvec_apic_timer_interrupt+0x98/0xc0
[ 175.825183] asm_sysvec_apic_timer_interrupt+0x16/0x20
[ 175.830343]
[ 175.831849] The buggy address belongs to the object at ffff8881172dafc0
[ 175.831849] which belongs to the cache task_struct of size 11968
[ 175.844582] The buggy address is located 52 bytes inside of
[ 175.844582] freed 11968-byte region [ffff8881172dafc0, ffff8881172dde80)
[ 175.856969]
[ 175.858474] The buggy address belongs to the physical page:
[ 175.864070] page: refcount:0 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x1172d8
[ 175.872104] head: order:3 mapcount:0 entire_mapcount:0
nr_pages_mapped:0 pincount:0
[ 175.879788] memcg:ffff88811068a301
[ 175.883209] anon flags:
0x2ffff800000040(head|node=0|zone=2|lastcpupid=0x1ffff)
[ 175.890547] page_type: f5(slab)
[ 175.893706] raw: 002ffff800000040 ffff888100930500 0000000000000000
0000000000000001
[ 175.901479] raw: 0000000000000000 0000000000020002 00000000f5000000
ffff88811068a301
[ 175.909249] head: 002ffff800000040 ffff888100930500 0000000000000000
0000000000000001
[ 175.917109] head: 0000000000000000 0000000000020002 00000000f5000000
ffff88811068a301
[ 175.924968] head: 002ffff800000003 ffffea00045cb601 00000000ffffffff
00000000ffffffff
[ 175.932827] head: ffffffffffffffff 0000000000000000 00000000ffffffff
0000000000000008
[ 175.940685] page dumped because: kasan: bad access detected
[ 175.946283]
[ 175.947787] Memory state around the buggy address:
[ 175.952603] ffff8881172dae80: fb fb fb fb fb fb fb fb fc fc fc fc fc
fc fc fc
[ 175.959854] ffff8881172daf00: fc fc fc fc fc fc fc fc fc fc fc fc fc
fc fc fc
[ 175.967101] >ffff8881172daf80: fc fc fc fc fc fc fc fc fa fb fb fb fb
fb fb fb
[ 175.974353] ^
[ 175.981256] ffff8881172db000: fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb
[ 175.988504] ffff8881172db080: fb fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb
[ 175.995755]
==================================================================
Am 22.05.25 um 09:07 schrieb oushixiong1...@163.com:
From: Shixiong Ou <oushixi...@kylinos.cn>
[WHY]
1. Drivers using DRM_GEM_SHADOW_PLANE_HELPER_FUNCS and
DRM_GEM_SHMEM_DRIVER_OPS (e.g., udl, ast) do not require
sg_table import.
They only need dma_buf_vmap() to access the shared buffer's
kernel virtual address.
2. On certain Aspeed-based boards, a dma_mask of 0xffff_ffff may
trigger SWIOTLB during dmabuf import. However, IO_TLB_SEGSIZE
restricts the maximum DMA streaming mapping memory, resulting in
errors like:
ast 0000:07:00.0: swiotlb buffer is full (sz: 3145728 bytes), total 32768
(slots), used 0 (slots)
[HOW]
Provide a gem_prime_import implementation without sg_table mapping
to avoid issues (e.g., "swiotlb buffer is full"). Drivers that do not
require sg_table can adopt this.
Signed-off-by: Shixiong Ou <oushixi...@kylinos.cn>
---
v1->v2:
Patch rebase.
v2->v3:
Rename the import callback function.
Remove drm_gem_shmem_prime_export() and separate some codes
to drm_gem_prime_import_self().
v3->v4:
Separate the test from the policy.
Rename the macro.
v4->v5:
Rename some functions.
drivers/gpu/drm/drm_gem_shmem_helper.c | 57 ++++++++++++++++++++++++++
drivers/gpu/drm/drm_prime.c | 36 ++++++++++++----
include/drm/drm_gem_shmem_helper.h | 15 +++++++
include/drm/drm_prime.h | 3 ++
4 files changed, 102 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c
b/drivers/gpu/drm/drm_gem_shmem_helper.c
index aa43265f4f4f..126aa79042ad 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -800,6 +800,63 @@ drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
}
EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table);
+/**
+ * drm_gem_shmem_prime_import_no_map - Import dmabuf without mapping its
sg_table
+ * @dev: Device to import into
+ * @dma_buf: dma-buf object to import
+ *
+ * Drivers that use the shmem helpers but also wants to import dmabuf without
+ * mapping its sg_table can use this as their &drm_driver.gem_prime_import
+ * implementation.
+ */
+struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device
*dev,
+ struct dma_buf
*dma_buf)
+{
+ struct dma_buf_attachment *attach;
+ struct drm_gem_shmem_object *shmem;
+ struct drm_gem_object *obj;
+ size_t size;
+ int ret;
+
+ if (drm_gem_is_prime_exported_dma_buf(dev, dma_buf)) {
+ /*
+ * Importing dmabuf exported from our own gem increases
+ * refcount on gem itself instead of f_count of dmabuf.
+ */
+ obj = dma_buf->priv;
+ drm_gem_object_get(obj);
+ return obj;
+ }
+
+ attach = dma_buf_attach(dma_buf, dev->dev);
+ if (IS_ERR(attach))
+ return ERR_CAST(attach);
+
+ get_dma_buf(dma_buf);
+
+ size = PAGE_ALIGN(attach->dmabuf->size);
+
+ shmem = __drm_gem_shmem_create(dev, size, true, NULL);
+ if (IS_ERR(shmem)) {
+ ret = PTR_ERR(shmem);
+ goto fail_detach;
+ }
+
+ drm_dbg_prime(dev, "size = %zu\n", size);
+
+ shmem->base.import_attach = attach;
+ shmem->base.resv = dma_buf->resv;
+
+ return &shmem->base;
+
+fail_detach:
+ dma_buf_detach(dma_buf, attach);
+ dma_buf_put(dma_buf);
+
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_no_map);
+
MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
MODULE_IMPORT_NS("DMA_BUF");
MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index d828502268b8..b825b71038d6 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -910,6 +910,26 @@ struct dma_buf *drm_gem_prime_export(struct drm_gem_object
*obj,
}
EXPORT_SYMBOL(drm_gem_prime_export);
+
+/**
+ * drm_gem_is_prime_exported_dma_buf -
+ * checks if the DMA-BUF was exported from a GEM object belonging to @dev.
+ * @dev: drm_device to check against
+ * @dma_buf: dma-buf object to import
+ *
+ * Return: true if the DMA-BUF was exported from a GEM object belonging
+ * to @dev, false otherwise.
+ */
+
+bool drm_gem_is_prime_exported_dma_buf(struct drm_device *dev,
+ struct dma_buf *dma_buf)
+{
+ struct drm_gem_object *obj = dma_buf->priv;
+
+ return (dma_buf->ops == &drm_gem_prime_dmabuf_ops) && (obj->dev == dev);
+}
+EXPORT_SYMBOL(drm_gem_is_prime_exported_dma_buf);
+
/**
* drm_gem_prime_import_dev - core implementation of the import callback
* @dev: drm_device to import into
@@ -933,16 +953,14 @@ struct drm_gem_object *drm_gem_prime_import_dev(struct
drm_device *dev,
struct drm_gem_object *obj;
int ret;
- if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) {
+ if (drm_gem_is_prime_exported_dma_buf(dev, dma_buf)) {
+ /*
+ * Importing dmabuf exported from our own gem increases
+ * refcount on gem itself instead of f_count of dmabuf.
+ */
obj = dma_buf->priv;
- if (obj->dev == dev) {
- /*
- * Importing dmabuf exported from our own gem increases
- * refcount on gem itself instead of f_count of dmabuf.
- */
- drm_gem_object_get(obj);
- return obj;
- }
+ drm_gem_object_get(obj);
+ return obj;
}
if (!dev->driver->gem_prime_import_sg_table)
diff --git a/include/drm/drm_gem_shmem_helper.h
b/include/drm/drm_gem_shmem_helper.h
index b4f993da3cae..35f7466dca84 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -287,6 +287,8 @@ drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
struct sg_table *sgt);
int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev,
struct drm_mode_create_dumb *args);
+struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device
*dev,
+ struct dma_buf *buf);
/**
* DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations
@@ -298,4 +300,17 @@ int drm_gem_shmem_dumb_create(struct drm_file *file,
struct drm_device *dev,
.gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \
.dumb_create = drm_gem_shmem_dumb_create
+/**
+ * DRM_GEM_SHMEM_DRIVER_OPS_NO_MAP_SGT - shmem GEM operations
+ * without mapping sg_table on
+ * imported buffer.
+ *
+ * This macro provides a shortcut for setting the shmem GEM operations in
+ * the &drm_driver structure for drivers that do not require a sg_table on
+ * imported buffers.
+ */
+#define DRM_GEM_SHMEM_DRIVER_OPS_NO_MAP_SGT \
+ .gem_prime_import = drm_gem_shmem_prime_import_no_map, \
+ .dumb_create = drm_gem_shmem_dumb_create
+
#endif /* __DRM_GEM_SHMEM_HELPER_H__ */
diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
index fa085c44d4ca..f50f862f0d8b 100644
--- a/include/drm/drm_prime.h
+++ b/include/drm/drm_prime.h
@@ -100,6 +100,9 @@ struct dma_buf *drm_gem_prime_export(struct drm_gem_object
*obj,
unsigned long drm_prime_get_contiguous_size(struct sg_table *sgt);
/* helper functions for importing */
+bool drm_gem_is_prime_exported_dma_buf(struct drm_device *dev,
+ struct dma_buf *dma_buf);
+
struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
struct dma_buf *dma_buf,
struct device *attach_dev);
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
