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2020-12-09locking/rwsem: Remove reader optimistic spinningWaiman Long
Reader optimistic spinning is helpful when the reader critical section is short and there aren't that many readers around. It also improves the chance that a reader can get the lock as writer optimistic spinning disproportionally favors writers much more than readers. Since commit d3681e269fff ("locking/rwsem: Wake up almost all readers in wait queue"), all the waiting readers are woken up so that they can all get the read lock and run in parallel. When the number of contending readers is large, allowing reader optimistic spinning will likely cause reader fragmentation where multiple smaller groups of readers can get the read lock in a sequential manner separated by writers. That reduces reader parallelism. One possible way to address that drawback is to limit the number of readers (preferably one) that can do optimistic spinning. These readers act as representatives of all the waiting readers in the wait queue as they will wake up all those waiting readers once they get the lock. Alternatively, as reader optimistic lock stealing has already enhanced fairness to readers, it may be easier to just remove reader optimistic spinning and simplifying the optimistic spinning code as a result. Performance measurements (locking throughput kops/s) using a locking microbenchmark with 50/50 reader/writer distribution and turbo-boost disabled was done on a 2-socket Cascade Lake system (48-core 96-thread) to see the impacts of these changes: 1) Vanilla - 5.10-rc3 kernel 2) Before - 5.10-rc3 kernel with previous patches in this series 2) limit-rspin - 5.10-rc3 kernel with limited reader spinning patch 3) no-rspin - 5.10-rc3 kernel with reader spinning disabled # of threads CS Load Vanilla Before limit-rspin no-rspin ------------ ------- ------- ------ ----------- -------- 2 1 5,185 5,662 5,214 5,077 4 1 5,107 4,983 5,188 4,760 8 1 4,782 4,564 4,720 4,628 16 1 4,680 4,053 4,567 3,402 32 1 4,299 1,115 1,118 1,098 64 1 3,218 983 1,001 957 96 1 1,938 944 957 930 2 20 2,008 2,128 2,264 1,665 4 20 1,390 1,033 1,046 1,101 8 20 1,472 1,155 1,098 1,213 16 20 1,332 1,077 1,089 1,122 32 20 967 914 917 980 64 20 787 874 891 858 96 20 730 836 847 844 2 100 372 356 360 355 4 100 492 425 434 392 8 100 533 537 529 538 16 100 548 572 568 598 32 100 499 520 527 537 64 100 466 517 526 512 96 100 406 497 506 509 The column "CS Load" represents the number of pause instructions issued in the locking critical section. A CS load of 1 is extremely short and is not likey in real situations. A load of 20 (moderate) and 100 (long) are more realistic. It can be seen that the previous patches in this series have reduced performance in general except in highly contended cases with moderate or long critical sections that performance improves a bit. This change is mostly caused by the "Prevent potential lock starvation" patch that reduce reader optimistic spinning and hence reduce reader fragmentation. The patch that further limit reader optimistic spinning doesn't seem to have too much impact on overall performance as shown in the benchmark data. The patch that disables reader optimistic spinning shows reduced performance at lightly loaded cases, but comparable or slightly better performance on with heavier contention. This patch just removes reader optimistic spinning for now. As readers are not going to do optimistic spinning anymore, we don't need to consider if the OSQ is empty or not when doing lock stealing. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Link: https://lkml.kernel.org/r/20201121041416.12285-6-longman@redhat.com
2020-12-09locking/rwsem: Enable reader optimistic lock stealingWaiman Long
If the optimistic spinning queue is empty and the rwsem does not have the handoff or write-lock bits set, it is actually not necessary to call rwsem_optimistic_spin() to spin on it. Instead, it can steal the lock directly as its reader bias is in the count already. If it is the first reader in this state, it will try to wake up other readers in the wait queue. With this patch applied, the following were the lock event counts after rebooting a 2-socket system and a "make -j96" kernel rebuild. rwsem_opt_rlock=4437 rwsem_rlock=29 rwsem_rlock_steal=19 So lock stealing represents about 0.4% of all the read locks acquired in the slow path. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Link: https://lkml.kernel.org/r/20201121041416.12285-4-longman@redhat.com
2020-12-09locking/rwsem: Prevent potential lock starvationWaiman Long
The lock handoff bit is added in commit 4f23dbc1e657 ("locking/rwsem: Implement lock handoff to prevent lock starvation") to avoid lock starvation. However, allowing readers to do optimistic spinning does introduce an unlikely scenario where lock starvation can happen. The lock handoff bit may only be set when a waiter is being woken up. In the case of reader unlock, wakeup happens only when the reader count reaches 0. If there is a continuous stream of incoming readers acquiring read lock via optimistic spinning, it is possible that the reader count may never reach 0 and so the handoff bit will never be asserted. One way to prevent this scenario from happening is to disallow optimistic spinning if the rwsem is currently owned by readers. If the previous or current owner is a writer, optimistic spinning will be allowed. If the previous owner is a reader but the reader count has reached 0 before, a wakeup should have been issued. So the handoff mechanism will be kicked in to prevent lock starvation. As a result, it should be OK to do optimistic spinning in this case. This patch may have some impact on reader performance as it reduces reader optimistic spinning especially if the lock critical sections are short the number of contending readers are small. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Link: https://lkml.kernel.org/r/20201121041416.12285-3-longman@redhat.com
2020-12-09locking/rwsem: Pass the current atomic count to rwsem_down_read_slowpath()Waiman Long
The atomic count value right after reader count increment can be useful to determine the rwsem state at trylock time. So the count value is passed down to rwsem_down_read_slowpath() to be used when appropriate. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Link: https://lkml.kernel.org/r/20201121041416.12285-2-longman@redhat.com
2020-12-09locking/rwsem: Fold __down_{read,write}*()Peter Zijlstra
There's a lot needless duplication in __down_{read,write}*(), cure that with a helper. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.net
2020-12-09locking/rwsem: Introduce rwsem_write_trylock()Peter Zijlstra
One copy of this logic is better than three. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.net
2020-12-09locking/rwsem: Better collate rwsem_read_trylock()Peter Zijlstra
All users of rwsem_read_trylock() do rwsem_set_reader_owned(sem) on success, move it into rwsem_read_trylock() proper. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.net
2020-12-09Merge branch 'locking/rwsem'Peter Zijlstra
2020-12-09rwsem: Implement down_read_interruptibleEric W. Biederman
In preparation for converting exec_update_mutex to a rwsem so that multiple readers can execute in parallel and not deadlock, add down_read_interruptible. This is needed for perf_event_open to be converted (with no semantic changes) from working on a mutex to wroking on a rwsem. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/87k0tybqfy.fsf@x220.int.ebiederm.org
2020-12-09rwsem: Implement down_read_killable_nestedEric W. Biederman
In preparation for converting exec_update_mutex to a rwsem so that multiple readers can execute in parallel and not deadlock, add down_read_killable_nested. This is needed so that kcmp_lock can be converted from working on a mutexes to working on rw_semaphores. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/87o8jabqh3.fsf@x220.int.ebiederm.org
2020-12-09Merge branch 'bpf-xdp-offload-fixes'Daniel Borkmann
Toke Høiland-Jørgensen says: ==================== This series restores the test_offload.py selftest to working order. It seems a number of subtle behavioural changes have crept into various subsystems which broke test_offload.py in a number of ways. Most of these are fairly benign changes where small adjustments to the test script seems to be the best fix, but one is an actual kernel bug that I've observed in the wild caused by a bad interaction between xdp_attachment_flags_ok() and the rework of XDP program handling in the core netdev code. Patch 1 fixes the bug by removing xdp_attachment_flags_ok(), and the reminder of the patches are adjustments to test_offload.py, including a new feature for netdevsim to force a BPF verification fail. Please see the individual patches for details. Changelog: v4: - Accidentally truncated the Fixes: hashes in patches 3/4 to 11 chars v3: - Add Fixes: tags v2: - Replace xdp_attachment_flags_ok() with a check in dev_xdp_attach() - Better packing of struct nsim_dev ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2020-12-09selftests/bpf/test_offload.py: Filter bpftool internal map when counting mapsToke Høiland-Jørgensen
A few of the tests in test_offload.py expects to see a certain number of maps created, and checks this by counting the number of maps returned by bpftool. There is already a filter that will remove any maps already there at the beginning of the test, but bpftool now creates a map for the PID iterator rodata on each invocation, which makes the map count wrong. Fix this by also filtering the pid_iter.rodata map by name when counting. Fixes: d53dee3fe013 ("tools/bpftool: Show info for processes holding BPF map/prog/link/btf FDs") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/bpf/160752226387.110217.9887866138149423444.stgit@toke.dk
2020-12-09selftests/bpf/test_offload.py: Reset ethtool features after failed settingToke Høiland-Jørgensen
When setting the ethtool feature flag fails (as expected for the test), the kernel now tracks that the feature was requested to be 'off' and refuses to subsequently disable it again. So reset it back to 'on' so a subsequent disable (that's not supposed to fail) can succeed. Fixes: 417ec26477a5 ("selftests/bpf: add offload test based on netdevsim") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/bpf/160752226280.110217.10696241563705667871.stgit@toke.dk
2020-12-09selftests/bpf/test_offload.py: Fix expected case of extack messagesToke Høiland-Jørgensen
Commit 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device") changed the case of some of the extack messages being returned when attaching of XDP programs failed. This broke test_offload.py, so let's fix the test to reflect this. Fixes: 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/bpf/160752226175.110217.11214100824416344952.stgit@toke.dk
2020-12-09selftests/bpf/test_offload.py: Only check verifier log on verification failsToke Høiland-Jørgensen
Since commit 6f8a57ccf851 ("bpf: Make verifier log more relevant by default"), the verifier discards log messages for successfully-verified programs. This broke test_offload.py which is looking for a verification message from the driver callback. Change test_offload.py to use the toggle in netdevsim to make the verification fail before looking for the verification message. Fixes: 6f8a57ccf851 ("bpf: Make verifier log more relevant by default") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/bpf/160752226069.110217.12370824996153348073.stgit@toke.dk
2020-12-09netdevsim: Add debugfs toggle to reject BPF programs in verifierToke Høiland-Jørgensen
This adds a new debugfs toggle ('bpf_bind_verifier_accept') that can be used to make netdevsim reject BPF programs from being accepted by the verifier. If this toggle (which defaults to true) is set to false, nsim_bpf_verify_insn() will return EOPNOTSUPP on the last instruction (after outputting the 'Hello from netdevsim' verifier message). This makes it possible to check the verification callback in the driver from test_offload.py in selftests, since the verifier now clears the verifier log on a successful load, hiding the message from the driver. Fixes: 6f8a57ccf851 ("bpf: Make verifier log more relevant by default") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/bpf/160752225964.110217.12584017165318065332.stgit@toke.dk
2020-12-09selftests/bpf/test_offload.py: Remove check for program load flags matchToke Høiland-Jørgensen
Since we just removed the xdp_attachment_flags_ok() callback, also remove the check for it in test_offload.py, and replace it with a test for the new ambiguity-avoid check when multiple programs are loaded. Fixes: 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/bpf/160752225858.110217.13036901876869496246.stgit@toke.dk
2020-12-09xdp: Remove the xdp_attachment_flags_ok() callbackToke Høiland-Jørgensen
Since commit 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device"), the XDP program attachment info is now maintained in the core code. This interacts badly with the xdp_attachment_flags_ok() check that prevents unloading an XDP program with different load flags than it was loaded with. In practice, two kinds of failures are seen: - An XDP program loaded without specifying a mode (and which then ends up in driver mode) cannot be unloaded if the program mode is specified on unload. - The dev_xdp_uninstall() hook always calls the driver callback with the mode set to the type of the program but an empty flags argument, which means the flags_ok() check prevents the program from being removed, leading to bpf prog reference leaks. The original reason this check was added was to avoid ambiguity when multiple programs were loaded. With the way the checks are done in the core now, this is quite simple to enforce in the core code, so let's add a check there and get rid of the xdp_attachment_flags_ok() callback entirely. Fixes: 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/bpf/160752225751.110217.10267659521308669050.stgit@toke.dk
2020-12-09drm/amdgpu: Initialise drm_gem_object_funcs for imported BOsAndrey Grodzovsky
For BOs imported from outside of amdgpu, setting of amdgpu_gem_object_funcs was missing in amdgpu_dma_buf_create_obj. Fix by refactoring BO creation and amdgpu_gem_object_funcs setting into single function called from both code paths. Fixes: d693def4fd1c ("drm: Remove obsolete GEM and PRIME callbacks from struct drm_driver") v2: Use use amdgpu_gem_object_create() directly v3: fix warning Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-09drm/amdgpu: fix size calculation with stolen vga memoryAlex Deucher
If we need to keep the stolen vga memory, make sure it is at least as big as the legacy vga size. Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2020-12-09drm/amd/pm: update smu10.h WORKLOAD_PPLIB setting for ravenChangfeng
When using old WORKLOAD_PPLIB setting in smu10.h, there is problem that it can't be able to switch to mak gpu clk during compute workload. It needs to update WORKLOAD_PPLIB setting to fix this issue. Signed-off-by: Changfeng <Changfeng.Zhu@amd.com> Reviewed-by: Huang Rui <ray.huang@amd.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2020-12-09drm/amdkfd: Fix leak in dmabuf importFelix Kuehling
Release dmabuf reference before returning from kfd_ioctl_import_dmabuf. amdgpu_amdkfd_gpuvm_import_dmabuf takes a reference to the underlying GEM BO and doesn't keep the reference to the dmabuf wrapper. Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com> Reviewed-by: Kent Russell <kent.russell@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-09drm/amdgpu: fix sdma instance fw version and feature version initStanley.Yang
each sdma instance fw_version and feature_version should be set right value when asic type isn't between SIENNA_CICHILD and CHIP_DIMGREY_CAVEFISH Signed-off-by: Stanley.Yang <Stanley.Yang@amd.com> Reviewed-by: Tao Zhou <tao.zhou1@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2020-12-09drm/amd/display: Add wm table for RenoirSung Lee
[Why] Without additional HostVM Latency, Renoir takes 2us longer to exit self-refresh. This causes underflow in certain cases. [How] Add table for Renoir with updated sr exit latencies for WM set A. Signed-off-by: Sung Lee <sung.lee@amd.com> Reviewed-by: Yongqiang Sun <yongqiang.sun@amd.com> Reviewed-by: Roman Li <Roman.Li@amd.com> Acked-by: Eryk Brol <eryk.brol@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-09drm/amd/display: Prevent bandwidth overflowChris Park
[Why] At very high pixel clock, bandwidth calculation exceeds 32 bit size and overflow value. This causes the resulting selection of link rate to be inaccurate. [How] Change order of operation and use fixed point to deal with integer accuracy. Also address bug found when forcing link rate. Signed-off-by: Chris Park <Chris.Park@amd.com> Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com> Acked-by: Eryk Brol <eryk.brol@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-09drm/amdgpu: fix debugfs creation/removal, againArnd Bergmann
There is still a warning when CONFIG_DEBUG_FS is disabled: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c:1145:13: error: 'amdgpu_ras_debugfs_create_ctrl_node' defined but not used [-Werror=unused-function] 1145 | static void amdgpu_ras_debugfs_create_ctrl_node(struct amdgpu_device *adev) Change the code again to make the compiler actually drop this code but not warn about it. Fixes: ae2bf61ff39e ("drm/amdgpu: guard ras debugfs creation/removal based on CONFIG_DEBUG_FS") Reviewed-by: Tao Zhou <tao.zhou1@amd.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-09drm/amdgpu/disply: set num_crtc earlierAlex Deucher
To avoid a recently added warning: Bogus possible_crtcs: [ENCODER:65:TMDS-65] possible_crtcs=0xf (full crtc mask=0x7) WARNING: CPU: 3 PID: 439 at drivers/gpu/drm/drm_mode_config.c:617 drm_mode_config_validate+0x178/0x200 [drm] In this case the warning is harmless, but confusing to users. Fixes: 0df108237433 ("drm: Validate encoder->possible_crtcs") Bug: https://bugzilla.kernel.org/show_bug.cgi?id=209123 Reviewed-by: Daniel Vetter <daniel@ffwll.ch> Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2020-12-09perf/imx_ddr: Add system PMU identifier for userspaceJoakim Zhang
The DDR Perf for i.MX8 is a system PMU whose AXI ID would different from SoC to SoC. Need expose system PMU identifier for userspace which refer to /sys/bus/event_source/devices/<PMU DEVICE>/identifier. Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com> Reviewed-by: John Garry <john.garry@huawei.com> Link: https://lore.kernel.org/r/20201130114202.26057-3-qiangqing.zhang@nxp.com Signed-off-by: Will Deacon <will@kernel.org>
2020-12-09bindings: perf: imx-ddr: add compatible stringJoakim Zhang
Add extra compabile string to support driver. Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com> Acked-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20201130114202.26057-2-qiangqing.zhang@nxp.com Signed-off-by: Will Deacon <will@kernel.org>
2020-12-09netfilter: nft_ct: Remove confirmation check for NFT_CT_IDBrett Mastbergen
Since commit 656c8e9cc1ba ("netfilter: conntrack: Use consistent ct id hash calculation") the ct id will not change from initialization to confirmation. Removing the confirmation check allows for things like adding an element to a 'typeof ct id' set in prerouting upon reception of the first packet of a new connection, and then being able to reference that set consistently both before and after the connection is confirmed. Fixes: 656c8e9cc1ba ("netfilter: conntrack: Use consistent ct id hash calculation") Signed-off-by: Brett Mastbergen <brett.mastbergen@gmail.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-12-09xen: don't use page->lru for ZONE_DEVICE memoryJuergen Gross
Commit 9e2369c06c8a18 ("xen: add helpers to allocate unpopulated memory") introduced usage of ZONE_DEVICE memory for foreign memory mappings. Unfortunately this collides with using page->lru for Xen backend private page caches. Fix that by using page->zone_device_data instead. Cc: <stable@vger.kernel.org> # 5.9 Fixes: 9e2369c06c8a18 ("xen: add helpers to allocate unpopulated memory") Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovksy@oracle.com> Reviewed-by: Jason Andryuk <jandryuk@gmail.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2020-12-09xen: add helpers for caching grant mapping pagesJuergen Gross
Instead of having similar helpers in multiple backend drivers use common helpers for caching pages allocated via gnttab_alloc_pages(). Make use of those helpers in blkback and scsiback. Cc: <stable@vger.kernel.org> # 5.9 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovksy@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2020-12-09gpio: eic-sprd: break loop when getting NULL device resourceChunyan Zhang
EIC controller have unfixed numbers of banks on different Spreadtrum SoCs, and each bank has its own base address, the loop of getting there base address in driver should break if the resource gotten via platform_get_resource() is NULL already. The later ones would be all NULL even if the loop continues. Fixes: 25518e024e3a ("gpio: Add Spreadtrum EIC driver support") Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com> Link: https://lore.kernel.org/r/20201209055106.840100-1-zhang.lyra@gmail.com Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-12-09membarrier: Execute SYNC_CORE on the calling threadAndy Lutomirski
membarrier()'s MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE is documented as syncing the core on all sibling threads but not necessarily the calling thread. This behavior is fundamentally buggy and cannot be used safely. Suppose a user program has two threads. Thread A is on CPU 0 and thread B is on CPU 1. Thread A modifies some text and calls membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE). Then thread B executes the modified code. If, at any point after membarrier() decides which CPUs to target, thread A could be preempted and replaced by thread B on CPU 0. This could even happen on exit from the membarrier() syscall. If this happens, thread B will end up running on CPU 0 without having synced. In principle, this could be fixed by arranging for the scheduler to issue sync_core_before_usermode() whenever switching between two threads in the same mm if there is any possibility of a concurrent membarrier() call, but this would have considerable overhead. Instead, make membarrier() sync the calling CPU as well. As an optimization, this avoids an extra smp_mb() in the default barrier-only mode and an extra rseq preempt on the caller. Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/r/250ded637696d490c69bef1877148db86066881c.1607058304.git.luto@kernel.org
2020-12-09membarrier: Explicitly sync remote cores when SYNC_CORE is requestedAndy Lutomirski
membarrier() does not explicitly sync_core() remote CPUs; instead, it relies on the assumption that an IPI will result in a core sync. On x86, this may be true in practice, but it's not architecturally reliable. In particular, the SDM and APM do not appear to guarantee that interrupt delivery is serializing. While IRET does serialize, IPI return can schedule, thereby switching to another task in the same mm that was sleeping in a syscall. The new task could then SYSRET back to usermode without ever executing IRET. Make this more robust by explicitly calling sync_core_before_usermode() on remote cores. (This also helps people who search the kernel tree for instances of sync_core() and sync_core_before_usermode() -- one might be surprised that the core membarrier code doesn't currently show up in a such a search.) Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/776b448d5f7bd6b12690707f5ed67bcda7f1d427.1607058304.git.luto@kernel.org
2020-12-09membarrier: Add an actual barrier before rseq_preempt()Andy Lutomirski
It seems that most RSEQ membarrier users will expect any stores done before the membarrier() syscall to be visible to the target task(s). While this is extremely likely to be true in practice, nothing actually guarantees it by a strict reading of the x86 manuals. Rather than providing this guarantee by accident and potentially causing a problem down the road, just add an explicit barrier. Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/d3e7197e034fa4852afcf370ca49c30496e58e40.1607058304.git.luto@kernel.org
2020-12-09x86/membarrier: Get rid of a dubious optimizationAndy Lutomirski
sync_core_before_usermode() had an incorrect optimization. If the kernel returns from an interrupt, it can get to usermode without IRET. It just has to schedule to a different task in the same mm and do SYSRET. Fortunately, there were no callers of sync_core_before_usermode() that could have had in_irq() or in_nmi() equal to true, because it's only ever called from the scheduler. While at it, clarify a related comment. Fixes: 70216e18e519 ("membarrier: Provide core serializing command, *_SYNC_CORE") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/5afc7632be1422f91eaf7611aaaa1b5b8580a086.1607058304.git.luto@kernel.org
2020-12-09pinctrl: intel: Actually disable Tx and Rx buffers on GPIO requestAndy Shevchenko
Mistakenly the buffers (input and output) become enabled together for a short period of time during GPIO request. This is problematic, because instead of initial motive to disable them in the commit af7e3eeb84e2 ("pinctrl: intel: Disable input and output buffer when switching to GPIO"), the driven value on the pin, which might be used as an IRQ line, brings firmwares of some touch pads to an awkward state that needs a full power off to recover. Fix this, as stated in the culprit commit, by disabling the buffers. Fixes: af7e3eeb84e2 ("pinctrl: intel: Disable input and output buffer when switching to GPIO") BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=210497 Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Link: https://lore.kernel.org/r/20201208182403.40435-1-andriy.shevchenko@linux.intel.com Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-12-08mm/madvise: remove racy mm ownership checkMinchan Kim
Jann spotted the security hole due to race of mm ownership check. If the task is sharing the mm_struct but goes through execve() before mm_access(), it could skip process_madvise_behavior_valid check. That makes *any advice hint* to reach into the remote process. This patch removes the mm ownership check. With it, it will lose the ability that local process could give *any* advice hint with vector interface for some reason (e.g., performance). Since there is no concrete example in upstream yet, it would be better to remove the abiliity at this moment and need to review when such new advice comes up. Fixes: ecb8ac8b1f14 ("mm/madvise: introduce process_madvise() syscall: an external memory hinting API") Reported-by: Jann Horn <jannh@google.com> Suggested-by: Jann Horn <jannh@google.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-08drm/amdgpu/powerplay: parse fan table for CI asicsAlex Deucher
Set up all the parameters required for SMU fan control if supported. Bug: https://bugzilla.kernel.org/show_bug.cgi?id=201539 Acked-by: Evan Quan <evan.quan@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2020-12-08drm/amdgpu: fix size calculation with stolen vga memoryAlex Deucher
If we need to keep the stolen vga memory, make sure it is at least as big as the legacy vga size. Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-08drm/amdgpu: remove amdgpu_ttm_late_init and amdgpu_bo_late_initAlex Deucher
No longer used. Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-08drm/amdgpu: free the pre-OS console framebuffer after the first modesetAlex Deucher
Rather than in late_init to avoid race conditions between freeing the buffers and the initial modeset. Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-08drm/amdgpu: enable runtime pm using BACO on CI dGPUsAlex Deucher
Works using BACO. Reviewed-by: Evan Quan <evan.quan@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-08drm/amdgpu/cik: enable BACO reset on BonaireAlex Deucher
Works now that the BACO sequence is fixed. Reviewed-by: Evan Quan <evan.quan@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-08drm/amd/pm: update smu10.h WORKLOAD_PPLIB setting for ravenChangfeng
When using old WORKLOAD_PPLIB setting in smu10.h, there is problem that it can't be able to switch to mak gpu clk during compute workload. It needs to update WORKLOAD_PPLIB setting to fix this issue. Signed-off-by: Changfeng <Changfeng.Zhu@amd.com> Reviewed-by: Huang Rui <ray.huang@amd.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-08drm/amd/pm: remove one unsupported smu function for vangoghXiaojian Du
This patch is to remove one unsupported smu function, this function will set the smu feature mask to disable all smu features in exception. Because vangogh doesn't support to set the smu feature mask by driver software, so this function is invalid for vangogh. Signed-off-by: Xiaojian Du <Xiaojian.Du@amd.com> Reviewed-by: Evan Quan <evan.quan@amd.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-08drm/amd/display: setup system context for APUsRoman Li
[Why] Scatter/gather is APU feature. But in dm it is limited only to Renoir. Now we need it for Vangogh. [How] Apply system context setup in dm_init to all APUs. Signed-off-by: Roman Li <roman.li@amd.com> Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-08drm/amd/display: add S/G support for VangoghRoman Li
[Why] Scatter/gather feature is supported on Vangogh. [How] Add GTT domain support for Vangogh to enable display buffers in system memory. Signed-off-by: Roman Li <roman.li@amd.com> Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2020-12-08drm/amdkfd: Fix leak in dmabuf importFelix Kuehling
Release dmabuf reference before returning from kfd_ioctl_import_dmabuf. amdgpu_amdkfd_gpuvm_import_dmabuf takes a reference to the underlying GEM BO and doesn't keep the reference to the dmabuf wrapper. Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com> Reviewed-by: Kent Russell <kent.russell@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>