linux-hardened/drivers/gpu/drm/i915
Chris Wilson 380996aab5 drm/i915: Use a task to cancel the userptr on invalidate_range
Whilst discussing possible ways to trigger an invalidate_range on a
userptr with an aliased GGTT mmapping (and so cause a struct_mutex
deadlock), the conclusion is that we can, and we must, prevent any
possible deadlock by avoiding taking the mutex at all during
invalidate_range. This has numerous advantages all of which stem from
avoid the sleeping function from inside the unknown context. In
particular, it simplifies the invalidate_range because we no longer
have to juggle the spinlock/mutex and can just hold the spinlock
for the entire walk. To compensate, we have to make get_pages a bit more
complicated in order to serialise with a pending cancel_userptr worker.
As we hold the struct_mutex, we have no choice but to return EAGAIN and
hope that the worker is then flushed before we retry after reacquiring
the struct_mutex.

The important caveat is that the invalidate_range itself is no longer
synchronous. There exists a small but definite period in time in which
the old PTE's page remain accessible via the GPU. Note however that the
physical pages themselves are not invalidated by the mmu_notifier, just
the CPU view of the address space. The impact should be limited to a
delay in pages being flushed, rather than a possibility of writing to
the wrong pages. The only race condition that this worsens is remapping
an userptr active on the GPU where fresh work may still reference the
old pages due to struct_mutex contention. Given that userspace is racing
with the GPU, it is fair to say that the results are undefined.

v2: Only queue (and importantly only take one refcnt) the worker once.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-10-06 14:15:30 +02:00
..
dvo.h drm/i915: Constify adjusted_mode 2015-09-30 10:20:11 +02:00
dvo_ch7xxx.c drm/i915: Constify adjusted_mode 2015-09-30 10:20:11 +02:00
dvo_ch7017.c drm/i915: Constify adjusted_mode 2015-09-30 10:20:11 +02:00
dvo_ivch.c drm/i915: Constify adjusted_mode 2015-09-30 10:20:11 +02:00
dvo_ns2501.c drm/i915: Constify adjusted_mode 2015-09-30 10:20:11 +02:00
dvo_sil164.c drm/i915: Constify adjusted_mode 2015-09-30 10:20:11 +02:00
dvo_tfp410.c drm/i915: Constify adjusted_mode 2015-09-30 10:20:11 +02:00
i915_cmd_parser.c drm/i915: Add GEN7_GPGPU_DISPATCHDIMX/Y/Z to the register whitelist 2015-10-06 10:40:22 +02:00
i915_debugfs.c drm/i915: unlock on error in i915_ppgtt_info() 2015-10-05 10:01:02 +02:00
i915_dma.c drm/i915/bdw: Check for slice, subslice and EU count for BDW 2015-09-30 14:13:03 +02:00
i915_drv.c drm/i915/guc: Add host2guc notification for suspend and resume 2015-10-06 10:32:22 +02:00
i915_drv.h drm/i915: Clean up associated VMAs on context destruction 2015-10-06 14:13:26 +02:00
i915_gem.c drm/i915: Clean up associated VMAs on context destruction 2015-10-06 14:13:26 +02:00
i915_gem_batch_pool.c
i915_gem_batch_pool.h
i915_gem_context.c drm/i915: Clean up associated VMAs on context destruction 2015-10-06 14:13:26 +02:00
i915_gem_debug.c drm/i915: Implement inter-engine read-read optimisations 2015-05-21 15:11:42 +02:00
i915_gem_dmabuf.c drm/i915: remove unused has_dma_mapping flag 2015-07-13 22:42:41 +02:00
i915_gem_evict.c
i915_gem_execbuffer.c drm/i915: Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset 2015-10-01 18:12:17 +02:00
i915_gem_fence.c drm/i915: Parametrize fence registers 2015-09-30 10:20:03 +02:00
i915_gem_gtt.c drm/i915: Add LO/HI PRIVATE_PAT registers 2015-09-30 10:20:13 +02:00
i915_gem_gtt.h drm/i915: prevent out of range pt in the PDE macros (take 3) 2015-10-06 14:15:29 +02:00
i915_gem_render_state.c drm/i915: Add provision to extend Golden context batch 2015-07-21 09:30:57 +02:00
i915_gem_render_state.h drm/i915: Add provision to extend Golden context batch 2015-07-21 09:30:57 +02:00
i915_gem_shrinker.c
i915_gem_stolen.c drm/i915: don't use the first stolen page on Broadwell 2015-09-30 10:20:05 +02:00
i915_gem_tiling.c Merge tag 'drm-intel-fixes-2015-08-14' into drm-intel-next-fixes 2015-08-14 18:11:30 +02:00
i915_gem_userptr.c drm/i915: Use a task to cancel the userptr on invalidate_range 2015-10-06 14:15:30 +02:00
i915_gpu_error.c drm/i915: rename INSTDONE1 to GEN4_INSTDONE1 2015-10-02 14:25:19 +02:00
i915_guc_reg.h drm/i915: Parametrize UOS_RSA_SCRATCH 2015-09-30 10:20:13 +02:00
i915_guc_submission.c drm/i915/guc: Add host2guc notification for suspend and resume 2015-10-06 10:32:22 +02:00
i915_ioc32.c Merge tag 'drm-intel-fixes-2015-07-15' into drm-intel-next-queued 2015-07-15 16:36:50 +02:00
i915_irq.c drm/i915: Use czclk_freq in vlv c0 residency calculations 2015-09-30 10:20:39 +02:00
i915_params.c drm/i915: Mark debug mod options as _unsafe 2015-09-22 17:10:53 +02:00
i915_reg.h drm/i915: Add GEN7_GPGPU_DISPATCHDIMX/Y/Z to the register whitelist 2015-10-06 10:40:22 +02:00
i915_suspend.c drm/i915: use dev_priv for the FBC functions 2015-07-08 11:39:45 +02:00
i915_sysfs.c drm/i915/bxt: fix RC6 residency time calculation 2015-09-30 17:15:13 +02:00
i915_trace.h drm/i915: cleanup pipe_update trace functions with new crtc debug info v3 2015-09-18 14:15:19 +03:00
i915_trace_points.c
i915_vgpu.c
i915_vgpu.h drm/i915: Update PV INFO page definition for Intel GVT-g 2015-09-02 11:46:12 +02:00
intel_acpi.c drm/i915: Spell vga_switcheroo consistently 2015-09-22 17:10:52 +02:00
intel_atomic.c drm/i915/ivb: Move WaCxSRDisabledForSpriteScaling w/a to atomic check 2015-09-30 17:15:42 +02:00
intel_atomic_plane.c drm/i915: Do not handle a null plane state. 2015-09-10 18:27:17 +02:00
intel_audio.c drm/i915: Constify adjusted_mode 2015-09-30 10:20:11 +02:00
intel_bios.c Merge remote-tracking branch 'airlied/drm-next' into drm-intel-next 2015-09-30 08:47:41 +02:00
intel_bios.h drm/i915: Ignore "digital output" and "not HDMI output" bits for eDP detection 2015-09-23 16:58:29 +02:00
intel_crt.c drm/i915: s/_FDI_RXA_.../FDI_RX_...(PIPE_A)/ 2015-09-30 17:15:11 +02:00
intel_csr.c drm/i915/skl: Added a check for the hardware status of csr fw before loading. 2015-09-30 10:14:22 +02:00
intel_ddi.c drm/i915: Rename DP link training functions 2015-10-06 10:53:52 +02:00
intel_display.c drm/i915/bxt: DSI encoder support in CRTC modeset 2015-10-02 14:27:55 +02:00
intel_dp.c drm/i915: Rename DP link training functions 2015-10-06 10:53:52 +02:00
intel_dp_mst.c drm/i915: Rename DP link training functions 2015-10-06 10:53:52 +02:00
intel_drv.h drm/i915: Rename DP link training functions 2015-10-06 10:53:52 +02:00
intel_dsi.c drm/i915/bxt: get DSI pixelclock 2015-10-02 14:45:51 +02:00
intel_dsi.h drm/i915/bxt: get DSI pixelclock 2015-10-02 14:45:51 +02:00
intel_dsi_panel_vbt.c drm/i915: s/dpio_lock/sb_lock/ 2015-05-28 11:13:51 +02:00
intel_dsi_pll.c drm/i915/bxt: vlv_dsi_reset_clocks() can be static 2015-10-06 10:57:06 +02:00
intel_dvo.c drm/i915: Constify adjusted_mode 2015-09-30 10:20:11 +02:00
intel_fbc.c drm/i915: export size_is_valid() from __intel_fbc_update() 2015-09-30 10:20:07 +02:00
intel_fbdev.c Merge remote-tracking branch 'airlied/drm-next' into drm-intel-next 2015-09-30 08:47:41 +02:00
intel_fifo_underrun.c
intel_frontbuffer.c drm/i915: fix FBC frontbuffer tracking flushing code 2015-08-05 09:59:44 +02:00
intel_guc.h drm/i915/guc: Add host2guc notification for suspend and resume 2015-10-06 10:32:22 +02:00
intel_guc_fwif.h drm/i915/guc: Add host2guc notification for suspend and resume 2015-10-06 10:32:22 +02:00
intel_guc_loader.c drm/i915/guc: Add host2guc notification for suspend and resume 2015-10-06 10:32:22 +02:00
intel_hdmi.c drm/i915: Add hot_plug hook for hdmi encoder 2015-10-06 10:52:22 +02:00
intel_hotplug.c drm/i915: Call encoder hotplug for init and resume cases 2015-10-06 10:25:55 +02:00
intel_i2c.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-06-26 13:18:51 -07:00
intel_lrc.c drm/i915: Remove extraneous request cancel. 2015-09-23 17:33:55 +02:00
intel_lrc.h drm/i915: Parametrize LRC registers 2015-09-23 17:13:01 +02:00
intel_lvds.c drm/i915: Always call the adjusted mode 'adjusted_mode' 2015-09-30 10:19:52 +02:00
intel_mocs.c drm/i915: Added Programming of the MOCS 2015-07-14 17:13:14 +02:00
intel_mocs.h drm/i915: Added Programming of the MOCS 2015-07-14 17:13:14 +02:00
intel_modes.c drm/i915: Add HDMI aspect ratio property for SDVO 2015-09-30 10:20:12 +02:00
intel_opregion.c drm/i915/bxt: DSI encoder support in CRTC modeset 2015-10-02 14:27:55 +02:00
intel_overlay.c drm/i915: Update intel_ring_begin() to take a request structure 2015-06-23 14:02:29 +02:00
intel_panel.c drm/i915/bxt: Modify BXT BLC according to VBT changes 2015-10-02 14:59:25 +02:00
intel_pm.c drm/i915: Update Promotion timer for RC6 TO Mode 2015-10-06 10:34:27 +02:00
intel_psr.c drm/i915: VLV/CHV PSR: Increase wait delay time before active PSR. 2015-08-05 10:07:44 +02:00
intel_renderstate.h
intel_renderstate_gen6.c
intel_renderstate_gen7.c
intel_renderstate_gen8.c
intel_renderstate_gen9.c
intel_ringbuffer.c drm/i915/gen8: Move WaHdcDisableFetchWhenMasked to common init fn 2015-09-30 10:20:34 +02:00
intel_ringbuffer.h drm/i915: Refactor common ringbuffer allocation code 2015-09-04 10:17:00 +02:00
intel_runtime_pm.c drm/i915: Skip CHV PHY asserts until PHY has been fully reset 2015-10-06 10:29:40 +02:00
intel_sdvo.c drm/i915: Call encoder hotplug for init and resume cases 2015-10-06 10:25:55 +02:00
intel_sdvo_regs.h
intel_sideband.c drm/i915: s/dpio_lock/sb_lock/ 2015-05-28 11:13:51 +02:00
intel_sprite.c drm/i915: Drop intel_update_sprite_watermarks 2015-09-30 17:15:47 +02:00
intel_tv.c Merge remote-tracking branch 'airlied/drm-next' into drm-intel-next 2015-09-30 08:47:41 +02:00
intel_uncore.c drm/i915: Include MCHBAR_MIRROR_BASE in ILK_GDSR 2015-09-30 10:20:15 +02:00
Kconfig drm/i915: Use CONFIG_DRM_FBDEV_EMULATION 2015-08-11 14:00:29 +02:00
Makefile Merge tag 'drm-intel-next-fixes-2015-09-02' into drm-intel-next-queued 2015-09-02 14:33:42 +02:00