Merge tag 'drm-next-2021-11-03' of git://anongit.freedesktop.org/drm/drm

Pull drm updates from Dave Airlie:
 "Summary below. i915 starts to add support for DG2 GPUs, enables DG1
  and ADL-S support by default, lots of work to enable DisplayPort 2.0
  across drivers. Lots of documentation updates and fixes across the
  board.

  core:
   - improve dma_fence, lease and resv documentation
   - shmem-helpers: allocate WC pages on x86, use vmf_insert_pin
   - sched fixes/improvements
   - allow empty drm leases
   - add dma resv iterator
   - add more DP 2.0 headers
   - DP MST helper improvements for DP2.0

  dma-buf:
   - avoid warnings, remove fence trace macros

  bridge:
   - new helper to get rid of panels
   - probe improvements for it66121
   - enable DSI EOTP for anx7625

  fbdev:
   - efifb: release runtime PM on destroy

  ttm:
   - kerneldoc switch
   - helper to clear all DMA mappings
   - pool shrinker optimizaton
   - remove ttm_tt_destroy_common
   - update ttm_move_memcpy for async use

  panel:
   - add new panel-edp driver

  amdgpu:
   - Initial DP 2.0 support
   - Initial USB4 DP tunnelling support
   - Aldebaran MCE support
   - Modifier support for DCC image stores for GFX 10.3
   - Display rework for better FP code handling
   - Yellow Carp/Cyan Skillfish updates
   - Cyan Skillfish display support
   - convert vega/navi to IP discovery asic enumeration
   - validate IP discovery table
   - RAS improvements
   - Lots of fixes

  i915:
   - DG1 PCI IDs + LMEM discovery/placement
   - DG1 GuC submission by default
   - ADL-S PCI IDs updated + enabled by default
   - ADL-P (XE_LPD) fixed and updates
   - DG2 display fixes
   - PXP protected object support for Gen12 integrated
   - expose multi-LRC submission interface for GuC
   - export logical engine instance to user
   - Disable engine bonding on Gen12+
   - PSR cleanup
   - PSR2 selective fetch by default
   - DP 2.0 prep work
   - VESA vendor block + MSO use of it
   - FBC refactor
   - try again to fix fast-narrow vs slow-wide eDP training
   - use THP when IOMMU enabled
   - LMEM backup/restore for suspend/resume
   - locking simplification
   - GuC major reworking
   - async flip VT-D workaround changes
   - DP link training improvements
   - misc display refactorings

  bochs:
   - new PCI ID

  rcar-du:
   - Non-contiguious buffer import support for rcar-du
   - r8a779a0 support prep

  omapdrm:
   - COMPILE_TEST fixes

  sti:
   - COMPILE_TEST fixes

  msm:
   - fence ordering improvements
   - eDP support in DP sub-driver
   - dpu irq handling cleanup
   - CRC support for making igt happy
   - NO_CONNECTOR bridge support
   - dsi: 14nm phy support for msm8953
   - mdp5: msm8x53, sdm450, sdm632 support

  stm:
   - layer alpha + zpo support

  v3d:
   - fix Vulkan CTS failure
   - support multiple sync objects

  gud:
   - add R8/RGB332/RGB888 pixel formats

  vc4:
   - convert to new bridge helpers

  vgem:
   - use shmem helpers

  virtio:
   - support mapping exported vram

  zte:
   - remove obsolete driver

  rockchip:
   - use bridge attach no connector for LVDS/RGB"

* tag 'drm-next-2021-11-03' of git://anongit.freedesktop.org/drm/drm: (1259 commits)
  drm/amdgpu/gmc6: fix DMA mask from 44 to 40 bits
  drm/amd/display: MST support for DPIA
  drm/amdgpu: Fix even more out of bound writes from debugfs
  drm/amdgpu/discovery: add SDMA IP instance info for soc15 parts
  drm/amdgpu/discovery: add UVD/VCN IP instance info for soc15 parts
  drm/amdgpu/UAPI: rearrange header to better align related items
  drm/amd/display: Enable dpia in dmub only for DCN31 B0
  drm/amd/display: Fix USB4 hot plug crash issue
  drm/amd/display: Fix deadlock when falling back to v2 from v3
  drm/amd/display: Fallback to clocks which meet requested voltage on DCN31
  drm/amd/display: move FPU associated DCN301 code to DML folder
  drm/amd/display: fix link training regression for 1 or 2 lane
  drm/amd/display: add two lane settings training options
  drm/amd/display: decouple hw_lane_settings from dpcd_lane_settings
  drm/amd/display: implement decide lane settings
  drm/amd/display: adopt DP2.0 LT SCR revision 8
  drm/amd/display: FEC configuration for dpia links in MST mode
  drm/amd/display: FEC configuration for dpia links
  drm/amd/display: Add workaround flag for EDID read on certain docks
  drm/amd/display: Set phy_mux_sel bit in dmub scratch register
  ...

1 files changed, 15 insertions, 0 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 306229c4313f..71f178f85f5b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -687,6 +687,21 @@ void unregister_shrinker(struct shrinker *shrinker)
 }
 EXPORT_SYMBOL(unregister_shrinker);
 
+/**
+ * synchronize_shrinkers - Wait for all running shrinkers to complete.
+ *
+ * This is equivalent to calling unregister_shrink() and register_shrinker(),
+ * but atomically and with less overhead. This is useful to guarantee that all
+ * shrinker invocations have seen an update, before freeing memory, similar to
+ * rcu.
+ */
+void synchronize_shrinkers(void)
+{
+	down_write(&shrinker_rwsem);
+	up_write(&shrinker_rwsem);
+}
+EXPORT_SYMBOL(synchronize_shrinkers);
+
 #define SHRINK_BATCH 128
 
 static unsigned long do_shrink_slab(struct shrink_control *shrinkctl,