1
Commit Graph

493 Commits

Author SHA1 Message Date
Linus Torvalds
de848da12f drm next for 6.12-rc1
string:
 - add mem_is_zero()
 
 core:
 - support more device numbers
 - use XArray for minor ids
 - add backlight constants
 - Split dma fence array creation into alloc and arm
 
 fbdev:
 - remove usage of old fbdev hooks
 
 kms:
 - Add might_fault() to drm_modeset_lock priming
 - Add dynamic per-crtc vblank configuration support
 
 dma-buf:
 - docs cleanup
 
 buddy:
 - Add start address support for trim function
 
 printk:
 - pass description to kmsg_dump
 
 scheduler;
 - Remove full_recover from drm_sched_start
 
 ttm:
 - Make LRU walk restartable after dropping locks
 - Allow direct reclaim to allocate local memory
 
 panic:
 - add display QR code (in rust)
 
 displayport:
 - mst: GUID improvements
 
 bridge:
 - Silence error message on -EPROBE_DEFER
 - analogix: Clean aup
 - bridge-connector: Fix double free
 - lt6505: Disable interrupt when powered off
 - tc358767: Make default DP port preemphasis configurable
 - lt9611uxc: require DRM_BRIDGE_ATTACH_NO_CONNECTOR
 - anx7625: simplify OF array handling
 - dw-hdmi: simplify clock handling
 - lontium-lt8912b: fix mode validation
 - nwl-dsi: fix mode vsync/hsync polarity
 
 xe:
 - Enable LunarLake and Battlemage support
 - Introducing Xe2 ccs modifiers for integrated and discrete graphics
 - rename xe perf to xe observation
 - use wb caching on DGFX for system memory
 - add fence timeouts
 - Lunar Lake graphics/media/display workarounds
 - Battlemage workarounds
 - Battlemage GSC support
 - GSC and HuC fw updates for LL/BM
 - use dma_fence_chain_free
 - refactor hw engine lookup and mmio access
 - enable priority mem read for Xe2
 - Add first GuC BMG fw
 - fix dma-resv lock
 - Fix DGFX display suspend/resume
 - Use xe_managed for kernel BOs
 - Use reserved copy engine for user binds on faulting devices
 - Allow mixing dma-fence jobs and long-running faulting jobs
 - fix media TLB invalidation
 - fix rpm in TTM swapout path
 - track resources and VF state by PF
 
 i915:
 - Type-C programming fix for MTL+
 - FBC cleanup
 - Calc vblank delay more accurately
 - On DP MST, Enable LT fallback for UHBR<->non-UHBR rates
 - Fix DP LTTPR detection
 - limit relocations to INT_MAX
 - fix long hangs in buddy allocator on DG2/A380
 
 amdgpu:
 - Per-queue reset support
 - SDMA devcoredump support
 - DCN 4.0.1 updates
 - GFX12/VCN4/JPEG4 updates
 - Convert vbios embedded EDID to drm_edid
 - GFX9.3/9.4 devcoredump support
 - process isolation framework for GFX 9.4.3/4
 - take IOMMU mappings into account for P2P DMA
 
 amdkfd:
 - CRIU fixes
 - HMM fix
 - Enable process isolation support for GFX 9.4.3/4
 - Allow users to target recommended SDMA engines
 - KFD support for targetting queues on recommended SDMA engines
 
 radeon:
 - remove .load and drm_dev_alloc
 - Fix vbios embedded EDID size handling
 - Convert vbios embedded EDID to drm_edid
 - Use GEM references instead of TTM
 - r100 cp init cleanup
 - Fix potential overflows in evergreen CS offset tracking
 
 msm:
 - DPU:
 - implement DP/PHY mapping on SC8180X
 - Enable writeback on SM8150, SC8180X, SM6125, SM6350
 - DP:
 - Enable widebus on all relevant chipsets
 - MSM8998 HDMI support
 - GPU:
 - A642L speedbin support
 - A615/A306/A621 support
 - A7xx devcoredump support
 
 ast:
 - astdp: Support AST2600 with VGA
 - Clean up HPD
 - Fix timeout loop for DP link training
 - reorganize output code by type (VGA, DP, etc)
 - convert to struct drm_edid
 - fix BMC handling for all outputs
 
 exynos:
 - drop stale MAINTAINERS pattern
 - constify struct
 
 loongson:
 - use GEM refcount over TTM
 
 mgag200:
 - Improve BMC handling
 - Support VBLANK intterupts
 - transparently support BMC outputs
 
 nouveau:
 - Refactor and clean up internals
 - Use GEM refcount over TTM's
 
 gm12u320:
 - convert to struct drm_edid
 
 gma500:
 - update i2c terms
 
 lcdif:
 - pixel clock fix
 
 host1x:
 - fix syncpoint IRQ during resume
 - use iommu_paging_domain_alloc()
 
 imx:
 - ipuv3: convert to struct drm_edid
 
 omapdrm:
 - improve error handling
 - use common helper for_each_endpoint_of_node()
 
 panel:
 - add support for BOE TV101WUM-LL2 plus DT bindings
 - novatek-nt35950: improve error handling
 - nv3051d: improve error handling
 - panel-edp: add support for BOE NE140WUM-N6G; revert support for
   SDC ATNA45AF01
 - visionox-vtdr6130: improve error handling; use
   devm_regulator_bulk_get_const()
 - boe-th101mb31ig002: Support for starry-er88577 MIPI-DSI panel plus
   DT; Fix porch parameter
 - edp: Support AOU B116XTN02.3, AUO B116XAN06.1, AOU B116XAT04.1,
   BOE NV140WUM-N41, BOE NV133WUM-N63, BOE NV116WHM-A4D, CMN N116BCA-EA2,
   CMN N116BCP-EA2, CSW MNB601LS1-4
 - himax-hx8394: Support Microchip AC40T08A MIPI Display panel plus DT
 - ilitek-ili9806e: Support Densitron DMT028VGHMCMI-1D TFT plus DT
 - jd9365da: Support Melfas lmfbx101117480 MIPI-DSI panel plus DT; Refactor
   for code sharing
 - panel-edp: fix name for HKC MB116AN01
 - jd9365da: fix "exit sleep" commands
 - jdi-fhd-r63452: simplify error handling with DSI multi-style
   helpers
 - mantix-mlaf057we51: simplify error handling with DSI multi-style
   helpers
 - simple:
   support Innolux G070ACE-LH3 plus DT bindings
   support On Tat Industrial Company KD50G21-40NT-A1 plus DT bindings
 - st7701:
   decouple DSI and DRM code
   add SPI support
   support Anbernic RG28XX plus DT bindings
 
 mediatek:
 - support alpha blending
 - remove cl in struct cmdq_pkt
 - ovl adaptor fix
 - add power domain binding for mediatek DPI controller
 
 renesas:
 - rz-du: add support for RZ/G2UL plus DT bindings
 
 rockchip:
 - Improve DP sink-capability reporting
 - dw_hdmi: Support 4k@60Hz
 - vop: Support RGB display on Rockchip RK3066; Support 4096px width
 
 sti:
 - convert to struct drm_edid
 
 stm:
 - Avoid UAF wih managed plane and CRTC helpers
 - Fix module owner
 - Fix error handling in probe
 - Depend on COMMON_CLK
 - ltdc: Fix transparency after disabling plane; Remove unused interrupt
 
 tegra:
 - gr3d: improve PM domain handling
 - convert to struct drm_edid
 - Call drm_atomic_helper_shutdown()
 
 vc4:
 - fix PM during detect
 - replace DRM_ERROR() with drm_error()
 - v3d: simplify clock retrieval
 
 v3d:
 - Clean up perfmon
 
 virtio:
 - add DRM capset
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Merge tag 'drm-next-2024-09-19' of https://gitlab.freedesktop.org/drm/kernel

Pull drm updates from Dave Airlie:
 "This adds a couple of patches outside the drm core, all should be
  acked appropriately, the string and pstore ones are the main ones that
  come to mind.

  Otherwise it's the usual drivers, xe is getting enabled by default on
  some new hardware, we've changed the device number handling to allow
  more devices, and we added some optional rust code to create QR codes
  in the panic handler, an idea first suggested I think 10 years ago :-)

  string:
   - add mem_is_zero()

  core:
   - support more device numbers
   - use XArray for minor ids
   - add backlight constants
   - Split dma fence array creation into alloc and arm

  fbdev:
   - remove usage of old fbdev hooks

  kms:
   - Add might_fault() to drm_modeset_lock priming
   - Add dynamic per-crtc vblank configuration support

  dma-buf:
   - docs cleanup

  buddy:
   - Add start address support for trim function

  printk:
   - pass description to kmsg_dump

  scheduler:
   - Remove full_recover from drm_sched_start

  ttm:
   - Make LRU walk restartable after dropping locks
   - Allow direct reclaim to allocate local memory

  panic:
   - add display QR code (in rust)

  displayport:
   - mst: GUID improvements

  bridge:
   - Silence error message on -EPROBE_DEFER
   - analogix: Clean aup
   - bridge-connector: Fix double free
   - lt6505: Disable interrupt when powered off
   - tc358767: Make default DP port preemphasis configurable
   - lt9611uxc: require DRM_BRIDGE_ATTACH_NO_CONNECTOR
   - anx7625: simplify OF array handling
   - dw-hdmi: simplify clock handling
   - lontium-lt8912b: fix mode validation
   - nwl-dsi: fix mode vsync/hsync polarity

  xe:
   - Enable LunarLake and Battlemage support
   - Introducing Xe2 ccs modifiers for integrated and discrete graphics
   - rename xe perf to xe observation
   - use wb caching on DGFX for system memory
   - add fence timeouts
   - Lunar Lake graphics/media/display workarounds
   - Battlemage workarounds
   - Battlemage GSC support
   - GSC and HuC fw updates for LL/BM
   - use dma_fence_chain_free
   - refactor hw engine lookup and mmio access
   - enable priority mem read for Xe2
   - Add first GuC BMG fw
   - fix dma-resv lock
   - Fix DGFX display suspend/resume
   - Use xe_managed for kernel BOs
   - Use reserved copy engine for user binds on faulting devices
   - Allow mixing dma-fence jobs and long-running faulting jobs
   - fix media TLB invalidation
   - fix rpm in TTM swapout path
   - track resources and VF state by PF

  i915:
   - Type-C programming fix for MTL+
   - FBC cleanup
   - Calc vblank delay more accurately
   - On DP MST, Enable LT fallback for UHBR<->non-UHBR rates
   - Fix DP LTTPR detection
   - limit relocations to INT_MAX
   - fix long hangs in buddy allocator on DG2/A380

  amdgpu:
   - Per-queue reset support
   - SDMA devcoredump support
   - DCN 4.0.1 updates
   - GFX12/VCN4/JPEG4 updates
   - Convert vbios embedded EDID to drm_edid
   - GFX9.3/9.4 devcoredump support
   - process isolation framework for GFX 9.4.3/4
   - take IOMMU mappings into account for P2P DMA

  amdkfd:
   - CRIU fixes
   - HMM fix
   - Enable process isolation support for GFX 9.4.3/4
   - Allow users to target recommended SDMA engines
   - KFD support for targetting queues on recommended SDMA engines

  radeon:
   - remove .load and drm_dev_alloc
   - Fix vbios embedded EDID size handling
   - Convert vbios embedded EDID to drm_edid
   - Use GEM references instead of TTM
   - r100 cp init cleanup
   - Fix potential overflows in evergreen CS offset tracking

  msm:
   - DPU:
      - implement DP/PHY mapping on SC8180X
      - Enable writeback on SM8150, SC8180X, SM6125, SM6350
   - DP:
      - Enable widebus on all relevant chipsets
      - MSM8998 HDMI support
   - GPU:
      - A642L speedbin support
      - A615/A306/A621 support
      - A7xx devcoredump support

  ast:
   - astdp: Support AST2600 with VGA
   - Clean up HPD
   - Fix timeout loop for DP link training
   - reorganize output code by type (VGA, DP, etc)
   - convert to struct drm_edid
   - fix BMC handling for all outputs

  exynos:
   - drop stale MAINTAINERS pattern
   - constify struct

  loongson:
   - use GEM refcount over TTM

  mgag200:
   - Improve BMC handling
   - Support VBLANK intterupts
   - transparently support BMC outputs

  nouveau:
   - Refactor and clean up internals
   - Use GEM refcount over TTM's

  gm12u320:
   - convert to struct drm_edid

  gma500:
   - update i2c terms

  lcdif:
   - pixel clock fix

  host1x:
   - fix syncpoint IRQ during resume
   - use iommu_paging_domain_alloc()

  imx:
   - ipuv3: convert to struct drm_edid

  omapdrm:
   - improve error handling
   - use common helper for_each_endpoint_of_node()

  panel:
   - add support for BOE TV101WUM-LL2 plus DT bindings
   - novatek-nt35950: improve error handling
   - nv3051d: improve error handling
   - panel-edp:
      - add support for BOE NE140WUM-N6G
      - revert support for SDC ATNA45AF01
   - visionox-vtdr6130:
      - improve error handling
      - use devm_regulator_bulk_get_const()
   - boe-th101mb31ig002:
      - Support for starry-er88577 MIPI-DSI panel plus DT
      - Fix porch parameter
   - edp: Support AOU B116XTN02.3, AUO B116XAN06.1, AOU B116XAT04.1, BOE
     NV140WUM-N41, BOE NV133WUM-N63, BOE NV116WHM-A4D, CMN N116BCA-EA2,
     CMN N116BCP-EA2, CSW MNB601LS1-4
   - himax-hx8394: Support Microchip AC40T08A MIPI Display panel plus DT
   - ilitek-ili9806e: Support Densitron DMT028VGHMCMI-1D TFT plus DT
   - jd9365da:
      - Support Melfas lmfbx101117480 MIPI-DSI panel plus DT
      - Refactor for code sharing
   - panel-edp: fix name for HKC MB116AN01
   - jd9365da: fix "exit sleep" commands
   - jdi-fhd-r63452: simplify error handling with DSI multi-style
     helpers
   - mantix-mlaf057we51: simplify error handling with DSI multi-style
     helpers
   - simple:
      - support Innolux G070ACE-LH3 plus DT bindings
      - support On Tat Industrial Company KD50G21-40NT-A1 plus DT
        bindings
   - st7701:
      - decouple DSI and DRM code
      - add SPI support
      - support Anbernic RG28XX plus DT bindings

  mediatek:
   - support alpha blending
   - remove cl in struct cmdq_pkt
   - ovl adaptor fix
   - add power domain binding for mediatek DPI controller

  renesas:
   - rz-du: add support for RZ/G2UL plus DT bindings

  rockchip:
   - Improve DP sink-capability reporting
   - dw_hdmi: Support 4k@60Hz
   - vop:
      - Support RGB display on Rockchip RK3066
      - Support 4096px width

  sti:
   - convert to struct drm_edid

  stm:
   - Avoid UAF wih managed plane and CRTC helpers
   - Fix module owner
   - Fix error handling in probe
   - Depend on COMMON_CLK
   - ltdc:
      - Fix transparency after disabling plane
      - Remove unused interrupt

  tegra:
   - gr3d: improve PM domain handling
   - convert to struct drm_edid
   - Call drm_atomic_helper_shutdown()

  vc4:
   - fix PM during detect
   - replace DRM_ERROR() with drm_error()
   - v3d: simplify clock retrieval

  v3d:
   - Clean up perfmon

  virtio:
   - add DRM capset"

* tag 'drm-next-2024-09-19' of https://gitlab.freedesktop.org/drm/kernel: (1326 commits)
  drm/xe: Fix missing conversion to xe_display_pm_runtime_resume
  drm/xe/xe2hpg: Add Wa_15016589081
  drm/xe: Don't keep stale pointer to bo->ggtt_node
  drm/xe: fix missing 'xe_vm_put'
  drm/xe: fix build warning with CONFIG_PM=n
  drm/xe: Suppress missing outer rpm protection warning
  drm/xe: prevent potential UAF in pf_provision_vf_ggtt()
  drm/amd/display: Add all planes on CRTC to state for overlay cursor
  drm/i915/bios: fix printk format width
  drm/i915/display: Fix BMG CCS modifiers
  drm/amdgpu: get rid of bogus includes of fdtable.h
  drm/amdkfd: CRIU fixes
  drm/amdgpu: fix a race in kfd_mem_export_dmabuf()
  drm: new helper: drm_gem_prime_handle_to_dmabuf()
  drm/amdgpu/atomfirmware: Silence UBSAN warning
  drm/amdgpu: Fix kdoc entry in 'amdgpu_vm_cpu_prepare'
  drm/amd/amdgpu: apply command submission parser for JPEG v1
  drm/amd/amdgpu: apply command submission parser for JPEG v2+
  drm/amd/pm: fix the pp_dpm_pcie issue on smu v14.0.2/3
  drm/amd/pm: update the features set on smu v14.0.2/3
  ...
2024-09-19 10:18:15 +02:00
Linus Torvalds
c903327d32 printk changes for 6.12
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Merge tag 'printk-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:
 "This is the "last" part of the support for the new nbcon consoles.
  Where "nbcon" stays for "No Big console lock CONsoles" aka not under
  the console_lock.

  New callbacks are added to struct console:

   - write_thread() for flushing nbcon consoles in task context.

   - write_atomic() for flushing nbcon consoles in atomic context,
     including NMI.

   - con->device_lock() and device_unlock() for taking the driver
     specific lock, for example, port->lock.

  New printk-specific kthreads are created:

   - per-console kthreads which get responsible for flushing normal
     priority messages on nbcon consoles.

   - thread which gets responsible for flushing normal priority messages
     on all consoles when CONFIG_RT enabled.

  The new callbacks are called under a special per-console lock which
  has already been added back in v6.7. It allows to distinguish three
  severities: normal, emergency, and panic. A context with a higher
  priority could take over the ownership when it is safe even in the
  middle of handling a record. The panic context could do it even when
  it is not safe. But it is allowed only for the final desperate flush
  before entering the infinite loop.

  The new lock helps to flush the messages directly in emergency and
  panic contexts. But it is not enough in all situations:

   - console_lock() is still need for synchronization against boot
     consoles.

   - con->device_lock() is need for synchronization against other
     operations on the same HW, e.g. serial port speed setting,
     non-printk related read/write.

  The dependency on con->device_lock() is mutual. Any code taking the
  driver specific lock has to acquire the related nbcon console context
  as well. For example, see the new uart_port_lock() API. It provides
  the necessary synchronization against emergency and panic contexts
  where the messages are flushed only under the new per-console lock.

  Maybe surprisingly, a quite tricky part is the decision how to flush
  the consoles in various situations. It has to take into account:

   - message priority:    normal, emergency, panic

   - scheduling context:  task, atomic, deferred_legacy

   - registered consoles: boot, legacy, nbcon

   - threads are running: early boot, suspend, shutdown, panic

   - caller:              printk(), pr_flush(), printk_flush_in_panic(),
                          console_unlock(), console_start(), ...

  The primary decision is made in printk_get_console_flush_type(). It
  creates a hint what the caller should do:

   - flush nbcon consoles directly or via the kthread

   - call the legacy loop (console_unlock()) directly or via irq_work

  The existing behavior is preserved for the legacy consoles. The only
  exception is that they are not longer flushed directly from printk()
  in panic() before CPUs are stopped. But this blocking happens only
  when at least one nbcon console is registered. The motivation is to
  increase a chance to produce the crash dump. They legacy consoles
  might create a deadlock in compare with nbcon consoles. The nbcon
  console should allow to see the messages even when the crash dump
  fails.

  There are three possible ways how nbcon consoles are flushed:

   - The per-nbcon-console kthread is responsible for flushing messages
     added with the normal priority. This is the default mode.

   - The legacy loop, aka console_unlock(), is used when there is still
     a boot console registered. There is no easy way how to match an
     early console driver with a nbcon console driver. And the
     console_lock() provides the only reliable serialization at the
     moment.

     The legacy loop uses either con->write_atomic() or
     con->write_thread() callbacks depending on whether it is allowed to
     schedule. The atomic variant has to be used from printk().

   - In other situations, the messages are flushed directly using
     write_atomic() which can be called in any context, including NMI.
     It is primary needed during early boot or shutdown, in emergency
     situations, and panic.

  The emergency priority is used by a code called within
  nbcon_cpu_emergency_enter()/exit(). At the moment, it is used in four
  situations: WARN(), Oops, lockdep, and RCU stall reports.

  Finally, there is no nbcon console at the moment. It means that the
  changes should _not_ modify the existing behavior. The only exception
  is CONFIG_RT which would force offloading the legacy loop, for normal
  priority context, into the dedicated kthread"

* tag 'printk-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (54 commits)
  printk: Avoid false positive lockdep report for legacy printing
  printk: nbcon: Assign nice -20 for printing threads
  printk: Implement legacy printer kthread for PREEMPT_RT
  tty: sysfs: Add nbcon support for 'active'
  proc: Add nbcon support for /proc/consoles
  proc: consoles: Add notation to c_start/c_stop
  printk: nbcon: Show replay message on takeover
  printk: Provide helper for message prepending
  printk: nbcon: Rely on kthreads for normal operation
  printk: nbcon: Use thread callback if in task context for legacy
  printk: nbcon: Relocate nbcon_atomic_emit_one()
  printk: nbcon: Introduce printer kthreads
  printk: nbcon: Init @nbcon_seq to highest possible
  printk: nbcon: Add context to usable() and emit()
  printk: Flush console on unregister_console()
  printk: Fail pr_flush() if before SYSTEM_SCHEDULING
  printk: nbcon: Add function for printers to reacquire ownership
  printk: nbcon: Use raw_cpu_ptr() instead of open coding
  printk: Use the BITS_PER_LONG macro
  lockdep: Mark emergency sections in lockdep splats
  ...
2024-09-17 08:52:28 +02:00
Yu Liao
3e5b2e81f1 printk: Export match_devname_and_update_preferred_console()
When building serial_base as a module, modpost fails with the following
error message:

  ERROR: modpost: "match_devname_and_update_preferred_console"
  [drivers/tty/serial/serial_base.ko] undefined!

Export the symbol to allow using it from modules.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409071312.qlwtTOS1-lkp@intel.com/
Fixes: 12c91cec31 ("serial: core: Add serial_base_match_and_update_preferred_console()")
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Link: https://lore.kernel.org/r/20240909075652.747370-1-liaoyu15@huawei.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-09 17:35:06 +02:00
John Ogness
daeed1595b printk: Avoid false positive lockdep report for legacy printing
Legacy console printing from printk() caller context may invoke
the console driver from atomic context. This leads to a lockdep
splat because the console driver will acquire a sleeping lock
and the caller may already hold a spinning lock. This is noticed
by lockdep on !PREEMPT_RT configurations because it will lead to
a problem on PREEMPT_RT.

However, on PREEMPT_RT the printing path from atomic context is
always avoided and the console driver is always invoked from a
dedicated thread. Thus the lockdep splat on !PREEMPT_RT is a
false positive.

For !PREEMPT_RT override the lock-context before invoking the
console driver to avoid the false positive.

Do not override the lock-context for PREEMPT_RT in order to
allow lockdep to catch any real locking context issues related
to the write callback usage.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-18-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:33 +02:00
John Ogness
1529bbb6e2 printk: nbcon: Assign nice -20 for printing threads
It is important that console printing threads are scheduled
shortly after a printk call and with generous runtime budgets.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-17-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:33 +02:00
John Ogness
5f53ca3ff8 printk: Implement legacy printer kthread for PREEMPT_RT
The write() callback of legacy consoles usually makes use of
spinlocks. This is not permitted with PREEMPT_RT in atomic
contexts.

For PREEMPT_RT, create a new kthread to handle printing of all
the legacy consoles (and nbcon consoles if boot consoles are
registered). This allows legacy consoles to work on PREEMPT_RT
without requiring modification. (However they will not have
the reliability properties guaranteed by nbcon atomic
consoles.)

Use the existing printk_kthreads_check_locked() to start/stop
the legacy kthread as needed.

Introduce the macro force_legacy_kthread() to query if the
forced threading of legacy consoles is in effect. Although
currently only enabled for PREEMPT_RT, this acts as a simple
mechanism for the future to allow other preemption models to
easily take advantage of the non-interference property provided
by the legacy kthread.

When force_legacy_kthread() is true, the legacy kthread
fulfills the role of the console_flush_type @legacy_offload by
waking the legacy kthread instead of printing via the
console_lock in the irq_work. If the legacy kthread is not
yet available, no legacy printing takes place (unless in
panic).

If for some reason the legacy kthread fails to create, any
legacy consoles are unregistered. With force_legacy_kthread(),
the legacy kthread is a critical component for legacy consoles.

These changes only affect CONFIG_PREEMPT_RT.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-16-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:33 +02:00
John Ogness
5102981d5e printk: nbcon: Show replay message on takeover
An emergency or panic context can takeover console ownership
while the current owner was printing a printk message. The
atomic printer will re-print the message that the previous
owner was printing. However, this can look confusing to the
user and may even seem as though a message was lost.

  [3430014.1
  [3430014.181123] usb 1-2: Product: USB Audio

Add a new field @nbcon_prev_seq to struct console to track
the sequence number to print that was assigned to the previous
console owner. If this matches the sequence number to print
that the current owner is assigned, then a takeover must have
occurred. In this case, print an additional message to inform
the user that the previous message is being printed again.

  [3430014.1
  ** replaying previous printk message **
  [3430014.181123] usb 1-2: Product: USB Audio

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-12-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:32 +02:00
John Ogness
75d430372a printk: Provide helper for message prepending
In order to support prepending different texts to printk
messages, split out the prepending code into a helper
function.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-11-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:32 +02:00
John Ogness
13189fa73a printk: nbcon: Rely on kthreads for normal operation
Once the kthread is running and available
(i.e. @printk_kthreads_running is set), the kthread becomes
responsible for flushing any pending messages which are added
in NBCON_PRIO_NORMAL context. Namely the legacy
console_flush_all() and device_release() no longer flush the
console. And nbcon_atomic_flush_pending() used by
nbcon_cpu_emergency_exit() no longer flushes messages added
after the emergency messages.

The console context is safe when used by the kthread only when
one of the following conditions are true:

  1. Other caller acquires the console context with
     NBCON_PRIO_NORMAL with preemption disabled. It will
     release the context before rescheduling.

  2. Other caller acquires the console context with
     NBCON_PRIO_NORMAL under the device_lock.

  3. The kthread is the only context which acquires the console
     with NBCON_PRIO_NORMAL.

This is satisfied for all atomic printing call sites:

nbcon_legacy_emit_next_record() (#1)

nbcon_atomic_flush_pending_con() (#1)

nbcon_device_release() (#2)

It is even double guaranteed when @printk_kthreads_running
is set because then _only_ the kthread will print for
NBCON_PRIO_NORMAL. (#3)

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-10-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:32 +02:00
John Ogness
5c586baa60 printk: nbcon: Use thread callback if in task context for legacy
When printing via console_lock, the write_atomic() callback is
used for nbcon consoles. However, if it is known that the
current context is a task context, the write_thread() callback
can be used instead.

Using write_thread() instead of write_atomic() helps to reduce
large disabled preemption regions when the device_lock does not
disable preemption.

This is mainly a preparatory change to allow avoiding
write_atomic() completely during normal operation if boot
consoles are registered.

As a side-effect, it also allows consolidating the printing
code for legacy printing and the kthread printer.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-9-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:32 +02:00
Thomas Gleixner
76f258bf3f printk: nbcon: Introduce printer kthreads
Provide the main implementation for running a printer kthread
per nbcon console that is takeover/handover aware. This
includes:

- new mandatory write_thread() callback
- kthread creation
- kthread main printing loop
- kthread wakeup mechanism
- kthread shutdown

kthread creation is a bit tricky because consoles may register
before kthreads can be created. In such cases, registration
will succeed, even though no kthread exists. Once kthreads can
be created, an early_initcall will set @printk_kthreads_ready.
If there are no registered boot consoles, the early_initcall
creates the kthreads for all registered nbcon consoles. If
kthread creation fails, the related console is unregistered.

If there are registered boot consoles when
@printk_kthreads_ready is set, no kthreads are created until
the final boot console unregisters.

Once kthread creation finally occurs, @printk_kthreads_running
is set so that the system knows kthreads are available for all
registered nbcon consoles.

If @printk_kthreads_running is already set when the console
is registering, the kthread is created during registration. If
kthread creation fails, the registration will fail.

Until @printk_kthreads_running is set, console printing occurs
directly via the console_lock.

kthread shutdown on system shutdown/reboot is necessary to
ensure the printer kthreads finish their printing so that the
system can cleanly transition back to direct printing via the
console_lock in order to reliably push out the final
shutdown/reboot messages. @printk_kthreads_running is cleared
before shutting down the individual kthreads.

The kthread uses a new mandatory write_thread() callback that
is called with both device_lock() and the console context
acquired.

The console ownership handling is necessary for synchronization
against write_atomic() which is synchronized only via the
console context ownership.

The device_lock() serializes acquiring the console context with
NBCON_PRIO_NORMAL. It is needed in case the device_lock() does
not disable preemption. It prevents the following race:

CPU0				CPU1

 [ task A ]

 nbcon_context_try_acquire()
   # success with NORMAL prio
   # .unsafe == false;  // safe for takeover

 [ schedule: task A -> B ]

				WARN_ON()
				  nbcon_atomic_flush_pending()
				    nbcon_context_try_acquire()
				      # success with EMERGENCY prio

				      # flushing
				      nbcon_context_release()

				      # HERE: con->nbcon_state is free
				      #       to take by anyone !!!

 nbcon_context_try_acquire()
   # success with NORMAL prio [ task B ]

 [ schedule: task B -> A ]

 nbcon_enter_unsafe()
   nbcon_context_can_proceed()

BUG: nbcon_context_can_proceed() returns "true" because
     the console is owned by a context on CPU0 with
     NBCON_PRIO_NORMAL.

     But it should return "false". The console is owned
     by a context from task B and we do the check
     in a context from task A.

Note that with these changes, the printer kthreads do not yet
take over full responsibility for nbcon printing during normal
operation. These changes only focus on the lifecycle of the
kthreads.

Co-developed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-7-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:32 +02:00
John Ogness
6cb58cfebb printk: nbcon: Add context to usable() and emit()
The nbcon consoles will have two callbacks to be used for
different contexts. In order to determine if an nbcon console
is usable, console_is_usable() must know if it is a context
that will need to use the optional write_atomic() callback.
Also, nbcon_emit_next_record() must know which callback it
needs to call.

Add an extra parameter @use_atomic to console_is_usable() and
nbcon_emit_next_record() to specify this.

Since so far only the write_atomic() callback exists,
@use_atomic is set to true for all call sites.

For legacy consoles, @use_atomic is not used.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-5-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:32 +02:00
John Ogness
0e53e2d9f7 printk: Flush console on unregister_console()
Ensure consoles have flushed pending records before
unregistering. The console should print up to at least its
related "console disabled" record.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-4-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:32 +02:00
John Ogness
e37577ebbf printk: Fail pr_flush() if before SYSTEM_SCHEDULING
A follow-up change adds pr_flush() to console unregistration.
However, with boot consoles unregistration can happen very
early if there are also regular consoles registering as well.
In this case the pr_flush() is not important because all
consoles are flushed when checking the initial console sequence
number.

Allow pr_flush() to fail if @system_state has not yet reached
SYSTEM_SCHEDULING. This avoids might_sleep() and msleep()
explosions that would otherwise occur:

[    0.436739][    T0] printk: legacy console [ttyS0] enabled
[    0.439820][    T0] printk: legacy bootconsole [earlyser0] disabled
[    0.446822][    T0] BUG: scheduling while atomic: swapper/0/0/0x00000002
[    0.450491][    T0] 1 lock held by swapper/0/0:
[    0.457897][    T0]  #0: ffffffff82ae5f88 (console_mutex){+.+.}-{4:4}, at: console_list_lock+0x20/0x70
[    0.463141][    T0] Modules linked in:
[    0.465307][    T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.10.0-rc1+ #372
[    0.469394][    T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
[    0.474402][    T0] Call Trace:
[    0.476246][    T0]  <TASK>
[    0.481473][    T0]  dump_stack_lvl+0x93/0xb0
[    0.483949][    T0]  dump_stack+0x10/0x20
[    0.486256][    T0]  __schedule_bug+0x68/0x90
[    0.488753][    T0]  __schedule+0xb9b/0xd80
[    0.491179][    T0]  ? lock_release+0xb5/0x270
[    0.493732][    T0]  schedule+0x43/0x170
[    0.495998][    T0]  schedule_timeout+0xc5/0x1e0
[    0.498634][    T0]  ? __pfx_process_timeout+0x10/0x10
[    0.501522][    T0]  ? msleep+0x13/0x50
[    0.503728][    T0]  msleep+0x3c/0x50
[    0.505847][    T0]  __pr_flush.constprop.0.isra.0+0x56/0x500
[    0.509050][    T0]  ? _printk+0x58/0x80
[    0.511332][    T0]  ? lock_is_held_type+0x9c/0x110
[    0.514106][    T0]  unregister_console_locked+0xe1/0x450
[    0.517144][    T0]  register_console+0x509/0x620
[    0.519827][    T0]  ? __pfx_univ8250_console_init+0x10/0x10
[    0.523042][    T0]  univ8250_console_init+0x24/0x40
[    0.525845][    T0]  console_init+0x43/0x210
[    0.528280][    T0]  start_kernel+0x493/0x980
[    0.530773][    T0]  x86_64_start_reservations+0x18/0x30
[    0.533755][    T0]  x86_64_start_kernel+0xae/0xc0
[    0.536473][    T0]  common_startup_64+0x12c/0x138
[    0.539210][    T0]  </TASK>

And then the kernel goes into an infinite loop complaining about:

1. releasing a pinned lock
2. unpinning an unpinned lock
3. bad: scheduling from the idle thread!
4. goto 1

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240904120536.115780-3-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-09-04 15:56:32 +02:00
Daniel Vetter
4461e9e5c3 Linux 6.11-rc5
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Merge v6.11-rc5 into drm-next

amdgpu pr conconflicts due to patches cherry-picked to -fixes, I might
as well catch up with a backmerge and handle them all. Plus both misc
and intel maintainers asked for a backmerge anyway.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2024-08-27 14:09:45 +02:00
John Ogness
6690d6b527 printk: Add helper for flush type logic
There are many call sites where console flushing occur.
Depending on the system state and types of consoles, the flush
methods to use are different. A flush call site generally must
consider:

	@have_boot_console
	@have_nbcon_console
	@have_legacy_console
	@legacy_allow_panic_sync
	is_printk_preferred()

and take into account the current CPU state:

	NBCON_PRIO_NORMAL
	NBCON_PRIO_EMERGENCY
	NBCON_PRIO_PANIC

in order to decide if it should:

	flush nbcon directly via atomic_write() callback
	flush legacy directly via console_unlock
	flush legacy via offload to irq_work

All of these call sites use their own logic to make this
decision, which is complicated and error prone. Especially
later when two more flush methods will be introduced:

	flush nbcon via offload to kthread
	flush legacy via offload to kthread

Introduce a new internal struct console_flush_type that specifies
which console flushing methods should be used in the context of
the caller.

Introduce a helper function to fill out console_flush_type to
be used for flushing call sites.

Replace the logic of all flushing call sites to use the new
helper.

This change standardizes behavior, leading to both fixes and
optimizations across various call sites. For instance, in
console_cpu_notify(), the new logic ensures that nbcon consoles
are flushed when they aren’t managed by the legacy loop.
Similarly, in console_flush_on_panic(), the system no longer
needs to flush nbcon consoles if none are present.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-31-john.ogness@linutronix.de
[pmladek@suse.com: Updated the commit message.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:49 +02:00
John Ogness
e35a888427 printk: Coordinate direct printing in panic
If legacy and nbcon consoles are registered and the nbcon
consoles are allowed to flush (i.e. no boot consoles
registered), the legacy consoles will no longer perform
direct printing on the panic CPU until after the backtrace
has been stored. This will give the safe nbcon consoles a
chance to print the panic messages before allowing the
unsafe legacy consoles to print.

If no nbcon consoles are registered or they are not allowed
to flush because boot consoles are registered, there is no
change in behavior (i.e. legacy consoles will always attempt
to print from the printk() caller context).

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-30-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:25 +02:00
John Ogness
bebd87ae27 printk: Track nbcon consoles
Add a global flag @have_nbcon_console to identify if any nbcon
consoles are registered. This will be used in follow-up commits
to preserve legacy behavior when no nbcon consoles are registered.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-29-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:25 +02:00
John Ogness
60013065fd printk: Avoid console_lock dance if no legacy or boot consoles
Currently the console lock is used to attempt legacy-type
printing even if there are no legacy or boot consoles registered.
If no such consoles are registered, the console lock does not
need to be taken.

Add tracking of legacy console registration and use it with
boot console tracking to avoid unnecessary code paths, i.e.
do not use the console lock if there are no boot consoles
and no legacy consoles.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-28-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:24 +02:00
John Ogness
d2e85ca7a7 printk: Flush nbcon consoles first on panic
In console_flush_on_panic(), flush the nbcon consoles before
flushing legacy consoles. The legacy write() callbacks are not
fully safe when oops_in_progress is set.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-26-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:24 +02:00
John Ogness
8ba77712a7 printk: nbcon: Flush new records on device_release()
There may be new records that were added while a driver was
holding the nbcon context for non-printing purposes. These
new records must be flushed by the nbcon_device_release()
context because no other context will do it.

If boot consoles are registered, the legacy loop is used
(either direct or per irq_work) to handle the flushing.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-25-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:24 +02:00
John Ogness
c158834b22 printk: nbcon: Use nbcon consoles in console_flush_all()
Allow nbcon consoles to print messages in the legacy printk()
caller context (printing via unlock) by integrating them into
console_flush_all(). The write_atomic() callback is used for
printing.

Provide nbcon_legacy_emit_next_record(), which acts as the
nbcon variant of console_emit_next_record(). Call this variant
within console_flush_all() for nbcon consoles. Since nbcon
consoles use their own @nbcon_seq variable to track the next
record to print, this also must be appropriately handled in
console_flush_all().

Note that the legacy printing logic uses @handover to detect
handovers for printing all consoles. For nbcon consoles,
handovers/takeovers occur on a per-console basis and thus do
not cause the console_flush_all() loop to abort.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-23-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:24 +02:00
John Ogness
97ea9bccfc printk: Track registered boot consoles
Unfortunately it is not known if a boot console and a regular
(legacy or nbcon) console use the same hardware. For this reason
they must not be allowed to print simultaneously.

For legacy consoles this is not an issue because they are
already synchronized with the boot consoles using the console
lock. However nbcon consoles can be triggered separately.

Add a global flag @have_boot_console to identify if any boot
consoles are registered. This will be used in follow-up commits
to ensure that boot consoles and nbcon consoles cannot print
simultaneously.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-22-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:24 +02:00
John Ogness
fc400d5f63 printk: Add @flags argument for console_is_usable()
The caller of console_is_usable() usually needs @console->flags
for its own checks. Rather than having console_is_usable() read
its own copy, make the caller pass in the @flags. This also
ensures that the caller saw the same @flags value.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-19-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:24 +02:00
John Ogness
864c25c83d printk: Make console_is_usable() available to nbcon.c
Move console_is_usable() as-is into internal.h so that it can
be used by nbcon printing functions as well.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-17-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:23 +02:00
John Ogness
e55c3bcf38 printk: nbcon: Use driver synchronization while (un)registering
Console drivers typically have to deal with access to the
hardware via user input/output (such as an interactive login
shell) and output of kernel messages via printk() calls.

They use some classic driver-specific locking mechanism in most
situations. But console->write_atomic() callbacks, used by nbcon
consoles, are synchronized only by acquiring the console
context.

The synchronization via the console context ownership is possible
only when the console driver is registered. It is when a
particular device driver is connected with a particular console
driver.

The two synchronization mechanisms must be synchronized between
each other. It is tricky because the console context ownership
is quite special. It might be taken over by a higher priority
context. Also CPU migration must be disabled. The most tricky
part is to (dis)connect these two mechanisms during the console
(un)registration.

Use the driver-specific locking callbacks: device_lock(),
device_unlock(). They allow taking the device-specific lock
while the device is being (un)registered by the related console
driver.

For example, these callbacks lock/unlock the port lock for
serial port drivers.

Note that the driver-specific locking is only needed during
(un)register if it is an nbcon console with the write_atomic()
callback implemented. If write_atomic() is not implemented, the
driver should never attempt to access the hardware without
first acquiring its driver-specific lock.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-10-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:23 +02:00
Petr Mladek
d3ff380d47 printk: Properly deal with nbcon consoles on seq init
If a non-boot console is registering and boot consoles exist,
the consoles are flushed before being unregistered. This allows
the non-boot console to continue where the boot console left
off.

If for whatever reason flushing fails, the lowest seq found from
any of the enabled boot consoles is used. Until now con->seq was
checked. However, if it is an nbcon boot console, the function
nbcon_seq_read() must be used to read seq because con->seq is
not updated for nbcon consoles.

Check if it is an nbcon boot console and if so call
nbcon_seq_read() to read seq.

Also, avoid usage of con->seq as temporary storage of the
starting record. Instead, rename console_init_seq() to
get_init_console_seq() and just return the value. For nbcon
consoles set the sequence via nbcon_seq_force(), for legacy
consoles set con->seq.

The cleaned design should make sure that the value stays and is
set before the console is added to the console list. It also
unifies the sequence number initialization for legacy and nbcon
consoles.

Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20240820063001.36405-4-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:22 +02:00
John Ogness
f37b105fae printk: nbcon: Consolidate alloc() and init()
Rather than splitting the nbcon allocation and initialization into
two pieces, perform all initialization in nbcon_alloc(). Later,
the initial sequence is calculated and can be explicitly set using
nbcon_seq_force(). This removes the need for the strong rules of
nbcon_init() that even included a BUG_ON().

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240820063001.36405-3-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:22 +02:00
John Ogness
eda25860bf printk: Add notation to console_srcu locking
kernel/printk/printk.c:284:5: sparse: sparse: context imbalance in
'console_srcu_read_lock' - wrong count at exit
include/linux/srcu.h:301:9: sparse: sparse: context imbalance in
'console_srcu_read_unlock' - unexpected unlock

Fixes: 6c4afa7914 ("printk: Prepare for SRCU console list protection")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240820063001.36405-2-john.ogness@linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-21 14:56:22 +02:00
Ryo Takakura
bcc954c6ca printk/panic: Allow cpu backtraces to be written into ringbuffer during panic
commit 779dbc2e78 ("printk: Avoid non-panic CPUs writing
to ringbuffer") disabled non-panic CPUs to further write messages to
ringbuffer after panicked.

Since the commit, non-panicked CPU's are not allowed to write to
ring buffer after panicked and CPU backtrace which is triggered
after panicked to sample non-panicked CPUs' backtrace no longer
serves its function as it has nothing to print.

Fix the issue by allowing non-panicked CPUs to write into ringbuffer
while CPU backtrace is in flight.

Fixes: 779dbc2e78 ("printk: Avoid non-panic CPUs writing to ringbuffer")
Signed-off-by: Ryo Takakura <takakura@valinux.co.jp>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240812072703.339690-1-takakura@valinux.co.jp
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-08-13 14:16:22 +02:00
Daniel Vetter
91dae758bd drm-misc-next for v6.12:
UAPI Changes:
 
 virtio:
 - Define DRM capset
 
 Cross-subsystem Changes:
 
 dma-buf:
 - heaps: Clean up documentation
 
 printk:
 - Pass description to kmsg_dump()
 
 Core Changes:
 
 CI:
 - Update IGT tests
 - Point upstream repo to GitLab instance
 
 modesetting:
 - Introduce Power Saving Policy property for connectors
 - Add might_fault() to drm_modeset_lock priming
 - Add dynamic per-crtc vblank configuration support
 
 panic:
 - Avoid build-time interference with framebuffer console
 
 docs:
 - Document Colorspace property
 
 scheduler:
 - Remove full_recover from drm_sched_start
 
 TTM:
 - Make LRU walk restartable after dropping locks
 - Allow direct reclaim to allocate local memory
 
 Driver Changes:
 
 amdgpu:
 - Support Power Saving Policy connector property
 
 ast:
 - astdp: Support AST2600 with VGA; Clean up HPD
 
 bridge:
 - Silence error message on -EPROBE_DEFER
 - analogix: Clean aup
 - bridge-connector: Fix double free
 - lt6505: Disable interrupt when powered off
 - tc358767: Make default DP port preemphasis configurable
 
 gma500:
 - Update i2c terminology
 
 ivpu:
 - Add MODULE_FIRMWARE()
 
 lcdif:
 - Fix pixel clock
 
 loongson:
 - Use GEM refcount over TTM's
 
 mgag200:
 - Improve BMC handling
 - Support VBLANK intterupts
 
 nouveau:
 - Refactor and clean up internals
 - Use GEM refcount over TTM's
 
 panel:
 - Shutdown fixes plus documentation
 - Refactor several drivers for better code sharing
 - boe-th101mb31ig002: Support for starry-er88577 MIPI-DSI panel plus
   DT; Fix porch parameter
 - edp: Support AOU B116XTN02.3, AUO B116XAN06.1, AOU B116XAT04.1,
   BOE NV140WUM-N41, BOE NV133WUM-N63, BOE NV116WHM-A4D, CMN N116BCA-EA2,
   CMN N116BCP-EA2, CSW MNB601LS1-4
 - himax-hx8394: Support Microchip AC40T08A MIPI Display panel plus DT
 - ilitek-ili9806e: Support Densitron DMT028VGHMCMI-1D TFT plus DT
 - jd9365da: Support Melfas lmfbx101117480 MIPI-DSI panel plus DT; Refactor
   for code sharing
 
 sti:
 - Fix module owner
 
 stm:
 - Avoid UAF wih managed plane and CRTC helpers
 - Fix module owner
 - Fix error handling in probe
 - Depend on COMMON_CLK
 - ltdc: Fix transparency after disabling plane; Remove unused interrupt
 
 tegra:
 - Call drm_atomic_helper_shutdown()
 
 v3d:
 - Clean up perfmon
 
 vkms:
 - Clean up
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Merge tag 'drm-misc-next-2024-08-01' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-next

drm-misc-next for v6.12:

UAPI Changes:

virtio:
- Define DRM capset

Cross-subsystem Changes:

dma-buf:
- heaps: Clean up documentation

printk:
- Pass description to kmsg_dump()

Core Changes:

CI:
- Update IGT tests
- Point upstream repo to GitLab instance

modesetting:
- Introduce Power Saving Policy property for connectors
- Add might_fault() to drm_modeset_lock priming
- Add dynamic per-crtc vblank configuration support

panic:
- Avoid build-time interference with framebuffer console

docs:
- Document Colorspace property

scheduler:
- Remove full_recover from drm_sched_start

TTM:
- Make LRU walk restartable after dropping locks
- Allow direct reclaim to allocate local memory

Driver Changes:

amdgpu:
- Support Power Saving Policy connector property

ast:
- astdp: Support AST2600 with VGA; Clean up HPD

bridge:
- Silence error message on -EPROBE_DEFER
- analogix: Clean aup
- bridge-connector: Fix double free
- lt6505: Disable interrupt when powered off
- tc358767: Make default DP port preemphasis configurable

gma500:
- Update i2c terminology

ivpu:
- Add MODULE_FIRMWARE()

lcdif:
- Fix pixel clock

loongson:
- Use GEM refcount over TTM's

mgag200:
- Improve BMC handling
- Support VBLANK intterupts

nouveau:
- Refactor and clean up internals
- Use GEM refcount over TTM's

panel:
- Shutdown fixes plus documentation
- Refactor several drivers for better code sharing
- boe-th101mb31ig002: Support for starry-er88577 MIPI-DSI panel plus
  DT; Fix porch parameter
- edp: Support AOU B116XTN02.3, AUO B116XAN06.1, AOU B116XAT04.1,
  BOE NV140WUM-N41, BOE NV133WUM-N63, BOE NV116WHM-A4D, CMN N116BCA-EA2,
  CMN N116BCP-EA2, CSW MNB601LS1-4
- himax-hx8394: Support Microchip AC40T08A MIPI Display panel plus DT
- ilitek-ili9806e: Support Densitron DMT028VGHMCMI-1D TFT plus DT
- jd9365da: Support Melfas lmfbx101117480 MIPI-DSI panel plus DT; Refactor
  for code sharing

sti:
- Fix module owner

stm:
- Avoid UAF wih managed plane and CRTC helpers
- Fix module owner
- Fix error handling in probe
- Depend on COMMON_CLK
- ltdc: Fix transparency after disabling plane; Remove unused interrupt

tegra:
- Call drm_atomic_helper_shutdown()

v3d:
- Clean up perfmon

vkms:
- Clean up

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240801121406.GA102996@linux.fritz.box
2024-08-08 18:58:46 +02:00
Thomas Zimmermann
0e8655b4e8 Merge drm/drm-next into drm-misc-next
Backmerging to get a late RC of v6.10 before moving into v6.11.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
2024-07-29 09:35:54 +02:00
Linus Torvalds
8bf100092d trivial printk changes for 6.11
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Merge tag 'printk-for-6.11-trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - trivial printk changes

The bigger "real" printk work is still being discussed.

* tag 'printk-for-6.11-trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  vsprintf: add missing MODULE_DESCRIPTION() macro
  printk: Rename console_replay_all() and update context
2024-07-25 13:18:41 -07:00
Joel Granados
78eb4ea25c sysctl: treewide: constify the ctl_table argument of proc_handlers
const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.

This patch has been generated by the following coccinelle script:

```
  virtual patch

  @r1@
  identifier ctl, write, buffer, lenp, ppos;
  identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

  @r2@
  identifier func, ctl, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int write, void *buffer, size_t *lenp, loff_t *ppos)
  { ... }

  @r3@
  identifier func;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int , void *, size_t *, loff_t *);

  @r4@
  identifier func, ctl;
  @@

  int func(
  - struct ctl_table *ctl
  + const struct ctl_table *ctl
    ,int , void *, size_t *, loff_t *);

  @r5@
  identifier func, write, buffer, lenp, ppos;
  @@

  int func(
  - struct ctl_table *
  + const struct ctl_table *
    ,int write, void *buffer, size_t *lenp, loff_t *ppos);

```

* Code formatting was adjusted in xfs_sysctl.c to comply with code
  conventions. The xfs_stats_clear_proc_handler,
  xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
  adjusted.

* The ctl_table argument in proc_watchdog_common was const qualified.
  This is called from a proc_handler itself and is calling back into
  another proc_handler, making it necessary to change it as part of the
  proc_handler migration.

Co-developed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Co-developed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-07-24 20:59:29 +02:00
Jocelyn Falempe
e1a261ba59 printk: Add a short description string to kmsg_dump()
kmsg_dump doesn't forward the panic reason string to the kmsg_dumper
callback.
This patch adds a new struct kmsg_dump_detail, that will hold the
reason and description, and pass it to the dump() callback.

To avoid updating all kmsg_dump() call, it adds a kmsg_dump_desc()
function and a macro for backward compatibility.

I've written this for drm_panic, but it can be useful for other
kmsg_dumper.
It allows to see the panic reason, like "sysrq triggered crash"
or "VFS: Unable to mount root fs on xxxx" on the drm panic screen.

v2:
 * Use a struct kmsg_dump_detail to hold the reason and description
   pointer, for more flexibility if we want to add other parameters.
   (Kees Cook)
 * Fix powerpc/nvram_64 build, as I didn't update the forward
   declaration of oops_to_nvram()

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Kees Cook <kees@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240702122639.248110-1-jfalempe@redhat.com
2024-07-17 12:35:24 +02:00
Tony Lindgren
7640f1a44e printk: Add match_devname_and_update_preferred_console()
Let's add match_devname_and_update_preferred_console() for driver
subsystems to call during init when the console is ready, and it's
character device name is known. For now, we use it only for the serial
layer to allow console=DEVNAME:0.0 style hardware based addressing for
consoles.

The earlier attempt on doing this caused a regression with the kernel
command line console order as it added calling __add_preferred_console()
again later on during init. A better approach was suggested by Petr where
we add the deferred console to the console_cmdline[] and update it later
on when the console is ready.

Suggested-by: Petr Mladek <pmladek@suse.com>
Co-developed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Tony Lindgren <tony.lindgren@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240703100615.118762-2-tony.lindgren@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-04 15:41:44 +02:00
Greg Kroah-Hartman
cc8d5a2f09 Revert "printk: Save console options for add_preferred_console_match()"
This reverts commit f03e8c1060.

Let's roll back all of the serial core and printk console changes that
went into 6.10-rc1 as there still are problems with them that need to be
sorted out.

Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1
Reported-by: Petr Mladek <pmladek@suse.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-25 07:58:10 +02:00
Greg Kroah-Hartman
64f9f010c6 Revert "printk: Don't try to parse DEVNAME:0.0 console options"
This reverts commit 8a831c584e.

Let's roll back all of the serial core and printk console changes that
went into 6.10-rc1 as there still are problems with them that need to be
sorted out.

Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1
Reported-by: Petr Mladek <pmladek@suse.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-25 07:58:07 +02:00
Greg Kroah-Hartman
deb091cb05 Revert "printk: Flag register_console() if console is set on command line"
This reverts commit b73c9cbe4f.

Let's roll back all of the serial core and printk console changes that
went into 6.10-rc1 as there still are problems with them that need to be
sorted out.

Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1
Reported-by: Petr Mladek <pmladek@suse.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-25 07:58:03 +02:00
Sreenath Vijayan
3d9a0a2533 printk: Rename console_replay_all() and update context
Rename console_replay_all() to console_try_replay_all() to make
clear that the implementation is best effort. Also, the function
should not be called in NMI context as it takes locks, so update
the comment in code.

Fixes: 693f75b91a ("printk: Add function to replay kernel log on consoles")
Fixes: 1b743485e2 ("tty/sysrq: Replay kernel log messages on consoles via sysrq")
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Shimoyashiki Taichi <taichi.shimoyashiki@sony.com>
Signed-off-by: Sreenath Vijayan <sreenath.vijayan@sony.com>
Link: https://lore.kernel.org/r/Zlguq/wU21Z8MqI4@sreenath.vijayan@sony.com
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-06-03 17:17:29 +02:00
Linus Torvalds
f6b8e86b7a TTY/Serial changes for 6.10-rc1
Here is the big set of tty/serial driver changes for 6.10-rc1.  Included
 in here are:
   - Usual good set of api cleanups and evolution by Jiri Slaby to make
     the serial interfaces move out of the 1990's by using kfifos instead
     of hand-rolling their own logic.
   - 8250_exar driver updates
   - max3100 driver updates
   - sc16is7xx driver updates
   - exar driver updates
   - sh-sci driver updates
   - tty ldisc api addition to help refuse bindings
   - other smaller serial driver updates
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty / serial updates from Greg KH:
 "Here is the big set of tty/serial driver changes for 6.10-rc1.
  Included in here are:

   - Usual good set of api cleanups and evolution by Jiri Slaby to make
     the serial interfaces move out of the 1990's by using kfifos
     instead of hand-rolling their own logic.

   - 8250_exar driver updates

   - max3100 driver updates

   - sc16is7xx driver updates

   - exar driver updates

   - sh-sci driver updates

   - tty ldisc api addition to help refuse bindings

   - other smaller serial driver updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (113 commits)
  serial: Clear UPF_DEAD before calling tty_port_register_device_attr_serdev()
  serial: imx: Raise TX trigger level to 8
  serial: 8250_pnp: Simplify "line" related code
  serial: sh-sci: simplify locking when re-issuing RXDMA fails
  serial: sh-sci: let timeout timer only run when DMA is scheduled
  serial: sh-sci: describe locking requirements for invalidating RXDMA
  serial: sh-sci: protect invalidating RXDMA on shutdown
  tty: add the option to have a tty reject a new ldisc
  serial: core: Call device_set_awake_path() for console port
  dt-bindings: serial: brcm,bcm2835-aux-uart: convert to dtschema
  tty: serial: uartps: Add support for uartps controller reset
  arm64: zynqmp: Add resets property for UART nodes
  dt-bindings: serial: cdns,uart: Add optional reset property
  serial: 8250_pnp: Switch to DEFINE_SIMPLE_DEV_PM_OPS()
  serial: 8250_exar: Keep the includes sorted
  serial: 8250_exar: Make type of bit the same in exar_ee_*_bit()
  serial: 8250_exar: Use BIT() in exar_ee_read()
  serial: 8250_exar: Switch to use dev_err_probe()
  serial: 8250_exar: Return directly from switch-cases
  serial: 8250_exar: Decrease indentation level
  ...
2024-05-22 11:53:02 -07:00
Linus Torvalds
a19264d086 printk changes for 6.10
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Merge tag 'printk-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Use no_printk() instead of "if (0) printk()" constructs to avoid
   generating printk index for messages disabled at compile time

 - Remove deprecated strncpy/strcpy from printk.c

 - Remove redundant CONFIG_BASE_FULL in favor of CONFIG_BASE_SMALL

* tag 'printk-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: cleanup deprecated uses of strncpy/strcpy
  printk: Remove redundant CONFIG_BASE_FULL
  printk: Change type of CONFIG_BASE_SMALL to bool
  printk: Fix LOG_CPU_MAX_BUF_SHIFT when BASE_SMALL is enabled
  ceph: Use no_printk() helper
  dyndbg: Use *no_printk() helpers
  dev_printk: Add and use dev_no_printk()
  printk: Let no_printk() use _printk()
2024-05-15 12:34:46 -07:00
Justin Stitt
e0550222e0 printk: cleanup deprecated uses of strncpy/strcpy
Cleanup some deprecated uses of strncpy() and strcpy() [1].

There doesn't seem to be any bugs with the current code but the
readability of this code could benefit from a quick makeover while
removing some deprecated stuff as a benefit.

The most interesting replacement made in this patch involves
concatenating "ttyS" with a digit-led user-supplied string. Instead of
doing two distinct string copies with carefully managed offsets and
lengths, let's use the more robust and self-explanatory scnprintf().
scnprintf will 1) respect the bounds of @buf, 2) null-terminate @buf, 3)
do the concatenation. This allows us to drop the manual NUL-byte assignment.

Also, since isdigit() is used about a dozen lines after the open-coded
version we'll replace it for uniformity's sake.

All the strcpy() --> strscpy() replacements are trivial as the source
strings are literals and much smaller than the destination size. No
behavioral change here.

Use the new 2-argument version of strscpy() introduced in Commit
e6584c3964 ("string: Allow 2-argument strscpy()"). However, to make
this work fully (since the size must be known at compile time), also
update the extern-qualified declaration to have the proper size
information.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90 [2]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [3]
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240429-strncpy-kernel-printk-printk-c-v1-1-4da7926d7b69@google.com
[pmladek@suse.com: Removed obsolete brackets and added empty lines.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-05-07 10:41:51 +02:00
Sreenath Vijayan
693f75b91a printk: Add function to replay kernel log on consoles
Add a generic function console_replay_all() for replaying
the kernel log on consoles, in any context. It would allow
viewing the logs on an unresponsive terminal via sysrq.

Reuse the existing code from console_flush_on_panic() for
resetting the sequence numbers, by introducing a new helper
function __console_rewind_all(). It is safe to be called
under console_lock().

Try to acquire lock on the console subsystem without waiting.
If successful, reset the sequence number to oldest available
record on all consoles and call console_unlock() which will
automatically flush the messages to the consoles.

Suggested-by: John Ogness <john.ogness@linutronix.de>
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Shimoyashiki Taichi <taichi.shimoyashiki@sony.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Sreenath Vijayan <sreenath.vijayan@sony.com>
Link: https://lore.kernel.org/r/90ee131c643a5033d117b556c0792de65129d4c3.1710220326.git.sreenath.vijayan@sony.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-11 14:22:52 +02:00
Tony Lindgren
b73c9cbe4f printk: Flag register_console() if console is set on command line
If add_preferred_console() is not called early in setup_console(), we can
end up having register_console() call try_enable_default_console() before a
console device has called add_preferred_console().

Let's set console_set_on_cmdline flag in console_setup() to prevent this
from happening.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20240327110021.59793-4-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09 15:30:13 +02:00
Tony Lindgren
8a831c584e printk: Don't try to parse DEVNAME:0.0 console options
Currently console_setup() tries to make a console index out of any digits
passed in the kernel command line for console. In the DEVNAME:0.0 case,
the name can contain a device IO address, so bail out on console names
with a ':'.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20240327110021.59793-3-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09 15:30:13 +02:00
Tony Lindgren
f03e8c1060 printk: Save console options for add_preferred_console_match()
Driver subsystems may need to translate the preferred console name to the
character device name used. We already do some of this in console_setup()
with a few hardcoded names, but that does not scale well.

The console options are parsed early in console_setup(), and the consoles
are added with __add_preferred_console(). At this point we don't know much
about the character device names and device drivers getting probed.

To allow driver subsystems to set up a preferred console, let's save the
kernel command line console options. To add a preferred console from a
driver subsystem with optional character device name translation, let's
add a new function add_preferred_console_match().

This allows the serial core layer to support console=DEVNAME:0.0 style
hardware based addressing in addition to the current console=ttyS0 style
naming. And we can start moving console_setup() character device parsing
to the driver subsystem specific code.

We use a separate array from the console_cmdline array as the character
device name and index may be unknown at the console_setup() time. And
eventually there's no need to call __add_preferred_console() until the
subsystem is ready to handle the console.

Adding the console name in addition to the character device name, and a
flag for an added console, could be added to the struct console_cmdline.
And the console_cmdline array handling could be modified accordingly. But
that complicates things compared saving the console options, and then
adding the consoles when the subsystems handling the consoles are ready.

Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240327110021.59793-2-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09 15:30:13 +02:00
Linus Torvalds
7033999ecd printk changes for 6.9-rc2
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Merge tag 'printk-for-6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fix from Petr Mladek:

 - Prevent scheduling in an atomic context when printk() takes over the
   console flushing duty

* tag 'printk-for-6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: Update @console_may_schedule in console_trylock_spinning()
2024-03-26 09:25:57 -07:00
Linus Torvalds
3bcb0bf65c TTY/Serial driver update for 6.9-rc1
Here is the big set of TTY/Serial driver updates and cleanups for
 6.9-rc1.  Included in here are:
   - more tty cleanups from Jiri
   - loads of 8250 driver cleanups from Andy
   - max310x driver updates
   - samsung serial driver updates
   - uart_prepare_sysrq_char() updates for many drivers
   - platform driver remove callback void cleanups
   - stm32 driver updates
   - other small tty/serial driver updates
 
 All of these have been in linux-next for a long time with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty / serial driver updates from Greg KH:
 "Here is the big set of TTY/Serial driver updates and cleanups for
  6.9-rc1. Included in here are:

   - more tty cleanups from Jiri

   - loads of 8250 driver cleanups from Andy

   - max310x driver updates

   - samsung serial driver updates

   - uart_prepare_sysrq_char() updates for many drivers

   - platform driver remove callback void cleanups

   - stm32 driver updates

   - other small tty/serial driver updates

  All of these have been in linux-next for a long time with no reported
  issues"

* tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
  dt-bindings: serial: stm32: add power-domains property
  serial: 8250_dw: Replace ACPI device check by a quirk
  serial: Lock console when calling into driver before registration
  serial: 8250_uniphier: Switch to use uart_read_port_properties()
  serial: 8250_tegra: Switch to use uart_read_port_properties()
  serial: 8250_pxa: Switch to use uart_read_port_properties()
  serial: 8250_omap: Switch to use uart_read_port_properties()
  serial: 8250_of: Switch to use uart_read_port_properties()
  serial: 8250_lpc18xx: Switch to use uart_read_port_properties()
  serial: 8250_ingenic: Switch to use uart_read_port_properties()
  serial: 8250_dw: Switch to use uart_read_port_properties()
  serial: 8250_bcm7271: Switch to use uart_read_port_properties()
  serial: 8250_bcm2835aux: Switch to use uart_read_port_properties()
  serial: 8250_aspeed_vuart: Switch to use uart_read_port_properties()
  serial: port: Introduce a common helper to read properties
  serial: core: Add UPIO_UNKNOWN constant for unknown port type
  serial: core: Move struct uart_port::quirks closer to possible values
  serial: sh-sci: Call sci_serial_{in,out}() directly
  serial: core: only stop transmit when HW fifo is empty
  serial: pch: Use uart_prepare_sysrq_char().
  ...
2024-03-21 12:44:10 -07:00
John Ogness
8076972468 printk: Update @console_may_schedule in console_trylock_spinning()
console_trylock_spinning() may takeover the console lock from a
schedulable context. Update @console_may_schedule to make sure it
reflects a trylock acquire.

Reported-by: Mukesh Ojha <quic_mojha@quicinc.com>
Closes: https://lore.kernel.org/lkml/20240222090538.23017-1-quic_mojha@quicinc.com
Fixes: dbdda842fe ("printk: Add console owner and waiter logic to load balance console writes")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/875xybmo2z.fsf@jogness.linutronix.de
Signed-off-by: Petr Mladek <pmladek@suse.com>
2024-03-15 17:03:32 +01:00