Commit Graph

712 Commits

Author SHA1 Message Date
Linus Torvalds aefcf2f4b5 Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull kernel lockdown mode from James Morris:
 "This is the latest iteration of the kernel lockdown patchset, from
  Matthew Garrett, David Howells and others.

  From the original description:

    This patchset introduces an optional kernel lockdown feature,
    intended to strengthen the boundary between UID 0 and the kernel.
    When enabled, various pieces of kernel functionality are restricted.
    Applications that rely on low-level access to either hardware or the
    kernel may cease working as a result - therefore this should not be
    enabled without appropriate evaluation beforehand.

    The majority of mainstream distributions have been carrying variants
    of this patchset for many years now, so there's value in providing a
    doesn't meet every distribution requirement, but gets us much closer
    to not requiring external patches.

  There are two major changes since this was last proposed for mainline:

   - Separating lockdown from EFI secure boot. Background discussion is
     covered here: https://lwn.net/Articles/751061/

   -  Implementation as an LSM, with a default stackable lockdown LSM
      module. This allows the lockdown feature to be policy-driven,
      rather than encoding an implicit policy within the mechanism.

  The new locked_down LSM hook is provided to allow LSMs to make a
  policy decision around whether kernel functionality that would allow
  tampering with or examining the runtime state of the kernel should be
  permitted.

  The included lockdown LSM provides an implementation with a simple
  policy intended for general purpose use. This policy provides a coarse
  level of granularity, controllable via the kernel command line:

    lockdown={integrity|confidentiality}

  Enable the kernel lockdown feature. If set to integrity, kernel features
  that allow userland to modify the running kernel are disabled. If set to
  confidentiality, kernel features that allow userland to extract
  confidential information from the kernel are also disabled.

  This may also be controlled via /sys/kernel/security/lockdown and
  overriden by kernel configuration.

  New or existing LSMs may implement finer-grained controls of the
  lockdown features. Refer to the lockdown_reason documentation in
  include/linux/security.h for details.

  The lockdown feature has had signficant design feedback and review
  across many subsystems. This code has been in linux-next for some
  weeks, with a few fixes applied along the way.

  Stephen Rothwell noted that commit 9d1f8be5cf ("bpf: Restrict bpf
  when kernel lockdown is in confidentiality mode") is missing a
  Signed-off-by from its author. Matthew responded that he is providing
  this under category (c) of the DCO"

* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
  kexec: Fix file verification on S390
  security: constify some arrays in lockdown LSM
  lockdown: Print current->comm in restriction messages
  efi: Restrict efivar_ssdt_load when the kernel is locked down
  tracefs: Restrict tracefs when the kernel is locked down
  debugfs: Restrict debugfs when the kernel is locked down
  kexec: Allow kexec_file() with appropriate IMA policy when locked down
  lockdown: Lock down perf when in confidentiality mode
  bpf: Restrict bpf when kernel lockdown is in confidentiality mode
  lockdown: Lock down tracing and perf kprobes when in confidentiality mode
  lockdown: Lock down /proc/kcore
  x86/mmiotrace: Lock down the testmmiotrace module
  lockdown: Lock down module params that specify hardware parameters (eg. ioport)
  lockdown: Lock down TIOCSSERIAL
  lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
  acpi: Disable ACPI table override if the kernel is locked down
  acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
  ACPI: Limit access to custom_method when the kernel is locked down
  x86/msr: Restrict MSR access when the kernel is locked down
  x86: Lock down IO port access when the kernel is locked down
  ...
2019-09-28 08:14:15 -07:00
Linus Torvalds 9c9fa97a8e Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - a few hot fixes

 - ocfs2 updates

 - almost all of -mm (slab-generic, slab, slub, kmemleak, kasan,
   cleanups, debug, pagecache, memcg, gup, pagemap, memory-hotplug,
   sparsemem, vmalloc, initialization, z3fold, compaction, mempolicy,
   oom-kill, hugetlb, migration, thp, mmap, madvise, shmem, zswap,
   zsmalloc)

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (132 commits)
  mm/zsmalloc.c: fix a -Wunused-function warning
  zswap: do not map same object twice
  zswap: use movable memory if zpool support allocate movable memory
  zpool: add malloc_support_movable to zpool_driver
  shmem: fix obsolete comment in shmem_getpage_gfp()
  mm/madvise: reduce code duplication in error handling paths
  mm: mmap: increase sockets maximum memory size pgoff for 32bits
  mm/mmap.c: refine find_vma_prev() with rb_last()
  riscv: make mmap allocation top-down by default
  mips: use generic mmap top-down layout and brk randomization
  mips: replace arch specific way to determine 32bit task with generic version
  mips: adjust brk randomization offset to fit generic version
  mips: use STACK_TOP when computing mmap base address
  mips: properly account for stack randomization and stack guard gap
  arm: use generic mmap top-down layout and brk randomization
  arm: use STACK_TOP when computing mmap base address
  arm: properly account for stack randomization and stack guard gap
  arm64, mm: make randomization selected by generic topdown mmap layout
  arm64, mm: move generic mmap layout functions to mm
  arm64: consider stack randomization for mmap base only when necessary
  ...
2019-09-24 16:10:23 -07:00
Michal Hocko 0158115f70 memcg, kmem: deprecate kmem.limit_in_bytes
Cgroup v1 memcg controller has exposed a dedicated kmem limit to users
which turned out to be really a bad idea because there are paths which
cannot shrink the kernel memory usage enough to get below the limit (e.g.
because the accounted memory is not reclaimable).  There are cases when
the failure is even not allowed (e.g.  __GFP_NOFAIL).  This means that the
kmem limit is in excess to the hard limit without any way to shrink and
thus completely useless.  OOM killer cannot be invoked to handle the
situation because that would lead to a premature oom killing.

As a result many places might see ENOMEM returning from kmalloc and result
in unexpected errors.  E.g.  a global OOM killer when there is a lot of
free memory because ENOMEM is translated into VM_FAULT_OOM in #PF path and
therefore pagefault_out_of_memory would result in OOM killer.

Please note that the kernel memory is still accounted to the overall limit
along with the user memory so removing the kmem specific limit should
still allow to contain kernel memory consumption.  Unlike the kmem one,
though, it invokes memory reclaim and targeted memcg oom killing if
necessary.

Start the deprecation process by crying to the kernel log.  Let's see
whether there are relevant usecases and simply return to EINVAL in the
second stage if nobody complains in few releases.

[akpm@linux-foundation.org: tweak documentation text]
Link: http://lkml.kernel.org/r/20190911151612.GI4023@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Thomas Lindroth <thomas.lindroth@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:10 -07:00
Vlastimil Babka 8974558f49 mm, page_owner, debug_pagealloc: save and dump freeing stack trace
The debug_pagealloc functionality is useful to catch buggy page allocator
users that cause e.g.  use after free or double free.  When page
inconsistency is detected, debugging is often simpler by knowing the call
stack of process that last allocated and freed the page.  When page_owner
is also enabled, we record the allocation stack trace, but not freeing.

This patch therefore adds recording of freeing process stack trace to page
owner info, if both page_owner and debug_pagealloc are configured and
enabled.  With only page_owner enabled, this info is not useful for the
memory leak debugging use case.  dump_page() is adjusted to print the
info.  An example result of calling __free_pages() twice may look like
this (note the page last free stack trace):

BUG: Bad page state in process bash  pfn:13d8f8
page:ffffc31984f63e00 refcount:-1 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x1affff800000000()
raw: 01affff800000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 ffffffffffffffff 0000000000000000
page dumped because: nonzero _refcount
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL)
 prep_new_page+0x143/0x150
 get_page_from_freelist+0x289/0x380
 __alloc_pages_nodemask+0x13c/0x2d0
 khugepaged+0x6e/0xc10
 kthread+0xf9/0x130
 ret_from_fork+0x3a/0x50
page last free stack trace:
 free_pcp_prepare+0x134/0x1e0
 free_unref_page+0x18/0x90
 khugepaged+0x7b/0xc10
 kthread+0xf9/0x130
 ret_from_fork+0x3a/0x50
Modules linked in:
CPU: 3 PID: 271 Comm: bash Not tainted 5.3.0-rc4-2.g07a1a73-default+ #57
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
Call Trace:
 dump_stack+0x85/0xc0
 bad_page.cold+0xba/0xbf
 rmqueue_pcplist.isra.0+0x6c5/0x6d0
 rmqueue+0x2d/0x810
 get_page_from_freelist+0x191/0x380
 __alloc_pages_nodemask+0x13c/0x2d0
 __get_free_pages+0xd/0x30
 __pud_alloc+0x2c/0x110
 copy_page_range+0x4f9/0x630
 dup_mmap+0x362/0x480
 dup_mm+0x68/0x110
 copy_process+0x19e1/0x1b40
 _do_fork+0x73/0x310
 __x64_sys_clone+0x75/0x80
 do_syscall_64+0x6e/0x1e0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f10af854a10
...

Link: http://lkml.kernel.org/r/20190820131828.22684-5-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:08 -07:00
Linus Torvalds 299d14d4c3 Merge tag 'pci-v5.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
 "Enumeration:

   - Consolidate _HPP/_HPX stuff in pci-acpi.c and simplify it
     (Krzysztof Wilczynski)

   - Fix incorrect PCIe device types and remove dev->has_secondary_link
     to simplify code that deals with upstream/downstream ports (Mika
     Westerberg)

   - After suspend, restore Resizable BAR size bits correctly for 1MB
     BARs (Sumit Saxena)

   - Enable PCI_MSI_IRQ_DOMAIN support for RISC-V (Wesley Terpstra)

  Virtualization:

   - Add ACS quirks for iProc PAXB (Abhinav Ratna), Amazon Annapurna
     Labs (Ali Saidi)

   - Move sysfs SR-IOV functions to iov.c (Kelsey Skunberg)

   - Remove group write permissions from sysfs sriov_numvfs,
     sriov_drivers_autoprobe (Kelsey Skunberg)

  Hotplug:

   - Simplify pciehp indicator control (Denis Efremov)

  Peer-to-peer DMA:

   - Allow P2P DMA between root ports for whitelisted bridges (Logan
     Gunthorpe)

   - Whitelist some Intel host bridges for P2P DMA (Logan Gunthorpe)

   - DMA map P2P DMA requests that traverse host bridge (Logan
     Gunthorpe)

  Amazon Annapurna Labs host bridge driver:

   - Add DT binding and controller driver (Jonathan Chocron)

  Hyper-V host bridge driver:

   - Fix hv_pci_dev->pci_slot use-after-free (Dexuan Cui)

   - Fix PCI domain number collisions (Haiyang Zhang)

   - Use instance ID bytes 4 & 5 as PCI domain numbers (Haiyang Zhang)

   - Fix build errors on non-SYSFS config (Randy Dunlap)

  i.MX6 host bridge driver:

   - Limit DBI register length (Stefan Agner)

  Intel VMD host bridge driver:

   - Fix config addressing issues (Jon Derrick)

  Layerscape host bridge driver:

   - Add bar_fixed_64bit property to endpoint driver (Xiaowei Bao)

   - Add CONFIG_PCI_LAYERSCAPE_EP to build EP/RC drivers separately
     (Xiaowei Bao)

  Mediatek host bridge driver:

   - Add MT7629 controller support (Jianjun Wang)

  Mobiveil host bridge driver:

   - Fix CPU base address setup (Hou Zhiqiang)

   - Make "num-lanes" property optional (Hou Zhiqiang)

  Tegra host bridge driver:

   - Fix OF node reference leak (Nishka Dasgupta)

   - Disable MSI for root ports to work around design problem (Vidya
     Sagar)

   - Add Tegra194 DT binding and controller support (Vidya Sagar)

   - Add support for sideband pins and slot regulators (Vidya Sagar)

   - Add PIPE2UPHY support (Vidya Sagar)

  Misc:

   - Remove unused pci_block_cfg_access() et al (Kelsey Skunberg)

   - Unexport pci_bus_get(), etc (Kelsey Skunberg)

   - Hide PM, VC, link speed, ATS, ECRC, PTM constants and interfaces in
     the PCI core (Kelsey Skunberg)

   - Clean up sysfs DEVICE_ATTR() usage (Kelsey Skunberg)

   - Mark expected switch fall-through (Gustavo A. R. Silva)

   - Propagate errors for optional regulators and PHYs (Thierry Reding)

   - Fix kernel command line resource_alignment parameter issues (Logan
     Gunthorpe)"

* tag 'pci-v5.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (112 commits)
  PCI: Add pci_irq_vector() and other stubs when !CONFIG_PCI
  arm64: tegra: Add PCIe slot supply information in p2972-0000 platform
  arm64: tegra: Add configuration for PCIe C5 sideband signals
  PCI: tegra: Add support to enable slot regulators
  PCI: tegra: Add support to configure sideband pins
  PCI: vmd: Fix shadow offsets to reflect spec changes
  PCI: vmd: Fix config addressing when using bus offsets
  PCI: dwc: Add validation that PCIe core is set to correct mode
  PCI: dwc: al: Add Amazon Annapurna Labs PCIe controller driver
  dt-bindings: PCI: Add Amazon's Annapurna Labs PCIe host bridge binding
  PCI: Add quirk to disable MSI-X support for Amazon's Annapurna Labs Root Port
  PCI/VPD: Prevent VPD access for Amazon's Annapurna Labs Root Port
  PCI: Add ACS quirk for Amazon Annapurna Labs root ports
  PCI: Add Amazon's Annapurna Labs vendor ID
  MAINTAINERS: Add PCI native host/endpoint controllers designated reviewer
  PCI: hv: Use bytes 4 and 5 from instance ID as the PCI domain numbers
  dt-bindings: PCI: tegra: Add PCIe slot supplies regulator entries
  dt-bindings: PCI: tegra: Add sideband pins configuration entries
  PCI: tegra: Add Tegra194 PCIe support
  PCI: Get rid of dev->has_secondary_link flag
  ...
2019-09-23 19:16:01 -07:00
Linus Torvalds 3e414b5bd2 Merge tag 'for-5.4/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:

 - crypto and DM crypt advances that allow the crypto API to reclaim
   implementation details that do not belong in DM crypt. The wrapper
   template for ESSIV generation that was factored out will also be used
   by fscrypt in the future.

 - Add root hash pkcs#7 signature verification to the DM verity target.

 - Add a new "clone" DM target that allows for efficient remote
   replication of a device.

 - Enhance DM bufio's cache to be tailored to each client based on use.
   Clients that make heavy use of the cache get more of it, and those
   that use less have reduced cache usage.

 - Add a new DM_GET_TARGET_VERSION ioctl to allow userspace to query the
   version number of a DM target (even if the associated module isn't
   yet loaded).

 - Fix invalid memory access in DM zoned target.

 - Fix the max_discard_sectors limit advertised by the DM raid target;
   it was mistakenly storing the limit in bytes rather than sectors.

 - Small optimizations and cleanups in DM writecache target.

 - Various fixes and cleanups in DM core, DM raid1 and space map portion
   of DM persistent data library.

* tag 'for-5.4/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (22 commits)
  dm: introduce DM_GET_TARGET_VERSION
  dm bufio: introduce a global cache replacement
  dm bufio: remove old-style buffer cleanup
  dm bufio: introduce a global queue
  dm bufio: refactor adjust_total_allocated
  dm bufio: call adjust_total_allocated from __link_buffer and __unlink_buffer
  dm: add clone target
  dm raid: fix updating of max_discard_sectors limit
  dm writecache: skip writecache_wait for pmem mode
  dm stats: use struct_size() helper
  dm crypt: omit parsing of the encapsulated cipher
  dm crypt: switch to ESSIV crypto API template
  crypto: essiv - create wrapper template for ESSIV generation
  dm space map common: remove check for impossible sm_find_free() return value
  dm raid1: use struct_size() with kzalloc()
  dm writecache: optimize performance by sorting the blocks for writeback_all
  dm writecache: add unlikely for getting two block with same LBA
  dm writecache: remove unused member pointer in writeback_struct
  dm zoned: fix invalid memory access
  dm verity: add root hash pkcs#7 signature verification
  ...
2019-09-21 10:40:37 -07:00
Linus Torvalds 45824fc0da Merge tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
 "This is a bit late, partly due to me travelling, and partly due to a
  power outage knocking out some of my test systems *while* I was
  travelling.

   - Initial support for running on a system with an Ultravisor, which
     is software that runs below the hypervisor and protects guests
     against some attacks by the hypervisor.

   - Support for building the kernel to run as a "Secure Virtual
     Machine", ie. as a guest capable of running on a system with an
     Ultravisor.

   - Some changes to our DMA code on bare metal, to allow devices with
     medium sized DMA masks (> 32 && < 59 bits) to use more than 2GB of
     DMA space.

   - Support for firmware assisted crash dumps on bare metal (powernv).

   - Two series fixing bugs in and refactoring our PCI EEH code.

   - A large series refactoring our exception entry code to use gas
     macros, both to make it more readable and also enable some future
     optimisations.

  As well as many cleanups and other minor features & fixups.

  Thanks to: Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew
  Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman Khandual,
  Balbir Singh, Benjamin Herrenschmidt, Cédric Le Goater, Christophe
  JAILLET, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig,
  Claudio Carvalho, Daniel Axtens, David Gibson, David Hildenbrand,
  Desnes A. Nunes do Rosario, Ganesh Goudar, Gautham R. Shenoy, Greg
  Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari Bathini, Joakim
  Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras, Lianbo
  Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar,
  Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan
  Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver
  O'Halloran, Qian Cai, Ram Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm,
  Sam Bobroff, Santosh Sivaraj, Segher Boessenkool, Sukadev Bhattiprolu,
  Thiago Bauermann, Thiago Jung Bauermann, Thomas Gleixner, Tom
  Lendacky, Vasant Hegde"

* tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (264 commits)
  powerpc/mm/mce: Keep irqs disabled during lockless page table walk
  powerpc: Use ftrace_graph_ret_addr() when unwinding
  powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
  ftrace: Look up the address of return_to_handler() using helpers
  powerpc: dump kernel log before carrying out fadump or kdump
  docs: powerpc: Add missing documentation reference
  powerpc/xmon: Fix output of XIVE IPI
  powerpc/xmon: Improve output of XIVE interrupts
  powerpc/mm/radix: remove useless kernel messages
  powerpc/fadump: support holes in kernel boot memory area
  powerpc/fadump: remove RMA_START and RMA_END macros
  powerpc/fadump: update documentation about option to release opalcore
  powerpc/fadump: consider f/w load area
  powerpc/opalcore: provide an option to invalidate /sys/firmware/opal/core file
  powerpc/opalcore: export /sys/firmware/opal/core for analysing opal crashes
  powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP
  powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel
  powerpc/fadump: improve how crashed kernel's memory is reserved
  powerpc/fadump: consider reserved ranges while releasing memory
  powerpc/fadump: make crash memory ranges array allocation generic
  ...
2019-09-20 11:48:06 -07:00
Linus Torvalds e444d51b14 Merge tag 'tty-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
 "Even in this age, people are still making new serial port silicon,
  why...

  Anyway, here's the TTY and Serial driver update for 5.4-rc1. Lots of
  changes in here for a number of embedded serial port devices that are
  being worked on because people really like to see those console
  logs...

  Other than that, nothing major here, no core tty changes that anyone
  should care about.

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

* tag 'tty-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (125 commits)
  serial: tegra: Add PIO mode support
  serial: tegra: report clk rate errors
  serial: tegra: add support to adjust baud rate
  serial: tegra: DT for Adjusted baud rates
  serial: tegra: add support to use 8 bytes trigger
  serial: tegra: set maximum num of uart ports to 8
  serial: tegra: check for FIFO mode enabled status
  dt-binding: serial: tegra: add new chips
  serial: tegra: report error to upper tty layer
  serial: tegra: flush the RX fifo on frame error
  serial: tegra: avoid reg access when clk disabled
  serial: tegra: add support to ignore read
  serial: sprd: correct the wrong sequence of arguments
  dt-bindings: serial: Convert riscv,sifive-serial to json-schema
  serial: max310x: turn off transmitter before activating AutoCTS or auto transmitter flow control
  serial: max310x: Properly set flags in AutoCTS mode
  tty: serial: fix platform_no_drv_owner.cocci warnings
  dt-bindings: serial: Document Freescale LINFlexD UART
  serial: fsl_linflexuart: Update compatible string
  tty: n_gsm: avoid recursive locking with async port hangup
  ...
2019-09-18 10:50:47 -07:00
Linus Torvalds 7ad67ca553 Merge tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:

 - Two NVMe pull requests:
     - ana log parse fix from Anton
     - nvme quirks support for Apple devices from Ben
     - fix missing bio completion tracing for multipath stack devices
       from Hannes and Mikhail
     - IP TOS settings for nvme rdma and tcp transports from Israel
     - rq_dma_dir cleanups from Israel
     - tracing for Get LBA Status command from Minwoo
     - Some nvme-tcp cleanups from Minwoo, Potnuri and Myself
     - Some consolidation between the fabrics transports for handling
       the CAP register
     - reset race with ns scanning fix for fabrics (move fabrics
       commands to a dedicated request queue with a different lifetime
       from the admin request queue)."
     - controller reset and namespace scan races fixes
     - nvme discovery log change uevent support
     - naming improvements from Keith
     - multiple discovery controllers reject fix from James
     - some regular cleanups from various people

 - Series fixing (and re-fixing) null_blk debug printing and nr_devices
   checks (André)

 - A few pull requests from Song, with fixes from Andy, Guoqing,
   Guilherme, Neil, Nigel, and Yufen.

 - REQ_OP_ZONE_RESET_ALL support (Chaitanya)

 - Bio merge handling unification (Christoph)

 - Pick default elevator correctly for devices with special needs
   (Damien)

 - Block stats fixes (Hou)

 - Timeout and support devices nbd fixes (Mike)

 - Series fixing races around elevator switching and device add/remove
   (Ming)

 - sed-opal cleanups (Revanth)

 - Per device weight support for BFQ (Fam)

 - Support for blk-iocost, a new model that can properly account cost of
   IO workloads. (Tejun)

 - blk-cgroup writeback fixes (Tejun)

 - paride queue init fixes (zhengbin)

 - blk_set_runtime_active() cleanup (Stanley)

 - Block segment mapping optimizations (Bart)

 - lightnvm fixes (Hans/Minwoo/YueHaibing)

 - Various little fixes and cleanups

* tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-block: (186 commits)
  null_blk: format pr_* logs with pr_fmt
  null_blk: match the type of parameter nr_devices
  null_blk: do not fail the module load with zero devices
  block: also check RQF_STATS in blk_mq_need_time_stamp()
  block: make rq sector size accessible for block stats
  bfq: Fix bfq linkage error
  raid5: use bio_end_sector in r5_next_bio
  raid5: remove STRIPE_OPS_REQ_PENDING
  md: add feature flag MD_FEATURE_RAID0_LAYOUT
  md/raid0: avoid RAID0 data corruption due to layout confusion.
  raid5: don't set STRIPE_HANDLE to stripe which is in batch list
  raid5: don't increment read_errors on EILSEQ return
  nvmet: fix a wrong error status returned in error log page
  nvme: send discovery log page change events to userspace
  nvme: add uevent variables for controller devices
  nvme: enable aen regardless of the presence of I/O queues
  nvme-fabrics: allow discovery subsystems accept a kato
  nvmet: Use PTR_ERR_OR_ZERO() in nvmet_init_discovery()
  nvme: Remove redundant assignment of cq vector
  nvme: Assign subsys instance from first ctrl
  ...
2019-09-17 16:57:47 -07:00
Linus Torvalds 7c672abc12 Merge tag 'docs-5.4' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "It's a somewhat calmer cycle for docs this time, as the churn of the
  mass RST conversion is happily mostly behind us.

   - A new document on reproducible builds.

   - We finally got around to zapping the documentation for hardware
     support that was removed in 2004; one doesn't want to rush these
     things.

   - The usual assortment of fixes, typo corrections, etc"

* tag 'docs-5.4' of git://git.lwn.net/linux: (67 commits)
  Documentation: kbuild: Add document about reproducible builds
  docs: printk-formats: Stop encouraging use of unnecessary %h[xudi] and %hh[xudi]
  Documentation: Add "earlycon=sbi" to the admin guide
  doc🔒 remove reference to clever use of read-write lock
  devices.txt: improve entry for comedi (char major 98)
  docs: mtd: Update spi nor reference driver
  doc: arm64: fix grammar dtb placed in no attributes region
  Documentation: sysrq: don't recommend 'S' 'U' before 'B'
  mailmap: Update email address for Quentin Perret
  docs: ftrace: clarify when tracing is disabled by the trace file
  docs: process: fix broken link
  Documentation/arm/samsung-s3c24xx: Remove stray U+FEFF character to fix title
  Documentation/arm/sa1100/assabet: Fix 'make assabet_defconfig' command
  Documentation/arm/sa1100: Remove some obsolete documentation
  docs/zh_CN: update Chinese howto.rst for latexdocs making
  Documentation: virt: Fix broken reference to virt tree's index
  docs: Fix typo on pull requests guide
  kernel-doc: Allow anonymous enum
  Documentation: sphinx: Don't parse socket() as identifier reference
  Documentation: sphinx: Add missing comma to list of strings
  ...
2019-09-17 16:22:26 -07:00
Linus Torvalds ad06219573 Merge tag 'platform-drivers-x86-v5.4-1' of git://git.infradead.org/linux-platform-drivers-x86
Pull x86 platform-drivers updates from Andy Shevchenko:

 - ASUS WMI driver got a couple of updates, i.e. support of FAN is fixed
   for recent products and the charge threshold support has been added

 - Two uknown key events for Dell laptops are being ignored now to avoid
   spamming users with harmless messages

 - HP ZBook 17 G5 and ASUS Zenbook UX430UNR got accelerometer support.

 - Intel CherryTrail platforms had a regression with wake up. Now it's
   fixed

 - Intel PMC driver got fixed in order to work nicely in Xen
   environment

 - Intel Speed Select driver provides bucket vs core count relationship.
   Besides that the tools has been updated for better output

 - The PrivacyGuard is enabled on Lenovo ThinkPad laptops

 - Three tablets - Trekstor Primebook C11B 2-in-1, Irbis TW90 and Chuwi
   Surbook Mini - got touchscreen support

* tag 'platform-drivers-x86-v5.4-1' of git://git.infradead.org/linux-platform-drivers-x86: (53 commits)
  MAINTAINERS: Switch PDx86 subsystem status to Odd Fixes
  platform/x86: asus-wmi: Refactor charge threshold to use the battery hooking API
  platform/x86: asus-wmi: Rename CHARGE_THRESHOLD to RSOC
  platform/x86: asus-wmi: Reorder ASUS_WMI_CHARGE_THRESHOLD
  tools/power/x86/intel-speed-select: Display core count for bucket
  platform/x86: ISST: Allow additional TRL MSRs
  tools/power/x86/intel-speed-select: Fix memory leak
  tools/power/x86/intel-speed-select: Output success/failed for command output
  tools/power/x86/intel-speed-select: Output human readable CPU list
  tools/power/x86/intel-speed-select: Change turbo ratio output to maximum turbo frequency
  tools/power/x86/intel-speed-select: Switch output to MHz
  tools/power/x86/intel-speed-select: Simplify output for turbo-freq and base-freq
  tools/power/x86/intel-speed-select: Fix cpu-count output
  tools/power/x86/intel-speed-select: Fix help option typo
  tools/power/x86/intel-speed-select: Fix package typo
  tools/power/x86/intel-speed-select: Fix a read overflow in isst_set_tdp_level_msr()
  platform/x86: intel_int0002_vgpio: Use device_init_wakeup
  platform/x86: intel_int0002_vgpio: Fix wakeups not working on Cherry Trail
  platform/x86: compal-laptop: Initialize "value" in ec_read_u8()
  platform/x86: touchscreen_dmi: Add info for the Trekstor Primebook C11B 2-in-1
  ...
2019-09-16 19:59:10 -07:00
Linus Torvalds 7e67a85999 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:

 - MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and
   Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann,
   Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers.

   As perf and the scheduler is getting bigger and more complex,
   document the status quo of current responsibilities and interests,
   and spread the review pain^H^H^H^H fun via an increase in the Cc:
   linecount generated by scripts/get_maintainer.pl. :-)

 - Add another series of patches that brings the -rt (PREEMPT_RT) tree
   closer to mainline: split the monolithic CONFIG_PREEMPT dependencies
   into a new CONFIG_PREEMPTION category that will allow the eventual
   introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches
   to go though.

 - Extend the CPU cgroup controller with uclamp.min and uclamp.max to
   allow the finer shaping of CPU bandwidth usage.

 - Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS).

 - Improve the behavior of high CPU count, high thread count
   applications running under cpu.cfs_quota_us constraints.

 - Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present.

 - Improve CPU isolation housekeeping CPU allocation NUMA locality.

 - Fix deadline scheduler bandwidth calculations and logic when cpusets
   rebuilds the topology, or when it gets deadline-throttled while it's
   being offlined.

 - Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from
   setscheduler() system calls without creating global serialization.
   Add new synchronization between cpuset topology-changing events and
   the deadline acceptance tests in setscheduler(), which were broken
   before.

 - Rework the active_mm state machine to be less confusing and more
   optimal.

 - Rework (simplify) the pick_next_task() slowpath.

 - Improve load-balancing on AMD EPYC systems.

 - ... and misc cleanups, smaller fixes and improvements - please see
   the Git log for more details.

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  sched/psi: Correct overly pessimistic size calculation
  sched/fair: Speed-up energy-aware wake-ups
  sched/uclamp: Always use 'enum uclamp_id' for clamp_id values
  sched/uclamp: Update CPU's refcount on TG's clamp changes
  sched/uclamp: Use TG's clamps to restrict TASK's clamps
  sched/uclamp: Propagate system defaults to the root group
  sched/uclamp: Propagate parent clamps
  sched/uclamp: Extend CPU's cgroup controller
  sched/topology: Improve load balancing on AMD EPYC systems
  arch, ia64: Make NUMA select SMP
  sched, perf: MAINTAINERS update, add submaintainers and reviewers
  sched/fair: Use rq_lock/unlock in online_fair_sched_group
  cpufreq: schedutil: fix equation in comment
  sched: Rework pick_next_task() slow-path
  sched: Allow put_prev_task() to drop rq->lock
  sched/fair: Expose newidle_balance()
  sched: Add task_struct pointer to sched_class::set_curr_task
  sched: Rework CPU hotplug task selection
  sched/{rt,deadline}: Fix set_next_task vs pick_next_task
  sched: Fix kerneldoc comment for ia64_set_curr_task
  ...
2019-09-16 17:25:49 -07:00
Linus Torvalds 94d18ee934 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "This cycle's RCU changes were:

   - A few more RCU flavor consolidation cleanups.

   - Updates to RCU's list-traversal macros improving lockdep usability.

   - Forward-progress improvements for no-CBs CPUs: Avoid ignoring
     incoming callbacks during grace-period waits.

   - Forward-progress improvements for no-CBs CPUs: Use ->cblist
     structure to take advantage of others' grace periods.

   - Also added a small commit that avoids needlessly inflicting
     scheduler-clock ticks on callback-offloaded CPUs.

   - Forward-progress improvements for no-CBs CPUs: Reduce contention on
     ->nocb_lock guarding ->cblist.

   - Forward-progress improvements for no-CBs CPUs: Add ->nocb_bypass
     list to further reduce contention on ->nocb_lock guarding ->cblist.

   - Miscellaneous fixes.

   - Torture-test updates.

   - minor LKMM updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (86 commits)
  MAINTAINERS: Update from paulmck@linux.ibm.com to paulmck@kernel.org
  rcu: Don't include <linux/ktime.h> in rcutiny.h
  rcu: Allow rcu_do_batch() to dynamically adjust batch sizes
  rcu/nocb: Don't wake no-CBs GP kthread if timer posted under overload
  rcu/nocb: Reduce __call_rcu_nocb_wake() leaf rcu_node ->lock contention
  rcu/nocb: Reduce nocb_cb_wait() leaf rcu_node ->lock contention
  rcu/nocb: Advance CBs after merge in rcutree_migrate_callbacks()
  rcu/nocb: Avoid synchronous wakeup in __call_rcu_nocb_wake()
  rcu/nocb: Print no-CBs diagnostics when rcutorture writer unduly delayed
  rcu/nocb: EXP Check use and usefulness of ->nocb_lock_contended
  rcu/nocb: Add bypass callback queueing
  rcu/nocb: Atomic ->len field in rcu_segcblist structure
  rcu/nocb: Unconditionally advance and wake for excessive CBs
  rcu/nocb: Reduce ->nocb_lock contention with separate ->nocb_gp_lock
  rcu/nocb: Reduce contention at no-CBs invocation-done time
  rcu/nocb: Reduce contention at no-CBs registry-time CB advancement
  rcu/nocb: Round down for number of no-CBs grace-period kthreads
  rcu/nocb: Avoid ->nocb_lock capture by corresponding CPU
  rcu/nocb: Avoid needless wakeups of no-CBs grace-period kthread
  rcu/nocb: Make __call_rcu_nocb_wake() safe for many callbacks
  ...
2019-09-16 16:28:19 -07:00
Linus Torvalds 76f0f227cf Merge tag 'please-pull-ia64_for_5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux
Pull ia64 updates from Tony Luck:
 "The big change here is removal of support for SGI Altix"

* tag 'please-pull-ia64_for_5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux: (33 commits)
  genirq: remove the is_affinity_mask_valid hook
  ia64: remove CONFIG_SWIOTLB ifdefs
  ia64: remove support for machvecs
  ia64: move the screen_info setup to common code
  ia64: move the ROOT_DEV setup to common code
  ia64: rework iommu probing
  ia64: remove the unused sn_coherency_id symbol
  ia64: remove the SGI UV simulator support
  ia64: remove the zx1 swiotlb machvec
  ia64: remove CONFIG_ACPI ifdefs
  ia64: remove CONFIG_PCI ifdefs
  ia64: remove the hpsim platform
  ia64: remove now unused machvec indirections
  ia64: remove support for the SGI SN2 platform
  drivers: remove the SGI SN2 IOC4 base support
  drivers: remove the SGI SN2 IOC3 base support
  qla2xxx: remove SGI SN2 support
  qla1280: remove SGI SN2 support
  misc/sgi-xp: remove SGI SN2 support
  char/mspec: remove SGI SN2 support
  ...
2019-09-16 15:32:01 -07:00
Linus Torvalds e77fafe9af Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
 "Although there isn't tonnes of code in terms of line count, there are
  a fair few headline features which I've noted both in the tag and also
  in the merge commits when I pulled everything together.

  The part I'm most pleased with is that we had 35 contributors this
  time around, which feels like a big jump from the usual small group of
  core arm64 arch developers. Hopefully they all enjoyed it so much that
  they'll continue to contribute, but we'll see.

  It's probably worth highlighting that we've pulled in a branch from
  the risc-v folks which moves our CPU topology code out to where it can
  be shared with others.

  Summary:

   - 52-bit virtual addressing in the kernel

   - New ABI to allow tagged user pointers to be dereferenced by
     syscalls

   - Early RNG seeding by the bootloader

   - Improve robustness of SMP boot

   - Fix TLB invalidation in light of recent architectural
     clarifications

   - Support for i.MX8 DDR PMU

   - Remove direct LSE instruction patching in favour of static keys

   - Function error injection using kprobes

   - Support for the PPTT "thread" flag introduced by ACPI 6.3

   - Move PSCI idle code into proper cpuidle driver

   - Relaxation of implicit I/O memory barriers

   - Build with RELR relocations when toolchain supports them

   - Numerous cleanups and non-critical fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (114 commits)
  arm64: remove __iounmap
  arm64: atomics: Use K constraint when toolchain appears to support it
  arm64: atomics: Undefine internal macros after use
  arm64: lse: Make ARM64_LSE_ATOMICS depend on JUMP_LABEL
  arm64: asm: Kill 'asm/atomic_arch.h'
  arm64: lse: Remove unused 'alt_lse' assembly macro
  arm64: atomics: Remove atomic_ll_sc compilation unit
  arm64: avoid using hard-coded registers for LSE atomics
  arm64: atomics: avoid out-of-line ll/sc atomics
  arm64: Use correct ll/sc atomic constraints
  jump_label: Don't warn on __exit jump entries
  docs/perf: Add documentation for the i.MX8 DDR PMU
  perf/imx_ddr: Add support for AXI ID filtering
  arm64: kpti: ensure patched kernel text is fetched from PoU
  arm64: fix fixmap copy for 16K pages and 48-bit VA
  perf/smmuv3: Validate groups for global filtering
  perf/smmuv3: Validate group size
  arm64: Relax Documentation/arm64/tagged-pointers.rst
  arm64: kvm: Replace hardcoded '1' with SYS_PAR_EL1_F
  arm64: mm: Ignore spurious translation faults taken from the kernel
  ...
2019-09-16 14:31:40 -07:00
Ingo Molnar 563c4f85f9 Merge branch 'sched/rt' into sched/core, to pick up -rt changes
Pick up the first couple of patches working towards PREEMPT_RT.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-16 14:05:04 +02:00
Palmer Dabbelt 82f12ab311 Documentation: Add "earlycon=sbi" to the admin guide
This argument is supported on RISC-V systems and widely used, but was
not documented here.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-09-14 01:55:27 -06:00
Ian Abbott d62e8055a5 devices.txt: improve entry for comedi (char major 98)
Describe how the comedi minor device numbers are split across comedi
devices and comedi subdevices.

Replace the current, long dead URL with an official URL for the Comedi
project.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-09-14 01:51:46 -06:00
Nikos Tsironis 7431b7835f dm: add clone target
Add the dm-clone target, which allows cloning of arbitrary block
devices.

dm-clone produces a one-to-one copy of an existing, read-only source
device into a writable destination device: It presents a virtual block
device which makes all data appear immediately, and redirects reads and
writes accordingly.

The main use case of dm-clone is to clone a potentially remote,
high-latency, read-only, archival-type block device into a writable,
fast, primary-type device for fast, low-latency I/O. The cloned device
is visible/mountable immediately and the copy of the source device to
the destination device happens in the background, in parallel with user
I/O.

When the cloning completes, the dm-clone table can be removed altogether
and be replaced, e.g., by a linear table, mapping directly to the
destination device.

For further information and examples of how to use dm-clone, please read
Documentation/admin-guide/device-mapper/dm-clone.rst

Suggested-by: Vangelis Koukis <vkoukis@arrikto.com>
Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-12 09:32:31 -04:00
Joerg Roedel e95adb9add Merge branches 'arm/omap', 'arm/exynos', 'arm/smmu', 'arm/mediatek', 'arm/qcom', 'arm/renesas', 'x86/amd', 'x86/vt-d' and 'core' into next 2019-09-11 12:39:19 +02:00
Lu Baolu e5e04d0519 iommu/vt-d: Check whether device requires bounce buffer
This adds a helper to check whether a device needs to
use bounce buffer. It also provides a boot time option
to disable the bounce buffer. Users can use this to
prevent the iommu driver from using the bounce buffer
for performance gain.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Xu Pengfei <pengfei.xu@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2019-09-11 12:34:29 +02:00
Alexander Schremmer 110ea1d833 platform/x86: thinkpad_acpi: Add ThinkPad PrivacyGuard
This feature is found optionally in T480s, T490, T490s.

The feature is called lcdshadow and visible via
/proc/acpi/ibm/lcdshadow.

The ACPI methods \_SB.PCI0.LPCB.EC.HKEY.{GSSS,SSSS,TSSS,CSSS} are
available in these machines. They get, set, toggle or change the state
apparently.

The patch was tested on a 5.0 series kernel on a T480s.

Signed-off-by: Alexander Schremmer <alex@alexanderweb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2019-09-07 21:16:09 +03:00
Adam Borowski 209c3aa7f0 Documentation: sysrq: don't recommend 'S' 'U' before 'B'
This advice is obsolete and slightly harmful for filesystems from this
millenium: any modern filesystem can handle unexpected crashes without
requiring fsck -- and on the other hand, trying to write to the disk when
the kernel is in a bad state risks introducing corruption.

For ext2, any unsafe shutdown meant widespread breakage, but it's no longer
a reasonable filesystem for any non-special use.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-09-06 08:42:52 -06:00
Nicholas Piggin 2275d7b575 powerpc/64s/radix: introduce options to disable use of the tlbie instruction
Introduce two options to control the use of the tlbie instruction. A
boot time option which completely disables the kernel using the
instruction, this is currently incompatible with HASH MMU, KVM, and
coherent accelerators.

And a debugfs option can be switched at runtime and avoids using tlbie
for invalidating CPU TLBs for normal process and kernel address
mappings. Coherent accelerators are still managed with tlbie, as will
KVM partition scope translations.

Cross-CPU TLB flushing is implemented with IPIs and tlbiel. This is a
basic implementation which does not attempt to make any optimisation
beyond the tlbie implementation.

This is useful for performance testing among other things. For example
in certain situations on large systems, using IPIs may be faster than
tlbie as they can be directed rather than broadcast. Later we may also
take advantage of the IPIs to do more interesting things such as trim
the mm cpumask more aggressively.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190902152931.17840-7-npiggin@gmail.com
2019-09-05 14:22:41 +10:00
Stefan-gabriel Mirea 09864c1cdf tty: serial: Add linflexuart driver for S32V234
Introduce support for LINFlex driver, based on:
- the version of Freescale LPUART driver after commit b3e3bf2ef2 ("Merge
  4.0-rc7 into tty-next");
- commit abf1e0a980 ("tty: serial: fsl_lpuart: lock port on console
  write").
In this basic version, the driver can be tested using initramfs and relies
on the clocks and pin muxing set up by U-Boot.

Remarks concerning the earlycon support:

- LinFlexD does not allow character transmissions in the INIT mode (see
  section 47.4.2.1 in the reference manual[1]). Therefore, a mutual
  exclusion between the first linflex_setup_watermark/linflex_set_termios
  executions and linflex_earlycon_putchar was employed and the characters
  normally sent to earlycon during initialization are kept in a buffer and
  sent afterwards.

- Empirically, character transmission is also forbidden within the last 1-2
  ms before entering the INIT mode, so we use an explicit timeout
  (PREINIT_DELAY) between linflex_earlycon_putchar and the first call to
  linflex_setup_watermark.

- U-Boot currently uses the UART FIFO mode, while this driver makes the
  transition to the buffer mode. Therefore, the earlycon putchar function
  matches the U-Boot behavior before initializations and the Linux behavior
  after.

[1] https://www.nxp.com/webapp/Download?colCode=S32V234RM

Signed-off-by: Stoica Cosmin-Stefan <cosmin.stoica@nxp.com>
Signed-off-by: Adrian.Nitu <adrian.nitu@freescale.com>
Signed-off-by: Larisa Grigore <Larisa.Grigore@nxp.com>
Signed-off-by: Ana Nedelcu <B56683@freescale.com>
Signed-off-by: Mihaela Martinas <Mihaela.Martinas@freescale.com>
Signed-off-by: Matthew Nunez <matthew.nunez@nxp.com>
[stefan-gabriel.mirea@nxp.com: Reduced for upstreaming and implemented
                               earlycon support]
Signed-off-by: Stefan-Gabriel Mirea <stefan-gabriel.mirea@nxp.com>
Link: https://lore.kernel.org/r/20190809112853.15846-6-stefan-gabriel.mirea@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04 12:43:54 +02:00