The ghes registration and refcount is broken in several ways:

 * ghes_edac_register() returns with success for a 2nd instance
   even if a first instance's registration is still running. This is
   not correct as the first instance may fail later. A subsequent
   registration may not finish before the first. Parallel registrations
   must be avoided.

 * The refcount was increased even if a registration failed. This
   leads to stale counters preventing the device from being released.

 * The ghes refcount may not be decremented properly on unregistration.
   Always decrement the refcount once ghes_edac_unregister() is called to
   keep the refcount sane.

 * The ghes_pvt pointer is handed to the irq handler before registration
   finished.

 * The mci structure could be freed while the irq handler is running.

Fix this by adding a mutex to ghes_edac_register(). This mutex
serializes instances to register and unregister. The refcount is only
increased if the registration succeeded. This makes sure the refcount is
in a consistent state after registering or unregistering a device.

Note: A spinlock cannot be used here as the code section may sleep.

The ghes_pvt is protected by ghes_lock now. This ensures the pointer is
not updated before registration was finished or while the irq handler is
running. It is unset before unregistering the device including necessary
(implicit) memory barriers making the changes visible to other CPUs.
Thus, the device can not be used anymore by an interrupt.

Also, rename ghes_init to ghes_refcount for better readability and
switch to refcount API.

A refcount is needed because there can be multiple GHES structures being
defined (see ACPI 6.3 specification, 18.3.2.7 Generic Hardware Error
Source, "Some platforms may describe multiple Generic Hardware Error
Source structures with different notification types, ...").

Another approach to use the mci's device refcount (get_device()) and
have a release function does not work here. A release function will be
called only for device_release() with the last put_device() call. The
device must be deleted *before* that with device_del(). This is only
possible by maintaining an own refcount.

 [ bp: touchups. ]

Fixes: 0fe5f281 ("EDAC, ghes: Model a single, logical memory controller")
Fixes: 1e72e673 ("EDAC/ghes: Fix Use after free in ghes_edac remove path")
Co-developed-by: James Morse <james.morse@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Co-developed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20191105200732.3053-1-rrichter@marvell.com

Return early before checking for ECC if the node does not have any
populated memory.

Free any cached hardware data before returning. Also, return 0 in this
case since this is not a failure. Other nodes may have memory and the
module should attempt to load an instance for them.

Move printing of hardware information to after the instance is
initialized, so that the information is only printed for nodes with
memory.

Return an error code when ECC is disabled. This check happens after
checking for memory. The module should explicitly fail to load if memory
is populated on a node and ECC is disabled.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rrichter@marvell.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20191106012448.243970-6-Yazen.Ghannam@amd.com

...now that the data is available earlier.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rrichter@marvell.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20191106012448.243970-5-Yazen.Ghannam@amd.com

The maximum number of memory controllers is fixed within a family/model
group. In most cases, this has been fixed at 2, but some systems may
have up to 8.

The struct amd64_family_type already contains family/model-specific
information, and this can be used rather than adding model checks to
various functions.

Create a new field in struct amd64_family_type for max_mcs.
Set this when setting other family type information, and use this when
needing the maximum number of memory controllers possible for a system.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rrichter@marvell.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20191106012448.243970-4-Yazen.Ghannam@amd.com

Split out gathering hardware information from init_one_instance()
into a separate function hw_info_get(). This is necessary so that
the information can be cached earlier and used to check if memory is
populated and if ECC is enabled on a node.

Also, define a function hw_info_put() to back out changes made in
hw_info_get().

Check for an allocated PCI device (Function 0 for Family 17h or Function
1 for pre-Family 17h) before freeing, since hw_info_put() may be called
before PCI siblings are reserved.

Drop the family check when freeing pvt->umc. This will be NULL on
pre-Family 17h systems. However, kfree() is safe and will check for a
NULL pointer before freeing.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rrichter@marvell.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20191106012448.243970-3-Yazen.Ghannam@amd.com

The struct amd64_family_type doesn't change between multiple nodes and
instances of the module, so make it global.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rrichter@marvell.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20191106012448.243970-2-Yazen.Ghannam@amd.com

The following commit introduced a warning on error reports without a
non-zero grain value.

  3724ace5 ("EDAC/mc: Fix grain_bits calculation")

The amd64_edac_mod module does not provide a value, so the warning will
be given on the first reported memory error.

Set the grain per DIMM to cacheline size (64 bytes). This is the current
recommendation.

Fixes: 3724ace5 ("EDAC/mc: Fix grain_bits calculation")
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rrichter@marvell.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20191022203448.13962-7-Yazen.Ghannam@amd.com

Simplify this function implementation by using a known wrapper function.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Joel Stanley <joel@jms.id.au>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: James Morse <james.morse@arm.com>
Cc: kernel-janitors@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-aspeed@lists.ozlabs.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rrichter@marvell.com>
Cc: Stefan Schaeckeler <sschaeck@cisco.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/baabb9e9-a1b2-3a04-9fb6-aa632de5f722@web.de

Skylake logs some additional useful information in per-channel
registers in addition the the architectural status/addr/misc
logged in the machine check bank.

Pick up this information and add it to the EDAC log:

	retry_rd_err_[five 32-bit register values]

Sorry, no definitions for these registers. OEMs and DIMM vendors
will be able to use them to isolate which cells in the DIMM are
causing problems.

	correrrcnt[per rank corrected error counts]

Note that if additional errors are logged while these registers are
being read, you may see a jumble of values some from earlier errors,
others from later errors (since the registers report the most recent
logged error). The correrrcnt registers provide error counts per possible
rank. If these counts only change by one since the previous error logged
for this channel, then it is safe to assume that the registers logged
provide a coherent view of one error.

With this change EDAC logs look like this:

EDAC MC4: 1 CE memory read error on CPU_SrcID#2_MC#0_Chan#1_DIMM#0 (channel:1 slot:0 page:0x8f26018 offset:0x0 grain:32 syndrome:0x0 -  err_code:0x0101:0x0091 socket:2 imc:0 rank:0 bg:0 ba:0 row:0x1f880 col:0x200 retry_rd_err_log[0001a209 00000000 00000001 04800001 0001f880] correrrcnt[0001 0000 0000 0000 0000 0000 0000 0000])
Acked-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Simplifies the code a little.
Acked-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Pick up urgent change into next queue.
Signed-off-by: Borislav Petkov <bp@suse.de>

ghes_edac models a single logical memory controller, and uses a global
ghes_init variable to ensure only the first ghes_edac_register() will
do anything.

ghes_edac is registered the first time a GHES entry in the HEST is
probed. There may be multiple entries, so subsequent attempts to
register ghes_edac are silently ignored as the work has already been
done.

When a GHES entry is unregistered, it calls ghes_edac_unregister(),
which free()s the memory behind the global variables in ghes_edac.

But there may be multiple GHES entries, the next call to
ghes_edac_unregister() will dereference the free()d memory, and attempt
to free it a second time.

This may also be triggered on a platform with one GHES entry, if the
driver is unbound/re-bound and unbound. The re-bind step will do
nothing because of ghes_init, the second unbind will then do the same
work as the first.

Doing the unregister work on the first call is unsafe, as another
CPU may be processing a notification in ghes_edac_report_mem_error(),
using the memory we are about to free.

ghes_init is already half of the reference counting. We only need
to do the register work for the first call, and the unregister work
for the last. Add the unregister check.

This means we no longer free ghes_edac's memory while there are
GHES entries that may receive a notification.

This was detected by KASAN and DEBUG_TEST_DRIVER_REMOVE.

 [ bp: merge into a single patch. ]

Fixes: 0fe5f281 ("EDAC, ghes: Model a single, logical memory controller")
Reported-by: John Garry <john.garry@huawei.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Robert Richter <rrichter@marvell.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20191014171919.85044-2-james.morse@arm.com
Link: https://lkml.kernel.org/r/304df85b-8b56-b77e-1a11-aa23769f2e7c@huawei.com

Make the main workhorse the "count" functions which can log a @count
of errors. Have the current APIs edac_device_handle_{ce,ue}() call
the _count() variants and this way keep the exported symbols number
unchanged.

 [ bp: Rewrite. ]
Signed-off-by: Hanna Hawa <hhhawa@amazon.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: benh@amazon.com
Cc: dwmw@amazon.co.uk
Cc: hanochu@amazon.com
Cc: James Morse <james.morse@arm.com>
Cc: jonnyc@amazon.com
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: ronenk@amazon.com
Cc: talel@amazon.com
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20190923191741.29322-2-hhhawa@amazon.com

	drivers/edac/skx_common.c: In function ‘skx_mce_output_error’:
	drivers/edac/skx_common.c:478:8: warning: variable ‘type’ set but not used [-Wunused-but-set-variable]
	  478 |  char *type, *optype;
	      |        ^~~~
Acked-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

There are several vars unused on this driver, probably because
it was a modified copy of another driver. Get rid of them.

	drivers/edac/sb_edac.c: In function ‘knl_get_dimm_capacity’:
	drivers/edac/sb_edac.c:1343:16: warning: variable ‘sad_size’ set but not used [-Wunused-but-set-variable]
	 1343 |  u64 sad_base, sad_size, sad_limit = 0;
	      |                ^~~~~~~~
	drivers/edac/sb_edac.c: In function ‘sbridge_mce_output_error’:
	drivers/edac/sb_edac.c:2955:8: warning: variable ‘type’ set but not used [-Wunused-but-set-variable]
	 2955 |  char *type, *optype, msg[256];
	      |        ^~~~
	drivers/edac/sb_edac.c: In function ‘sbridge_unregister_mci’:
	drivers/edac/sb_edac.c:3203:22: warning: variable ‘pvt’ set but not used [-Wunused-but-set-variable]
	 3203 |  struct sbridge_pvt *pvt;
	      |                      ^~~
	At top level:
	drivers/edac/sb_edac.c:266:18: warning: ‘correrrthrsld’ defined but not used [-Wunused-const-variable=]
	  266 | static const u32 correrrthrsld[] = {
	      |                  ^~~~~~~~~~~~~
	drivers/edac/sb_edac.c:257:18: warning: ‘correrrcnt’ defined but not used [-Wunused-const-variable=]
	  257 | static const u32 correrrcnt[] = {
	      |                  ^~~~~~~~~~
Acked-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

There are several temporary unused vars:

	drivers/edac/i5400_edac.c: In function ‘i5400_get_mc_regs’:
	drivers/edac/i5400_edac.c:1058:6: warning: variable ‘maxdimmperch’ set but not used [-Wunused-but-set-variable]
	 1058 |  int maxdimmperch;
	      |      ^~~~~~~~~~~~
	drivers/edac/i5400_edac.c:1057:6: warning: variable ‘maxch’ set but not used [-Wunused-but-set-variable]
	 1057 |  int maxch;
	      |      ^~~~~
	drivers/edac/i5400_edac.c: In function ‘i5400_init_dimms’:
	drivers/edac/i5400_edac.c:1174:6: warning: variable ‘max_dimms’ set but not used [-Wunused-but-set-variable]
	 1174 |  int max_dimms;
	      |      ^~~~~~~~~
	drivers/edac/i5400_edac.c:1173:14: warning: variable ‘channel_count’ set but not used [-Wunused-but-set-variable]
	 1173 |  int ndimms, channel_count;
	      |              ^~~~~~~~~~~~~

Get rid of them.
Acked-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

There are 3 types of non-recoverable errors that the MC reports:

	- Fatal;
	- Non-fatal uncorrected
	- Non-fatal correctable

While we don't add it to the log itself, it could be useful to
have this at least for debug messages.

This shuts up this warning:

	drivers/edac/i5400_edac.c: In function ‘i5400_proccess_non_recoverable_info’:
	drivers/edac/i5400_edac.c:524:8: warning: variable ‘type’ set but not used [-Wunused-but-set-variable]
	  524 |  char *type = NULL;
	      |        ^~~~
Acked-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

The declaration of the kerneldoc entry is wrong, causing this
warning:

	drivers/edac/i7300_edac.c:824: warning: Function parameter or member 'mir_no' not described in 'decode_mir'
Acked-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

One var was renamed, but the associated kernel-doc markup still
points to the old name.
Acked-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

As reported by GCC with W=1:

	drivers/edac/i5100_edac.c:714:16: warning: variable ‘et’ set but not used [-Wunused-but-set-variable]
	  714 |  unsigned long et;
	      |                ^~

It sounds some left over from some code before the addition of
an udelay().
Acked-by: Borislav Petkov <bp@alien8.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Pull btrfs fixes from David Sterba:
 "A bunch of fixes that accumulated in recent weeks, mostly material for
  stable.

  Summary:

   - fix for regression from 5.3 that prevents to use balance convert
     with single profile

   - qgroup fixes: rescan race, accounting leak with multiple writers,
     potential leak after io failure recovery

   - fix for use after free in relocation (reported by KASAN)

   - other error handling fixups"

* tag 'for-5.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: qgroup: Fix reserved data space leak if we have multiple reserve calls
  btrfs: qgroup: Fix the wrong target io_tree when freeing reserved data space
  btrfs: Fix a regression which we can't convert to SINGLE profile
  btrfs: relocation: fix use-after-free on dead relocation roots
  Btrfs: fix race setting up and completing qgroup rescan workers
  Btrfs: fix missing error return if writeback for extent buffer never started
  btrfs: adjust dirty_metadata_bytes after writeback failure of extent buffer
  Btrfs: fix selftests failure due to uninitialized i_mode in test inodes

Pull csky updates from Guo Ren:
 "This round of csky subsystem just some fixups:

   - Fix mb() synchronization problem

   - Fix dma_alloc_coherent with PAGE_SO attribute

   - Fix cache_op failed when cross memory ZONEs

   - Optimize arch_sync_dma_for_cpu/device with dma_inv_range

   - Fix ioremap function losing

   - Fix arch_get_unmapped_area() implementation

   - Fix defer cache flush for 610

   - Support kernel non-aligned access

   - Fix 610 vipt cache flush mechanism

   - Fix add zero_fp fixup perf backtrace panic

   - Move static keyword to the front of declaration

   - Fix csky_pmu.max_period assignment

   - Use generic free_initrd_mem()

   - entry: Remove unneeded need_resched() loop"

* tag 'csky-for-linus-5.4-rc1' of git://github.com/c-sky/csky-linux:
  csky: Move static keyword to the front of declaration
  csky: entry: Remove unneeded need_resched() loop
  csky: Fixup csky_pmu.max_period assignment
  csky: Fixup add zero_fp fixup perf backtrace panic
  csky: Use generic free_initrd_mem()
  csky: Fixup 610 vipt cache flush mechanism
  csky: Support kernel non-aligned access
  csky: Fixup defer cache flush for 610
  csky: Fixup arch_get_unmapped_area() implementation
  csky: Fixup ioremap function losing
  csky: Optimize arch_sync_dma_for_cpu/device with dma_inv_range
  csky/dma: Fixup cache_op failed when cross memory ZONEs
  csky: Fixup dma_alloc_coherent with PAGE_SO attribute
  csky: Fixup mb() synchronization problem

Pull ARM SoC fixes from Olof Johansson:
 "A few fixes that have trickled in through the merge window:

   - Video fixes for OMAP due to panel-dpi driver removal

   - Clock fixes for OMAP that broke no-idle quirks + nfsroot on DRA7

   - Fixing arch version on ASpeed ast2500

   - Two fixes for reset handling on ARM SCMI"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  ARM: aspeed: ast2500 is ARMv6K
  reset: reset-scmi: add missing handle initialisation
  firmware: arm_scmi: reset: fix reset_state assignment in scmi_domain_reset
  bus: ti-sysc: Remove unpaired sysc_clkdm_deny_idle()
  ARM: dts: logicpd-som-lv: Fix i2c2 and i2c3 Pin mux
  ARM: dts: am3517-evm: Fix missing video
  ARM: dts: logicpd-torpedo-baseboard: Fix missing video
  ARM: omap2plus_defconfig: Fix missing video
  bus: ti-sysc: Fix handling of invalid clocks
  bus: ti-sysc: Fix clock handling for no-idle quirks

Pull tracing fixes from Steven Rostedt:
 "A few more tracing fixes:

   - Fix a buffer overflow by checking nr_args correctly in probes

   - Fix a warning that is reported by clang

   - Fix a possible memory leak in error path of filter processing

   - Fix the selftest that checks for failures, but wasn't failing

   - Minor clean up on call site output of a memory trace event"

* tag 'trace-v5.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  selftests/ftrace: Fix same probe error test
  mm, tracing: Print symbol name for call_site in trace events
  tracing: Have error path in predicate_parse() free its allocated memory
  tracing: Fix clang -Wint-in-bool-context warnings in IF_ASSIGN macro
  tracing/probe: Fix to check the difference of nr_args before adding probe

Pull more MMC updates from Ulf Hansson:
 "A couple more updates/fixes for MMC:

   - sdhci-pci: Add Genesys Logic GL975x support

   - sdhci-tegra: Recover loss in throughput for DMA

   - sdhci-of-esdhc: Fix DMA bug"

* tag 'mmc-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: host: sdhci-pci: Add Genesys Logic GL975x support
  mmc: tegra: Implement ->set_dma_mask()
  mmc: sdhci: Let drivers define their DMA mask
  mmc: sdhci-of-esdhc: set DMA snooping based on DMA coherence
  mmc: sdhci: improve ADMA error reporting

Move the static keyword to the front of declaration of
csky_pmu_of_device_ids, and resolve the following compiler
warning that can be seen when building with warnings
enabled (W=1):

arch/csky/kernel/perf_event.c:1340:1: warning:
  ‘static’ is not at beginning of declaration [-Wold-style-declaration]
Signed-off-by: Krzysztof Wilczynski <kw@linux.com>
Signed-off-by: Guo Ren <guoren@kernel.org>

Since the enabling and disabling of IRQs within preempt_schedule_irq()
is contained in a need_resched() loop, we don't need the outer arch
code loop.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Guo Ren <guoren@kernel.org>

Pull Documentation/process update from Greg KH:
 "Here are two small Documentation/process/embargoed-hardware-issues.rst
  file updates that missed my previous char/misc pull request.

  The first one adds an Intel representative for the process, and the
  second one cleans up the text a bit more when it comes to how the
  disclosure rules work, as it was a bit confusing to some companies"

* tag 'char-misc-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Documentation/process: Clarify disclosure rules
  Documentation/process: Volunteer as the ambassador for Intel

Pull more vfs updates from Al Viro:
 "A couple of misc patches"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  afs dynroot: switch to simple_dir_operations
  fs/handle.c - fix up kerneldoc

Pull more cifs updates from Steve French:
 "Fixes from the recent SMB3 Test events and Storage Developer
  Conference (held the last two weeks).

  Here are nine smb3 patches including an important patch for debugging
  traces with wireshark, with three patches marked for stable.

  Additional fixes from last week to better handle some newly discovered
  reparse points, and a fix the create/mkdir path for setting the mode
  more atomically (in SMB3 Create security descriptor context), and one
  for path name processing are still being tested so are not included
  here"

* tag '5.4-rc-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Fix oplock handling for SMB 2.1+ protocols
  smb3: missing ACL related flags
  smb3: pass mode bits into create calls
  smb3: Add missing reparse tags
  CIFS: fix max ea value size
  fs/cifs/sess.c: Remove set but not used variable 'capabilities'
  fs/cifs/smb2pdu.c: Make SMB2_notify_init static
  smb3: fix leak in "open on server" perf counter
  smb3: allow decryption keys to be dumped by admin for debugging

The csky_pmu.max_period has type u64, and BIT() can only return
32 bits unsigned long on C-SKY. The initialization for max_period
will be incorrect when count_width is bigger than 32.

Use BIT_ULL()
Signed-off-by: Mao Han <han_mao@c-sky.com>
Signed-off-by: Guo Ren <ren_guo@c-sky.com>

We need set fp zero to let backtrace know the end. The patch fixup perf
callchain panic problem, because backtrace didn't know what is the end
of fp.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reported-by: Mao Han <han_mao@c-sky.com>

The csky implementation of free_initrd_mem() is an open-coded version of
free_reserved_area() without poisoning.

Remove it and make csky use the generic version of free_initrd_mem().
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Guo Ren <guoren@kernel.org>

Merge active entropy generation updates.

This is admittedly partly "for discussion".  We need to have a way
forward for the boot time deadlocks where user space ends up waiting for
more entropy, but no entropy is forthcoming because the system is
entirely idle just waiting for something to happen.

While this was triggered by what is arguably a user space bug with
GDM/gnome-session asking for secure randomness during early boot, when
they didn't even need any such truly secure thing, the issue ends up
being that our "getrandom()" interface is prone to that kind of
confusion, because people don't think very hard about whether they want
to block for sufficient amounts of entropy.

The approach here-in is to decide to not just passively wait for entropy
to happen, but to start actively collecting it if it is missing.  This
is not necessarily always possible, but if the architecture has a CPU
cycle counter, there is a fair amount of noise in the exact timings of
reasonably complex loads.

We may end up tweaking the load and the entropy estimates, but this
should be at least a reasonable starting point.

As part of this, we also revert the revert of the ext4 IO pattern
improvement that ended up triggering the reported lack of external
entropy.

* getrandom() active entropy waiting:
  Revert "Revert "ext4: make __ext4_get_inode_loc plug""
  random: try to actively add entropy rather than passively wait for it

This reverts commit 72dbcf72.

Instead of waiting forever for entropy that may just not happen, we now
try to actively generate entropy when required, and are thus hopefully
avoiding the problem that caused the nice ext4 IO pattern fix to be
reverted.

So revert the revert.

Cc: Ahmed S. Darwish <darwish.07@gmail.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Alexander E. Patrakov <patrakov@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

For 5.3 we had to revert a nice ext4 IO pattern improvement, because it
caused a bootup regression due to lack of entropy at bootup together
with arguably broken user space that was asking for secure random
numbers when it really didn't need to.

See commit 72dbcf72 (Revert "ext4: make __ext4_get_inode_loc plug").

This aims to solve the issue by actively generating entropy noise using
the CPU cycle counter when waiting for the random number generator to
initialize.  This only works when you have a high-frequency time stamp
counter available, but that's the case on all modern x86 CPU's, and on
most other modern CPU's too.

What we do is to generate jitter entropy from the CPU cycle counter
under a somewhat complex load: calling the scheduler while also
guaranteeing a certain amount of timing noise by also triggering a
timer.

I'm sure we can tweak this, and that people will want to look at other
alternatives, but there's been a number of papers written on jitter
entropy, and this should really be fairly conservative by crediting one
bit of entropy for every timer-induced jump in the cycle counter.  Not
because the timer itself would be all that unpredictable, but because
the interaction between the timer and the loop is going to be.

Even if (and perhaps particularly if) the timer actually happens on
another CPU, the cacheline interaction between the loop that reads the
cycle counter and the timer itself firing is going to add perturbations
to the cycle counter values that get mixed into the entropy pool.

As Thomas pointed out, with a modern out-of-order CPU, even quite simple
loops show a fair amount of hard-to-predict timing variability even in
the absense of external interrupts.  But this tries to take that further
by actually having a fairly complex interaction.

This is not going to solve the entropy issue for architectures that have
no CPU cycle counter, but it's not clear how (and if) that is solvable,
and the hardware in question is largely starting to be irrelevant.  And
by doing this we can at least avoid some of the even more contentious
approaches (like making the entropy waiting time out in order to avoid
the possibly unbounded waiting).

Cc: Ahmed Darwish <darwish.07@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Nicholas Mc Guire <hofrat@opentech.at>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Alexander E. Patrakov <patrakov@gmail.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'fixes-5.4-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into arm/fixes

Fixes for omap variants

Few fixes for ti-sysc interconnect target module driver for no-idle
quirks that caused nfsroot to fail on some dra7 boards.

And let's fixes to get LCD working again for logicpd board that got
broken a while back with removal of panel-dpi driver. We need to now
use generic CONFIG_DRM_PANEL_SIMPLE instead.

* tag 'fixes-5.4-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  bus: ti-sysc: Remove unpaired sysc_clkdm_deny_idle()
  ARM: dts: logicpd-som-lv: Fix i2c2 and i2c3 Pin mux
  ARM: dts: am3517-evm: Fix missing video
  ARM: dts: logicpd-torpedo-baseboard: Fix missing video
  ARM: omap2plus_defconfig: Fix missing video
  bus: ti-sysc: Fix handling of invalid clocks
  bus: ti-sysc: Fix clock handling for no-idle quirks

Link: https://lore.kernel.org/r/pull-1568819401-72461@atomide.comSigned-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'scmi-fixes-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/fixes

ARM SCMI fixes for v5.4

Couple of fixes: one in scmi reset driver initialising missed scmi handle
and an other in scmi reset API implementation fixing the assignment of
reset state

* tag 'scmi-fixes-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  reset: reset-scmi: add missing handle initialisation
  firmware: arm_scmi: reset: fix reset_state assignment in scmi_domain_reset

Link: https://lore.kernel.org/r/20190918142139.GA4370@bogusSigned-off-by: Olof Johansson <olof@lixom.net>

More libnvdimm updates from Dan Williams:

 - Complete the reworks to interoperate with powerpc dynamic huge page
   sizes

 - Fix a crash due to missed accounting for the powerpc 'struct
   page'-memmap mapping granularity

 - Fix badblock initialization for volatile (DRAM emulated) pmem ranges

 - Stop triggering request_key() notifications to userspace when
   NVDIMM-security is disabled / not present

 - Miscellaneous small fixups

* tag 'libnvdimm-fixes-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm/region: Enable MAP_SYNC for volatile regions
  libnvdimm: prevent nvdimm from requesting key when security is disabled
  libnvdimm/region: Initialize bad block for volatile namespaces
  libnvdimm/nfit_test: Fix acpi_handle redefinition
  libnvdimm/altmap: Track namespace boundaries in altmap
  libnvdimm: Fix endian conversion issues 
  libnvdimm/dax: Pick the right alignment default when creating dax devices
  powerpc/book3s64: Export has_transparent_hugepage() related functions.