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76234 commits

Author SHA1 Message Date
Rajan Vaja
b3ae24c448 firmware: xilinx: Add sysfs to set shutdown scope
The Linux shutdown functionality implemented via PSCI system_off does
not include an option to set a scope, i.e. which parts of the system to
shut down.

This patch creates sysfs that allows to set the shutdown scope for the
next shutdown request. When the next shutdown is performed, the platform
specific portion of PSCI-system_off can use the chosen shutdown scope.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Stefan Krsmanovic <stefan.krsmanovic@aggios.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-25-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:46:54 +02:00
Rajan Vaja
fdd2ed88ca firmware: xilinx: Add system shutdown API interface
Add system shutdown API interface which asks firmware to
perform system shutdown/restart.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-24-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:46:54 +02:00
Rajan Vaja
ae5c961da6 firmware: xilinx: Add sysfs interface
Add firmware-ggs sysfs interface which provides read/write
interface to global storage registers.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-23-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:46:54 +02:00
Rajan Vaja
4f680b72ea firmware: xilinx: Add APIs to read/write GGS/PGGS registers
Add APIs to read/write PGGS and GGS registers.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-22-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:46:54 +02:00
Rajan Vaja
4db8180ffe firmware: xilinx: Remove eemi ops for fpga related APIs
Use direct function call instead of using eemi ops for fpga related
APIs. Also remove eemi ops structure.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-21-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:09 +02:00
Rajan Vaja
bc86f9c546 firmware: xilinx: Remove eemi ops for aes engine
Use direct function call for aes engine instead of using eemi ops.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-20-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:09 +02:00
Rajan Vaja
cbbbda71fe firmware: xilinx: Remove eemi ops for set_requirement
Use direct function call instead of using eemi ops for
set_requirement.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-19-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:09 +02:00
Rajan Vaja
07fb1a4619 firmware: xilinx: Remove eemi ops for release_node
Use direct function call instead of using eemi ops for release_node.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-18-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:09 +02:00
Rajan Vaja
bf8b27ed23 firmware: xilinx: Remove eemi ops for request_node
Use direct function call instead of using eemi ops for request_node.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-17-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:09 +02:00
Rajan Vaja
951d0a97e4 firmware: xilinx: Remove eemi ops for set_suspend_mode
Use direct function call instead of eemi ops for set_suspend_mode.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-16-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:08 +02:00
Rajan Vaja
9474da950d firmware: xilinx: Remove eemi ops for init_finalize
Use direct function call instead of eemi ops for init_finalize.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-15-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:08 +02:00
Rajan Vaja
1b413581fe firmware: xilinx: Remove eemi ops for reset_get_status
Use direct function call instead of using eemi ops for
reset_get_status.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-14-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:08 +02:00
Rajan Vaja
cf23ec3531 firmware: xilinx: Remove eemi ops for reset_assert
Use direct function call instead of using eemi ops for
reset_assert.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-13-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:08 +02:00
Rajan Vaja
426c8d85df firmware: xilinx: Use APIs instead of IOCTLs
Remove IOCTL API and use individual APIs for better readability.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-12-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:08 +02:00
Rajan Vaja
70c0d36462 firmware: xilinx: Remove eemi ops for clock set/get parent
Use direct function call instead of eemi ops for clock set/get parent.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-11-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:08 +02:00
Rajan Vaja
7a1e10621a firmware: xilinx: Remove eemi ops for clock set/get rate
Use direct function call instead of eemi ops for clock set/get rate.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-10-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:07 +02:00
Rajan Vaja
0667a8d144 firmware: xilinx: Remove eemi ops for clock_getdivider
Use direct function call instead of using eemi ops for
clock_getdivider.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-9-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:07 +02:00
Rajan Vaja
fc9fb8fb98 firmware: xilinx: Remove eemi ops for clock_setdivider
Use direct function call instead of using eemi ops for
clock_setdivider.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-8-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:07 +02:00
Rajan Vaja
5e76731dd3 firmware: xilinx: Remove eemi ops for clock_getstate
Use direct function call instead of eemi ops for clock_getstate.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-7-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:07 +02:00
Rajan Vaja
f5ccd54b67 firmware: xilinx: Remove eemi ops for clock_disable
Use direct function call for clock_disable instead using of eemi ops.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-6-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:07 +02:00
Rajan Vaja
3637e84cd2 firmware: xilinx: Remove eemi ops for clock_enable
Use direct function call for clock_enable instead of eemi ops.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-5-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:07 +02:00
Rajan Vaja
6366c1bac3 firmware: xilinx: Remove eemi ops for query_data
Use direct function call for query_data instead of using eemi ops.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-4-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:06 +02:00
Rajan Vaja
21cd93bab9 firmware: xilinx: Remove eemi ops for get_chipid
Use direct function call instead of eemi ops for get_chipid.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-3-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:45:06 +02:00
Rajan Vaja
b9b3a8be28 firmware: xilinx: Remove eemi ops for get_api_version
Use direct function calls instead of using eemi ops. So remove
eemi ops for get_api_version and use direct function call.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.com>
Link: https://lore.kernel.org/r/1587761887-4279-2-git-send-email-jolly.shah@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:38:38 +02:00
Richard Gong
7536ad8dbf firmware: fpga: replace the error codes with the standard ones
The Intel service layer driver has defined error codes for the
specific services, which started from FPGA configuration then RSU
(Remote Status Update).

Intel service layer driver should define the standard error codes
rather than keep adding more error codes for the new services.

The standard error codes will be used by all the clients of Intel service
layer driver.

Replace FPGA and RSU specific error codes with Intel service layer’s
Common error codes.

Signed-off-by: Richard Gong <richard.gong@intel.com>
Link: https://lore.kernel.org/r/1586897274-307-2-git-send-email-richard.gong@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 15:38:37 +02:00
Manivannan Sadhasivam
0c6b20a1d7 bus: mhi: core: Add support for MHI suspend and resume
Add support for MHI suspend and resume states. While at it, the
mhi_notify() function needs to be exported as well.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200427075829.9304-2-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 14:42:32 +02:00
Thierry Reding
501be6c1c7 drm/tegra: Fix SMMU support on Tegra124 and Tegra210
When testing whether or not to enable the use of the SMMU, consult the
supported DMA mask rather than the actually configured DMA mask, since
the latter might already have been restricted.

Fixes: 2d9384ff91 ("drm/tegra: Relax IOMMU usage criteria on old Tegra")
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2020-04-28 11:44:07 +02:00
Christoph Hellwig
767dea211c x86/tboot: Mark tboot static
This structure is only really used in tboot.c.  The only exception
is a single tboot_enabled check, but for that we don't need an inline
function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200428051703.1625952-1-hch@lst.de
2020-04-28 11:05:44 +02:00
Sergei Shtylyov
1f241ad2a0
mtd: spi-nor: fix kernel-doc for spi_nor::spimem
When adding the 'spimem' field to 'struct spi_nor', a grammar mistake
("point" instead of "pointer") was made -- fix it and convert the SPI
acronym to uppercase and fully spell out "memory", while at it...

Fixes: b35b9a1036 ("mtd: spi-nor: Move m25p80 code in spi-nor.c")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
2020-04-28 09:55:50 +03:00
Sergei Shtylyov
80cb801144
mtd: spi-nor: fix kernel-doc for spi_nor::info
When adding the 'info' field to 'struct spi_nor', some acronyms were in
lower case and some in upper case and the JEDEC acronym mistyped -- fix
these issues.

Fixes: 46dde01f6b ("mtd: spi-nor: add spi_nor_init() function")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
2020-04-28 09:55:29 +03:00
Sergei Shtylyov
ba053dd3b4
mtd: spi-nor: fix kernel-doc for spi_nor::reg_proto
When adding the '{read|write|reg}_proto' fields to 'struct spi_nor', a
colon was missed in the comment for the spi_nor::reg_proto' -- add it.

Fixes: cfc5604c48 ("mtd: spi-nor: introduce SPI 1-2-2 and SPI 1-4-4 protocols")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
2020-04-28 09:45:05 +03:00
Sergei Shtylyov
ba0aa311b0
mtd: spi-nor: fix kernel-doc for spi_nor::mtd
When embedding 'struct mtd_info' within 'struct spi_nor', the kernel-doc
comment was forgotten. Fix it by dropping the "pointer to" part from the
comment.

Fixes: 1976367173 ("mtd: spi-nor: embed struct mtd_info within struct spi_nor")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
2020-04-28 09:45:04 +03:00
Sergei Shtylyov
40a571bc40
mtd: spi-nor: fix kernel-doc for 'struct spi_nor'
When introducing 'struct spi_nor', a number of issues was added in its
kernel-doc comment:

- double article in the heading kernel-doc comment;
- "point" instead of "pointer" for the 'mtd' and 'dev' fields;
- "a" articles instead of "an" for the 'dev' field;
- acronyms in the lower case for the 'dev' field;
- missing "pointer to" for the 'priv' field.

Fix all of those at once...

Fixes: 6e602ef733 ("mtd: spi-nor: add the basic data structures")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
2020-04-28 09:45:04 +03:00
Akash Asthana
e145d9a184 interconnect: Add devm_of_icc_get() as exported API for users
Users can use devm version of of_icc_get() to benefit from automatic
resource release.

Signed-off-by: Akash Asthana <akashast@codeaurora.org>
Reviewed by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1586946198-13912-2-git-send-email-akashast@codeaurora.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
2020-04-27 21:44:33 +03:00
Horatiu Vultur
4b8d7d4c59 bridge: mrp: Extend bridge interface
To integrate MRP into the bridge, first the bridge needs to be aware of ports
that are part of an MRP ring and which rings are on the bridge.
Therefore extend bridge interface with the following:
- add new flag(BR_MPP_AWARE) to the net bridge ports, this bit will be
  set when the port is added to an MRP instance. In this way it knows if
  the frame was received on MRP ring port
- add new flag(BR_MRP_LOST_CONT) to the net bridge ports, this bit will be set
  when the port lost the continuity of MRP Test frames.
- add a list of MRP instances

Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-27 11:40:25 -07:00
Randy Dunlap
be44ae6243 locktorture.c: Fix if-statement empty body warnings
When using -Wextra, gcc complains about torture_preempt_schedule()
when its definition is empty (i.e., when CONFIG_PREEMPTION is not
set/enabled).  Fix these warnings by adding an empty do-while block
for that macro when CONFIG_PREEMPTION is not set.
Fixes these build warnings:

../kernel/locking/locktorture.c:119:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../kernel/locking/locktorture.c:166:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../kernel/locking/locktorture.c:337:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../kernel/locking/locktorture.c:490:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../kernel/locking/locktorture.c:528:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../kernel/locking/locktorture.c:553:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]

I have verified that there is no object code change (with gcc 7.5.0).

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: "Paul E. McKenney" <paulmck@kernel.org>
2020-04-27 11:05:13 -07:00
Paul E. McKenney
9ae58d7bd1 rcu-tasks: Add Kconfig option to mediate smp_mb() vs. IPI
This commit provides a new TASKS_TRACE_RCU_READ_MB Kconfig option that
enables use of read-side memory barriers by both rcu_read_lock_trace()
and rcu_read_unlock_trace() when the are executed with the
current->trc_reader_special.b.need_mb flag set.  This flag is currently
never set.  Doing that is the subject of a later commit.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:03:52 -07:00
Paul E. McKenney
276c410448 rcu-tasks: Split ->trc_reader_need_end
This commit splits ->trc_reader_need_end by using the rcu_special union.
This change permits readers to check to see if a memory barrier is
required without any added overhead in the common case where no such
barrier is required.  This commit also adds the read-side checking.
Later commits will add the machinery to properly set the new
->trc_reader_special.b.need_mb field.

This commit also makes rcu_read_unlock_trace_special() tolerate nested
read-side critical sections within interrupt and NMI handlers.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:03:52 -07:00
Paul E. McKenney
43766c3ead rcu-tasks: Make RCU Tasks Trace make use of RCU scheduler hooks
This commit makes the calls to rcu_tasks_qs() detect and report
quiescent states for RCU tasks trace.  If the task is in a quiescent
state and if ->trc_reader_checked is not yet set, the task sets its own
->trc_reader_checked.  This will cause the grace-period kthread to
remove it from the holdout list if it still remains there.

[ paulmck: Fix conditional compilation per kbuild test robot feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:03:52 -07:00
Paul E. McKenney
d5f177d35c rcu-tasks: Add an RCU Tasks Trace to simplify protection of tracing hooks
Because RCU does not watch exception early-entry/late-exit, idle-loop,
or CPU-hotplug execution, protection of tracing and BPF operations is
needlessly complicated.  This commit therefore adds a variant of
Tasks RCU that:

o	Has explicit read-side markers to allow finite grace periods in
	the face of in-kernel loops for PREEMPT=n builds.  These markers
	are rcu_read_lock_trace() and rcu_read_unlock_trace().

o	Protects code in the idle loop, exception entry/exit, and
	CPU-hotplug code paths.  In this respect, RCU-tasks trace is
	similar to SRCU, but with lighter-weight readers.

o	Avoids expensive read-side instruction, having overhead similar
	to that of Preemptible RCU.

There are of course downsides:

o	The grace-period code can send IPIs to CPUs, even when those
	CPUs are in the idle loop or in nohz_full userspace.  This is
	mitigated by later commits.

o	It is necessary to scan the full tasklist, much as for Tasks RCU.

o	There is a single callback queue guarded by a single lock,
	again, much as for Tasks RCU.  However, those early use cases
	that request multiple grace periods in quick succession are
	expected to do so from a single task, which makes the single
	lock almost irrelevant.  If needed, multiple callback queues
	can be provided using any number of schemes.

Perhaps most important, this variant of RCU does not affect the vanilla
flavors, rcu_preempt and rcu_sched.  The fact that RCU Tasks Trace
readers can operate from idle, offline, and exception entry/exit in no
way enables rcu_preempt and rcu_sched readers to do so.

The memory ordering was outlined here:
https://lore.kernel.org/lkml/20200319034030.GX3199@paulmck-ThinkPad-P72/

This effort benefited greatly from off-list discussions of BPF
requirements with Alexei Starovoitov and Andrii Nakryiko.  At least
some of the on-list discussions are captured in the Link: tags below.
In addition, KCSAN was quite helpful in finding some early bugs.

Link: https://lore.kernel.org/lkml/20200219150744.428764577@infradead.org/
Link: https://lore.kernel.org/lkml/87mu8p797b.fsf@nanos.tec.linutronix.de/
Link: https://lore.kernel.org/lkml/20200225221305.605144982@linutronix.de/
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andriin@fb.com>
[ paulmck: Apply feedback from Steve Rostedt and Joel Fernandes. ]
[ paulmck: Decrement trc_n_readers_need_end upon IPI failure. ]
[ paulmck: Fix locking issue reported by rcutorture. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:03:51 -07:00
Paul E. McKenney
c84aad7654 rcu-tasks: Add an RCU-tasks rude variant
This commit adds a "rude" variant of RCU-tasks that has as quiescent
states schedule(), cond_resched_tasks_rcu_qs(), userspace execution,
and (in theory, anyway) cond_resched().  In other words, RCU-tasks rude
readers are regions of code with preemption disabled, but excluding code
early in the CPU-online sequence and late in the CPU-offline sequence.
Updates make use of IPIs and force an IPI and a context switch on each
online CPU.  This variant is useful in some situations in tracing.

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
[ paulmck: Apply EXPORT_SYMBOL_GPL() feedback from Qiujun Huang. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
[ paulmck: Apply review feedback from Steve Rostedt. ]
2020-04-27 11:03:51 -07:00
Paul E. McKenney
5873b8a94e rcu-tasks: Refactor RCU-tasks to allow variants to be added
This commit splits out generic processing from RCU-tasks-specific
processing in order to allow additional flavors to be added.  It also
adds a def_bool TASKS_RCU_GENERIC to enable the common RCU-tasks
infrastructure code.

This is primarily, but not entirely, a code-movement commit.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:03:51 -07:00
Paul E. McKenney
b3d73156b0 rcu: Reinstate synchronize_rcu_mult()
With the advent and likely usage of synchronize_rcu_rude(), there is
again a need to wait on multiple types of RCU grace periods, for
example, call_rcu_tasks() and call_rcu_tasks_rude().  This commit
therefore reinstates synchronize_rcu_mult() in order to allow these
grace periods to be straightforwardly waited on concurrently.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:03:51 -07:00
Paul E. McKenney
2beaf3280e sched/core: Add function to sample state of locked-down task
A running task's state can be sampled in a consistent manner (for example,
for diagnostic purposes) simply by invoking smp_call_function_single()
on its CPU, which may be obtained using task_cpu(), then having the
IPI handler verify that the desired task is in fact still running.
However, if the task is not running, this sampling can in theory be done
immediately and directly.  In practice, the task might start running at
any time, including during the sampling period.  Gaining a consistent
sample of a not-running task therefore requires that something be done
to lock down the target task's state.

This commit therefore adds a try_invoke_on_locked_down_task() function
that invokes a specified function if the specified task can be locked
down, returning true if successful and if the specified function returns
true.  Otherwise this function simply returns false.  Given that the
function passed to try_invoke_on_nonrunning_task() might be invoked with
a runqueue lock held, that function had better be quite lightweight.

The function is passed the target task's task_struct pointer and the
argument passed to try_invoke_on_locked_down_task(), allowing easy access
to task state and to a location for further variables to be passed in
and out.

Note that the specified function will be called even if the specified
task is currently running.  The function can use ->on_rq and task_curr()
to quickly and easily determine the task's state, and can return false
if this state is not to the function's liking.  The caller of the
try_invoke_on_locked_down_task() would then see the false return value,
and could take appropriate action, for example, trying again later or
sending an IPI if matters are more urgent.

It is expected that use cases such as the RCU CPU stall warning code will
simply return false if the task is currently running.  However, there are
use cases involving nohz_full CPUs where the specified function might
instead fall back to an alternative sampling scheme that relies on heavier
synchronization (such as memory barriers) in the target task.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
[ paulmck: Apply feedback from Peter Zijlstra and Steven Rostedt. ]
[ paulmck: Invoke if running to handle feedback from Mathieu Desnoyers. ]
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:03:50 -07:00
Lai Jiangshan
f0bdf6d473 rcu: Remove unused ->rcu_read_unlock_special.b.deferred_qs field
The ->rcu_read_unlock_special.b.deferred_qs field is set to true in
rcu_read_unlock_special() but never set to false.  This is not
particularly useful, so this commit removes this field.

The only possible justification for this field is to ease debugging
of RCU deferred quiscent states, but the combination of the other
->rcu_read_unlock_special fields plus ->rcu_blocked_node and of course
->rcu_read_lock_nesting should cover debugging needs.  And if this last
proves incorrect, this patch can always be reverted, along with the
required setting of ->rcu_read_unlock_special.b.deferred_qs to false
in rcu_preempt_deferred_qs_irqrestore().

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:03:50 -07:00
Paul E. McKenney
6be7436d22 rcu: Add rcu_gp_might_be_stalled()
This commit adds rcu_gp_might_be_stalled(), which returns true if there
is some reason to believe that the RCU grace period is stalled.  The use
case is where an RCU free-memory path needs to allocate memory in order
to free it, a situation that should be avoided where possible.

But where it is necessary, there is always the alternative of using
synchronize_rcu() to wait for a grace period in order to avoid the
allocation.  And if the grace period is stalled, allocating memory to
asynchronously wait for it is a bad idea of epic proportions: Far better
to let others use the memory, because these others might actually be
able to free that memory before the grace period ends.

Thus, rcu_gp_might_be_stalled() can be used to help decide whether
allocating memory on an RCU free path is a semi-reasonable course
of action.

Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:02:50 -07:00
Jonathan Neuschäfer
ddc4659366 Revert "rculist: Describe variadic macro argument in a Sphinx-compatible way"
This reverts commit f452ee096d.

The workaround became unnecessary with commit 43756e347f
("scripts/kernel-doc: Add support for named variable macro arguments").

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-27 11:01:16 -07:00
Stefano Garzarella
a78d163978 vsock/virtio: fix multiple packet delivery to monitoring devices
In virtio_transport.c, if the virtqueue is full, the transmitting
packet is queued up and it will be sent in the next iteration.
This causes the same packet to be delivered multiple times to
monitoring devices.

We want to continue to deliver packets to monitoring devices before
it is put in the virtqueue, to avoid that replies can appear in the
packet capture before the transmitted packet.

This patch fixes the issue, adding a new flag (tap_delivered) in
struct virtio_vsock_pkt, to check if the packet is already delivered
to monitoring devices.

In vhost/vsock.c, we are splitting packets, so we must set
'tap_delivered' to false when we queue up the same virtio_vsock_pkt
to handle the remaining bytes.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-27 10:18:01 -07:00
Dave Jiang
0821009445 dmaengine: fix channel index enumeration
When the channel register code was changed to allow hotplug operations,
dynamic indexing wasn't taken into account. When channels are randomly
plugged and unplugged out of order, the serial indexing breaks. Convert
channel indexing to using IDA tracking in order to allow dynamic
assignment. The previous code does not cause any regression bug for
existing channel allocation besides idxd driver since the hotplug usage
case is only used by idxd at this point.

With this change, the chan->idr_ref is also not needed any longer. We can
have a device with no channels registered due to hot plug. The channel
device release code no longer should attempt to free the dma device id on
the last channel release.

Fixes: e81274cd6b ("dmaengine: add support to dynamic register/unregister of channels")

Reported-by: Yixin Zhang <yixin.zhang@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Tested-by: Yixin Zhang <yixin.zhang@intel.com>
Link: https://lore.kernel.org/r/158679961260.7674.8485924270472851852.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-04-27 21:26:23 +05:30
Chuck Lever
0a8e7b7d08 SUNRPC: Revert 241b1f419f ("SUNRPC: Remove xdr_buf_trim()")
I've noticed that when krb5i or krb5p security is in use,
retransmitted requests are missing the server's duplicate reply
cache. The computed checksum on the retransmitted request does not
match the cached checksum, resulting in the server performing the
retransmitted request again instead of returning the cached reply.

The assumptions made when removing xdr_buf_trim() were not correct.
In the send paths, the upper layer has already set the segment
lengths correctly, and shorting the buffer's content is simply a
matter of reducing buf->len.

xdr_buf_trim() is the right answer in the receive/unwrap path on
both the client and the server. The buffer segment lengths have to
be shortened one-by-one.

On the server side in particular, head.iov_len needs to be updated
correctly to enable nfsd_cache_csum() to work correctly. The simple
buf->len computation doesn't do that, and that results in
checksumming stale data in the buffer.

The problem isn't noticed until there's significant instability of
the RPC transport. At that point, the reliability of retransmit
detection on the server becomes crucial.

Fixes: 241b1f419f ("SUNRPC: Remove xdr_buf_trim()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-04-27 10:58:30 -04:00