Small Things:
- Move OpenRISC docs into Documentation and clean them up
- Document previously undocumented devicetree bindings
- Update the or1ksim dts to use stdout-path
OpenRISC SMP support details:
- First the "use shadow registers" and "define CPU_BIG_ENDIAN as true"
get the architecture ready for SMP.
- The "add 1 and 2 byte cmpxchg support" and "use qspinlocks and
qrwlocks" add the SMP locking infrastructure as needed. Using the
qspinlocks and qrwlocks as suggested by Peter Z while reviewing the
original spinlocks implementation.
- The "support for ompic" adds a new irqchip device which is used for
IPI communication to support SMP.
- The "initial SMP support" adds smp.c and makes changes to all of the
necessary data-structures to be per-cpu.
- The remaining patches are bug fixes and debug helpers which I wanted
to keep separate from the "initial SMP support" in order to allow them
to be reviewed on their own. This includes:
- add cacheflush support to fix icache aliasing
- fix initial preempt state for secondary cpu tasks
- sleep instead of spin on secondary wait
- support framepointers and STACKTRACE_SUPPORT
- enable LOCKDEP_SUPPORT and irqflags tracing
- timer sync: Add tick timer sync logic
- fix possible deadlock in timer sync, pointed out by mips guys
Note: the irqchip patch was reviewed with Marc and we agreed to push it
together with these patches.
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Merge tag 'for-linus' of git://github.com/openrisc/linux
Pull OpenRISC updates from Stafford Horne:
"The OpenRISC work is a bit more interesting this time, adding SMP
support and a few general cleanups.
Small Things:
- Move OpenRISC docs into Documentation and clean them up
- Document previously undocumented devicetree bindings
- Update the or1ksim dts to use stdout-path
OpenRISC SMP support details:
- First the "use shadow registers" and "define CPU_BIG_ENDIAN as
true" get the architecture ready for SMP.
- The "add 1 and 2 byte cmpxchg support" and "use qspinlocks and
qrwlocks" add the SMP locking infrastructure as needed. Using the
qspinlocks and qrwlocks as suggested by Peter Z while reviewing the
original spinlocks implementation.
- The "support for ompic" adds a new irqchip device which is used for
IPI communication to support SMP.
- The "initial SMP support" adds smp.c and makes changes to all of
the necessary data-structures to be per-cpu.
The remaining patches are bug fixes and debug helpers which I wanted
to keep separate from the "initial SMP support" in order to allow them
to be reviewed on their own. This includes:
- add cacheflush support to fix icache aliasing
- fix initial preempt state for secondary cpu tasks
- sleep instead of spin on secondary wait
- support framepointers and STACKTRACE_SUPPORT
- enable LOCKDEP_SUPPORT and irqflags tracing
- timer sync: Add tick timer sync logic
- fix possible deadlock in timer sync, pointed out by mips guys
Note: the irqchip patch was reviewed with Marc and we agreed to push
it together with these patches"
* tag 'for-linus' of git://github.com/openrisc/linux:
openrisc: fix possible deadlock scenario during timer sync
openrisc: pass endianness info to sparse
openrisc: add tick timer multi-core sync logic
openrisc: enable LOCKDEP_SUPPORT and irqflags tracing
openrisc: support framepointers and STACKTRACE_SUPPORT
openrisc: add simple_smp dts and defconfig for simulators
openrisc: add cacheflush support to fix icache aliasing
openrisc: sleep instead of spin on secondary wait
openrisc: fix initial preempt state for secondary cpu tasks
openrisc: initial SMP support
irqchip: add initial support for ompic
dt-bindings: add openrisc to vendor prefixes list
openrisc: use qspinlocks and qrwlocks
openrisc: add 1 and 2 byte cmpxchg support
openrisc: use shadow registers to save regs on exception
dt-bindings: openrisc: Add OpenRISC platform SoC
Documentation: openrisc: Updates to README
Documentation: Move OpenRISC docs out of arch/
MAINTAINERS: Add OpenRISC pic maintainer
openrisc: dts: or1ksim: Add stdout-path
In case timers are not in sync when cpus start (i.e. hot plug / offset
resets) we need to synchronize the secondary cpus internal timer with
the main cpu. This is needed as in OpenRISC SMP there is only one
clocksource registered which reads from the same ttcr register on each
cpu.
This synchronization routine heavily borrows from mips implementation that
does something similar.
Signed-off-by: Stafford Horne <shorne@gmail.com>
For lockdep support a reliable stack trace mechanism is needed. This
patch adds support in OpenRISC for the stacktrace framework, implemented
by a simple unwinder api. The unwinder api supports both framepointer
and basic stack tracing.
The unwinder is now used to replace the stack_dump() implementation as
well. The new traces are inline with other architectures trace format:
Call trace:
[<c0004448>] show_stack+0x3c/0x58
[<c031c940>] dump_stack+0xa8/0xe4
[<c0008104>] __cpu_up+0x64/0x130
[<c000d268>] bringup_cpu+0x3c/0x178
[<c000d038>] cpuhp_invoke_callback+0xa8/0x1fc
[<c000d680>] cpuhp_up_callbacks+0x44/0x14c
[<c000e400>] cpu_up+0x14c/0x1bc
[<c041da60>] smp_init+0x104/0x15c
[<c033843c>] ? kernel_init+0x0/0x140
[<c0415e04>] kernel_init_freeable+0xbc/0x25c
[<c033843c>] ? kernel_init+0x0/0x140
[<c0338458>] kernel_init+0x1c/0x140
[<c003a174>] ? schedule_tail+0x18/0xa0
[<c0006b80>] ret_from_fork+0x1c/0x9c
Signed-off-by: Stafford Horne <shorne@gmail.com>
This patch introduces the SMP support for the OpenRISC architecture.
The SMP architecture requires cores which have multi-core features which
have been introduced a few years back including:
- New SPRS SPR_COREID SPR_NUMCORES
- Shadow SPRs
- Atomic Instructions
- Cache Coherency
- A wired in IPI controller
This patch adds all of the SMP specific changes to core infrastructure,
it looks big but it needs to go all together as its hard to split this
one up.
Boot loader spinning of second cpu is not supported yet, it's assumed
that Linux is booted straight after cpu reset.
The bulk of these changes are trivial changes to refactor to use per cpu
data structures throughout. The addition of the smp.c and changes in
time.c are the changes. Some specific notes:
MM changes
----------
The reason why this is created as an array, and not with DEFINE_PER_CPU
is that doing it this way, we'll save a load in the tlb-miss handler
(the load from __per_cpu_offset).
TLB Flush
---------
The SMP implementation of flush_tlb_* works by sending out a
function-call IPI to all the non-local cpus by using the generic
on_each_cpu() function.
Currently, all flush_tlb_* functions will result in a flush_tlb_all(),
which has always been the behaviour in the UP case.
CPU INFO
--------
This creates a per cpu cpuinfo struct and fills it out accordingly for
each activated cpu. show_cpuinfo is also updated to reflect new version
information in later versions of the spec.
SMP API
-------
This imitates the arm64 implementation by having a smp_cross_call
callback that can be set by set_smp_cross_call to initiate an IPI and a
handle_IPI function that is expected to be called from an IPI irqchip
driver.
Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
[shorne@gmail.com: added cpu stop, checkpatch fixes, wrote commit message]
Signed-off-by: Stafford Horne <shorne@gmail.com>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Idle poller with an extra check_pgt_cache() invocation. Use the core
code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Link: http://lkml.kernel.org/r/20130321215234.886530981@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Same code. Use the generic version. The special Makefile treatment is
pointless anyway as init_task.o contains only data which is handled by
the linker script. So no point on being treated like head text.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jonas Bonn <jonas@southpole.se>
Link: http://lkml.kernel.org/r/20120503085035.083343435@linutronix.de
Linus Torvalds
Stafford Horne
Stefan Kristiansson
Greg Kroah-Hartman
Thomas Gleixner
Al Viro
Jonas Bonn