There are numerous places in the kernel that would be sped up by having
smaller batches. Currently those callsites do `get_random_u32() & 0xff`
or similar. Since these are pretty spread out, and will require patches
to multiple different trees, let's get ahead of the curve and lay the
foundation for `get_random_u8()` and `get_random_u16()`, so that it's
then possible to start submitting conversion patches leisurely.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
On some small machines with little entropy, a quasi-unique hostname is
sometimes a relevant factor. I've seen, for example, 8 character
alpha-numeric serial numbers. In addition, the time at which the hostname
is set is usually a decent measurement of how long early boot took. So,
call add_device_randomness() on new hostnames, which feeds its arguments
to the RNG in addition to a fresh cycle counter.
Low cost hooks like this never hurt and can only ever help, and since
this costs basically nothing for an operation that is never a fast path,
this is an overall easy win.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Rather than going through the current-> indirection for utsname, at this
point in boot, init_utsname()==utsname(), so just use it directly that
way. Additionally, init_utsname() appears to be available nearly always,
so move it into random_init_early().
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
As of the prior commit, the RNG will have incorporated both a cycle
counter value and RDRAND, in addition to various other environmental
noise. Therefore, using get_random_u32() will supply a stronger seed
than simply using random_get_entropy(). N.B.: random_get_entropy()
should be considered an internal API of random.c and not generally
consumed.
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
The full RNG initialization relies on some timestamps, made possible
with initialization functions like time_init() and timekeeping_init().
However, these are only available rather late in initialization.
Meanwhile, other things, such as memory allocator functions, make use of
the RNG much earlier.
So split RNG initialization into two phases. We can provide arch
randomness very early on, and then later, after timekeeping and such are
available, initialize the rest.
This ensures that, for example, slabs are properly randomized if RDRAND
is available. Without this, CONFIG_SLAB_FREELIST_RANDOM=y loses a degree
of its security, because its random seed is potentially deterministic,
since it hasn't yet incorporated RDRAND. It also makes it possible to
use a better seed in kfence, which currently relies on only the cycle
counter.
Another positive consequence is that on systems with RDRAND, running
with CONFIG_WARN_ALL_UNSEEDED_RANDOM=y results in no warnings at all.
One subtle side effect of this change is that on systems with no RDRAND,
RDTSC is now only queried by random_init() once, committing the moment
of the function call, instead of multiple times as before. This is
intentional, as the multiple RDTSCs in a loop before weren't
accomplishing very much, with jitter being better provided by
try_to_generate_entropy(). Plus, filling blocks with RDTSC is still
being done in extract_entropy(), which is necessarily called before
random bytes are served anyway.
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
PCIe r6.0, sec 5.9, requires a 10ms delay between programming a device to
change to or from D3hot and the time the device is next accessed (unless
Readiness Notifications are used).
The 10ms value (PCI_PM_D3HOT_WAIT) doesn't appear directly here because
some chipsets require 120ms for devices *below* them (pci_pm_d3hot_delay)
and some devices require more or less than 10ms (dev->d3hot_delay).
But msleep(10) typically waits about *20*ms, which is more than we need.
Switch to usleep_range() to improve the delay accuracy.
Based on a commit from Sajid in the Pixel 6 kernel tree [1]. On a Pixel 6,
the 10ms delay for the Exynos PCIe device delayed for an average of 19ms.
Switching to usleep_range() decreased the resume time by about 9ms.
[1] 18a8cad68d
[bhelgaas commit log, add timers-howto.rst link]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/timers/timers-howto.rst?id=v5.19#n73
Link: https://lore.kernel.org/r/20220921212735.2131588-1-willmcvicker@google.com
Signed-off-by: Sajid Dalvi <sdalvi@google.com>
Signed-off-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
checkpatch does not point out that VM_BUG_ON() and friends should be
avoided, however, Linus notes:
VM_BUG_ON() has the exact same semantics as BUG_ON. It is literally
no different, the only difference is "we can make the code smaller
because these are less important". [1]
So let's warn on VM_BUG_ON() and other BUG variants as well. While at it,
make it clearer that the kernel really shouldn't be crashed.
As there are some subsystem BUG macros that actually don't end up crashing
the kernel -- for example, KVM_BUG_ON() -- exclude these manually.
[1] https://lore.kernel.org/r/CAHk-=wg40EAZofO16Eviaj7mfqDhZ2gVEbvfsMf6gYzspRjYvw@mail.gmail.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20220923113426.52871-3-david@redhat.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Linus notes [1] that the introduction of new code that uses VM_BUG_ON()
is just as bad as BUG_ON(), because it will crash the kernel on
distributions that enable CONFIG_DEBUG_VM (like Fedora):
VM_BUG_ON() has the exact same semantics as BUG_ON. It is literally
no different, the only difference is "we can make the code smaller
because these are less important". [2]
This resulted in a more generic discussion about usage of BUG() and
friends. While there might be corner cases that still deserve a BUG_ON(),
most BUG_ON() cases should simply use WARN_ON_ONCE() and implement a
recovery path if reasonable:
The only possible case where BUG_ON can validly be used is "I have
some fundamental data corruption and cannot possibly return an
error". [2]
As a very good approximation is the general rule:
"absolutely no new BUG_ON() calls _ever_" [2]
... not even if something really shouldn't ever happen and is merely for
documenting that an invariant always has to hold. However, there are sill
exceptions where BUG_ON() may be used:
If you have a "this is major internal corruption, there's no way we can
continue", then BUG_ON() is appropriate. [3]
There is only one good BUG_ON():
Now, that said, there is one very valid sub-form of BUG_ON():
BUILD_BUG_ON() is absolutely 100% fine. [2]
While WARN will also crash the machine with panic_on_warn set, that's
exactly to be expected:
So we have two very different cases: the "virtual machine with good
logging where a dead machine is fine" - use 'panic_on_warn'. And
the actual real hardware with real drivers, running real loads by
users. [4]
The basic idea is that warnings will similarly get reported by users
and be found during testing. However, in contrast to a BUG(), there is a
way to actually influence the expected behavior (e.g., panic_on_warn)
and to eventually keep the machine alive to extract some debug info.
Ingo notes that not all WARN_ON_ONCE cases need recovery. If we don't ever
expect this code to trigger in any case, recovery code is not really
helpful.
I'd prefer to keep all these warnings 'simple' - i.e. no attempted
recovery & control flow, unless we ever expect these to trigger.
[5]
There have been different rules floating around that were never properly
documented. Let's try to clarify.
[1] https://lkml.kernel.org/r/CAHk-=wiEAH+ojSpAgx_Ep=NKPWHU8AdO3V56BXcCsU97oYJ1EA@mail.gmail.com
[2] https://lore.kernel.org/r/CAHk-=wg40EAZofO16Eviaj7mfqDhZ2gVEbvfsMf6gYzspRjYvw@mail.gmail.com
[3] https://lkml.kernel.org/r/CAHk-=wit-DmhMfQErY29JSPjFgebx_Ld+pnerc4J2Ag990WwAA@mail.gmail.com
[4] https://lore.kernel.org/r/CAHk-=wgF7K2gSSpy=m_=K3Nov4zaceUX9puQf1TjkTJLA2XC_g@mail.gmail.com
[5] https://lore.kernel.org/r/YwIW+mVeZoTOxn%2F4@gmail.com
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20220923113426.52871-2-david@redhat.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Since commit b3ac04132c ("mm/rmap: Turn page_referenced() into
folio_referenced()") the page_referenced function name was modified,
so fix it up to use the correct one.
Signed-off-by: Vernon Yang <vernon2gm@gmail.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/20220926152032.74621-1-vernon2gm@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The Code of Conduct interpretation does not reflect the current
practices of the CoC committee or the TAB. Update the documentation
to remove references to initial committees and boot strap periods
since it is past that time, and note that the this document
does serve as the documentation for the CoC committee processes.
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220926211149.2278214-1-kristen@linux.intel.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Now that building html docs with math expressions does not need texlive
packages, remove the note on the requirement in the "Sphinx Install"
section.
Instead, add sections of "Math Expressions in HTML" and "Choice of Math
Renderer".
Describe the effect of setting SPHINX_IMGMATH in the latter section.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/a67e3279-6bc7-ee2c-2b49-9275252460b0@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Bring the description on when to use the Reported-by: tag found in
Documentation/process/5.Posting.rst more in line with the description in
Documentation/process/submitting-patches.rst: before this change the two
were contradicting each other, as the latter is way more permissive and
only states '[...] if the bug was reported in private, then ask for
permission first before using the Reported-by tag.'
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Link: https://lore.kernel.org/r/2fc7162dfb76e04da5ea903c9c170d913e735dad.1664372256.git.linux@leemhuis.info
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
After commit 22471e1313 ("kconfig: use a menu in arch/Kconfig to reduce
clutter"), the location of Kprobes is under "General architecture-dependent
options" rather than "General setup".
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fixes: 22471e1313 ("kconfig: use a menu in arch/Kconfig to reduce clutter")
Link: https://lore.kernel.org/r/1663322106-12178-1-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
A brown paper bag where -Wno-error=deprecated-declarations was added
from compiler output when the right thing is to add
-Wno-deprecated-declarations, fix it.
Fixes: 4ee3c4da8b ("perf scripting python: Do not build fail on deprecation warnings")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
On K3 SoCs, the power-domains property is needed. On the earlier SoCs,
the power-domains property is handled by the interconnect target module
parent device.
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220919112357.64997-1-tony@atomide.com
Signed-off-by: Rob Herring <robh@kernel.org>
The top-level index.rst file is the entry point for the kernel's
documentation, especially for readers of the HTML output. It is currently
a mess containing everything we thought to throw in there. Firefox says it
would require 26 pages of paper to print it. That is not a user-friendly
introduction.
This series aims to improve our documentation entry point with a focus on
rewriting index.rst. The result is, IMO, simpler and more approachable.
For anybody who wants to see the rendered results without building the
docs, have a look at:
https://static.lwn.net/kerneldoc/
This time around I've rendered the pages using the "Read The Docs" theme,
since that's what everybody will get by default. That theme ignores the
directives regarding the left column, so the results are not as good there.
I have a series proposing a default-theme change in the works, but that's a
separate topic.
This is only a beginning; I think this kind of organizational effort has to
be pushed down into the lower layers of the docs tree itself. But one has
to start somewhere.
Readers looking for user-oriented information may benefit from it.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-8-corbet@lwn.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
These files describe part of the core API, but have never been converted to
RST due to ... let's say local oppposition. So, create a set of
special-purpose wrappers to ..include these files into a separate page so
that they can be a part of the htmldocs build. Then link them into the
core-api manual and remove them from the "staging" dumping ground.
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-7-corbet@lwn.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This one file should not really be in the top-level documentation
directory. core-api/ may not be a perfect fit but seems to be best, so
move it there. Adjust a couple of internal document references to make
them location-independent, and point checkpatch.pl at the new location.
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Joe Perches <joe@perches.com>
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-6-corbet@lwn.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
There is some useless boilerplate text that was added by sphinx when this
file was first created; take it out.
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-5-corbet@lwn.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Use the html_sidebars directive to get a more useful set of links in the
left column.
Unfortunately, this is a no-op with the default RTD theme, but others
observe it.
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-4-corbet@lwn.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The front page is the entry point to the documentation, especially for
people who read it online. It's a big mess of everything we could think to
toss into it. Rewrite the page with an eye toward simplicity and making it
easy for readers to get going toward what they really want to find.
This is only a beginning, but it makes our docs more approachable than
before.
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: David Vernet <void@manifault.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-3-corbet@lwn.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
...otherwise Sphinx won't cooperate when trying to list it explicitly in
the top-level index.rst file
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-2-corbet@lwn.net
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
A clang 15 build reveal several unused-but-set variables, removing the
'foo' variable in tests/mmap-basic.o object to address one of those
cases.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20220929140514.226807-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
clang 15 now warns:
46 65.20 fedora:rawhide : FAIL clang version 15.0.0 (Fedora 15.0.0-3.fc38)
util/parse-events-bison.c:1401:9: error: variable 'parse_events_nerrs' set but not used [-Werror,-Wunused-but-set-variable]
int yynerrs = 0;
^
#define yynerrs parse_events_nerrs
^
1 error generated.
make[3]: *** [/git/perf-6.0.0-rc7/tools/build/Makefile.build:139: util] Error 2
Just ignore one more compiler warning for the bison generated C code.
Committer notes:
Older clangs don't know about -Wunused-but-set-variable, so we need to
add -Wno-unknown-warning-option to avoid this:
37 44.92 fedora:32 : FAIL clang version 10.0.1 (Fedora 10.0.1-3.fc32)
error: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Werror,-Wunknown-warning-option]
make[3]: *** [/git/perf-6.0.0-rc7/tools/build/Makefile.build:139: util] Error 2
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/20220929140514.226807-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
ioat_ring_alloc_order and ioat_ring_max_alloc_order have
been removed since commit cd60cd9613 ("dmaengine: IOATDMA:
Removing descriptor ring reshape"), so remove them.
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20220911091817.3214271-1-cuigaosheng1@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
If the DMA consumer driver does not expect the callback for TX done, then
we need not perform the channel RT byte counter calculations and estimate
the completion but return complete on first attempt itself.This assumes
that the consumer who did not request DMA_PREP_INTERRUPT has its own
mechanism for understanding TX completion, example: MCSPI EOW interrupt
can be used as TX completion signal for a SPI transaction.
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20220914110049.5842-1-vaishnav.a@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine_synchronize implementation is required to synchronize proper
termination of current transfers so that any memory resources are not freed
while still in use.
Implement this callback in the driver so that framework can use the same
(in dmaengine_terminate_sync/ dmaengine_synchronize).
Signed-off-by: Swati Agarwal <swati.agarwal@amd.com>
Link: https://lore.kernel.org/r/20220915090516.5812-1-swati.agarwal@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
qcom,adm require an additional reset for the pbus line. Add this missing
reset to match the current implementation on ipq806x.dtsi.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220914140426.7609-2-ansuelsmth@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Rework the qcom,adm Documentation to yaml schema.
This is not a pure conversion since originally the driver has changed
implementation for the #dma-cells and was wrong from the start.
Also the driver now handles the common DMA clients implementation with
the first cell that denotes the channel number and nothing else since
the client will have to provide the crci information via other means.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220914140426.7609-1-ansuelsmth@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Apple's ADMAC is on all supported Apple silicon SoCs behind an IOMMU
and has its own power-domain.
Signed-off-by: Janne Grunau <j@jannau.net>
Acked-by: Martin Povišer <povik+lin@cutebit.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220916142550.269905-2-j@jannau.net
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Currently, the dw-edma driver enables the runtime_pm for parent device
(chip->dev) and increments/decrements the refcount during alloc/free
chan resources callbacks.
This leads to a problem when the eDMA driver has been probed, but the
channels were not used. This scenario can happen when the DW PCIe driver
probes eDMA driver successfully, but the PCI EPF driver decides not to
use eDMA channels and use iATU instead for PCI transfers.
In this case, the underlying device would be runtime suspended due to
pm_runtime_enable() in dw_edma_probe() and the PCI EPF driver would have
no knowledge of it.
Ideally, the eDMA driver should not be the one doing the runtime PM of
the parent device. The responsibility should instead belong to the client
drivers like PCI EPF.
So let's remove the runtime PM support from eDMA driver.
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220910054700.12205-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add sysfs knob to allow control of the number of batch descriptors that can
be concurrently processed by an engine in the group as a fraction of the
Maximum Work Descriptors in Progress value specfied in ENGCAP register.
This control knob is part of toggle for QoS control.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20220917161222.2835172-6-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add sysfs knob to allow control of the number of work descriptors that can
be concurrently processed by an engine in the group as a fraction of the
Maximum Work Descriptors in Progress value specified in ENGCAP register.
This control knob is part of toggle for QoS control.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20220917161222.2835172-5-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
DSA 2.0 add the capability of configuring DMA ops on a per workqueue basis.
This means that certain ops can be disabled by the system administrator for
certain wq. By default, all ops are available. A bitmap is used to store
the ops due to total op size of 256 bits and it is more convenient to use a
range list to specify which bits are enabled.
One of the usage to support this is for VM migration between different
iteration of devices. The newer ops are disabled in order to allow guest to
migrate to a host that only support older ops. Another usage is to
restrict the WQ to certain operations for QoS of performance.
A sysfs of ops_config attribute is added per wq. It is only usable when the
ops_config bit is set under WQ_CAP register. This means that this attribute
will return -EOPNOTSUPP on DSA 1.x devices. The expected input is a range
list for the bits per operation the WQ supports.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20220917161222.2835172-4-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
To make input and output consistent and prepping for the per WQ operation
configuration support, change the output of opcap display to match the
input that is expected by bitmap_parse() helper function. The output will
be a bitmap with field width as the number of bits using the %*pb format
specifier for printk() family.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20220917161222.2835172-3-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
User reports observing timer event report channel halted but no error
observed in CHANERR register. The driver finished self-test and released
channel resources. Debug shows that __cleanup() can call
mod_timer() after the timer has been deleted and thus resurrect the
timer. While harmless, it causes suprious error message to be emitted.
Use mod_timer_pending() call to prevent deleted timer from being
resurrected.
Fixes: 3372de5813 ("dmaengine: ioatdma: removal of dma_v3.c and relevant ioat3 references")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166360672197.3851724.17040290563764838369.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The calling convention for pre_slave_sg is to return NULL on error and
provide an error log to the system. Qcom-adm instead provide error
pointer when an error occur. This indirectly cause kernel panic for
example for the nandc driver that checks only if the pointer returned by
device_prep_slave_sg is not NULL. Returning an error pointer makes nandc
think the device_prep_slave_sg function correctly completed and makes
the kernel panics later in the code.
While nandc is the one that makes the kernel crash, it was pointed out
that the real problem is qcom-adm not following calling convention for
that function.
To fix this, drop returning error pointer and return NULL with an error
log.
Fixes: 03de6b2738 ("dmaengine: qcom-adm: stop abusing slave_id config")
Fixes: 5c9f8c2dbd ("dmaengine: qcom: Add ADM driver")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Cc: stable@vger.kernel.org # v5.11+
Link: https://lore.kernel.org/r/20220916041256.7104-1-ansuelsmth@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Fix broken slave_config function that uncorrectly compare the
peripheral_size with the size of the config pointer instead of the size
of the config struct. This cause the crci value to be ignored and cause
a kernel panic on any slave that use adm driver.
To fix this, compare to the size of the struct and NOT the size of the
pointer.
Fixes: 03de6b2738 ("dmaengine: qcom-adm: stop abusing slave_id config")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Cc: stable@vger.kernel.org # v5.17+
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220915204844.3838-1-ansuelsmth@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add Coresight to defconfig so that build errors are caught.
CONFIG_CORESIGHT_SOURCE_ETM4X is excluded because it depends on
CONFIG_PID_IN_CONTEXTIDR which has a performance cost.
Signed-off-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20220922142400.478815-2-james.clark@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently we treat any error when reading from the child as a failure and
don't read any more output from that child as a result. This ignores the
fact that it is valid for read() to return EINTR as the error code if there
is a signal pending so we could stop handling the output of children,
especially during exit when we will get some SIGCHLD signals delivered to
us. Fix this by pulling the read handling out into a separate function
which returns a flag if reads should be continued and wrapping it in a
loop.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220921181345.618085-4-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Once we have started exiting the termination handler will have the same
effect as what we're already running so set the termination flag at that
point.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220921181345.618085-3-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When fp-stress gets a termination signal it sets a flag telling itself to
exit and sends a termination signal to all the children. If the flag is set
then don't bother repeating this process, it isn't going to accomplish
anything other than consume CPU time which can be an issue when running in
emulation.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220921181345.618085-2-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Jason A. Donenfeld
Sajid Dalvi
David Hildenbrand
Yang Yingliang
Vernon Yang
Kristen Carlson Accardi
Akira Yokosawa
Thorsten Leemhuis
Tiezhu Yang
Sonny Jiang
Arnaldo Carvalho de Melo
Tony Lindgren
Jonathan Corbet
Jiri Olsa
Andy Shevchenko
Gaosheng Cui
Vaishnav Achath
Swati Agarwal
Christian Marangi
Janne Grunau
Manivannan Sadhasivam
Dave Jiang
James Clark
Mark Brown
Xiu Jianfeng