The GSP requires some pieces of metadata to boot. These are passed in a
struct which the GSP transfers via DMA. Create this struct and get a
handle to it for future use when booting the GSP.
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Co-developed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251110-gsp_boot-v9-5-8ae4058e3c0e@nvidia.com>
The GSP requires several areas of memory to operate. Each of these have
their own simple embedded page tables. Set these up and map them for DMA
to/from GSP using CoherentAllocation's. Return the DMA handle describing
where each of these regions are for future use when booting GSP.
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Co-developed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251110-gsp_boot-v9-4-8ae4058e3c0e@nvidia.com>
There are times where we need to store a constant value defined as a
larger type (e.g. through a binding) into a smaller type, knowing
that the value will fit. Rust, unfortunately, only provides us with the
`as` operator for that purpose, the use of which is discouraged as it
silently strips data.
Extend the `num` module with functions allowing to perform the
conversion infallibly, at compile time.
Example:
const FOO_VALUE: u32 = 1;
// `FOO_VALUE` fits into a `u8`, so the conversion is valid.
let foo = num::u32_to_u8::<{ FOO_VALUE }>();
We are going to use this feature extensively in Nova.
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
[acourbot@nvidia.com: fix mistake in example pointed out by Mikko.]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251110-gsp_boot-v9-3-8ae4058e3c0e@nvidia.com>
Remove unnecessary semicolons reported by Coccinelle/coccicheck and the
semantic patch at scripts/coccinelle/misc/semicolon.cocci.
This was introduced in commit 3a4a308c069a ("pwm: mediatek: Convert to
waveform API").
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Link: https://patch.msgid.link/20251105214847.1279520-1-nichen@iscas.ac.cn
[ukleinek: Add reference to introducing commit.]
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Introduce driver for PWM module available on EN7581 SoC.
Limitations:
- Only 8 concurrent waveform generators are available for 8 combinations of
duty_cycle and period. Waveform generators are shared between 16 GPIO
pins and 17 SIPO GPIO pins.
- Supports only normal polarity.
- On configuration the currently running period is completed.
- Minimum supported period is 4 ms
- Maximum supported period is 1s
Signed-off-by: Benjamin Larsson <benjamin.larsson@genexis.eu>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Co-developed-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Link: https://patch.msgid.link/20251013103408.14724-1-ansuelsmth@gmail.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Implement the new waveform callbacks which makes the usage of this
hardware more flexible and allows to use it via the pwm character
device.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20251013114258.149260-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Duty steps computation can never end in values higher than
MAX7360_PWM_MAX: remove useless use of min().
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Suggested-by: Uwe Kleine-König <ukleinek@kernel.org>
Link: https://patch.msgid.link/20250924-mdb-max7360-pwm-optimize-v1-1-5959eeed20d8@bootlin.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The function pwm_apply_args() was introduced with the concept of atomic
PWM configuration and needed for drivers not using this concept yet. Now
all drivers are converted accordingly and so no callers are left which
allows to remove this function.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20250922094327.1143944-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Instead of caring to correctly pluralize "PWM device(s)" using
(chip->npwm != 1) ? "s" : ""
or
str_plural(chip->npwm)
just simplify the format to not need a plural-s.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20250926165702.321514-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
The register addresses of ADP5585 and ADP5589 are swapped.
Fixes: 75024f97e8 ("pwm: adp5585: add support for adp5589")
Signed-off-by: Luke Wang <ziniu.wang_1@nxp.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Tested-by: Liu Ying <victor.liu@nxp.com> # ADP5585 PWM
Link: https://patch.msgid.link/20251114065308.2074893-1-ziniu.wang_1@nxp.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
In case of a kernel crash caused by a protection exception, print the
unmodified PSW address as reported by the CPU. The protection exception
handler modifies the PSW address in order to keep fault handling easy,
however that leads to misleading call traces.
Therefore restore the original PSW address before printing it.
Before this change the output in case of a protection exception looks like
this:
Oops: 0004 ilc:2 [#1]SMP
Krnl PSW : 0704c00180000000 000003ffe0b40d78 (sysrq_handle_crash+0x28/0x40)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
...
Krnl Code: 000003ffe0b40d66: e3e0f0980024 stg %r14,152(%r15)
000003ffe0b40d6c: c010fffffff2 larl %r1,000003ffe0b40d50
#000003ffe0b40d72: c0200046b6bc larl %r2,000003ffe1417aea
>000003ffe0b40d78: 92021000 mvi 0(%r1),2
000003ffe0b40d7c: c0e5ffae03d6 brasl %r14,000003ffe0101528
With this change it looks like this:
Oops: 0004 ilc:2 [#1]SMP
Krnl PSW : 0704c00180000000 000003ffe0b40dfc (sysrq_handle_crash+0x2c/0x40)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
...
Krnl Code: 000003ffe0b40dec: c010fffffff2 larl %r1,000003ffe0b40dd0
000003ffe0b40df2: c0200046b67c larl %r2,000003ffe1417aea
*000003ffe0b40df8: 92021000 mvi 0(%r1),2
>000003ffe0b40dfc: c0e5ffae03b6 brasl %r14,000003ffe0101568
000003ffe0b40e02: 0707 bcr 0,%r7
Note that with this change the PSW address points to the instruction behind
the instruction which caused the exception like it is expected for
protection exceptions.
This also replaces the '#' marker in the disassembly with '*', which allows
to distinguish between new and old behavior.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
With adjust_psw_addr() the uprobes code contains more or less a private
__forward_psw() implementation. Switch it to use __forward_psw(), and
remove adjust_psw_addr().
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Similar to __rewind_psw() add the counter part __forward_psw(). This
helps to make code more readable if a PSW address has to be forwarded,
since it is more natural to write
addr = __forward_psw(psw, ilen);
instead of
addr = __rewind_psw(psw, -ilen);
This renames also the ilc parameter of __rewind_psw() to ilen, since
the parameter reflects an instruction length, and not an instruction
length code. Also change the type of ilen from unsigned long to long
so it reflects that lengths can be negative or positive.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The PAI extension 1 control block area is 512 bytes in total.
It currently contains three address pointer which refer to counter
memory blocks followed by a reserved area.
Calculate the reserved area instead of hardcoding its size. This
makes the code more readable and maintainable.
No functional chance.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Suggested-by: Jan Polensky <japo@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Let dump_fault_info() print additional information to make debugging
easier:
Print "FSI" if the access-exception-fetch/store-indication facility is
installed. If it is installed the TEID may also indicate if an exception
happened because of a fetch or a store operation.
Print "SOP", "ESOP-1", or "ESOP-2" depending on the type of the installed
Suppression-on-Protection facility. This also gives additional information
about the validity and meaning of the TEID bits.
The output is changed from something like:
Failing address: 0000000000000000 TEID: 0000000000000803
to
Failing address: 0000000000000000 TEID: 0000000000000803 ESOP-2 FSI
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The comments in do_protection() give the impression that a TEID, where bit
61 is zero, indicates a low address protection exception. This is not
necessarily true, and it depends on the type of Suppression-on-Protection
facility of the machine (see Princples of Operation) what this means.
Rework the comments and the die() message to reflect this. This may also
help to avoid confusion.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
flush_tlb() exists for historic reasons and was never used. Remove it.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Thomas Richter says:
====================
The PAI PMUs pai_crypto and pai_ext both operate on memory
mapped counters supported by z16 and follow on machines.
These memory mapped counters have a lot in common, like:
- validation, installing and removing events
- starting and stopping events
- retrieving counter values
- collecting sample data.
However both PMU drivers have slightly different parameters,
for example:
- different mapped memory size
- different number of supported counters
- different counter numbers and names
- different bits in the CR0 register
- different anchor address in lowcore
Due to these different parameters, two independent
PMUs have been developed. However both PMU drivers
have very much in common and most of the PMU call back
functions look very similar and are sometimes identical.
This patch set combines both independent PMU device drivers
perf_pai_crypto.c and per_pai_ext.c into one device driver.
The new device driver operations on a table which contains
the different parameters and uses common functions for
event operations.
Result is one PAI PMU driver which supports both PMUs.
It is also extendable to support new PAI PMUs.
====================
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Rename perf_pai_crypto.c to perf_pai.c. The new perf_pai.c
contains both PAI device drivers:
- pai_crypto for PAI crypto counter set
- pai_ext for PAI NNPA counter set
The rename reflects this common driver supporting both PMUs.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Combine PAI cryptography and PAI extension (NNPA) PMUs in one driver.
Remove file perf_pai_ext.c and registration of PMU "pai_ext"
from perf_pai_crypto.c.
Includes:
- Shared alloc/free and sched_task handling
- NNPA events with exclude_kernel enforced, exclude_user rejected
- Setup CR0 bits for both PMUs
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Introduce PAI crypto specific event delete function to handle
additional actions to be done at event removal.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Prepare the common PAI PMU driver to handle multiple PMUs.
Convert pai_root into an array indexed by PAI_PMU_IDX(event)
so that per-CPU state becomes per-PMU. Adjust all call sites
accordingly. Rename KMSG_COMPONENT and the s390dbf buffer from
"pai_crypto" to "pai" for consistent naming.
No functional change intended beyond log identifiers.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename paicrypt_copy() to pai_copy() to indicate its common usage.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Add a common usable function pai_stop() for the event on a CPU.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Add a common usable function pai_stop() for the event on a CPU.
Call this common pai_stop() from paicrypt_del().
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Add a common usable function pai_add() for the event on a CPU.
Call this common pai_add() from paicrypt_add().
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Add a common usable function pai_start() to the event on a CPU.
The function expects a PAI PMU specific read function as second
parameter to read out the start value for an event.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Add a common usable function pai_read() to read counter values.
The function expects a PAI PMU specific read function as second
parameter.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Unify naming and logic for PAI PMU drivers to support both PMUs
pai_crypto and pai_ext.
Rename paicrypt_push_sample() to pai_push_sample() to reflect
its common usage. Add detailed comments about invocation context
and scheduler callbacks. Use struct pai_pmu to determine area_size
instead of PAGE_SIZE for counter backup.
Remove obsolete variable paicrypt_cnt.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename paicrypt_have_samples() to pai_have_samples() to reflect
its common usage. No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename paicrypt_getctr() to pai_getctr() to reflect is common
purpose. pai_getctr() now uses pai_pmu table to extract PAI PMU
characteristics such as kernel_offset inside the counter area page.
Also rename paicrypt_have_sample() to pai_have_sample().
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename paicrypt_getdata() to pai_getdata(). Use the PAI PMU
characteristics in the pai_pmu table to determine the number
of counters to be extracted.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename functions
- paicrypt_free() -> pai_free()
- paicrypt_destroy_event() -> pai_destroy_event()
- paicrypt_destroy_event_cpu() -> pai_destroy_event_cpu()
to reflect their future common usage.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rework PAI crypto event initialization. Add a common
function for event initialization. It uses the PAI characteristics
stored in the pai_pmu table instead of hardcoded values.
Enlarge pai_event_valid() to check all event validation aspects.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Create and add a PMU characteristics table to store the parameters
of the PAI crypto PMU. This table contains PMU details such as
- number of available counters
- name of these counters to export to /sysfs
- Size of the memory mapped counter area
- base number of first counter
- etc
Also define a PMU specific initialization function to be called when
a PAI PMU feature is supported. At device driver initialization
test these features and if available use instruction qpaci to
retrieve the number of available counters. Also export these counter
names to /sysfs and register this PMU.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename functions paicrypt_root_alloc() and paicrypt_root_free()
to pai_root_alloc() and pai_root_free().
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename structure paicrypt_root to pai_root.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename structure paicrypt_map to pai_map.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.
Rename structure paicrypt_mapptr to pai_mapptr.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Rename member page in struct paicrypt_map to area. This rename
creates consistent naming for both PMU drivers paicrypto and PMU
paiext. No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The global variable cfm_dbg points to the s390dbf debug buffer.
Rename it to paidbg to better reflect its purpose.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The save_iaa_wq() function unconditionally returns 0, even when an error
is encountered. This prevents the error code from being propagated to the
caller.
Fix this by returning the 'ret' variable, which holds the actual status
of the operations within the function.
Fixes: ea7a5cbb43 ("crypto: iaa - Add Intel IAA Compression Accelerator crypto driver core")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Use max() instead of max_t() since zstd_cstream_workspace_bound() and
zstd_dstream_workspace_bound() already return size_t and casting the
values is unnecessary.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add the __counted_by() compiler attribute to the flexible array member
'wksp' to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.
Use struct_size(), which provides additional compile-time checks for
structures with flexible array members (e.g., __must_be_array()), for
the allocation size for a new 'zstd_ctx' while we're at it.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
syzbot is reporting possibility of deadlock due to sharing lock_class_key
between padata_init_squeues() and padata_init_reorder_list(). This is a
false positive, for these callers initialize different object. Unshare
lock_class_key by embedding __padata_list_init() into these callers.
Reported-by: syzbot+bd936ccd4339cea66e6b@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=bd936ccd4339cea66e6b
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently if a user enqueues a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistency cannot be addressed without refactoring the API.
alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.
This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.
This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:
commit 128ea9f6cc ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566 ("workqueue: Add new WQ_PERCPU flag")
This change adds a new WQ_PERCPU flag to explicitly request alloc_workqueue()
to be per-cpu when WQ_UNBOUND has not been specified.
With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.
Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Acked-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
