There are only a few drivers that do not call
spi_finalize_current_message() in the context of transfer_one_message(),
and even for those cases the completion ctlr->cur_msg_completion is not
needed always. The calls to complete() and wait_for_completion() each
take a spin-lock, which is costly. This patch makes it possible to avoid
those calls in the big majority of cases, by introducing two flags that
with the help of ordering via barriers can avoid using the completion
safely. In case of a race with the context calling
spi_finalize_current_message(), the scheme errs on the safe side and takes
the completion.
The impact of this patch is worth the effort: On a i.MX8MM SoC, the time
the SPI bus is idle between two consecutive calls to spi_sync(), is
reduced from 19.6us to 16.8us... roughly 15%.
Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-12-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch introduces a completion that is completed in
spi_finalize_current_message() and waited for in
__spi_pump_transfer_message(). This way all manipulation of ctlr->cur_msg
is done with the io_mutex held and strictly ordered:
__spi_pump_transfer_message() will not return until
spi_finalize_current_message() is done using ctlr->cur_msg, and its
calling context is only touching ctlr->cur_msg after returning.
Due to this, we can safely drop the spin-locks around ctlr->cur_msg.
Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-11-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
The interaction with the controller message queue and its corresponding
auxiliary flags and variables requires the use of the queue_lock which is
costly. Since spi_sync will transfer the complete message anyway, and not
return until it is finished, there is no need to put the message into the
queue if the queue is empty. This can save a lot of overhead.
As an example of how significant this is, when using the MCP2518FD SPI CAN
controller on a i.MX8MM SoC, the time during which the interrupt line
stays active (during 3 relatively short spi_sync messages), is reduced
from 98us to 72us by this patch.
Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-3-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
On 32 bit systems, the following kernel BUG is hit:
BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
caller is debug_smp_processor_id+0x18/0x24
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc1-00001-g6ae0aec8a366 #181
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Backtrace:
dump_backtrace from show_stack+0x20/0x24
r7:81024ffd r6:00000000 r5:81024ffd r4:60000013
show_stack from dump_stack_lvl+0x60/0x78
dump_stack_lvl from dump_stack+0x14/0x1c
r7:81024ffd r6:80f652de r5:80bec180 r4:819a2500
dump_stack from check_preemption_disabled+0xc8/0xf0
check_preemption_disabled from debug_smp_processor_id+0x18/0x24
r8:8119b7e0 r7:81205534 r6:819f5c00 r5:819f4c00 r4:c083d724
debug_smp_processor_id from __spi_sync+0x78/0x220
__spi_sync from spi_sync+0x34/0x4c
r10:bb7bf4e0 r9:c083d724 r8:00000007 r7:81a068c0 r6:822a83c0 r5:c083d724
r4:819f4c00
spi_sync from spi_mem_exec_op+0x338/0x370
r5:000000b4 r4:c083d910
spi_mem_exec_op from spi_nor_read_id+0x98/0xdc
r10:bb7bf4e0 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:82358040
r4:819f7c40
spi_nor_read_id from spi_nor_detect+0x38/0x114
r7:82358040 r6:00000000 r5:819f7c40 r4:819f7c40
spi_nor_detect from spi_nor_scan+0x11c/0xbec
r10:bb7bf4e0 r9:00000000 r8:00000000 r7:c083da4c r6:00000000 r5:00010101
r4:819f7c40
spi_nor_scan from spi_nor_probe+0x10c/0x2d0
r10:bb7bf4e0 r9:bb7bf4d0 r8:00000000 r7:819f4c00 r6:00000000 r5:00000000
r4:819f7c40
per-cpu access needs to be guarded against preemption.
Fixes: 6598b91b5a ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David Jander <david@protonic.nl>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20220609121334.2984808-1-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
Fixes these "make htmldocs" warnings:
include/linux/spi/spi.h:82: warning: Function parameter or member 'syncp' not described in 'spi_statistics'
include/linux/spi/spi.h:213: warning: Function parameter or member 'pcpu_statistics' not described in 'spi_device'
include/linux/spi/spi.h:676: warning: Function parameter or member 'pcpu_statistics' not described in 'spi_controller'
Fixes: 6598b91b5a ("spi: spi.c: Convert statistics to per-cpu u64_stats_t")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David Jander <david@protonic.nl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220608153309.2899565-1-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
This change gives a dramatic performance improvement in the hot path,
since many costly spin_lock_irqsave() calls can be avoided.
On an i.MX8MM system with a MCP2518FD CAN controller connected via SPI,
the time the driver takes to handle interrupts, or in other words the time
the IRQ line of the CAN controller stays low is mainly dominated by the
time it takes to do 3 relatively short sync SPI transfers. The effect of
this patch is a reduction of this time from 136us down to only 98us.
Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220524091808.2269898-1-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>
Pull driver core updates from Greg KH:
"Here is the set of driver core changes for 5.19-rc1.
Lots of tiny driver core changes and cleanups happened this cycle, but
the two major things are:
- firmware_loader reorganization and additions including the ability
to have XZ compressed firmware images and the ability for userspace
to initiate the firmware load when it needs to, instead of being
always initiated by the kernel. FPGA devices specifically want this
ability to have their firmware changed over the lifetime of the
system boot, and this allows them to work without having to come up
with yet-another-custom-uapi interface for loading firmware for
them.
- physical location support added to sysfs so that devices that know
this information, can tell userspace where they are located in a
common way. Some ACPI devices already support this today, and more
bus types should support this in the future.
Smaller changes include:
- driver_override api cleanups and fixes
- error path cleanups and fixes
- get_abi script fixes
- deferred probe timeout changes.
It's that last change that I'm the most worried about. It has been
reported to cause boot problems for a number of systems, and I have a
tested patch series that resolves this issue. But I didn't get it
merged into my tree before 5.18-final came out, so it has not gotten
any linux-next testing.
I'll send the fixup patches (there are 2) as a follow-on series to this
pull request.
All have been tested in linux-next for weeks, with no reported issues
other than the above-mentioned boot time-outs"
* tag 'driver-core-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
driver core: fix deadlock in __device_attach
kernfs: Separate kernfs_pr_cont_buf and rename_lock.
topology: Remove unused cpu_cluster_mask()
driver core: Extend deferred probe timeout on driver registration
MAINTAINERS: add Russ Weight as a firmware loader maintainer
driver: base: fix UAF when driver_attach failed
test_firmware: fix end of loop test in upload_read_show()
driver core: location: Add "back" as a possible output for panel
driver core: location: Free struct acpi_pld_info *pld
driver core: Add "*" wildcard support to driver_async_probe cmdline param
driver core: location: Check for allocations failure
arch_topology: Trace the update thermal pressure
kernfs: Rename kernfs_put_open_node to kernfs_unlink_open_file.
export: fix string handling of namespace in EXPORT_SYMBOL_NS
rpmsg: use local 'dev' variable
rpmsg: Fix calling device_lock() on non-initialized device
firmware_loader: describe 'module' parameter of firmware_upload_register()
firmware_loader: Move definitions from sysfs_upload.h to sysfs.h
firmware_loader: Fix configs for sysfs split
selftests: firmware: Add firmware upload selftests
...
Pull MTD updates from Miquel Raynal:
"There has been a lot of activity in the MTD subsystem recently, with a
number of SPI-NOR cleanups as well as the introduction of ECC engines
that can be used by SPI controllers (hence a few SPI patches in here).
Core MTD changes:
- Replace the expert mode symbols with a single helper
- Fix misuses of of_match_ptr()
- Remove partid and partname debugfs files
- tests: Fix eraseblock read speed miscalculation for lower partition
sizes
- TRX parser: Allow to use on MediaTek MIPS SoCs
MTD driver changes:
- spear_smi: use GFP_KERNEL
- mchp48l640: Add SPI ID table
- mchp23k256: Add SPI ID table
- blkdevs: Avoid soft lockups with some mtd/spi devices
- aspeed-smc: Improve probe resilience
Hyperbus changes:
- HBMC_AM654 should depend on ARCH_K3
NAND core changes:
- ECC:
- Add infrastructure to support hardware engines
- Add a new helper to retrieve the ECC context
- Provide a helper to retrieve a pilelined engine device
NAND-ECC changes:
- Macronix ECC engine:
- Add Macronix external ECC engine support
- Support SPI pipelined mode
- Make two read-only arrays static const
- Fix compile test issue
Raw NAND core changes:
- Fix misuses of of_match_node()
- Rework of_get_nand_bus_width()
- Remove of_get_nand_on_flash_bbt() wrapper
- Protect access to rawnand devices while in suspend
- bindings: Document the wp-gpios property
Rax NAND controller driver changes:
- atmel: Fix refcount issue in atmel_nand_controller_init
- nandsim:
- Add NS_PAGE_BYTE_SHIFT macro to replace the repeat pattern
- Merge repeat codes in ns_switch_state
- Replace overflow check with kzalloc to single kcalloc
- rockchip: Fix platform_get_irq.cocci warning
- stm32_fmc2: Add NAND Write Protect support
- pl353: Set the nand chip node as the flash node
- brcmnand: Fix sparse warnings in bcma_nand
- omap_elm: Remove redundant variable 'errors'
- gpmi:
- Support fast edo timings for mx28
- Validate controller clock rate
- Fix controller timings setting
- brcmnand:
- Add BCMA shim
- BCMA controller uses command shift of 0
- Allow platform data instantation
- Add platform data structure for BCMA
- Allow working without interrupts
- Move OF operations out of brcmnand_init_cs()
- Avoid pdev in brcmnand_init_cs()
- Allow SoC to provide I/O operations
- Assign soc as early as possible
Onenand changes:
- Check for error irq
SPI-NAND core changes:
- Delay a little bit the dirmap creation
- Create direct mapping descriptors for ECC operations
SPI-NAND driver changes:
- macronix: Use random program load
SPI NOR core changes:
- Move vendor specific code out of the core into vendor drivers.
- Unify all function and object names in the vendor modules.
- Make setup() callback optional to improve readability.
- Skip erase logic when the SPI_NOR_NO_ERASE flag is set at flash
declaration.
SPI changes:
- Macronix SPI controller:
- Fix the transmit path
- Create a helper to configure the controller before an operation
- Create a helper to ease the start of an operation
- Add support for direct mapping
- Add support for pipelined ECC operations
- spi-mem:
- Introduce a capability structure
- Check the controller extra capabilities
- cadence-quadspi/mxic: Provide capability structures
- Kill the spi_mem_dtr_supports_op() helper
- Add an ecc parameter to the spi_mem_op structure
Binding changes:
- Dropped mtd/cortina,gemini-flash.txt
- Convert BCM47xx partitions to json-schema
- Vendor prefixes: Clarify Macronix prefix
- SPI NAND: Convert spi-nand description file to yaml
- Raw NAND chip: Create a NAND chip description
- Raw NAND controller:
- Harmonize the property types
- Fix a comment in the examples
- Fix the reg property description
- Describe Macronix NAND ECC engine
- Macronix SPI controller:
- Document the nand-ecc-engine property
- Convert to yaml
- The interrupt property is not mandatory"
* tag 'mtd/changes-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux: (104 commits)
mtd: nand: ecc: mxic: Fix compile test issue
mtd: nand: mxic-ecc: make two read-only arrays static const
mtd: hyperbus: HBMC_AM654 should depend on ARCH_K3
mtd: core: Remove partid and partname debugfs files
dt-bindings: mtd: partitions: convert BCM47xx to the json-schema
mtd: tests: Fix eraseblock read speed miscalculation for lower partition sizes
mtd: rawnand: atmel: fix refcount issue in atmel_nand_controller_init
mtd: rawnand: rockchip: fix platform_get_irq.cocci warning
mtd: spi-nor: Skip erase logic when SPI_NOR_NO_ERASE is set
mtd: spi-nor: renumber flags
mtd: spi-nor: slightly change code style in spi_nor_sr_ready()
mtd: spi-nor: spansion: rename vendor specific functions and defines
mtd: spi-nor: spansion: convert USE_CLSR to a manufacturer flag
mtd: spi-nor: move all spansion specifics into spansion.c
mtd: spi-nor: spansion: slightly rework control flow in late_init()
mtd: spi-nor: micron-st: rename vendor specific functions and defines
mtd: spi-nor: micron-st: convert USE_FSR to a manufacturer flag
mtd: spi-nor: move all micron-st specifics into micron-st.c
mtd: spi-nor: xilinx: correct the debug message
mtd: spi-nor: xilinx: rename vendor specific functions and defines
...
Commit d40f0b6f2e instroduced last_cs_enable to avoid setting
chipselect if it's not necessary, but it also introduces a bug. The
chipselect may not be set correctly on multi-device SPI busses. The
reason is that we can't judge the chipselect by bool last_cs_enable,
since chipselect may be modified after other devices were accessed.
So we should record the specific state of chipselect in case of
confusion.
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Link: https://lore.kernel.org/r/20220217141234.72737-1-yun.zhou@windriver.com
Signed-off-by: Mark Brown <broonie@kernel.org>
All drivers using GPIOs as chip select have been rewritten to use
GPIO descriptors passing the ->use_gpio_descriptors flag. Retire
the code and fields used by the legacy GPIO API.
Do not drop the ->use_gpio_descriptors flag: it now only indicates
that we want to use GPIOs in addition to native chip selects.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220210231954.807904-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Soon the SPI-NAND core will need a way to request a SPI controller to
enable ECC support for a given operation. This is because of the
pipelined integration of certain ECC engines, which are directly managed
by the SPI controller itself.
Introduce a spi_mem_op additional field for this purpose: ecc.
So far this field is left unset and checked to be false by all
the SPI controller drivers in their ->supports_op() hook, as they all
call spi_mem_default_supports_op().
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-7-miquel.raynal@bootlin.com
Merge series from Uwe Kleine-König <u.kleine-koenig@pengutronix.de>:
this series goal is to change the spi remove callback's return value to void.
After numerous patches nearly all drivers already return 0 unconditionally.
The four first patches in this series convert the remaining three drivers to
return 0, the final patch changes the remove prototype and converts all
implementers.
base-commit: 26291c54e1
Merge series from Stefan Binding <sbinding@opensource.cirrus.com>:
This series enhances the helpers for ACPI resources to cope with
multiple resources and exports them for use in the x86 platform code's
multi-instantiate driver.
