lwn.git/include/linux/device.h, branch v6.11-rc3

driver core: make [device_]driver_attach take a const *

2024-06-20T10:51:42+00:00

Change device_driver_attach() and driver_attach() to take a const * to struct device driver as neither of them modify the structure at all. Also, for some odd reason, drivers/dma/idxd/compat.c had a duplicate external reference to device_driver_attach(), so remove that to fix up the build, it should never have had that there in the first place. Cc: Rafael J. Wysocki Cc: Fenghua Yu Cc: Dave Jiang Cc: Vinod Koul Cc: Andy Shevchenko Cc: Petr Tesarik Cc: Alexander Lobakin Cc: dmaengine@vger.kernel.org Link: https://lore.kernel.org/r/2024061401-rasping-manger-c385@gregkh Signed-off-by: Greg Kroah-Hartman

Merge tag 'v6.10-rc4' into driver-core-next

2024-06-17T06:33:41+00:00

We need the driver core and sysfs fixes in here to build on top of. Signed-off-by: Greg Kroah-Hartman

driver core: device.h: Group of_node handling declarations and definitions

2024-06-04T16:04:36+00:00

There are a few of_node related APIs defined in the driver core. Group the respective declarations and definitions in the header. There is no functional change. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240531145129.1506733-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

driver core: remove devm_device_add_groups()

2024-06-04T13:53:36+00:00

There is no more in-kernel users of this function, and no driver should ever be using it, so remove it from the kernel. Acked-by: Dmitry Torokhov Acked-by: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20230704131715.44454-8-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

Merge tag 'driver-core-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2024-05-22T19:13:40+00:00

Pull driver core updates from Greg KH: "Here is the small set of driver core and kernfs changes for 6.10-rc1. Nothing major here at all, just a small set of changes for some driver core apis, and minor fixups. Included in here are: - sysfs_bin_attr_simple_read() helper added and used - device_show_string() helper added and used All usages of these were acked by the various maintainers. Also in here are: - kernfs minor cleanup - removed unused functions - typo fix in documentation - pay attention to sysfs_create_link() failures in module.c finally All of these have been in linux-next for a very long time with no reported problems" * tag 'driver-core-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: device property: Fix a typo in the description of device_get_child_node_count() kernfs: mount: Remove unnecessary ‘NULL’ values from knparent scsi: Use device_show_string() helper for sysfs attributes platform/x86: Use device_show_string() helper for sysfs attributes perf: Use device_show_string() helper for sysfs attributes IB/qib: Use device_show_string() helper for sysfs attributes hwmon: Use device_show_string() helper for sysfs attributes driver core: Add device_show_string() helper for sysfs attributes treewide: Use sysfs_bin_attr_simple_read() helper sysfs: Add sysfs_bin_attr_simple_read() helper module: don't ignore sysfs_create_link() failures driver core: Remove unused platform_notify, platform_notify_remove

dma: fix DMA sync for drivers not calling dma_set_mask*()

2024-05-09T17:00:29+00:00

There are several reports that the DMA sync shortcut broke non-coherent devices. dev->dma_need_sync is false after the &device allocation and if a driver didn't call dma_set_mask*(), it will still be false even if the device is not DMA-coherent and thus needs synchronizing. Due to historical reasons, there's still a lot of drivers not calling it. Invert the boolean, so that the sync will be performed by default and the shortcut will be enabled only when calling dma_set_mask*(). Reported-by: Steven Price Closes: https://lore.kernel.org/lkml/010686f5-3049-46a1-8230-7752a1b433ff@arm.com Reported-by: Marek Szyprowski Closes: https://lore.kernel.org/lkml/46160534-5003-4809-a408-6b3a3f4921e9@samsung.com Fixes: f406c8e4b770. ("dma: avoid redundant calls for sync operations") Signed-off-by: Alexander Lobakin Signed-off-by: Christoph Hellwig Tested-by: Steven Price Tested-by: Marek Szyprowski

dma: avoid redundant calls for sync operations

2024-05-07T11:29:53+00:00

Quite often, devices do not need dma_sync operations on x86_64 at least. Indeed, when dev_is_dma_coherent(dev) is true and dev_use_swiotlb(dev) is false, iommu_dma_sync_single_for_cpu() and friends do nothing. However, indirectly calling them when CONFIG_RETPOLINE=y consumes about 10% of cycles on a cpu receiving packets from softirq at ~100Gbit rate. Even if/when CONFIG_RETPOLINE is not set, there is a cost of about 3%. Add dev->need_dma_sync boolean and turn it off during the device initialization (dma_set_mask()) depending on the setup: dev_is_dma_coherent() for the direct DMA, !(sync_single_for_device || sync_single_for_cpu) or the new dma_map_ops flag, %DMA_F_CAN_SKIP_SYNC, advertised for non-NULL DMA ops. Then later, if/when swiotlb is used for the first time, the flag is reset back to on, from swiotlb_tbl_map_single(). On iavf, the UDP trafficgen with XDP_DROP in skb mode test shows +3-5% increase for direct DMA. Suggested-by: Christoph Hellwig # direct DMA shortcut Co-developed-by: Eric Dumazet Signed-off-by: Eric Dumazet Signed-off-by: Alexander Lobakin Signed-off-by: Christoph Hellwig

driver core: Add device_show_string() helper for sysfs attributes

2024-05-04T15:37:03+00:00

For drivers wishing to expose an unsigned long, int or bool at a static memory location in sysfs, the driver core provides ready-made helpers such as device_show_ulong() to be used as ->show() callback. Some drivers need to expose a string and so far they all provide their own ->show() implementation. arch/powerpc/perf/hv-24x7.c went so far as to create a device_show_string() helper but kept it private. Make it public for reuse by other drivers. The pattern seems to be sufficiently frequent to merit a public helper. Add a DEVICE_STRING_ATTR_RO() macro in line with the existing DEVICE_ULONG_ATTR() and similar macros to ease declaration of string attributes. Signed-off-by: Lukas Wunner Acked-by: Michael Ellerman Link: https://lore.kernel.org/r/2e3eaaf2600bb55c0415c23ba301e809403a7aa2.1713608122.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

Merge 6.9-rc5 into driver-core-next

2024-04-23T11:27:43+00:00

We want the kernfs fixes in here as well. Signed-off-by: Greg Kroah-Hartman

driver core: Remove unused platform_notify, platform_notify_remove

2024-03-27T07:01:12+00:00

The "platform_notify" and "platform_notify_remove" hooks have been unused since 00ba9357d189 ("ARM: ixp4xx: Drop custom DMA coherency and bouncing"). Remove "platform_notify" and "platform_notify_remove". No functional change intended. Signed-off-by: Bjorn Helgaas Cc: Heikki Krogerus Cc: Linus Walleij Reviewed-by: Andy Shevchenko Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20240325221409.1457036-1-helgaas@kernel.org Signed-off-by: Greg Kroah-Hartman