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path: root/drivers/base/isa.c
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2017-12-11Merge 4.15-rc3 into driver-core-nextGreg Kroah-Hartman
We want the fixes and changes in here for testing. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07driver core: add SPDX identifiers to all driver core filesGreg Kroah-Hartman
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the driver core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: William Breathitt Gray <vilhelm.gray@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28isa: Prevent NULL dereference in isa_bus driver callbacksWilliam Breathitt Gray
The isa_driver structure for an isa_bus device is stored in the device platform_data member of the respective device structure. This platform_data member may be reset to NULL if isa_driver match callback for the device fails, indicating a device unsupported by the ISA driver. This patch fixes a possible NULL pointer dereference if one of the isa_driver callbacks to attempted for an unsupported device. This error should not occur in practice since ISA devices are typically manually configured and loaded by the users, but we may as well prevent this error from popping up for the 0day testers. Fixes: a5117ba7da37 ("[PATCH] Driver model: add ISA bus") Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Cc: stable <stable@vger.kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-17isa: Call isa_bus_init before dependent ISA bus drivers registerWilliam Breathitt Gray
The isa_bus_init function must be called before drivers which utilize the ISA bus driver are registered. A race condition for initilization exists if device_initcall is used (the isa_bus_init callback is placed in the same initcall level as dependent drivers which use module_init). This patch ensures that isa_bus_init is called first by utilizing postcore_initcall in favor of device_initcall. Fixes: a5117ba7da37 ("[PATCH] Driver model: add ISA bus") Cc: Rene Herman <rene.herman@keyaccess.nl> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2009-04-07dma-mapping: replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24)Yang Hongyang
Replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24) Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06driver core: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-26isa: set 24-bit dma_mask for ISA devicesRene Herman
dma_alloc_coherent() on x86 currently takes a passed in NULL device pointer to mean that it should allocate an ISA compatible (24-bit) buffer which is a bit of a hack. The ALSA ISA drivers are the main consumers of this but have a struct device in fact readily available. For the legacy drivers, this sets the device dma_mask in preparation for using the actual device with the DMA API so as to eventually not need the NULL hack in dma_alloc_coherent(). This does not fix a current bug -- 2.6.26-rc1 stumbled over the NULL hack in dma_alloc_coherent() but this has already been fixed in commit 4a367f3a9dbf2e7ffcee4702203479809236ee6e by Takashi Iwai. Signed-off-by: Rene Herman <rene.herman@gmail.com> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Acked-by: Takashi Iwai <tiwai@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-06-21[PATCH] Driver model: add ISA busRene Herman
During the recent "isa drivers using platform devices" discussion it was pointed out that (ALSA) ISA drivers ran into the problem of not having the option to fail driver load (device registration rather) upon not finding their hardware due to a probe() error not being passed up through the driver model. In the course of that, I suggested a seperate ISA bus might be best; Russell King agreed and suggested this bus could use the .match() method for the actual device discovery. The attached does this. For this old non (generically) discoverable ISA hardware only the driver itself can do discovery so as a difference with the platform_bus, this isa_bus also distributes match() up to the driver. As another difference: these devices only exist in the driver model due to the driver creating them because it might want to drive them, meaning that all device creation has been made internal as well. The usage model this provides is nice, and has been acked from the ALSA side by Takashi Iwai and Jaroslav Kysela. The ALSA driver module_init's now (for oldisa-only drivers) become: static int __init alsa_card_foo_init(void) { return isa_register_driver(&snd_foo_isa_driver, SNDRV_CARDS); } static void __exit alsa_card_foo_exit(void) { isa_unregister_driver(&snd_foo_isa_driver); } Quite like the other bus models therefore. This removes a lot of duplicated init code from the ALSA ISA drivers. The passed in isa_driver struct is the regular driver struct embedding a struct device_driver, the normal probe/remove/shutdown/suspend/resume callbacks, and as indicated that .match callback. The "SNDRV_CARDS" you see being passed in is a "unsigned int ndev" parameter, indicating how many devices to create and call our methods with. The platform_driver callbacks are called with a platform_device param; the isa_driver callbacks are being called with a "struct device *dev, unsigned int id" pair directly -- with the device creation completely internal to the bus it's much cleaner to not leak isa_dev's by passing them in at all. The id is the only thing we ever want other then the struct device * anyways, and it makes for nicer code in the callbacks as well. With this additional .match() callback ISA drivers have all options. If ALSA would want to keep the old non-load behaviour, it could stick all of the old .probe in .match, which would only keep them registered after everything was found to be present and accounted for. If it wanted the behaviour of always loading as it inadvertently did for a bit after the changeover to platform devices, it could just not provide a .match() and do everything in .probe() as before. If it, as Takashi Iwai already suggested earlier as a way of following the model from saner buses more closely, wants to load when a later bind could conceivably succeed, it could use .match() for the prerequisites (such as checking the user wants the card enabled and that port/irq/dma values have been passed in) and .probe() for everything else. This is the nicest model. To the code... This exports only two functions; isa_{,un}register_driver(). isa_register_driver() register's the struct device_driver, and then loops over the passed in ndev creating devices and registering them. This causes the bus match method to be called for them, which is: int isa_bus_match(struct device *dev, struct device_driver *driver) { struct isa_driver *isa_driver = to_isa_driver(driver); if (dev->platform_data == isa_driver) { if (!isa_driver->match || isa_driver->match(dev, to_isa_dev(dev)->id)) return 1; dev->platform_data = NULL; } return 0; } The first thing this does is check if this device is in fact one of this driver's devices by seeing if the device's platform_data pointer is set to this driver. Platform devices compare strings, but we don't need to do that with everything being internal, so isa_register_driver() abuses dev->platform_data as a isa_driver pointer which we can then check here. I believe platform_data is available for this, but if rather not, moving the isa_driver pointer to the private struct isa_dev is ofcourse fine as well. Then, if the the driver did not provide a .match, it matches. If it did, the driver match() method is called to determine a match. If it did _not_ match, dev->platform_data is reset to indicate this to isa_register_driver which can then unregister the device again. If during all this, there's any error, or no devices matched at all everything is backed out again and the error, or -ENODEV, is returned. isa_unregister_driver() just unregisters the matched devices and the driver itself. More global points/questions... - I'm introducing include/linux/isa.h. It was available but is ofcourse a somewhat generic name. Moving more isa stuff over to it in time is ofcourse fine, so can I have it please? :) - I'm using device_initcall() and added the isa.o (dependent on CONFIG_ISA) after the base driver model things in the Makefile. Will this do, or I really need to stick it in drivers/base/init.c, inside #ifdef CONFIG_ISA? It's working fine. Lastly -- I also looked, a bit, into integrating with PnP. "Old ISA" could be another pnp_protocol, but this does not seem to be a good match, largely due to the same reason platform_devices weren't -- the devices do not have a life of their own outside the driver, meaning the pnp_protocol {get,set}_resources callbacks would need to callback into driver -- which again means you first need to _have_ that driver. Even if there's clean way around that, you only end up inventing fake but valid-form PnP IDs and generally catering to the PnP layer without any practical advantages over this very simple isa_bus. The thing I also suggested earlier about the user echoing values into /sys to set up the hardware from userspace first is... well, cute, but a horrible idea from a user standpoint. Comments ofcourse appreciated. Hope it's okay. As said, the usage model is nice at least. Signed-off-by: Rene Herman <rene.herman@keyaccess.nl>