On Mi, 2020-04-29 at 11:41 +0200, gre...@linuxfoundation.org wrote: > On Wed, Apr 29, 2020 at 07:51:01AM +0000, Stahl, Manuel wrote: > > On Di, 2020-04-28 at 15:54 +0200, gregkh @ linuxfoundation . org wrote: > > > On Thu, Apr 16, 2020 at 06:38:30PM +0200, Manuel Stahl wrote: > > > > > > > > + * > > > > + * Since the driver does not declare any device ids, you must allocate > > > > + * id and bind the device to the driver yourself. For example: > > > > + * > > > > + * # echo "8086 10f5" > /sys/bus/pci/drivers/uio_pci_dmem_genirq/new_id > > > > + * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind > > > > + * # echo -n 0000:00:19.0 > > > > > /sys/bus/pci/drivers/uio_pci_dmem_genirq/bind > > > > + * # ls -l /sys/bus/pci/devices/0000:00:19.0/driver > > > > + * .../0000:00:19.0/driver -> > > > > ../../../bus/pci/drivers/uio_pci_dmem_genirq > > > > + * > > > > + * Or use a modprobe alias: > > > > + * # alias pci:v000010EEd00001000sv*sd*sc*i* uio_pci_dmem_genirq > > > > + * > > > > + * Driver won't bind to devices which do not support the Interrupt > > > > Disable Bit > > > > + * in the command register. All devices compliant to PCI 2.3 (circa > > > > 2002) and > > > > + * all compliant PCI Express devices should support this bit. > > > > + * > > > > + * The DMA mask bits and sizes of dynamic regions are derived from > > > > module > > > > + * parameters. > > > > + * > > > > + * The format for specifying dynamic region sizes in module parameters > > > > + * is as follows: > > > > + * > > > > + * uio_pci_dmem_genirq.dmem_sizes := > > > > <uio_dmem_sizes_def>[;<uio_dmem_sizes_def>] > > > > + * <uio_dmem_sizes_def> := <pci_id>:<size>[,<size>] > > > > + * <pci_id> := <vendor>:<device> > > > > + * <size> := standard linux memsize > > > > + * > > > > + * Examples: > > > > + * > > > > + * 1) UIO dmem device with 3 dynamic regions: > > > > + * uio_pci_dmem_genirq.dmem_sizes=8086:10f5:4K,16K,4M > > > > + * > > > > + * 2) Two UIO dmem devices with different number of dynamic regions: > > > > + * uio_pci_dmem_genirq.dmem_sizes=8086:10f5:4K,16K,4M;1234:0001:8K > > > > > > Module parameters are horrid, are you sure there is no other way? > > > > You're right, seemed to be the simplest solution back when we started > > developing this driver. I will try to change it to sysfs, so that one can > > add regions while the module is already loaded. > > /me hands you some \n characters... > > Anyway, configfs is for configuring stuff, don't make a sysfs file that > you have to somehow "parse" please.
Looking back at this driver after some years I realized again the reason for using kernel parameters: The current UIO API needs the information about available memory maps when registering a new UIO device with __uio_register_device(), which obviously needs to be called during probe() in uio_pci_dmem_genirq. Otherwise there is no device file in /dev to open for user space applications. After that there is no function to update the uio_map info. So we can either keep the module parameters and allocate the DMA memory during probe() or allocate the DMA memory during mmap() and a) replicate parts of uio_dev_add_attributes() in this driver to update sysfs b) add a function in uio.c to allow updates to the uio_map Which way would you go? Best regards, Manuel Stahl _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
