Re: [PATCH v9 1/2] uio: uio_dfl: add userspace i/o driver for DFL bus

[Tom Rix <trix@redhat.com>]

On 1/25/21 6:22 PM, Moritz Fischer wrote:
> On Mon, Jan 25, 2021 at 11:00:38AM -0800, Tom Rix wrote:
Snip
>>
>>> +	depends on FPGA_DFL
>>> +	help
>>> +	  Generic DFL (Device Feature List) driver for Userspace I/O devices.
>>> +	  It is useful to provide direct access to DFL devices from userspace.
>>> +	  A sample userspace application using this driver is available for
>>> +	  download in a git repository:
>>> +
>>> +	    git clone https://github.com/OPAE/opae-sdk.git
>>> +
>>> +	  If you compile this as a module, it will be called uio_dfl.
> I'm not sure KConfig is the right place for this.

More than half of the other configs do this.

ex/

config UIO_MF624
    tristate "Humusoft MF624 DAQ PCI card driver"
    depends on PCI
    help
      Userspace I/O interface for the Humusoft MF624 PCI card.
      A sample userspace application using this driver is available
      (among other MF624 related information and software components)
      for download in a git repository:

        git clone git://rtime.felk.cvut.cz/mf6xx.git

      If you compile this as a module, it will be called uio_mf624.

Tom

>> opae-sdk is pretty large and uncovered in the Documentation/fpga/dfl.rst.
>>
>> Where in opae-sdk is this example ?
>>
>> If you can point me at the example, I will turn it into a selftest.
>>
>> Tom
>>
>>>  endif
>>> diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
>>> index c285dd2..f2f416a1 100644
>>> --- a/drivers/uio/Makefile
>>> +++ b/drivers/uio/Makefile
>>> @@ -11,3 +11,4 @@ obj-$(CONFIG_UIO_PRUSS)         += uio_pruss.o
>>>  obj-$(CONFIG_UIO_MF624)         += uio_mf624.o
>>>  obj-$(CONFIG_UIO_FSL_ELBC_GPCM)	+= uio_fsl_elbc_gpcm.o
>>>  obj-$(CONFIG_UIO_HV_GENERIC)	+= uio_hv_generic.o
>>> +obj-$(CONFIG_UIO_DFL)	+= uio_dfl.o
>>> diff --git a/drivers/uio/uio_dfl.c b/drivers/uio/uio_dfl.c
>>> new file mode 100644
>>> index 0000000..89c0fc7
>>> --- /dev/null
>>> +++ b/drivers/uio/uio_dfl.c
>>> @@ -0,0 +1,66 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * Generic DFL driver for Userspace I/O devicess
>>> + *
>>> + * Copyright (C) 2021 Intel Corporation, Inc.
>>> + */
>>> +#include <linux/dfl.h>
>>> +#include <linux/errno.h>
>>> +#include <linux/module.h>
>>> +#include <linux/uio_driver.h>
>>> +
>>> +#define DRIVER_NAME "uio_dfl"
>>> +
>>> +static int uio_dfl_probe(struct dfl_device *ddev)
>>> +{
>>> +	struct resource *r = &ddev->mmio_res;
>>> +	struct device *dev = &ddev->dev;
>>> +	struct uio_info *uioinfo;
>>> +	struct uio_mem *uiomem;
>>> +	int ret;
>>> +
>>> +	uioinfo = devm_kzalloc(dev, sizeof(struct uio_info), GFP_KERNEL);
>>> +	if (!uioinfo)
>>> +		return -ENOMEM;
>>> +
>>> +	uioinfo->name = DRIVER_NAME;
>>> +	uioinfo->version = "0";
>>> +
>>> +	uiomem = &uioinfo->mem[0];
>>> +	uiomem->memtype = UIO_MEM_PHYS;
>>> +	uiomem->addr = r->start & PAGE_MASK;
>>> +	uiomem->offs = r->start & ~PAGE_MASK;
>>> +	uiomem->size = (uiomem->offs + resource_size(r)
>>> +			+ PAGE_SIZE - 1) & PAGE_MASK;
>>> +	uiomem->name = r->name;
>>> +
>>> +	/* Irq is yet to be supported */
>>> +	uioinfo->irq = UIO_IRQ_NONE;
>>> +
>>> +	ret = devm_uio_register_device(dev, uioinfo);
>>> +	if (ret)
>>> +		dev_err(dev, "unable to register uio device\n");
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +#define FME_FEATURE_ID_ETH_GROUP	0x10
>>> +
>>> +static const struct dfl_device_id uio_dfl_ids[] = {
>>> +	{ FME_ID, FME_FEATURE_ID_ETH_GROUP },
>>> +	{ }
>>> +};
>>> +MODULE_DEVICE_TABLE(dfl, uio_dfl_ids);
>>> +
>>> +static struct dfl_driver uio_dfl_driver = {
>>> +	.drv = {
>>> +		.name = DRIVER_NAME,
>>> +	},
>>> +	.id_table	= uio_dfl_ids,
>>> +	.probe		= uio_dfl_probe,
>>> +};
>>> +module_dfl_driver(uio_dfl_driver);
>>> +
>>> +MODULE_DESCRIPTION("Generic DFL driver for Userspace I/O devices");
>>> +MODULE_AUTHOR("Intel Corporation");
>>> +MODULE_LICENSE("GPL v2");