On Tue, Dec 29, 2020 at 06:37:37AM -0800, Tom Rix wrote:
>
> On 12/28/20 6:42 PM, Xu Yilun wrote:
> > This patch supports the DFL drivers be written in userspace. This is
> > realized by exposing the userspace I/O device interfaces.
> >
> > The driver leverages the uio_pdrv_genirq, it adds the uio_pdrv_genirq
> > platform device with the DFL device's resources, and let the generic UIO
> > platform device driver provide support to userspace access to kernel
> > interrupts and memory locations.
> >
> > The driver now supports the ether group feature. To support a new DFL
> > feature been directly accessed via UIO, its feature id should be added to
> > the driver's id_table.
> >
> > Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
> > ---
> > v2: switch to the new matching algorithem. It matches DFL devices which
> > could not be handled by other DFL drivers.
> > refacor the code about device resources filling.
> > fix some comments.
> > v3: split the dfl.c changes out of this patch.
> > some minor fixes
> > v4: drop the idea of a generic matching algorithem, instead we specify
> > each matching device in id_table.
> > to make clear that only one irq is supported, the irq handling code
> > is refactored.
> > ---
> > drivers/fpga/Kconfig | 10 +++++
> > drivers/fpga/Makefile | 1 +
> > drivers/fpga/dfl-uio-pdev.c | 101 ++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 112 insertions(+)
> > create mode 100644 drivers/fpga/dfl-uio-pdev.c
> >
> > diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> > index 5ff9438..61445be 100644
> > --- a/drivers/fpga/Kconfig
> > +++ b/drivers/fpga/Kconfig
> > @@ -203,6 +203,16 @@ config FPGA_DFL_NIOS_INTEL_PAC_N3000
> > the card. It also instantiates the SPI master (spi-altera) for
> > the card's BMC (Board Management Controller).
> >
> > +config FPGA_DFL_UIO_PDEV
> > + tristate "FPGA DFL Driver for Userspace I/O platform devices"
> > + depends on FPGA_DFL && UIO_PDRV_GENIRQ
> > + help
> > + Enable this to allow some DFL drivers be written in userspace. It
> > + adds the uio_pdrv_genirq platform device with the DFL feature's
> > + resources, and lets the generic UIO platform device driver provide
> > + support for userspace access to kernel interrupts and memory
> > + locations.
> > +
> > config FPGA_DFL_PCI
> > tristate "FPGA DFL PCIe Device Driver"
> > depends on PCI && FPGA_DFL
> > diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> > index 18dc9885..8847fe0 100644
> > --- a/drivers/fpga/Makefile
> > +++ b/drivers/fpga/Makefile
> > @@ -45,6 +45,7 @@ dfl-afu-objs := dfl-afu-main.o dfl-afu-region.o dfl-afu-dma-region.o
> > dfl-afu-objs += dfl-afu-error.o
> >
> > obj-$(CONFIG_FPGA_DFL_NIOS_INTEL_PAC_N3000) += dfl-n3000-nios.o
> > +obj-$(CONFIG_FPGA_DFL_UIO_PDEV) += dfl-uio-pdev.o
> >
> > # Drivers for FPGAs which implement DFL
> > obj-$(CONFIG_FPGA_DFL_PCI) += dfl-pci.o
> > diff --git a/drivers/fpga/dfl-uio-pdev.c b/drivers/fpga/dfl-uio-pdev.c
> > new file mode 100644
> > index 0000000..1100434
> > --- /dev/null
> > +++ b/drivers/fpga/dfl-uio-pdev.c
> > @@ -0,0 +1,101 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * DFL driver for Userspace I/O platform devices
> > + *
> > + * Copyright (C) 2020 Intel Corporation, Inc.
> > + */
> > +#include <linux/dfl.h>
> > +#include <linux/errno.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +#include <linux/uio_driver.h>
> > +
> > +#define DRIVER_NAME "dfl-uio-pdev"
> > +
> > +static int dfl_uio_pdev_probe(struct dfl_device *ddev)
> > +{
> > + struct device *dev = &ddev->dev;
> > + struct platform_device_info pdevinfo = { 0 };
> > + struct uio_info uio_pdata = { 0 };
> > + struct platform_device *uio_pdev;
> > + unsigned int num_res = 1;
> > + struct resource *res;
> > +
> > + if (ddev->num_irqs > 1)
> This num_irq check could be combined with the one below.
Yes, I'll change it.
> > + dev_warn(&ddev->dev,
> > + "%d irqs for %s, but UIO only supports the first one\n",
> > + ddev->num_irqs, dev_name(&ddev->dev));
> > +
> > + pdevinfo.name = "uio_pdrv_genirq";
> > +
> > + if (ddev->num_irqs)
> > + num_res++;
> > +
> > + res = kcalloc(num_res, sizeof(*res), GFP_KERNEL);
>
> Since num_res is at most 2, could res be converted to a stack array ?
Yes, I could refactor the code.
Thanks,
Yilun
>
> Reviewed-by: Tom Rix <trix@xxxxxxxxxx>
