uio: uio_dfl: add userspace i/o driver for DFL bus

This patch supports the DFL drivers be written in userspace. This is
realized by exposing the userspace I/O device interfaces.

The driver now only binds the ether group feature, which has no irq. So
the irq support is not implemented yet.

Reviewed-by: Tom Rix <trix@redhat.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/1615168776-8553-2-git-send-email-yilun.xu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/MAINTAINERS b/MAINTAINERS
index aa84121c56117ff16eefb996ade37e586183e985..fca4a9f8f065b0569f35c629f730d993d2ac0d7a 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6992,6 +6992,7 @@ S:        Maintained
 F:     Documentation/ABI/testing/sysfs-bus-dfl*
 F:     Documentation/fpga/dfl.rst
 F:     drivers/fpga/dfl*
+F:     drivers/uio/uio_dfl.c
 F:     include/linux/dfl.h
 F:     include/uapi/linux/fpga-dfl.h
 

diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index 202ee81cfc2ba4de6f37ceaa74cecf0a29f0406e..5531f3afeb2130a958ae2d398c9a58eb36c7d9c1 100644 (file)
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -165,4 +165,21 @@ config UIO_HV_GENERIC
          to network and storage devices from userspace.
 
          If you compile this as a module, it will be called uio_hv_generic.
+
+config UIO_DFL
+       tristate "Generic driver for DFL (Device Feature List) bus"
+       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
+
+         It could be found at:
+
+           opae-sdk/tools/libopaeuio/
+
+         If you compile this as a module, it will be called uio_dfl.
 endif

diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
index c285dd2a4539b80fd9b957f5dc5f947d0ac2e04d..f2f416a142286b791be31dc0f0e234b2124e75df 100644 (file)
--- 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 (file)
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");