[RESEND PATCH v11 1/2] uio: uio_dfl: add userspace i/o driver for DFL bus

From: Xu Yilun
Date: Sat Feb 27 2021 - 10:34:34 EST


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.

Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
Reviewed-by: Tom Rix <trix@xxxxxxxxxx>
---
v9: switch to add a uio driver in drivers/uio
v10: add the source file in MAINTAINERS
more descriptive Kconfig header
add detailed path for opae uio example
v11: no change
---
MAINTAINERS | 1 +
drivers/uio/Kconfig | 17 +++++++++++++
drivers/uio/Makefile | 1 +
drivers/uio/uio_dfl.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 85 insertions(+)
create mode 100644 drivers/uio/uio_dfl.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 000fe0b..4dc0354 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6943,6 +6943,7 @@ 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 202ee81..5531f3a 100644
--- 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 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");
--
2.7.4