Re: [PATCH V8 XRT Alveo 04/14] fpga: xrt: xrt-lib driver manager

From: Lizhi Hou
Date: Wed Aug 11 2021 - 17:09:21 EST


Hi Moritz,


Did you get a chance to review XRT V9 patchset which has fixes you suggested? Do you have more comments for XRT patches?


Thanks,

Lizhi

On 7/26/21 4:36 PM, Lizhi Hou wrote:
Hi Moritz,


On 07/25/2021 09:15 PM, Moritz Fischer wrote:
On Mon, Jul 19, 2021 at 02:26:18PM -0700, Lizhi Hou wrote:
xrt-lib kernel module infrastructure code to register and manage all
leaf driver modules.

Signed-off-by: Sonal Santan <sonal.santan@xxxxxxxxxx>
Signed-off-by: Max Zhen <max.zhen@xxxxxxxxxx>
Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxxxxx>
Reviewed-by: Tom Rix <trix@xxxxxxxxxx>
---
  drivers/fpga/xrt/include/subdev_id.h          |  39 +++
  drivers/fpga/xrt/include/xdevice.h            | 131 +++++++
  drivers/fpga/xrt/include/xleaf.h              | 205 +++++++++++
  drivers/fpga/xrt/include/xleaf/clkfreq.h      |  21 ++
  drivers/fpga/xrt/include/xleaf/clock.h        |  29 ++
  .../fpga/xrt/include/xleaf/ddr_calibration.h  |  28 ++
  drivers/fpga/xrt/include/xleaf/devctl.h       |  40 +++
  drivers/fpga/xrt/lib/lib-drv.c                | 322 ++++++++++++++++++
  drivers/fpga/xrt/lib/lib-drv.h                |  21 ++
  9 files changed, 836 insertions(+)
  create mode 100644 drivers/fpga/xrt/include/subdev_id.h
  create mode 100644 drivers/fpga/xrt/include/xdevice.h
  create mode 100644 drivers/fpga/xrt/include/xleaf.h
  create mode 100644 drivers/fpga/xrt/include/xleaf/clkfreq.h
  create mode 100644 drivers/fpga/xrt/include/xleaf/clock.h
  create mode 100644 drivers/fpga/xrt/include/xleaf/ddr_calibration.h
  create mode 100644 drivers/fpga/xrt/include/xleaf/devctl.h
  create mode 100644 drivers/fpga/xrt/lib/lib-drv.c
  create mode 100644 drivers/fpga/xrt/lib/lib-drv.h

diff --git a/drivers/fpga/xrt/include/subdev_id.h b/drivers/fpga/xrt/include/subdev_id.h
new file mode 100644
index 000000000000..02df4b939a1b
--- /dev/null
+++ b/drivers/fpga/xrt/include/subdev_id.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *   Cheng Zhen <maxz@xxxxxxxxxx>
+ */
+
+#ifndef _XRT_SUBDEV_ID_H_
+#define _XRT_SUBDEV_ID_H_
+
+/*
+ * Every subdev driver has an ID for others to refer to it. There can be multiple number of
+ * instances of a subdev driver. A <subdev_id, subdev_instance> tuple is a unique identification
+ * of a specific instance of a subdev driver.
+ */
+enum xrt_subdev_id {
+     XRT_SUBDEV_INVALID = 0,
+     XRT_SUBDEV_GRP,
+     XRT_SUBDEV_VSEC,
+     XRT_SUBDEV_VSEC_GOLDEN,
+     XRT_SUBDEV_DEVCTL,
+     XRT_SUBDEV_AXIGATE,
+     XRT_SUBDEV_ICAP,
+     XRT_SUBDEV_TEST,
+     XRT_SUBDEV_MGMT_MAIN,
+     XRT_SUBDEV_QSPI,
+     XRT_SUBDEV_MAILBOX,
+     XRT_SUBDEV_CMC,
+     XRT_SUBDEV_CALIB,
+     XRT_SUBDEV_CLKFREQ,
+     XRT_SUBDEV_CLOCK,
+     XRT_SUBDEV_SRSR,
+     XRT_SUBDEV_UCS,
+     XRT_SUBDEV_NUM, /* Total number of subdevs. */
+     XRT_ROOT = -1, /* Special ID for root driver. */
+};
+
+#endif       /* _XRT_SUBDEV_ID_H_ */
diff --git a/drivers/fpga/xrt/include/xdevice.h b/drivers/fpga/xrt/include/xdevice.h
new file mode 100644
index 000000000000..3afd96989fc5
--- /dev/null
+++ b/drivers/fpga/xrt/include/xdevice.h
@@ -0,0 +1,131 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *    Lizhi Hou <lizhi.hou@xxxxxxxxxx>
+ */
+
+#ifndef _XRT_DEVICE_H_
+#define _XRT_DEVICE_H_
+
+#include <linux/fs.h>
+#include <linux/cdev.h>
+
+#define XRT_MAX_DEVICE_NODES         128
+#define XRT_INVALID_DEVICE_INST (XRT_MAX_DEVICE_NODES + 1)
+
+enum {
+     XRT_DEVICE_STATE_NONE = 0,
+     XRT_DEVICE_STATE_ADDED
+};
+
+/*
+ * struct xrt_device - represent an xrt device on xrt bus
+ *
+ * dev: generic device interface.
+ * id: id of the xrt device.
Shouldn't this document the rest of the members?
Sure. I will add comments as below.

* dev: generic device interface.
* subdev_id: id of the xrt device. See enum xrt_subdev_id.
* name: name of the xrt device.
* instance: instance of the xrt device. The xrt device with same id can have
*           more than 1 instances.
* state: current state of the xrt device.
* num_resources: The total number of resource for the xrt device.
* resource: point to the xrt device resource array.
* sdev_data: private data pointer.


+ */
+struct xrt_device {
+     struct device dev;
+     u32 subdev_id;
+     const char *name;
+     u32 instance;
+     u32 state;
+     u32 num_resources;
+     struct resource *resource;
+     void *sdev_data;
+};
+
+/*
+ * If populated by xrt device driver, infra will handle the mechanics of
+ * char device (un)registration.
+ */
+enum xrt_dev_file_mode {
+     /* Infra create cdev, default file name */
+     XRT_DEV_FILE_DEFAULT = 0,
+     /* Infra create cdev, need to encode inst num in file name */
+     XRT_DEV_FILE_MULTI_INST,
+     /* No auto creation of cdev by infra, leaf handles it by itself */
+     XRT_DEV_FILE_NO_AUTO,
+};
+
+struct xrt_dev_file_ops {
+     const struct file_operations xsf_ops;
+     dev_t xsf_dev_t;
+     const char *xsf_dev_name;
+     enum xrt_dev_file_mode xsf_mode;
+};
+
+/*
+ * this struct define the endpoints belong to the same xrt device
+ */
ep_name: ... etc?
I will add comment as below.

* ep_name: endpoint name
* compat: compatible string

+struct xrt_dev_ep_names {
+     const char *ep_name;
+     const char *compat;
+};
+
+struct xrt_dev_endpoints {
+     struct xrt_dev_ep_names *xse_names;
+     /* minimum number of endpoints to support the subdevice */
+     u32 xse_min_ep;
+};
+
+/*
+ * struct xrt_driver - represent a xrt device driver
+ *
+ * drv: driver model structure.
drv vs driver?
will fix this.
+ * id_table: pointer to table of device IDs the driver is interested in.
+ *           { } member terminated.
?
file_ops?
I will remove 'id_table' and  add comment as below:

* driver: driver model structure.
* subdev_id: id of the xrt device. See enum xrt_subdev_id.
* file_ops: character device name and callbacks.
* probe: mandatory callback for device binding.
* remove: callback for device unbinding.
* leaf_call: callback for servicing other leaf drivers.

+ * probe: mandatory callback for device binding.
+ * remove: callback for device unbinding.
+ */
+struct xrt_driver {
+     struct device_driver driver;
+     u32 subdev_id;
+     struct xrt_dev_file_ops file_ops;
+     struct xrt_dev_endpoints *endpoints;
+
+     /*
+      * Subdev driver callbacks populated by subdev driver.
+      */
+     int (*probe)(struct xrt_device *xrt_dev);
+     void (*remove)(struct xrt_device *xrt_dev);
+     /*
+      * If leaf_call is defined, these are called by other leaf drivers.
+      * Note that root driver may call into leaf_call of a group driver.
+      */
+     int (*leaf_call)(struct xrt_device *xrt_dev, u32 cmd, void *arg);
+};
+
+#define to_xrt_dev(d) container_of(d, struct xrt_device, dev)
+#define to_xrt_drv(d) container_of(d, struct xrt_driver, driver)
+
+static inline void *xrt_get_drvdata(const struct xrt_device *xdev)
+{
+     return dev_get_drvdata(&xdev->dev);
+}
+
+static inline void xrt_set_drvdata(struct xrt_device *xdev, void *data)
+{
+     dev_set_drvdata(&xdev->dev, data);
+}
+
+static inline void *xrt_get_xdev_data(struct device *dev)
+{
+     struct xrt_device *xdev = to_xrt_dev(dev);
+
+     return xdev->sdev_data;
+}
+
+struct xrt_device *
+xrt_device_register(struct device *parent, u32 id,
+                 struct resource *res, u32 res_num,
+                 void *pdata, size_t data_sz);
+void xrt_device_unregister(struct xrt_device *xdev);
+int xrt_register_driver(struct xrt_driver *drv);
+void xrt_unregister_driver(struct xrt_driver *drv);
+void *xrt_get_xdev_data(struct device *dev);
+struct resource *xrt_get_resource(struct xrt_device *xdev, u32 type, u32 num);
+
+#endif /* _XRT_DEVICE_H_ */
diff --git a/drivers/fpga/xrt/include/xleaf.h b/drivers/fpga/xrt/include/xleaf.h
new file mode 100644
index 000000000000..f065fc766e0f
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf.h
@@ -0,0 +1,205 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *    Cheng Zhen <maxz@xxxxxxxxxx>
+ *    Sonal Santan <sonal.santan@xxxxxxxxxx>
+ */
+
+#ifndef _XRT_XLEAF_H_
+#define _XRT_XLEAF_H_
+
+#include <linux/mod_devicetable.h>
+#include "xdevice.h"
+#include "subdev_id.h"
+#include "xroot.h"
+#include "events.h"
+
+/* All subdev drivers should use below common routines to print out msg. */
+#define DEV(xdev)    (&(xdev)->dev)
+#define DEV_PDATA(xdev) \
+     ((struct xrt_subdev_platdata *)xrt_get_xdev_data(DEV(xdev)))
+#define DEV_FILE_OPS(xdev)                           \
+     (&(to_xrt_drv((xdev)->dev.driver))->file_ops)
+#define FMT_PRT(prt_fn, xdev, fmt, args...)          \
+     ({typeof(xdev) (_xdev) = (xdev);                \
+     prt_fn(DEV(_xdev), "%s %s: " fmt,               \
+     DEV_PDATA(_xdev)->xsp_root_name, __func__, ##args); })
+#define xrt_err(xdev, fmt, args...) FMT_PRT(dev_err, xdev, fmt, ##args)
+#define xrt_warn(xdev, fmt, args...) FMT_PRT(dev_warn, xdev, fmt, ##args)
+#define xrt_info(xdev, fmt, args...) FMT_PRT(dev_info, xdev, fmt, ##args)
+#define xrt_dbg(xdev, fmt, args...) FMT_PRT(dev_dbg, xdev, fmt, ##args)
+
+#define XRT_DEFINE_REGMAP_CONFIG(config_name) \
+     static const struct regmap_config config_name = {               \
+             .reg_bits = 32,                                         \
+             .val_bits = 32,                                         \
+             .reg_stride = 4,                                        \
+             .max_register = 0x1000,                                 \
+     }
+
+enum {
+     /* Starting cmd for common leaf cmd implemented by all leaves. */
+     XRT_XLEAF_COMMON_BASE = 0,
+     /* Starting cmd for leaves' specific leaf cmds. */
+     XRT_XLEAF_CUSTOM_BASE = 64,
+};
+
+enum xrt_xleaf_common_leaf_cmd {
+     XRT_XLEAF_EVENT = XRT_XLEAF_COMMON_BASE,
+};
+
+/*
+ * Partially initialized by the parent driver, then, passed in as subdev driver's
+ * platform data when creating subdev driver instance by calling platform
+ * device register API (xrt_device_register_data() or the likes).
+ *
+ * Once device register API returns, platform driver framework makes a copy of
+ * this buffer and maintains its life cycle. The content of the buffer is
+ * completely owned by subdev driver.
+ *
+ * Thus, parent driver should be very careful when it touches this buffer
+ * again once it's handed over to subdev driver. And the data structure
+ * should not contain pointers pointing to buffers that is managed by
+ * other or parent drivers since it could have been freed before platform
+ * data buffer is freed by platform driver framework.
+ */
+struct xrt_subdev_platdata {
+     /*
+      * Per driver instance callback. The xdev points to the instance.
+      * Should always be defined for subdev driver to get service from root.
+      */
+     xrt_subdev_root_cb_t xsp_root_cb;
+     void *xsp_root_cb_arg;
+
+     /* Something to associate w/ root for msg printing. */
+     const char *xsp_root_name;
+
+     /*
+      * Char dev support for this subdev instance.
+      * Initialized by subdev driver.
+      */
+     struct cdev xsp_cdev;
+     struct device *xsp_sysdev;
+     struct mutex xsp_devnode_lock; /* devnode lock */
+     struct completion xsp_devnode_comp;
+     int xsp_devnode_ref;
+     bool xsp_devnode_online;
+     bool xsp_devnode_excl;
+
+     /*
+      * Subdev driver specific init data. The buffer should be embedded
+      * in this data structure buffer after dtb, so that it can be freed
+      * together with platform data.
+      */
+     loff_t xsp_priv_off; /* Offset into this platform data buffer. */
+     size_t xsp_priv_len;
+
+     /*
+      * Populated by parent driver to describe the device tree for
+      * the subdev driver to handle. Should always be last one since it's
+      * of variable length.
+      */
+     bool xsp_dtb_valid;
+     char xsp_dtb[0];
+};
+
+struct subdev_match_arg {
+     enum xrt_subdev_id id;
+     int instance;
+};
+
+bool xleaf_has_endpoint(struct xrt_device *xdev, const char *endpoint_name);
+struct xrt_device *xleaf_get_leaf(struct xrt_device *xdev,
+                               xrt_subdev_match_t cb, void *arg);
+
+static inline bool subdev_match(enum xrt_subdev_id id, struct xrt_device *xdev, void *arg)
+{
+     const struct subdev_match_arg *a = (struct subdev_match_arg *)arg;
+     int instance = a->instance;
+
+     if (id != a->id)
+             return false;
+     if (instance != xdev->instance && instance != XRT_INVALID_DEVICE_INST)
+             return false;
+     return true;
+}
+
+static inline bool xrt_subdev_match_epname(enum xrt_subdev_id id,
+                                        struct xrt_device *xdev, void *arg)
+{
+     return xleaf_has_endpoint(xdev, arg);
+}
+
+static inline struct xrt_device *
+xleaf_get_leaf_by_id(struct xrt_device *xdev,
+                  enum xrt_subdev_id id, int instance)
+{
+     struct subdev_match_arg arg = { id, instance };
+
+     return xleaf_get_leaf(xdev, subdev_match, &arg);
+}
+
+static inline struct xrt_device *
+xleaf_get_leaf_by_epname(struct xrt_device *xdev, const char *name)
+{
+     return xleaf_get_leaf(xdev, xrt_subdev_match_epname, (void *)name);
+}
+
+static inline int xleaf_call(struct xrt_device *tgt, u32 cmd, void *arg)
+{
+     return (to_xrt_drv(tgt->dev.driver)->leaf_call)(tgt, cmd, arg);
+}
+
+int xleaf_broadcast_event(struct xrt_device *xdev, enum xrt_events evt, bool async);
+int xleaf_create_group(struct xrt_device *xdev, char *dtb);
+int xleaf_destroy_group(struct xrt_device *xdev, int instance);
+void xleaf_get_root_res(struct xrt_device *xdev, u32 region_id, struct resource **res);
+void xleaf_get_root_id(struct xrt_device *xdev, unsigned short *vendor, unsigned short *device,
+                    unsigned short *subvendor, unsigned short *subdevice);
+void xleaf_hot_reset(struct xrt_device *xdev);
+int xleaf_put_leaf(struct xrt_device *xdev, struct xrt_device *leaf);
+struct device *xleaf_register_hwmon(struct xrt_device *xdev, const char *name, void *drvdata,
+                                 const struct attribute_group **grps);
+void xleaf_unregister_hwmon(struct xrt_device *xdev, struct device *hwmon);
+int xleaf_wait_for_group_bringup(struct xrt_device *xdev);
+
+/*
+ * Character device helper APIs for use by leaf drivers
+ */
+static inline bool xleaf_devnode_enabled(struct xrt_device *xdev)
+{
+     return DEV_FILE_OPS(xdev)->xsf_ops.open;
+}
+
+int xleaf_devnode_create(struct xrt_device *xdev,
+                      const char *file_name, const char *inst_name);
+void xleaf_devnode_destroy(struct xrt_device *xdev);
+
+struct xrt_device *xleaf_devnode_open_excl(struct inode *inode);
+struct xrt_device *xleaf_devnode_open(struct inode *inode);
+void xleaf_devnode_close(struct inode *inode);
+
+/* Module's init/fini routines for leaf driver in xrt-lib module */
+#define XRT_LEAF_INIT_FINI_FUNC(name) \
+void name##_leaf_init_fini(bool init)                                        \
+{                                                                    \
+     if (init)                                                       \
+ xrt_register_driver(&xrt_##name##_driver);              \
+ else \
+ xrt_unregister_driver(&xrt_##name##_driver);            \
+}
+
+/* Module's init/fini routines for leaf driver in xrt-lib module */
+void group_leaf_init_fini(bool init);
+void vsec_leaf_init_fini(bool init);
+void devctl_leaf_init_fini(bool init);
+void axigate_leaf_init_fini(bool init);
+void icap_leaf_init_fini(bool init);
+void calib_leaf_init_fini(bool init);
+void clkfreq_leaf_init_fini(bool init);
+void clock_leaf_init_fini(bool init);
+void ucs_leaf_init_fini(bool init);
+
+#endif       /* _XRT_LEAF_H_ */
diff --git a/drivers/fpga/xrt/include/xleaf/clkfreq.h b/drivers/fpga/xrt/include/xleaf/clkfreq.h
new file mode 100644
index 000000000000..005441d5df78
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/clkfreq.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *   Lizhi Hou <Lizhi.Hou@xxxxxxxxxx>
+ */
+
+#ifndef _XRT_CLKFREQ_H_
+#define _XRT_CLKFREQ_H_
+
+#include "xleaf.h"
+
+/*
+ * CLKFREQ driver leaf calls.
+ */
+enum xrt_clkfreq_leaf_cmd {
+     XRT_CLKFREQ_READ = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+};
+
+#endif       /* _XRT_CLKFREQ_H_ */
diff --git a/drivers/fpga/xrt/include/xleaf/clock.h b/drivers/fpga/xrt/include/xleaf/clock.h
new file mode 100644
index 000000000000..1379e24fa5d0
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/clock.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *   Lizhi Hou <Lizhi.Hou@xxxxxxxxxx>
+ */
+
+#ifndef _XRT_CLOCK_H_
+#define _XRT_CLOCK_H_
+
+#include "xleaf.h"
+#include <linux/fpga_xrt.h>
+
+/*
+ * CLOCK driver leaf calls.
+ */
+enum xrt_clock_leaf_cmd {
+     XRT_CLOCK_SET = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+     XRT_CLOCK_GET,
+     XRT_CLOCK_VERIFY,
+};
+
+struct xrt_clock_get {
+     u16 freq;
+     u32 freq_cnter;
+};
+
+#endif       /* _XRT_CLOCK_H_ */
diff --git a/drivers/fpga/xrt/include/xleaf/ddr_calibration.h b/drivers/fpga/xrt/include/xleaf/ddr_calibration.h
new file mode 100644
index 000000000000..c44ae30f939a
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/ddr_calibration.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *   Cheng Zhen <maxz@xxxxxxxxxx>
+ */
+
+#ifndef _XRT_DDR_CALIBRATION_H_
+#define _XRT_DDR_CALIBRATION_H_
+
+#include "xleaf.h"
+#include <linux/fpga-xrt.h>
+
+/*
+ * Memory calibration driver leaf calls.
+ */
+enum xrt_calib_results {
+     XRT_CALIB_UNKNOWN = 0,
+     XRT_CALIB_SUCCEEDED,
+     XRT_CALIB_FAILED,
+};
+
+enum xrt_calib_leaf_cmd {
+     XRT_CALIB_RESULT = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+};
+
+#endif       /* _XRT_DDR_CALIBRATION_H_ */
diff --git a/drivers/fpga/xrt/include/xleaf/devctl.h b/drivers/fpga/xrt/include/xleaf/devctl.h
new file mode 100644
index 000000000000..b97f3b6d9326
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/devctl.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *   Lizhi Hou <Lizhi.Hou@xxxxxxxxxx>
+ */
+
+#ifndef _XRT_DEVCTL_H_
+#define _XRT_DEVCTL_H_
+
+#include "xleaf.h"
+
+/*
+ * DEVCTL driver leaf calls.
+ */
+enum xrt_devctl_leaf_cmd {
+     XRT_DEVCTL_READ = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+};
+
+enum xrt_devctl_id {
+     XRT_DEVCTL_ROM_UUID = 0,
+     XRT_DEVCTL_DDR_CALIB,
+     XRT_DEVCTL_GOLDEN_VER,
+     XRT_DEVCTL_MAX
+};
+
+struct xrt_devctl_rw {
+     u32     xdr_id;
+     void    *xdr_buf;
+     u32     xdr_len;
+     u32     xdr_offset;
+};
+
+struct xrt_devctl_intf_uuid {
+     u32     uuid_num;
+     uuid_t  *uuids;
+};
+
+#endif       /* _XRT_DEVCTL_H_ */
diff --git a/drivers/fpga/xrt/lib/lib-drv.c b/drivers/fpga/xrt/lib/lib-drv.c
new file mode 100644
index 000000000000..2c2f9fe3e07e
--- /dev/null
+++ b/drivers/fpga/xrt/lib/lib-drv.c
@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *   Cheng Zhen <maxz@xxxxxxxxxx>
+ *   Lizhi Hou <lizhi.hou@xxxxxxxxxx>
+ */
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include "xleaf.h"
+#include "xroot.h"
+#include "lib-drv.h"
+
+#define XRT_IPLIB_MODULE_NAME                "xrt-lib"
+#define XRT_IPLIB_MODULE_VERSION     "4.0.0"
No driver versions ...
I will remove the version.
+#define XRT_DRVNAME(drv) ((drv)->driver.name)
+
+#define XRT_SUBDEV_ID_SHIFT          16
+#define XRT_SUBDEV_ID_MASK           ((1 << XRT_SUBDEV_ID_SHIFT) - 1)
+
+struct xrt_find_drv_data {
+     enum xrt_subdev_id id;
+     struct xrt_driver *xdrv;
+};
+
+struct class *xrt_class;
+static DEFINE_IDA(xrt_device_ida);
+
+static inline u32 xrt_instance_to_id(enum xrt_subdev_id id, u32 instance)
+{
+     return (id << XRT_SUBDEV_ID_SHIFT) | instance;
+}
+
+static inline u32 xrt_id_to_instance(u32 id)
+{
+     return (id & XRT_SUBDEV_ID_MASK);
Don't need braces?
I will remove the braces.
+}
+
+static int xrt_bus_match(struct device *dev, struct device_driver *drv)
+{
+     struct xrt_device *xdev = to_xrt_dev(dev);
+     struct xrt_driver *xdrv = to_xrt_drv(drv);
+
+     if (xdev->subdev_id == xdrv->subdev_id)
+             return 1;
+
+     return 0;
+}
+
+static int xrt_bus_probe(struct device *dev)
+{
+     struct xrt_driver *xdrv = to_xrt_drv(dev->driver);
+     struct xrt_device *xdev = to_xrt_dev(dev);
+
+     return xdrv->probe(xdev);
+}
+
+static int xrt_bus_remove(struct device *dev)
+{
+     struct xrt_driver *xdrv = to_xrt_drv(dev->driver);
+     struct xrt_device *xdev = to_xrt_dev(dev);
+
+     if (xdrv->remove)
+             xdrv->remove(xdev);
+
+     return 0;
+}
+
+struct bus_type xrt_bus_type = {
+     .name           = "xrt",
+     .match          = xrt_bus_match,
+     .probe          = xrt_bus_probe,
+     .remove         = xrt_bus_remove,
+};
+
+int xrt_register_driver(struct xrt_driver *drv)
+{
+     const char *drvname = XRT_DRVNAME(drv);
+     int rc = 0;
+
+     /* Initialize dev_t for char dev node. */
+     if (drv->file_ops.xsf_ops.open) {
+             rc = alloc_chrdev_region(&drv->file_ops.xsf_dev_t, 0,
+                                      XRT_MAX_DEVICE_NODES, drvname);
+             if (rc) {
+                     pr_err("failed to alloc dev minor for %s: %d\n", drvname, rc);
+                     return rc;
+             }
+     } else {
+             drv->file_ops.xsf_dev_t = (dev_t)-1;
+     }
+
+     drv->driver.owner = THIS_MODULE;
+     drv->driver.bus = &xrt_bus_type;
+
+     rc = driver_register(&drv->driver);
+     if (rc) {
+             pr_err("register %s xrt driver failed\n", drvname);
+             if (drv->file_ops.xsf_dev_t != (dev_t)-1) {
+ unregister_chrdev_region(drv->file_ops.xsf_dev_t,
+ XRT_MAX_DEVICE_NODES);
+             }
+             return rc;
+     }
+
+     pr_info("%s registered successfully\n", drvname);
+
+     return 0;
+}
+EXPORT_SYMBOL_GPL(xrt_register_driver);
+
+void xrt_unregister_driver(struct xrt_driver *drv)
+{
+     driver_unregister(&drv->driver);
+
+     if (drv->file_ops.xsf_dev_t != (dev_t)-1)
+ unregister_chrdev_region(drv->file_ops.xsf_dev_t, XRT_MAX_DEVICE_NODES);
+
+     pr_info("%s unregistered successfully\n", XRT_DRVNAME(drv));
Drop this.
Sure.
+}
+EXPORT_SYMBOL_GPL(xrt_unregister_driver);
+
+static int __find_driver(struct device_driver *drv, void *_data)
+{
+     struct xrt_driver *xdrv = to_xrt_drv(drv);
+     struct xrt_find_drv_data *data = _data;
+
+     if (xdrv->subdev_id == data->id) {
+             data->xdrv = xdrv;
+             return 1;
+     }
+
+     return 0;
+}
+
+const char *xrt_drv_name(enum xrt_subdev_id id)
+{
+     struct xrt_find_drv_data data = { 0 };
+
+     data.id = id;
+     bus_for_each_drv(&xrt_bus_type, NULL, &data, __find_driver);
+
+     if (data.xdrv)
+             return XRT_DRVNAME(data.xdrv);
+
+     return NULL;
+}
+
+static int xrt_drv_get_instance(enum xrt_subdev_id id)
+{
+     int ret;
+
+     ret = ida_alloc_range(&xrt_device_ida, xrt_instance_to_id(id, 0),
+                           xrt_instance_to_id(id, XRT_MAX_DEVICE_NODES),
+                           GFP_KERNEL);
+     if (ret < 0)
+             return ret;
+
+     return xrt_id_to_instance((u32)ret);
+}
+
+static void xrt_drv_put_instance(enum xrt_subdev_id id, int instance)
+{
+     ida_free(&xrt_device_ida, xrt_instance_to_id(id, instance));
+}
+
+struct xrt_dev_endpoints *xrt_drv_get_endpoints(enum xrt_subdev_id id)
+{
+     struct xrt_find_drv_data data = { 0 };
+
+     data.id = id;
+     bus_for_each_drv(&xrt_bus_type, NULL, &data, __find_driver);
+
+     if (data.xdrv)
+             return data.xdrv->endpoints;
+
+     return NULL;
+}
+
+static void xrt_device_release(struct device *dev)
+{
+     struct xrt_device *xdev = container_of(dev, struct xrt_device, dev);
+
+     kfree(xdev);
+}
+
+void xrt_device_unregister(struct xrt_device *xdev)
+{
+     if (xdev->state == XRT_DEVICE_STATE_ADDED)
+             device_del(&xdev->dev);
+
+     vfree(xdev->sdev_data);
+     kfree(xdev->resource);
+
+     if (xdev->instance != XRT_INVALID_DEVICE_INST)
+             xrt_drv_put_instance(xdev->subdev_id, xdev->instance);
+
+     if (xdev->dev.release == xrt_device_release)
+             put_device(&xdev->dev);
+}
+
+struct xrt_device *
+xrt_device_register(struct device *parent, u32 id,
+                 struct resource *res, u32 res_num,
+                 void *pdata, size_t data_sz)
+{
+     struct xrt_device *xdev = NULL;
+     int ret;
+
+     xdev = kzalloc(sizeof(*xdev), GFP_KERNEL);
+     if (!xdev)
+             return NULL;
Nit: return xdev
Sure.
+     xdev->instance = XRT_INVALID_DEVICE_INST;
+
+     /* Obtain dev instance number. */
+     ret = xrt_drv_get_instance(id);
+     if (ret < 0) {
+             dev_err(parent, "failed get instance, ret %d", ret);
+             goto fail;
+     }
+
+     xdev->instance = ret;
+     xdev->name = xrt_drv_name(id);
+     xdev->subdev_id = id;
+     device_initialize(&xdev->dev);
+     xdev->dev.release = xrt_device_release;
+     xdev->dev.parent = parent;
+
+     xdev->dev.bus = &xrt_bus_type;
+     dev_set_name(&xdev->dev, "%s.%d", xdev->name, xdev->instance);
+
+     xdev->num_resources = res_num;
+     xdev->resource = kmemdup(res, sizeof(*res) * res_num, GFP_KERNEL);
+     if (!xdev->resource)
+             goto fail;
+
+     xdev->sdev_data = vzalloc(data_sz);
+     if (!xdev->sdev_data)
+             goto fail;
Do you need another label here? I don't see this getting cleaned up if
device_add() fails below ...?
sdev_data will be cleaned up in xrt_device_unregister().

Thanks,
Lizhi
+
+     memcpy(xdev->sdev_data, pdata, data_sz);
+
+     ret = device_add(&xdev->dev);
+     if (ret) {
+             dev_err(parent, "failed add device, ret %d", ret);
+             goto fail;
+     }
+     xdev->state = XRT_DEVICE_STATE_ADDED;
+
+     return xdev;
+
+fail:
+     xrt_device_unregister(xdev);
+     kfree(xdev);
+
+     return NULL;
+}
+
+struct resource *xrt_get_resource(struct xrt_device *xdev, u32 type, u32 num)
+{
+     u32 i;
+
+     for (i = 0; i < xdev->num_resources; i++) {
+             struct resource *r = &xdev->resource[i];
+
+             if (type == resource_type(r) && num-- == 0)
+                     return r;
+     }
+     return NULL;
+}
+
+/*
+ * Leaf driver's module init/fini callbacks. This is not a open infrastructure for dynamic
+ * plugging in drivers. All drivers should be statically added.
+ */
+static void (*leaf_init_fini_cbs[])(bool) = {
+     group_leaf_init_fini,
+     axigate_leaf_init_fini,
+     icap_leaf_init_fini,
+};
+
+static __init int xrt_lib_init(void)
+{
+     int ret;
+     int i;
+
+     ret = bus_register(&xrt_bus_type);
+     if (ret)
+             return ret;
+
+     xrt_class = class_create(THIS_MODULE, XRT_IPLIB_MODULE_NAME);
+     if (IS_ERR(xrt_class)) {
+             bus_unregister(&xrt_bus_type);
+             return PTR_ERR(xrt_class);
+     }
+
+     for (i = 0; i < ARRAY_SIZE(leaf_init_fini_cbs); i++)
+             leaf_init_fini_cbs[i](true);
+     return 0;
+}
+
+static __exit void xrt_lib_fini(void)
+{
+     int i;
+
+     for (i = 0; i < ARRAY_SIZE(leaf_init_fini_cbs); i++)
+             leaf_init_fini_cbs[i](false);
+
+     class_destroy(xrt_class);
+     bus_unregister(&xrt_bus_type);
+}
+
+module_init(xrt_lib_init);
+module_exit(xrt_lib_fini);
+
+MODULE_VERSION(XRT_IPLIB_MODULE_VERSION);
+MODULE_AUTHOR("XRT Team <runtime@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Xilinx Alveo IP Lib driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/fpga/xrt/lib/lib-drv.h b/drivers/fpga/xrt/lib/lib-drv.h
new file mode 100644
index 000000000000..0276c28e009f
--- /dev/null
+++ b/drivers/fpga/xrt/lib/lib-drv.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *   Cheng Zhen <maxz@xxxxxxxxxx>
+ */
+
+#ifndef _LIB_DRV_H_
+#define _LIB_DRV_H_
+
+#include <linux/device/class.h>
+#include <linux/device/bus.h>
+
+extern struct class *xrt_class;
+extern struct bus_type xrt_bus_type;
+
+const char *xrt_drv_name(enum xrt_subdev_id id);
+struct xrt_dev_endpoints *xrt_drv_get_endpoints(enum xrt_subdev_id id);
+
+#endif       /* _LIB_DRV_H_ */
--
2.27.0