infrastructure code providing APIs for managing leaf driver instance
groups, facilitating inter-leaf driver calls and root calls, managing leaf
driver device nodes.

Signed-off-by: Sonal Santan <sonal.san...@xilinx.com>
Signed-off-by: Max Zhen <max.z...@xilinx.com>
Signed-off-by: Lizhi Hou <liz...@xilinx.com>
---
 drivers/fpga/xrt/include/events.h    |  48 ++
 drivers/fpga/xrt/include/subdev_id.h |  43 ++
 drivers/fpga/xrt/include/xleaf.h     | 276 +++++++++
 drivers/fpga/xrt/lib/cdev.c          | 231 +++++++
 drivers/fpga/xrt/lib/subdev.c        | 871 +++++++++++++++++++++++++++
 drivers/fpga/xrt/lib/subdev_pool.h   |  53 ++
 drivers/fpga/xrt/lib/xroot.c         | 598 ++++++++++++++++++
 7 files changed, 2120 insertions(+)
 create mode 100644 drivers/fpga/xrt/include/events.h
 create mode 100644 drivers/fpga/xrt/include/subdev_id.h
 create mode 100644 drivers/fpga/xrt/include/xleaf.h
 create mode 100644 drivers/fpga/xrt/lib/cdev.c
 create mode 100644 drivers/fpga/xrt/lib/subdev.c
 create mode 100644 drivers/fpga/xrt/lib/subdev_pool.h
 create mode 100644 drivers/fpga/xrt/lib/xroot.c

diff --git a/drivers/fpga/xrt/include/events.h 
b/drivers/fpga/xrt/include/events.h
new file mode 100644
index 000000000000..2a9aae8bceb4
--- /dev/null
+++ b/drivers/fpga/xrt/include/events.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Header file for Xilinx Runtime (XRT) driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *     Cheng Zhen <m...@xilinx.com>
+ */
+
+#ifndef _XRT_EVENTS_H_
+#define _XRT_EVENTS_H_
+
+#include <linux/platform_device.h>
+#include "subdev_id.h"
+
+/*
+ * Event notification.
+ */
+enum xrt_events {
+       XRT_EVENT_TEST = 0, /* for testing */
+       /*
+        * Events related to specific subdev
+        * Callback arg: struct xrt_event_arg_subdev
+        */
+       XRT_EVENT_POST_CREATION,
+       XRT_EVENT_PRE_REMOVAL,
+       /*
+        * Events related to change of the whole board
+        * Callback arg: <none>
+        */
+       XRT_EVENT_PRE_HOT_RESET,
+       XRT_EVENT_POST_HOT_RESET,
+       XRT_EVENT_PRE_GATE_CLOSE,
+       XRT_EVENT_POST_GATE_OPEN,
+};
+
+struct xrt_event_arg_subdev {
+       enum xrt_subdev_id xevt_subdev_id;
+       int xevt_subdev_instance;
+};
+
+struct xrt_event {
+       enum xrt_events xe_evt;
+       struct xrt_event_arg_subdev xe_subdev;
+};
+
+#endif /* _XRT_EVENTS_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..6205a9f26196
--- /dev/null
+++ b/drivers/fpga/xrt/include/subdev_id.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Header file for Xilinx Runtime (XRT) driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *     Cheng Zhen <m...@xilinx.com>
+ */
+
+#ifndef _XRT_SUBDEV_ID_H_
+#define _XRT_SUBDEV_ID_H_
+
+/*
+ * Every subdev driver should have an ID for others to refer to it.
+ * There can be unlimited number of instances of a subdev driver. A
+ * <subdev_id, subdev_instance> tuple should be a unique identification of
+ * a specific instance of a subdev driver.
+ * NOTE: PLEASE do not change the order of IDs. Sub devices in the same
+ * group are initialized by this order.
+ */
+enum xrt_subdev_id {
+       XRT_SUBDEV_GRP = 0,
+       XRT_SUBDEV_VSEC = 1,
+       XRT_SUBDEV_VSEC_GOLDEN = 2,
+       XRT_SUBDEV_DEVCTL = 3,
+       XRT_SUBDEV_AXIGATE = 4,
+       XRT_SUBDEV_ICAP = 5,
+       XRT_SUBDEV_TEST = 6,
+       XRT_SUBDEV_MGMT_MAIN = 7,
+       XRT_SUBDEV_QSPI = 8,
+       XRT_SUBDEV_MAILBOX = 9,
+       XRT_SUBDEV_CMC = 10,
+       XRT_SUBDEV_CALIB = 11,
+       XRT_SUBDEV_CLKFREQ = 12,
+       XRT_SUBDEV_CLOCK = 13,
+       XRT_SUBDEV_SRSR = 14,
+       XRT_SUBDEV_UCS = 15,
+       XRT_SUBDEV_NUM = 16, /* Total number of subdevs. */
+       XRT_ROOT = -1, /* Special ID for root driver. */
+};
+
+#endif /* _XRT_SUBDEV_ID_H_ */
diff --git a/drivers/fpga/xrt/include/xleaf.h b/drivers/fpga/xrt/include/xleaf.h
new file mode 100644
index 000000000000..10215a75d474
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf.h
@@ -0,0 +1,276 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Header file for Xilinx Runtime (XRT) driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *    Cheng Zhen <m...@xilinx.com>
+ *    Sonal Santan <sonal.san...@xilinx.com>
+ */
+
+#ifndef _XRT_XLEAF_H_
+#define _XRT_XLEAF_H_
+
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/pci.h>
+#include <linux/libfdt_env.h>
+#include "libfdt.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(pdev)      (&(pdev)->dev)
+#define DEV_PDATA(pdev)                                        \
+       ((struct xrt_subdev_platdata *)dev_get_platdata(DEV(pdev)))
+#define DEV_DRVDATA(pdev)                              \
+       ((struct xrt_subdev_drvdata *)                  \
+       platform_get_device_id(pdev)->driver_data)
+#define FMT_PRT(prt_fn, pdev, fmt, args...)            \
+       ({typeof(pdev) (_pdev) = (pdev);                \
+       prt_fn(DEV(_pdev), "%s %s: " fmt,               \
+       DEV_PDATA(_pdev)->xsp_root_name, __func__, ##args); })
+#define xrt_err(pdev, fmt, args...) FMT_PRT(dev_err, pdev, fmt, ##args)
+#define xrt_warn(pdev, fmt, args...) FMT_PRT(dev_warn, pdev, fmt, ##args)
+#define xrt_info(pdev, fmt, args...) FMT_PRT(dev_info, pdev, fmt, ##args)
+#define xrt_dbg(pdev, fmt, args...) FMT_PRT(dev_dbg, pdev, fmt, ##args)
+
+/* Starting IOCTL for common IOCTLs implemented by all leaves. */
+#define XRT_XLEAF_COMMON_BASE  0
+/* Starting IOCTL for leaves' specific IOCTLs. */
+#define XRT_XLEAF_CUSTOM_BASE  64
+enum xrt_xleaf_common_ioctl_cmd {
+       XRT_XLEAF_EVENT = XRT_XLEAF_COMMON_BASE,
+};
+
+/*
+ * If populated by subdev driver, infra will handle the mechanics of
+ * char device (un)registration.
+ */
+enum xrt_subdev_file_mode {
+       /* Infra create cdev, default file name */
+       XRT_SUBDEV_FILE_DEFAULT = 0,
+       /* Infra create cdev, need to encode inst num in file name */
+       XRT_SUBDEV_FILE_MULTI_INST,
+       /* No auto creation of cdev by infra, leaf handles it by itself */
+       XRT_SUBDEV_FILE_NO_AUTO,
+};
+
+struct xrt_subdev_file_ops {
+       const struct file_operations xsf_ops;
+       dev_t xsf_dev_t;
+       const char *xsf_dev_name;
+       enum xrt_subdev_file_mode xsf_mode;
+};
+
+/*
+ * Subdev driver callbacks populated by subdev driver.
+ */
+struct xrt_subdev_drv_ops {
+       /*
+        * Per driver instance callback. The pdev points to the instance.
+        * If defined these are called by other leaf drivers.
+        * Note that root driver may call into xsd_ioctl of a group driver.
+        */
+       int (*xsd_ioctl)(struct platform_device *pdev, u32 cmd, void *arg);
+};
+
+/*
+ * Defined and populated by subdev driver, exported as driver_data in
+ * struct platform_device_id.
+ */
+struct xrt_subdev_drvdata {
+       struct xrt_subdev_file_ops xsd_file_ops;
+       struct xrt_subdev_drv_ops xsd_dev_ops;
+};
+
+/*
+ * 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 (platform_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 pdev 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.
+        */
+       char xsp_dtb[sizeof(struct fdt_header)];
+};
+
+/*
+ * this struct define the endpoints belong to the same subdevice
+ */
+struct xrt_subdev_ep_names {
+       const char *ep_name;
+       const char *regmap_name;
+};
+
+struct xrt_subdev_endpoints {
+       struct xrt_subdev_ep_names *xse_names;
+       /* minimum number of endpoints to support the subdevice */
+       u32 xse_min_ep;
+};
+
+struct subdev_match_arg {
+       enum xrt_subdev_id id;
+       int instance;
+};
+
+bool xleaf_has_endpoint(struct platform_device *pdev, const char 
*endpoint_name);
+struct platform_device *xleaf_get_leaf(struct platform_device *pdev,
+                                      xrt_subdev_match_t cb, void *arg);
+
+static inline bool subdev_match(enum xrt_subdev_id id, struct platform_device 
*pdev, void *arg)
+{
+       const struct subdev_match_arg *a = (struct subdev_match_arg *)arg;
+       bool ret = (id == a->id && (pdev->id == a->instance || 
PLATFORM_DEVID_NONE == a->instance));
+
+       return ret;
+}
+
+static inline bool xrt_subdev_match_epname(enum xrt_subdev_id id,
+                                          struct platform_device *pdev, void 
*arg)
+{
+       return xleaf_has_endpoint(pdev, arg);
+}
+
+static inline struct platform_device *
+xleaf_get_leaf_by_id(struct platform_device *pdev,
+                    enum xrt_subdev_id id, int instance)
+{
+       struct subdev_match_arg arg = { id, instance };
+
+       return xleaf_get_leaf(pdev, subdev_match, &arg);
+}
+
+static inline struct platform_device *
+xleaf_get_leaf_by_epname(struct platform_device *pdev, const char *name)
+{
+       return xleaf_get_leaf(pdev, xrt_subdev_match_epname, (void *)name);
+}
+
+static inline int xleaf_ioctl(struct platform_device *tgt, u32 cmd, void *arg)
+{
+       struct xrt_subdev_drvdata *drvdata = DEV_DRVDATA(tgt);
+
+       return (*drvdata->xsd_dev_ops.xsd_ioctl)(tgt, cmd, arg);
+}
+
+int xleaf_put_leaf(struct platform_device *pdev,
+                  struct platform_device *leaf);
+int xleaf_create_group(struct platform_device *pdev, char *dtb);
+int xleaf_destroy_group(struct platform_device *pdev, int instance);
+int xleaf_wait_for_group_bringup(struct platform_device *pdev);
+void xleaf_hot_reset(struct platform_device *pdev);
+int xleaf_broadcast_event(struct platform_device *pdev,
+                         enum xrt_events evt, bool async);
+void xleaf_get_barres(struct platform_device *pdev,
+                     struct resource **res, uint bar_idx);
+void xleaf_get_root_id(struct platform_device *pdev,
+                      unsigned short *vendor, unsigned short *device,
+                      unsigned short *subvendor, unsigned short *subdevice);
+struct device *xleaf_register_hwmon(struct platform_device *pdev,
+                                   const char *name, void *drvdata,
+                                   const struct attribute_group **grps);
+void xleaf_unregister_hwmon(struct platform_device *pdev, struct device 
*hwmon);
+
+/*
+ * Character device helper APIs for use by leaf drivers
+ */
+static inline bool xleaf_devnode_enabled(struct xrt_subdev_drvdata *drvdata)
+{
+       return drvdata && drvdata->xsd_file_ops.xsf_ops.open;
+}
+
+int xleaf_devnode_create(struct platform_device *pdev,
+                        const char *file_name, const char *inst_name);
+int xleaf_devnode_destroy(struct platform_device *pdev);
+
+struct platform_device *xleaf_devnode_open_excl(struct inode *inode);
+struct platform_device *xleaf_devnode_open(struct inode *inode);
+void xleaf_devnode_close(struct inode *inode);
+
+/* Helpers. */
+static inline void xrt_memcpy_fromio(void *buf, void __iomem *iomem, u32 size)
+{
+       int i;
+
+       WARN_ON(size & 0x3);
+       for (i = 0; i < size / 4; i++)
+               ((u32 *)buf)[i] = ioread32((char *)(iomem) + sizeof(u32) * i);
+}
+
+static inline void xrt_memcpy_toio(void __iomem *iomem, void *buf, u32 size)
+{
+       int i;
+
+       WARN_ON(size & 0x3);
+       for (i = 0; i < size / 4; i++)
+               iowrite32(((u32 *)buf)[i], ((char *)(iomem) + sizeof(u32) * i));
+}
+
+int xleaf_register_driver(enum xrt_subdev_id id, struct platform_driver *drv,
+                         struct xrt_subdev_endpoints *eps);
+void xleaf_unregister_driver(enum xrt_subdev_id id);
+
+/* 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 vsec_golden_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 qspi_leaf_init_fini(bool init);
+void mailbox_leaf_init_fini(bool init);
+void cmc_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/lib/cdev.c b/drivers/fpga/xrt/lib/cdev.c
new file mode 100644
index 000000000000..7f104ab3d527
--- /dev/null
+++ b/drivers/fpga/xrt/lib/cdev.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo FPGA device node helper functions.
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *     Cheng Zhen <m...@xilinx.com>
+ */
+
+#include "xleaf.h"
+
+extern struct class *xrt_class;
+
+#define XRT_CDEV_DIR           "xfpga"
+#define INODE2PDATA(inode)     \
+       container_of((inode)->i_cdev, struct xrt_subdev_platdata, xsp_cdev)
+#define INODE2PDEV(inode)      \
+       to_platform_device(kobj_to_dev((inode)->i_cdev->kobj.parent))
+#define CDEV_NAME(sysdev)      (strchr((sysdev)->kobj.name, '!') + 1)
+
+/* Allow it to be accessed from cdev. */
+static void xleaf_devnode_allowed(struct platform_device *pdev)
+{
+       struct xrt_subdev_platdata *pdata = DEV_PDATA(pdev);
+
+       /* Allow new opens. */
+       mutex_lock(&pdata->xsp_devnode_lock);
+       pdata->xsp_devnode_online = true;
+       mutex_unlock(&pdata->xsp_devnode_lock);
+}
+
+/* Turn off access from cdev and wait for all existing user to go away. */
+static int xleaf_devnode_disallowed(struct platform_device *pdev)
+{
+       int ret = 0;
+       struct xrt_subdev_platdata *pdata = DEV_PDATA(pdev);
+
+       mutex_lock(&pdata->xsp_devnode_lock);
+
+       /* Prevent new opens. */
+       pdata->xsp_devnode_online = false;
+       /* Wait for existing user to close. */
+       while (!ret && pdata->xsp_devnode_ref) {
+               int rc;
+
+               mutex_unlock(&pdata->xsp_devnode_lock);
+               rc = wait_for_completion_killable(&pdata->xsp_devnode_comp);
+               mutex_lock(&pdata->xsp_devnode_lock);
+
+               if (rc == -ERESTARTSYS) {
+                       /* Restore online state. */
+                       pdata->xsp_devnode_online = true;
+                       xrt_err(pdev, "%s is in use, ref=%d",
+                               CDEV_NAME(pdata->xsp_sysdev),
+                               pdata->xsp_devnode_ref);
+                       ret = -EBUSY;
+               }
+       }
+
+       mutex_unlock(&pdata->xsp_devnode_lock);
+
+       return ret;
+}
+
+static struct platform_device *
+__xleaf_devnode_open(struct inode *inode, bool excl)
+{
+       struct xrt_subdev_platdata *pdata = INODE2PDATA(inode);
+       struct platform_device *pdev = INODE2PDEV(inode);
+       bool opened = false;
+
+       mutex_lock(&pdata->xsp_devnode_lock);
+
+       if (pdata->xsp_devnode_online) {
+               if (excl && pdata->xsp_devnode_ref) {
+                       xrt_err(pdev, "%s has already been opened exclusively",
+                               CDEV_NAME(pdata->xsp_sysdev));
+               } else if (!excl && pdata->xsp_devnode_excl) {
+                       xrt_err(pdev, "%s has been opened exclusively",
+                               CDEV_NAME(pdata->xsp_sysdev));
+               } else {
+                       pdata->xsp_devnode_ref++;
+                       pdata->xsp_devnode_excl = excl;
+                       opened = true;
+                       xrt_info(pdev, "opened %s, ref=%d",
+                                CDEV_NAME(pdata->xsp_sysdev),
+                                pdata->xsp_devnode_ref);
+               }
+       } else {
+               xrt_err(pdev, "%s is offline", CDEV_NAME(pdata->xsp_sysdev));
+       }
+
+       mutex_unlock(&pdata->xsp_devnode_lock);
+
+       pdev = opened ? pdev : NULL;
+       return pdev;
+}
+
+struct platform_device *
+xleaf_devnode_open_excl(struct inode *inode)
+{
+       return __xleaf_devnode_open(inode, true);
+}
+
+struct platform_device *
+xleaf_devnode_open(struct inode *inode)
+{
+       return __xleaf_devnode_open(inode, false);
+}
+EXPORT_SYMBOL_GPL(xleaf_devnode_open);
+
+void xleaf_devnode_close(struct inode *inode)
+{
+       struct xrt_subdev_platdata *pdata = INODE2PDATA(inode);
+       struct platform_device *pdev = INODE2PDEV(inode);
+       bool notify = false;
+
+       mutex_lock(&pdata->xsp_devnode_lock);
+
+       pdata->xsp_devnode_ref--;
+       if (pdata->xsp_devnode_ref == 0) {
+               pdata->xsp_devnode_excl = false;
+               notify = true;
+       }
+       if (notify) {
+               xrt_info(pdev, "closed %s, ref=%d",
+                        CDEV_NAME(pdata->xsp_sysdev), pdata->xsp_devnode_ref);
+       } else {
+               xrt_info(pdev, "closed %s, notifying waiter",
+                        CDEV_NAME(pdata->xsp_sysdev));
+       }
+
+       mutex_unlock(&pdata->xsp_devnode_lock);
+
+       if (notify)
+               complete(&pdata->xsp_devnode_comp);
+}
+EXPORT_SYMBOL_GPL(xleaf_devnode_close);
+
+static inline enum xrt_subdev_file_mode
+devnode_mode(struct xrt_subdev_drvdata *drvdata)
+{
+       return drvdata->xsd_file_ops.xsf_mode;
+}
+
+int xleaf_devnode_create(struct platform_device *pdev, const char *file_name,
+                        const char *inst_name)
+{
+       struct xrt_subdev_drvdata *drvdata = DEV_DRVDATA(pdev);
+       struct xrt_subdev_file_ops *fops = &drvdata->xsd_file_ops;
+       struct xrt_subdev_platdata *pdata = DEV_PDATA(pdev);
+       struct cdev *cdevp;
+       struct device *sysdev;
+       int ret = 0;
+       char fname[256];
+
+       mutex_init(&pdata->xsp_devnode_lock);
+       init_completion(&pdata->xsp_devnode_comp);
+
+       cdevp = &DEV_PDATA(pdev)->xsp_cdev;
+       cdev_init(cdevp, &fops->xsf_ops);
+       cdevp->owner = fops->xsf_ops.owner;
+       cdevp->dev = MKDEV(MAJOR(fops->xsf_dev_t), pdev->id);
+
+       /*
+        * Set pdev as parent of cdev so that when pdev (and its platform
+        * data) will not be freed when cdev is not freed.
+        */
+       cdev_set_parent(cdevp, &DEV(pdev)->kobj);
+
+       ret = cdev_add(cdevp, cdevp->dev, 1);
+       if (ret) {
+               xrt_err(pdev, "failed to add cdev: %d", ret);
+               goto failed;
+       }
+       if (!file_name)
+               file_name = pdev->name;
+       if (!inst_name) {
+               if (devnode_mode(drvdata) == XRT_SUBDEV_FILE_MULTI_INST) {
+                       snprintf(fname, sizeof(fname), "%s/%s/%s.%u",
+                                XRT_CDEV_DIR, DEV_PDATA(pdev)->xsp_root_name,
+                                file_name, pdev->id);
+               } else {
+                       snprintf(fname, sizeof(fname), "%s/%s/%s",
+                                XRT_CDEV_DIR, DEV_PDATA(pdev)->xsp_root_name,
+                                file_name);
+               }
+       } else {
+               snprintf(fname, sizeof(fname), "%s/%s/%s.%s", XRT_CDEV_DIR,
+                        DEV_PDATA(pdev)->xsp_root_name, file_name, inst_name);
+       }
+       sysdev = device_create(xrt_class, NULL, cdevp->dev, NULL, "%s", fname);
+       if (IS_ERR(sysdev)) {
+               ret = PTR_ERR(sysdev);
+               xrt_err(pdev, "failed to create device node: %d", ret);
+               goto failed;
+       }
+       pdata->xsp_sysdev = sysdev;
+
+       xleaf_devnode_allowed(pdev);
+
+       xrt_info(pdev, "created (%d, %d): /dev/%s",
+                MAJOR(cdevp->dev), pdev->id, fname);
+       return 0;
+
+failed:
+       device_destroy(xrt_class, cdevp->dev);
+       cdev_del(cdevp);
+       cdevp->owner = NULL;
+       return ret;
+}
+
+int xleaf_devnode_destroy(struct platform_device *pdev)
+{
+       struct xrt_subdev_platdata *pdata = DEV_PDATA(pdev);
+       struct cdev *cdevp = &pdata->xsp_cdev;
+       dev_t dev = cdevp->dev;
+       int rc;
+
+       rc = xleaf_devnode_disallowed(pdev);
+       if (rc)
+               return rc;
+
+       xrt_info(pdev, "removed (%d, %d): /dev/%s/%s", MAJOR(dev), MINOR(dev),
+                XRT_CDEV_DIR, CDEV_NAME(pdata->xsp_sysdev));
+       device_destroy(xrt_class, cdevp->dev);
+       pdata->xsp_sysdev = NULL;
+       cdev_del(cdevp);
+       return 0;
+}
diff --git a/drivers/fpga/xrt/lib/subdev.c b/drivers/fpga/xrt/lib/subdev.c
new file mode 100644
index 000000000000..73552c549bdb
--- /dev/null
+++ b/drivers/fpga/xrt/lib/subdev.c
@@ -0,0 +1,871 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo FPGA device helper functions
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *     Cheng Zhen <m...@xilinx.com>
+ */
+
+#include <linux/platform_device.h>
+#include <linux/pci.h>
+#include <linux/vmalloc.h>
+#include "xleaf.h"
+#include "subdev_pool.h"
+#include "main.h"
+#include "metadata.h"
+
+#define DEV_IS_PCI(dev) ((dev)->bus == &pci_bus_type)
+static inline struct device *find_root(struct platform_device *pdev)
+{
+       struct device *d = DEV(pdev);
+
+       while (!DEV_IS_PCI(d))
+               d = d->parent;
+       return d;
+}
+
+/*
+ * It represents a holder of a subdev. One holder can repeatedly hold a subdev
+ * as long as there is a unhold corresponding to a hold.
+ */
+struct xrt_subdev_holder {
+       struct list_head xsh_holder_list;
+       struct device *xsh_holder;
+       int xsh_count;
+       struct kref xsh_kref;
+};
+
+/*
+ * It represents a specific instance of platform driver for a subdev, which
+ * provides services to its clients (another subdev driver or root driver).
+ */
+struct xrt_subdev {
+       struct list_head xs_dev_list;
+       struct list_head xs_holder_list;
+       enum xrt_subdev_id xs_id;               /* type of subdev */
+       struct platform_device *xs_pdev;        /* a particular subdev inst */
+       struct completion xs_holder_comp;
+};
+
+static struct xrt_subdev *xrt_subdev_alloc(void)
+{
+       struct xrt_subdev *sdev = vzalloc(sizeof(*sdev));
+
+       if (!sdev)
+               return NULL;
+
+       INIT_LIST_HEAD(&sdev->xs_dev_list);
+       INIT_LIST_HEAD(&sdev->xs_holder_list);
+       init_completion(&sdev->xs_holder_comp);
+       return sdev;
+}
+
+static void xrt_subdev_free(struct xrt_subdev *sdev)
+{
+       vfree(sdev);
+}
+
+int xrt_subdev_root_request(struct platform_device *self, u32 cmd, void *arg)
+{
+       struct device *dev = DEV(self);
+       struct xrt_subdev_platdata *pdata = DEV_PDATA(self);
+
+       return (*pdata->xsp_root_cb)(dev->parent, pdata->xsp_root_cb_arg, cmd, 
arg);
+}
+
+/*
+ * Subdev common sysfs nodes.
+ */
+static ssize_t holders_show(struct device *dev, struct device_attribute *attr, 
char *buf)
+{
+       ssize_t len;
+       struct platform_device *pdev = to_platform_device(dev);
+       struct xrt_root_ioctl_get_holders holders = { pdev, buf, 1024 };
+
+       len = xrt_subdev_root_request(pdev, XRT_ROOT_GET_LEAF_HOLDERS, 
&holders);
+       if (len >= holders.xpigh_holder_buf_len)
+               return len;
+       buf[len] = '\n';
+       return len + 1;
+}
+static DEVICE_ATTR_RO(holders);
+
+static struct attribute *xrt_subdev_attrs[] = {
+       &dev_attr_holders.attr,
+       NULL,
+};
+
+static ssize_t metadata_output(struct file *filp, struct kobject *kobj,
+                              struct bin_attribute *attr, char *buf, loff_t 
off, size_t count)
+{
+       struct device *dev = kobj_to_dev(kobj);
+       struct platform_device *pdev = to_platform_device(dev);
+       struct xrt_subdev_platdata *pdata = DEV_PDATA(pdev);
+       unsigned char *blob;
+       unsigned long  size;
+       ssize_t ret = 0;
+
+       blob = pdata->xsp_dtb;
+       size = xrt_md_size(dev, blob);
+       if (size == XRT_MD_INVALID_LENGTH) {
+               ret = -EINVAL;
+               goto failed;
+       }
+
+       if (off >= size)
+               goto failed;
+
+       if (off + count > size)
+               count = size - off;
+       memcpy(buf, blob + off, count);
+
+       ret = count;
+failed:
+       return ret;
+}
+
+static struct bin_attribute meta_data_attr = {
+       .attr = {
+               .name = "metadata",
+               .mode = 0400
+       },
+       .read = metadata_output,
+       .size = 0
+};
+
+static struct bin_attribute  *xrt_subdev_bin_attrs[] = {
+       &meta_data_attr,
+       NULL,
+};
+
+static const struct attribute_group xrt_subdev_attrgroup = {
+       .attrs = xrt_subdev_attrs,
+       .bin_attrs = xrt_subdev_bin_attrs,
+};
+
+/*
+ * Given the device metadata, parse it to get IO ranges and construct
+ * resource array.
+ */
+static int
+xrt_subdev_getres(struct device *parent, enum xrt_subdev_id id,
+                 char *dtb, struct resource **res, int *res_num)
+{
+       struct xrt_subdev_platdata *pdata;
+       struct resource *pci_res = NULL;
+       const u64 *bar_range;
+       const u32 *bar_idx;
+       char *ep_name = NULL, *regmap = NULL;
+       uint bar;
+       int count1 = 0, count2 = 0, ret;
+
+       if (!dtb)
+               return -EINVAL;
+
+       pdata = DEV_PDATA(to_platform_device(parent));
+
+       /* go through metadata and count endpoints in it */
+       for (xrt_md_get_next_endpoint(parent, dtb, NULL, NULL, &ep_name, 
&regmap); ep_name;
+            xrt_md_get_next_endpoint(parent, dtb, ep_name, regmap, &ep_name, 
&regmap)) {
+               ret = xrt_md_get_prop(parent, dtb, ep_name, regmap,
+                                     XRT_MD_PROP_IO_OFFSET, (const void 
**)&bar_range, NULL);
+               if (!ret)
+                       count1++;
+       }
+       if (!count1)
+               return 0;
+
+       /* allocate resource array for all endpoints been found in metadata */
+       *res = vzalloc(sizeof(**res) * count1);
+
+       /* go through all endpoints again and get IO range for each endpoint */
+       for (xrt_md_get_next_endpoint(parent, dtb, NULL, NULL, &ep_name, 
&regmap); ep_name;
+            xrt_md_get_next_endpoint(parent, dtb, ep_name, regmap, &ep_name, 
&regmap)) {
+               ret = xrt_md_get_prop(parent, dtb, ep_name, regmap,
+                                     XRT_MD_PROP_IO_OFFSET, (const void 
**)&bar_range, NULL);
+               if (ret)
+                       continue;
+               xrt_md_get_prop(parent, dtb, ep_name, regmap,
+                               XRT_MD_PROP_BAR_IDX, (const void **)&bar_idx, 
NULL);
+               bar = bar_idx ? be32_to_cpu(*bar_idx) : 0;
+               xleaf_get_barres(to_platform_device(parent), &pci_res, bar);
+               (*res)[count2].start = pci_res->start +
+                       be64_to_cpu(bar_range[0]);
+               (*res)[count2].end = pci_res->start +
+                       be64_to_cpu(bar_range[0]) +
+                       be64_to_cpu(bar_range[1]) - 1;
+               (*res)[count2].flags = IORESOURCE_MEM;
+               /* check if there is conflicted resource */
+               ret = request_resource(pci_res, *res + count2);
+               if (ret) {
+                       dev_err(parent, "Conflict resource %pR\n", *res + 
count2);
+                       vfree(*res);
+                       *res_num = 0;
+                       *res = NULL;
+                       return ret;
+               }
+               release_resource(*res + count2);
+
+               (*res)[count2].parent = pci_res;
+
+               xrt_md_find_endpoint(parent, pdata->xsp_dtb, ep_name,
+                                    regmap, &(*res)[count2].name);
+
+               count2++;
+       }
+
+       WARN_ON(count1 != count2);
+       *res_num = count2;
+
+       return 0;
+}
+
+static inline enum xrt_subdev_file_mode
+xleaf_devnode_mode(struct xrt_subdev_drvdata *drvdata)
+{
+       return drvdata->xsd_file_ops.xsf_mode;
+}
+
+static bool xrt_subdev_cdev_auto_creation(struct platform_device *pdev)
+{
+       struct xrt_subdev_drvdata *drvdata = DEV_DRVDATA(pdev);
+
+       if (!drvdata)
+               return false;
+
+       return xleaf_devnode_enabled(drvdata) &&
+               (xleaf_devnode_mode(drvdata) == XRT_SUBDEV_FILE_DEFAULT ||
+               (xleaf_devnode_mode(drvdata) == XRT_SUBDEV_FILE_MULTI_INST));
+}
+
+static struct xrt_subdev *
+xrt_subdev_create(struct device *parent, enum xrt_subdev_id id,
+                 xrt_subdev_root_cb_t pcb, void *pcb_arg, char *dtb)
+{
+       struct xrt_subdev *sdev = NULL;
+       struct platform_device *pdev = NULL;
+       struct xrt_subdev_platdata *pdata = NULL;
+       unsigned long dtb_len = 0;
+       size_t pdata_sz;
+       int inst = PLATFORM_DEVID_NONE;
+       struct resource *res = NULL;
+       int res_num = 0;
+
+       sdev = xrt_subdev_alloc();
+       if (!sdev) {
+               dev_err(parent, "failed to alloc subdev for ID %d", id);
+               goto fail;
+       }
+       sdev->xs_id = id;
+
+       if (dtb) {
+               xrt_md_pack(parent, dtb);
+               dtb_len = xrt_md_size(parent, dtb);
+               if (dtb_len == XRT_MD_INVALID_LENGTH) {
+                       dev_err(parent, "invalid metadata len %ld", dtb_len);
+                       goto fail;
+               }
+       }
+       pdata_sz = sizeof(struct xrt_subdev_platdata) + dtb_len - 1;
+
+       /* Prepare platform data passed to subdev. */
+       pdata = vzalloc(pdata_sz);
+       if (!pdata)
+               goto fail;
+
+       pdata->xsp_root_cb = pcb;
+       pdata->xsp_root_cb_arg = pcb_arg;
+       memcpy(pdata->xsp_dtb, dtb, dtb_len);
+       if (id == XRT_SUBDEV_GRP) {
+               /* Group can only be created by root driver. */
+               pdata->xsp_root_name = dev_name(parent);
+       } else {
+               struct platform_device *grp = to_platform_device(parent);
+               /* Leaf can only be created by group driver. */
+               WARN_ON(strcmp(xrt_drv_name(XRT_SUBDEV_GRP), 
platform_get_device_id(grp)->name));
+               pdata->xsp_root_name = DEV_PDATA(grp)->xsp_root_name;
+       }
+
+       /* Obtain dev instance number. */
+       inst = xrt_drv_get_instance(id);
+       if (inst < 0) {
+               dev_err(parent, "failed to obtain instance: %d", inst);
+               goto fail;
+       }
+
+       /* Create subdev. */
+       if (id == XRT_SUBDEV_GRP) {
+               pdev = platform_device_register_data(parent, 
xrt_drv_name(XRT_SUBDEV_GRP),
+                                                    inst, pdata, pdata_sz);
+       } else {
+               int rc = xrt_subdev_getres(parent, id, dtb, &res, &res_num);
+
+               if (rc) {
+                       dev_err(parent, "failed to get resource for %s.%d: %d",
+                               xrt_drv_name(id), inst, rc);
+                       goto fail;
+               }
+               pdev = platform_device_register_resndata(parent, 
xrt_drv_name(id),
+                                                        inst, res, res_num, 
pdata, pdata_sz);
+               vfree(res);
+       }
+       if (IS_ERR(pdev)) {
+               dev_err(parent, "failed to create subdev for %s inst %d: %ld",
+                       xrt_drv_name(id), inst, PTR_ERR(pdev));
+               goto fail;
+       }
+       sdev->xs_pdev = pdev;
+
+       if (device_attach(DEV(pdev)) != 1) {
+               xrt_err(pdev, "failed to attach");
+               goto fail;
+       }
+
+       if (sysfs_create_group(&DEV(pdev)->kobj, &xrt_subdev_attrgroup))
+               xrt_err(pdev, "failed to create sysfs group");
+
+       /*
+        * Create sysfs sym link under root for leaves
+        * under random groups for easy access to them.
+        */
+       if (id != XRT_SUBDEV_GRP) {
+               if (sysfs_create_link(&find_root(pdev)->kobj,
+                                     &DEV(pdev)->kobj, dev_name(DEV(pdev)))) {
+                       xrt_err(pdev, "failed to create sysfs link");
+               }
+       }
+
+       /* All done, ready to handle req thru cdev. */
+       if (xrt_subdev_cdev_auto_creation(pdev))
+               xleaf_devnode_create(pdev, 
DEV_DRVDATA(pdev)->xsd_file_ops.xsf_dev_name, NULL);
+
+       vfree(pdata);
+       return sdev;
+
+fail:
+       vfree(pdata);
+       if (sdev && !IS_ERR_OR_NULL(sdev->xs_pdev))
+               platform_device_unregister(sdev->xs_pdev);
+       if (inst >= 0)
+               xrt_drv_put_instance(id, inst);
+       xrt_subdev_free(sdev);
+       return NULL;
+}
+
+static void xrt_subdev_destroy(struct xrt_subdev *sdev)
+{
+       struct platform_device *pdev = sdev->xs_pdev;
+       int inst = pdev->id;
+       struct device *dev = DEV(pdev);
+
+       /* Take down the device node */
+       if (xrt_subdev_cdev_auto_creation(pdev))
+               xleaf_devnode_destroy(pdev);
+       if (sdev->xs_id != XRT_SUBDEV_GRP)
+               sysfs_remove_link(&find_root(pdev)->kobj, dev_name(dev));
+       sysfs_remove_group(&dev->kobj, &xrt_subdev_attrgroup);
+       platform_device_unregister(pdev);
+       xrt_drv_put_instance(sdev->xs_id, inst);
+       xrt_subdev_free(sdev);
+}
+
+struct platform_device *
+xleaf_get_leaf(struct platform_device *pdev, xrt_subdev_match_t match_cb, void 
*match_arg)
+{
+       int rc;
+       struct xrt_root_ioctl_get_leaf get_leaf = {
+               pdev, match_cb, match_arg, };
+
+       rc = xrt_subdev_root_request(pdev, XRT_ROOT_GET_LEAF, &get_leaf);
+       if (rc)
+               return NULL;
+       return get_leaf.xpigl_leaf;
+}
+EXPORT_SYMBOL_GPL(xleaf_get_leaf);
+
+bool xleaf_has_endpoint(struct platform_device *pdev, const char 
*endpoint_name)
+{
+       struct resource *res;
+       int             i;
+
+       for (i = 0, res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+           res;
+           res = platform_get_resource(pdev, IORESOURCE_MEM, ++i)) {
+               if (!strncmp(res->name, endpoint_name, strlen(res->name) + 1))
+                       return true;
+       }
+
+       return false;
+}
+EXPORT_SYMBOL_GPL(xleaf_has_endpoint);
+
+int xleaf_put_leaf(struct platform_device *pdev, struct platform_device *leaf)
+{
+       struct xrt_root_ioctl_put_leaf put_leaf = { pdev, leaf };
+
+       return xrt_subdev_root_request(pdev, XRT_ROOT_PUT_LEAF, &put_leaf);
+}
+EXPORT_SYMBOL_GPL(xleaf_put_leaf);
+
+int xleaf_create_group(struct platform_device *pdev, char *dtb)
+{
+       return xrt_subdev_root_request(pdev, XRT_ROOT_CREATE_GROUP, dtb);
+}
+EXPORT_SYMBOL_GPL(xleaf_create_group);
+
+int xleaf_destroy_group(struct platform_device *pdev, int instance)
+{
+       return xrt_subdev_root_request(pdev, XRT_ROOT_REMOVE_GROUP, (void 
*)(uintptr_t)instance);
+}
+EXPORT_SYMBOL_GPL(xleaf_destroy_group);
+
+int xleaf_wait_for_group_bringup(struct platform_device *pdev)
+{
+       return xrt_subdev_root_request(pdev, XRT_ROOT_WAIT_GROUP_BRINGUP, NULL);
+}
+EXPORT_SYMBOL_GPL(xleaf_wait_for_group_bringup);
+
+static ssize_t
+xrt_subdev_get_holders(struct xrt_subdev *sdev, char *buf, size_t len)
+{
+       const struct list_head *ptr;
+       struct xrt_subdev_holder *h;
+       ssize_t n = 0;
+
+       list_for_each(ptr, &sdev->xs_holder_list) {
+               h = list_entry(ptr, struct xrt_subdev_holder, xsh_holder_list);
+               n += snprintf(buf + n, len - n, "%s:%d ",
+                             dev_name(h->xsh_holder), kref_read(&h->xsh_kref));
+               if (n >= (len - 1))
+                       break;
+       }
+       return n;
+}
+
+void xrt_subdev_pool_init(struct device *dev, struct xrt_subdev_pool *spool)
+{
+       INIT_LIST_HEAD(&spool->xsp_dev_list);
+       spool->xsp_owner = dev;
+       mutex_init(&spool->xsp_lock);
+       spool->xsp_closing = false;
+}
+
+static void xrt_subdev_free_holder(struct xrt_subdev_holder *holder)
+{
+       list_del(&holder->xsh_holder_list);
+       vfree(holder);
+}
+
+static void xrt_subdev_pool_wait_for_holders(struct xrt_subdev_pool *spool, 
struct xrt_subdev *sdev)
+{
+       const struct list_head *ptr, *next;
+       char holders[128];
+       struct xrt_subdev_holder *holder;
+       struct mutex *lk = &spool->xsp_lock;
+
+       WARN_ON(!mutex_is_locked(lk));
+
+       while (!list_empty(&sdev->xs_holder_list)) {
+               int rc;
+
+               /* It's most likely a bug if we ever enters this loop. */
+               xrt_subdev_get_holders(sdev, holders, sizeof(holders));
+               xrt_err(sdev->xs_pdev, "awaits holders: %s", holders);
+               mutex_unlock(lk);
+               rc = wait_for_completion_killable(&sdev->xs_holder_comp);
+               mutex_lock(lk);
+               if (rc == -ERESTARTSYS) {
+                       xrt_err(sdev->xs_pdev, "give up on waiting for holders, 
clean up now");
+                       list_for_each_safe(ptr, next, &sdev->xs_holder_list) {
+                               holder = list_entry(ptr, struct 
xrt_subdev_holder, xsh_holder_list);
+                               xrt_subdev_free_holder(holder);
+                       }
+               }
+       }
+}
+
+void xrt_subdev_pool_fini(struct xrt_subdev_pool *spool)
+{
+       struct list_head *dl = &spool->xsp_dev_list;
+       struct mutex *lk = &spool->xsp_lock;
+
+       mutex_lock(lk);
+
+       if (spool->xsp_closing) {
+               mutex_unlock(lk);
+               return;
+       }
+
+       spool->xsp_closing = true;
+       /* Remove subdev in the reverse order of added. */
+       while (!list_empty(dl)) {
+               struct xrt_subdev *sdev = list_first_entry(dl, struct 
xrt_subdev, xs_dev_list);
+
+               xrt_subdev_pool_wait_for_holders(spool, sdev);
+               list_del(&sdev->xs_dev_list);
+               mutex_unlock(lk);
+               xrt_subdev_destroy(sdev);
+               mutex_lock(lk);
+       }
+
+       mutex_unlock(lk);
+}
+
+static struct xrt_subdev_holder *xrt_subdev_find_holder(struct xrt_subdev 
*sdev,
+                                                       struct device 
*holder_dev)
+{
+       struct list_head *hl = &sdev->xs_holder_list;
+       struct xrt_subdev_holder *holder;
+       const struct list_head *ptr;
+
+       list_for_each(ptr, hl) {
+               holder = list_entry(ptr, struct xrt_subdev_holder, 
xsh_holder_list);
+               if (holder->xsh_holder == holder_dev)
+                       return holder;
+       }
+       return NULL;
+}
+
+static int xrt_subdev_hold(struct xrt_subdev *sdev, struct device *holder_dev)
+{
+       struct xrt_subdev_holder *holder = xrt_subdev_find_holder(sdev, 
holder_dev);
+       struct list_head *hl = &sdev->xs_holder_list;
+
+       if (!holder) {
+               holder = vzalloc(sizeof(*holder));
+               if (!holder)
+                       return -ENOMEM;
+               holder->xsh_holder = holder_dev;
+               kref_init(&holder->xsh_kref);
+               list_add_tail(&holder->xsh_holder_list, hl);
+       } else {
+               kref_get(&holder->xsh_kref);
+       }
+
+       return 0;
+}
+
+static void xrt_subdev_free_holder_kref(struct kref *kref)
+{
+       struct xrt_subdev_holder *holder = container_of(kref, struct 
xrt_subdev_holder, xsh_kref);
+
+       xrt_subdev_free_holder(holder);
+}
+
+static int
+xrt_subdev_release(struct xrt_subdev *sdev, struct device *holder_dev)
+{
+       struct xrt_subdev_holder *holder = xrt_subdev_find_holder(sdev, 
holder_dev);
+       struct list_head *hl = &sdev->xs_holder_list;
+
+       if (!holder) {
+               dev_err(holder_dev, "can't release, %s did not hold %s",
+                       dev_name(holder_dev), dev_name(DEV(sdev->xs_pdev)));
+               return -EINVAL;
+       }
+       kref_put(&holder->xsh_kref, xrt_subdev_free_holder_kref);
+
+       /* kref_put above may remove holder from list. */
+       if (list_empty(hl))
+               complete(&sdev->xs_holder_comp);
+       return 0;
+}
+
+int xrt_subdev_pool_add(struct xrt_subdev_pool *spool, enum xrt_subdev_id id,
+                       xrt_subdev_root_cb_t pcb, void *pcb_arg, char *dtb)
+{
+       struct mutex *lk = &spool->xsp_lock;
+       struct list_head *dl = &spool->xsp_dev_list;
+       struct xrt_subdev *sdev;
+       int ret = 0;
+
+       sdev = xrt_subdev_create(spool->xsp_owner, id, pcb, pcb_arg, dtb);
+       if (sdev) {
+               mutex_lock(lk);
+               if (spool->xsp_closing) {
+                       /* No new subdev when pool is going away. */
+                       xrt_err(sdev->xs_pdev, "pool is closing");
+                       ret = -ENODEV;
+               } else {
+                       list_add(&sdev->xs_dev_list, dl);
+               }
+               mutex_unlock(lk);
+               if (ret)
+                       xrt_subdev_destroy(sdev);
+       } else {
+               ret = -EINVAL;
+       }
+
+       ret = ret ? ret : sdev->xs_pdev->id;
+       return ret;
+}
+
+int xrt_subdev_pool_del(struct xrt_subdev_pool *spool, enum xrt_subdev_id id, 
int instance)
+{
+       const struct list_head *ptr;
+       struct mutex *lk = &spool->xsp_lock;
+       struct list_head *dl = &spool->xsp_dev_list;
+       struct xrt_subdev *sdev;
+       int ret = -ENOENT;
+
+       mutex_lock(lk);
+       list_for_each(ptr, dl) {
+               sdev = list_entry(ptr, struct xrt_subdev, xs_dev_list);
+               if (sdev->xs_id != id || sdev->xs_pdev->id != instance)
+                       continue;
+               xrt_subdev_pool_wait_for_holders(spool, sdev);
+               list_del(&sdev->xs_dev_list);
+               ret = 0;
+               break;
+       }
+       mutex_unlock(lk);
+       if (ret)
+               return ret;
+
+       xrt_subdev_destroy(sdev);
+       return 0;
+}
+
+static int xrt_subdev_pool_get_impl(struct xrt_subdev_pool *spool, 
xrt_subdev_match_t match,
+                                   void *arg, struct device *holder_dev, 
struct xrt_subdev **sdevp)
+{
+       const struct list_head *ptr;
+       struct mutex *lk = &spool->xsp_lock;
+       struct list_head *dl = &spool->xsp_dev_list;
+       struct xrt_subdev *sdev = NULL;
+       int ret = -ENOENT;
+
+       mutex_lock(lk);
+
+       if (match == XRT_SUBDEV_MATCH_PREV) {
+               struct platform_device *pdev = (struct platform_device *)arg;
+               struct xrt_subdev *d = NULL;
+
+               if (!pdev) {
+                       sdev = list_empty(dl) ? NULL :
+                               list_last_entry(dl, struct xrt_subdev, 
xs_dev_list);
+               } else {
+                       list_for_each(ptr, dl) {
+                               d = list_entry(ptr, struct xrt_subdev, 
xs_dev_list);
+                               if (d->xs_pdev != pdev)
+                                       continue;
+                               if (!list_is_first(ptr, dl))
+                                       sdev = list_prev_entry(d, xs_dev_list);
+                               break;
+                       }
+               }
+       } else if (match == XRT_SUBDEV_MATCH_NEXT) {
+               struct platform_device *pdev = (struct platform_device *)arg;
+               struct xrt_subdev *d = NULL;
+
+               if (!pdev) {
+                       sdev = list_first_entry_or_null(dl, struct xrt_subdev, 
xs_dev_list);
+               } else {
+                       list_for_each(ptr, dl) {
+                               d = list_entry(ptr, struct xrt_subdev, 
xs_dev_list);
+                               if (d->xs_pdev != pdev)
+                                       continue;
+                               if (!list_is_last(ptr, dl))
+                                       sdev = list_next_entry(d, xs_dev_list);
+                               break;
+                       }
+               }
+       } else {
+               list_for_each(ptr, dl) {
+                       struct xrt_subdev *d = NULL;
+
+                       d = list_entry(ptr, struct xrt_subdev, xs_dev_list);
+                       if (d && !match(d->xs_id, d->xs_pdev, arg))
+                               continue;
+                       sdev = d;
+                       break;
+               }
+       }
+
+       if (sdev)
+               ret = xrt_subdev_hold(sdev, holder_dev);
+
+       mutex_unlock(lk);
+
+       if (!ret)
+               *sdevp = sdev;
+       return ret;
+}
+
+int xrt_subdev_pool_get(struct xrt_subdev_pool *spool, xrt_subdev_match_t 
match, void *arg,
+                       struct device *holder_dev, struct platform_device 
**pdevp)
+{
+       int rc;
+       struct xrt_subdev *sdev;
+
+       rc = xrt_subdev_pool_get_impl(spool, match, arg, holder_dev, &sdev);
+       if (rc) {
+               if (rc != -ENOENT)
+                       dev_err(holder_dev, "failed to hold device: %d", rc);
+               return rc;
+       }
+
+       if (!DEV_IS_PCI(holder_dev)) {
+               xrt_dbg(to_platform_device(holder_dev), "%s <<==== %s",
+                       dev_name(holder_dev), dev_name(DEV(sdev->xs_pdev)));
+       }
+
+       *pdevp = sdev->xs_pdev;
+       return 0;
+}
+
+static int xrt_subdev_pool_put_impl(struct xrt_subdev_pool *spool, struct 
platform_device *pdev,
+                                   struct device *holder_dev)
+{
+       const struct list_head *ptr;
+       struct mutex *lk = &spool->xsp_lock;
+       struct list_head *dl = &spool->xsp_dev_list;
+       struct xrt_subdev *sdev;
+       int ret = -ENOENT;
+
+       mutex_lock(lk);
+       list_for_each(ptr, dl) {
+               sdev = list_entry(ptr, struct xrt_subdev, xs_dev_list);
+               if (sdev->xs_pdev != pdev)
+                       continue;
+               ret = xrt_subdev_release(sdev, holder_dev);
+               break;
+       }
+       mutex_unlock(lk);
+
+       return ret;
+}
+
+int xrt_subdev_pool_put(struct xrt_subdev_pool *spool, struct platform_device 
*pdev,
+                       struct device *holder_dev)
+{
+       int ret = xrt_subdev_pool_put_impl(spool, pdev, holder_dev);
+
+       if (ret)
+               return ret;
+
+       if (!DEV_IS_PCI(holder_dev)) {
+               xrt_dbg(to_platform_device(holder_dev), "%s <<==X== %s",
+                       dev_name(holder_dev), dev_name(DEV(pdev)));
+       }
+       return 0;
+}
+
+void xrt_subdev_pool_trigger_event(struct xrt_subdev_pool *spool, enum 
xrt_events e)
+{
+       struct platform_device *tgt = NULL;
+       struct xrt_subdev *sdev = NULL;
+       struct xrt_event evt;
+
+       while (!xrt_subdev_pool_get_impl(spool, XRT_SUBDEV_MATCH_NEXT,
+                                        tgt, spool->xsp_owner, &sdev)) {
+               tgt = sdev->xs_pdev;
+               evt.xe_evt = e;
+               evt.xe_subdev.xevt_subdev_id = sdev->xs_id;
+               evt.xe_subdev.xevt_subdev_instance = tgt->id;
+               xrt_subdev_root_request(tgt, XRT_ROOT_EVENT, &evt);
+               xrt_subdev_pool_put_impl(spool, tgt, spool->xsp_owner);
+       }
+}
+
+void xrt_subdev_pool_handle_event(struct xrt_subdev_pool *spool, struct 
xrt_event *evt)
+{
+       struct platform_device *tgt = NULL;
+       struct xrt_subdev *sdev = NULL;
+
+       while (!xrt_subdev_pool_get_impl(spool, XRT_SUBDEV_MATCH_NEXT,
+                                        tgt, spool->xsp_owner, &sdev)) {
+               tgt = sdev->xs_pdev;
+               xleaf_ioctl(tgt, XRT_XLEAF_EVENT, evt);
+               xrt_subdev_pool_put_impl(spool, tgt, spool->xsp_owner);
+       }
+}
+
+ssize_t xrt_subdev_pool_get_holders(struct xrt_subdev_pool *spool,
+                                   struct platform_device *pdev, char *buf, 
size_t len)
+{
+       const struct list_head *ptr;
+       struct mutex *lk = &spool->xsp_lock;
+       struct list_head *dl = &spool->xsp_dev_list;
+       struct xrt_subdev *sdev;
+       ssize_t ret = 0;
+
+       mutex_lock(lk);
+       list_for_each(ptr, dl) {
+               sdev = list_entry(ptr, struct xrt_subdev, xs_dev_list);
+               if (sdev->xs_pdev != pdev)
+                       continue;
+               ret = xrt_subdev_get_holders(sdev, buf, len);
+               break;
+       }
+       mutex_unlock(lk);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(xrt_subdev_pool_get_holders);
+
+int xleaf_broadcast_event(struct platform_device *pdev, enum xrt_events evt, 
bool async)
+{
+       struct xrt_event e = { evt, };
+       u32 cmd = async ? XRT_ROOT_EVENT_ASYNC : XRT_ROOT_EVENT;
+
+       WARN_ON(evt == XRT_EVENT_POST_CREATION || evt == XRT_EVENT_PRE_REMOVAL);
+       return xrt_subdev_root_request(pdev, cmd, &e);
+}
+EXPORT_SYMBOL_GPL(xleaf_broadcast_event);
+
+void xleaf_hot_reset(struct platform_device *pdev)
+{
+       xrt_subdev_root_request(pdev, XRT_ROOT_HOT_RESET, NULL);
+}
+EXPORT_SYMBOL_GPL(xleaf_hot_reset);
+
+void xleaf_get_barres(struct platform_device *pdev, struct resource **res, 
uint bar_idx)
+{
+       struct xrt_root_ioctl_get_res arg = { 0 };
+
+       if (bar_idx > PCI_STD_RESOURCE_END) {
+               xrt_err(pdev, "Invalid bar idx %d", bar_idx);
+               *res = NULL;
+               return;
+       }
+
+       xrt_subdev_root_request(pdev, XRT_ROOT_GET_RESOURCE, &arg);
+
+       *res = &arg.xpigr_res[bar_idx];
+}
+
+void xleaf_get_root_id(struct platform_device *pdev, unsigned short *vendor, 
unsigned short *device,
+                      unsigned short *subvendor, unsigned short *subdevice)
+{
+       struct xrt_root_ioctl_get_id id = { 0 };
+
+       xrt_subdev_root_request(pdev, XRT_ROOT_GET_ID, (void *)&id);
+       if (vendor)
+               *vendor = id.xpigi_vendor_id;
+       if (device)
+               *device = id.xpigi_device_id;
+       if (subvendor)
+               *subvendor = id.xpigi_sub_vendor_id;
+       if (subdevice)
+               *subdevice = id.xpigi_sub_device_id;
+}
+
+struct device *xleaf_register_hwmon(struct platform_device *pdev, const char 
*name, void *drvdata,
+                                   const struct attribute_group **grps)
+{
+       struct xrt_root_ioctl_hwmon hm = { true, name, drvdata, grps, };
+
+       xrt_subdev_root_request(pdev, XRT_ROOT_HWMON, (void *)&hm);
+       return hm.xpih_hwmon_dev;
+}
+
+void xleaf_unregister_hwmon(struct platform_device *pdev, struct device *hwmon)
+{
+       struct xrt_root_ioctl_hwmon hm = { false, };
+
+       hm.xpih_hwmon_dev = hwmon;
+       xrt_subdev_root_request(pdev, XRT_ROOT_HWMON, (void *)&hm);
+}
diff --git a/drivers/fpga/xrt/lib/subdev_pool.h 
b/drivers/fpga/xrt/lib/subdev_pool.h
new file mode 100644
index 000000000000..50a8490e0e41
--- /dev/null
+++ b/drivers/fpga/xrt/lib/subdev_pool.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Header file for Xilinx Runtime (XRT) driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *     Cheng Zhen <m...@xilinx.com>
+ */
+
+#ifndef _XRT_SUBDEV_POOL_H_
+#define _XRT_SUBDEV_POOL_H_
+
+#include "xroot.h"
+
+/*
+ * It manages a list of xrt_subdevs for root and group drivers.
+ */
+struct xrt_subdev_pool {
+       struct list_head xsp_dev_list;
+       struct device *xsp_owner;
+       struct mutex xsp_lock; /* pool lock */
+       bool xsp_closing;
+};
+
+/*
+ * Subdev pool API for root and group drivers only.
+ */
+void xrt_subdev_pool_init(struct device *dev,
+                         struct xrt_subdev_pool *spool);
+void xrt_subdev_pool_fini(struct xrt_subdev_pool *spool);
+int xrt_subdev_pool_get(struct xrt_subdev_pool *spool,
+                       xrt_subdev_match_t match,
+                       void *arg, struct device *holder_dev,
+                       struct platform_device **pdevp);
+int xrt_subdev_pool_put(struct xrt_subdev_pool *spool,
+                       struct platform_device *pdev,
+                       struct device *holder_dev);
+int xrt_subdev_pool_add(struct xrt_subdev_pool *spool,
+                       enum xrt_subdev_id id, xrt_subdev_root_cb_t pcb,
+                       void *pcb_arg, char *dtb);
+int xrt_subdev_pool_del(struct xrt_subdev_pool *spool,
+                       enum xrt_subdev_id id, int instance);
+ssize_t xrt_subdev_pool_get_holders(struct xrt_subdev_pool *spool,
+                                   struct platform_device *pdev,
+                                   char *buf, size_t len);
+
+void xrt_subdev_pool_trigger_event(struct xrt_subdev_pool *spool,
+                                  enum xrt_events evt);
+void xrt_subdev_pool_handle_event(struct xrt_subdev_pool *spool,
+                                 struct xrt_event *evt);
+
+#endif /* _XRT_SUBDEV_POOL_H_ */
diff --git a/drivers/fpga/xrt/lib/xroot.c b/drivers/fpga/xrt/lib/xroot.c
new file mode 100644
index 000000000000..3dc7b0243277
--- /dev/null
+++ b/drivers/fpga/xrt/lib/xroot.c
@@ -0,0 +1,598 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo FPGA Root Functions
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *     Cheng Zhen <m...@xilinx.com>
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/hwmon.h>
+#include "xroot.h"
+#include "subdev_pool.h"
+#include "group.h"
+#include "metadata.h"
+
+#define XROOT_PDEV(xr)         ((xr)->pdev)
+#define XROOT_DEV(xr)          (&(XROOT_PDEV(xr)->dev))
+#define xroot_err(xr, fmt, args...)    \
+       dev_err(XROOT_DEV(xr), "%s: " fmt, __func__, ##args)
+#define xroot_warn(xr, fmt, args...)   \
+       dev_warn(XROOT_DEV(xr), "%s: " fmt, __func__, ##args)
+#define xroot_info(xr, fmt, args...)   \
+       dev_info(XROOT_DEV(xr), "%s: " fmt, __func__, ##args)
+#define xroot_dbg(xr, fmt, args...)    \
+       dev_dbg(XROOT_DEV(xr), "%s: " fmt, __func__, ##args)
+
+#define XRT_VSEC_ID            0x20
+
+#define XROOT_GRP_FIRST                (-1)
+#define XROOT_GRP_LAST         (-2)
+
+static int xroot_root_cb(struct device *, void *, u32, void *);
+
+struct xroot_evt {
+       struct list_head list;
+       struct xrt_event evt;
+       struct completion comp;
+       bool async;
+};
+
+struct xroot_events {
+       struct mutex evt_lock; /* event lock */
+       struct list_head evt_list;
+       struct work_struct evt_work;
+};
+
+struct xroot_grps {
+       struct xrt_subdev_pool pool;
+       struct work_struct bringup_work;
+       atomic_t bringup_pending;
+       atomic_t bringup_failed;
+       struct completion bringup_comp;
+};
+
+struct xroot {
+       struct pci_dev *pdev;
+       struct xroot_events events;
+       struct xroot_grps grps;
+       struct xroot_pf_cb pf_cb;
+};
+
+struct xroot_grp_match_arg {
+       enum xrt_subdev_id id;
+       int instance;
+};
+
+static bool xroot_grp_match(enum xrt_subdev_id id,
+                           struct platform_device *pdev, void *arg)
+{
+       struct xroot_grp_match_arg *a = (struct xroot_grp_match_arg *)arg;
+       return id == a->id && pdev->id == a->instance;
+}
+
+static int xroot_get_group(struct xroot *xr, int instance,
+                          struct platform_device **grpp)
+{
+       int rc = 0;
+       struct xrt_subdev_pool *grps = &xr->grps.pool;
+       struct device *dev = DEV(xr->pdev);
+       struct xroot_grp_match_arg arg = { XRT_SUBDEV_GRP, instance };
+
+       if (instance == XROOT_GRP_LAST) {
+               rc = xrt_subdev_pool_get(grps, XRT_SUBDEV_MATCH_NEXT,
+                                        *grpp, dev, grpp);
+       } else if (instance == XROOT_GRP_FIRST) {
+               rc = xrt_subdev_pool_get(grps, XRT_SUBDEV_MATCH_PREV,
+                                        *grpp, dev, grpp);
+       } else {
+               rc = xrt_subdev_pool_get(grps, xroot_grp_match,
+                                        &arg, dev, grpp);
+       }
+
+       if (rc && rc != -ENOENT)
+               xroot_err(xr, "failed to hold group %d: %d", instance, rc);
+       return rc;
+}
+
+static void xroot_put_group(struct xroot *xr, struct platform_device *grp)
+{
+       int inst = grp->id;
+       int rc = xrt_subdev_pool_put(&xr->grps.pool, grp, DEV(xr->pdev));
+
+       if (rc)
+               xroot_err(xr, "failed to release group %d: %d", inst, rc);
+}
+
+static int xroot_trigger_event(struct xroot *xr,
+                              struct xrt_event *e, bool async)
+{
+       struct xroot_evt *enew = vzalloc(sizeof(*enew));
+
+       if (!enew)
+               return -ENOMEM;
+
+       enew->evt = *e;
+       enew->async = async;
+       init_completion(&enew->comp);
+
+       mutex_lock(&xr->events.evt_lock);
+       list_add(&enew->list, &xr->events.evt_list);
+       mutex_unlock(&xr->events.evt_lock);
+
+       schedule_work(&xr->events.evt_work);
+
+       if (async)
+               return 0;
+
+       wait_for_completion(&enew->comp);
+       vfree(enew);
+       return 0;
+}
+
+static void
+xroot_group_trigger_event(struct xroot *xr, int inst, enum xrt_events e)
+{
+       int ret;
+       struct platform_device *pdev = NULL;
+       struct xrt_event evt = { 0 };
+
+       WARN_ON(inst < 0);
+       /* Only triggers subdev specific events. */
+       if (e != XRT_EVENT_POST_CREATION && e != XRT_EVENT_PRE_REMOVAL) {
+               xroot_err(xr, "invalid event %d", e);
+               return;
+       }
+
+       ret = xroot_get_group(xr, inst, &pdev);
+       if (ret)
+               return;
+
+       /* Triggers event for children, first. */
+       (void)xleaf_ioctl(pdev, XRT_GROUP_TRIGGER_EVENT, (void *)(uintptr_t)e);
+
+       /* Triggers event for itself. */
+       evt.xe_evt = e;
+       evt.xe_subdev.xevt_subdev_id = XRT_SUBDEV_GRP;
+       evt.xe_subdev.xevt_subdev_instance = inst;
+       (void)xroot_trigger_event(xr, &evt, false);
+
+       (void)xroot_put_group(xr, pdev);
+}
+
+int xroot_create_group(void *root, char *dtb)
+{
+       struct xroot *xr = (struct xroot *)root;
+       int ret;
+
+       atomic_inc(&xr->grps.bringup_pending);
+       ret = xrt_subdev_pool_add(&xr->grps.pool, XRT_SUBDEV_GRP,
+                                 xroot_root_cb, xr, dtb);
+       if (ret >= 0) {
+               schedule_work(&xr->grps.bringup_work);
+       } else {
+               atomic_dec(&xr->grps.bringup_pending);
+               atomic_inc(&xr->grps.bringup_failed);
+               xroot_err(xr, "failed to create group: %d", ret);
+       }
+       return ret;
+}
+EXPORT_SYMBOL_GPL(xroot_create_group);
+
+static int xroot_destroy_single_group(struct xroot *xr, int instance)
+{
+       struct platform_device *pdev = NULL;
+       int ret;
+
+       WARN_ON(instance < 0);
+       ret = xroot_get_group(xr, instance, &pdev);
+       if (ret)
+               return ret;
+
+       xroot_group_trigger_event(xr, instance, XRT_EVENT_PRE_REMOVAL);
+
+       /* Now tear down all children in this group. */
+       ret = xleaf_ioctl(pdev, XRT_GROUP_FINI_CHILDREN, NULL);
+       (void)xroot_put_group(xr, pdev);
+       if (!ret) {
+               ret = xrt_subdev_pool_del(&xr->grps.pool, XRT_SUBDEV_GRP,
+                                         instance);
+       }
+
+       return ret;
+}
+
+static int xroot_destroy_group(struct xroot *xr, int instance)
+{
+       struct platform_device *target = NULL;
+       struct platform_device *deps = NULL;
+       int ret;
+
+       WARN_ON(instance < 0);
+       /*
+        * Make sure target group exists and can't go away before
+        * we remove it's dependents
+        */
+       ret = xroot_get_group(xr, instance, &target);
+       if (ret)
+               return ret;
+
+       /*
+        * Remove all groups depend on target one.
+        * Assuming subdevs in higher group ID can depend on ones in
+        * lower ID groups, we remove them in the reservse order.
+        */
+       while (xroot_get_group(xr, XROOT_GRP_LAST, &deps) != -ENOENT) {
+               int inst = deps->id;
+
+               xroot_put_group(xr, deps);
+               if (instance == inst)
+                       break;
+               (void)xroot_destroy_single_group(xr, inst);
+               deps = NULL;
+       }
+
+       /* Now we can remove the target group. */
+       xroot_put_group(xr, target);
+       return xroot_destroy_single_group(xr, instance);
+}
+
+static int xroot_lookup_group(struct xroot *xr,
+                             struct xrt_root_ioctl_lookup_group *arg)
+{
+       int rc = -ENOENT;
+       struct platform_device *grp = NULL;
+
+       while (rc < 0 && xroot_get_group(xr, XROOT_GRP_LAST, &grp) != -ENOENT) {
+               if (arg->xpilp_match_cb(XRT_SUBDEV_GRP, grp,
+                                       arg->xpilp_match_arg)) {
+                       rc = grp->id;
+               }
+               xroot_put_group(xr, grp);
+       }
+       return rc;
+}
+
+static void xroot_event_work(struct work_struct *work)
+{
+       struct xroot_evt *tmp;
+       struct xroot *xr = container_of(work, struct xroot, events.evt_work);
+
+       mutex_lock(&xr->events.evt_lock);
+       while (!list_empty(&xr->events.evt_list)) {
+               tmp = list_first_entry(&xr->events.evt_list,
+                                      struct xroot_evt, list);
+               list_del(&tmp->list);
+               mutex_unlock(&xr->events.evt_lock);
+
+               (void)xrt_subdev_pool_handle_event(&xr->grps.pool, &tmp->evt);
+
+               if (tmp->async)
+                       vfree(tmp);
+               else
+                       complete(&tmp->comp);
+
+               mutex_lock(&xr->events.evt_lock);
+       }
+       mutex_unlock(&xr->events.evt_lock);
+}
+
+static void xroot_event_init(struct xroot *xr)
+{
+       INIT_LIST_HEAD(&xr->events.evt_list);
+       mutex_init(&xr->events.evt_lock);
+       INIT_WORK(&xr->events.evt_work, xroot_event_work);
+}
+
+static void xroot_event_fini(struct xroot *xr)
+{
+       flush_scheduled_work();
+       WARN_ON(!list_empty(&xr->events.evt_list));
+}
+
+static int xroot_get_leaf(struct xroot *xr, struct xrt_root_ioctl_get_leaf 
*arg)
+{
+       int rc = -ENOENT;
+       struct platform_device *grp = NULL;
+
+       while (rc && xroot_get_group(xr, XROOT_GRP_LAST, &grp) != -ENOENT) {
+               rc = xleaf_ioctl(grp, XRT_GROUP_GET_LEAF, arg);
+               xroot_put_group(xr, grp);
+       }
+       return rc;
+}
+
+static int xroot_put_leaf(struct xroot *xr, struct xrt_root_ioctl_put_leaf 
*arg)
+{
+       int rc = -ENOENT;
+       struct platform_device *grp = NULL;
+
+       while (rc && xroot_get_group(xr, XROOT_GRP_LAST, &grp) != -ENOENT) {
+               rc = xleaf_ioctl(grp, XRT_GROUP_PUT_LEAF, arg);
+               xroot_put_group(xr, grp);
+       }
+       return rc;
+}
+
+static int xroot_root_cb(struct device *dev, void *parg, u32 cmd, void *arg)
+{
+       struct xroot *xr = (struct xroot *)parg;
+       int rc = 0;
+
+       switch (cmd) {
+       /* Leaf actions. */
+       case XRT_ROOT_GET_LEAF: {
+               struct xrt_root_ioctl_get_leaf *getleaf =
+                       (struct xrt_root_ioctl_get_leaf *)arg;
+               rc = xroot_get_leaf(xr, getleaf);
+               break;
+       }
+       case XRT_ROOT_PUT_LEAF: {
+               struct xrt_root_ioctl_put_leaf *putleaf =
+                       (struct xrt_root_ioctl_put_leaf *)arg;
+               rc = xroot_put_leaf(xr, putleaf);
+               break;
+       }
+       case XRT_ROOT_GET_LEAF_HOLDERS: {
+               struct xrt_root_ioctl_get_holders *holders =
+                       (struct xrt_root_ioctl_get_holders *)arg;
+               rc = xrt_subdev_pool_get_holders(&xr->grps.pool,
+                                                holders->xpigh_pdev,
+                                                holders->xpigh_holder_buf,
+                                                holders->xpigh_holder_buf_len);
+               break;
+       }
+
+       /* Group actions. */
+       case XRT_ROOT_CREATE_GROUP:
+               rc = xroot_create_group(xr, (char *)arg);
+               break;
+       case XRT_ROOT_REMOVE_GROUP:
+               rc = xroot_destroy_group(xr, (int)(uintptr_t)arg);
+               break;
+       case XRT_ROOT_LOOKUP_GROUP: {
+               struct xrt_root_ioctl_lookup_group *getgrp =
+                       (struct xrt_root_ioctl_lookup_group *)arg;
+               rc = xroot_lookup_group(xr, getgrp);
+               break;
+       }
+       case XRT_ROOT_WAIT_GROUP_BRINGUP:
+               rc = xroot_wait_for_bringup(xr) ? 0 : -EINVAL;
+               break;
+
+       /* Event actions. */
+       case XRT_ROOT_EVENT:
+       case XRT_ROOT_EVENT_ASYNC: {
+               bool async = (cmd == XRT_ROOT_EVENT_ASYNC);
+               struct xrt_event *evt = (struct xrt_event *)arg;
+
+               rc = xroot_trigger_event(xr, evt, async);
+               break;
+       }
+
+       /* Device info. */
+       case XRT_ROOT_GET_RESOURCE: {
+               struct xrt_root_ioctl_get_res *res =
+                       (struct xrt_root_ioctl_get_res *)arg;
+               res->xpigr_res = xr->pdev->resource;
+               break;
+       }
+       case XRT_ROOT_GET_ID: {
+               struct xrt_root_ioctl_get_id *id =
+                       (struct xrt_root_ioctl_get_id *)arg;
+
+               id->xpigi_vendor_id = xr->pdev->vendor;
+               id->xpigi_device_id = xr->pdev->device;
+               id->xpigi_sub_vendor_id = xr->pdev->subsystem_vendor;
+               id->xpigi_sub_device_id = xr->pdev->subsystem_device;
+               break;
+       }
+
+       /* MISC generic PCIE driver functions. */
+       case XRT_ROOT_HOT_RESET: {
+               xr->pf_cb.xpc_hot_reset(xr->pdev);
+               break;
+       }
+       case XRT_ROOT_HWMON: {
+               struct xrt_root_ioctl_hwmon *hwmon =
+                       (struct xrt_root_ioctl_hwmon *)arg;
+
+               if (hwmon->xpih_register) {
+                       hwmon->xpih_hwmon_dev =
+                               hwmon_device_register_with_info(DEV(xr->pdev),
+                                                               
hwmon->xpih_name,
+                                                               
hwmon->xpih_drvdata,
+                                                               NULL,
+                                                               
hwmon->xpih_groups);
+               } else {
+                       (void)hwmon_device_unregister(hwmon->xpih_hwmon_dev);
+               }
+               break;
+       }
+
+       default:
+               xroot_err(xr, "unknown IOCTL cmd %d", cmd);
+               rc = -EINVAL;
+               break;
+       }
+
+       return rc;
+}
+
+static void xroot_bringup_group_work(struct work_struct *work)
+{
+       struct platform_device *pdev = NULL;
+       struct xroot *xr = container_of(work, struct xroot, grps.bringup_work);
+
+       while (xroot_get_group(xr, XROOT_GRP_FIRST, &pdev) != -ENOENT) {
+               int r, i;
+
+               i = pdev->id;
+               r = xleaf_ioctl(pdev, XRT_GROUP_INIT_CHILDREN, NULL);
+               (void)xroot_put_group(xr, pdev);
+               if (r == -EEXIST)
+                       continue; /* Already brough up, nothing to do. */
+               if (r)
+                       atomic_inc(&xr->grps.bringup_failed);
+
+               xroot_group_trigger_event(xr, i, XRT_EVENT_POST_CREATION);
+
+               if (atomic_dec_and_test(&xr->grps.bringup_pending))
+                       complete(&xr->grps.bringup_comp);
+       }
+}
+
+static void xroot_grps_init(struct xroot *xr)
+{
+       xrt_subdev_pool_init(DEV(xr->pdev), &xr->grps.pool);
+       INIT_WORK(&xr->grps.bringup_work, xroot_bringup_group_work);
+       atomic_set(&xr->grps.bringup_pending, 0);
+       atomic_set(&xr->grps.bringup_failed, 0);
+       init_completion(&xr->grps.bringup_comp);
+}
+
+static void xroot_grps_fini(struct xroot *xr)
+{
+       flush_scheduled_work();
+       xrt_subdev_pool_fini(&xr->grps.pool);
+}
+
+int xroot_add_vsec_node(void *root, char *dtb)
+{
+       struct xroot *xr = (struct xroot *)root;
+       struct device *dev = DEV(xr->pdev);
+       struct xrt_md_endpoint ep = { 0 };
+       int cap = 0, ret = 0;
+       u32 off_low, off_high, vsec_bar, header;
+       u64 vsec_off;
+
+       while ((cap = pci_find_next_ext_capability(xr->pdev, cap,
+                                                  PCI_EXT_CAP_ID_VNDR))) {
+               pci_read_config_dword(xr->pdev, cap + PCI_VNDR_HEADER, &header);
+               if (PCI_VNDR_HEADER_ID(header) == XRT_VSEC_ID)
+                       break;
+       }
+       if (!cap) {
+               xroot_info(xr, "No Vendor Specific Capability.");
+               return -ENOENT;
+       }
+
+       if (pci_read_config_dword(xr->pdev, cap + 8, &off_low) ||
+           pci_read_config_dword(xr->pdev, cap + 12, &off_high)) {
+               xroot_err(xr, "pci_read vendor specific failed.");
+               return -EINVAL;
+       }
+
+       ep.ep_name = XRT_MD_NODE_VSEC;
+       ret = xrt_md_add_endpoint(dev, dtb, &ep);
+       if (ret) {
+               xroot_err(xr, "add vsec metadata failed, ret %d", ret);
+               goto failed;
+       }
+
+       vsec_bar = cpu_to_be32(off_low & 0xf);
+       ret = xrt_md_set_prop(dev, dtb, XRT_MD_NODE_VSEC, NULL,
+                             XRT_MD_PROP_BAR_IDX, &vsec_bar, sizeof(vsec_bar));
+       if (ret) {
+               xroot_err(xr, "add vsec bar idx failed, ret %d", ret);
+               goto failed;
+       }
+
+       vsec_off = cpu_to_be64(((u64)off_high << 32) | (off_low & ~0xfU));
+       ret = xrt_md_set_prop(dev, dtb, XRT_MD_NODE_VSEC, NULL,
+                             XRT_MD_PROP_OFFSET, &vsec_off, sizeof(vsec_off));
+       if (ret) {
+               xroot_err(xr, "add vsec offset failed, ret %d", ret);
+               goto failed;
+       }
+
+failed:
+       return ret;
+}
+EXPORT_SYMBOL_GPL(xroot_add_vsec_node);
+
+int xroot_add_simple_node(void *root, char *dtb, const char *endpoint)
+{
+       struct xroot *xr = (struct xroot *)root;
+       struct device *dev = DEV(xr->pdev);
+       struct xrt_md_endpoint ep = { 0 };
+       int ret = 0;
+
+       ep.ep_name = endpoint;
+       ret = xrt_md_add_endpoint(dev, dtb, &ep);
+       if (ret)
+               xroot_err(xr, "add %s failed, ret %d", endpoint, ret);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(xroot_add_simple_node);
+
+bool xroot_wait_for_bringup(void *root)
+{
+       struct xroot *xr = (struct xroot *)root;
+
+       wait_for_completion(&xr->grps.bringup_comp);
+       return atomic_xchg(&xr->grps.bringup_failed, 0) == 0;
+}
+EXPORT_SYMBOL_GPL(xroot_wait_for_bringup);
+
+int xroot_probe(struct pci_dev *pdev, struct xroot_pf_cb *cb, void **root)
+{
+       struct device *dev = DEV(pdev);
+       struct xroot *xr = NULL;
+
+       dev_info(dev, "%s: probing...", __func__);
+
+       xr = devm_kzalloc(dev, sizeof(*xr), GFP_KERNEL);
+       if (!xr)
+               return -ENOMEM;
+
+       xr->pdev = pdev;
+       xr->pf_cb = *cb;
+       xroot_grps_init(xr);
+       xroot_event_init(xr);
+
+       *root = xr;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(xroot_probe);
+
+void xroot_remove(void *root)
+{
+       struct xroot *xr = (struct xroot *)root;
+       struct platform_device *grp = NULL;
+
+       xroot_info(xr, "leaving...");
+
+       if (xroot_get_group(xr, XROOT_GRP_FIRST, &grp) == 0) {
+               int instance = grp->id;
+
+               xroot_put_group(xr, grp);
+               (void)xroot_destroy_group(xr, instance);
+       }
+
+       xroot_event_fini(xr);
+       xroot_grps_fini(xr);
+}
+EXPORT_SYMBOL_GPL(xroot_remove);
+
+void xroot_broadcast(void *root, enum xrt_events evt)
+{
+       struct xroot *xr = (struct xroot *)root;
+       struct xrt_event e = { 0 };
+
+       /* Root pf driver only broadcasts below two events. */
+       if (evt != XRT_EVENT_POST_CREATION && evt != XRT_EVENT_PRE_REMOVAL) {
+               xroot_info(xr, "invalid event %d", evt);
+               return;
+       }
+
+       e.xe_evt = evt;
+       e.xe_subdev.xevt_subdev_id = XRT_ROOT;
+       e.xe_subdev.xevt_subdev_instance = 0;
+       (void)xroot_trigger_event(xr, &e, false);
+}
+EXPORT_SYMBOL_GPL(xroot_broadcast);
-- 
2.18.4

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