Re: [PATCH V5 XRT Alveo 07/20] fpga: xrt: root driver infrastructure

[Tom Rix <trix@redhat.com>]

On 4/27/21 1:54 PM, Lizhi Hou wrote:
> Contains common code for all root drivers and handles root calls from
> xrt drivers. This is part of root driver infrastructure.
>
> Signed-off-by: Sonal Santan <sonal.santan@xilinx.com>
> Signed-off-by: Max Zhen <max.zhen@xilinx.com>
> Signed-off-by: Lizhi Hou <lizhi.hou@xilinx.com>
> ---
>   drivers/fpga/xrt/include/events.h  |  45 +++
>   drivers/fpga/xrt/include/xroot.h   | 117 +++++++
>   drivers/fpga/xrt/lib/subdev_pool.h |  53 +++
>   drivers/fpga/xrt/lib/xroot.c       | 536 +++++++++++++++++++++++++++++
>   4 files changed, 751 insertions(+)
>   create mode 100644 drivers/fpga/xrt/include/events.h
>   create mode 100644 drivers/fpga/xrt/include/xroot.h
>   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..775171a47c8e
> --- /dev/null
> +++ b/drivers/fpga/xrt/include/events.h
> @@ -0,0 +1,45 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + *	Cheng Zhen <maxz@xilinx.com>
> + */
> +
> +#ifndef _XRT_EVENTS_H_
> +#define _XRT_EVENTS_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/xroot.h b/drivers/fpga/xrt/include/xroot.h
> new file mode 100644
> index 000000000000..56461bcb07a9
> --- /dev/null
> +++ b/drivers/fpga/xrt/include/xroot.h
> @@ -0,0 +1,117 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + *	Cheng Zhen <maxz@xilinx.com>
> + */
> +
> +#ifndef _XRT_ROOT_H_
> +#define _XRT_ROOT_H_
> +
> +#include "xdevice.h"
> +#include "subdev_id.h"
> +#include "events.h"
> +
> +typedef bool (*xrt_subdev_match_t)(enum xrt_subdev_id, struct xrt_device *, void *);
> +#define XRT_SUBDEV_MATCH_PREV	((xrt_subdev_match_t)-1)
> +#define XRT_SUBDEV_MATCH_NEXT	((xrt_subdev_match_t)-2)
> +
> +/*
> + * Root calls.
> + */
> +enum xrt_root_cmd {
> +	/* Leaf actions. */
> +	XRT_ROOT_GET_LEAF = 0,
> +	XRT_ROOT_PUT_LEAF,
> +	XRT_ROOT_GET_LEAF_HOLDERS,
> +
> +	/* Group actions. */
> +	XRT_ROOT_CREATE_GROUP,
> +	XRT_ROOT_REMOVE_GROUP,
> +	XRT_ROOT_LOOKUP_GROUP,
> +	XRT_ROOT_WAIT_GROUP_BRINGUP,
> +
> +	/* Event actions. */
> +	XRT_ROOT_EVENT_SYNC,
> +	XRT_ROOT_EVENT_ASYNC,
> +
> +	/* Device info. */
> +	XRT_ROOT_GET_RESOURCE,
> +	XRT_ROOT_GET_ID,
> +
> +	/* Misc. */
> +	XRT_ROOT_HOT_RESET,
> +	XRT_ROOT_HWMON,
> +};
> +
> +struct xrt_root_get_leaf {
> +	struct xrt_device *xpigl_caller_xdev;
> +	xrt_subdev_match_t xpigl_match_cb;
> +	void *xpigl_match_arg;
> +	struct xrt_device *xpigl_tgt_xdev;
> +};
> +
> +struct xrt_root_put_leaf {
> +	struct xrt_device *xpipl_caller_xdev;
> +	struct xrt_device *xpipl_tgt_xdev;
> +};
> +
> +struct xrt_root_lookup_group {
> +	struct xrt_device *xpilp_xdev; /* caller's xdev */
> +	xrt_subdev_match_t xpilp_match_cb;
> +	void *xpilp_match_arg;
> +	int xpilp_grp_inst;
> +};
> +
> +struct xrt_root_get_holders {
> +	struct xrt_device *xpigh_xdev; /* caller's xdev */
> +	char *xpigh_holder_buf;
> +	size_t xpigh_holder_buf_len;
> +};
> +
> +struct xrt_root_get_res {
> +	u32 xpigr_region_id;
> +	struct resource *xpigr_res;
> +};
> +
> +struct xrt_root_get_id {
> +	unsigned short  xpigi_vendor_id;
> +	unsigned short  xpigi_device_id;
> +	unsigned short  xpigi_sub_vendor_id;
> +	unsigned short  xpigi_sub_device_id;
> +};
> +
> +struct xrt_root_hwmon {
> +	bool xpih_register;
> +	const char *xpih_name;
> +	void *xpih_drvdata;
> +	const struct attribute_group **xpih_groups;
> +	struct device *xpih_hwmon_dev;
> +};
> +
> +/*
> + * Callback for leaf to make a root request. Arguments are: parent device, parent cookie, req,
> + * and arg.
> + */
> +typedef int (*xrt_subdev_root_cb_t)(struct device *, void *, u32, void *);
> +int xrt_subdev_root_request(struct xrt_device *self, u32 cmd, void *arg);
> +
> +/*
> + * Defines physical function (MPF / UPF) specific operations
> + * needed in common root driver.
> + */
> +struct xroot_physical_function_callback {
> +	void (*xpc_get_id)(struct device *dev, struct xrt_root_get_id *rid);
> +	int (*xpc_get_resource)(struct device *dev, struct xrt_root_get_res *res);
> +	void (*xpc_hot_reset)(struct device *dev);
> +};
> +
> +int xroot_probe(struct device *dev, struct xroot_physical_function_callback *cb, void **root);
> +void xroot_remove(void *root);
> +bool xroot_wait_for_bringup(void *root);
> +int xroot_create_group(void *xr, char *dtb);
> +int xroot_add_simple_node(void *root, char *dtb, const char *endpoint);
> +void xroot_broadcast(void *root, enum xrt_events evt);
> +
> +#endif	/* _XRT_ROOT_H_ */
> diff --git a/drivers/fpga/xrt/lib/subdev_pool.h b/drivers/fpga/xrt/lib/subdev_pool.h
> new file mode 100644
> index 000000000000..03f617d7ffd7
> --- /dev/null
> +++ b/drivers/fpga/xrt/lib/subdev_pool.h
> @@ -0,0 +1,53 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + *	Cheng Zhen <maxz@xilinx.com>
> + */
> +
> +#ifndef _XRT_SUBDEV_POOL_H_
> +#define _XRT_SUBDEV_POOL_H_
> +
> +#include <linux/device.h>
> +#include <linux/mutex.h>
> +#include "xroot.h"
> +
> +/*
> + * The struct xrt_subdev_pool 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 helper functions 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 xrt_device **xdevp);
> +int xrt_subdev_pool_put(struct xrt_subdev_pool *spool,
> +			struct xrt_device *xdev,
> +			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 xrt_device *xdev,
> +				    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..7b3e540dd6c0
> --- /dev/null
> +++ b/drivers/fpga/xrt/lib/xroot.c
> @@ -0,0 +1,536 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Xilinx Alveo FPGA Root Functions
> + *
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + *	Cheng Zhen <maxz@xilinx.com>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/hwmon.h>
> +#include "xroot.h"
> +#include "subdev_pool.h"
> +#include "group.h"
> +#include "metadata.h"
> +
> +#define xroot_err(xr, fmt, args...) dev_err((xr)->dev, "%s: " fmt, __func__, ##args)
> +#define xroot_warn(xr, fmt, args...) dev_warn((xr)->dev, "%s: " fmt, __func__, ##args)
> +#define xroot_info(xr, fmt, args...) dev_info((xr)->dev, "%s: " fmt, __func__, ##args)
> +#define xroot_dbg(xr, fmt, args...) dev_dbg((xr)->dev, "%s: " fmt, __func__, ##args)
> +
> +#define XROOT_GROUP_FIRST		(-1)
> +#define XROOT_GROUP_LAST		(-2)
> +
ok, vsec moved
> +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_groups {
> +	struct xrt_subdev_pool pool;
> +	struct work_struct bringup_work;
> +	atomic_t bringup_pending_cnt;
> +	atomic_t bringup_failed_cnt;

ok

Reviewed-by: Tom Rix <trix@redhat.com>

> +	struct completion bringup_comp;
> +};
> +
> +struct xroot {
> +	struct device *dev;
> +	struct xroot_events events;
> +	struct xroot_groups groups;
> +	struct xroot_physical_function_callback pf_cb;
> +};
> +
> +struct xroot_group_match_arg {
> +	enum xrt_subdev_id id;
> +	int instance;
> +};
> +
> +static bool xroot_group_match(enum xrt_subdev_id id, struct xrt_device *xdev, void *arg)
> +{
> +	struct xroot_group_match_arg *a = (struct xroot_group_match_arg *)arg;
> +
> +	/* xdev->instance is the instance of the subdev. */
> +	return id == a->id && xdev->instance == a->instance;
> +}
> +
> +static int xroot_get_group(struct xroot *xr, int instance, struct xrt_device **grpp)
> +{
> +	int rc = 0;
> +	struct xrt_subdev_pool *grps = &xr->groups.pool;
> +	struct device *dev = xr->dev;
> +	struct xroot_group_match_arg arg = { XRT_SUBDEV_GRP, instance };
> +
> +	if (instance == XROOT_GROUP_LAST) {
> +		rc = xrt_subdev_pool_get(grps, XRT_SUBDEV_MATCH_NEXT,
> +					 *grpp, dev, grpp);
> +	} else if (instance == XROOT_GROUP_FIRST) {
> +		rc = xrt_subdev_pool_get(grps, XRT_SUBDEV_MATCH_PREV,
> +					 *grpp, dev, grpp);
> +	} else {
> +		rc = xrt_subdev_pool_get(grps, xroot_group_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 xrt_device *grp)
> +{
> +	int inst = grp->instance;
> +	int rc = xrt_subdev_pool_put(&xr->groups.pool, grp, xr->dev);
> +
> +	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 xrt_device *xdev = 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, &xdev);
> +	if (ret)
> +		return;
> +
> +	/* Triggers event for children, first. */
> +	xleaf_call(xdev, 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;
> +	xroot_trigger_event(xr, &evt, false);
> +
> +	xroot_put_group(xr, xdev);
> +}
> +
> +int xroot_create_group(void *root, char *dtb)
> +{
> +	struct xroot *xr = (struct xroot *)root;
> +	int ret;
> +
> +	atomic_inc(&xr->groups.bringup_pending_cnt);
> +	ret = xrt_subdev_pool_add(&xr->groups.pool, XRT_SUBDEV_GRP, xroot_root_cb, xr, dtb);
> +	if (ret >= 0) {
> +		schedule_work(&xr->groups.bringup_work);
> +	} else {
> +		atomic_dec(&xr->groups.bringup_pending_cnt);
> +		atomic_inc(&xr->groups.bringup_failed_cnt);
> +		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 xrt_device *xdev = NULL;
> +	int ret;
> +
> +	WARN_ON(instance < 0);
> +	ret = xroot_get_group(xr, instance, &xdev);
> +	if (ret)
> +		return ret;
> +
> +	xroot_group_trigger_event(xr, instance, XRT_EVENT_PRE_REMOVAL);
> +
> +	/* Now tear down all children in this group. */
> +	ret = xleaf_call(xdev, XRT_GROUP_FINI_CHILDREN, NULL);
> +	xroot_put_group(xr, xdev);
> +	if (!ret)
> +		ret = xrt_subdev_pool_del(&xr->groups.pool, XRT_SUBDEV_GRP, instance);
> +
> +	return ret;
> +}
> +
> +static int xroot_destroy_group(struct xroot *xr, int instance)
> +{
> +	struct xrt_device *target = NULL;
> +	struct xrt_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_GROUP_LAST, &deps) != -ENOENT) {
> +		int inst = deps->instance;
> +
> +		xroot_put_group(xr, deps);
> +		/* Reached the target group instance, stop here. */
> +		if (instance == inst)
> +			break;
> +		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_lookup_group *arg)
> +{
> +	int rc = -ENOENT;
> +	struct xrt_device *grp = NULL;
> +
> +	while (rc < 0 && xroot_get_group(xr, XROOT_GROUP_LAST, &grp) != -ENOENT) {
> +		if (arg->xpilp_match_cb(XRT_SUBDEV_GRP, grp, arg->xpilp_match_arg))
> +			rc = grp->instance;
> +		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);
> +
> +		xrt_subdev_pool_handle_event(&xr->groups.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_get_leaf *arg)
> +{
> +	int rc = -ENOENT;
> +	struct xrt_device *grp = NULL;
> +
> +	while (rc && xroot_get_group(xr, XROOT_GROUP_LAST, &grp) != -ENOENT) {
> +		rc = xleaf_call(grp, XRT_GROUP_GET_LEAF, arg);
> +		xroot_put_group(xr, grp);
> +	}
> +	return rc;
> +}
> +
> +static int xroot_put_leaf(struct xroot *xr, struct xrt_root_put_leaf *arg)
> +{
> +	int rc = -ENOENT;
> +	struct xrt_device *grp = NULL;
> +
> +	while (rc && xroot_get_group(xr, XROOT_GROUP_LAST, &grp) != -ENOENT) {
> +		rc = xleaf_call(grp, XRT_GROUP_PUT_LEAF, arg);
> +		xroot_put_group(xr, grp);
> +	}
> +	return rc;
> +}
> +
> +static int xroot_root_cb(struct device *dev, void *parg, enum xrt_root_cmd cmd, void *arg)
> +{
> +	struct xroot *xr = (struct xroot *)parg;
> +	int rc = 0;
> +
> +	switch (cmd) {
> +	/* Leaf actions. */
> +	case XRT_ROOT_GET_LEAF: {
> +		struct xrt_root_get_leaf *getleaf = (struct xrt_root_get_leaf *)arg;
> +
> +		rc = xroot_get_leaf(xr, getleaf);
> +		break;
> +	}
> +	case XRT_ROOT_PUT_LEAF: {
> +		struct xrt_root_put_leaf *putleaf = (struct xrt_root_put_leaf *)arg;
> +
> +		rc = xroot_put_leaf(xr, putleaf);
> +		break;
> +	}
> +	case XRT_ROOT_GET_LEAF_HOLDERS: {
> +		struct xrt_root_get_holders *holders = (struct xrt_root_get_holders *)arg;
> +
> +		rc = xrt_subdev_pool_get_holders(&xr->groups.pool,
> +						 holders->xpigh_xdev,
> +						 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_lookup_group *getgrp = (struct xrt_root_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_SYNC:
> +	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_get_res *res = (struct xrt_root_get_res *)arg;
> +
> +		if (xr->pf_cb.xpc_get_resource) {
> +			rc = xr->pf_cb.xpc_get_resource(xr->dev, res);
> +		} else {
> +			xroot_err(xr, "get resource is not supported");
> +			rc = -EOPNOTSUPP;
> +		}
> +		break;
> +	}
> +	case XRT_ROOT_GET_ID: {
> +		struct xrt_root_get_id *id = (struct xrt_root_get_id *)arg;
> +
> +		if (xr->pf_cb.xpc_get_id)
> +			xr->pf_cb.xpc_get_id(xr->dev, id);
> +		else
> +			memset(id, 0, sizeof(*id));
> +		break;
> +	}
> +
> +	/* MISC generic root driver functions. */
> +	case XRT_ROOT_HOT_RESET: {
> +		if (xr->pf_cb.xpc_hot_reset) {
> +			xr->pf_cb.xpc_hot_reset(xr->dev);
> +		} else {
> +			xroot_err(xr, "hot reset is not supported");
> +			rc = -EOPNOTSUPP;
> +		}
> +		break;
> +	}
> +	case XRT_ROOT_HWMON: {
> +		struct xrt_root_hwmon *hwmon = (struct xrt_root_hwmon *)arg;
> +
> +		if (hwmon->xpih_register) {
> +			hwmon->xpih_hwmon_dev =
> +				hwmon_device_register_with_info(xr->dev,
> +								hwmon->xpih_name,
> +								hwmon->xpih_drvdata,
> +								NULL,
> +								hwmon->xpih_groups);
> +		} else {
> +			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 xrt_device *xdev = NULL;
> +	struct xroot *xr = container_of(work, struct xroot, groups.bringup_work);
> +
> +	while (xroot_get_group(xr, XROOT_GROUP_FIRST, &xdev) != -ENOENT) {
> +		int r, i;
> +
> +		i = xdev->instance;
> +		r = xleaf_call(xdev, XRT_GROUP_INIT_CHILDREN, NULL);
> +		xroot_put_group(xr, xdev);
> +		if (r == -EEXIST)
> +			continue; /* Already brough up, nothing to do. */
> +		if (r)
> +			atomic_inc(&xr->groups.bringup_failed_cnt);
> +
> +		xroot_group_trigger_event(xr, i, XRT_EVENT_POST_CREATION);
> +
> +		if (atomic_dec_and_test(&xr->groups.bringup_pending_cnt))
> +			complete(&xr->groups.bringup_comp);
> +	}
> +}
> +
> +static void xroot_groups_init(struct xroot *xr)
> +{
> +	xrt_subdev_pool_init(xr->dev, &xr->groups.pool);
> +	INIT_WORK(&xr->groups.bringup_work, xroot_bringup_group_work);
> +	atomic_set(&xr->groups.bringup_pending_cnt, 0);
> +	atomic_set(&xr->groups.bringup_failed_cnt, 0);
> +	init_completion(&xr->groups.bringup_comp);
> +}
> +
> +static void xroot_groups_fini(struct xroot *xr)
> +{
> +	flush_scheduled_work();
> +	xrt_subdev_pool_fini(&xr->groups.pool);
> +}
> +
> +int xroot_add_simple_node(void *root, char *dtb, const char *endpoint)
> +{
> +	struct xroot *xr = (struct xroot *)root;
> +	struct device *dev = xr->dev;
> +	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->groups.bringup_comp);
> +	return atomic_read(&xr->groups.bringup_failed_cnt) == 0;
> +}
> +EXPORT_SYMBOL_GPL(xroot_wait_for_bringup);
> +
> +int xroot_probe(struct device *dev, struct xroot_physical_function_callback *cb, void **root)
> +{
> +	struct xroot *xr = NULL;
> +
> +	dev_info(dev, "%s: probing...", __func__);
> +
> +	xr = devm_kzalloc(dev, sizeof(*xr), GFP_KERNEL);
> +	if (!xr)
> +		return -ENOMEM;
> +
> +	xr->dev = dev;
> +	xr->pf_cb = *cb;
> +	xroot_groups_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 xrt_device *grp = NULL;
> +
> +	xroot_info(xr, "leaving...");
> +
> +	if (xroot_get_group(xr, XROOT_GROUP_FIRST, &grp) == 0) {
> +		int instance = grp->instance;
> +
> +		xroot_put_group(xr, grp);
> +		xroot_destroy_group(xr, instance);
> +	}
> +
> +	xroot_event_fini(xr);
> +	xroot_groups_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;
> +	xroot_trigger_event(xr, &e, false);
> +}
> +EXPORT_SYMBOL_GPL(xroot_broadcast);