path: root/drivers/net/ethernet/intel/ice/ice_vf_lib.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2022, Intel Corporation. */

#include "ice_vf_lib_private.h"
#include "ice.h"
#include "ice_lib.h"
#include "ice_fltr.h"
#include "ice_virtchnl_allowlist.h"

/* Public functions which may be accessed by all driver files */

/**
 * ice_get_vf_by_id - Get pointer to VF by ID
 * @pf: the PF private structure
 * @vf_id: the VF ID to locate
 *
 * Locate and return a pointer to the VF structure associated with a given ID.
 * Returns NULL if the ID does not have a valid VF structure associated with
 * it.
 *
 * This function takes a reference to the VF, which must be released by
 * calling ice_put_vf() once the caller is finished accessing the VF structure
 * returned.
 */
struct ice_vf *ice_get_vf_by_id(struct ice_pf *pf, u16 vf_id)
{
	struct ice_vf *vf;

	rcu_read_lock();
	hash_for_each_possible_rcu(pf->vfs.table, vf, entry, vf_id) {
		if (vf->vf_id == vf_id) {
			struct ice_vf *found;

			if (kref_get_unless_zero(&vf->refcnt))
				found = vf;
			else
				found = NULL;

			rcu_read_unlock();
			return found;
		}
	}
	rcu_read_unlock();

	return NULL;
}

/**
 * ice_release_vf - Release VF associated with a refcount
 * @ref: the kref decremented to zero
 *
 * Callback function for kref_put to release a VF once its reference count has
 * hit zero.
 */
static void ice_release_vf(struct kref *ref)
{
	struct ice_vf *vf = container_of(ref, struct ice_vf, refcnt);

	vf->vf_ops->free(vf);
}

/**
 * ice_put_vf - Release a reference to a VF
 * @vf: the VF structure to decrease reference count on
 *
 * Decrease the reference count for a VF, and free the entry if it is no
 * longer in use.
 *
 * This must be called after ice_get_vf_by_id() once the reference to the VF
 * structure is no longer used. Otherwise, the VF structure will never be
 * freed.
 */
void ice_put_vf(struct ice_vf *vf)
{
	kref_put(&vf->refcnt, ice_release_vf);
}

/**
 * ice_has_vfs - Return true if the PF has any associated VFs
 * @pf: the PF private structure
 *
 * Return whether or not the PF has any allocated VFs.
 *
 * Note that this function only guarantees that there are no VFs at the point
 * of calling it. It does not guarantee that no more VFs will be added.
 */
bool ice_has_vfs(struct ice_pf *pf)
{
	/* A simple check that the hash table is not empty does not require
	 * the mutex or rcu_read_lock.
	 */
	return !hash_empty(pf->vfs.table);
}

/**
 * ice_get_num_vfs - Get number of allocated VFs
 * @pf: the PF private structure
 *
 * Return the total number of allocated VFs. NOTE: VF IDs are not guaranteed
 * to be contiguous. Do not assume that a VF ID is guaranteed to be less than
 * the output of this function.
 */
u16 ice_get_num_vfs(struct ice_pf *pf)
{
	struct ice_vf *vf;
	unsigned int bkt;
	u16 num_vfs = 0;

	rcu_read_lock();
	ice_for_each_vf_rcu(pf, bkt, vf)
		num_vfs++;
	rcu_read_unlock();

	return num_vfs;
}

/**
 * ice_get_vf_vsi - get VF's VSI based on the stored index
 * @vf: VF used to get VSI
 */
struct ice_vsi *ice_get_vf_vsi(struct ice_vf *vf)
{
	if (vf->lan_vsi_idx == ICE_NO_VSI)
		return NULL;

	return vf->pf->vsi[vf->lan_vsi_idx];
}

/**
 * ice_is_vf_disabled
 * @vf: pointer to the VF info
 *
 * If the PF has been disabled, there is no need resetting VF until PF is
 * active again. Similarly, if the VF has been disabled, this means something
 * else is resetting the VF, so we shouldn't continue.
 *
 * Returns true if the caller should consider the VF as disabled whether
 * because that single VF is explicitly disabled or because the PF is
 * currently disabled.
 */
bool ice_is_vf_disabled(struct ice_vf *vf)
{
	struct ice_pf *pf = vf->pf;

	return (test_bit(ICE_VF_DIS, pf->state) ||
		test_bit(ICE_VF_STATE_DIS, vf->vf_states));
}

/**
 * ice_wait_on_vf_reset - poll to make sure a given VF is ready after reset
 * @vf: The VF being resseting
 *
 * The max poll time is about ~800ms, which is about the maximum time it takes
 * for a VF to be reset and/or a VF driver to be removed.
 */
static void ice_wait_on_vf_reset(struct ice_vf *vf)
{
	int i;

	for (i = 0; i < ICE_MAX_VF_RESET_TRIES; i++) {
		if (test_bit(ICE_VF_STATE_INIT, vf->vf_states))
			break;
		msleep(ICE_MAX_VF_RESET_SLEEP_MS);
	}
}

/**
 * ice_check_vf_ready_for_cfg - check if VF is ready to be configured/queried
 * @vf: VF to check if it's ready to be configured/queried
 *
 * The purpose of this function is to make sure the VF is not in reset, not
 * disabled, and initialized so it can be configured and/or queried by a host
 * administrator.
 */
int ice_check_vf_ready_for_cfg(struct ice_vf *vf)
{
	ice_wait_on_vf_reset(vf);

	if (ice_is_vf_disabled(vf))
		return -EINVAL;

	if (ice_check_vf_init(vf))
		return -EBUSY;

	return 0;
}

/**
 * ice_trigger_vf_reset - Reset a VF on HW
 * @vf: pointer to the VF structure
 * @is_vflr: true if VFLR was issued, false if not
 * @is_pfr: true if the reset was triggered due to a previous PFR
 *
 * Trigger hardware to start a reset for a particular VF. Expects the caller
 * to wait the proper amount of time to allow hardware to reset the VF before
 * it cleans up and restores VF functionality.
 */
static void ice_trigger_vf_reset(struct ice_vf *vf, bool is_vflr, bool is_pfr)
{
	/* Inform VF that it is no longer active, as a warning */
	clear_bit(ICE_VF_STATE_ACTIVE, vf->vf_states);

	/* Disable VF's configuration API during reset. The flag is re-enabled
	 * when it's safe again to access VF's VSI.
	 */
	clear_bit(ICE_VF_STATE_INIT, vf->vf_states);

	/* VF_MBX_ARQLEN and VF_MBX_ATQLEN are cleared by PFR, so the driver
	 * needs to clear them in the case of VFR/VFLR. If this is done for
	 * PFR, it can