From: Phani R Burra <phani.r.bu...@intel.com>
Libie will now support control queue setup and configuration APIs. These
are mainly used for mailbox communication between drivers and control
plane.
Make use of the libeth_rx page pool support for managing controlq buffers.
Reviewed-by: Maciej Fijalkowski <maciej.fijalkow...@intel.com>
Signed-off-by: Phani R Burra <phani.r.bu...@intel.com>
Co-developed-by: Victor Raj <victor....@intel.com>
Signed-off-by: Victor Raj <victor....@intel.com>
Co-developed-by: Sridhar Samudrala <sridhar.samudr...@intel.com>
Signed-off-by: Sridhar Samudrala <sridhar.samudr...@intel.com>
Co-developed-by: Pavan Kumar Linga <pavan.kumar.li...@intel.com>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.li...@intel.com>
Co-developed-by: Larysa Zaremba <larysa.zare...@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zare...@intel.com>
---
drivers/net/ethernet/intel/libie/Kconfig | 8 +
drivers/net/ethernet/intel/libie/Makefile | 4 +
drivers/net/ethernet/intel/libie/controlq.c | 607 ++++++++++++++++++++
include/linux/intel/libie/controlq.h | 249 ++++++++
4 files changed, 868 insertions(+)
create mode 100644 drivers/net/ethernet/intel/libie/controlq.c
create mode 100644 include/linux/intel/libie/controlq.h
diff --git a/drivers/net/ethernet/intel/libie/Kconfig
b/drivers/net/ethernet/intel/libie/Kconfig
index e54a9ed24882..59c9018a0a16 100644
--- a/drivers/net/ethernet/intel/libie/Kconfig
+++ b/drivers/net/ethernet/intel/libie/Kconfig
@@ -15,6 +15,14 @@ config LIBIE_ADMINQ
Helper functions used by Intel Ethernet drivers for administration
queue command interface (aka adminq).
+config LIBIE_CP
+ tristate
+ select LIBETH
+ select LIBIE_PCI
+ help
+ Common helper routines to communicate with the device Control Plane
+ using virtchnl2 or related mailbox protocols.
+
config LIBIE_PCI
tristate
help
diff --git a/drivers/net/ethernet/intel/libie/Makefile
b/drivers/net/ethernet/intel/libie/Makefile
index 5f648d312a2a..65912a357886 100644
--- a/drivers/net/ethernet/intel/libie/Makefile
+++ b/drivers/net/ethernet/intel/libie/Makefile
@@ -9,6 +9,10 @@ obj-$(CONFIG_LIBIE_ADMINQ) += libie_adminq.o
libie_adminq-y := adminq.o
+obj-$(CONFIG_LIBIE_CP) += libie_cp.o
+
+libie_cp-y := controlq.o
+
obj-$(CONFIG_LIBIE_PCI) += libie_pci.o
libie_pci-y := pci.o
diff --git a/drivers/net/ethernet/intel/libie/controlq.c
b/drivers/net/ethernet/intel/libie/controlq.c
new file mode 100644
index 000000000000..80b0f1c2cc0a
--- /dev/null
+++ b/drivers/net/ethernet/intel/libie/controlq.c
@@ -0,0 +1,607 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2025 Intel Corporation */
+
+#include <linux/bitfield.h>
+#include <net/libeth/rx.h>
+
+#include <linux/intel/libie/controlq.h>
+
+#define LIBIE_CTLQ_DESC_QWORD0(sz) \
+ (LIBIE_CTLQ_DESC_FLAG_BUF | \
+ LIBIE_CTLQ_DESC_FLAG_RD | \
+ FIELD_PREP(LIBIE_CTLQ_DESC_DATA_LEN, sz))
+
+/**
+ * libie_ctlq_free_fq - free fill queue resources, including buffers
+ * @ctlq: Rx control queue whose resources need to be freed
+ */
+static void libie_ctlq_free_fq(struct libie_ctlq_info *ctlq)
+{
+ struct libeth_fq fq = {
+ .fqes = ctlq->rx_fqes,
+ .pp = ctlq->pp,
+ };
+
+ for (u32 ntc = ctlq->next_to_clean; ntc != ctlq->next_to_post; ) {
+ page_pool_put_full_netmem(fq.pp, fq.fqes[ntc].netmem, false);
+
+ if (++ntc >= ctlq->ring_len)
+ ntc = 0;
+ }
+
+ libeth_rx_fq_destroy(&fq);
+}
+
+/**
+ * libie_ctlq_init_fq - initialize fill queue for an Rx controlq
+ * @ctlq: control queue that needs a Rx buffer allocation
+ *
+ * Return: %0 on success, -%errno on failure
+ */
+static int libie_ctlq_init_fq(struct libie_ctlq_info *ctlq)
+{
+ struct libeth_fq fq = {
+ .count = ctlq->ring_len,
+ .truesize = LIBIE_CTLQ_MAX_BUF_LEN,
+ .nid = NUMA_NO_NODE,
+ .type = LIBETH_FQE_SHORT,
+ .hsplit = true,
+ .no_napi = true,
+ };
+ int err;
+
+ err = libeth_rx_fq_create(&fq, ctlq->dev);
+ if (err)
+ return err;
+
+ ctlq->pp = fq.pp;
+ ctlq->rx_fqes = fq.fqes;
+ ctlq->truesize = fq.truesize;
+
+ return 0;
+}
+
+/**
+ * libie_ctlq_reset_rx_desc - reset the descriptor with a new address
+ * @desc: descriptor to (re)initialize
+ * @addr: physical address to put into descriptor
+ * @mem_truesize: size of the accessible memory
+ */
+static void libie_ctlq_reset_rx_desc(struct libie_ctlq_desc *desc,
+ dma_addr_t addr, u32 mem_truesize)
+{
+ u64 qword;
+
+ *desc = (struct libie_ctlq_desc) {};
+ qword = LIBIE_CTLQ_DESC_QWORD0(mem_truesize);
+ desc->qword0 = cpu_to_le64(qword);
+
+ qword = FIELD_PREP(LIBIE_CTLQ_DESC_DATA_ADDR_HIGH,
+ upper_32_bits(addr)) |
+ FIELD_PREP(LIBIE_CTLQ_DESC_DATA_ADDR_LOW,
+ lower_32_bits(addr));
+ desc->qword3 = cpu_to_le64(qword);
+}
+
+/**
+ * libie_ctlq_post_rx_buffs - post buffers to descriptor ring
+ * @ctlq: control queue that requires Rx descriptor ring to be initialized with
+ * new Rx buffers
+ *
+ * The caller must make sure that calls to libie_ctlq_post_rx_buffs()
+ * and libie_ctlq_recv() for separate queues are either serialized
+ * or used under ctlq->lock.
+ *
+ * Return: %0 on success, -%ENOMEM if any buffer could not be allocated
+ */
+int libie_ctlq_post_rx_buffs(struct libie_ctlq_info *ctlq)
+{
+ u32 ntp = ctlq->next_to_post, ntc = ctlq->next_to_clean, num_to_post;
+ const struct libeth_fq_fp fq = {
+ .pp = ctlq->pp,
+ .fqes = ctlq->rx_fqes,
+ .truesize = ctlq->truesize,
+ .count = ctlq->ring_len,
+ };
+ int ret = 0;
+
+ num_to_post = (ntc > ntp ? 0 : ctlq->ring_len) + ntc - ntp - 1;
+
+ while (num_to_post--) {
+ dma_addr_t addr;
+
+ addr = libeth_rx_alloc(&fq, ntp);
+ if (unlikely(addr == DMA_MAPPING_ERROR)) {
+ ret = -ENOMEM;
+ goto post_bufs;
+ }
+
+ libie_ctlq_reset_rx_desc(&ctlq->descs[ntp], addr, fq.truesize);
+
+ if (unlikely(++ntp == ctlq->ring_len))
+ ntp = 0;
+ }
+
+post_bufs:
+ if (likely(ctlq->next_to_post != ntp)) {
+ ctlq->next_to_post = ntp;
+
+ writel(ntp, ctlq->reg.tail);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_NS_GPL(libie_ctlq_post_rx_buffs, "LIBIE_CP");
+
+/**
+ * libie_ctlq_free_tx_msgs - Free Tx control queue messages
+ * @ctlq: Tx control queue being destroyed
+ * @num_msgs: number of messages allocated so far
+ */
+static void libie_ctlq_free_tx_msgs(struct libie_ctlq_info *ctlq,
+ u32 num_msgs)
+{
+ for (u32 i = 0; i < num_msgs; i++)
+ kfree(ctlq->tx_msg[i]);
+
+ kvfree(ctlq->tx_msg);
+}
+
+/**
+ * libie_ctlq_alloc_tx_msgs - Allocate Tx control queue messages
+ * @ctlq: Tx control queue being created
+ *
+ * Return: %0 on success, -%ENOMEM on allocation error
+ */
+static int libie_ctlq_alloc_tx_msgs(struct libie_ctlq_info *ctlq)
+{
+ ctlq->tx_msg = kvcalloc(ctlq->ring_len,
+ sizeof(*ctlq->tx_msg), GFP_KERNEL);
+ if (!ctlq->tx_msg)
+ return -ENOMEM;
+
+ for (u32 i = 0; i < ctlq->ring_len; i++) {
+ ctlq->tx_msg[i] = kzalloc(sizeof(*ctlq->tx_msg[i]), GFP_KERNEL);
+
+ if (!ctlq->tx_msg[i]) {
+ libie_ctlq_free_tx_msgs(ctlq, i);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * libie_cp_free_dma_mem - Free the previously allocated DMA memory
+ * @dev: device information
+ * @mem: DMA memory information
+ */
+static void libie_cp_free_dma_mem(struct device *dev,
+ struct libie_cp_dma_mem *mem)
+{
+ dma_free_coherent(dev, mem->size, mem->va, mem->pa);
+ mem->va = NULL;
+}
+
+/**
+ * libie_ctlq_dealloc_ring_res - Free memory allocated for control queue
+ * @ctlq: control queue that requires its ring memory to be freed
+ *
+ * Free the memory used by the ring, buffers and other related structures.
+ */
+static void libie_ctlq_dealloc_ring_res(struct libie_ctlq_info *ctlq)
+{
+ struct libie_cp_dma_mem *dma = &ctlq->ring_mem;
+
+ if (ctlq->type == LIBIE_CTLQ_TYPE_TX)
+ libie_ctlq_free_tx_msgs(ctlq, ctlq->ring_len);
+ else
+ libie_ctlq_free_fq(ctlq);
+
+ libie_cp_free_dma_mem(ctlq->dev, dma);
+}
+
+/**
+ * libie_cp_alloc_dma_mem - Allocate a DMA memory
+ * @dev: device information
+ * @mem: memory for DMA information to be stored
+ * @size: size of the memory to allocate
+ *
+ * Return: virtual address of DMA memory or NULL.
+ */
+static void *libie_cp_alloc_dma_mem(struct device *dev,
+ struct libie_cp_dma_mem *mem, u32 size)
+{
+ size = ALIGN(size, SZ_4K);
+
+ mem->va = dma_alloc_coherent(dev, size, &mem->pa, GFP_KERNEL);
+ mem->size = size;
+
+ return mem->va;
+}
+
+/**
+ * libie_ctlq_alloc_queue_res - allocate memory for descriptor ring and bufs
+ * @ctlq: control queue that requires its ring resources to be allocated
+ *
+ * Return: %0 on success, -%errno on failure
+ */
+static int libie_ctlq_alloc_queue_res(struct libie_ctlq_info *ctlq)
+{
+ size_t size = array_size(ctlq->ring_len, sizeof(*ctlq->descs));
+ struct libie_cp_dma_mem *dma = &ctlq->ring_mem;
+ int err = -ENOMEM;
+
+ if (!libie_cp_alloc_dma_mem(ctlq->dev, dma, size))
+ return -ENOMEM;
+
+ ctlq->descs = dma->va;
+
+ if (ctlq->type == LIBIE_CTLQ_TYPE_TX) {
+ if (libie_ctlq_alloc_tx_msgs(ctlq))
+ goto free_dma_mem;
+ } else {
+ err = libie_ctlq_init_fq(ctlq);
+ if (err)
+ goto free_dma_mem;
+
+ err = libie_ctlq_post_rx_buffs(ctlq);
+ if (err) {
+ libie_ctlq_free_fq(ctlq);
+ goto free_dma_mem;
+ }
+ }
+
+ return 0;
+
+free_dma_mem:
+ libie_cp_free_dma_mem(ctlq->dev, dma);
+
+ return err;
+}
+
+/**
+ * libie_ctlq_init_regs - Initialize control queue registers
+ * @ctlq: control queue that needs to be initialized
+ *
+ * Initialize registers. The caller is expected to have already initialized the
+ * descriptor ring memory and buffer memory.
+ */
+static void libie_ctlq_init_regs(struct libie_ctlq_info *ctlq)
+{
+ u32 dword;
+
+ if (ctlq->type == VIRTCHNL2_QUEUE_TYPE_RX)
+ writel(ctlq->ring_len - 1, ctlq->reg.tail);
+
+ writel(0, ctlq->reg.head);
+ writel(lower_32_bits(ctlq->ring_mem.pa), ctlq->reg.addr_low);
+ writel(upper_32_bits(ctlq->ring_mem.pa), ctlq->reg.addr_high);
+
+ dword = FIELD_PREP(LIBIE_CTLQ_MBX_ATQ_LEN, ctlq->ring_len) |
+ ctlq->reg.len_ena_mask;
+ writel(dword, ctlq->reg.len);
+}
+
+/**
+ * libie_find_ctlq - find the controlq for the given id and type
+ * @ctx: controlq context structure
+ * @type: type of controlq to find
+ * @id: controlq id to find
+ *
+ * Return: control queue info pointer on success, NULL on failure
+ */
+struct libie_ctlq_info *libie_find_ctlq(struct libie_ctlq_ctx *ctx,
+ enum virtchnl2_queue_type type,
+ int id)
+{
+ struct libie_ctlq_info *cq;
+
+ guard(spinlock)(&ctx->ctlqs_lock);
+
+ list_for_each_entry(cq, &ctx->ctlqs, list)
+ if (cq->qid == id && cq->type == type)
+ return cq;
+
+ return NULL;
+}
+EXPORT_SYMBOL_NS_GPL(libie_find_ctlq, "LIBIE_CP");
+
+/**
+ * libie_ctlq_add - add one control queue
+ * @ctx: controlq context information
+ * @qinfo: information that requires for queue creation
+ *
+ * Allocate and initialize a control queue and add it to the control queue
list.
+ * The ctlq parameter will be allocated/initialized and passed back to the
+ * caller if no errors occur.
+ *
+ * Note: libie_ctlq_init must be called prior to any calls to libie_ctlq_add.
+ *
+ * Return: added control queue info pointer on success, error pointer on
failure
+ */
+static struct libie_ctlq_info *
+libie_ctlq_add(struct libie_ctlq_ctx *ctx,
+ const struct libie_ctlq_create_info *qinfo)
+{
+ struct libie_ctlq_info *ctlq;
+
+ if (qinfo->id != LIBIE_CTLQ_MBX_ID)
+ return ERR_PTR(-EOPNOTSUPP);
+
+ /* libie_ctlq_init was not called */
+ scoped_guard(spinlock, &ctx->ctlqs_lock)
+ if (!ctx->ctlqs.next)
+ return ERR_PTR(-EINVAL);
+
+ ctlq = kvzalloc(sizeof(*ctlq), GFP_KERNEL);
+ if (!ctlq)
+ return ERR_PTR(-ENOMEM);
+
+ ctlq->type = qinfo->type;
+ ctlq->qid = qinfo->id;
+ ctlq->ring_len = qinfo->len;
+ ctlq->dev = &ctx->mmio_info.pdev->dev;
+ ctlq->reg = qinfo->reg;
+
+ if (libie_ctlq_alloc_queue_res(ctlq)) {
+ kvfree(ctlq);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ libie_ctlq_init_regs(ctlq);
+
+ spin_lock_init(&ctlq->lock);
+
+ scoped_guard(spinlock, &ctx->ctlqs_lock)
+ list_add(&ctlq->list, &ctx->ctlqs);
+
+ return ctlq;
+}
+
+/**
+ * libie_ctlq_remove - deallocate and remove specified control queue
+ * @ctx: libie context information
+ * @ctlq: specific control queue that needs to be removed
+ */
+static void libie_ctlq_remove(struct libie_ctlq_ctx *ctx,
+ struct libie_ctlq_info *ctlq)
+{
+ scoped_guard(spinlock, &ctx->ctlqs_lock)
+ list_del(&ctlq->list);
+
+ libie_ctlq_dealloc_ring_res(ctlq);
+ kvfree(ctlq);
+}
+
+/**
+ * libie_ctlq_init - main initialization routine for all control queues
+ * @ctx: libie context information
+ * @qinfo: array of structs containing info for each queue to be initialized
+ * @numq: number of queues to initialize
+ *
+ * This initializes queue list and adds any number and any type of control
+ * queues. This is an all or nothing routine; if one fails, all previously
+ * allocated queues will be destroyed. This must be called prior to using
+ * the individual add/remove APIs.
+ *
+ * Return: %0 on success, -%errno on failure
+ */
+int libie_ctlq_init(struct libie_ctlq_ctx *ctx,
+ const struct libie_ctlq_create_info *qinfo,
+ u32 numq)
+{
+ INIT_LIST_HEAD(&ctx->ctlqs);
+ spin_lock_init(&ctx->ctlqs_lock);
+
+ for (u32 i = 0; i < numq; i++) {
+ struct libie_ctlq_info *ctlq;
+
+ ctlq = libie_ctlq_add(ctx, &qinfo[i]);
+ if (IS_ERR(ctlq)) {
+ libie_ctlq_deinit(ctx);
+ return PTR_ERR(ctlq);
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(libie_ctlq_init, "LIBIE_CP");
+
+/**
+ * libie_ctlq_deinit - destroy all control queues
+ * @ctx: libie CP context information
+ */
+void libie_ctlq_deinit(struct libie_ctlq_ctx *ctx)
+{
+ struct libie_ctlq_info *ctlq, *tmp;
+
+ list_for_each_entry_safe(ctlq, tmp, &ctx->ctlqs, list)
+ libie_ctlq_remove(ctx, ctlq);
+}
+EXPORT_SYMBOL_NS_GPL(libie_ctlq_deinit, "LIBIE_CP");
+
+/**
+ * libie_ctlq_tx_desc_from_msg - initialize a Tx descriptor from a message
+ * @desc: descriptor to be initialized
+ * @msg: filled control queue message
+ */
+static void libie_ctlq_tx_desc_from_msg(struct libie_ctlq_desc *desc,
+ const struct libie_ctlq_msg *msg)
+{
+ const struct libie_cp_dma_mem *dma = &msg->send_mem;
+ u64 qword;
+
+ qword = FIELD_PREP(LIBIE_CTLQ_DESC_FLAGS, msg->flags) |
+ FIELD_PREP(LIBIE_CTLQ_DESC_INFRA_OPCODE, msg->opcode) |
+ FIELD_PREP(LIBIE_CTLQ_DESC_PFID_VFID, msg->func_id);
+ desc->qword0 = cpu_to_le64(qword);
+
+ qword = FIELD_PREP(LIBIE_CTLQ_DESC_VIRTCHNL_OPCODE,
+ msg->chnl_opcode) |
+ FIELD_PREP(LIBIE_CTLQ_DESC_VIRTCHNL_MSG_RET_VAL,
+ msg->chnl_retval);
+ desc->qword1 = cpu_to_le64(qword);
+
+ qword = FIELD_PREP(LIBIE_CTLQ_DESC_MSG_PARAM0, msg->param0) |
+ FIELD_PREP(LIBIE_CTLQ_DESC_SW_COOKIE,
+ msg->sw_cookie) |
+ FIELD_PREP(LIBIE_CTLQ_DESC_VIRTCHNL_FLAGS,
+ msg->virt_flags);
+ desc->qword2 = cpu_to_le64(qword);
+
+ if (likely(msg->data_len)) {
+ desc->qword0 |=
+ cpu_to_le64(LIBIE_CTLQ_DESC_QWORD0(msg->data_len));
+ qword = FIELD_PREP(LIBIE_CTLQ_DESC_DATA_ADDR_HIGH,
+ upper_32_bits(dma->pa)) |
+ FIELD_PREP(LIBIE_CTLQ_DESC_DATA_ADDR_LOW,
+ lower_32_bits(dma->pa));
+ } else {
+ qword = msg->addr_param;
+ }
+
+ desc->qword3 = cpu_to_le64(qword);
+}
+
+/**
+ * libie_ctlq_send - send a message to Control Plane or Peer
+ * @ctlq: specific control queue which is used for sending a message
+ * @q_msg: array of queue messages to be sent
+ * @num_q_msg: number of messages to send on control queue
+ *
+ * The control queue will hold a reference to each send message until
+ * the completion for that message has been cleaned.
+ *
+ * The caller must hold ctlq->lock.
+ *
+ * Return: %0 on success, -%errno on failure.
+ */
+int libie_ctlq_send(struct libie_ctlq_info *ctlq,
+ struct libie_ctlq_msg *q_msg, u32 num_q_msg)
+{
+ u32 num_desc_avail, ntu;
+
+ ntu = ctlq->next_to_use;
+
+ num_desc_avail = (ctlq->next_to_clean > ntu ? 0 : ctlq->ring_len) +
+ ctlq->next_to_clean - ntu - 1;
+
+ if (num_desc_avail < num_q_msg)
+ return -EBUSY;
+
+ for (int i = 0; i < num_q_msg; i++) {
+ struct libie_ctlq_msg *msg = &q_msg[i];
+ struct libie_ctlq_desc *desc;
+
+ desc = &ctlq->descs[ntu];
+ libie_ctlq_tx_desc_from_msg(desc, msg);
+
+ if (unlikely(++ntu == ctlq->ring_len))
+ ntu = 0;
+ }
+ writel(ntu, ctlq->reg.tail);
+ ctlq->next_to_use = ntu;
+
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(libie_ctlq_send, "LIBIE_CP");
+
+/**
+ * libie_ctlq_fill_rx_msg - fill in a message from Rx descriptor and buffer
+ * @msg: message to be filled in
+ * @desc: received descriptor
+ * @rx_buf: fill queue buffer associated with the descriptor
+ */
+static void libie_ctlq_fill_rx_msg(struct libie_ctlq_msg *msg,
+ const struct libie_ctlq_desc *desc,
+ struct libeth_fqe *rx_buf)
+{
+ u64 qword = le64_to_cpu(desc->qword0);
+
+ msg->flags = FIELD_GET(LIBIE_CTLQ_DESC_FLAGS, qword);
+ msg->opcode = FIELD_GET(LIBIE_CTLQ_DESC_INFRA_OPCODE, qword);
+ msg->data_len = FIELD_GET(LIBIE_CTLQ_DESC_DATA_LEN, qword);
+ msg->hw_retval = FIELD_GET(LIBIE_CTLQ_DESC_HW_RETVAL, qword);
+
+ qword = le64_to_cpu(desc->qword1);
+ msg->chnl_opcode =
+ FIELD_GET(LIBIE_CTLQ_DESC_VIRTCHNL_OPCODE, qword);
+ msg->chnl_retval =
+ FIELD_GET(LIBIE_CTLQ_DESC_VIRTCHNL_MSG_RET_VAL, qword);
+
+ qword = le64_to_cpu(desc->qword2);
+ msg->param0 =
+ FIELD_GET(LIBIE_CTLQ_DESC_MSG_PARAM0, qword);
+ msg->sw_cookie =
+ FIELD_GET(LIBIE_CTLQ_DESC_SW_COOKIE, qword);
+ msg->virt_flags =
+ FIELD_GET(LIBIE_CTLQ_DESC_VIRTCHNL_FLAGS, qword);
+
+ if (likely(msg->data_len)) {
+ msg->recv_mem = (struct kvec) {
+ .iov_base = netmem_address(rx_buf->netmem),
+ .iov_len = msg->data_len,
+ };
+ libeth_rx_sync_for_cpu(rx_buf, msg->data_len);
+ } else {
+ msg->recv_mem = (struct kvec) {};
+ msg->addr_param = le64_to_cpu(desc->qword3);
+ page_pool_put_full_netmem(netmem_get_pp(rx_buf->netmem),
+ rx_buf->netmem, false);
+ }
+}
+
+/**
+ * libie_ctlq_recv - receive control queue message call back
+ * @ctlq: control queue that needs to processed for receive
+ * @msg: array of received control queue messages on this q;
+ * needs to be pre-allocated by caller for as many messages as requested
+ * @num_q_msg: number of messages that can be stored in msg buffer
+ *
+ * Called by interrupt handler or polling mechanism. Caller is expected
+ * to free buffers.
+ *
+ * The caller must make sure that calls to libie_ctlq_post_rx_buffs()
+ * and libie_ctlq_recv() for separate queues are either serialized
+ * or used under ctlq->lock.
+ *
+ * Return: number of messages received
+ */
+u32 libie_ctlq_recv(struct libie_ctlq_info *ctlq, struct libie_ctlq_msg *msg,
+ u32 num_q_msg)
+{
+ u32 ntc, i;
+
+ ntc = ctlq->next_to_clean;
+
+ for (i = 0; i < num_q_msg; i++) {
+ const struct libie_ctlq_desc *desc = &ctlq->descs[ntc];
+ struct libeth_fqe *rx_buf = &ctlq->rx_fqes[ntc];
+ u64 qword;
+
+ qword = le64_to_cpu(desc->qword0);
+ if (!FIELD_GET(LIBIE_CTLQ_DESC_FLAG_DD, qword))
+ break;
+
+ dma_rmb();
+
+ if (unlikely(FIELD_GET(LIBIE_CTLQ_DESC_FLAG_ERR, qword)))
+ break;
+
+ libie_ctlq_fill_rx_msg(&msg[i], desc, rx_buf);
+
+ if (unlikely(++ntc == ctlq->ring_len))
+ ntc = 0;
+ }
+
+ ctlq->next_to_clean = ntc;
+
+ return i;
+}
+EXPORT_SYMBOL_NS_GPL(libie_ctlq_recv, "LIBIE_CP");
+
+MODULE_DESCRIPTION("Control Plane communication API");
+MODULE_IMPORT_NS("LIBETH");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/intel/libie/controlq.h
b/include/linux/intel/libie/controlq.h
new file mode 100644
index 000000000000..534508fbb405
--- /dev/null
+++ b/include/linux/intel/libie/controlq.h
@@ -0,0 +1,249 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (C) 2025 Intel Corporation */
+
+#ifndef __LIBIE_CONTROLQ_H
+#define __LIBIE_CONTROLQ_H
+
+#include <net/libeth/rx.h>
+
+#include <linux/intel/libie/pci.h>
+#include <linux/intel/virtchnl2.h>
+
+/* Default mailbox control queue */
+#define LIBIE_CTLQ_MBX_ID -1
+#define LIBIE_CTLQ_MAX_BUF_LEN SZ_4K
+
+#define LIBIE_CTLQ_TYPE_TX 0
+#define LIBIE_CTLQ_TYPE_RX 1
+
+/* Opcode used to send controlq message to the control plane */
+#define LIBIE_CTLQ_SEND_MSG_TO_CP 0x801
+#define LIBIE_CTLQ_SEND_MSG_TO_PEER 0x804
+
+/**
+ * struct libie_ctlq_ctx - contains controlq info and MMIO region info
+ * @mmio_info: MMIO region info structure
+ * @ctlqs: list that stores all the control queues
+ * @ctlqs_lock: lock for control queue list
+ */
+struct libie_ctlq_ctx {
+ struct libie_mmio_info mmio_info;
+ struct list_head ctlqs;
+ spinlock_t ctlqs_lock; /* protects the ctlqs list */
+};
+
+/**
+ * struct libie_ctlq_reg - structure representing virtual addresses of the
+ * controlq registers and masks
+ * @head: controlq head register address
+ * @tail: controlq tail register address
+ * @len: register address to write controlq length and enable bit
+ * @addr_high: register address to write the upper 32b of ring physical address
+ * @addr_low: register address to write the lower 32b of ring physical address
+ * @len_mask: mask to read the controlq length
+ * @len_ena_mask: mask to write the controlq enable bit
+ * @head_mask: mask to read the head value
+ */
+struct libie_ctlq_reg {
+ void __iomem *head;
+ void __iomem *tail;
+ void __iomem *len;
+ void __iomem *addr_high;
+ void __iomem *addr_low;
+ u32 len_mask;
+ u32 len_ena_mask;
+ u32 head_mask;
+};
+
+/**
+ * struct libie_cp_dma_mem - structure for DMA memory
+ * @va: virtual address
+ * @pa: physical address
+ * @size: memory size
+ */
+struct libie_cp_dma_mem {
+ void *va;
+ dma_addr_t pa;
+ size_t size;
+};
+
+/**
+ * struct libie_ctlq_msg - control queue message data
+ * @flags: refer to 'Flags sub-structure' definitions
+ * @opcode: infrastructure message opcode
+ * @data_len: size of the payload
+ * @func_id: queue id for the secondary mailbox queue, 0 for default mailbox
+ * @hw_retval: execution status from the HW
+ * @chnl_opcode: virtchnl message opcode
+ * @chnl_retval: virtchnl return value
+ * @param0: indirect message raw parameter0
+ * @sw_cookie: used to verify the response of the sent virtchnl message
+ * @virt_flags: virtchnl capability flags
+ * @addr_param: additional parameters in place of the address, given no buffer
+ * @recv_mem: virtual address and size of the buffer that contains
+ * the indirect response
+ * @send_mem: physical and virtual address of the DMA buffer,
+ * used for sending
+ */
+struct libie_ctlq_msg {
+ u16 flags;
+ u16 opcode;
+ u16 data_len;
+ union {
+ u16 func_id;
+ u16 hw_retval;
+ };
+ u32 chnl_opcode;
+ u32 chnl_retval;
+ u32 param0;
+ u16 sw_cookie;
+ u16 virt_flags;
+ u64 addr_param;
+ union {
+ struct kvec recv_mem;
+ struct libie_cp_dma_mem send_mem;
+ };
+};
+
+/**
+ * struct libie_ctlq_create_info - control queue create information
+ * @type: control queue type (Rx or Tx)
+ * @id: queue offset passed as input, -1 for default mailbox
+ * @reg: registers accessed by control queue
+ * @len: controlq length
+ */
+struct libie_ctlq_create_info {
+ enum virtchnl2_queue_type type;
+ int id;
+ struct libie_ctlq_reg reg;
+ u16 len;
+};
+
+/**
+ * struct libie_ctlq_info - control queue information
+ * @list: used to add a controlq to the list of queues in libie_ctlq_ctx
+ * @type: control queue type
+ * @qid: queue identifier
+ * @lock: control queue lock
+ * @ring_mem: descrtiptor ring DMA memory
+ * @descs: array of descrtiptors
+ * @rx_fqes: array of controlq Rx buffers
+ * @tx_msg: Tx messages sent to hardware
+ * @reg: registers used by control queue
+ * @dev: device that owns this control queue
+ * @pp: page pool for controlq Rx buffers
+ * @truesize: size to allocate per buffer
+ * @next_to_use: next available slot to send buffer
+ * @next_to_clean: next descrtiptor to be cleaned
+ * @next_to_post: next available slot to post buffers to after receive
+ * @ring_len: length of the descriptor ring
+ */
+struct libie_ctlq_info {
+ struct list_head list;
+ enum virtchnl2_queue_type type;
+ int qid;
+ spinlock_t lock; /* for concurrent processing */
+ struct libie_cp_dma_mem ring_mem;
+ struct libie_ctlq_desc *descs;
+ union {
+ struct libeth_fqe *rx_fqes;
+ struct libie_ctlq_msg **tx_msg;
+ };
+ struct libie_ctlq_reg reg;
+ struct device *dev;
+ struct page_pool *pp;
+ u32 truesize;
+ u32 next_to_clean;
+ union {
+ u32 next_to_use;
+ u32 next_to_post;
+ };
+ u32 ring_len;
+};
+
+#define LIBIE_CTLQ_MBX_ATQ_LEN GENMASK(9, 0)
+
+/* Flags sub-structure
+ * |0 |1 |2 |3 |4 |5 |6 |7 |8 |9 |10 |11 |12 |13 |14 |15 |
+ * |DD |CMP|ERR| * RSV * |FTYPE | *RSV* |RD |VFC|BUF| HOST_ID |
+ */
+ /* libie controlq descriptor qword0 details */
+#define LIBIE_CTLQ_DESC_FLAG_DD BIT(0)
+#define LIBIE_CTLQ_DESC_FLAG_CMP BIT(1)
+#define LIBIE_CTLQ_DESC_FLAG_ERR BIT(2)
+#define LIBIE_CTLQ_DESC_FLAG_FTYPE_VM BIT(6)
+#define LIBIE_CTLQ_DESC_FLAG_FTYPE_PF BIT(7)
+#define LIBIE_CTLQ_DESC_FLAG_FTYPE GENMASK(7, 6)
+#define LIBIE_CTLQ_DESC_FLAG_RD BIT(10)
+#define LIBIE_CTLQ_DESC_FLAG_VFC BIT(11)
+#define LIBIE_CTLQ_DESC_FLAG_BUF BIT(12)
+#define LIBIE_CTLQ_DESC_FLAG_HOST_ID GENMASK(15, 13)
+
+#define LIBIE_CTLQ_DESC_FLAGS GENMASK(15, 0)
+#define LIBIE_CTLQ_DESC_INFRA_OPCODE GENMASK_ULL(31, 16)
+#define LIBIE_CTLQ_DESC_DATA_LEN GENMASK_ULL(47, 32)
+#define LIBIE_CTLQ_DESC_HW_RETVAL GENMASK_ULL(63, 48)
+
+#define LIBIE_CTLQ_DESC_PFID_VFID GENMASK_ULL(63, 48)
+
+/* libie controlq descriptor qword1 details */
+#define LIBIE_CTLQ_DESC_VIRTCHNL_OPCODE GENMASK(27, 0)
+#define LIBIE_CTLQ_DESC_VIRTCHNL_DESC_TYPE GENMASK_ULL(31, 28)
+#define LIBIE_CTLQ_DESC_VIRTCHNL_MSG_RET_VAL GENMASK_ULL(63, 32)
+
+/* libie controlq descriptor qword2 details */
+#define LIBIE_CTLQ_DESC_MSG_PARAM0 GENMASK_ULL(31, 0)
+#define LIBIE_CTLQ_DESC_SW_COOKIE GENMASK_ULL(47, 32)
+#define LIBIE_CTLQ_DESC_VIRTCHNL_FLAGS GENMASK_ULL(63, 48)
+
+/* libie controlq descriptor qword3 details */
+#define LIBIE_CTLQ_DESC_DATA_ADDR_HIGH GENMASK_ULL(31, 0)
+#define LIBIE_CTLQ_DESC_DATA_ADDR_LOW GENMASK_ULL(63, 32)
+
+/**
+ * struct libie_ctlq_desc - control queue descriptor format
+ * @qword0: flags, message opcode, data length etc
+ * @qword1: virtchnl opcode, descriptor type and return value
+ * @qword2: indirect message parameters
+ * @qword3: indirect message buffer address
+ */
+struct libie_ctlq_desc {
+ __le64 qword0;
+ __le64 qword1;
+ __le64 qword2;
+ __le64 qword3;
+};
+
+/**
+ * libie_ctlq_release_rx_buf - Release Rx buffer for a specific control queue
+ * @rx_buf: Rx buffer to be freed
+ *
+ * Driver uses this function to post back the Rx buffer after the usage.
+ */
+static inline void libie_ctlq_release_rx_buf(struct kvec *rx_buf)
+{
+ netmem_ref netmem;
+
+ if (!rx_buf->iov_base)
+ return;
+
+ netmem = virt_to_netmem(rx_buf->iov_base);
+ page_pool_put_full_netmem(netmem_get_pp(netmem), netmem, false);
+}
+
+int libie_ctlq_init(struct libie_ctlq_ctx *ctx,
+ const struct libie_ctlq_create_info *qinfo, u32 numq);
+void libie_ctlq_deinit(struct libie_ctlq_ctx *ctx);
+
+struct libie_ctlq_info *libie_find_ctlq(struct libie_ctlq_ctx *ctx,
+ enum virtchnl2_queue_type type,
+ int id);
+
+int libie_ctlq_send(struct libie_ctlq_info *ctlq,
+ struct libie_ctlq_msg *q_msg, u32 num_q_msg);
+u32 libie_ctlq_recv(struct libie_ctlq_info *ctlq, struct libie_ctlq_msg *msg,
+ u32 num_q_msg);
+
+int libie_ctlq_post_rx_buffs(struct libie_ctlq_info *ctlq);
+
+#endif /* __LIBIE_CONTROLQ_H */
--
2.47.0
