11 files changed, 507 insertions, 56 deletions

diff --git a/drivers/misc/mei/Makefile b/drivers/misc/mei/Makefile
index cd6825afa8e1..d9215fc4e499 100644
--- a/drivers/misc/mei/Makefile
+++ b/drivers/misc/mei/Makefile
@@ -9,6 +9,7 @@ mei-objs += hbm.o
 mei-objs += interrupt.o
 mei-objs += client.o
 mei-objs += main.o
+mei-objs += dma-ring.o
 mei-objs += bus.o
 mei-objs += bus-fixup.o
 mei-$(CONFIG_DEBUG_FS) += debugfs.o
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index ebdcf0b450e2..1fc8ea0f519b 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -318,23 +318,6 @@ void mei_me_cl_rm_all(struct mei_device *dev)
 }
 
 /**
- * mei_cl_cmp_id - tells if the clients are the same
- *
- * @cl1: host client 1
- * @cl2: host client 2
- *
- * Return: true  - if the clients has same host and me ids
- *         false - otherwise
- */
-static inline bool mei_cl_cmp_id(const struct mei_cl *cl1,
-				const struct mei_cl *cl2)
-{
-	return cl1 && cl2 &&
-		(cl1->host_client_id == cl2->host_client_id) &&
-		(mei_cl_me_id(cl1) == mei_cl_me_id(cl2));
-}
-
-/**
  * mei_io_cb_free - free mei_cb_private related memory
  *
  * @cb: mei callback struct
@@ -418,7 +401,7 @@ static void mei_io_list_flush_cl(struct list_head *head,
 	struct mei_cl_cb *cb, *next;
 
 	list_for_each_entry_safe(cb, next, head, list) {
-		if (mei_cl_cmp_id(cl, cb->cl))
+		if (cl == cb->cl)
 			list_del_init(&cb->list);
 	}
 }
@@ -435,7 +418,7 @@ static void mei_io_tx_list_free_cl(struct list_head *head,
 	struct mei_cl_cb *cb, *next;
 
 	list_for_each_entry_safe(cb, next, head, list) {
-		if (mei_cl_cmp_id(cl, cb->cl))
+		if (cl == cb->cl)
 			mei_tx_cb_dequeue(cb);
 	}
 }
@@ -478,7 +461,7 @@ struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,
 	if (length == 0)
 		return cb;
 
-	cb->buf.data = kmalloc(length, GFP_KERNEL);
+	cb->buf.data = kmalloc(roundup(length, MEI_SLOT_SIZE), GFP_KERNEL);
 	if (!cb->buf.data) {
 		mei_io_cb_free(cb);
 		return NULL;
@@ -1374,7 +1357,9 @@ int mei_cl_notify_request(struct mei_cl *cl,
 
 	mutex_unlock(&dev->device_lock);
 	wait_event_timeout(cl->wait,
-			   cl->notify_en == request || !mei_cl_is_connected(cl),
+			   cl->notify_en == request ||
+			   cl->status ||
+			   !mei_cl_is_connected(cl),
 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 	mutex_lock(&dev->device_lock);
 
@@ -1573,10 +1558,13 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 	struct mei_msg_hdr mei_hdr;
 	size_t hdr_len = sizeof(mei_hdr);
 	size_t len;
-	size_t hbuf_len;
+	size_t hbuf_len, dr_len;
 	int hbuf_slots;
+	u32 dr_slots;
+	u32 dma_len;
 	int rets;
 	bool first_chunk;
+	const void *data;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return -ENODEV;
@@ -1597,6 +1585,7 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 	}
 
 	len = buf->size - cb->buf_idx;
+	data = buf->data + cb->buf_idx;
 	hbuf_slots = mei_hbuf_empty_slots(dev);
 	if (hbuf_slots < 0) {
 		rets = -EOVERFLOW;
@@ -1604,6 +1593,8 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 	}
 
 	hbuf_len = mei_slots2data(hbuf_slots);
+	dr_slots = mei_dma_ring_empty_slots(dev);
+	dr_len = mei_slots2data(dr_slots);
 
 	mei_msg_hdr_init(&mei_hdr, cb);
 
@@ -1614,23 +1605,33 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 	if (len + hdr_len <= hbuf_len) {
 		mei_hdr.length = len;
 		mei_hdr.msg_complete = 1;
+	} else if (dr_slots && hbuf_len >= hdr_len + sizeof(dma_len)) {
+		mei_hdr.dma_ring = 1;
+		if (len > dr_len)
+			len = dr_len;
+		else
+			mei_hdr.msg_complete = 1;
+
+		mei_hdr.length = sizeof(dma_len);
+		dma_len = len;
+		data = &dma_len;
 	} else if ((u32)hbuf_slots == mei_hbuf_depth(dev)) {
-		mei_hdr.length = hbuf_len - hdr_len;
+		len = hbuf_len - hdr_len;
+		mei_hdr.length = len;
 	} else {
 		return 0;
 	}
 
-	cl_dbg(dev, cl, "buf: size = %zu idx = %zu\n",
-			cb->buf.size, cb->buf_idx);
+	if (mei_hdr.dma_ring)
+		mei_dma_ring_write(dev, buf->data + cb->buf_idx, len);
 
-	rets = mei_write_message(dev, &mei_hdr, hdr_len,
-				 buf->data + cb->buf_idx, mei_hdr.length);
+	rets = mei_write_message(dev, &mei_hdr, hdr_len, data, mei_hdr.length);
 	if (rets)
 		goto err;
 
 	cl->status = 0;
 	cl->writing_state = MEI_WRITING;
-	cb->buf_idx += mei_hdr.length;
+	cb->buf_idx += len;
 
 	if (first_chunk) {
 		if (mei_cl_tx_flow_ctrl_creds_reduce(cl)) {
@@ -1665,11 +1666,13 @@ ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
 	struct mei_msg_data *buf;
 	struct mei_msg_hdr mei_hdr;
 	size_t hdr_len = sizeof(mei_hdr);
-	size_t len;
-	size_t hbuf_len;
+	size_t len, hbuf_len, dr_len;
 	int hbuf_slots;
+	u32 dr_slots;
+	u32 dma_len;
 	ssize_t rets;
 	bool blocking;
+	const void *data;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return -ENODEV;
@@ -1681,10 +1684,12 @@ ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
 
 	buf = &cb->buf;
 	len = buf->size;
-	blocking = cb->blocking;
 
 	cl_dbg(dev, cl, "len=%zd\n", len);
 
+	blocking = cb->blocking;
+	data = buf->data;
+
 	rets = pm_runtime_get(dev->dev);
 	if (rets < 0 && rets != -EINPROGRESS) {
 		pm_runtime_put_noidle(dev->dev);
@@ -1721,16 +1726,32 @@ ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
 	}
 
 	hbuf_len = mei_slots2data(hbuf_slots);
+	dr_slots = mei_dma_ring_empty_slots(dev);
+	dr_len =  mei_slots2data(dr_slots);
 
 	if (len + hdr_len <= hbuf_len) {
 		mei_hdr.length = len;
 		mei_hdr.msg_complete = 1;
+	} else if (dr_slots && hbuf_len >= hdr_len + sizeof(dma_len)) {
+		mei_hdr.dma_ring = 1;
+		if (len > dr_len)
+			len = dr_len;
+		else
+			mei_hdr.msg_complete = 1;
+
+		mei_hdr.length = sizeof(dma_len);
+		dma_len = len;
+		data = &dma_len;
 	} else {
-		mei_hdr.length = hbuf_len - hdr_len;
+		len = hbuf_len - hdr_len;
+		mei_hdr.length = len;
 	}
 
+	if (mei_hdr.dma_ring)
+		mei_dma_ring_write(dev, buf->data, len);
+
 	rets = mei_write_message(dev, &mei_hdr, hdr_len,
-				 buf->data, mei_hdr.length);
+				 data, mei_hdr.length);
 	if (rets)
 		goto err;
 
@@ -1739,7 +1760,9 @@ ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
 		goto err;
 
 	cl->writing_state = MEI_WRITING;
-	cb->buf_idx = mei_hdr.length;
+	cb->buf_idx = len;
+	/* restore return value */
+	len = buf->size;
 
 out:
 	if (mei_hdr.msg_complete)
diff --git a/drivers/misc/mei/dma-ring.c b/drivers/misc/mei/dma-ring.c
new file mode 100644
index 000000000000..795641b82181
--- /dev/null
+++ b/drivers/misc/mei/dma-ring.c
@@ -0,0 +1,269 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved.
+ */
+#include <linux/dma-mapping.h>
+#include <linux/mei.h>
+
+#include "mei_dev.h"
+
+/**
+ * mei_dmam_dscr_alloc() - allocate a managed coherent buffer
+ *     for the dma descriptor
+ * @dev: mei_device
+ * @dscr: dma descriptor
+ *
+ * Return:
+ * * 0       - on success or zero allocation request
+ * * -EINVAL - if size is not power of 2
+ * * -ENOMEM - of allocation has failed
+ */
+static int mei_dmam_dscr_alloc(struct mei_device *dev,
+			       struct mei_dma_dscr *dscr)
+{
+	if (!dscr->size)
+		return 0;
+
+	if (WARN_ON(!is_power_of_2(dscr->size)))
+		return -EINVAL;
+
+	if (dscr->vaddr)
+		return 0;
+
+	dscr->vaddr = dmam_alloc_coherent(dev->dev, dscr->size, &dscr->daddr,
+					  GFP_KERNEL);
+	if (!dscr->vaddr)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/**
+ * mei_dmam_dscr_free() - free a managed coherent buffer
+ *     from the dma descriptor
+ * @dev: mei_device
+ * @dscr: dma descriptor
+ */
+static void mei_dmam_dscr_free(struct mei_device *dev,
+			       struct mei_dma_dscr *dscr)
+{
+	if (!dscr->vaddr)
+		return;
+
+	dmam_free_coherent(dev->dev, dscr->size, dscr->vaddr, dscr->daddr);
+	dscr->vaddr = NULL;
+}
+
+/**
+ * mei_dmam_ring_free() - free dma ring buffers
+ * @dev: mei device
+ */
+void mei_dmam_ring_free(struct mei_device *dev)
+{
+	int i;
+
+	for (i = 0; i < DMA_DSCR_NUM; i++)
+		mei_dmam_dscr_free(dev, &dev->dr_dscr[i]);
+}
+
+/**
+ * mei_dmam_ring_alloc() - allocate dma ring buffers
+ * @dev: mei device
+ *
+ * Return: -ENOMEM on allocation failure 0 otherwise
+ */
+int mei_dmam_ring_alloc(struct mei_device *dev)
+{
+	int i;
+
+	for (i = 0; i < DMA_DSCR_NUM; i++)
+		if (mei_dmam_dscr_alloc(dev, &dev->dr_dscr[i]))
+			goto err;
+
+	return 0;
+
+err:
+	mei_dmam_ring_free(dev);
+	return -ENOMEM;
+}
+
+/**
+ * mei_dma_ring_is_allocated() - check if dma ring is allocated
+ * @dev: mei device
+ *
+ * Return: true if dma ring is allocated
+ */
+bool mei_dma_ring_is_allocated(struct mei_device *dev)
+{
+	return !!dev->dr_dscr[DMA_DSCR_HOST].vaddr;
+}
+
+static inline
+struct hbm_dma_ring_ctrl *mei_dma_ring_ctrl(struct mei_device *dev)
+{
+	return (struct hbm_dma_ring_ctrl *)dev->dr_dscr[DMA_DSCR_CTRL].vaddr;
+}
+
+/**
+ * mei_dma_ring_reset() - reset the dma control block
+ * @dev: mei device
+ */
+void mei_dma_ring_reset(struct mei_device *dev)
+{
+	struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);
+
+	if (!ctrl)
+		return;
+
+	memset(ctrl, 0, sizeof(*ctrl));
+}
+
+/**
+ * mei_dma_copy_from() - copy from dma ring into buffer
+ * @dev: mei device
+ * @buf: data buffer
+ * @offset: offset in slots.
+ * @n: number of slots to copy.
+ */
+static size_t mei_dma_copy_from(struct mei_device *dev, unsigned char *buf,
+				u32 offset, u32 n)
+{
+	unsigned char *dbuf = dev->dr_dscr[DMA_DSCR_DEVICE].vaddr;
+
+	size_t b_offset = offset << 2;
+	size_t b_n = n << 2;
+
+	memcpy(buf, dbuf + b_offset, b_n);
+
+	return b_n;
+}
+
+/**
+ * mei_dma_copy_to() - copy to a buffer to the dma ring
+ * @dev: mei device
+ * @buf: data buffer
+ * @offset: offset in slots.
+ * @n: number of slots to copy.
+ */
+static size_t mei_dma_copy_to(struct mei_device *dev, unsigned char *buf,
+			      u32 offset, u32 n)
+{
+	unsigned char *hbuf = dev->dr_dscr[DMA_DSCR_HOST].vaddr;
+
+	size_t b_offset = offset << 2;
+	size_t b_n = n << 2;
+
+	memcpy(hbuf + b_offset, buf, b_n);
+
+	return b_n;
+}
+
+/**
+ * mei_dma_ring_read() - read data from the ring
+ * @dev: mei device
+ * @buf: buffer to read into: may be NULL in case of droping the data.
+ * @len: length to read.
+ */
+void mei_dma_ring_read(struct mei_device *dev, unsigned char *buf, u32 len)
+{
+	struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);
+	u32 dbuf_depth;
+	u32 rd_idx, rem, slots;
+
+	if (WARN_ON(!ctrl))
+		return;
+
+	dev_dbg(dev->dev, "reading from dma %u bytes\n", len);
+
+	if (!len)
+		return;
+
+	dbuf_depth = dev->dr_dscr[DMA_DSCR_DEVICE].size >> 2;
+	rd_idx = READ_ONCE(ctrl->dbuf_rd_idx) & (dbuf_depth - 1);
+	slots = mei_data2slots(len);
+
+	/* if buf is NULL we drop the packet by advancing the pointer.*/
+	if (!buf)
+		goto out;
+
+	if (rd_idx + slots > dbuf_depth) {
+		buf += mei_dma_copy_from(dev, buf, rd_idx, dbuf_depth - rd_idx);
+		rem = slots - (dbuf_depth - rd_idx);
+		rd_idx = 0;
+	} else {
+		rem = slots;
+	}
+
+	mei_dma_copy_from(dev, buf, rd_idx, rem);
+out:
+	WRITE_ONCE(ctrl->dbuf_rd_idx, ctrl->dbuf_rd_idx + slots);
+}
+
+static inline u32 mei_dma_ring_hbuf_depth(struct mei_device *dev)
+{
+	return dev->dr_dscr[DMA_DSCR_HOST].size >> 2;
+}
+
+/**
+ * mei_dma_ring_empty_slots() - calaculate number of empty slots in dma ring
+ * @dev: mei_device
+ *
+ * Return: number of empty slots
+ */
+u32 mei_dma_ring_empty_slots(struct mei_device *dev)
+{
+	struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);
+	u32 wr_idx, rd_idx, hbuf_depth, empty;
+
+	if (!mei_dma_ring_is_allocated(dev))
+		return 0;
+
+	if (WARN_ON(!ctrl))
+		return 0;
+
+	/* easier to work in slots */
+	hbuf_depth = mei_dma_ring_hbuf_depth(dev);
+	rd_idx = READ_ONCE(ctrl->hbuf_rd_idx);
+	wr_idx = READ_ONCE(ctrl->hbuf_wr_idx);
+
+	if (rd_idx > wr_idx)
+		empty = rd_idx - wr_idx;
+	else
+		empty = hbuf_depth - (wr_idx - rd_idx);
+
+	return empty;
+}
+
+/**
+ * mei_dma_ring_write - write data to dma ring host buffer
+ *
+ * @dev: mei_device
+ * @buf: data will be written
+ * @len: data length
+ */
+void mei_dma_ring_write(struct mei_device *dev, unsigned char *buf, u32 len)
+{
+	struct hbm_dma_ring_ctrl *ctrl = mei_dma_ring_ctrl(dev);
+	u32 hbuf_depth;
+	u32 wr_idx, rem, slots;
+
+	if (WARN_ON(!ctrl))
+		return;
+
+	dev_dbg(dev->dev, "writing to dma %u bytes\n", len);
+	hbuf_depth = mei_dma_ring_hbuf_depth(dev);
+	wr_idx = READ_ONCE(ctrl->hbuf_wr_idx) & (hbuf_depth - 1);
+	slots = mei_data2slots(len);
+
+	if (wr_idx + slots > hbuf_depth) {
+		buf += mei_dma_copy_to(dev, buf, wr_idx, hbuf_depth - wr_idx);
+		rem = slots - (hbuf_depth - wr_idx);
+		wr_idx = 0;
+	} else {
+		rem = slots;
+	}
+
+	mei_dma_copy_to(dev, buf, wr_idx, rem);
+
+	WRITE_ONCE(ctrl->hbuf_wr_idx, ctrl->hbuf_wr_idx + slots);
+}
diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index e56f3e72d57a..78c26cebf5d4 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -65,6 +65,7 @@ const char *mei_hbm_state_str(enum mei_hbm_state state)
 	MEI_HBM_STATE(IDLE);
 	MEI_HBM_STATE(STARTING);
 	MEI_HBM_STATE(STARTED);
+	MEI_HBM_STATE(DR_SETUP);
 	MEI_HBM_STATE(ENUM_CLIENTS);
 	MEI_HBM_STATE(CLIENT_PROPERTIES);
 	MEI_HBM_STATE(STOPPED);
@@ -296,6 +297,48 @@ int mei_hbm_start_req(struct mei_device *dev)
 }
 
 /**
+ * mei_hbm_dma_setup_req() - setup DMA request
+ * @dev: the device structure
+ *
+ * Return: 0 on success and < 0 on failure
+ */
+static int mei_hbm_dma_setup_req(struct mei_device *dev)
+{
+	struct mei_msg_hdr mei_hdr;
+	struct hbm_dma_setup_request req;
+	const size_t len = sizeof(struct hbm_dma_setup_request);
+	unsigned int i;
+	int ret;
+
+	mei_hbm_hdr(&mei_hdr, len);
+
+	memset(&req, 0, len);
+	req.hbm_cmd = MEI_HBM_DMA_SETUP_REQ_CMD;
+	for (i = 0; i < DMA_DSCR_NUM; i++) {
+		phys_addr_t paddr;
+
+		paddr = dev->dr_dscr[i].daddr;
+		req.dma_dscr[i].addr_hi = upper_32_bits(paddr);
+		req.dma_dscr[i].addr_lo = lower_32_bits(paddr);
+		req.dma_dscr[i].size = dev->dr_dscr[i].size;
+	}
+
+	mei_dma_ring_reset(dev);
+
+	ret = mei_hbm_write_message(dev, &mei_hdr, &req);
+	if (ret) {
+		dev_err(dev->dev, "dma setup request write failed: ret = %d.\n",
+			ret);
+		return ret;
+	}
+
+	dev->hbm_state = MEI_HBM_DR_SETUP;
+	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
+	mei_schedule_stall_timer(dev);
+	return 0;
+}
+
+/**
  * mei_hbm_enum_clients_req - sends enumeration client request message.
  *
  * @dev: the device structure
@@ -1044,6 +1087,7 @@ int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
 	struct hbm_host_version_response *version_res;
 	struct hbm_props_response *props_res;
 	struct hbm_host_enum_response *enum_res;
+	struct hbm_dma_setup_response *dma_setup_res;
 	struct hbm_add_client_request *add_cl_req;
 	int ret;
 
@@ -1108,14 +1152,52 @@ int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
 			return -EPROTO;
 		}
 
-		if (mei_hbm_enum_clients_req(dev)) {
-			dev_err(dev->dev, "hbm: start: failed to send enumeration request\n");
-			return -EIO;
+		if (dev->hbm_f_dr_supported) {
+			if (mei_dmam_ring_alloc(dev))
+				dev_info(dev->dev, "running w/o dma ring\n");
+			if (mei_dma_ring_is_allocated(dev)) {
+				if (mei_hbm_dma_setup_req(dev))
+					return -EIO;
+
+				wake_up(&dev->wait_hbm_start);
+				break;
+			}
 		}
 
+		dev->hbm_f_dr_supported = 0;
+		mei_dmam_ring_free(dev);
+
+		if (mei_hbm_enum_clients_req(dev))
+			return -EIO;
+
 		wake_up(&dev->wait_hbm_start);
 		break;
 
+	case MEI_HBM_DMA_SETUP_RES_CMD:
+		dev_dbg(dev->dev, "hbm: dma setup response: message received.\n");
+
+		dev->init_clients_timer = 0;
+
+		if (dev->hbm_state != MEI_HBM_DR_SETUP) {
+			dev_err(dev->dev, "hbm: dma setup response: state mismatch, [%d, %d]\n",
+				dev->dev_state, dev->hbm_state);
+			return -EPROTO;
+		}
+
+		dma_setup_res = (struct hbm_dma_setup_response *)mei_msg;
+
+		if (dma_setup_res->status) {
+			dev_info(dev->dev, "hbm: dma setup response: failure = %d %s\n",
+				 dma_setup_res->status,
+				 mei_hbm_status_str(dma_setup_res->status));
+			dev->hbm_f_dr_supported = 0;
+			mei_dmam_ring_free(dev);
+		}
+
+		if (mei_hbm_enum_clients_req(dev))
+			return -EIO;
+		break;
+
 	case CLIENT_CONNECT_RES_CMD:
 		dev_dbg(dev->dev, "hbm: client connect response: message received.\n");
 		mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_CONNECT);
@@ -1271,8 +1353,8 @@ int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
 		break;
 
 	default:
-		BUG();
-		break;
+		WARN(1, "hbm: wrong command %d\n", mei_msg->hbm_cmd);
+		return -EPROTO;
 
 	}
 	return 0;
diff --git a/drivers/misc/mei/hbm.h b/drivers/misc/mei/hbm.h
index a2025a5083a3..0171a7e79bab 100644
--- a/drivers/misc/mei/hbm.h
+++ b/drivers/misc/mei/hbm.h
@@ -26,6 +26,7 @@ struct mei_cl;
  *
  * @MEI_HBM_IDLE : protocol not started
  * @MEI_HBM_STARTING : start request message was sent
+ * @MEI_HBM_DR_SETUP : dma ring setup request message was sent
  * @MEI_HBM_ENUM_CLIENTS : enumeration request was sent
  * @MEI_HBM_CLIENT_PROPERTIES : acquiring clients properties
  * @MEI_HBM_STARTED : enumeration was completed
@@ -34,6 +35,7 @@ struct mei_cl;
 enum mei_hbm_state {
 	MEI_HBM_IDLE = 0,
 	MEI_HBM_STARTING,
+	MEI_HBM_DR_SETUP,
 	MEI_HBM_ENUM_CLIENTS,
 	MEI_HBM_CLIENT_PROPERTIES,
 	MEI_HBM_STARTED,
diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 0759c3a668de..3fbbadfa2ae1 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -1471,15 +1471,21 @@ struct mei_device *mei_me_dev_init(struct pci_dev *pdev,
 {
 	struct mei_device *dev;
 	struct mei_me_hw *hw;
+	int i;
 
 	dev = devm_kzalloc(&pdev->dev, sizeof(struct mei_device) +
 			   sizeof(struct mei_me_hw), GFP_KERNEL);
 	if (!dev)
 		return NULL;
+
 	hw = to_me_hw(dev);
 
+	for (i = 0; i < DMA_DSCR_NUM; i++)
+		dev->dr_dscr[i].size = cfg->dma_size[i];
+
 	mei_device_init(dev, &pdev->dev, &mei_me_hw_ops);
 	hw->cfg = cfg;
+
 	return dev;
 }
 
diff --git a/drivers/misc/mei/hw.h b/drivers/misc/mei/hw.h
index 65655925791a..2b7f7677f8cc 100644
--- a/drivers/misc/mei/hw.h
+++ b/drivers/misc/mei/hw.h
@@ -35,7 +35,7 @@
 /*
  * MEI Version
  */
-#define HBM_MINOR_VERSION                   0
+#define HBM_MINOR_VERSION                   1
 #define HBM_MAJOR_VERSION                   2
 
 /*
@@ -206,6 +206,7 @@ enum  mei_cl_disconnect_status {
  * @dma_ring: message is on dma ring
  * @internal: message is internal
  * @msg_complete: last packet of the message
+ * @extension: extension of the header
  */
 struct mei_msg_hdr {
 	u32 me_addr:8;
@@ -215,8 +216,11 @@ struct mei_msg_hdr {
 	u32 dma_ring:1;
 	u32 internal:1;
 	u32 msg_complete:1;
+	u32 extension[0];
 } __packed;
 
+#define MEI_MSG_HDR_MAX 2
+
 struct mei_bus_message {
 	u8 hbm_cmd;
 	u8 data[0];
@@ -512,4 +516,27 @@ struct hbm_dma_setup_response {
 	u8 reserved[2];
 } __packed;
 
+/**
+ * struct mei_dma_ring_ctrl - dma ring control block
+ *
+ * @hbuf_wr_idx: host circular buffer write index in slots
+ * @reserved1: reserved for alignment
+ * @hbuf_rd_idx: host circular buffer read index in slots
+ * @reserved2: reserved for alignment
+ * @dbuf_wr_idx: device circular buffer write index in slots
+ * @reserved3: reserved for alignment
+ * @dbuf_rd_idx: device circular buffer read index in slots
+ * @reserved4: reserved for alignment
+ */
+struct hbm_dma_ring_ctrl {
+	u32 hbuf_wr_idx;
+	u32 reserved1;
+	u32 hbuf_rd_idx;
+	u32 reserved2;
+	u32 dbuf_wr_idx;
+	u32 reserved3;
+	u32 dbuf_rd_idx;
+	u32 reserved4;
+} __packed;
+
 #endif
diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index 4888ebc076b7..eb026e2a0537 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -151,7 +151,7 @@ int mei_reset(struct mei_device *dev)
 
 	mei_hbm_reset(dev);
 
-	dev->rd_msg_hdr = 0;
+	memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
 
 	if (ret) {
 		dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 5a661cbdf2ae..055c2d89b310 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -75,6 +75,8 @@ static inline int mei_cl_hbm_equal(struct mei_cl *cl,
  */
 static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
 {
+	if (hdr->dma_ring)
+		mei_dma_ring_read(dev, NULL, hdr->extension[0]);
 	/*
 	 * no need to check for size as it is guarantied
 	 * that length fits into rd_msg_buf
@@ -100,6 +102,7 @@ static int mei_cl_irq_read_msg(struct mei_cl *cl,
 	struct mei_device *dev = cl->dev;
 	struct mei_cl_cb *cb;
 	size_t buf_sz;
+	u32 length;
 
 	cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
 	if (!cb) {
@@ -119,25 +122,31 @@ static int mei_cl_irq_read_msg(struct mei_cl *cl,
 		goto discard;
 	}
 
-	buf_sz = mei_hdr->length + cb->buf_idx;
+	length = mei_hdr->dma_ring ? mei_hdr->extension[0] : mei_hdr->length;
+
+	buf_sz = length + cb->buf_idx;
 	/* catch for integer overflow */
 	if (buf_sz < cb->buf_idx) {
 		cl_err(dev, cl, "message is too big len %d idx %zu\n",
-		       mei_hdr->length, cb->buf_idx);
+		       length, cb->buf_idx);
 		cb->status = -EMSGSIZE;
 		goto discard;
 	}
 
 	if (cb->buf.size < buf_sz) {
 		cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
-			cb->buf.size, mei_hdr->length, cb->buf_idx);
+			cb->buf.size, length, cb->buf_idx);
 		cb->status = -EMSGSIZE;
 		goto discard;
 	}
 
+	if (mei_hdr->dma_ring)
+		mei_dma_ring_read(dev, cb->buf.data + cb->buf_idx, length);
+
+	/*  for DMA read 0 length to generate an interrupt to the device */
 	mei_read_slots(dev, cb->buf.data + cb->buf_idx, mei_hdr->length);
 
-	cb->buf_idx += mei_hdr->length;
+	cb->buf_idx += length;
 
 	if (mei_hdr->msg_complete) {
 		cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
@@ -247,6 +256,9 @@ static inline int hdr_is_valid(u32 msg_hdr)
 	if (!msg_hdr || mei_hdr->reserved)
 		return -EBADMSG;
 
+	if (mei_hdr->dma_ring && mei_hdr->length != MEI_SLOT_SIZE)
+		return -EBADMSG;
+
 	return 0;
 }
 
@@ -267,20 +279,20 @@ int mei_irq_read_handler(struct mei_device *dev,
 	struct mei_cl *cl;
 	int ret;
 
-	if (!dev->rd_msg_hdr) {
-		dev->rd_msg_hdr = mei_read_hdr(dev);
+	if (!dev->rd_msg_hdr[0]) {
+		dev->rd_msg_hdr[0] = mei_read_hdr(dev);
 		(*slots)--;
 		dev_dbg(dev->dev, "slots =%08x.\n", *slots);
 
-		ret = hdr_is_valid(dev->rd_msg_hdr);
+		ret = hdr_is_valid(dev->rd_msg_hdr[0]);
 		if (ret) {
 			dev_err(dev->dev, "corrupted message header 0x%08X\n",
-				dev->rd_msg_hdr);
+				dev->rd_msg_hdr[0]);
 			goto end;
 		}
 	}
 
-	mei_hdr = (struct mei_msg_hdr *)&dev->rd_msg_hdr;
+	mei_hdr = (struct mei_msg_hdr *)dev->rd_msg_hdr;
 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
 
 	if (mei_slots2data(*slots) < mei_hdr->length) {
@@ -291,6 +303,12 @@ int mei_irq_read_handler(struct mei_device *dev,
 		goto end;
 	}
 
+	if (mei_hdr->dma_ring) {
+		dev->rd_msg_hdr[1] = mei_read_hdr(dev);
+		(*slots)--;
+		mei_hdr->length = 0;
+	}
+
 	/*  HBM message */
 	if (hdr_is_hbm(mei_hdr)) {
 		ret = mei_hbm_dispatch(dev, mei_hdr);
@@ -324,7 +342,7 @@ int mei_irq_read_handler(struct mei_device *dev,
 			goto reset_slots;
 		}
 		dev_err(dev->dev, "no destination client found 0x%08X\n",
-				dev->rd_msg_hdr);
+				dev->rd_msg_hdr[0]);
 		ret = -EBADMSG;
 		goto end;
 	}
@@ -334,9 +352,8 @@ int mei_irq_read_handler(struct mei_device *dev,
 
 reset_slots:
 	/* reset the number of slots and header */
+	memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
 	*slots = mei_count_full_read_slots(dev);
-	dev->rd_msg_hdr = 0;
-
 	if (*slots == -EOVERFLOW) {
 		/* overflow - reset */
 		dev_err(dev->dev, "resetting due to slots overflow.\n");
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 377397e1b5a5..685b78ce30a5 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -122,6 +122,19 @@ struct mei_msg_data {
 	unsigned char *data;
 };
 
+/**
+ * struct mei_dma_dscr - dma address descriptor
+ *
+ * @vaddr: dma buffer virtual address
+ * @daddr: dma buffer physical address
+ * @size : dma buffer size
+ */
+struct mei_dma_dscr {
+	void *vaddr;
+	dma_addr_t daddr;
+	size_t size;
+};
+
 /* Maximum number of processed FW status registers */
 #define MEI_FW_STATUS_MAX 6
 /* Minimal  buffer for FW status string (8 bytes in dw + space or '\0') */
@@ -409,6 +422,7 @@ struct mei_fw_version {
  * @rd_msg_hdr  : read message header storage
  *
  * @hbuf_is_ready : query if the host host/write buffer is ready
+ * @dr_dscr: DMA ring descriptors: TX, RX, and CTRL
  *
  * @version     : HBM protocol version in use
  * @hbm_f_pg_supported  : hbm feature pgi protocol
@@ -483,11 +497,13 @@ struct mei_device {
 #endif /* CONFIG_PM */
 
 	unsigned char rd_msg_buf[MEI_RD_MSG_BUF_SIZE];
-	u32 rd_msg_hdr;
+	u32 rd_msg_hdr[MEI_MSG_HDR_MAX];
 
 	/* write buffer */
 	bool hbuf_is_ready;
 
+	struct mei_dma_dscr dr_dscr[DMA_DSCR_NUM];
+
 	struct hbm_version version;
 	unsigned int hbm_f_pg_supported:1;
 	unsigned int hbm_f_dc_supported:1;
@@ -578,6 +594,14 @@ int mei_restart(struct mei_device *dev);
 void mei_stop(struct mei_device *dev);
 void mei_cancel_work(struct mei_device *dev);
 
+int mei_dmam_ring_alloc(struct mei_device *dev);
+void mei_dmam_ring_free(struct mei_device *dev);
+bool mei_dma_ring_is_allocated(struct mei_device *dev);
+void mei_dma_ring_reset(struct mei_device *dev);
+void mei_dma_ring_read(struct mei_device *dev, unsigned char *buf, u32 len);
+void mei_dma_ring_write(struct mei_device *dev, unsigned char *buf, u32 len);
+u32 mei_dma_ring_empty_slots(struct mei_device *dev);
+
 /*
  *  MEI interrupt functions prototype
  */
diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c
index ea4e152270a3..73ace2d59dea 100644
--- a/drivers/misc/mei/pci-me.c
+++ b/drivers/misc/mei/pci-me.c
@@ -98,9 +98,9 @@ static const struct pci_device_id mei_me_pci_tbl[] = {
 	{MEI_PCI_DEVICE(MEI_DEV_ID_KBP, MEI_ME_PCH8_CFG)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_KBP_2, MEI_ME_PCH8_CFG)},
 
-	{MEI_PCI_DEVICE(MEI_DEV_ID_CNP_LP, MEI_ME_PCH8_CFG)},
+	{MEI_PCI_DEVICE(MEI_DEV_ID_CNP_LP, MEI_ME_PCH12_CFG)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_CNP_LP_4, MEI_ME_PCH8_CFG)},
-	{MEI_PCI_DEVICE(MEI_DEV_ID_CNP_H, MEI_ME_PCH8_CFG)},
+	{MEI_PCI_DEVICE(MEI_DEV_ID_CNP_H, MEI_ME_PCH12_CFG)},
 	{MEI_PCI_DEVICE(MEI_DEV_ID_CNP_H_4, MEI_ME_PCH8_CFG)},
 
 	/* required last entry */