mei: implement client dma setup.

Implement HBM message protocol to setup and tear down
DMA buffer on behalf of an client. On top there DMA
buffer allocation and its life time management.

Signed-off-by: Alexander Usyskin <[e-mail]>
Signed-off-by: Tomas Winkler <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/mei/client.c

···
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/pm_runtime.h>
+#include <linux/dma-mapping.h>
 
 #include <linux/mei.h>
 
···
 	case MEI_FOP_DISCONNECT:
 	case MEI_FOP_NOTIFY_STOP:
 	case MEI_FOP_NOTIFY_START:
+	case MEI_FOP_DMA_MAP:
+	case MEI_FOP_DMA_UNMAP:
 		if (waitqueue_active(&cl->wait))
 			wake_up(&cl->wait);
 
···
 
 	list_for_each_entry(cl, &dev->file_list, link)
 		mei_cl_set_disconnected(cl);
+}
+
+static struct mei_cl *mei_cl_dma_map_find(struct mei_device *dev, u8 buffer_id)
+{
+	struct mei_cl *cl;
+
+	list_for_each_entry(cl, &dev->file_list, link)
+		if (cl->dma.buffer_id == buffer_id)
+			return cl;
+	return NULL;
+}
+
+/**
+ * mei_cl_irq_dma_map - send client dma map request in irq_thread context
+ *
+ * @cl: client
+ * @cb: callback block.
+ * @cmpl_list: complete list.
+ *
+ * Return: 0 on such and error otherwise.
+ */
+int mei_cl_irq_dma_map(struct mei_cl *cl, struct mei_cl_cb *cb,
+		       struct list_head *cmpl_list)
+{
+	struct mei_device *dev = cl->dev;
+	u32 msg_slots;
+	int slots;
+	int ret;
+
+	msg_slots = mei_hbm2slots(sizeof(struct hbm_client_dma_map_request));
+	slots = mei_hbuf_empty_slots(dev);
+	if (slots < 0)
+		return -EOVERFLOW;
+
+	if ((u32)slots < msg_slots)
+		return -EMSGSIZE;
+
+	ret = mei_hbm_cl_dma_map_req(dev, cl);
+	if (ret) {
+		cl->status = ret;
+		list_move_tail(&cb->list, cmpl_list);
+		return ret;
+	}
+
+	list_move_tail(&cb->list, &dev->ctrl_rd_list);
+	return 0;
+}
+
+/**
+ * mei_cl_irq_dma_unmap - send client dma unmap request in irq_thread context
+ *
+ * @cl: client
+ * @cb: callback block.
+ * @cmpl_list: complete list.
+ *
+ * Return: 0 on such and error otherwise.
+ */
+int mei_cl_irq_dma_unmap(struct mei_cl *cl, struct mei_cl_cb *cb,
+			 struct list_head *cmpl_list)
+{
+	struct mei_device *dev = cl->dev;
+	u32 msg_slots;
+	int slots;
+	int ret;
+
+	msg_slots = mei_hbm2slots(sizeof(struct hbm_client_dma_unmap_request));
+	slots = mei_hbuf_empty_slots(dev);
+	if (slots < 0)
+		return -EOVERFLOW;
+
+	if ((u32)slots < msg_slots)
+		return -EMSGSIZE;
+
+	ret = mei_hbm_cl_dma_unmap_req(dev, cl);
+	if (ret) {
+		cl->status = ret;
+		list_move_tail(&cb->list, cmpl_list);
+		return ret;
+	}
+
+	list_move_tail(&cb->list, &dev->ctrl_rd_list);
+	return 0;
+}
+
+static int mei_cl_dma_alloc(struct mei_cl *cl, u8 buf_id, size_t size)
+{
+	cl->dma.vaddr = dmam_alloc_coherent(cl->dev->dev, size,
+					    &cl->dma.daddr, GFP_KERNEL);
+	if (!cl->dma.vaddr)
+		return -ENOMEM;
+
+	cl->dma.buffer_id = buf_id;
+	cl->dma.size = size;
+
+	return 0;
+}
+
+static void mei_cl_dma_free(struct mei_cl *cl)
+{
+	cl->dma.buffer_id = 0;
+	dmam_free_coherent(cl->dev->dev,
+			   cl->dma.size, cl->dma.vaddr, cl->dma.daddr);
+	cl->dma.size = 0;
+	cl->dma.vaddr = NULL;
+	cl->dma.daddr = 0;
+}
+
+/**
+ * mei_cl_alloc_and_map - send client dma map request
+ *
+ * @cl: host client
+ * @fp: pointer to file structure
+ * @buffer_id: id of the mapped buffer
+ * @size: size of the buffer
+ *
+ * Locking: called under "dev->device_lock" lock
+ *
+ * Return:
+ * * -ENODEV
+ * * -EINVAL
+ * * -EOPNOTSUPP
+ * * -EPROTO
+ * * -ENOMEM;
+ */
+int mei_cl_dma_alloc_and_map(struct mei_cl *cl, const struct file *fp,
+			     u8 buffer_id, size_t size)
+{
+	struct mei_device *dev;
+	struct mei_cl_cb *cb;
+	int rets;
+
+	if (WARN_ON(!cl || !cl->dev))
+		return -ENODEV;
+
+	dev = cl->dev;
+
+	if (!dev->hbm_f_cd_supported) {
+		cl_dbg(dev, cl, "client dma is not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (buffer_id == 0)
+		return -EINVAL;
+
+	if (!mei_cl_is_connected(cl))
+		return -ENODEV;
+
+	if (cl->dma_mapped)
+		return -EPROTO;
+
+	if (mei_cl_dma_map_find(dev, buffer_id)) {
+		cl_dbg(dev, cl, "client dma with id %d is already allocated\n",
+		       cl->dma.buffer_id);
+		return -EPROTO;
+	}
+
+	rets = pm_runtime_get(dev->dev);
+	if (rets < 0 && rets != -EINPROGRESS) {
+		pm_runtime_put_noidle(dev->dev);
+		cl_err(dev, cl, "rpm: get failed %d\n", rets);
+		return rets;
+	}
+
+	rets = mei_cl_dma_alloc(cl, buffer_id, size);
+	if (rets) {
+		pm_runtime_put_noidle(dev->dev);
+		return rets;
+	}
+
+	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DMA_MAP, fp);
+	if (!cb) {
+		rets = -ENOMEM;
+		goto out;
+	}
+
+	if (mei_hbuf_acquire(dev)) {
+		if (mei_hbm_cl_dma_map_req(dev, cl)) {
+			rets = -ENODEV;
+			goto out;
+		}
+		list_move_tail(&cb->list, &dev->ctrl_rd_list);
+	}
+
+	mutex_unlock(&dev->device_lock);
+	wait_event_timeout(cl->wait,
+			   cl->dma_mapped ||
+			   cl->status ||
+			   !mei_cl_is_connected(cl),
+			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
+	mutex_lock(&dev->device_lock);
+
+	if (!cl->dma_mapped && !cl->status)
+		cl->status = -EFAULT;
+
+	rets = cl->status;
+
+out:
+	if (rets)
+		mei_cl_dma_free(cl);
+
+	cl_dbg(dev, cl, "rpm: autosuspend\n");
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
+
+	mei_io_cb_free(cb);
+	return rets;
+}
+
+/**
+ * mei_cl_unmap_and_free - send client dma unmap request
+ *
+ * @cl: host client
+ * @fp: pointer to file structure
+ *
+ * Locking: called under "dev->device_lock" lock
+ *
+ * Return: 0 on such and error otherwise.
+ */
+int mei_cl_dma_unmap(struct mei_cl *cl, const struct file *fp)
+{
+	struct mei_device *dev;
+	struct mei_cl_cb *cb;
+	int rets;
+
+	if (WARN_ON(!cl || !cl->dev))
+		return -ENODEV;
+
+	dev = cl->dev;
+
+	if (!dev->hbm_f_cd_supported) {
+		cl_dbg(dev, cl, "client dma is not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (!mei_cl_is_connected(cl))
+		return -ENODEV;
+
+	if (!cl->dma_mapped)
+		return -EPROTO;
+
+	rets = pm_runtime_get(dev->dev);
+	if (rets < 0 && rets != -EINPROGRESS) {
+		pm_runtime_put_noidle(dev->dev);
+		cl_err(dev, cl, "rpm: get failed %d\n", rets);
+		return rets;
+	}
+
+	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DMA_UNMAP, fp);
+	if (!cb) {
+		rets = -ENOMEM;
+		goto out;
+	}
+
+	if (mei_hbuf_acquire(dev)) {
+		if (mei_hbm_cl_dma_unmap_req(dev, cl)) {
+			rets = -ENODEV;
+			goto out;
+		}
+		list_move_tail(&cb->list, &dev->ctrl_rd_list);
+	}
+
+	mutex_unlock(&dev->device_lock);
+	wait_event_timeout(cl->wait,
+			   !cl->dma_mapped ||
+			   cl->status ||
+			   !mei_cl_is_connected(cl),
+			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
+	mutex_lock(&dev->device_lock);
+
+	if (cl->dma_mapped && !cl->status)
+		cl->status = -EFAULT;
+
+	rets = cl->status;
+
+	if (!rets)
+		mei_cl_dma_free(cl);
+out:
+	cl_dbg(dev, cl, "rpm: autosuspend\n");
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
+
+	mei_io_cb_free(cb);
+	return rets;
 }

drivers/misc/mei/client.h

···
 
 void mei_cl_all_disconnect(struct mei_device *dev);
 
+int mei_cl_irq_dma_map(struct mei_cl *cl, struct mei_cl_cb *cb,
+		       struct list_head *cmpl_list);
+int mei_cl_irq_dma_unmap(struct mei_cl *cl, struct mei_cl_cb *cb,
+			 struct list_head *cmpl_list);
+int mei_cl_dma_alloc_and_map(struct mei_cl *cl, const struct file *fp,
+			     u8 buffer_id, size_t size);
+int mei_cl_dma_unmap(struct mei_cl *cl, const struct file *fp);
+
 #define MEI_CL_FMT "cl:host=%02d me=%02d "
 #define MEI_CL_PRM(cl) (cl)->host_client_id, mei_cl_me_id(cl)
 

drivers/misc/mei/hbm.c

···
 }
 
 /**
+ * mei_hbm_cl_dma_map_req - send client dma map request
+ *
+ * @dev: the device structure
+ * @cl: mei host client
+ *
+ * Return: 0 on success and -EIO on write failure
+ */
+int mei_hbm_cl_dma_map_req(struct mei_device *dev, struct mei_cl *cl)
+{
+	struct mei_msg_hdr mei_hdr;
+	struct hbm_client_dma_map_request req;
+	int ret;
+
+	mei_hbm_hdr(&mei_hdr, sizeof(req));
+
+	memset(&req, 0, sizeof(req));
+
+	req.hbm_cmd = MEI_HBM_CLIENT_DMA_MAP_REQ_CMD;
+	req.client_buffer_id = cl->dma.buffer_id;
+	req.address_lsb = lower_32_bits(cl->dma.daddr);
+	req.address_msb = upper_32_bits(cl->dma.daddr);
+	req.size = cl->dma.size;
+
+	ret = mei_hbm_write_message(dev, &mei_hdr, &req);
+	if (ret)
+		dev_err(dev->dev, "dma map request failed: ret = %d\n", ret);
+
+	return ret;
+}
+
+/**
+ * mei_hbm_cl_dma_unmap_req - send client dma unmap request
+ *
+ * @dev: the device structure
+ * @cl: mei host client
+ *
+ * Return: 0 on success and -EIO on write failure
+ */
+int mei_hbm_cl_dma_unmap_req(struct mei_device *dev, struct mei_cl *cl)
+{
+	struct mei_msg_hdr mei_hdr;
+	struct hbm_client_dma_unmap_request req;
+	int ret;
+
+	mei_hbm_hdr(&mei_hdr, sizeof(req));
+
+	memset(&req, 0, sizeof(req));
+
+	req.hbm_cmd = MEI_HBM_CLIENT_DMA_UNMAP_REQ_CMD;
+	req.client_buffer_id = cl->dma.buffer_id;
+
+	ret = mei_hbm_write_message(dev, &mei_hdr, &req);
+	if (ret)
+		dev_err(dev->dev, "dma unmap request failed: ret = %d\n", ret);
+
+	return ret;
+}
+
+static void mei_hbm_cl_dma_map_res(struct mei_device *dev,
+				   struct hbm_client_dma_response *res)
+{
+	struct mei_cl *cl;
+	struct mei_cl_cb *cb, *next;
+
+	cl = NULL;
+	list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list, list) {
+		if (cb->fop_type != MEI_FOP_DMA_MAP)
+			continue;
+		if (!cb->cl->dma.buffer_id || cb->cl->dma_mapped)
+			continue;
+
+		cl = cb->cl;
+		break;
+	}
+	if (!cl)
+		return;
+
+	dev_dbg(dev->dev, "cl dma map result = %d\n", res->status);
+	cl->status = res->status;
+	if (!cl->status)
+		cl->dma_mapped = 1;
+	wake_up(&cl->wait);
+}
+
+static void mei_hbm_cl_dma_unmap_res(struct mei_device *dev,
+				     struct hbm_client_dma_response *res)
+{
+	struct mei_cl *cl;
+	struct mei_cl_cb *cb, *next;
+
+	cl = NULL;
+	list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list, list) {
+		if (cb->fop_type != MEI_FOP_DMA_UNMAP)
+			continue;
+		if (!cb->cl->dma.buffer_id || !cb->cl->dma_mapped)
+			continue;
+
+		cl = cb->cl;
+		break;
+	}
+	if (!cl)
+		return;
+
+	dev_dbg(dev->dev, "cl dma unmap result = %d\n", res->status);
+	cl->status = res->status;
+	if (!cl->status)
+		cl->dma_mapped = 0;
+	wake_up(&cl->wait);
+}
+
+/**
  * mei_hbm_prop_req - request property for a single client
  *
  * @dev: the device structure
···
 	struct mei_hbm_cl_cmd *cl_cmd;
 	struct hbm_client_connect_request *disconnect_req;
 	struct hbm_flow_control *fctrl;
+	struct hbm_client_dma_response *client_dma_res;
 
 	/* read the message to our buffer */
 	BUG_ON(hdr->length >= sizeof(dev->rd_msg_buf));
···
 	case MEI_HBM_NOTIFICATION_CMD:
 		dev_dbg(dev->dev, "hbm: notification\n");
 		mei_hbm_cl_notify(dev, cl_cmd);
+		break;
+
+	case MEI_HBM_CLIENT_DMA_MAP_RES_CMD:
+		dev_dbg(dev->dev, "hbm: client dma map response: message received.\n");
+		client_dma_res = (struct hbm_client_dma_response *)mei_msg;
+		mei_hbm_cl_dma_map_res(dev, client_dma_res);
+		break;
+
+	case MEI_HBM_CLIENT_DMA_UNMAP_RES_CMD:
+		dev_dbg(dev->dev, "hbm: client dma unmap response: message received.\n");
+		client_dma_res = (struct hbm_client_dma_response *)mei_msg;
+		mei_hbm_cl_dma_unmap_res(dev, client_dma_res);
 		break;
 
 	default:

drivers/misc/mei/hbm.h

···
 struct mei_device;
 struct mei_msg_hdr;
 struct mei_cl;
+struct mei_dma_data;
 
 /**
  * enum mei_hbm_state - host bus message protocol state
···
 void mei_hbm_pg_resume(struct mei_device *dev);
 int mei_hbm_cl_notify_req(struct mei_device *dev,
 			  struct mei_cl *cl, u8 request);
-
+int mei_hbm_cl_dma_map_req(struct mei_device *dev, struct mei_cl *cl);
+int mei_hbm_cl_dma_unmap_req(struct mei_device *dev, struct mei_cl *cl);
 #endif /* _MEI_HBM_H_ */
 

drivers/misc/mei/interrupt.c

···
 			if (ret)
 				return ret;
 			break;
+		case MEI_FOP_DMA_MAP:
+			ret = mei_cl_irq_dma_map(cl, cb, cmpl_list);
+			if (ret)
+				return ret;
+			break;
+		case MEI_FOP_DMA_UNMAP:
+			ret = mei_cl_irq_dma_unmap(cl, cb, cmpl_list);
+			if (ret)
+				return ret;
+			break;
 		default:
 			BUG();
 		}

drivers/misc/mei/mei_dev.h

···
  * @MEI_FOP_DISCONNECT_RSP: disconnect response
  * @MEI_FOP_NOTIFY_START:   start notification
  * @MEI_FOP_NOTIFY_STOP:    stop notification
+ * @MEI_FOP_DMA_MAP:   request client dma map
+ * @MEI_FOP_DMA_UNMAP: request client dma unmap
  */
 enum mei_cb_file_ops {
 	MEI_FOP_READ = 0,
···
 	MEI_FOP_DISCONNECT_RSP,
 	MEI_FOP_NOTIFY_START,
 	MEI_FOP_NOTIFY_STOP,
+	MEI_FOP_DMA_MAP,
+	MEI_FOP_DMA_UNMAP,
 };
 
 /**
···
 struct mei_msg_data {
 	size_t size;
 	unsigned char *data;
+};
+
+struct mei_dma_data {
+	u8 buffer_id;
+	void *vaddr;
+	dma_addr_t daddr;
+	size_t size;
 };
 
 /**
···
  * @rd_pending: pending read credits
  * @rd_completed_lock: protects rd_completed queue
  * @rd_completed: completed read
+ * @dma: dma settings
+ * @dma_mapped: dma buffer is currently mapped.
  *
  * @cldev: device on the mei client bus
  */
···
 	struct list_head rd_pending;
 	spinlock_t rd_completed_lock; /* protects rd_completed queue */
 	struct list_head rd_completed;
+	struct mei_dma_data dma;
+	u8 dma_mapped;
 
 	struct mei_cl_device *cldev;
 };