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Commit 3e833295 authored by Samuel Ortiz's avatar Samuel Ortiz Committed by Greg Kroah-Hartman
Browse files

mei: bus: Initial implementation for I/O routines

parent 333e4ee0
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+226 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/slab.h>
@@ -25,6 +26,8 @@
#include <linux/mei_cl_bus.h>

#include "mei_dev.h"
#include "hw-me.h"
#include "client.h"

#define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
#define to_mei_cl_device(d) container_of(d, struct mei_cl_device, dev)
@@ -81,6 +84,11 @@ static int mei_cl_device_remove(struct device *dev)
	if (!device || !dev->driver)
		return 0;

	if (device->event_cb) {
		device->event_cb = NULL;
		cancel_work_sync(&device->event_work);
	}

	driver = to_mei_cl_driver(dev->driver);
	if (!driver->remove) {
		dev->driver = NULL;
@@ -196,3 +204,221 @@ void mei_cl_driver_unregister(struct mei_cl_driver *driver)
	pr_debug("mei: driver [%s] unregistered\n", driver->driver.name);
}
EXPORT_SYMBOL_GPL(mei_cl_driver_unregister);

int __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length)
{
	struct mei_device *dev;
	struct mei_msg_hdr mei_hdr;
	struct mei_cl_cb *cb;
	int me_cl_id, err;

	if (WARN_ON(!cl || !cl->dev))
		return -ENODEV;

	if (cl->state != MEI_FILE_CONNECTED)
		return -ENODEV;

	cb = mei_io_cb_init(cl, NULL);
	if (!cb)
		return -ENOMEM;

	err = mei_io_cb_alloc_req_buf(cb, length);
	if (err < 0) {
		mei_io_cb_free(cb);
		return err;
	}

	memcpy(cb->request_buffer.data, buf, length);
	cb->fop_type = MEI_FOP_WRITE;

	dev = cl->dev;

	mutex_lock(&dev->device_lock);

	/* Check if we have an ME client device */
	me_cl_id = mei_me_cl_by_id(dev, cl->me_client_id);
	if (me_cl_id == dev->me_clients_num) {
		err = -ENODEV;
		goto out_err;
	}

	if (length > dev->me_clients[me_cl_id].props.max_msg_length) {
		err = -EINVAL;
		goto out_err;
	}

	err = mei_cl_flow_ctrl_creds(cl);
	if (err < 0)
		goto out_err;

	/* Host buffer is not ready, we queue the request */
	if (err == 0 || !dev->hbuf_is_ready) {
		cb->buf_idx = 0;
		mei_hdr.msg_complete = 0;
		cl->writing_state = MEI_WRITING;
		list_add_tail(&cb->list, &dev->write_list.list);

		mutex_unlock(&dev->device_lock);

		return length;
	}

	dev->hbuf_is_ready = false;

	/* Check for a maximum length */
	if (length > mei_hbuf_max_len(dev)) {
		mei_hdr.length = mei_hbuf_max_len(dev);
		mei_hdr.msg_complete = 0;
	} else {
		mei_hdr.length = length;
		mei_hdr.msg_complete = 1;
	}

	mei_hdr.host_addr = cl->host_client_id;
	mei_hdr.me_addr = cl->me_client_id;
	mei_hdr.reserved = 0;

	if (mei_write_message(dev, &mei_hdr, buf)) {
		err = -EIO;
		goto out_err;
	}

	cl->writing_state = MEI_WRITING;
	cb->buf_idx = mei_hdr.length;

	if (!mei_hdr.msg_complete) {
		list_add_tail(&cb->list, &dev->write_list.list);
	} else {
		if (mei_cl_flow_ctrl_reduce(cl)) {
			err = -EIO;
			goto out_err;
		}

		list_add_tail(&cb->list, &dev->write_waiting_list.list);
	}

	mutex_unlock(&dev->device_lock);

	return mei_hdr.length;

out_err:
	mutex_unlock(&dev->device_lock);
	mei_io_cb_free(cb);

	return err;
}

int __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
{
	struct mei_device *dev;
	struct mei_cl_cb *cb;
	size_t r_length;
	int err;

	if (WARN_ON(!cl || !cl->dev))
		return -ENODEV;

	dev = cl->dev;

	mutex_lock(&dev->device_lock);

	if (!cl->read_cb) {
		err = mei_cl_read_start(cl);
		if (err < 0) {
			mutex_unlock(&dev->device_lock);
			return err;
		}
	}

	if (cl->reading_state != MEI_READ_COMPLETE &&
	    !waitqueue_active(&cl->rx_wait)) {
		mutex_unlock(&dev->device_lock);

		if (wait_event_interruptible(cl->rx_wait,
				(MEI_READ_COMPLETE == cl->reading_state))) {
			if (signal_pending(current))
				return -EINTR;
			return -ERESTARTSYS;
		}

		mutex_lock(&dev->device_lock);
	}

	cb = cl->read_cb;

	if (cl->reading_state != MEI_READ_COMPLETE) {
		r_length = 0;
		goto out;
	}

	r_length = min_t(size_t, length, cb->buf_idx);

	memcpy(buf, cb->response_buffer.data, r_length);

	mei_io_cb_free(cb);
	cl->reading_state = MEI_IDLE;
	cl->read_cb = NULL;

out:
	mutex_unlock(&dev->device_lock);

	return r_length;
}

int mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length)
{
	struct mei_cl *cl = NULL;

	/* TODO: hook between mei_bus_client and mei_cl */

	if (device->ops && device->ops->send)
		return device->ops->send(device, buf, length);

	return __mei_cl_send(cl, buf, length);
}
EXPORT_SYMBOL_GPL(mei_cl_send);

int mei_cl_recv(struct mei_cl_device *device, u8 *buf, size_t length)
{
	struct mei_cl *cl = NULL;

	/* TODO: hook between mei_bus_client and mei_cl */

	if (device->ops && device->ops->recv)
		return device->ops->recv(device, buf, length);

	return __mei_cl_recv(cl, buf, length);
}
EXPORT_SYMBOL_GPL(mei_cl_recv);

static void mei_bus_event_work(struct work_struct *work)
{
	struct mei_cl_device *device;

	device = container_of(work, struct mei_cl_device, event_work);

	if (device->event_cb)
		device->event_cb(device, device->events, device->event_context);

	device->events = 0;

	/* Prepare for the next read */
	mei_cl_read_start(device->cl);
}

int mei_cl_register_event_cb(struct mei_cl_device *device,
			  mei_cl_event_cb_t event_cb, void *context)
{
	if (device->event_cb)
		return -EALREADY;

	device->events = 0;
	device->event_cb = event_cb;
	device->event_context = context;
	INIT_WORK(&device->event_work, mei_bus_event_work);

	mei_cl_read_start(device->cl);

	return 0;
}
EXPORT_SYMBOL_GPL(mei_cl_register_event_cb);
+30 −0
Original line number Diff line number Diff line
@@ -268,6 +268,25 @@ struct mei_cl_device *mei_cl_add_device(struct mei_device *dev,
				  uuid_le uuid, char *name);
void mei_cl_remove_device(struct mei_cl_device *device);

int __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length);
int __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length);

/**
 * struct mei_cl_transport_ops - MEI CL device transport ops
 * This structure allows ME host clients to implement technology
 * specific transport layers.
 *
 * @send: Tx hook for the device. This allows ME host clients to trap
 *	the device driver buffers before actually physically
 *	pushing it to the ME.
 * @recv: Rx hook for the device. This allows ME host clients to trap the
 *	ME buffers before forwarding them to the device driver.
 */
struct mei_cl_transport_ops {
	int (*send)(struct mei_cl_device *device, u8 *buf, size_t length);
	int (*recv)(struct mei_cl_device *device, u8 *buf, size_t length);
};

/**
 * struct mei_cl_device - MEI device handle
 * An mei_cl_device pointer is returned from mei_add_device()
@@ -278,6 +297,10 @@ void mei_cl_remove_device(struct mei_cl_device *device);
 * @dev: linux driver model device pointer
 * @uuid: me client uuid
 * @cl: mei client
 * @ops: ME transport ops
 * @event_cb: Drivers register this callback to get asynchronous ME
 *	events (e.g. Rx buffer pending) notifications.
 * @events: Events bitmask sent to the driver.
 * @priv_data: client private data
 */
struct mei_cl_device {
@@ -285,6 +308,13 @@ struct mei_cl_device {

	struct mei_cl *cl;

	const struct mei_cl_transport_ops *ops;

	struct work_struct event_work;
	mei_cl_event_cb_t event_cb;
	void *event_context;
	unsigned long events;

	void *priv_data;
};

+11 −0
Original line number Diff line number Diff line
@@ -24,4 +24,15 @@ int __mei_cl_driver_register(struct mei_cl_driver *driver,

void mei_cl_driver_unregister(struct mei_cl_driver *driver);

int mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length);
int mei_cl_recv(struct mei_cl_device *device, u8 *buf, size_t length);

typedef void (*mei_cl_event_cb_t)(struct mei_cl_device *device,
			       u32 events, void *context);
int mei_cl_register_event_cb(struct mei_cl_device *device,
			  mei_cl_event_cb_t read_cb, void *context);

#define MEI_CL_EVENT_RX 0
#define MEI_CL_EVENT_TX 1

#endif /* _LINUX_MEI_CL_BUS_H */