[char-misc-next 1/2] mei: bus: add vtag support

From: Tomas Winkler
Date: Mon Nov 16 2020 - 07:57:09 EST


From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>

Add API to support vtag in communication on mei bus.

Add mei_cldev_send_vtag, mei_cldev_recv_vtag and
mei_cldev_recv_nonblock_vtag functions to allow sending a message
with vtag set and to receive vtag of an incoming message.

Cc: Sean Z Huang <sean.z.huang@xxxxxxxxx>
Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
---
drivers/misc/mei/bus-fixup.c | 13 +++--
drivers/misc/mei/bus.c | 101 +++++++++++++++++++++++++++++------
drivers/misc/mei/client.c | 6 ++-
drivers/misc/mei/mei_dev.h | 4 +-
include/linux/mei_cl_bus.h | 6 +++
5 files changed, 104 insertions(+), 26 deletions(-)

diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
index 4e30fa98fe7d..6cc3145bb716 100644
--- a/drivers/misc/mei/bus-fixup.c
+++ b/drivers/misc/mei/bus-fixup.c
@@ -148,7 +148,7 @@ static int mei_osver(struct mei_cl_device *cldev)
os_ver = (struct mei_os_ver *)fwcaps->data;
os_ver->os_type = OSTYPE_LINUX;

- return __mei_cl_send(cldev->cl, buf, size, mode);
+ return __mei_cl_send(cldev->cl, buf, size, 0, mode);
}

#define MKHI_FWVER_BUF_LEN (sizeof(struct mkhi_msg_hdr) + \
@@ -169,7 +169,7 @@ static int mei_fwver(struct mei_cl_device *cldev)
req.hdr.group_id = MKHI_GEN_GROUP_ID;
req.hdr.command = MKHI_GEN_GET_FW_VERSION_CMD;

- ret = __mei_cl_send(cldev->cl, (u8 *)&req, sizeof(req),
+ ret = __mei_cl_send(cldev->cl, (u8 *)&req, sizeof(req), 0,
MEI_CL_IO_TX_BLOCKING);
if (ret < 0) {
dev_err(&cldev->dev, "Could not send ReqFWVersion cmd\n");
@@ -177,7 +177,7 @@ static int mei_fwver(struct mei_cl_device *cldev)
}

ret = 0;
- bytes_recv = __mei_cl_recv(cldev->cl, buf, sizeof(buf), 0,
+ bytes_recv = __mei_cl_recv(cldev->cl, buf, sizeof(buf), NULL, 0,
MKHI_RCV_TIMEOUT);
if (bytes_recv < 0 || (size_t)bytes_recv < MKHI_FWVER_LEN(1)) {
/*
@@ -324,13 +324,15 @@ static int mei_nfc_if_version(struct mei_cl *cl,
};
struct mei_nfc_reply *reply = NULL;
size_t if_version_length;
+ u8 vtag;
int bytes_recv, ret;

bus = cl->dev;

WARN_ON(mutex_is_locked(&bus->device_lock));

- ret = __mei_cl_send(cl, (u8 *)&cmd, sizeof(cmd), MEI_CL_IO_TX_BLOCKING);
+ ret = __mei_cl_send(cl, (u8 *)&cmd, sizeof(cmd), 0,
+ MEI_CL_IO_TX_BLOCKING);
if (ret < 0) {
dev_err(bus->dev, "Could not send IF version cmd\n");
return ret;
@@ -344,7 +346,8 @@ static int mei_nfc_if_version(struct mei_cl *cl,
return -ENOMEM;

ret = 0;
- bytes_recv = __mei_cl_recv(cl, (u8 *)reply, if_version_length, 0, 0);
+ bytes_recv = __mei_cl_recv(cl, (u8 *)reply, if_version_length, &vtag,
+ 0, 0);
if (bytes_recv < 0 || (size_t)bytes_recv < if_version_length) {
dev_err(bus->dev, "Could not read IF version\n");
ret = -EIO;
diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 7fe48baa103a..2907db260fba 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -26,11 +26,12 @@
* @cl: host client
* @buf: buffer to send
* @length: buffer length
+ * @vtag: virtual tag
* @mode: sending mode
*
* Return: written size bytes or < 0 on error
*/
-ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
+ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length, u8 vtag,
unsigned int mode)
{
struct mei_device *bus;
@@ -86,6 +87,7 @@ ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
rets = -ENOMEM;
goto out;
}
+ cb->vtag = vtag;

cb->internal = !!(mode & MEI_CL_IO_TX_INTERNAL);
cb->blocking = !!(mode & MEI_CL_IO_TX_BLOCKING);
@@ -106,11 +108,12 @@ ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
* @buf: buffer to receive
* @length: buffer length
* @mode: io mode
+ * @vtag: virtual tag
* @timeout: recv timeout, 0 for infinite timeout
*
* Return: read size in bytes of < 0 on error
*/
-ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
+ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length, u8 *vtag,
unsigned int mode, unsigned long timeout)
{
struct mei_device *bus;
@@ -196,6 +199,8 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
r_length = min_t(size_t, length, cb->buf_idx);
memcpy(buf, cb->buf.data, r_length);
rets = r_length;
+ if (vtag)
+ *vtag = cb->vtag;

free:
mei_cl_del_rd_completed(cl, cb);
@@ -206,40 +211,87 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
}

/**
- * mei_cldev_send - me device send (write)
+ * mei_cldev_send_vtag - me device send with vtag (write)
*
* @cldev: me client device
* @buf: buffer to send
* @length: buffer length
+ * @vtag: virtual tag
*
- * Return: written size in bytes or < 0 on error
+ * Return:
+ * * written size in bytes
+ * * < 0 on error
*/
-ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
+
+ssize_t mei_cldev_send_vtag(struct mei_cl_device *cldev, u8 *buf, size_t length,
+ u8 vtag)
{
struct mei_cl *cl = cldev->cl;

- return __mei_cl_send(cl, buf, length, MEI_CL_IO_TX_BLOCKING);
+ return __mei_cl_send(cl, buf, length, vtag, MEI_CL_IO_TX_BLOCKING);
}
-EXPORT_SYMBOL_GPL(mei_cldev_send);
+EXPORT_SYMBOL_GPL(mei_cldev_send_vtag);

/**
- * mei_cldev_recv_nonblock - non block client receive (read)
+ * mei_cldev_recv_vtag - client receive with vtag (read)
*
* @cldev: me client device
* @buf: buffer to receive
* @length: buffer length
+ * @vtag: virtual tag
*
- * Return: read size in bytes of < 0 on error
- * -EAGAIN if function will block.
+ * Return:
+ * * read size in bytes
+ * * < 0 on error
*/
-ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
- size_t length)
+
+ssize_t mei_cldev_recv_vtag(struct mei_cl_device *cldev, u8 *buf, size_t length,
+ u8 *vtag)
{
struct mei_cl *cl = cldev->cl;

- return __mei_cl_recv(cl, buf, length, MEI_CL_IO_RX_NONBLOCK, 0);
+ return __mei_cl_recv(cl, buf, length, vtag, 0, 0);
}
-EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
+EXPORT_SYMBOL_GPL(mei_cldev_recv_vtag);
+
+/**
+ * mei_cldev_recv_nonblock_vtag - non block client receive with vtag (read)
+ *
+ * @cldev: me client device
+ * @buf: buffer to receive
+ * @length: buffer length
+ * @vtag: virtual tag
+ *
+ * Return:
+ * * read size in bytes
+ * * -EAGAIN if function will block.
+ * * < 0 on other error
+ */
+ssize_t mei_cldev_recv_nonblock_vtag(struct mei_cl_device *cldev, u8 *buf,
+ size_t length, u8 *vtag)
+{
+ struct mei_cl *cl = cldev->cl;
+
+ return __mei_cl_recv(cl, buf, length, vtag, MEI_CL_IO_RX_NONBLOCK, 0);
+}
+EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock_vtag);
+
+/**
+ * mei_cldev_send - me device send (write)
+ *
+ * @cldev: me client device
+ * @buf: buffer to send
+ * @length: buffer length
+ *
+ * Return:
+ * * written size in bytes
+ * * < 0 on error
+ */
+ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
+{
+ return mei_cldev_send_vtag(cldev, buf, length, 0);
+}
+EXPORT_SYMBOL_GPL(mei_cldev_send);

/**
* mei_cldev_recv - client receive (read)
@@ -252,12 +304,27 @@ EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
*/
ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
{
- struct mei_cl *cl = cldev->cl;
-
- return __mei_cl_recv(cl, buf, length, 0, 0);
+ return mei_cldev_recv_vtag(cldev, buf, length, NULL);
}
EXPORT_SYMBOL_GPL(mei_cldev_recv);

+/**
+ * mei_cldev_recv_nonblock - non block client receive (read)
+ *
+ * @cldev: me client device
+ * @buf: buffer to receive
+ * @length: buffer length
+ *
+ * Return: read size in bytes of < 0 on error
+ * -EAGAIN if function will block.
+ */
+ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
+ size_t length)
+{
+ return mei_cldev_recv_nonblock_vtag(cldev, buf, length, NULL);
+}
+EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
+
/**
* mei_cl_bus_rx_work - dispatch rx event for a bus device
*
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index d5c3f7d54634..a56d41321f32 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -1306,7 +1306,7 @@ struct mei_cl_vtag *mei_cl_vtag_alloc(struct file *fp, u8 vtag)
* mei_cl_fp_by_vtag - obtain the file pointer by vtag
*
* @cl: host client
- * @vtag: vm tag
+ * @vtag: virtual tag
*
* Return:
* * A file pointer - on success
@@ -1317,7 +1317,9 @@ const struct file *mei_cl_fp_by_vtag(const struct mei_cl *cl, u8 vtag)
struct mei_cl_vtag *vtag_l;

list_for_each_entry(vtag_l, &cl->vtag_map, list)
- if (vtag_l->vtag == vtag)
+ /* The client on bus has one fixed fp */
+ if ((cl->cldev && mei_cldev_enabled(cl->cldev)) ||
+ vtag_l->vtag == vtag)
return vtag_l->fp;

return ERR_PTR(-ENOENT);
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 2f4cc1a8aae8..8c395bfdf6f3 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -340,9 +340,9 @@ struct mei_hw_ops {
/* MEI bus API*/
void mei_cl_bus_rescan_work(struct work_struct *work);
void mei_cl_bus_dev_fixup(struct mei_cl_device *dev);
-ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
+ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length, u8 vtag,
unsigned int mode);
-ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
+ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length, u8 *vtag,
unsigned int mode, unsigned long timeout);
bool mei_cl_bus_rx_event(struct mei_cl *cl);
bool mei_cl_bus_notify_event(struct mei_cl *cl);
diff --git a/include/linux/mei_cl_bus.h b/include/linux/mei_cl_bus.h
index 52aa4821093a..959ad7d850b4 100644
--- a/include/linux/mei_cl_bus.h
+++ b/include/linux/mei_cl_bus.h
@@ -95,6 +95,12 @@ ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length);
ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length);
ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
size_t length);
+ssize_t mei_cldev_send_vtag(struct mei_cl_device *cldev, u8 *buf, size_t length,
+ u8 vtag);
+ssize_t mei_cldev_recv_vtag(struct mei_cl_device *cldev, u8 *buf, size_t length,
+ u8 *vtag);
+ssize_t mei_cldev_recv_nonblock_vtag(struct mei_cl_device *cldev, u8 *buf,
+ size_t length, u8 *vtag);

int mei_cldev_register_rx_cb(struct mei_cl_device *cldev, mei_cldev_cb_t rx_cb);
int mei_cldev_register_notif_cb(struct mei_cl_device *cldev,
--
2.26.2