[char-misc-next 21/27] mei: fill file pointer in read cb for fixed address client

From: Tomas Winkler
Date: Sun Feb 07 2016 - 16:37:30 EST


From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>

The read callback created from a flow control request for
a fixed address client have NULL in the file pointer.
Fill the file pointer using a data from a write callback.

This allows us to drop workaround introduced in:
commit eeabfcf5a92a ("mei: connection to fixed address clients from user-space")

Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
---
drivers/misc/mei/client.c | 11 +-
drivers/misc/mei/main.c | 5 -
drivers/misc/mei/wd.c | 391 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 397 insertions(+), 10 deletions(-)
create mode 100644 drivers/misc/mei/wd.c

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 3a9c656f1425..a27ae2deecb4 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -1173,11 +1173,12 @@ err:
/**
* mei_cl_flow_ctrl_creds - checks flow_control credits for cl.
*
- * @cl: private data of the file object
+ * @cl: host client
+ * @fp: the file pointer associated with the pointer
*
* Return: 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
*/
-static int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
+static int mei_cl_flow_ctrl_creds(struct mei_cl *cl, const struct file *fp)
{
int rets;

@@ -1188,7 +1189,7 @@ static int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
return 1;

if (mei_cl_is_fixed_address(cl)) {
- rets = mei_cl_read_start(cl, mei_cl_mtu(cl), NULL);
+ rets = mei_cl_read_start(cl, mei_cl_mtu(cl), fp);
if (rets && rets != -EBUSY)
return rets;
return 1;
@@ -1568,7 +1569,7 @@ int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,

first_chunk = cb->buf_idx == 0;

- rets = first_chunk ? mei_cl_flow_ctrl_creds(cl) : 1;
+ rets = first_chunk ? mei_cl_flow_ctrl_creds(cl, cb->fp) : 1;
if (rets < 0)
return rets;

@@ -1674,7 +1675,7 @@ int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
mei_hdr.msg_complete = 0;
mei_hdr.internal = cb->internal;

- rets = mei_cl_flow_ctrl_creds(cl);
+ rets = mei_cl_flow_ctrl_creds(cl, cb->fp);
if (rets < 0)
goto err;

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index ba9790ead256..c8a8d4df84e4 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -209,11 +209,6 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,

cb = mei_cl_read_cb(cl, file);
if (!cb) {
- if (mei_cl_is_fixed_address(cl) && dev->allow_fixed_address) {
- cb = mei_cl_read_cb(cl, NULL);
- if (cb)
- goto copy_buffer;
- }
rets = 0;
goto out;
}
diff --git a/drivers/misc/mei/wd.c b/drivers/misc/mei/wd.c
new file mode 100644
index 000000000000..7d9b4ee42f65
--- /dev/null
+++ b/drivers/misc/mei/wd.c
@@ -0,0 +1,391 @@
+/*
+ *
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ * Copyright (c) 2003-2012, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+#include <linux/sched.h>
+#include <linux/watchdog.h>
+
+#include <linux/mei.h>
+
+#include "mei_dev.h"
+#include "hbm.h"
+#include "client.h"
+
+static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
+static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
+
+/*
+ * AMT Watchdog Device
+ */
+#define INTEL_AMT_WATCHDOG_ID "INTCAMT"
+
+/* UUIDs for AMT F/W clients */
+const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
+ 0x9D, 0xA9, 0x15, 0x14, 0xCB,
+ 0x32, 0xAB);
+
+static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
+{
+ dev_dbg(dev->dev, "wd: set timeout=%d.\n", timeout);
+ memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE);
+ memcpy(dev->wd_data + MEI_WD_HDR_SIZE, &timeout, sizeof(u16));
+}
+
+/**
+ * mei_wd_host_init - connect to the watchdog client
+ *
+ * @dev: the device structure
+ * @me_cl: me client
+ *
+ * Return: -ENOTTY if wd client cannot be found
+ * -EIO if write has failed
+ * 0 on success
+ */
+int mei_wd_host_init(struct mei_device *dev, struct mei_me_client *me_cl)
+{
+ struct mei_cl *cl = &dev->wd_cl;
+ int ret;
+
+ mei_cl_init(cl, dev);
+
+ dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
+ dev->wd_state = MEI_WD_IDLE;
+
+ ret = mei_cl_link(cl, MEI_WD_HOST_CLIENT_ID);
+ if (ret < 0) {
+ dev_info(dev->dev, "wd: failed link client\n");
+ return ret;
+ }
+
+ ret = mei_cl_connect(cl, me_cl, NULL);
+ if (ret) {
+ dev_err(dev->dev, "wd: failed to connect = %d\n", ret);
+ mei_cl_unlink(cl);
+ return ret;
+ }
+
+ ret = mei_watchdog_register(dev);
+ if (ret) {
+ mei_cl_disconnect(cl);
+ mei_cl_unlink(cl);
+ }
+ return ret;
+}
+
+/**
+ * mei_wd_send - sends watch dog message to fw.
+ *
+ * @dev: the device structure
+ *
+ * Return: 0 if success,
+ * -EIO when message send fails
+ * -EINVAL when invalid message is to be sent
+ * -ENODEV on flow control failure
+ */
+int mei_wd_send(struct mei_device *dev)
+{
+ struct mei_cl *cl = &dev->wd_cl;
+ struct mei_msg_hdr hdr;
+ int ret;
+
+ hdr.host_addr = cl->host_client_id;
+ hdr.me_addr = mei_cl_me_id(cl);
+ hdr.msg_complete = 1;
+ hdr.reserved = 0;
+ hdr.internal = 0;
+
+ if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE))
+ hdr.length = MEI_WD_START_MSG_SIZE;
+ else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_HDR_SIZE))
+ hdr.length = MEI_WD_STOP_MSG_SIZE;
+ else {
+ dev_err(dev->dev, "wd: invalid message is to be sent, aborting\n");
+ return -EINVAL;
+ }
+
+ ret = mei_write_message(dev, &hdr, dev->wd_data);
+ if (ret) {
+ dev_err(dev->dev, "wd: write message failed\n");
+ return ret;
+ }
+
+ ret = mei_cl_flow_ctrl_reduce(cl);
+ if (ret) {
+ dev_err(dev->dev, "wd: flow_ctrl_reduce failed.\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * mei_wd_stop - sends watchdog stop message to fw.
+ *
+ * @dev: the device structure
+ *
+ * Return: 0 if success
+ * on error:
+ * -EIO when message send fails
+ * -EINVAL when invalid message is to be sent
+ * -ETIME on message timeout
+ */
+int mei_wd_stop(struct mei_device *dev)
+{
+ struct mei_cl *cl = &dev->wd_cl;
+ int ret;
+
+ if (!mei_cl_is_connected(cl) ||
+ dev->wd_state != MEI_WD_RUNNING)
+ return 0;
+
+ memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_STOP_MSG_SIZE);
+
+ dev->wd_state = MEI_WD_STOPPING;
+
+ ret = mei_cl_flow_ctrl_creds(cl, NULL);
+ if (ret < 0)
+ goto err;
+
+ if (ret && mei_hbuf_acquire(dev)) {
+ ret = mei_wd_send(dev);
+ if (ret)
+ goto err;
+ dev->wd_pending = false;
+ } else {
+ dev->wd_pending = true;
+ }
+
+ mutex_unlock(&dev->device_lock);
+
+ ret = wait_event_timeout(dev->wait_stop_wd,
+ dev->wd_state == MEI_WD_IDLE,
+ msecs_to_jiffies(MEI_WD_STOP_TIMEOUT));
+ mutex_lock(&dev->device_lock);
+ if (dev->wd_state != MEI_WD_IDLE) {
+ /* timeout */
+ ret = -ETIME;
+ dev_warn(dev->dev, "wd: stop failed to complete ret=%d\n", ret);
+ goto err;
+ }
+ dev_dbg(dev->dev, "wd: stop completed after %u msec\n",
+ MEI_WD_STOP_TIMEOUT - jiffies_to_msecs(ret));
+ return 0;
+err:
+ return ret;
+}
+
+/**
+ * mei_wd_ops_start - wd start command from the watchdog core.
+ *
+ * @wd_dev: watchdog device struct
+ *
+ * Return: 0 if success, negative errno code for failure
+ */
+static int mei_wd_ops_start(struct watchdog_device *wd_dev)
+{
+ struct mei_device *dev;
+ struct mei_cl *cl;
+ int err = -ENODEV;
+
+ dev = watchdog_get_drvdata(wd_dev);
+ if (!dev)
+ return -ENODEV;
+
+ cl = &dev->wd_cl;
+
+ mutex_lock(&dev->device_lock);
+
+ if (dev->dev_state != MEI_DEV_ENABLED) {
+ dev_dbg(dev->dev, "wd: dev_state != MEI_DEV_ENABLED dev_state = %s\n",
+ mei_dev_state_str(dev->dev_state));
+ goto end_unlock;
+ }
+
+ if (!mei_cl_is_connected(cl)) {
+ cl_dbg(dev, cl, "MEI Driver is not connected to Watchdog Client\n");
+ goto end_unlock;
+ }
+
+ mei_wd_set_start_timeout(dev, dev->wd_timeout);
+
+ err = 0;
+end_unlock:
+ mutex_unlock(&dev->device_lock);
+ return err;
+}
+
+/**
+ * mei_wd_ops_stop - wd stop command from the watchdog core.
+ *
+ * @wd_dev: watchdog device struct
+ *
+ * Return: 0 if success, negative errno code for failure
+ */
+static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
+{
+ struct mei_device *dev;
+
+ dev = watchdog_get_drvdata(wd_dev);
+ if (!dev)
+ return -ENODEV;
+
+ mutex_lock(&dev->device_lock);
+ mei_wd_stop(dev);
+ mutex_unlock(&dev->device_lock);
+
+ return 0;
+}
+
+/**
+ * mei_wd_ops_ping - wd ping command from the watchdog core.
+ *
+ * @wd_dev: watchdog device struct
+ *
+ * Return: 0 if success, negative errno code for failure
+ */
+static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
+{
+ struct mei_device *dev;
+ struct mei_cl *cl;
+ int ret;
+
+ dev = watchdog_get_drvdata(wd_dev);
+ if (!dev)
+ return -ENODEV;
+
+ cl = &dev->wd_cl;
+
+ mutex_lock(&dev->device_lock);
+
+ if (!mei_cl_is_connected(cl)) {
+ cl_err(dev, cl, "wd: not connected.\n");
+ ret = -ENODEV;
+ goto end;
+ }
+
+ dev->wd_state = MEI_WD_RUNNING;
+
+ ret = mei_cl_flow_ctrl_creds(cl, NULL);
+ if (ret < 0)
+ goto end;
+
+ /* Check if we can send the ping to HW*/
+ if (ret && mei_hbuf_acquire(dev)) {
+ dev_dbg(dev->dev, "wd: sending ping\n");
+
+ ret = mei_wd_send(dev);
+ if (ret)
+ goto end;
+ dev->wd_pending = false;
+ } else {
+ dev->wd_pending = true;
+ }
+
+end:
+ mutex_unlock(&dev->device_lock);
+ return ret;
+}
+
+/**
+ * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
+ *
+ * @wd_dev: watchdog device struct
+ * @timeout: timeout value to set
+ *
+ * Return: 0 if success, negative errno code for failure
+ */
+static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev,
+ unsigned int timeout)
+{
+ struct mei_device *dev;
+
+ dev = watchdog_get_drvdata(wd_dev);
+ if (!dev)
+ return -ENODEV;
+
+ /* Check Timeout value */
+ if (timeout < MEI_WD_MIN_TIMEOUT || timeout > MEI_WD_MAX_TIMEOUT)
+ return -EINVAL;
+
+ mutex_lock(&dev->device_lock);
+
+ dev->wd_timeout = timeout;
+ wd_dev->timeout = timeout;
+ mei_wd_set_start_timeout(dev, dev->wd_timeout);
+
+ mutex_unlock(&dev->device_lock);
+
+ return 0;
+}
+
+/*
+ * Watchdog Device structs
+ */
+static const struct watchdog_ops wd_ops = {
+ .owner = THIS_MODULE,
+ .start = mei_wd_ops_start,
+ .stop = mei_wd_ops_stop,
+ .ping = mei_wd_ops_ping,
+ .set_timeout = mei_wd_ops_set_timeout,
+};
+static const struct watchdog_info wd_info = {
+ .identity = INTEL_AMT_WATCHDOG_ID,
+ .options = WDIOF_KEEPALIVEPING |
+ WDIOF_SETTIMEOUT |
+ WDIOF_ALARMONLY,
+};
+
+static struct watchdog_device amt_wd_dev = {
+ .info = &wd_info,
+ .ops = &wd_ops,
+ .timeout = MEI_WD_DEFAULT_TIMEOUT,
+ .min_timeout = MEI_WD_MIN_TIMEOUT,
+ .max_timeout = MEI_WD_MAX_TIMEOUT,
+};
+
+
+int mei_watchdog_register(struct mei_device *dev)
+{
+
+ int ret;
+
+ amt_wd_dev.parent = dev->dev;
+ /* unlock to perserve correct locking order */
+ mutex_unlock(&dev->device_lock);
+ ret = watchdog_register_device(&amt_wd_dev);
+ mutex_lock(&dev->device_lock);
+ if (ret) {
+ dev_err(dev->dev, "wd: unable to register watchdog device = %d.\n",
+ ret);
+ return ret;
+ }
+
+ dev_dbg(dev->dev, "wd: successfully register watchdog interface.\n");
+ watchdog_set_drvdata(&amt_wd_dev, dev);
+ return 0;
+}
+
+void mei_watchdog_unregister(struct mei_device *dev)
+{
+ if (watchdog_get_drvdata(&amt_wd_dev) == NULL)
+ return;
+
+ watchdog_set_drvdata(&amt_wd_dev, NULL);
+ watchdog_unregister_device(&amt_wd_dev);
+}
+
--
2.4.3