mei: add mei_hbuf_acquire wrapper

A client has to acquire host buffer
before writing, we add lock like wrapper
to replace the code snippet

if (dev->hbuf_is_ready)
        dev->hbuf_is_ready = false;

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

7 files changed, 57 insertions, 47 deletions

diff --git a/drivers/misc/mei/amthif.c b/drivers/misc/mei/amthif.c
index 61275e6e839c..e7ba8801d2b4 100644
--- a/drivers/misc/mei/amthif.c
+++ b/drivers/misc/mei/amthif.c
@@ -296,9 +296,8 @@ static int mei_amthif_send_cmd(struct mei_device *dev, struct mei_cl_cb *cb)
         if (ret < 0)
                 return ret;
 
-        if (ret && dev->hbuf_is_ready) {
+        if (ret && mei_hbuf_acquire(dev)) {
                 ret = 0;
-                dev->hbuf_is_ready = false;
                 if (cb->request_buffer.size > mei_hbuf_max_len(dev)) {
                         mei_hdr.length = mei_hbuf_max_len(dev);
                         mei_hdr.msg_complete = 0;
@@ -330,10 +329,6 @@ static int mei_amthif_send_cmd(struct mei_device *dev, struct mei_cl_cb *cb)
                         list_add_tail(&cb->list, &dev->write_list.list);
                 }
         } else {
-                if (!dev->hbuf_is_ready)
-                        dev_dbg(&dev->pdev->dev, "host buffer is not empty");
-
-                dev_dbg(&dev->pdev->dev, "No flow control credentials, so add iamthif cb to write list.\n");
                 list_add_tail(&cb->list, &dev->write_list.list);
         }
         return 0;
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 2df0efab00a2..083179b75297 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -371,6 +371,23 @@ void mei_host_client_init(struct work_struct *work)
         mutex_unlock(&dev->device_lock);
 }
 
+/**
+ * mei_hbuf_acquire: try to acquire host buffer
+ *
+ * @dev: the device structure
+ * returns true if host buffer was acquired
+ */
+bool mei_hbuf_acquire(struct mei_device *dev)
+{
+        if (!dev->hbuf_is_ready) {
+                dev_dbg(&dev->pdev->dev, "hbuf is not ready\n");
+                return false;
+        }
+
+        dev->hbuf_is_ready = false;
+
+        return true;
+}
 
 /**
  * mei_cl_disconnect - disconnect host client from the me one
@@ -402,8 +419,7 @@ int mei_cl_disconnect(struct mei_cl *cl)
                 return -ENOMEM;
 
         cb->fop_type = MEI_FOP_CLOSE;
-        if (dev->hbuf_is_ready) {
-                dev->hbuf_is_ready = false;
+        if (mei_hbuf_acquire(dev)) {
                 if (mei_hbm_cl_disconnect_req(dev, cl)) {
                         rets = -ENODEV;
                         cl_err(dev, cl, "failed to disconnect.\n");
@@ -503,9 +519,8 @@ int mei_cl_connect(struct mei_cl *cl, struct file *file)
 
         cb->fop_type = MEI_FOP_CONNECT;
 
-        if (dev->hbuf_is_ready && !mei_cl_is_other_connecting(cl)) {
-                dev->hbuf_is_ready = false;
-
+        /* run hbuf acquire last so we don't have to undo */
+        if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
                 if (mei_hbm_cl_connect_req(dev, cl)) {
                         rets = -ENODEV;
                         goto out;
@@ -663,8 +678,7 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length)
                 goto err;
 
         cb->fop_type = MEI_FOP_READ;
-        if (dev->hbuf_is_ready) {
-                dev->hbuf_is_ready = false;
+        if (mei_hbuf_acquire(dev)) {
                 if (mei_hbm_cl_flow_control_req(dev, cl)) {
                         cl_err(dev, cl, "flow control send failed\n");
                         rets = -ENODEV;
@@ -799,21 +813,29 @@ int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
 
 
         cb->fop_type = MEI_FOP_WRITE;
+        cb->buf_idx = 0;
+        cl->writing_state = MEI_IDLE;
+
+        mei_hdr.host_addr = cl->host_client_id;
+        mei_hdr.me_addr = cl->me_client_id;
+        mei_hdr.reserved = 0;
+        mei_hdr.msg_complete = 0;
+        mei_hdr.internal = cb->internal;
 
         rets = mei_cl_flow_ctrl_creds(cl);
         if (rets < 0)
                 goto err;
 
-        /* Host buffer is not ready, we queue the request */
-        if (rets == 0 || !dev->hbuf_is_ready) {
-                cb->buf_idx = 0;
-                /* unseting complete will enqueue the cb for write */
-                mei_hdr.msg_complete = 0;
+        if (rets == 0) {
+                cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
+                rets = buf->size;
+                goto out;
+        }
+        if (!mei_hbuf_acquire(dev)) {
+                cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
                 rets = buf->size;
                 goto out;
         }
-
-        dev->hbuf_is_ready = false;
 
         /* Check for a maximum length */
         if (buf->size > mei_hbuf_max_len(dev)) {
@@ -824,12 +846,6 @@ int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
                 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;
-        mei_hdr.internal = cb->internal;
-
-
         rets = mei_write_message(dev, &mei_hdr, buf->data);
         if (rets)
                 goto err;
diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 847c9e5746cb..b0c42d6182a6 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -513,6 +513,8 @@ irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
                 }
         }
 
+        dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
+
         rets = mei_irq_write_handler(dev, &complete_list);
 
         dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
diff --git a/drivers/misc/mei/hw-txe.c b/drivers/misc/mei/hw-txe.c
index 49a5ed376969..8f5e4be9ebc2 100644
--- a/drivers/misc/mei/hw-txe.c
+++ b/drivers/misc/mei/hw-txe.c
@@ -605,7 +605,6 @@ static int mei_txe_write(struct mei_device *dev,
                 mei_txe_input_payload_write(dev, i + 1, reg);
         }
 
-        dev->hbuf_is_ready = false;
         /* Set Input-Doorbell */
         mei_txe_input_doorbell_set(hw);
 
@@ -983,20 +982,16 @@ irqreturn_t mei_txe_irq_thread_handler(int irq, void *dev_id)
                 dev->hbuf_is_ready = true;
 
         if (hw->aliveness && dev->hbuf_is_ready) {
-                /* if SeC did not complete reading the written data by host */
-                if (!mei_txe_is_input_ready(dev)) {
-                        dev_dbg(&dev->pdev->dev, "got Input Ready Int, but SEC_IPC_INPUT_STATUS_RDY is 0.\n");
-                        goto end;
-                }
 
+                /* get the real register value */
+                dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
                 rets = mei_irq_write_handler(dev, &complete_list);
-                if (rets)
-                        dev_err(&dev->pdev->dev,
-                                "mei_irq_write_handler ret = %d.\n", rets);
+                if (rets && rets != -EMSGSIZE)
+                        dev_err(&dev->pdev->dev, "mei_irq_write_handler ret = %d.\n",
+                                rets);
+                dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
         }
 
-
-
         mei_irq_compl_handler(dev, &complete_list);
 
 end:
diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 6c4597e9b997..aed03efa72f4 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -446,10 +446,10 @@ int mei_irq_write_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list)
         s32 slots;
         int ret;
 
-        if (!mei_hbuf_is_ready(dev)) {
-                dev_dbg(&dev->pdev->dev, "host buffer is not empty.\n");
+
+        if (!mei_hbuf_acquire(dev))
                 return 0;
-        }
+
         slots = mei_hbuf_empty_slots(dev);
         if (slots <= 0)
                 return -EMSGSIZE;
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 030b29e1c92e..52499bc5a068 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -630,6 +630,8 @@ static inline int mei_count_full_read_slots(struct mei_device *dev)
         return dev->ops->rdbuf_full_slots(dev);
 }
 
+bool mei_hbuf_acquire(struct mei_device *dev);
+
 #if IS_ENABLED(CONFIG_DEBUG_FS)
 int mei_dbgfs_register(struct mei_device *dev, const char *name);
 void mei_dbgfs_deregister(struct mei_device *dev);
diff --git a/drivers/misc/mei/wd.c b/drivers/misc/mei/wd.c
index 8c302829a194..afe976a18586 100644
--- a/drivers/misc/mei/wd.c
+++ b/drivers/misc/mei/wd.c
@@ -158,9 +158,8 @@ int mei_wd_stop(struct mei_device *dev)
         if (ret < 0)
                 goto out;
 
-        if (ret && dev->hbuf_is_ready) {
+        if (ret && mei_hbuf_acquire(dev)) {
                 ret = 0;
-                dev->hbuf_is_ready = false;
 
                 if (!mei_wd_send(dev)) {
                         ret = mei_cl_flow_ctrl_reduce(&dev->wd_cl);
@@ -265,8 +264,8 @@ static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
  */
 static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
 {
-        int ret = 0;
         struct mei_device *dev;
+        int ret;
 
         dev = watchdog_get_drvdata(wd_dev);
         if (!dev)
@@ -282,10 +281,12 @@ static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
 
         dev->wd_state = MEI_WD_RUNNING;
 
+        ret = mei_cl_flow_ctrl_creds(&dev->wd_cl);
+        if (ret < 0)
+                goto end;
         /* Check if we can send the ping to HW*/
-        if (dev->hbuf_is_ready && mei_cl_flow_ctrl_creds(&dev->wd_cl) > 0) {
+        if (ret && mei_hbuf_acquire(dev)) {
 
-                dev->hbuf_is_ready = false;
                 dev_dbg(&dev->pdev->dev, "wd: sending ping\n");
 
                 if (mei_wd_send(dev)) {
@@ -295,8 +296,7 @@ static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
                 }
 
                 if (mei_cl_flow_ctrl_reduce(&dev->wd_cl)) {
-                        dev_err(&dev->pdev->dev,
-                                "wd: mei_cl_flow_ctrl_reduce() failed.\n");
+                        dev_err(&dev->pdev->dev, "wd: mei_cl_flow_ctrl_reduce() failed.\n");
                         ret = -EIO;
                         goto end;
                 }