mei: use structured buffer for extra write buffer

The structure of the message is static so we don't have
to use and cast the buffer. We can also drop extra_write_index
variable as this information can be extracted directly
from the message header

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

3 files changed, 22 insertions, 27 deletions

diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index 02784af1d1a1..49600d6e3726 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -288,7 +288,7 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
                 mei_me_cl_unlink(dev, &dev->iamthif_cl);
 
                 mei_amthif_reset_params(dev);
-                dev->extra_write_index = 0;
+                memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
         }
 
         dev->me_clients_num = 0;
diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 14becc0d5563..92246465ea11 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -446,15 +446,14 @@ static void mei_client_disconnect_request(struct mei_device *dev,
                                 dev->iamthif_timer = 0;
 
                         /* prepare disconnect response */
-                        (void)mei_hbm_hdr(&dev->ext_msg_buf[0], len);
+                        (void)mei_hbm_hdr((u32 *)&dev->wr_ext_msg.hdr, len);
                         disconnect_res =
                                 (struct hbm_client_connect_response *)
-                                &dev->ext_msg_buf[1];
+                                &dev->wr_ext_msg.data;
                         disconnect_res->hbm_cmd = CLIENT_DISCONNECT_RES_CMD;
                         disconnect_res->host_addr = pos->host_client_id;
                         disconnect_res->me_addr = pos->me_client_id;
                         disconnect_res->status = 0;
-                        dev->extra_write_index = 2;
                         break;
                 }
         }
@@ -643,16 +642,13 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
         {
                 /* prepare stop request: sent in next interrupt event */
 
-                u32 *buf = dev->ext_msg_buf;
                 const size_t len = sizeof(struct hbm_host_stop_request);
 
-                mei_hdr = mei_hbm_hdr(&buf[0], len);
-                stop_req = (struct hbm_host_stop_request *)&buf[1];
+                mei_hdr = mei_hbm_hdr((u32 *)&dev->wr_ext_msg.hdr, len);
+                stop_req = (struct hbm_host_stop_request *)&dev->wr_ext_msg.data;
                 memset(stop_req, 0, len);
                 stop_req->hbm_cmd = HOST_STOP_REQ_CMD;
                 stop_req->reason = DRIVER_STOP_REQUEST;
-
-                dev->extra_write_index = 2;
                 break;
         }
         default:
@@ -988,15 +984,11 @@ static int mei_irq_thread_write_handler(struct mei_cl_cb *cmpl_list,
                 wake_up_interruptible(&dev->wait_stop_wd);
         }
 
-        if (dev->extra_write_index) {
-                dev_dbg(&dev->pdev->dev, "extra_write_index =%d.\n",
-                                dev->extra_write_index);
-                mei_write_message(dev,
-                                (struct mei_msg_hdr *) &dev->ext_msg_buf[0],
-                                (unsigned char *) &dev->ext_msg_buf[1],
-                                (dev->extra_write_index - 1) * sizeof(u32));
-                *slots -= dev->extra_write_index;
-                dev->extra_write_index = 0;
+        if (dev->wr_ext_msg.hdr.length) {
+                mei_write_message(dev, &dev->wr_ext_msg.hdr,
+                        dev->wr_ext_msg.data, dev->wr_ext_msg.hdr.length);
+                *slots -= mei_data2slots(dev->wr_ext_msg.hdr.length);
+                dev->wr_ext_msg.hdr.length = 0;
         }
         if (dev->dev_state == MEI_DEV_ENABLED) {
                 if (dev->wd_pending &&
@@ -1263,11 +1255,11 @@ irqreturn_t mei_interrupt_thread_handler(int irq, void *dev_id)
         }
         /* check slots available for reading */
         slots = mei_count_full_read_slots(dev);
-        dev_dbg(&dev->pdev->dev, "slots =%08x  extra_write_index =%08x.\n",
-                slots, dev->extra_write_index);
-        while (slots > 0 && !dev->extra_write_index) {
-                dev_dbg(&dev->pdev->dev, "slots =%08x  extra_write_index =%08x.\n",
-                                slots, dev->extra_write_index);
+        while (slots > 0) {
+                /* we have urgent data to send so break the read */
+                if (dev->wr_ext_msg.hdr.length)
+                        break;
+                dev_dbg(&dev->pdev->dev, "slots =%08x\n", slots);
                 dev_dbg(&dev->pdev->dev, "call mei_irq_thread_read_handler.\n");
                 rets = mei_irq_thread_read_handler(&complete_list, dev, &slots);
                 if (rets)
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index e511b84ff4ce..2a38e95e5de0 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -192,8 +192,9 @@ struct mei_cl {
 };
 
 /**
- * struct mei_deive -  MEI private device struct
+ * struct mei_device -  MEI private device struct
  * @hbuf_depth - depth of host(write) buffer
+ * @wr_ext_msg - buffer for hbm control responses (set in read cycle)
  */
 struct mei_device {
         struct pci_dev *pdev;   /* pointer to pci device struct */
@@ -244,11 +245,13 @@ struct mei_device {
         u16 init_clients_timer;
         bool need_reset;
 
-        u32 extra_write_index;
         unsigned char rd_msg_buf[MEI_RD_MSG_BUF_SIZE];  /* control messages */
-        u32 wr_msg_buf[128];    /* used for control messages */
-        u32 ext_msg_buf[8];     /* for control responses */
         u32 rd_msg_hdr;
+        u32 wr_msg_buf[128];    /* used for control messages */
+        struct {
+                struct mei_msg_hdr hdr;
+                unsigned char data[4];  /* All HBM messages are 4 bytes */
+        } wr_ext_msg;           /* for control responses */
 
         struct hbm_version version;