[SCSI] zfcp: code cleanup

improve code for buffer enqueue. easy readability and maintainability.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 22649639230b25fc8a326ab0eb3938070a9fdb26..b36dfc40d9fa26b41ee3aca598eabe3a9c999bd0 100644 (file)
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -126,6 +126,7 @@ zfcp_address_to_sg(void *address, struct scatterlist *list)
 #define ZFCP_MIN_OUTPUT_THRESHOLD      1       /* ignored by QDIO layer */
 
 #define QDIO_SCSI_QFMT                 1       /* 1 for FSF */
+#define QBUFF_PER_PAGE                 (PAGE_SIZE / sizeof(struct qdio_buffer))
 
 /********************* FSF SPECIFIC DEFINES *********************************/
 

diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index bdf5782b8a7acd175dac262d45514d7035a21bbb..c408badd2ae966c20917bf286951c3b347efb056 100644 (file)
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -47,103 +47,56 @@ static int zfcp_qdio_handler_error_check(struct zfcp_adapter *,
 #define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_QDIO
 
 /*
- * Allocates BUFFER memory to each of the pointers of the qdio_buffer_t 
- * array in the adapter struct.
- * Cur_buf is the pointer array and count can be any number of required 
- * buffers, the page-fitting arithmetic is done entirely within this funciton.
+ * Frees BUFFER memory for each of the pointers of the struct qdio_buffer array
+ * in the adapter struct sbuf is the pointer array.
  *
- * returns:    number of buffers allocated
  * locks:       must only be called with zfcp_data.config_sema taken
  */
-static int
-zfcp_qdio_buffers_enqueue(struct qdio_buffer **cur_buf, int count)
+static void
+zfcp_qdio_buffers_dequeue(struct qdio_buffer **sbuf)
 {
-       int buf_pos;
-       int qdio_buffers_per_page;
-       int page_pos = 0;
-       struct qdio_buffer *first_in_page = NULL;
-
-       qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
-       ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
-
-       for (buf_pos = 0; buf_pos < count; buf_pos++) {
-               if (page_pos == 0) {
-                       cur_buf[buf_pos] = (struct qdio_buffer *)
-                           get_zeroed_page(GFP_KERNEL);
-                       if (cur_buf[buf_pos] == NULL) {
-                               ZFCP_LOG_INFO("error: allocation of "
-                                             "QDIO buffer failed \n");
-                               goto out;
-                       }
-                       first_in_page = cur_buf[buf_pos];
-               } else {
-                       cur_buf[buf_pos] = first_in_page + page_pos;
+       int pos;
 
-               }
-               /* was initialised to zero */
-               page_pos++;
-               page_pos %= qdio_buffers_per_page;
-       }
- out:
-       return buf_pos;
+       for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE)
+               free_page((unsigned long) sbuf[pos]);
 }
 
 /*
- * Frees BUFFER memory for each of the pointers of the struct qdio_buffer array
- * in the adapter struct cur_buf is the pointer array and count can be any
- * number of buffers in the array that should be freed starting from buffer 0
+ * Allocates BUFFER memory to each of the pointers of the qdio_buffer_t
+ * array in the adapter struct.
+ * Cur_buf is the pointer array
  *
+ * returns:    zero on success else -ENOMEM
  * locks:       must only be called with zfcp_data.config_sema taken
  */
-static void
-zfcp_qdio_buffers_dequeue(struct qdio_buffer **cur_buf, int count)
+static int
+zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbuf)
 {
-       int buf_pos;
-       int qdio_buffers_per_page;
-
-       qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
-       ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
+       int pos;
 
-       for (buf_pos = 0; buf_pos < count; buf_pos += qdio_buffers_per_page)
-               free_page((unsigned long) cur_buf[buf_pos]);
-       return;
+       for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) {
+               sbuf[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL);
+               if (!sbuf[pos]) {
+                       zfcp_qdio_buffers_dequeue(sbuf);
+                       return -ENOMEM;
+               }
+       }
+       for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++)
+               if (pos % QBUFF_PER_PAGE)
+                       sbuf[pos] = sbuf[pos - 1] + 1;
+       return 0;
 }
 
 /* locks:       must only be called with zfcp_data.config_sema taken */
 int
 zfcp_qdio_allocate_queues(struct zfcp_adapter *adapter)
 {
-       int buffer_count;
-       int retval = 0;
+       int ret;
 
-       buffer_count =
-           zfcp_qdio_buffers_enqueue(&(adapter->request_queue.buffer[0]),
-                                     QDIO_MAX_BUFFERS_PER_Q);
-       if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
-               ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for request "
-                              "queue\n", buffer_count);
-               zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
-                                         buffer_count);
-               retval = -ENOMEM;
-               goto out;
-       }
-
-       buffer_count =
-           zfcp_qdio_buffers_enqueue(&(adapter->response_queue.buffer[0]),
-                                     QDIO_MAX_BUFFERS_PER_Q);
-       if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
-               ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for response "
-                              "queue", buffer_count);
-               zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
-                                         buffer_count);
-               ZFCP_LOG_TRACE("freeing request_queue buffers\n");
-               zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
-                                         QDIO_MAX_BUFFERS_PER_Q);
-               retval = -ENOMEM;
-               goto out;
-       }
- out:
-       return retval;
+       ret = zfcp_qdio_buffers_enqueue(adapter->request_queue.buffer);
+       if (ret)
+               return ret;
+       return zfcp_qdio_buffers_enqueue(adapter->response_queue.buffer);
 }
 
 /* locks:       must only be called with zfcp_data.config_sema taken */
@@ -151,12 +104,10 @@ void
 zfcp_qdio_free_queues(struct zfcp_adapter *adapter)
 {
        ZFCP_LOG_TRACE("freeing request_queue buffers\n");
-       zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
-                                 QDIO_MAX_BUFFERS_PER_Q);
+       zfcp_qdio_buffers_dequeue(adapter->request_queue.buffer);
 
        ZFCP_LOG_TRACE("freeing response_queue buffers\n");
-       zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
-                                 QDIO_MAX_BUFFERS_PER_Q);
+       zfcp_qdio_buffers_dequeue(adapter->response_queue.buffer);
 }
 
 int