Subject: [PATCH] zfcp: code cleanup
From: Swen Schillig <swen@xxxxxxxxxxxx>
improve code for buffer enqueue. easy readability and maintainability.
Signed-off-by: Swen Schillig <swen@xxxxxxxxxxxx>
---
drivers/s390/scsi/zfcp_def.h | 1
drivers/s390/scsi/zfcp_qdio.c | 113 +++++++++++-------------------------------
2 files changed, 33 insertions(+), 81 deletions(-)
diff -urpN linux-2.6/drivers/s390/scsi/zfcp_def.h linux-2.6-patched/drivers/s390/scsi/zfcp_def.h
--- linux-2.6/drivers/s390/scsi/zfcp_def.h 2007-07-09 01:32:17.000000000 +0200
+++ linux-2.6-patched/drivers/s390/scsi/zfcp_def.h 2007-07-18 10:28:26.000000000 +0200
@@ -126,6 +126,7 @@ zfcp_address_to_sg(void *address, struct
#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 -urpN linux-2.6/drivers/s390/scsi/zfcp_qdio.c linux-2.6-patched/drivers/s390/scsi/zfcp_qdio.c
--- linux-2.6/drivers/s390/scsi/zfcp_qdio.c 2007-07-09 01:32:17.000000000 +0200
+++ linux-2.6-patched/drivers/s390/scsi/zfcp_qdio.c 2007-07-18 10:28:26.000000000 +0200
@@ -47,103 +47,56 @@ static int zfcp_qdio_handler_error_check
#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
-
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