[PATCH] s390: qeth bug fixes

[patch 7/10] s390: qeth bug fixes.

From: Frank Pavlic <pavlic@de.ibm.com>

qeth network driver changes:
 - Removed redundant code, use the same qeth_fill_buffer_frag
   for TSO path either
 - Using skb->frags solely is not correct since skb->data still
   points to the beginning of the whole data, even when it is
   a small portion we have to fill the qdio buffer with it.

Signed-off-by: Frank Pavlic <pavlic@de.ibm.com>

1 files changed, 58 insertions, 13 deletions

diff --git a/drivers/s390/net/qeth_tso.h b/drivers/s390/net/qeth_tso.h
index 83504dee3f57..ff585ae49b6c 100644
--- a/drivers/s390/net/qeth_tso.h
+++ b/drivers/s390/net/qeth_tso.h
@@ -1,5 +1,5 @@
 /*
- * linux/drivers/s390/net/qeth_tso.h ($Revision: 1.4 $)
+ * linux/drivers/s390/net/qeth_tso.h ($Revision: 1.5 $)
  *
  * Header file for qeth TCP Segmentation Offload support.
  *
@@ -7,7 +7,7 @@
  *
  *    Author(s): Frank Pavlic <pavlic@de.ibm.com>
  *
- *    $Revision: 1.4 $   $Date: 2005/03/24 09:04:18 $
+ *    $Revision: 1.5 $   $Date: 2005/04/01 21:40:41 $
  *
  */
 #ifndef __QETH_TSO_H__
@@ -37,22 +37,67 @@ struct qeth_hdr_tso {
 } __attribute__ ((packed));
 
 /*some helper functions*/
-
 static inline int
 qeth_get_elements_no(struct qeth_card *card, void *hdr, struct sk_buff *skb)
 {
         int elements_needed = 0;
 
-        if (skb_shinfo(skb)->nr_frags > 0)
-                elements_needed = (skb_shinfo(skb)->nr_frags + 1);
-        if (elements_needed == 0 )
-                elements_needed = 1 + (((((unsigned long) hdr) % PAGE_SIZE)
-                                        + skb->len) >> PAGE_SHIFT);
-        if (elements_needed > QETH_MAX_BUFFER_ELEMENTS(card)){
-                PRINT_ERR("qeth_do_send_packet: invalid size of "
-                          "IP packet. Discarded.");
-                return 0;
+        if (skb_shinfo(skb)->nr_frags > 0)
+                elements_needed = (skb_shinfo(skb)->nr_frags + 1);
+        if (elements_needed == 0 )
+                elements_needed = 1 + (((((unsigned long) hdr) % PAGE_SIZE)
+                                        + skb->len) >> PAGE_SHIFT);
+        if (elements_needed > QETH_MAX_BUFFER_ELEMENTS(card)){
+                PRINT_ERR("qeth_do_send_packet: invalid size of "
+                          "IP packet. Discarded.");
+                return 0;
+        }
+        return elements_needed;
+}
+
+static inline void
+__qeth_fill_buffer_frag(struct sk_buff *skb, struct qdio_buffer *buffer,
+                        int is_tso, int *next_element_to_fill)
+{
+        int length = skb->len;
+        struct skb_frag_struct *frag;
+        int fragno;
+        unsigned long addr;
+        int element;
+        int first_lap = 1;
+
+        fragno = skb_shinfo(skb)->nr_frags; /* start with last frag */
+        element = *next_element_to_fill + fragno;
+        while (length > 0) {
+                if (fragno > 0) {
+                        frag = &skb_shinfo(skb)->frags[fragno - 1];
+                        addr = (page_to_pfn(frag->page) << PAGE_SHIFT) +
+                                frag->page_offset;
+                        buffer->element[element].addr = (char *)addr;
+                        buffer->element[element].length = frag->size;
+                        length -= frag->size;
+                        if (first_lap)
+                                buffer->element[element].flags =
+                                    SBAL_FLAGS_LAST_FRAG;
+                        else
+                                buffer->element[element].flags =
+                                    SBAL_FLAGS_MIDDLE_FRAG;
+                } else {
+                        buffer->element[element].addr = skb->data;
+                        buffer->element[element].length = length;
+                        length = 0;
+                        if (is_tso)
+                                buffer->element[element].flags =
+                                        SBAL_FLAGS_MIDDLE_FRAG;
+                        else
+                                buffer->element[element].flags =
+                                        SBAL_FLAGS_FIRST_FRAG;
+                }
+                element--;
+                fragno--;
+                first_lap = 0;
         }
-        return elements_needed;
+        *next_element_to_fill += skb_shinfo(skb)->nr_frags + 1;
 }
+
 #endif /* __QETH_TSO_H__ */