s390/qeth: use mm helpers

Slightly reduce the complexity of the core xmit path, by replacing some
open-coded logic with the corresponding helpers.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index cd9e2f70d8f657a6846a12c0f93f939cd27ded79..feb9e1c9d50693069b18f040888c365f0957023a 100644 (file)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -20,6 +20,7 @@
 #include <linux/ip.h>
 #include <linux/tcp.h>
 #include <linux/mii.h>
+#include <linux/mm.h>
 #include <linux/kthread.h>
 #include <linux/slab.h>
 #include <linux/if_vlan.h>
@@ -3723,8 +3724,8 @@ check_layout:
                        __elements = 1 + qeth_count_elements(skb, proto_len);
                else
                        __elements = qeth_count_elements(skb, 0);
-       } else if (!proto_len && qeth_get_elements_for_range(start, end) == 1) {
-               /* Push HW header into a new page. */
+       } else if (!proto_len && PAGE_ALIGNED(skb->data)) {
+               /* Push HW header into preceding page, flush with skb->data. */
                push_ok = true;
                __elements = 1 + qeth_count_elements(skb, 0);
        } else {
@@ -3778,18 +3779,16 @@ static void __qeth_fill_buffer(struct sk_buff *skb,
        int element = buf->next_element_to_fill;
        int length = skb_headlen(skb) - offset;
        char *data = skb->data + offset;
-       int length_here, cnt;
+       unsigned int elem_length, cnt;
 
        /* map linear part into buffer element(s) */
        while (length > 0) {
-               /* length_here is the remaining amount of data in this page */
-               length_here = PAGE_SIZE - ((unsigned long) data % PAGE_SIZE);
-               if (length < length_here)
-                       length_here = length;
+               elem_length = min_t(unsigned int, length,
+                                   PAGE_SIZE - offset_in_page(data));
 
                buffer->element[element].addr = data;
-               buffer->element[element].length = length_here;
-               length -= length_here;
+               buffer->element[element].length = elem_length;
+               length -= elem_length;
                if (is_first_elem) {
                        is_first_elem = false;
                        if (length || skb_is_nonlinear(skb))
@@ -3802,7 +3801,8 @@ static void __qeth_fill_buffer(struct sk_buff *skb,
                        buffer->element[element].eflags =
                                SBAL_EFLAGS_MIDDLE_FRAG;
                }
-               data += length_here;
+
+               data += elem_length;
                element++;
        }
 
@@ -3813,17 +3813,16 @@ static void __qeth_fill_buffer(struct sk_buff *skb,
                data = skb_frag_address(frag);
                length = skb_frag_size(frag);
                while (length > 0) {
-                       length_here = PAGE_SIZE -
-                               ((unsigned long) data % PAGE_SIZE);
-                       if (length < length_here)
-                               length_here = length;
+                       elem_length = min_t(unsigned int, length,
+                                           PAGE_SIZE - offset_in_page(data));
 
                        buffer->element[element].addr = data;
-                       buffer->element[element].length = length_here;
+                       buffer->element[element].length = elem_length;
                        buffer->element[element].eflags =
                                SBAL_EFLAGS_MIDDLE_FRAG;
-                       length -= length_here;
-                       data += length_here;
+
+                       length -= elem_length;
+                       data += elem_length;
                        element++;
                }
        }